Inactivated rotavirus vaccine induces protective immunity in gnotobiotic piglets.

PubMed

Wang, Yuhuan; Azevedo, Marli; Saif, Linda J; Gentsch, Jon R; Glass, Roger I; Jiang, Baoming

2010-07-26

Live oral rotavirus vaccines that are effective in middle and high income countries have been much less immunogenic and effective among infants in resource-limited settings. Several hypotheses might explain this difference, including neutralization of the vaccine by high levels of maternal antibody in serum and breast milk, severe malnutrition, and interference by other flora and viruses in the gut. We have pursued development of an alternative parenteral rotavirus vaccine with the goal of inducing comparable levels of immunogenicity and efficacy in populations throughout the world regardless of their income levels. In the present study, we assessed the immunogenicity and protection of a candidate inactivated rotavirus vaccine (IRV), the human strain CDC-9 (G1P[8]) formulated with aluminum phosphate, against rotavirus infection in gnotobiotic piglets. Three doses of IRV induced high titers of rotavirus-specific IgG and neutralizing activity in the sera of gnotobiotic piglets and protection against shedding of rotavirus antigen following oral challenge with a homologous virulent human strain Wa (G1P[8]). Our findings demonstrate the proof of concept for an IRV in a large animal model and provide evidence and justification for further clinical development as an alternative candidate vaccine. Published by Elsevier Ltd.

Spatial organization of a model 15-member human gut microbiota established in gnotobiotic mice

PubMed Central

Mark Welch, Jessica L.; Hasegawa, Yuko; McNulty, Nathan P.; Gordon, Jeffrey I.; Borisy, Gary G.

2017-01-01

Knowledge of the spatial organization of the gut microbiota is important for understanding the physical and molecular interactions among its members. These interactions are thought to influence microbial succession, community stability, syntrophic relationships, and resiliency in the face of perturbations. The complexity and dynamism of the gut microbiota pose considerable challenges for quantitative analysis of its spatial organization. Here, we illustrate an approach for addressing this challenge, using (i) a model, defined 15-member consortium of phylogenetically diverse, sequenced human gut bacterial strains introduced into adult gnotobiotic mice fed a polysaccharide-rich diet, and (ii) in situ hybridization and spectral imaging analysis methods that allow simultaneous detection of multiple bacterial strains at multiple spatial scales. Differences in the binding affinities of strains for substrates such as mucus or food particles, combined with more rapid replication in a preferred microhabitat, could, in principle, lead to localized clonally expanded aggregates composed of one or a few taxa. However, our results reveal a colonic community that is mixed at micrometer scales, with distinct spatial distributions of some taxa relative to one another, notably at the border between the mucosa and the lumen. Our data suggest that lumen and mucosa in the proximal colon should be conceptualized not as stratified compartments but as components of an incompletely mixed bioreactor. Employing the experimental approaches described should allow direct tests of whether and how specified host and microbial factors influence the nature and functional contributions of “microscale” mixing to the dynamic operations of the microbiota in health and disease. PMID:29073107

Evaluation of induction of porcine dermatitis and nephropathy syndrome in gnotobiotic pigs with negative results for porcine circovirus type 2.

PubMed

Krakowka, Steven; Hartunian, Catherine; Hamberg, Alexander; Shoup, David; Rings, Michael; Zhang, Yan; Allan, Gordon; Ellis, John A

2008-12-01

To determine whether porcine dermatitis and nephropathy syndrome (PDNS) could be experimentally induced in gnotobiotic swine. Plasma samples from 27 sows and 20 conventional weaned piglets were obtained, and 30 gnotobiotic pigs were used in experiments. 3 experiments were conducted. Groups of 3-day-old gnotobiotic pigs were inoculated with pooled plasma samples obtained from healthy feeder pigs in a herd that was in the initial phases of an outbreak of respiratory disease; gross and histologic lesions of PDNS were detected in the inoculated pigs. In a second experiment, 2- and 3-day-old gnotobiotic pigs were inoculated with porcine reproductive respiratory syndrome virus (PRRSV) and with PRRSV-negative tissue homogenate containing genogroup 1 torque teno virus (g1-TTV). Lesions of PDNS were detected. Pigs inoculated with pooled plasma or the combination of tissue-culture-origin PRRSV and g1-TTV tissue homogenate developed systemic hemostatic defects, bilaterally symmetric cutaneous hemorrhages, generalized edema, icterus, bilaterally symmetric renal cortical hemorrhage, dermal vasculitis with hemorrhage, and interstitial pneumonia consistent with a clinical and pathologic diagnosis of PDNS. The PRRSV RNAs and g1-TTV DNAs were detected in plasma; all pigs seroconverted to PRRSV, and all had negative results for porcine circovirus type 2 when tested by use of PCR assays. These data suggested that PDNS is a manifestation of disseminated intravascular coagulation in swine. For the experimental conditions reported here, combined infection with g1-TTV and PRRSV was implicated in the genesis of these lesions.

Development of the gut microbiota and mucosal IgA responses in twins and gnotobiotic mice

PubMed Central

Planer, Joseph D.; Peng, Yangqing; Kau, Andrew L.; Blanton, Laura V.; Ndao, I. Malick; Tarr, Phillip I.; Warner, Barbara B.; Gordon, Jeffrey I.

2016-01-01

Immunoglobulin A (IgA), the major class of antibody secreted by the gut mucosa, is an important contributor to gut barrier function1–3. The repertoire of IgA bound to gut bacteria reflects both T cell-dependent and -independent pathways4,5, plus glycans present on the antibody’s secretory component6. Human gut bacterial taxa targeted by IgA in the setting of intestinal barrier dysfunction are capable of producing intestinal pathology when isolated and transferred to gnotobiotic mice7,8. A complex reorientation of gut immunity occurs as infants transition from passively acquired IgA present in breast milk to host-derived IgA9–11. How IgA responses co-develop with assembly of the microbiota during this period remains poorly understood. Here, we (i) identify a set of age-discriminatory bacterial taxa whose representations define a program of microbiota assembly/maturation during the first 2 postnatal years that is shared across 40 healthy USA twin pairs; (ii) describe a pattern of progression of gut mucosal IgA responses to bacterial members of the microbiota that is highly distinctive for family members (twin pairs) during the first several postnatal months then generalizes across pairs in the second year; and (iii) assess the effects of zygosity, birth mode and breast feeding. Age-associated differences in these IgA responses can be recapitulated in young germ-free mice, colonized with fecal microbiota obtained from two twin pairs at 6 and 18 months of age, and fed a sequence of human diets that simulate the transition from milk feeding to complementary foods. The majority of these responses were robust to diet suggesting that ‘intrinsic’ properties of community members play a dominant role in dictating IgA responses. The approach described can be used to define gut mucosal immune development in health and disease states and help discover ways for repairing or preventing perturbations in this facet of host immunity. PMID:27279225

Development of the gut microbiota and mucosal IgA responses in twins and gnotobiotic mice.

PubMed

Planer, Joseph D; Peng, Yangqing; Kau, Andrew L; Blanton, Laura V; Ndao, I Malick; Tarr, Phillip I; Warner, Barbara B; Gordon, Jeffrey I

2016-06-09

Immunoglobulin A (IgA), the major class of antibody secreted by the gut mucosa, is an important contributor to gut barrier function. The repertoire of IgA bound to gut bacteria reflects both T-cell-dependent and -independent pathways, plus glycans present on the antibody's secretory component. Human gut bacterial taxa targeted by IgA in the setting of barrier dysfunction are capable of producing intestinal pathology when isolated and transferred to gnotobiotic mice. A complex reorientation of gut immunity occurs as infants transition from passively acquired IgA present in breast milk to host-derived IgA. How IgA responses co-develop with assembly of the microbiota during this period remains poorly understood. Here, we (1) identify a set of age-discriminatory bacterial taxa whose representations define a program of microbiota assembly and maturation during the first 2 postnatal years that is shared across 40 healthy twin pairs in the USA; (2) describe a pattern of progression of gut mucosal IgA responses to bacterial members of the microbiota that is highly distinctive for family members (twin pairs) during the first several postnatal months then generalizes across pairs in the second year; and (3) assess the effects of zygosity, birth mode, and breast feeding. Age-associated differences in these IgA responses can be recapitulated in young germ-free mice, colonized with faecal microbiota obtained from two twin pairs at 6 and 18 months of age, and fed a sequence of human diets that simulate the transition from milk feeding to complementary foods. Most of these responses were robust to diet, suggesting that 'intrinsic' properties of community members play a dominant role in dictating IgA responses. The approach described can be used to define gut mucosal immune development in health and disease states and to help discover ways of repairing or preventing perturbations in this facet of host immunity.

Best practices for germ-free derivation and gnotobiotic zebrafish husbandry

PubMed Central

Melancon, E.; De La Torre Canny, S. Gomez; Sichel, S.; Kelly, M.; Wiles, T.J.; Rawls, J.F.; Eisen, J.S.; Guillemin, K.

2017-01-01

All animals are ecosystems with resident microbial communities, referred to as microbiota, which play profound roles in host development, physiology, and evolution. Enabled by new DNA sequencing technologies, there is a burgeoning interest in animal–microbiota interactions, but dissecting the specific impacts of microbes on their hosts is experimentally challenging. Gnotobiology, the study of biological systems in which all members are known, enables precise experimental analysis of the necessity and sufficiency of microbes in animal biology by deriving animals germ-free (GF) and inoculating them with defined microbial lineages. Mammalian host models have long dominated gnotobiology, but we have recently adapted gnotobiotic approaches to the zebrafish (Danio rerio), an important aquatic model. Zebrafish offer several experimental attributes that enable rapid, large-scale gnotobiotic experimentation with high replication rates and exquisite optical resolution. Here we describe detailed protocols for three procedures that form the foundation of zebrafish gnotobiology: derivation of GF embryos, microbial association of GF animals, and long-term, GF husbandry. Our aim is to provide sufficient guidance in zebrafish gnotobiotic methodology to expand and enrich this exciting field of research. PMID:28129860

The Role of the Gut Microbiota in the Metabolism of Polyphenols as Characterized by Gnotobiotic Mice

PubMed Central

Pasinetti, Giulio Maria; Singh, Risham; Westfall, Susan; Herman, Francis; Faith, Jeremiah; Ho, Lap

2018-01-01

A growing body of experimental data suggests that microbes in the gut influence behavior and can alter brain physiology and neurochemistry. Although promising, researchers are only starting to understand the potential of the gut microbiota for use in neurological disease. Recent evidence demonstrated that gastrointestinal activities are linked to mood disorders such as anxiety, depression, and most recently, cognitive functions in age-related neurodegenerative disorders. Studies from our group and others are uncovering new evidence suggesting that the gut microbiota plays a crucial role in the metabolism and bioavailability of certain dietary compounds and synthetic drugs. Based on this evidence, this review article will discuss the implications of the gut microbiota in mechanisms of bioavailability and biotransformation with an emphasis on dietary polyphenol compounds. This will be followed by a survey of ongoing innovative research identifying the ability of individual gut bacteria to enhance the bioavailability of gut-derived, brain-penetrating, bioactive polyphenol metabolites that ultimately influence mechanisms associated with the promotion of resilience against psychological and cognitive impairment in response to stress. Lastly, current research initiatives aimed at promoting the generation of brain bioactive polyphenol metabolites by specialized gut microbes will be discussed, specifically the use of gnotobiotic mice to develop bioengineered second generation probiotics. We propose that leveraging the gut microbial ecosystem to generate brain targeted bioactive metabolites from dietary polyphenols can attenuate lifestyle risk factors and promote resilience against age-related cognitive decline. PMID:29660942

[Antagonistic interaction between Clostridium butyricum and enterohemorrhagic Escherichia coli O157:H7].

PubMed

Takahashi, M; Taguchi, H; Yamaguchi, H; Osaki, T; Sakazaki, R; Kamiya, S

1999-01-01

Antagonistic interaction between Clostridium butyricum strain MIYAIRI 588 and enterohemorrhagic Esherichia coli (EHEC) strain O157:H7 006 was examined using streptomycin-treated SPF mice and germ free mice. All SPF mice pretreated with streptomycin were colonized with EHEC O157:H7. On the other hand, only 20% of the SPF mice pretreated with streptomycin and C. butyricum were colonized with EHEC O157:H7. In addition, germ free mice died within 4-7 days after infection with EHEC O157:H7. In contrast, all gnotobiotic mice mono-associated with C. butyricum survived after the challenge with EHEC O157:H7. Both the number of EHEC and the amounts of shiga-like cytotoxin (SLT, type 1 and type 2) in fecal contents of gnotobiotic mice treated with C. butyricum were less than those of mice infected with only EHEC O157:H7. In conclusion, the probiotic bacterium, C. butyricum strain MIYAIRI 588, has a preventive effect against EHEC O157:H7 infection.

Experimental Shigella Infections in Laboratory Animals I. Antagonism by Human Normal Flora Components in Gnotobiotic Mice 12

PubMed Central

Maier, Bruce R.; Hentges, David J.

1972-01-01

Germfree mice were associated with selected species of human intestinal bacteria and then challenged with a streptomycin-resistant Shigella flexneri strain. Antagonism against Shigella was most pronounced in mice associated with Escherichia coli and least pronounced in mice associated with Bacteroides fragilis. A moderate degree of antagonism could be demonstrated in mice associated with either Streptococcus faecalis or Bifidobacterium adolescentis. Shigella persisted in the cecal contents of E. coli-associated mice at very low, stable levels. Shigella populations were reduced to levels below detection in the ceca of mice diassociated with E. coli and Bacteroides. Upon subsequent administration of streptomycin, Bacteroides disappeared from the ceca. The E. coli population was greatly reduced, and Shigella reappeared at very high population levels as an apparent recombinant which resembled E. coli biochemically. A streptomycin-resistant E. coli population subsequently emerged and became dominant in the ceca. Shigella concomitantly declined to levels below detection. PMID:4631914

Skin Vaccination against Rotavirus Using Microneedles: Proof of Concept in Gnotobiotic Piglets

PubMed Central

Wang, Yuhuan; Vlasova, Anastasia; Velasquez, Daniel E.; Saif, Linda J.; Kandasamy, Sukumar; Kochba, Efrat; Levin, Yotam; Jiang, Baoming

2016-01-01

Live-attenuated oral rotavirus (RV) vaccines have lower efficacy in low income countries, and additionally are associated with a rare but severe adverse event, intussusception. We have been pursuing the development of an inactivated rotavirus vaccine (IRV) using the human rotavirus strain CDC-9 (G1P[8]) through parenteral immunization and previously demonstrated dose sparing and enhanced immunogenicity of intradermal (ID) unadjuvanted IRV using a coated microneedle patch in comparison with intramuscular (IM) administration in mice. The aim of this study was to evaluate the immune response and protection against RV infection and diarrhea conferred by the administration of the ID unadjuvanted IRV using the microneedle device MicronJet600® in neonatal gnotobiotic (Gn) piglets challenged with virulent Wa G1P[8] human RV. Three doses of 5 μg IRV when administered intradermally and 5 μg IRV formulated with aluminum hydroxide [Al(OH)3] when administered intramuscularly induced comparable rotavirus-specific antibody titers of IgA, IgG, IgG avidity index and neutralizing activity in sera of neonatal piglets. Both IRV vaccination regimens protected against RV antigen shedding in stools, and reduced the cumulative diarrhea scores in the piglets. This study demonstrated that the ID and IM administrations of IRV are immunogenic and protective against RV-induced diarrhea in neonatal piglets. Our findings highlight the potential value of an adjuvant sparing effect of the IRV ID delivery route. PMID:27824918

Skin Vaccination against Rotavirus Using Microneedles: Proof of Concept in Gnotobiotic Piglets.

PubMed

Wang, Yuhuan; Vlasova, Anastasia; Velasquez, Daniel E; Saif, Linda J; Kandasamy, Sukumar; Kochba, Efrat; Levin, Yotam; Jiang, Baoming

2016-01-01

Live-attenuated oral rotavirus (RV) vaccines have lower efficacy in low income countries, and additionally are associated with a rare but severe adverse event, intussusception. We have been pursuing the development of an inactivated rotavirus vaccine (IRV) using the human rotavirus strain CDC-9 (G1P[8]) through parenteral immunization and previously demonstrated dose sparing and enhanced immunogenicity of intradermal (ID) unadjuvanted IRV using a coated microneedle patch in comparison with intramuscular (IM) administration in mice. The aim of this study was to evaluate the immune response and protection against RV infection and diarrhea conferred by the administration of the ID unadjuvanted IRV using the microneedle device MicronJet600® in neonatal gnotobiotic (Gn) piglets challenged with virulent Wa G1P[8] human RV. Three doses of 5 μg IRV when administered intradermally and 5 μg IRV formulated with aluminum hydroxide [Al(OH)3] when administered intramuscularly induced comparable rotavirus-specific antibody titers of IgA, IgG, IgG avidity index and neutralizing activity in sera of neonatal piglets. Both IRV vaccination regimens protected against RV antigen shedding in stools, and reduced the cumulative diarrhea scores in the piglets. This study demonstrated that the ID and IM administrations of IRV are immunogenic and protective against RV-induced diarrhea in neonatal piglets. Our findings highlight the potential value of an adjuvant sparing effect of the IRV ID delivery route.

Viral wasting syndrome of swine: experimental reproduction of postweaning multisystemic wasting syndrome in gnotobiotic swine by coinfection with porcine circovirus 2 and porcine parvovirus.

PubMed

Krakowka, S; Ellis, J A; Meehan, B; Kennedy, S; McNeilly, F; Allan, G

2000-05-01

One-day-old gnotobiotic piglets were inoculated intranasally with in vitro passaged porcine circovirus 1 (PCV-1), PCV-2, and porcine parvovirus (PPV) alone or in combination (PCV-1/PCV-2, PCV-1/PPV, and PCV-2/PPV). Piglets were evaluated for 1) the development of porcine postweaning multisystemic wasting syndrome (PMWS), 2) distribution of viral antigens by immunochemistry, and 3) viremia and the presence of viral DNA in nasal and ocular secretions and feces. All single agent-infected piglets and piglets infected with PCV-1/PCV-2 or PCV-1/PPV were clinically asymptomatic. They were transiently viremic and seroconverted to homologous virus(es). At termination of the study on postinfection day (PID) 35, microscopic lesions were restricted to focal inflammatory cell infiltrates in livers and myocardia. One piglet given PCV-1/PPV was PPV viremic for 2 weeks after infection and had lymphangiectasia of the spiral and descending colon associated with granulomatous inflammation. All four PCV-2/PPV-inoculated piglets developed PMWS, characterized by sudden onset of depression and anorexia, icterus, and submucosal edema. One piglet became moribund on PID 27, and the remaining three piglets were euthanatized between PID 27 and PID 30 because of severe disease. Lymph nodes were small and the livers were mottled. Disseminated angiocentric granulomatous inflammation was present in all tissues examined except the brain. Multiple lightly basophilic intracytoplasmic inclusion bodies were identified in macrophages and histiocytes. PCV-2 antigen was widely distributed within macrophages; PPV antigen was sparse. Hepatocellular necrosis and bile retention were prominent. PCV-2 DNA was identified in ocular, fecal, and nasal secretions. Terminal sera contained antibodies to PPV (4/4) and PCV-2 (3/ 4). Production of PMWS in gnotobiotic swine appears to require PCV-2 and additional infectious agents such as PPV for full disease expression in gnotobiotic piglets.

Swine dysentery: inoculation of gnotobiotic pigs with Treponema hyodysenteriae and Vibrio coli and a Peptostreptococcus.

PubMed Central

Brandenburg, A C; Miniats, O P; Geissinger, H D; Ewert, E

1977-01-01

Pure cultures of Treponema hyodysenteriae given orally to conventional pigs resulted in the development of swine dysentery, whereas identical cultures given to gnotobiotic pigs did not produce the disease. Oral inoculation of gnotobiotic pigs with Vibrio coli and/or a peptostreptococcus in addition to T. hyodysenteriae did not result in dysentery. Neutralization of gastric secretions with NaHCO3 immediately prior to inoculation with T. hyodysenteriae increased the period during which treponemes were evident in the feces, as did the inoculation of this organism via the intracecal route. None of the gnotobiotic pigs with a persistent fecal Treponema population developed signs of dysentery. Factors other than those investigated in this work must play a part in the etiology of swine dysentery. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:907906

Susceptibility of thermally injured mice to cytomegalovirus infection.

PubMed

Kobayashi, H; Kobayashi, M; Herndon, D N; Pollard, R B; Suzuki, F

2001-11-01

Thermally injured patients are very susceptible to infection with cytomegaloviruses. In this study a role of burn-associated type 2 T cell responses on the cytomegalovirus infection was examined in a mouse model of thermal injury. A predominance of type 2 T cell responses in splenic lymphocytes of thermally injured mice has been previously demonstrated. SCID mice inoculated with splenic T cells from thermally injured mice were susceptible to infection with a small amount (5 PFU/mouse) of murine cytomegalovirus (MCMV). Conversely, SCID mice inoculated with splenic T cells from normal mice were resistant to the same infection. High levels of IL-4 and IL-10, but not IFN-gamma and IL-2, were detected in sera of thermally injured mice (TI-mice) infected with MCMV when those were compared with sera of normal mice infected with MCMV. IL-4 and IL-10 (type 2 cytokines) were produced by splenic T cells from MCMV-infected TI-mice, when they were stimulated in vitro with anti-CD3 mAb. Type 1 cytokines (IFN-gamma and IL-2), however, were not produced by these T cells after the same stimulation. In contrast, splenic T cells from MCMV-infected normal mice produced type 1 cytokines by the stimulation with anti-CD3 mAb. These results suggest that the susceptibility of mice to MCMV infection is markedly influenced by burn-associated type 2 T cell responses.

Mycoplasma hyopneumoniae bacterins and porcine circovirus type 2 (PCV2) infection: Induction of postweaning multisystemic wasting syndrome (PMWS) in the gnotobiotic swine model of PCV2-associated disease

PubMed Central

Krakowka, Steven; Ellis, John; McNeilly, Francis; Waldner, Cheryl; Rings, D. Michael; Allan, Gordon

2007-01-01

Groups (5 to 15 per group) of gnotobiotic swine were infected oronasally with porcine circovirus type 2 (PCV2) at 3 days of age and then given 1 of 6 different commercial Mycoplasma hyopneumoniae (M. hyopneumoniae) bacterins as either a single dose (7 d of age, 1 application products) or 2 doses (7 and 21 d of age, 2 application product). Control groups received PCV2 alone (n = 9) or were infected with PCV2 and immunized twice with keyhole limpet hemocyanin (KLH) emulsified in incomplete Freund’s adjuvant (ICFA) (n = 7). Five of 7 (71%) PCV2-infected piglets immunized with KLH/ICFA developed mild or overt PMWS, whereas none of 9 piglets infected with PCV2 alone developed PMWS. Five of 12 (42%) piglets vaccinated with a commercial bacterin containing mineral oil adjuvant developed PMWS following vaccination. None of the PCV2-infected piglets in the other bacterin-vaccinated groups developed PMWS in this model of PCV2-associated disease. This difference in prevalence of PMWS in piglets given the mineral oil-adjuvanted M. hyopneumoniae bacterin and the other M. hyopneumoniae bacterin vaccination groups was statistically significant (P < 0.05). PMID:17824156

Pathogenicity of porcine intestinal spirochetes in gnotobiotic pigs.

PubMed Central

Neef, N A; Lysons, R J; Trott, D J; Hampson, D J; Jones, P W; Morgan, J H

1994-01-01

Twelve intestinal spirochete strains of porcine origin were characterized on the basis of their phenotypic properties, by multilocus enzyme electrophoresis, and by pathogenicity testing in gnotobiotic pigs. The spirochetes used included two strains of Serpulina hyodysenteriae (B204 and P18A), two strains of Serpulina innocens (B256 and 4/71), one strain from the proposed new genus and species "Anguillina coli" (P43/6/78), and seven non-S. hyodysenteriae strains recently isolated from United Kingdom pig herds with a history of nonspecific diarrhea and typhlocolitis. By multilocus enzyme electrophoresis, five of these were identified as S. innocens, one was identified as an unspecified Serpulina sp., and one was identified as "A. coli." S. hyodysenteriae B204 and P18A, "A. coli" P43/6/78 and 2/7, and three (22/7, P280/1, and 14/5) of the five S. innocens field isolates induced mucoid feces and typhlocolitis in gnotobiotic pigs. None of the other spirochetes produced clinical signs or large intestinal pathology in this model. The "A. coli" strains induced a more watery diarrhea, with lesions present more proximally in the large intestine, than did the other pathogenic spirochetes. S. innocens 22/7 was also tested for pathogenicity in hysterotomy-derived pigs that had previously been artificially colonized with a spirochete-free intestinal flora and shown to be susceptible to swine dysentery. Despite effective colonization, strain 22/7 did not produce any disease, nor was there any exacerbation of large intestinal pathology or clinical signs when pigs with an experimentally induced existing colitis caused by Yersinia pseudotuberculosis were superinfected with strain 22/7. Certain non-S. hyodysenteriae spirochetes are therefore capable of inducing disease in gnotobiotic pigs, but their role as primary or opportunistic pathogens in conventional pigs remains equivocal. Images PMID:8188364

Pathogenicity of porcine intestinal spirochetes in gnotobiotic pigs.

PubMed

Neef, N A; Lysons, R J; Trott, D J; Hampson, D J; Jones, P W; Morgan, J H

1994-06-01

Twelve intestinal spirochete strains of porcine origin were characterized on the basis of their phenotypic properties, by multilocus enzyme electrophoresis, and by pathogenicity testing in gnotobiotic pigs. The spirochetes used included two strains of Serpulina hyodysenteriae (B204 and P18A), two strains of Serpulina innocens (B256 and 4/71), one strain from the proposed new genus and species "Anguillina coli" (P43/6/78), and seven non-S. hyodysenteriae strains recently isolated from United Kingdom pig herds with a history of nonspecific diarrhea and typhlocolitis. By multilocus enzyme electrophoresis, five of these were identified as S. innocens, one was identified as an unspecified Serpulina sp., and one was identified as "A. coli." S. hyodysenteriae B204 and P18A, "A. coli" P43/6/78 and 2/7, and three (22/7, P280/1, and 14/5) of the five S. innocens field isolates induced mucoid feces and typhlocolitis in gnotobiotic pigs. None of the other spirochetes produced clinical signs or large intestinal pathology in this model. The "A. coli" strains induced a more watery diarrhea, with lesions present more proximally in the large intestine, than did the other pathogenic spirochetes. S. innocens 22/7 was also tested for pathogenicity in hysterotomy-derived pigs that had previously been artificially colonized with a spirochete-free intestinal flora and shown to be susceptible to swine dysentery. Despite effective colonization, strain 22/7 did not produce any disease, nor was there any exacerbation of large intestinal pathology or clinical signs when pigs with an experimentally induced existing colitis caused by Yersinia pseudotuberculosis were superinfected with strain 22/7. Certain non-S. hyodysenteriae spirochetes are therefore capable of inducing disease in gnotobiotic pigs, but their role as primary or opportunistic pathogens in conventional pigs remains equivocal.

Torticollis in Mice Intravenously Infected with Mycobacterium tuberculosis

PubMed Central

Magden, Elizabeth R; Weiner, Cristina M; Gilliland, Janet C; DeGroote, Mary Ann; Lenaerts, Anne J; Kendall, Lon V

2011-01-01

Female BALB/cAnNCrl (n = 170; age, 6 to 9 wk) mice were infected by intravenous inoculation of 5 × 106 cfu Mycobacterium tuberculosis strain Erdman (ATCC 35801). Between day 52 and 5 mo after infection, 10 of the 170 mice infected according to this protocol developed torticollis, including mice in treatment groups that received combination antibiotic therapy of rifampin–pyrazinamide or moxifloxacin–rifampin–pyrazinamide. Torticollis did not develop in mice receiving isoniazid–rifampin–pyrazinamide therapy, nor was it present in the cohort of aerogenically infected mice. Affected mice were euthanized, and complete necropsy evaluation was performed on 4 mice. Gross necropsy evaluation revealed typical tuberculosis lesions in lungs of infected mice. Histologic evaluation of tissues revealed granulomatous otitis media with intralesional acid-fast bacilli consistent with Mycobacterium tuberculosis. These cases represent an unusual finding specific to the intravenous mouse model of Mycobacterium tuberculosis and may represent a model of a similar condition in humans that is known as tuberculous otitis media. PMID:21439219

Torticollis in mice intravenously infected with Mycobacterium tuberculosis.

PubMed

Magden, Elizabeth R; Weiner, Cristina M; Gilliland, Janet C; DeGroote, Mary Ann; Lenaerts, Anne J; Kendall, Lon V

2011-03-01

Female BALB/cAnNCrl (n = 170; age, 6 to 9 wk) mice were infected by intravenous inoculation of 5 × 10(6) cfu Mycobacterium tuberculosis strain Erdman (ATCC 35801). Between day 52 and 5 mo after infection, 10 of the 170 mice infected according to this protocol developed torticollis, including mice in treatment groups that received combination antibiotic therapy of rifampin-pyrazinamide or moxifloxacin-rifampin-pyrazinamide. Torticollis did not develop in mice receiving isoniazid- rifampin-pyrazinamide therapy, nor was it present in the cohort of aerogenically infected mice. Affected mice were euthanized, and complete necropsy evaluation was performed on 4 mice. Gross necropsy evaluation revealed typical tuberculosis lesions in lungs of infected mice. Histologic evaluation of tissues revealed granulomatous otitis media with intralesional acid-fast bacilli consistent with Mycobacterium tuberculosis. These cases represent an unusual finding specific to the intravenous mouse model of Mycobacterium tuberculosis and may represent a model of a similar condition in humans that is known as tuberculous otitis media.

Colonization potential to reconstitute a microbe community in patients detected early after fecal microbe transplant for recurrent C. difficile.

PubMed

Kumar, Ranjit; Maynard, Craig L; Eipers, Peter; Goldsmith, Kelly T; Ptacek, Travis; Grubbs, J Aaron; Dixon, Paula; Howard, Donna; Crossman, David K; Crowley, Michael R; Benjamin, William H; Lefkowitz, Elliot J; Weaver, Casey T; Rodriguez, J Martin; Morrow, Casey D

2016-01-13

Fecal microbiota transplants (FMT) are an effective treatment for patients with gut microbe dysbiosis suffering from recurrent C. difficile infections. To further understand how FMT reconstitutes the patient's gut commensal microbiota, we have analyzed the colonization potential of the donor, recipient and recipient post transplant fecal samples using transplantation in gnotobiotic mice. A total of nine samples from three human donors, recipient's pre and post FMT were transplanted into gnotobiotic mice. Microbiome analysis of three donor fecal samples revealed the presence of a high relative abundance of commensal microbes from the family Bacteriodaceae and Lachnospiraceae that were almost absent in the three recipient pre FMT fecal samples (<0.01%). The microbe composition in gnotobiotic mice transplanted with the donor fecal samples was similar to the human samples. The recipient samples contained Enterobacteriaceae, Lactobacillaceae, Enterococcaceae in relative abundance of 43, 11, 8%, respectively. However, gnotobiotic mice transplanted with the recipient fecal samples had an average relative abundance of unclassified Clostridiales of 55%, approximately 7000 times the abundance in the recipient fecal samples prior to transplant. Microbiome analysis of fecal samples from the three patients early (2-4 weeks) after FMT revealed a microbe composition with the relative abundance of both Bacteriodaceae and Lachnospiraceae that was approximately 7% of that of the donor. In contrast, gnotobioitc mice transplanted with the fecal samples obtained from the three at early times post FMT revealed increases in the relative abundance of Bacteriodaceae and Lachnospiraceae microbe compositions to levels similar to the donor fecal samples. Furthermore, the unclassified Clostridiales in the recipient samples post FMT was reduced to an average of 10%. We have used transplantation into gnotobiotic mice to evaluate the colonization potential of microbiota in FMT patients early

Bacterial infection causes stress-induced memory dysfunction in mice.

PubMed

Gareau, Mélanie G; Wine, Eytan; Rodrigues, David M; Cho, Joon Ho; Whary, Mark T; Philpott, Dana J; Macqueen, Glenda; Sherman, Philip M

2011-03-01

The brain-gut axis is a key regulator of normal intestinal physiology; for example, psychological stress is linked to altered gut barrier function, development of food allergies and changes in behaviour. Whether intestinal events, such as enteric bacterial infections and bacterial colonisation, exert a reciprocal effect on stress-associated behaviour is not well established. To determine the effects of either acute enteric infection or absence of gut microbiota on behaviour, including anxiety and non-spatial memory formation. Behaviour was assessed following infection with the non-invasive enteric pathogen, Citrobacter rodentium in both C57BL/6 mice and germ-free Swiss-Webster mice, in the presence or absence of acute water avoidance stress. Whether daily treatment with probiotics normalised behaviour was assessed, and potential mechanisms of action evaluated. No behavioural abnormalities were observed, either at the height of infection (10 days) or following bacterial clearance (30 days), in C rodentium-infected C57BL/6 mice. When infected mice were exposed to acute stress, however, memory dysfunction was apparent after infection (10 days and 30 days). Memory dysfunction was prevented by daily treatment of infected mice with probiotics. Memory was impaired in germ-free mice, with or without exposure to stress, in contrast to conventionally reared, control Swiss-Webster mice with an intact intestinal microbiota. The intestinal microbiota influences the ability to form memory. Memory dysfunction occurs in infected mice exposed to acute stress, while in the germ-free setting memory is altered at baseline.

Active Viremia in Rotavirus-Infected Mice

PubMed Central

Blutt, Sarah E.; Fenaux, Martijn; Warfield, Kelly L.; Greenberg, Harry B.; Conner, Margaret E.

2006-01-01

Rotavirus circulates extraintestinally in animals used as models for rotavirus infection and in children. Rotavirus infection in mice was used to define host or viral factors that affect rotavirus viremia. Antigenemia was observed with homologous and heterologous rotaviruses, and neither age nor mouse strain genetics altered the occurrence of rotavirus antigenemia or viremia. Rotavirus RNA and infectious virus were present in sera and associated with the plasma fraction of blood in all infected mice. These findings indicate that antigenemia/viremia occurs routinely in rotavirus infections and imply that infectious rotavirus has access to any extraintestinal cell within contact of blood. PMID:16775359

Functional Intestinal Bile Acid 7α-Dehydroxylation by Clostridium scindens Associated with Protection from Clostridium difficile Infection in a Gnotobiotic Mouse Model.

PubMed

Studer, Nicolas; Desharnais, Lyne; Beutler, Markus; Brugiroux, Sandrine; Terrazos, Miguel A; Menin, Laure; Schürch, Christian M; McCoy, Kathy D; Kuehne, Sarah A; Minton, Nigel P; Stecher, Bärbel; Bernier-Latmani, Rizlan; Hapfelmeier, Siegfried

2016-01-01

Bile acids, important mediators of lipid absorption, also act as hormone-like regulators and as antimicrobial molecules. In all these functions their potency is modulated by a variety of chemical modifications catalyzed by bacteria of the healthy gut microbiota, generating a complex variety of secondary bile acids. Intestinal commensal organisms are well-adapted to normal concentrations of bile acids in the gut. In contrast, physiological concentrations of the various intestinal bile acid species play an important role in the resistance to intestinal colonization by pathogens such as Clostridium difficile . Antibiotic therapy can perturb the gut microbiota and thereby impair the production of protective secondary bile acids. The most important bile acid transformation is 7α-dehydroxylation, producing deoxycholic acid (DCA) and lithocholic acid (LCA). The enzymatic pathway carrying out 7α-dehydroxylation is restricted to a narrow phylogenetic group of commensal bacteria, the best-characterized of which is Clostridium scindens . Like many other intestinal commensal species, 7-dehydroxylating bacteria are understudied in vivo . Conventional animals contain variable and uncharacterized indigenous 7α-dehydroxylating organisms that cannot be selectively removed, making controlled colonization with a specific strain in the context of an undisturbed microbiota unfeasible. In the present study, we used a recently established, standardized gnotobiotic mouse model that is stably associated with a simplified murine 12-species "oligo-mouse microbiota" (Oligo-MM 12 ). It is representative of the major murine intestinal bacterial phyla, but is deficient for 7α-dehydroxylation. We find that the Oligo-MM 12 consortium carries out bile acid deconjugation, a prerequisite for 7α-dehydroxylation, and confers no resistance to C. difficile infection (CDI). Amendment of Oligo-MM 12 with C. scindens normalized the large intestinal bile acid composition by reconstituting 7�

Helicobacter Infection Significantly Alters Pregnancy Success in Laboratory Mice.

PubMed

Bracken, Tara C; Cooper, Caitlin A; Ali, Zil; Truong, Ha; Moore, Julie M

2017-05-01

Helicobacter spp. are gram-negative, helically shaped bacteria that cause gastric and enterohepatic infections in mammalian species. Although Helicobacter infection frequently is implicated to interfere with reproductive success, few experimental data support these claims. We therefore retrospectively investigated the effect of Helicobacter infection on murine pregnancy outcome after the identification of endemic Helicobacter infection in an animal research facility. Multiplex conventional PCR analysis was used to characterize Helicobacter infection status in one inbred and 2 transgenic strains of mice in 2 self-contained rooms assigned to the same investigator. Outcomes of timed-mating experiments were compared among Helicobacter spp.-infected and uninfected mice of the same strain; Helicobacter infection was eradicated from the colony through fostering with uninfected dams. Although Helicobacter infection affected fecundity in only one strain of transgenic mouse, the total number of embryos per gravid uterus was significantly reduced in C57BL/6J mice that were infected with a single Helicobacter species, H. typhlonius. Helicobacter infection was also associated with a significant increase in the number of resorbing embryos per uterus and significant decreases in pregnancy-associated weight gain relative to uninfected mice in C57BL6/J mice and one transgenic strain. Helicobacter spp.-infected mice of all tested strains exhibited higher frequency of intrauterine hemorrhaging relative to uninfected mice. These results indicate that naturally-acquired Helicobacter infection not only reduces the productivity of a research animal breeding colony, but also negatively impacts embryo health. Despite these deleterious effects, these data suggest that colonies can be rederived to be Helicobacter-free by Cesarean section and fostering with uninfected dams. This paper provides the first evidence that H. typhlonius infection is sufficient to interfere with reproductive success

Rearing the Fruit Fly Drosophila melanogaster Under Axenic and Gnotobiotic Conditions.

PubMed

Koyle, Melinda L; Veloz, Madeline; Judd, Alec M; Wong, Adam C-N; Newell, Peter D; Douglas, Angela E; Chaston, John M

2016-07-30

The influence of microbes on myriad animal traits and behaviors has been increasingly recognized in recent years. The fruit fly Drosophila melanogaster is a model for understanding microbial interactions with animal hosts, facilitated by approaches to rear large sample sizes of Drosophila under microorganism-free (axenic) conditions, or with defined microbial communities (gnotobiotic). This work outlines a method for collection of Drosophila embryos, hypochlorite dechorionation and sterilization, and transfer to sterile diet. Sterilized embryos are transferred to sterile diet in 50 ml centrifuge tubes, and developing larvae and adults remain free of any exogenous microbes until the vials are opened. Alternatively, flies with a defined microbiota can be reared by inoculating sterile diet and embryos with microbial species of interest. We describe the introduction of 4 bacterial species to establish a representative gnotobiotic microbiota in Drosophila. Finally, we describe approaches for confirming bacterial community composition, including testing if axenic Drosophila remain bacteria-free into adulthood.

Protein Malnutrition Modifies Innate Immunity and Gene Expression by Intestinal Epithelial Cells and Human Rotavirus Infection in Neonatal Gnotobiotic Pigs

PubMed Central

Paim, Francine C.; Kandasamy, Sukumar; Alhamo, Moyasar A.; Fischer, David D.; Langel, Stephanie N.; Deblais, Loic; Kumar, Anand; Chepngeno, Juliet; Shao, Lulu; Huang, Huang-Chi; Candelero-Rueda, Rosario A.; Rajashekara, Gireesh

2017-01-01

ABSTRACT Malnutrition affects millions of children in developing countries, compromising immunity and contributing to increased rates of death from infectious diseases. Rotavirus is a major etiological agent of childhood diarrhea in developing countries, where malnutrition is prevalent. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. In this study, we used neonatal gnotobiotic (Gn) pigs transplanted with the fecal microbiota of a healthy 2-month-old infant (HIFM) and fed protein-deficient or -sufficient bovine milk diets. Protein deficiency induced hypoproteinemia, hypoalbuminemia, hypoglycemia, stunting, and generalized edema in Gn pigs, as observed in protein-malnourished children. Irrespective of the diet, human rotavirus (HRV) infection early, at HIFM posttransplantation day 3 (PTD3), resulted in adverse health effects and higher mortality rates (45 to 75%) than later HRV infection (PTD10). Protein malnutrition exacerbated HRV infection and affected the morphology and function of the small intestinal epithelial barrier. In pigs infected with HRV at PTD10, there was a uniform decrease in the function and/or frequencies of natural killer cells, plasmacytoid dendritic cells, and CD103+ and apoptotic mononuclear cells and altered gene expression profiles of intestinal epithelial cells (chromogranin A, mucin 2, proliferating cell nuclear antigen, SRY-Box 9, and villin). Thus, we have established the first HIFM-transplanted neonatal pig model that recapitulates major aspects of protein malnutrition in children and can be used to evaluate physiologically relevant interventions. Our findings provide an explanation of why nutrient-rich diets alone may lack efficacy in malnourished children. IMPORTANCE Malnutrition and rotavirus infection, prevalent in developing countries, individually and in combination, affect the health of millions of children, compromising their immunity and increasing

Transmammary infection in BALB/c mice with chronic toxocariasis.

PubMed

de Souza Aguiar, Patricia; Furtado, Raquel Dutra; de Avila, Luciana Farias da Costa; de Lima Telmo, Paula; Martins, Lourdes Helena Rodrigues; Berne, Maria Elisabeth Aires; da Silva, Pedro Eduardo Almeida; Scaini, Carlos James

2015-04-01

Human toxocariasis is a neglected public health problem. Infection of humans generally results from the accidental ingestion of embryonated Toxocara canis eggs, but it is important to broaden knowledge about other forms of transmission. This study aimed to demonstrate the prevalence of transmammary transmission in mice with chronic toxocariasis. BALB/c mice in groups 1 (G1) and 3 (G3) were inoculated with 1200 T. canis eggs 60days before mating, whereas those of group 2 (G2) were not infected. After delivery, the G1 neonates were transferred to G2 females to be nursed, and vice versa. Thus, the mice generated by G2 females and breastfed by G1 females could be infected only during lactation. In the G3 group, offspring were not exchanged. The search for T. canis larvae in the bodies of the lactating females and their offspring was performed after weaning and at 60days old, respectively. The frequency of transmammary infection in the mice generated by G2 uninfected females and breastfed by G1 infected females was 19.8%, which was similar to that observed (19.6%) in the mice bred and fed by G3 females. The frequency of infection in the mice generated by G1 females and breastfed by G2 females was only 4.2%, which was lower than that of G1 (p=0.0064) and G3 (p=0.0062) groups. Transmammary infection by mice with chronic toxocariasis was found to be more prevalent than congenital infection. Copyright © 2014. Published by Elsevier Ireland Ltd.

Persistence of polyomavirus in mice infected as adults differs from that observed in mice infected as newborns.

PubMed Central

Berke, Z; Dalianis, T

1993-01-01

By using the polymerase chain reaction (PCR) technique, a technique more sensitive than Southern analysis, which allows detection of polyomavirus DNA only in newborn and nude adult mice, it has now been possible to monitor the persistence pattern of polyomavirus DNA after infection of normal adult CBA mice for the first time. Viral signs appeared gradually, showing variations in time course and organ distribution between mice, and reached a peak activity after 2 to 3 weeks, when they could be found in bone, heart, gonads, lymph node, and skin, but disappeared by 2 to 5 months. No virus DNA was detected in the kidneys or lungs, which is in contrast to what is observed after infection of newborn mice. This finding suggests that the persistence pattern of polyomavirus is age dependent. PMID:8389934

Sphingosine rescues aged mice from pulmonary pseudomonas infection.

PubMed

Rice, Teresa C; Pugh, Amanda M; Seitz, Aaron P; Gulbins, Erich; Nomellini, Vanessa; Caldwell, Charles C

2017-11-01

Bacterial lung infection is a leading cause of death for those 65 y or older, often requiring intensive care unit admission and mechanical ventilation, which consumes considerable health care resources. Although administration of antibiotics is the standard of care for bacterial pneumonia, its overuse has led to the emergence of multidrug resistant organisms. Therefore, alternative strategies to help minimize the effects of bacterial pneumonia in the elderly are necessary. As studies have shown that sphingosine (SPH) has inherent bacterial killing properties, our goal was to assess whether it could act as a prophylactic treatment to protect aged mice from pulmonary infection by Pseudomonas aeruginosa. Aged (51 wk) and young (8 wk) C57Bl/6 mice were used in this study. Pulmonary SPH levels were determined by histology. SPH content of microparticles was quantified using a SPH kinase assay. Pneumonia was induced by intranasally treating mice with 10 6  Colony Forming Unit (CFU) P aeruginosa. Microparticles were isolated from young mice, whereas some were further incubated with SPH. We observed that SPH levels are reduced in the bronchial epithelial cells as well as the bronchoalveolar lavage microparticles isolated from aged mice, which correlates with a susceptibility to infection. We demonstrate that SPH or microparticle treatment can protect aged mice from pulmonary P aeruginosa infection. Finally, we observed that enriching microparticles with SPH before treatment eliminated the bacterial load in P aeruginosa-infected aged mice. These data suggest that prophylactic treatment with SPH could reduce lung bacterial infections for the at-risk elderly population. Copyright © 2017 Elsevier Inc. All rights reserved.

T-cell-dependent control of acute Giardia lamblia infections in mice.

PubMed

Singer, S M; Nash, T E

2000-01-01

We have studied immune mechanisms responsible for control of acute Giardia lamblia and Giardia muris infections in adult mice. Association of chronic G. lamblia infection with hypogammaglobulinemia and experimental infections of mice with G. muris have led to the hypothesis that antibodies are required to control these infections. We directly tested this hypothesis by infecting B-cell-deficient mice with either G. lamblia or G. muris. Both wild-type mice and B-cell-deficient mice eliminated the vast majority of parasites between 1 and 2 weeks postinfection with G. lamblia. G. muris was also eliminated in both wild-type and B-cell-deficient mice. In contrast, T-cell-deficient and scid mice failed to control G. lamblia infections, as has been shown previously for G. muris. Treatment of wild-type or B-cell-deficient mice with antibodies to CD4 also prevented elimination of G. lamblia, confirming a role for T cells in controlling infections. By infecting mice deficient in either alphabeta- or gammadelta-T-cell receptor (TCR)-expressing T cells, we show that the alphabeta-TCR-expressing T cells are required to control parasites but that the gammadelta-TCR-expressing T cells are not. Finally, infections in mice deficient in production of gamma interferon or interleukin 4 (IL-4) and mice deficient in responding to IL-4 and IL-13 revealed that neither the Th1 nor the Th2 subset is absolutely required for protection from G. lamblia. We conclude that a T-cell-dependent mechanism is essential for controlling acute Giardia infections and that this mechanism is independent of antibody and B cells.

Infection of Hysterectomized Mice with Chlamydia muridarum and Chlamydia trachomatis

PubMed Central

Yang, Chunfu; Whitmire, William M.; Sturdevant, Gail L.; Bock, Kevin; Moore, Ian

2017-01-01

ABSTRACT We studied infection and immunity of hysterectomized mice infected with Chlamydia muridarum and Chlamydia trachomatis to determine if there were differences between these species in their ability to infect vaginal squamous epithelial cells in vivo independently of proximal upper genital tract tissues. We found that C. muridarum readily colonized and infected vaginal squamous epithelial cells, whereas C. trachomatis did not. Primary infection of the vaginal epithelium with C. muridarum produced infections of a duration longer than that reported for normal mice. Infection resulted in an inflammatory response in the vagina characterized by neutrophils and infiltrating submucosal plasma cells consisting primarily of T cells. Despite the delayed clearance, rechallenged C. muridarum-infected mice were highly immune. Mice vaginally infected with C. muridarum produced serum and vaginal wash antibodies and an antigen-specific gamma interferon-dominated Th1-biased T cell response. By comparison, mice vaginally infected with C. trachomatis exhibited transient low-burden infections, produced no detectable tissue inflammatory response, and failed to seroconvert. We discuss how these marked differences in the biology of vaginal infection between these otherwise genetically similar species are possibly linked to pathogen-specific virulence genes and how they may influence pathology and immunity in the upper genital tract. PMID:28461392

Local immune response to primary infection and re-infection by Clonorchis sinensis in FVB mice.

PubMed

Kim, Eun-Min; Yu, Hak Sun; Jin, Yan; Choi, Min-Ho; Bae, Young Mee; Hong, Sung-Tae

2017-08-01

Although Clonorchis sinensis lives in the bile duct, few studies have investigated the local immune response in the liver and bile duct. To investigate the local immune response to C. sinensis, we investigated the activation and recruitment of various immune cells and cytokine levels in the liver and bile duct lymph nodes (BLN) in FVB mice after primary infection and re-infection. Male 4-week-old FVB mice were divided into 6 experimental groups: uninfected controls, primary infection lasting 1week (PI 1w), primary infection lasting 4weeks (PI 4w), praziquantel treatment after PI 4w (Tx), re-infection lasting 1week after Tx (RI 1w), and re-infection lasting 4weeks after Tx (RI 4w). Recovery rates were 80.0% and 73.0% in PI 1w and PI 4w mice, respectively, but significantly decreased during re-infection to 26.6% in RI 1w and 13.3% in RI 4w. This result suggested that the mice were resistant to re-infection. In the liver, Kupffer cells were augmented 70-fold in PI 1w mice (P<0.001). Kupffer cells expressed Th2-related cytokines (IL-10 and IL-13) during primary infection. In addition, serum levels of C. sinensis-specific IgG1 and IgG2a strongly increased in RI 1w mice. Secretion of C. sinensis-specific IgE reached a plateau at 4weeks after primary infection, and remained elevated in all infected groups. In conclusion, during infection with C. sinensis, Kupffer cells likely act as antigen-presenting cells, stimulating the Th2 cytokine production system. Copyright © 2016. Published by Elsevier B.V.

Sarcocystis neurona infection in gamma interferon gene knockout (KO) mice: comparative infectivity of sporocysts in two strains of KO mice, effect of trypsin digestion on merozoite viability, and infectivity of bradyzoites to KO mice and cell culture.

PubMed

Dubey, J P; Sundar, N; Kwok, O C H; Saville, W J A

2013-09-01

The protozoan Sarcocystis neurona is the primary cause of Equine Protozoal Myeloencephalitis (EPM). EPM or EPM-like illness has been reported in horses, sea otters, and several other mammals. The gamma interferon gene knockout (KO) mouse is often used as a model to study biology and discovery of new therapies against S. neurona because it is difficult to induce clinical EPM in other hosts, including horses. In the present study, infectivity of three life cycle stages (merozoites, bradyzoites, sporozoites) to KO mice and cell culture was studied. Two strains of KO mice (C57-black, and BALB/c-derived, referred here as black or white) were inoculated orally graded doses of S. neurona sporocysts; 12 sporocysts were infective to both strains of mice and all infected mice died or became ill within 70 days post-inoculation. Although there was no difference in infectivity of sporocysts to the two strains of KO mice, the disease was more severe in black mice. S. neurona bradyzoites were not infectious to KO mice and cell culture. S. neurona merozoites survived 120 min incubation in 0.25% trypsin, indicating that trypsin digestion can be used to recover S. neurona from tissues of acutely infected animals. Published by Elsevier B.V.

Mitochondrial oxidative metabolism during respiratory infection in riboflavin deficient mice.

PubMed

Brijlal, S; Lakshmi, A V; Bamji, M S

1999-12-01

Studies in children and mice have shown that respiratory infection alters riboflavin metabolism, resulting in increased urinary loss of this vitamin. This could be due to mobilization of riboflavin from the liver to blood because liver Flavin adenine dinucleotide (FAD) levels were lowered in the mice during infection. To understand the functional implications of lowered hepatic FAD levels during respiratory infection, flavoprotein functions such as oxidative phosphorylation and beta-oxidation of the liver mitochondria were examined during infection in mice. Weanling mice were fed either riboflavin-restricted or control diet for 18 days and then injected with a sublethal dose of Klebsiella pneumoniae. During infection, the state 3 respiratory rate with palmitoyl-L-carnitine and glutamate were significantly lowered (27-29%) in the riboflavin-restricted group, whereas in the control group 10% reduction was observed with palmitoyl-L-carnitine as substrate. A 22% reduction in the respiratory control ratio with palmitoyl-L-carnitine as substrate was observed during infection in the riboflavin-restricted group. The beta-oxidation of palmitoyl-L-carnitine was significantly lowered (29%) in the riboflavin-restricted infected group. The results of the study suggest that the effects of infection on vital physiologic functions were more pronounced in the riboflavin-restricted mice than in the control mice. (c) Elsevier Science Inc. 1999.

Meticillin-resistant Staphylococcus aureus infection in diabetic mice enhanced inflammation and coagulation.

PubMed

Tsao, Shyh-Ming; Hsu, Cheng-Chin; Yin, Mei-Chin

2006-04-01

BALB/cA mice were used to study the interaction of diabetes and meticillin-resistant Staphylococcus aureus (MRSA) infection on pathogen distribution, cytokine profile and inflammatory and endothelial-injury markers, as well as coagulation and anticoagulation factors. Meticillin-susceptible S. aureus (MSSA) infection did not cause death within the experimental period. MRSA-infected nondiabetic and diabetic mice died on 19.1+/-1.4 and 10.6+/-0.7 days post-infection (p.i.), respectively. MRSA and MSSA infection in diabetic mice did not result in symptomatic bacteraemia; however, MRSA infection in diabetic mice significantly reduced glucose levels (P<0.05). Diabetic mice showed significantly higher levels of C-reactive protein, fibrinogen, fibronectin and von Willebrand factor than nondiabetic mice (P<0.05), and MRSA infection further elevated the plasma levels of these inflammatory and endothelial markers (P<0.05). Before infection, diabetic mice had significantly higher plasminogen activator inhibitor-1 (PAI-1) activity, lower antithrombin III (AT-III) and protein C activities (P<0.05), and MRSA infection significantly increased PAI-1 activity further and reduced the activity of AT-III and protein C (P<0.05). MRSA infection increased the production of three Th1 cytokines, interleukin 2 (IL-2), tumour necrosis factor alpha and gamma interferon, in diabetic mice (P<0.05); however, three Th2 cytokines, IL-4, IL-6, IL-10, were elevated at 2 and 4 days p.i., and then dropped gradually. MRSA infection in diabetic mice accelerated the inflammation process, endothelial injury and blood coagulation in diabetic mice. Therefore, the development of proper infection diagnosis and timely use of effective treatments for MRSA-infected diabetic individuals is important and necessary.

Zika virus infection damages the testes in mice.

PubMed

Govero, Jennifer; Esakky, Prabagaran; Scheaffer, Suzanne M; Fernandez, Estefania; Drury, Andrea; Platt, Derek J; Gorman, Matthew J; Richner, Justin M; Caine, Elizabeth A; Salazar, Vanessa; Moley, Kelle H; Diamond, Michael S

2016-12-15

Infection of pregnant women with Zika virus (ZIKV) can cause congenital malformations including microcephaly, which has focused global attention on this emerging pathogen. In addition to transmission by mosquitoes, ZIKV can be detected in the seminal fluid of affected males for extended periods of time and transmitted sexually. Here, using a mouse-adapted African ZIKV strain (Dakar 41519), we evaluated the consequences of infection in the male reproductive tract of mice. We observed persistence of ZIKV, but not the closely related dengue virus (DENV), in the testis and epididymis of male mice, and this was associated with tissue injury that caused diminished testosterone and inhibin B levels and oligospermia. ZIKV preferentially infected spermatogonia, primary spermatocytes and Sertoli cells in the testis, resulting in cell death and destruction of the seminiferous tubules. Less damage was caused by a contemporary Asian ZIKV strain (H/PF/2013), in part because this virus replicates less efficiently in mice. The extent to which these observations in mice translate to humans remains unclear, but longitudinal studies of sperm function and viability in ZIKV-infected humans seem warranted.

[Cell-mediated immunity in mice infected with Acanthamoeba culbertsoni].

PubMed

Kim, M J; Shin, C O; Im, K I

1990-09-01

Observations were made on the differences of cell-mediated responses in mice of three infection groups differently scheduled in their severity with pathogenic Acanthamoeba culbertsoni. Infections were done by dropping 5 microliters saline suspension containing 3 x 10(3), 1 x 10(4), or 1 x 10(5) trophozoites, respectively. Amoebae were cultured axenically in CGV medium and inoculated into the right nasal cavity of C3H/HeJ mice aging around 6-8 weeks, under the anesthesia by intraperitoneal injection of secobarbital. Delayed type hypersensitivity (DTH) responses in footpad and blastogenic responses of mouse spleen cells using (3H)-thymidine and the serum antibody titer were measured up to day 14 after infection, and natural killer cell activities were measured up to day 5 after infection. The results obtained in this study were as follows: 1. The mice infected with 3 x 10(3) trophozoites showed mortality rate of 17%, and 34% in the mice infected with 1 x 10(4) trophozoites and 65% with 1 x 10(5) trophozoites. 2. In regard to DTH responses in all experimental groups, the level increased on day 7 and declined on day 14 after infection, but their differences could not be noted between infected and control groups. 3. The blastogenic responses of splenocytes treated with amoeba lysates and lipopolysaccharides (LPS) showed no difference from the control group. The blastogenic responses of splenocytes treated with concanavalin A were declined significantly in the experimental group as compared with the control group, but the blastogenic responses of splenocytes treated with polyinosinic acid were not different from the control group. There was also no difference among three infected groups. 4. The cytotoxic activity of the natural killer cells was activated on day 1 after infection and declined to the level of control group on day 2 in all experimental groups. On day 5 after infection, the natural killer cell cytotoxicity was significantly suppressed as compared with the

Reduced spatial learning in mice infected with the nematode, Heligmosomoides polygyrus.

PubMed

Kavaliers, M; Colwell, D D

1995-06-01

Parasite modification of host behaviour influences a number of critical responses, but little is known about the effects on host spatial abilities. This study examined the effects of infection with the intestinal trichostrongylid nematode, Heligmosomoides polygyrus, on spatial water maze learning by male laboratory mice, Mus musculus. In this task individual mice had to learn the spatial location of a submerged hidden platform using extramaze visual cues. Determinations of spatial performance were made on day 19 post-infection with mice that had been administered either 50 or 200 infective larvae of H. polygyrus. The infected mice displayed over 1 day of testing (6 blocks of 4 trials) significantly poorer acquisition and retention of the water maze task than either sham-infected or control mice, with mice that had received 200 infective larvae displaying significantly poorer spatial performance than individuals receiving 50 larvae. The decrease in spatial learning occurred in the absence of either any symptoms of illness and malaise, or any evident motor, visual and motivational impairments. It is suggested that in this single host system the parasitic infection-induced decrease in spatial learning arises as a side-effect of the host's immunological and neuromodulatory responses and represents a fitness cost of response to infection.

Zika virus infection damages the testes in mice

PubMed Central

Govero, Jennifer; Esakky, Prabagaran; Scheaffer, Suzanne M.; Fernandez, Estefania; Drury, Andrea; Platt, Derek J.; Gorman, Matthew J.; Richner, Justin M.; Caine, Elizabeth A.; Salazar, Vanessa; Moley, Kelle H.; Diamond, Michael S.

2017-01-01

Zika virus (ZIKV) infection of pregnant women can cause congenital malformations including microcephaly, which has focused global attention on this emerging pathogen1. In addition to transmission by mosquitoes, ZIKV can be detected in the seminal fluid of affected males for extended periods of time and transmitted sexually2. Here, using a mouse-adapted African ZIKV strain (Dakar 41519) we evaluated the consequences of infection in the male reproductive tract of mice. We observed persistence of ZIKV, but not the closely related Dengue virus (DENV), in the testis and epididymis of male mice, and this was associated with tissue injury that caused diminished testosterone and inhibin B levels, and oligospermia. ZIKV preferentially infected spermatogonia, primary spermatocytes, and Sertoli cells in the testis, resulting in cell death and destruction of the seminiferous tubules. Less damage was observed with a contemporary Asian ZIKV strain (H/PF/2013), in part because this virus replicates less efficiently in mice. The extent to which these observations in mice translate to humans remains unclear, but longitudinal studies of sperm function and viability in ZIKV-infected humans seem warranted. PMID:27798603

Milk fermented by Lactobacillus species from Brazilian artisanal cheese protect germ-free-mice against Salmonella Typhimurium infection.

PubMed

Acurcio, L B; Sandes, S H C; Bastos, R W; Sant'anna, F M; Pedroso, S H S P; Reis, D C; Nunes, Á C; Cassali, G D; Souza, M R; Nicoli, J R

2017-08-24

Ingestion of milks fermented by Lactobacillus strains showing probiotic properties is an important tool to maintain gastrointestinal health. In this study, Lactobacillus rhamnosus D1 and Lactobacillus plantarum B7, isolated from Brazilian artisanal cheese, were used as starters for the functional fermented milks to assess their probiotic properties in a gnotobiotic animal model. Male germ-free Swiss mice received a single oral dose of milk fermented by each sample, and were challenged with Salmonella Typhimurium five days afterwards. Milk fermented by both Lactobacillus strains maintained counts above 10 8 cfu/ml during cold storage. Lactobacillus strains colonised the gut of the germ-free-mice, maintaining their antagonistic effect. This colonisation led to a protective effect against Salmonella challenge, as demonstrated by reduced pathogen translocation and histological lesions, when compared to control group, especially for Lactobacillus rhamnosus D1. Additionally, mRNA expression of inflammatory (interferon gamma, interleukin (IL)-6, tumour necrosis factor alpha) and anti-inflammatory (transforming growth factor β1) cytokines was augmented in animals previously colonised and then challenged, when compared to other experimental groups. Lactobacillus plantarum B7 colonisation also promoted higher expression of IL-17, showing a proper maturation of colonised germ-free-mice immune system. IL-5 was stimulated by both strains' colonisation and not by S. Typhimurium challenge.

Innate resistance of mice to experimental infection with Naegleria fowleri.

PubMed Central

Haggerty, R M; John, D T

1978-01-01

The mouse system provides an excellent model for studying host resistance to Naegleria fowleri, the agent of primary amoebic meningoencephalitis. Innate resistance to infection with N. fowleri was examined with respect to infecting dose and the age, sex, and strain of mice. Intravenous inoculation with 10(7) amoebae per mouse produced 100% mortality in 9 days, whereas inoculation with fewer amoebae reduced the cumulative mortality. Male and female DUB/ICR mice of varying ages were inoculated intravenously with 2.5 X 10(5) N. fowleri per g of body weight. The youngest mice died first, with 100% mortality for both males and females, and mortality decreased with increasing age. Female mice were significantly more resistant to infection than males. Five strains of mice weighing approximately 20 g were inoculated intravenously with weight-adjusted doses; mortality ranged from 10% in C57BL/6 mice to 95% in A/HeCr mice. PMID:669800

Noninvasive monitoring of salmonella infections in young mice

NASA Astrophysics Data System (ADS)

Olomu, Isoken N.; Reilly-Contag, Pamela; Stevenson, David K.; Contag, Christopher H.

1999-07-01

A recently developed bioluminescent assay was used to study the influence of age and inoculum size on the acute susceptibility of newborn and juvenile BALB/c mice to Salmonella gastrointestinal infection. Three strains of Salmonella were tagged by expression of the lux operon from Photohabdus luminescenes. Using a range of inoculum sizes varied over 6 orders of magnitude, mice aged 0-6 weeks were infected by oral inoculation. LIght emitted from the tagged bacteria and transmitted through mouse tissues was used to noninvasively monitor disease progression over 7 days. In neonatal mice there was evidence of gastrointestinal infection at 24 hours even with small inocular, and at 4-7 days, the patterns of photon emission and remained and healthy throughout the study period. Inoculation of neonates with tagged LB5000 and BJ66 resulted in severe gastrointestinal infections with low and intermediate sizes of inocula respectively. These strains are known to be of reduced virulence in adult mice. These age-related differences in susceptibility emphasize the need to define virulence in the context of age of the host, and implicate maturation of innate resistance factors in determining disease patterns. Identifying these host-factors and further defining the bacterial determinants of virulence in the neonatal host will be facilitated by this noninvasive study of infection using bioluminenscent methods.

Immunity to Trichinella spiralis infection in vitamin A-deficient mice

PubMed Central

1992-01-01

Vitamin A-deficient (A-) mice make strikingly poor IgG responses when they are immunized with purified protein antigens. Previously, we showed that A- T cells overproduce interferon gamma (IFN-gamma), which then could inhibit interleukin 4 (IL-4)-stimulated B cell IgG responses. To determine if the altered IFN-gamma regulation pattern and its immunological consequences would extend to a natural infection, we studied mice infected with the parasitic helminth Trichinella spiralis. The course of the infection was similar in A- and A-sufficient (A+) mice. These mice did not differ with respect to newborn larvae/female/hour produced in the intestine, or muscle larvae burden 5 wk postinfection. They also did not differ in the intestinal worm expulsion rate until day 15, when A- mice still harbored parasites, whereas A+ mice had cleared intestinal worms. Vitamin A deficiency reduced both the frequency of B lymphocytes secreting IgG1 antibodies to parasite antigens, and the bone marrow eosinophilia associated with helminth infection. The cytokine secretion patterns in infected mice were consistent with these observations and with previous studies. Mesenteric lymph node cells from infected A- mice secreted significantly more IFN-gamma, and significantly less IL-2, IL-4, and IL- 5 than infected A+ controls. A- splenocytes secreted significantly more IFN-gamma, and equivalent amounts of IL-2, IL-4, and IL-5 compared with A+ controls. Interestingly, CD4-CD8- cells secreted the majority of the IL-4 produced in the spleen. The IL-2, IL-4, and IL-5 steady-state transcript levels correlated with secreted protein levels, but IFN- gamma transcripts did not. Although they secreted more protein, A- cells contained fewer IFN-gamma transcripts than A+ cells. These results suggest two vitamin A-mediated regulation steps in IFN-gamma gene expression: positive regulation of IFN-gamma transcript levels, and negative regulation posttranscriptionally. The essentially unaltered outcome of T

Hepatitis virus infection affects DNA methylation in mice with humanized livers.

PubMed

Okamoto, Yasuyuki; Shinjo, Keiko; Shimizu, Yasuhiro; Sano, Tsuyoshi; Yamao, Kenji; Gao, Wentao; Fujii, Makiko; Osada, Hirotaka; Sekido, Yoshitaka; Murakami, Shuko; Tanaka, Yasuhito; Joh, Takashi; Sato, Shinya; Takahashi, Satoru; Wakita, Takaji; Zhu, Jingde; Issa, Jean-Pierre J; Kondo, Yutaka

2014-02-01

Cells of tumors associated with chronic inflammation frequently have altered patterns of DNA methylation, including hepatocellular carcinomas. Chronic hepatitis has also been associated with aberrant DNA methylation, but little is known about their relationship. Pyrosequencing was used to determine the methylation status of cultured Huh7.5.1 hepatoma cells after hepatitis C virus (HCV) infection. We also studied mice with severe combined immunodeficiency carrying the urokinase-type plasminogen activator transgene controlled by an albumin promoter (urokinase-type plasminogen activator/severe combined immunodeficient mice), in which up to 85% of hepatocytes were replaced by human hepatocytes (chimeric mice). Mice were given intravenous injections of hepatitis B virus (HBV) or HCV, liver tissues were collected, and DNA methylation profiles were determined at different time points after infection. We also compared methylation patterns between paired samples of hepatocellular carcinomas and adjacent nontumor liver tissues from patients. No reproducible changes in DNA methylation were observed after infection of Huh7.5.1 cells with HCV. Livers from HBV- and HCV-infected mice had genome-wide, time-dependent changes in DNA methylation, compared with uninfected urokinase-type plasminogen activator/severe combined immunodeficient mice. There were changes in 160 ± 63 genes in HBV-infected and 237 ± 110 genes in HCV-infected mice. Methylation of 149 common genes increased in HBV- and HCV-infected mice; methylation of some of these genes also increased in hepatocellular carcinoma samples from patients compared with nontumor tissues. Expression of Ifng, which is expressed by natural killer cells, increased significantly in chimeric livers, in concordance with induction of DNA methylation, after infection with HBV or HCV. Induction of Ifng was reduced after administration of an inhibitor of natural killer cell function (anti-asialo GM1). In chimeric mice with humanized livers

TAM Receptors Are Not Required for Zika Virus Infection in Mice.

PubMed

Hastings, Andrew K; Yockey, Laura J; Jagger, Brett W; Hwang, Jesse; Uraki, Ryuta; Gaitsch, Hallie F; Parnell, Lindsay A; Cao, Bin; Mysorekar, Indira U; Rothlin, Carla V; Fikrig, Erol; Diamond, Michael S; Iwasaki, Akiko

2017-04-18

Tyro3, Axl, and Mertk (TAM) receptors are candidate entry receptors for infection with the Zika virus (ZIKV), an emerging flavivirus of global public health concern. To investigate the requirement of TAM receptors for ZIKV infection, we used several routes of viral inoculation and compared viral replication in wild-type versus Axl -/- , Mertk -/- , Axl -/- Mertk -/- , and Axl -/- Tyro3 -/- mice in various organs. Pregnant and non-pregnant mice treated with interferon-α-receptor (IFNAR)-blocking (MAR1-5A3) antibody and infected subcutaneously with ZIKV showed no reliance on TAMs for infection. In the absence of IFNAR-blocking antibody, adult female mice challenged intravaginally with ZIKV showed no difference in mucosal viral titers. Similarly, in young mice that were infected with ZIKV intracranially or intraperitoneally, ZIKV replication occurred in the absence of TAM receptors, and no differences in cell tropism were observed. These findings indicate that, in mice, TAM receptors are not required for ZIKV entry and infection. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Coping with parvovirus infections in mice: health surveillance and control.

PubMed

Janus, Lydia M; Bleich, Andre

2012-01-01

Parvoviruses of mice, minute virus of mice (MVM) and mouse parvovirus (MPV), are challenging pathogens to eradicate from laboratory animal facilities. Due to the impediment on rodent-based research, recent studies have focused on the assessment of re-derivation techniques and parvoviral potential to induce persistent infections. Summarizing recent data, this review gives an overview on studies associated with parvoviral impact on research, diagnostic methods, parvoviral persistence and re-derivation techniques, demonstrating the complex nature of parvovirus infection in mice and unfolding the challenge of controlling parvovirus infections in laboratory animal facilities.

Administration of kefir-fermented milk protects mice against Giardia intestinalis infection.

PubMed

Franco, Mariana Correa; Golowczyc, Marina A; De Antoni, Graciela L; Pérez, Pablo F; Humen, Martín; Serradell, María de los Angeles

2013-12-01

Giardiasis, caused by the protozoan Giardia intestinalis, is one of the most common intestinal diseases worldwide and constitutes an important problem for the public health systems of various countries. Kefir is a probiotic drink obtained by fermenting milk with 'kefir grains', which consist mainly of bacteria and yeasts that coexist in a complex symbiotic association. In this work, we studied the ability of kefir to protect mice from G. intestinalis infection, and characterized the host immune response to this probiotic in the context of the intestinal infection. Six- to 8-week-old C75BL/6 mice were separated into four groups: controls, kefir mice (receiving 1 : 100 dilution of kefir in drinking water for 14 days), Giardia mice (infected orally with 4×10(7) trophozoites of G. intestinalis at day 7) and Giardia-kefir mice (kefir-treated G. intestinalis-infected mice), and killed at 2 or 7 days post-infection. Kefir administration was able to significantly reduce the intensity of Giardia infection at 7 days post-infection. An increase in the percentage of CD4(+) T cells at 2 days post-infection was observed in the Peyer's patches (PP) of mice belonging to the Giardia group compared with the control and kefir groups, while the percentage of CD4(+) T cells in PP in the Giardia-kefir group was similar to that of controls. At 2 days post-infection, a reduction in the percentage of B220-positive major histocompatibility complex class II medium cells in PP was observed in infected mice compared with the other groups. At 7 days post-infection, Giardia-infected mice showed a reduction in RcFcε-positive cells compared with the control group, suggesting a downregulation of the inflammatory response. However, the percentages of RcFcε-positive cells did not differ from controls in the kefir and Giardia-kefir groups. An increase in IgA-positive cells was observed in the lamina propria of the kefir group compared with controls at 2 days post-infection. Interestingly, the

Balb/Cj male mice do not feminize after infection with larval Taenia crassiceps.

PubMed

Aldridge, Jerry R; Jennette, Mary A; Kuhn, R E

2007-02-01

Balb/cJ mice fail to mount an immune response capable of clearing infection with larval Taenia crassiceps. Additionally, male Balb/cJ mice display a lag in larval growth of approximately 3 wk as compared to growth in female mice. It has been reported that male Balb/ cAnN mice generate a protective immune response early in infection, and become permissive to larval growth after they feminize (200-fold increase in serum estradiol and 90% decrease in serum testosterone). To determine if a different strain of Balb/c mice (Balb/cJ) also feminize, serum was collected from infected male mice for 16 wk and levels of 17-beta-estradiol and testosterone were measured via ELISA. In addition, the mounting responses of 12- and 16-wk infected male mice, as well as uninfected control mice, were determined after isolation with a female mouse. The results of these experiments show that male Balb/cJ mice do not feminize during infection with larval T. crassiceps. There was no significant change in serum levels of either 17-beta-estradiol or testosterone during the course of infection (> 16 wk). Moreover, there was no significant decrease in the number of times infected male mice mounted the female mouse as compared to uninfected controls. These results suggest that there may be variances between the substrains of Balb/c mice that lead to the phenotypic differences reported for male Balb/cJ and Balb/cAnN mice.

Pulmonary infection of cystic fibrosis mice with Staphylococcus aureus requires expression of α-toxin.

PubMed

Keitsch, Simone; Riethmüller, Joachim; Soddemann, Matthias; Sehl, Carolin; Wilker, Barbara; Edwards, Michael J; Caldwell, Charles C; Fraunholz, Martin; Gulbins, Erich; Becker, Katrin Anne

2018-05-01

Pulmonary infections of cystic fibrosis (CF) patients with Staphylococcus aureus (S. aureus) occur very early in the disease. The molecular details that cause infection-susceptibility of CF patients to and mediate infection with S. aureus are poorly characterized. Therefore, we aimed to identify the role of α-toxin, a major S. aureus toxin, for pulmonary infection of CF mice. Infection with S. aureus JE2 resulted in severe pneumonia in CF mice, while wildtype mice were almost unaffected. Deficiency of α-toxin in JE2-Δhla reduced the pathogenicity of S. aureus in CF mice. However, CF mice were still more susceptible to the mutant S. aureus strain than wildtype mice. The S. aureus JE2 induced a marked increase of ceramide and a downregulation of sphingosine and acid ceramidase expression in bronchi of CF mice. Deletion of α-toxin reduced these changes after infection of CF mice. Similar changes were observed in wildtype mice, but at much lower levels. Our data indicate that expression of α-toxin is a major factor causing S. aureus infections in CF mice. Wildtype S. aureus induces a marked increase of ceramide and a reduction of sphingosine and acid ceramidase expression in bronchial epithelial cells of wildtype and CF mice, changes that determine infection susceptibility.

THE INFECTION OF MICE WITH SWINE INFLUENZA VIRUS.

PubMed

Shope, R E

1935-09-30

The experiments confirm the earlier observation of Andrewes, Laidlaw and Smith that the swine influenza virus is pathogenic for white mice when administered intranasally. Two field strains of the swine influenza virus were found to differ in their initial pathogenicity for mice. One strain was apparently fully pathogenic even in its 1st mouse passage while the other required 2 or 3 mouse passages to acquire full virulence for this species. Both strains, however, were initially infectious for mice, without the necessity of intervening ferret passages. There is no evidence that bacteria play any significant rôle in the mouse disease though essential in that of swine, and fatal pneumonias can be produced in mice by pure virus infections. Mice surviving the virus disease are immune to reinfection for at least a month. In mice the disease is not contagious though it is notably so in swine. The virus, while regularly producing fatal pneumonias when administered intranasally to mice, appears to be completely innocuous when given subcutaneously or intraperitoneally. Prolonged serial passage of the virus in mice does not influence its infectivity or virulence for swine or ferrets. It is a stable virus so far as its infectivity is concerned, and can be transferred at will from any one of its three known susceptible hosts to any other. In discussing these facts the stability of the swine influenza virus has been contrasted with the apparent instability of freshly isolated strains of the human influenza virus. Though the mouse is an un-natural host for the virus it is, nevertheless, useful for the study of those aspects of swine influenza which have to do with the virus only.

Antibody hyporesponsiveness in resistant BALB/cJ mice intracorneally infected with Pseudomonas aeruginosa.

PubMed

Berk, R S; Preston, M; Montgomery, I N; Hazlett, L D; Tse, H Y

Six- to eight-week-old BALB/cJ (and BALB/cPi) mice were found able to restore corneal clarity within 3 to 4 weeks after intracorneal infection with Pseudomonas aeruginosa strain 19660. However, enzyme-linked immunosorbent assay (ELISA) for serum immunoglobulins directed specifically against P. aeruginosa indicated that the mice were initially non- or hypo-responsive for IgG and IgA over the 4-week holding period. Low IgM titers could be detected 1 week after infection, but tended to decrease with time. When the mice were re-infected by using the contralateral control eye, then the serum IgG levels began to gradually increase as the time interval following the secondary infection increased from 1 to 3 weeks. Re-infected mice did not show a significantly increased rate of corneal clarity restoration with time, when compared to the corneas of mice receiving only a primary infection despite the presence of serum antibodies specific to P. aeruginosa. When congenic mice of the BALB/c background carrying the DBA/2N Idh/Pep-3 locus found on chromosome 1 were intracorneally infected, they tended to restore corneal clarity at approximately the same rate as the BALB/cJ mice. However, the congenic mice mounted a faster and substantially greater magnitude of serum IgM and IgG response during the primary infection than BALB/cJ mice receiving either a primary and/or secondary infection. IgG subclass studies with the congenic mice indicated that serum IgG1, and IgG2a to a lesser extent, were the primary immunoglobulins produced and no major shift in subclass was noted with time during the primary infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Perfluorocarbon emulsion therapy attenuates pneumococcal infection in sickle cell mice.

PubMed

Helmi, Nawal; Andrew, Peter W; Pandya, Hitesh C

2015-05-15

Impaired immunity and tissue hypoxia-ischemia are strongly linked with Streptococcus pneumoniae pathogenesis in patients with sickle cell anemia. Perfluorocarbon emulsions (PFCEs) have high O2-dissolving capacity and can alleviate tissue hypoxia. Here, we evaluate the effects of intravenous PFCE therapy in transgenic sickle cell (HbSS) mice infected with S. pneumoniae. HbSS and C57BL/6 (control) mice intravenously infected with S. pneumoniae were treated intravenously with PFCE or phosphate-buffered saline (PBS) and then managed in either air/O2 (FiO2 proportion, 50%; hereafter referred to as the PFCE-O2 and PBS-O2 groups) or air only (hereafter, the PFCE-air and PBS-air groups) gas mixtures. Lungs were processed for leukocyte and bacterial counts and cytokine measurements. HbSS mice developed severe pneumococcal infection significantly faster than C57BL/6 mice (Kaplan-Maier analysis, P < .05). PFCE-O2-treated HbSS mice had significantly better survival at 72 hours than HBSS mice treated with PFCE-air, PBS-O2, or PBS-air (P < .05). PFCE-O2-treated HbSS mice also had significantly lower pulmonary leukocyte counts, lower interleukin 1β and interferon γ levels, and higher interleukin 10 levels than PFCE-air-treated HbSS mice. Clearance of S. pneumoniae from lungs of HbSS mice or C57BL/6 mice was not altered by PFCE treatment. Improved survival of PFCE-O₂-treated HbSS mice infected with S. pneumoniae is associated with altered pulmonary inflammation but not enhanced bacterial clearance. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Targeted photodynamic therapy for infected wounds in mice

NASA Astrophysics Data System (ADS)

Hamblin, Michael R.; O'Donnell, David A.; Zahra, Touqir; Contag, Christopher H.; McManus, Albert T.; Hasan, Tayyaba

2002-06-01

Although many workers have used photodynamic therapy to kill bacteria in vitro, the use of this approach has seldom been reported in vivo in animal models of infection. We report on the use of a targeted polycationic photosensitizer conjugate between poly-L-lysine and chlorin(e6) that can penetrate the Gram (-) outer membrane together with red laser light to kill Escherichia coli and Pseudomonas aeruginosa infecting excisional wounds in mice. We used genetically engineered luminescent bacteria that allowed the infection to be imaged in mouse wounds using a sensitive CCD camera. Wounds were infected with 5x106 bacteria, followed by application of the conjugate in solution and illumination. There was a light-dose dependent loss of luminescence as measured by image analysis in the wound treated with conjugate and light, not seen in control wounds. This strain of E coli is non-invasive and the infection in untreated wounds spontaneously resolved in a few days and all wounds healed equally well showing the photodynamic treatment did not damage the host tissue. P aeruginosa is highly invasive and mice with untreated or control wounds all died while 90% of PDT treated mice survived. PDT may have a role to play in the rapid treatment of infected wounds in view of the worldwide rise in antibiotic resistance.

Helicobacter sp. MIT 01-6451 infection during fetal and neonatal life in laboratory mice.

PubMed

Yamanaka, Hitoki; Nakanishi, Tai; Takagi, Toshikazu; Ohsawa, Makiko; Kubo, Noriaki; Yamamoto, Naoto; Takemoto, Takahira; Ohsawa, Kazutaka

2015-01-01

Helicobacter sp. MIT 01-6451 has been detected in SPF mice kept in Japan. To characterize strain MIT 01-6451, its infection route during fetal and neonatal life and effects on pregnancy were investigated using immunocompetent and immunodeficient mouse strains (BALB/c, C57BL/6, and SCID). MIT 01-6451 was detected in the uterus, vagina, and mammary glands of 50% of infected SCID mice, whereas these tissues were all negative in immunocompetent mice. No fetal infections with MIT 01-6451 were detected at 16-18 days after pregnancy in any mouse strain. In newborn mice, MIT 01-6451 was detected in intestinal tissue of C57BL/6 and SCID mice at 9-11 days after birth, but not in BALB/c mice. The IgA and IgG titers to MIT 01-6451 in sera of C57BL/6 female mice were significantly lower than those of BALB/c mice. Although no significant differences in the number of newborns per litter were observed between MIT 01-6451-infected and MIT 01-6451-free dams, the birth rate was lower in infected SCID mice than in control SCID mice. The present results indicated that MIT 01-6451 infects newborn mice after birth rather than by vertical transmission to the fetus via the placenta and that MIT 01-6451 infection shows opportunistically negative effects on the birth rate. In addition, the maternal immune response may affect infection of newborn mice with MIT 01-6451 through breast milk.

Helicobacter sp. MIT 01-6451 infection during fetal and neonatal life in laboratory mice

PubMed Central

Yamanaka, Hitoki; Nakanishi, Tai; Takagi, Toshikazu; Ohsawa, Makiko; Kubo, Noriaki; Yamamoto, Naoto; Takemoto, Takahira; Ohsawa, Kazutaka

2015-01-01

Helicobacter sp. MIT 01-6451 has been detected in SPF mice kept in Japan. To characterize strain MIT 01-6451, its infection route during fetal and neonatal life and effects on pregnancy were investigated using immunocompetent and immunodeficient mouse strains (BALB/c, C57BL/6, and SCID). MIT 01-6451 was detected in the uterus, vagina, and mammary glands of 50% of infected SCID mice, whereas these tissues were all negative in immunocompetent mice. No fetal infections with MIT 01-6451 were detected at 16–18 days after pregnancy in any mouse strain. In newborn mice, MIT 01-6451 was detected in intestinal tissue of C57BL/6 and SCID mice at 9–11 days after birth, but not in BALB/c mice. The IgA and IgG titers to MIT 01-6451 in sera of C57BL/6 female mice were significantly lower than those of BALB/c mice. Although no significant differences in the number of newborns per litter were observed between MIT 01-6451-infected and MIT 01-6451-free dams, the birth rate was lower in infected SCID mice than in control SCID mice. The present results indicated that MIT 01-6451 infects newborn mice after birth rather than by vertical transmission to the fetus via the placenta and that MIT 01-6451 infection shows opportunistically negative effects on the birth rate. In addition, the maternal immune response may affect infection of newborn mice with MIT 01-6451 through breast milk. PMID:26134357

Arthritis is developed in Borrelia-primed and -infected mice deficient of interleukin-17.

PubMed

Kuo, Joseph; Warner, Thomas F; Munson, Erik L; Nardelli, Dean T; Schell, Ronald F

2016-10-01

Interleukin-17 (IL-17) has been shown to participate in the development of Lyme arthritis in experimental mice. For example, neutralization of IL-17 with antibodies inhibits induction of arthritis in Borrelia-primed and -infected C57BL/6 wild-type mice. We hypothesized that mice lacking IL-17 would fail to develop Borrelia-induced arthritis. IL-17-deficient and wild-type C57BL/6 mice were primed with heat-inactivated Borrelia and then infected with viable spirochetes 3 weeks later. No swelling or major histopathological changes of the hind paws were detected in IL-17-deficient or wild-type mice that were primed with Borrelia or infected with viable spirochetes. By contrast, IL-17-deficient and wild-type mice that were primed and subsequently infected with heterologous Borrelia developed severe swelling and histopathological changes of the hind paws. In addition, Borrelia-primed and -infected IL-17-deficient mice exhibited elevated gamma-interferon (IFN-γ) levels in sera and increased frequencies of IFN-γ-expressing lymphocytes in popliteal lymph nodes compared to Borrelia-primed and -infected wild-type mice. These results demonstrate that IL-17 is not required for development of severe pathology in response to infection with Borrelia burgdorferi, but may contribute to disease through an interaction with IFN-γ. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Gastric Helicobacter Infection Inhibits Development of Oral Tolerance to Food Antigens in Mice

PubMed Central

Matysiak-Budnik, Tamara; van Niel, Guillaume; Mégraud, Francis; Mayo, Kathryn; Bevilacqua, Claudia; Gaboriau-Routhiau, Valérie; Moreau, Marie-Christiane; Heyman, Martine

2003-01-01

The increase in the transcellular passage of intact antigens across the digestive epithelium infected with Helicobacter pylori may interfere with the regulation of mucosal immune responses. The aim of this work was to study the capacity of Helicobacter infection to inhibit the development of oral tolerance or to promote allergic sensitization and the capacity of a gastro-protective agent, rebamipide, to interfere with these processes in mice. Oral tolerance to ovalbumin (OVA) was studied in 48 C3H/He 4-week-old mice divided into four groups: (i) OVA-sensitized mice; (ii) OVA-“tolerized” mice (that is, mice that were rendered immunologically tolerant); (iii) H. felis-infected, OVA-tolerized mice; (iv) and H. felis-infected, OVA-tolerized, rebamipide-treated mice. Oral sensitization to hen egg lysozyme (HEL) was studied in 48 mice divided into four groups: (i) controls; (ii) HEL-sensitized mice; (iii) H. felis-infected, HEL-sensitized mice; and (iv) H. felis-infected, HEL-sensitized, rebamipide-treated mice. Specific anti-OVA or anti-HEL immunoglobulin E (IgE) and IgG1/IgG2a serum titers were measured by enzyme-linked immunosorbent assay. Additionally, the capacity of rebamipide to interfere with antigen presentation and T-cell activation in vitro, as well as absorption of rebamipide across the epithelial monolayer, was tested. H. felis infection led to the inhibition of oral tolerance to OVA, but rebamipide prevented this inhibitive effect of H. felis. H. felis infection did not enhance the sensitization to HEL, but rebamipide inhibited the development of this sensitization. Moreover, rebamipide inhibited in a dose-dependent manner antigen presentation and T-cell activation in vitro and was shown to be able to cross the epithelium at a concentration capable of inducing this inhibitory effect. We conclude that H. felis can inhibit the development of oral tolerance to OVA in mice and that this inhibition is prevented by rebamipide. PMID:12933867

Helicobacter pylori infection aggravates diet-induced nonalcoholic fatty liver in mice.

PubMed

He, Cong; Cheng, Dandan; Wang, Huan; Wu, Ketao; Zhu, Yin; Lu, Nonghua

2018-04-12

Previous epidemiological studies have suggested a link between Helicobacter pylori (H. pylori) infection and nonalcoholic fatty liver disease (NAFLD), yet animal studies are lacking to elucidate this association. In this study, we evaluated the potential effects of H. pylori infection on NAFLD in mice. We first established two strains of H. pylori infected mice model with either chow diet or high fat diet (HFD). The body and liver weight, blood glucose, serum transaminases and lipid levels and markers of hepatic inflammation were measured. Histological analyses were also performed on liver tissue. Expressions of fat synthesis genes as well as insulin signaling proteins were also determined. After 24 weeks of treatment, the abdominal circumference, fasting blood glucose, low-density cholesterol and alanine transaminase were significantly increased in HFD feeding mice infected with H. pylori SS1 compared to HFD controls. Moreover, HFD fed mice infected with H. pylori SS1 showed significantly more liver steatosis. H. pylori SS1 infection inhibited phosphorylation of IRS1 and Akt and trended to increase the expression of IL-1β and TNF-α in the liver. H. pylori infection is associated with NAFLD in C57BL/6 mice which depends on the bacterial strain and diet structure. The infection of H. pylori SS1 instead of NCTC11637 in combination with HFD induced more severe liver steatosis. H. pylori infection may play a role in NAFLD development and further studies are needed to determine whether H. pylori eradication can improve NAFLD risk. Copyright © 2018. Published by Elsevier Masson SAS.

Immunosuppressive CD71+ erythroid cells compromise neonatal host defence against infection

NASA Astrophysics Data System (ADS)

Elahi, Shokrollah; Ertelt, James M.; Kinder, Jeremy M.; Jiang, Tony T.; Zhang, Xuzhe; Xin, Lijun; Chaturvedi, Vandana; Strong, Beverly S.; Qualls, Joseph E.; Steinbrecher, Kris A.; Kalfa, Theodosia A.; Shaaban, Aimen F.; Way, Sing Sing

2013-12-01

Newborn infants are highly susceptible to infection. This defect in host defence has generally been ascribed to the immaturity of neonatal immune cells; however, the degree of hyporesponsiveness is highly variable and depends on the stimulation conditions. These discordant responses illustrate the need for a more unified explanation for why immunity is compromised in neonates. Here we show that physiologically enriched CD71+ erythroid cells in neonatal mice and human cord blood have distinctive immunosuppressive properties. The production of innate immune protective cytokines by adult cells is diminished after transfer to neonatal mice or after co-culture with neonatal splenocytes. Neonatal CD71+ cells express the enzyme arginase-2, and arginase activity is essential for the immunosuppressive properties of these cells because molecular inhibition of this enzyme or supplementation with L-arginine overrides immunosuppression. In addition, the ablation of CD71+ cells in neonatal mice, or the decline in number of these cells as postnatal development progresses parallels the loss of suppression, and restored resistance to the perinatal pathogens Listeria monocytogenes and Escherichia coli. However, CD71+ cell-mediated susceptibility to infection is counterbalanced by CD71+ cell-mediated protection against aberrant immune cell activation in the intestine, where colonization with commensal microorganisms occurs swiftly after parturition. Conversely, circumventing such colonization by using antimicrobials or gnotobiotic germ-free mice overrides these protective benefits. Thus, CD71+ cells quench the excessive inflammation induced by abrupt colonization with commensal microorganisms after parturition. This finding challenges the idea that the susceptibility of neonates to infection reflects immune-cell-intrinsic defects and instead highlights processes that are developmentally more essential and inadvertently mitigate innate immune protection. We anticipate that these

Cell phenotypic change due to Cryptosporidium parvum infection in immunocompetent mice.

PubMed

Codices, Vera; Martins, Catarina; Novo, Carlos; Pinho, Mário; de Sousa, Bruno; Lopes, Angela; Borrego, Miguel; Matos, Olga

2013-03-01

Cryptosporidium parvum is an intracellular parasite causing enteritis which can become life-threatening in immunocompromised host. Immunoregulatory T cells play a central role in the regulatory network of the host. Here, we proposed to characterize the populations of immune cells during infection and reinfection with C. parvum. Four-week-old BALB/C mice were inoculated with oocysts of C. parvum at days 0 and 22. Fecal and blood samples, spleens, and small intestines were collected for analysis. Peripheral blood and spleen cell populations were characterized by flow cytometry. After infection (days 0 to 21), mice presented higher values of neutrophils, eosinophils, NK cells and CD4(+)CD25(high) T cells in peripheral blood. After reinfection, this upward trend continued in the following days for all four populations in infected mice. At day 35, infected mice presented similar values to the control group, except for CD4(+)CD25(high) T cells, which remained higher in infected mice. A possible correlation between alterations in blood and spleen cell populations was also studied, but no consistent association could be established. Small intestine sections were screened for intracellular stages of the parasite but no evidence of pathology was observed. Here, we report information which may be important for the understanding of the specific cell-mediated response in immunocompetent mice to C. parvum infection. Although some questions remain unanswered and complementary studies are needed, our results are expected to contribute to a better understanding of innate and Treg cells role in the clearance process of this parasite.

Interleukin-13 is involved in the formation of liver fibrosis in Clonorchis sinensis-infected mice.

PubMed

Xu, Yanquan; Liang, Pei; Bian, Meng; Chen, Wenjun; Wang, Xiaoyun; Lin, Jinsi; Shang, Mei; Qu, Hongling; Wu, Zhongdao; Huang, Yan; Yu, Xinbing

2016-07-01

Clonorchiasis is a chronic infection disease often accompanied by formation of liver fibrosis. Previous study has identified that Clonorchis sinensis (C. sinensis, Cs) infection and CsRNASET2 (a member of CsESPs) immunization can drive Th2 immune response. IL-13, a multifunctional Th2 cytokine, has been widely confirmed to be profibrotic mediator. We want to determine whether IL-13 is involved in the generation of liver fibrosis during C. sinensis infection. A part of mice were infected with C. sinensis or immunized with CsRNASET2, respectively. Another part of mice were intravenously injected with rIL-13. Liver tissues of C. sinensis-infected mice were stained with hematoxylin-eosin and Masson's trichrome, respectively. The transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1 in the livers of infected mice and rIL-13-treated mice were measured by quantitative RT-PCR. Besides, splenocytes of C. sinensis-infected and CsRNASET2-immunized mice were isolated, respectively. The levels of IL-13 in splenocytes were detected by ELISA. Our results displayed that the livers of C. sinensis-infected mice had serious chronic inflammation and collagen deposition. The transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1 in the livers of C. sinensis-infected mice were obviously increased. Splenocytes from both C. sinensis-infected and CsRNASET2-immunized mice expressed high levels of IL-13. Moreover, rIL-13 treatment markedly promoted the transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1. These data implied that hepatic fibrosis was formed in the livers of C. sinensis-infected mice, and IL-13 induced by C. sinensis infection and CsRNASET2 immunization might favor this progression.

Dietary lactosucrose suppresses influenza A (H1N1) virus infection in mice

PubMed Central

KISHINO, Eriko; TAKEMURA, Naho; MASAKI, Hisaharu; ITO, Tetsuya; NAKAZAWA, Masatoshi

2015-01-01

This study examined the effects of lactosucrose (4G-β-D-galactosylsucrose) on influenza A virus infections in mice. First, the effects of lactosucrose on fermentation in the cecum and on immune function were investigated. In female BALB/c mice, lactosucrose supplementation for 6 weeks promoted cecal fermentation and increased both secretory IgA (SIgA) levels in feces and total IgA and IgG2a concentrations in serum. Both the percentage of CD4+ T cells in Peyer’s patches and the cytotoxic activity of splenic natural killer (NK) cells increased significantly in response to lactosucrose. Next, we examined the effects of lactosucrose on low-dose influenza A virus infection in mice. After 2 weeks of dietary supplementation with lactosucrose, the mice were infected with low-dose influenza A virus. At 7 days post infection, a comparison with control mice showed that weight loss was suppressed, as were viral titers in the lungs. In the spleens of lactosucrose-fed mice, there was an increase in the percentage of NK cells. Lastly, mice fed lactosucrose were challenged with a lethal dose of influenza A virus. The survival rate of these mice was significantly higher than that of mice fed a control diet. These results suggested that lactosucrose supplementation suppresses influenza A virus infection by augmenting innate immune responses and enhancing cellular and mucosal immunity. PMID:26594606

A New Animal Model of Gastric Lymphomagenesis: APRIL Transgenic Mice Infected by Helicobacter Species.

PubMed

Floch, Pauline; Izotte, Julien; Guillemaud, Julien; Sifré, Elodie; Costet, Pierre; Rousseau, Benoit; Laur, Amandine Marine; Giese, Alban; Korolik, Victoria; Mégraud, Francis; Dubus, Pierre; Hahne, Michael; Lehours, Philippe

2017-07-01

APRIL is a member of the tumor necrosis factor cytokine family involved in the regulation of B-cell immunity. We present a study of the infection by Helicobacter species of transgenic (Tg) C57BL6 mice, ectopically expressing the human form of APRIL. Wild-type (WT) and APRIL Tg mice were infected with Helicobacter felis and Helicobacter pylori and compared with noninfected animals. Mice were euthanized 18 months after infection, and inflammatory responses and histologic alterations were analyzed. Flow cytometry results revealed that WT-infected mice had less leukocyte infiltration than APRIL Tg-infected mice. In WT-infected mice, infiltrates in gastric tissues were predominantly composed of T cells, mainly CD4 + for H. pylori and CD8 + for H. felis. In APRIL Tg-infected mice, leukocyte infiltrates were composed of B cells with few CD4 + T cells for both species. B cells expressed B surface markers compatible with a marginal zone origin. These results were confirmed by immunohistochemistry. B cells in particular were involved in lymphoepithelial lesions, a hallmark of gastric MALT lymphoma. Monoclonality was observed in a few infiltrates in the presence of lymphoepithelial lesions. These results confirm the importance of APRIL in the development of gastric lymphoid infiltrates induced by Helicobacter species in vivo. We believe that APRIL Tg mice infected by Helicobacter species may represent a novel animal model of gastric lymphomagenesis. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

RIG-I overexpression decreases mortality of cigarette smoke exposed mice during influenza A virus infection.

PubMed

Wang, Xiaoqiu; Wu, Wenxin; Zhang, Wei; Leland Booth, J; Duggan, Elizabeth S; Tian, Lili; More, Sunil; Zhao, Yan D; Sawh, Ravindranauth N; Liu, Lin; Zou, Ming-Hui; Metcalf, Jordan P

2017-09-02

Retinoic acid-inducible gene I (RIG-I) is an important regulator of virus-induced antiviral interferons (IFNs) and proinflammatory cytokines which participate in clearing viral infections. Cigarette smoke (CS) exposure increases the frequency and severity of respiratory tract infections. We generated a RIG-I transgenic (TG) mouse strain that expresses the RIG-I gene product under the control of the human lung specific surfactant protein C promoter. We compared the mortality and host immune responses of RIG-I TG mice and their litter-matched wild type (WT) mice following challenge with influenza A virus (IAV). RIG-I overexpression increased survival of IAV-infected mice. CS exposure increased mortality in WT mice infected with IAV. Remarkably, the effect of RIG-I overexpression on survival during IAV infection was enhanced in CS-exposed animals. CS-exposed IAV-infected WT mice had a suppressed innate response profile in the lung compared to sham-exposed IAV-infected WT mice in terms of the protein concentration, total cell count and inflammatory cell composition in the bronchoalveolar lavage fluid. RIG-I overexpression restored the innate immune response in CS-exposed mice to that seen in sham-exposed WT mice during IAV infection, and is likely responsible for enhanced survival in RIG-I TG mice as restoration preceded death of the animals. Our results demonstrate that RIG-I overexpression in mice is protective for CS enhanced susceptibility of smokers to influenza infection, and that CS mediated RIG-I suppression may be partially responsible for the increased morbidity and mortality of the mice exposed to IAV. Thus, optimizing the RIG-I response may be an important treatment strategy for CS-enhanced lung infections, particularly those due to IAV.

Virus Infections on Prion Diseased Mice Exacerbate Inflammatory Microglial Response

PubMed Central

Lins, Nara; Mourão, Luiz; Trévia, Nonata; Passos, Aline; Farias, José Augusto; Assunção, Jarila; Bento-Torres, João; Consentino Kronka Sosthenes, Marcia; Diniz, José Antonio Picanço; Vasconcelos, Pedro Fernando da Costa

2016-01-01

We investigated possible interaction between an arbovirus infection and the ME7 induced mice prion disease. C57BL/6, females, 6-week-old, were submitted to a bilateral intrahippocampal injection of ME7 prion strain (ME7) or normal brain homogenate (NBH). After injections, animals were organized into two groups: NBH (n = 26) and ME7 (n = 29). At 15th week after injections (wpi), animals were challenged intranasally with a suspension of Piry arbovirus 0.001% or with NBH. Behavioral changes in ME7 animals appeared in burrowing activity at 14 wpi. Hyperactivity on open field test, errors on rod bridge, and time reduction in inverted screen were detected at 15th, 19th, and 20th wpi respectively. Burrowing was more sensitive to earlier hippocampus dysfunction. However, Piry-infection did not significantly affect the already ongoing burrowing decline in the ME7-treated mice. After behavioral tests, brains were processed for IBA1, protease-resistant form of PrP, and Piry virus antigens. Although virus infection in isolation did not change the number of microglia in CA1, virus infection in prion diseased mice (at 17th wpi) induced changes in number and morphology of microglia in a laminar-dependent way. We suggest that virus infection exacerbates microglial inflammatory response to a greater degree in prion-infected mice, and this is not necessarily correlated with hippocampal-dependent behavioral deficits. PMID:28003864

Interactions among buffelgrass, phenanthrene and phenanthrene-degrading bacteria in gnotobiotic microcosms.

PubMed

Robert, Francoise M; Sun, Wenhao H; Toma, Marisa; Jones, Ryan K; Tang, Chung-Shih

2008-07-15

An experiment was undertaken in gnotobiotic microcosms to determine the role of buffelgrass (Cenchrus ciliaris) and a phenanthrene-degrading bacterium (strain PM600) in the degradation of phenanthrene. The Gram-negative bacterium was identified as a Sphingomonas sp. by 16S rRNA gene sequence analysis and as S. paucimobilis by biochemical tests (API 20 NE strips). Its yellow pigment corresponded to nostoxanthin and its cellular fatty acids were typical of the genus Sphingomonas. Moreover, it was devoid of lipopolysaccharides. Strain PM600 was tested for growth on mineral medium supplemented with No. 2 diesel, hexadecane, mineral oil, pristane, phenanthrene, and pyrene as single carbon sources. It was capable of utilizing phenanthrene only. In the gnotobiotic microcosms silica sand was either or not supplemented with 150 mg of phenanthrene kg(-1) sand, inoculated with strain PM600, and planted to sterile young seedlings of buffelgrass. After 28 days, 67% of the reduction of the phenanthrene concentration was assigned to degradation by the bacterium and ca. 20% to abiotic factors. No statistically significant effect of the young buffelgrass was found. In the absence of phenanthrene, the bacterial population significantly increased in the rhizosphere of buffelgrass. However, in the presence of buffelgrass and phenanthrene, the bacterial population preferentially responded to phenanthrene. The growth of buffelgrass was severely curtailed by phenanthrene in the absence of the bacterium. However, strain PM600 effectively protected buffelgrass against the phytotoxicity of phenanthrene.

Helminth infections predispose mice to pneumococcal pneumonia but not to other pneumonic pathogens.

PubMed

Apiwattanakul, Nopporn; Thomas, Paul G; Kuhn, Raymond E; Herbert, De'Broski R; McCullers, Jonathan A

2014-10-01

Pneumonia is the leading killer of children worldwide. Here, we report that helminth-infected mice develop fatal pneumonia when challenged with Streptococcus pneumoniae. Mice were chronically infected with either the flatworm Taenia crassiceps or the roundworm Heligmosomoides polygyrus. Upon challenge with a pneumonic type 3 strain of S. pneumoniae (A66.1), the worm-infected mice developed pneumonia at a rate and to a degree higher than age-matched control mice as measured by bioluminescent imaging and lung titers. This predisposition to pneumonia appears to be specific to S. pneumoniae, as worm-infected mice did not show evidence of increased morbidity when challenged with a lethal dose of influenza virus or sublethal doses of Staphylococcus aureus or Listeria monocytogenes. The defect was also present when worm-infected mice were challenged with a type 2 sepsis-causing strain (D39); an increased rate of pneumonia, decreased survival, and increased lung and blood titers were found. Pneumococcal colonization and immunity against acute otitis media were unaffected. Anti-helminthic treatment in the H. polygyrus model reversed this susceptibility. We conclude that helminth coinfection predisposes mice to fatal pneumococcal pneumonia by promoting increased outgrowth of bacteria in the lungs and blood. These data have broad implications for the prevention and treatment for pneumonia in the developing world, where helminth infections are endemic and pneumococcal pneumonia is common.

Increased Atherogenesis during Streptococcus mutans Infection in ApoE-null Mice

PubMed Central

Kesavalu, L.; Lucas, A.R.; Verma, R.K.; Liu, L.; Dai, E.; Sampson, E.; Progulske-Fox, A.

2012-01-01

Streptococcus mutans, a dental caries pathogen, also causes endocarditis and is detected in atheroscelerotic plaque. We investigated the potential for an invasive strain of S. mutans, OMZ175, to accelerate plaque growth in apolipoprotein E deficient (ApoEnull) mice without and with balloon angioplasty (BA) injury, a model of restenosis. ApoEnull mice were divided into 4 groups (N = 10), 2 with and 2 without BA. One each of the BA and non-BA groups was infected with S. mutans (Sm). S. mutans DNA, plaque area, inflammatory cell invasion, and Toll-like receptor (TLR) expression were measured at 6-20 weeks post-infection. S. mutans genomic DNA was detected in the aorta, liver, spleen, and heart. Plaque growth was significantly increased in infected mice with BA (Sm+BA) vs. those in the non-infected groups (p < 0.03). Plaque size was increased after infection without BA (Sm), but did not reach significance. Aortic specimens from both S. mutans and Sm+BA groups displayed increased numbers of macrophages, and TLR4 expression was increased in BA mice. In conclusion, S. mutans infection accelerated plaque growth, macrophage invasion, and TLR4 expression after angioplasty. S. mutans may also be associated with atherosclerotic plaque growth in non-injured arteries. PMID:22262633

Metabolome progression during early gut microbial colonization of gnotobiotic mice

PubMed Central

Marcobal, Angela; Yusufaly, Tahir; Higginbottom, Steven; Snyder, Michael; Sonnenburg, Justin L.; Mias, George I.

2015-01-01

The microbiome has been implicated directly in host health, especially host metabolic processes and development of immune responses. These are particularly important in infants where the gut first begins being colonized, and such processes may be modeled in mice. In this investigation we follow longitudinally the urine metabolome of ex-germ-free mice, which are colonized with two bacterial species, Bacteroides thetaiotaomicron and Bifidobacterium longum. High-throughput mass spectrometry profiling of urine samples revealed dynamic changes in the metabolome makeup, associated with the gut bacterial colonization, enabled by our adaptation of non-linear time-series analysis to urine metabolomics data. Results demonstrate both gradual and punctuated changes in metabolite production and that early colonization events profoundly impact the nature of small molecules circulating in the host. The identified small molecules are implicated in amino acid and carbohydrate metabolic processes, and offer insights into the dynamic changes occurring during the colonization process, using high-throughput longitudinal methodology. PMID:26118551

Reproduction of Epstein-Barr Virus Infection and Pathogenesis in Humanized Mice

PubMed Central

2014-01-01

Epstein-Barr virus (EBV) is etiologically associated with a variety of diseases including lymphoproliferative diseases, lymphomas, carcinomas, and autoimmune diseases. Humans are the only natural host of EBV and limited species of new-world monkeys can be infected with the virus in experimental conditions. Small animal models of EBV infection, required for evaluation of novel therapies and vaccines for EBV-associated diseases, have not been available. Recently the development of severely immunodeficient mouse strains enabled production of humanized mice in which human immune system components are reconstituted and express their normal functions. Humanized mice can serve as infection models for human-specific viruses such as EBV that target cells of the immune system. This review summarizes recent studies by the author's group addressing reproduction of EBV infection and pathogenesis in humanized mice. PMID:24605074

Zika virus infection confers protection against West Nile virus challenge in mice

PubMed Central

Vázquez-Calvo, Ángela; Blázquez, Ana-Belén; Escribano-Romero, Estela; Merino-Ramos, Teresa; Saiz, Juan-Carlos; Martín-Acebes, Miguel A; Jiménez de Oya, Nereida

2017-01-01

Flaviviruses are RNA viruses that constitute a worrisome threat to global human and animal health. Zika virus (ZIKV), which was initially reported to cause a mild disease, recently spread in the Americas, infecting millions of people. During this recent epidemic, ZIKV infection has been linked to serious neurological diseases and birth defects, specifically Guillain-Barrè syndrome (GBS) and microcephaly. Because information about ZIKV immunity remains scarce, we assessed the humoral response of immunocompetent mice to infection with three viral strains of diverse geographical origin (Africa, Asia and America). No infected animals showed any sign of disease or died after infection. However, specific neutralizing antibodies were elicited in all infected mice. Considering the rapid expansion of ZIKV throughout the American continent and its co-circulation with other medically relevant flaviviruses, such as West Nile virus (WNV), the induction of protective immunity between ZIKV and WNV was analyzed. Remarkably, protection after challenge with WNV was observed in mice previously infected with ZIKV, as survival rates were significantly higher than in control mice. Moreover, previous ZIKV infection enhanced the humoral immune response against WNV. These findings may be relevant in geographical areas where both ZIKV and WNV co-circulate, as well as for the future development of broad-spectrum flavivirus vaccines. PMID:28928416

Zika virus infection confers protection against West Nile virus challenge in mice.

PubMed

Vázquez-Calvo, Ángela; Blázquez, Ana-Belén; Escribano-Romero, Estela; Merino-Ramos, Teresa; Saiz, Juan-Carlos; Martín-Acebes, Miguel A; Jiménez de Oya, Nereida

2017-09-20

Flaviviruses are RNA viruses that constitute a worrisome threat to global human and animal health. Zika virus (ZIKV), which was initially reported to cause a mild disease, recently spread in the Americas, infecting millions of people. During this recent epidemic, ZIKV infection has been linked to serious neurological diseases and birth defects, specifically Guillain-Barrè syndrome (GBS) and microcephaly. Because information about ZIKV immunity remains scarce, we assessed the humoral response of immunocompetent mice to infection with three viral strains of diverse geographical origin (Africa, Asia and America). No infected animals showed any sign of disease or died after infection. However, specific neutralizing antibodies were elicited in all infected mice. Considering the rapid expansion of ZIKV throughout the American continent and its co-circulation with other medically relevant flaviviruses, such as West Nile virus (WNV), the induction of protective immunity between ZIKV and WNV was analyzed. Remarkably, protection after challenge with WNV was observed in mice previously infected with ZIKV, as survival rates were significantly higher than in control mice. Moreover, previous ZIKV infection enhanced the humoral immune response against WNV. These findings may be relevant in geographical areas where both ZIKV and WNV co-circulate, as well as for the future development of broad-spectrum flavivirus vaccines.

Obstructive Lymphangitis Precedes Colitis in Murine Norovirus-Infected Stat1-Deficient Mice.

PubMed

Seamons, Audrey; Treuting, Piper M; Meeker, Stacey; Hsu, Charlie; Paik, Jisun; Brabb, Thea; Escobar, Sabine S; Alexander, Jonathan S; Ericsson, Aaron; Smith, Jason G; Maggio-Price, Lillian

2018-05-17

Murine norovirus (MNV) is an RNA virus that can prove lethal in mice with impaired innate immunity. We found that MNV-4 infection of Stat1 -/- mice was not lethal, but produced a 100% penetrant, previously undescribed lymphatic phenotype characterized by chronic-active lymphangitis with hepatitis, splenitis, and chronic cecal and colonic inflammation. Lesion pathogenesis progressed from early ileal enteritis and regional dilated lymphatics to lymphangitis, granulomatous changes in the liver and spleen, and, ultimately, typhlocolitis. Lesion development was neither affected by antibiotics nor reproduced by infection with another enteric RNA virus, rotavirus. MNV-4 infection in Stat1 -/- mice decreased expression of vascular endothelial growth factor (Vegf) receptor 3, Vegf-c, and Vegf-d and increased interferon (Ifn)-γ, tumor necrosis factor-α, and inducible nitric oxide synthase. However, anti-IFN-γ and anti-tumor necrosis factor-α antibody treatment did not attenuate the histologic lesions. Studies in Ifnαβγr -/- mice suggested that canonical signaling via interferon receptors did not cause MNV-4-induced disease. Infected Stat1 -/- mice had increased STAT3 phosphorylation and expressed many STAT3-regulated genes, consistent with our findings of increased myeloid cell subsets and serum granulocyte-specific colony-stimulating factor, which are also associated with increased STAT3 activity. In conclusion, in Stat1 -/- mice, MNV-4 induces lymphatic lesions similar to those seen in Crohn disease as well as hepatitis, splenitis, and typhlocolitis. MNV-4-infected Stat1 -/- mice may be a useful model to study mechanistic associations between viral infections, lymphatic dysfunction, and intestinal inflammation in a genetically susceptible host. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Tissue factor deficiency increases alveolar hemorrhage and death in influenza A virus-infected mice.

PubMed

Antoniak, S; Tatsumi, K; Hisada, Y; Milner, J J; Neidich, S D; Shaver, C M; Pawlinski, R; Beck, M A; Bastarache, J A; Mackman, N

2016-06-01

Essentials H1N1 Influenza A virus (IAV) infection is a hemostatic challenge for the lung. Tissue factor (TF) on lung epithelial cells maintains lung hemostasis after IAV infection. Reduced TF-dependent activation of coagulation leads to alveolar hemorrhage. Anticoagulation might increase the risk for hemorrhages into the lung during severe IAV infection. Background Influenza A virus (IAV) infection is a common respiratory tract infection that causes considerable morbidity and mortality worldwide. Objective To investigate the effect of genetic deficiency of tissue factor (TF) in a mouse model of IAV infection. Methods Wild-type mice, low-TF (LTF) mice and mice with the TF gene deleted in different cell types were infected with a mouse-adapted A/Puerto Rico/8/34 H1N1 strain of IAV. TF expression was measured in the lungs, and bronchoalveolar lavage fluid (BALF) was collected to measure extracellular vesicle TF, activation of coagulation, alveolar hemorrhage, and inflammation. Results IAV infection of wild-type mice increased lung TF expression, activation of coagulation and inflammation in BALF, but also led to alveolar hemorrhage. LTF mice and mice with selective deficiency of TF in lung epithelial cells had low basal levels of TF and failed to increase TF expression after infection; these two strains of mice had more alveolar hemorrhage and death than controls. In contrast, deletion of TF in either myeloid cells or endothelial cells and hematopoietic cells did not increase alveolar hemorrhage or death after IAV infection. These results indicate that TF expression in the lung, particularly in epithelial cells, is required to maintain alveolar hemostasis after IAV infection. Conclusion Our study indicates that TF-dependent activation of coagulation is required to limit alveolar hemorrhage and death after IAV infection. © 2016 International Society on Thrombosis and Haemostasis.

T lymphocyte-mediated protection against Pseudomonas aeruginosa infection in granulocytopenic mice.

PubMed Central

Powderly, W G; Pier, G B; Markham, R B

1986-01-01

BALB/c mice immunized with Pseudomonas aeruginosa immunotype 1 polysaccharide develop protective T cell immunity to bacterial challenge. In vitro, T cells from immunized mice kill P. aeruginosa by production of a bactericidal lymphokine. The present study demonstrates that adoptive transfer of T cells from immunized BALB/c mice to granulocytopenic mice resulted in 97% survival on challenge with P. aeruginosa, compared with 17% survival with adoptive transfer of T cells from nonimmune BALB/c mice. This protection is specifically elicited by reexposure to the original immunizing antigen; adoptive recipients cannot withstand challenge with immunotype 3 P. aeruginosa. However, the adoptive recipients do survive simultaneous infection with both P. aeruginosa immunotypes 1 and 3. Adoptive transfer of T cells from the congenic CB.20 mice, which are unable to kill P. aeruginosa in vitro, provides only 20% protection to granulocytopenic mice. These studies indicate that transfer of specific immune T lymphocytes can significantly enhance the resistance to P. aeruginosa infection in granulocytopenic mice. PMID:2426306

Hemojuvelin regulates the innate immune response to peritoneal bacterial infection in mice.

PubMed

Wu, Qian; Shen, Yuanyuan; Tao, Yunlong; Wei, Jiayu; Wang, Hao; An, Peng; Zhang, Zhuzhen; Gao, Hong; Zhou, Tianhua; Wang, Fudi; Min, Junxia

2017-01-01

Hereditary hemochromatosis and iron imbalance are associated with susceptibility to bacterial infection; however, the underlying mechanisms are poorly understood. Here, we performed in vivo bacterial infection screening using several mouse models of hemochromatosis, including Hfe ( Hfe -/- ), hemojuvelin ( Hjv -/- ), and macrophage-specific ferroportin-1 ( Fpn1 fl/fl ; LysM-Cre + ) knockout mice. We found that Hjv -/- mice, but not Hfe -/- or Fpn1 fl/fl ; LysM-Cre + mice, are highly susceptible to peritoneal infection by both Gram-negative and Gram-positive bacteria. Interestingly, phagocytic cells in the peritoneum of Hjv -/- mice have reduced bacterial clearance, IFN-γ secretion, and nitric oxide production; in contrast, both cell migration and phagocytosis are normal. Expressing Hjv in RAW264.7 cells increased the level of phosphorylated Stat1 and nitric oxide production. Moreover, macrophage-specific Hjv knockout mice are susceptible to bacterial infection. Finally, we found that Hjv facilitates the secretion of IFN-γ via the IL-12/Jak2/Stat4 signaling pathway. Together, these findings reveal a novel protective role of Hjv in the early stages of antimicrobial defense.

Spectrum of disease outcomes in mice infected with YFV-17D

PubMed Central

Erickson, Andrea K.

2015-01-01

The host and viral factors that influence disease outcome during flavivirus infections are not fully understood. Using the live attenuated yellow fever virus (YFV) vaccine strain 17D as a model system we evaluated how viral dose, inoculation route and immunopathogenesis contributed to disease outcome in mice deficient in the type I IFN response. We found that YFV-17D infection of IFN-α/β receptor knockout mice resulted in three distinct disease outcomes: no clinical signs of disease, fatal viscerotropic disease or fatal neurotropic disease. Interestingly, viral load at disease onset did not correlate with disease outcome. However, we found increased immune infiltrates in the brain tissues of mice that developed neurotropic disease. Additionally, mice that developed viscerotropic disease, as characterized by liver and spleen pathology and/or intestinal haemorrhage, had significantly elevated levels of alanine aminotransferase, monocyte chemotactic protein and IFN-inducible protein (IP)-10 as compared with mice with no clinical signs of disease or neurotropic disease. Furthermore, mice treated with recombinant IP-10 throughout YFV-17D infection showed increased mortality and an increased percentage of mice with viscerotropic disease. Our results demonstrated that viral load did not correlate with pathogenesis, and the host immune response played a pivotal role in disease outcome and contributed to YFV-17D pathogenesis in mice. PMID:25646269

Spectrum of disease outcomes in mice infected with YFV-17D.

PubMed

Erickson, Andrea K; Pfeiffer, Julie K

2015-06-01

The host and viral factors that influence disease outcome during flavivirus infections are not fully understood. Using the live attenuated yellow fever virus (YFV) vaccine strain 17D as a model system we evaluated how viral dose, inoculation route and immunopathogenesis contributed to disease outcome in mice deficient in the type I IFN response. We found that YFV-17D infection of IFN-α/β receptor knockout mice resulted in three distinct disease outcomes: no clinical signs of disease, fatal viscerotropic disease or fatal neurotropic disease. Interestingly, viral load at disease onset did not correlate with disease outcome. However, we found increased immune infiltrates in the brain tissues of mice that developed neurotropic disease. Additionally, mice that developed viscerotropic disease, as characterized by liver and spleen pathology and/or intestinal haemorrhage, had significantly elevated levels of alanine aminotransferase, monocyte chemotactic protein and IFN-inducible protein (IP)-10 as compared with mice with no clinical signs of disease or neurotropic disease. Furthermore, mice treated with recombinant IP-10 throughout YFV-17D infection showed increased mortality and an increased percentage of mice with viscerotropic disease. Our results demonstrated that viral load did not correlate with pathogenesis, and the host immune response played a pivotal role in disease outcome and contributed to YFV-17D pathogenesis in mice. © 2015 The Authors.

Treatment of Mycobacterium intracellulare Infected Mice with Walter Reed Compound H

DTIC Science & Technology

1980-09-25

including Mycobacterium tuberculosis, Mycobacterium leprae , Staphylococcusaureus, Pseudomonas aeruginosa, Escherichia coli, enterococ----ci, Neissr•~n...97 SAD "Treatment of Mycobacterium intracellulare Infected Mice with Walter Reed Compound H" Final Comprehensive Report J. Kenneth McClatchy, Ph.D...REPORT & PERIOD COVERED "TREATMENT OF MYCOBACTERIUM INTRACELLULARE - Final Comprehensive Report INFECTED MICE WITH WALTER REED COMPOUND H"li G

Infection with the Lyme disease pathogen suppresses innate immunity in mice with diet‐induced obesity

PubMed Central

Zlotnikov, Nataliya; Javid, Ashkan; Ahmed, Mijhgan; Eshghi, Azad; Tang, Tian Tian; Arya, Anoop; Bansal, Anil; Matar, Fatima; Parikh, Maitry; Ebady, Rhodaba; Koh, Adeline; Gupta, Nupur; Song, Peng; Zhang, Yang; Newbigging, Susan; Wormser, Gary P.; Schwartz, Ira; Inman, Robert; Glogauer, Michael

2016-01-01

Abstract Obesity is a major global public health concern. Immune responses implicated in obesity also control certain infections. We investigated the effects of high‐fat diet‐induced obesity (DIO) on infection with the Lyme disease bacterium Borrelia burgdorferi in mice. DIO was associated with systemic suppression of neutrophil‐ and macrophage‐based innate immune responses. These included bacterial uptake and cytokine production, and systemic, progressive impairment of bacterial clearance, and increased carditis severity. B. burgdorferi‐infected mice fed normal diet also gained weight at the same rate as uninfected mice fed high‐fat diet, toll‐like receptor 4 deficiency rescued bacterial clearance defects, which greater in female than male mice, and killing of an unrelated bacterium (Escherichia coli) by bone marrow‐derived macrophages from obese, B. burgdorferi‐infected mice was also affected. Importantly, innate immune suppression increased with infection duration and depended on cooperative and synergistic interactions between DIO and B. burgdorferi infection. Thus, obesity and B. burgdorferi infection cooperatively and progressively suppressed innate immunity in mice. PMID:27794208

Infection with the Lyme disease pathogen suppresses innate immunity in mice with diet-induced obesity.

PubMed

Zlotnikov, Nataliya; Javid, Ashkan; Ahmed, Mijhgan; Eshghi, Azad; Tang, Tian Tian; Arya, Anoop; Bansal, Anil; Matar, Fatima; Parikh, Maitry; Ebady, Rhodaba; Koh, Adeline; Gupta, Nupur; Song, Peng; Zhang, Yang; Newbigging, Susan; Wormser, Gary P; Schwartz, Ira; Inman, Robert; Glogauer, Michael; Moriarty, Tara J

2017-05-01

Obesity is a major global public health concern. Immune responses implicated in obesity also control certain infections. We investigated the effects of high-fat diet-induced obesity (DIO) on infection with the Lyme disease bacterium Borrelia burgdorferi in mice. DIO was associated with systemic suppression of neutrophil- and macrophage-based innate immune responses. These included bacterial uptake and cytokine production, and systemic, progressive impairment of bacterial clearance, and increased carditis severity. B. burgdorferi-infected mice fed normal diet also gained weight at the same rate as uninfected mice fed high-fat diet, toll-like receptor 4 deficiency rescued bacterial clearance defects, which greater in female than male mice, and killing of an unrelated bacterium (Escherichia coli) by bone marrow-derived macrophages from obese, B. burgdorferi-infected mice was also affected. Importantly, innate immune suppression increased with infection duration and depended on cooperative and synergistic interactions between DIO and B. burgdorferi infection. Thus, obesity and B. burgdorferi infection cooperatively and progressively suppressed innate immunity in mice. © 2016 The Authors Cellular Microbiology Published by John Wiley & Sons Ltd.

Cooperative role of macrophages and neutrophils in host Antiprotozoan resistance in mice acutely infected with Cryptosporidium parvum.

PubMed

Takeuchi, Dan; Jones, Vickie C; Kobayashi, Makiko; Suzuki, Fujio

2008-08-01

Severe experimental infections with Cryptosporidium parvum have been reported in immunocompromised animals such as SCID mice (mice without functional T cells and B cells). In a C. parvum infection with 1 x 10(6) oocysts/mouse in SCID beige (SCIDbg) mice (SCID mice lacking functional NK cells), oocyst shedding was first demonstrated 18 days after infection. However, shedding was shown as early as 3 days after the same infection in SCIDbgMN mice. All of the SCIDbgMN mice died within 16 days of C. parvum infection, while 100% of the SCIDbg mice exposed to the parasite survived. SCIDbgMN mice are SCIDbg mice depleted of functional macrophages (Mphi) and neutrophils (PMN), suggesting that the severity early after C. parvum infection is strongly influenced by the functions of Mphi and PMN. All SCIDbgMN mice orally infected with a lethal dose of C. parvum survived after they were inoculated with Mphi from SCIDbg mice exposed to C. parvum (CP-Mphi) or resident Mphi previously cultured with PMN from C. parvum-infected SCIDbg mice (CP-PMN). However, all SCIDbgMN mice inoculated with CP-PMN alone or resident Mphi alone died after C. parvum infection. CP-Mphi were identified as classically activated Mphi (M1Mphi), and CP-PMN were characterized as PMN-I. In in vitro studies, resident Mphi converted to M1Mphi after transwell cultivation with CP-PMN. These results indicate that the resistance of SCIDbg mice early after C. parvum infection is displayed through the function of M1Mphi which are converted from resident Mphi influenced by CP-PMN (PMN-I).

La Crosse virus infectivity, pathogenesis, and immunogenicity in mice and monkeys

PubMed Central

Bennett, Richard S; Cress, Christina M; Ward, Jerrold M; Firestone, Cai-Yen; Murphy, Brian R; Whitehead, Stephen S

2008-01-01

Background La Crosse virus (LACV), family Bunyaviridae, was first identified as a human pathogen in 1960 after its isolation from a 4 year-old girl with fatal encephalitis in La Crosse, Wisconsin. LACV is a major cause of pediatric encephalitis in North America and infects up to 300,000 persons each year of which 70–130 result in severe disease of the central nervous system (CNS). As an initial step in the establishment of useful animal models to support vaccine development, we examined LACV infectivity, pathogenesis, and immunogenicity in both weanling mice and rhesus monkeys. Results Following intraperitoneal inoculation of mice, LACV replicated in various organs before reaching the CNS where it replicates to high titer causing death from neurological disease. The peripheral site where LACV replicates to highest titer is the nasal turbinates, and, presumably, LACV can enter the CNS via the olfactory neurons from nasal olfactory epithelium. The mouse infectious dose50 and lethal dose50 was similar for LACV administered either intranasally or intraperitoneally. LACV was highly infectious for rhesus monkeys and infected 100% of the animals at 10 PFU. However, the infection was asymptomatic, and the monkeys developed a strong neutralizing antibody response. Conclusion In mice, LACV likely gains access to the CNS via the blood stream or via olfactory neurons. The ability to efficiently infect mice intranasally raises the possibility that LACV might use this route to infect its natural hosts. Rhesus monkeys are susceptible to LACV infection and develop strong neutralizing antibody responses after inoculation with as little as 10 PFU. Mice and rhesus monkeys are useful animal models for LACV vaccine immunologic testing although the rhesus monkey model is not optimal. PMID:18267012

Developmental plasticity of bacterial colonies and consortia in germ-free and gnotobiotic settings

PubMed Central

2012-01-01

Background Bacteria grown on semi-solid media can build two types of multicellular structures, depending on the circumstances. Bodies (colonies) arise when a single clone is grown axenically (germ-free), whereas multispecies chimeric consortia contain monoclonal microcolonies of participants. Growth of an axenic colony, mutual interactions of colonies, and negotiation of the morphospace in consortial ecosystems are results of intricate regulatory and metabolic networks. Multicellular structures developed by Serratia sp. are characteristically shaped and colored, forming patterns that reflect their growth conditions (in particular medium composition and the presence of other bacteria). Results Building on our previous work, we developed a model system for studying ontogeny of multicellular bacterial structures formed by five Serratia sp. morphotypes of two species grown in either "germ-free" or "gnotobiotic" settings (i.e. in the presence of bacteria of other conspecific morphotype, other Serratia species, or E. coli). Monoclonal bodies show regular and reproducible macroscopic appearance of the colony, as well as microscopic pattern of its growing margin. Standard development can be modified in a characteristic and reproducible manner in close vicinity of other bacterial structures (or in the presence of their products). Encounters of colonies with neighbors of a different morphotype or species reveal relationships of dominance, cooperation, or submission; multiple interactions can be summarized in "rock – paper – scissors" network of interrelationships. Chimerical (mixed) plantings consisting of two morphotypes usually produced a “consortium” whose structure is consistent with the model derived from interaction patterns observed in colonies. Conclusions Our results suggest that development of a bacterial colony can be considered analogous to embryogenesis in animals, plants, or fungi: to proceed, early stages require thorough insulation from the rest of

Salmonella typhimurium infection in high and low antibody responder mice: inverse correlation between antibody responsiveness and resistance to infection.

PubMed

Sant'Anna, O A; Massa, S; Mouton, D; Bouthillier, Y; Mevel, J C; Ibanez, O M; Vassao, R; de Franco, M; Bellinati, R; Siqueira, M

1989-12-01

Susceptibility to Salmonella typhimurium infection was compared in H (high Ab responder) and L (low Ab responder) mice obtained by several selective breeding experiments (Selections I, II, III, IV and IV A). H mice were always much more susceptible to infection than their L mice counterparts within a continuous LD 50 variation range. In three of the selections (I, II and IV A) the low responsiveness character is known to result mainly from rapid Ag degradation in L mice macrophages. It was hypothesized that resistance to multiplication of intracellular pathogens could be related to an increased catabolic activity towards Ag. This was actually demonstrated, in F2 segregant hybrids of selection IV A, by the significant inverse correlation between capacity for Ab production and resistance to infection.

Visual and Motor Deficits in Grown-up Mice with Congenital Zika Virus Infection.

PubMed

Cui, Liyuan; Zou, Peng; Chen, Er; Yao, Hao; Zheng, Hao; Wang, Qian; Zhu, Jing-Ning; Jiang, Shibo; Lu, Lu; Zhang, Jiayi

2017-06-01

Human infants with congenital Zika virus (ZIKV) infection exhibit a range of symptoms including microcephaly, intracranial calcifications, macular atrophy and arthrogryposis. More importantly, prognosis data have lagged far behind the recent outbreak of ZIKV in 2015. In this work, we allow congenitally ZIKV-infected mice to grow into puberty. These mice exhibited motor incoordination and visual dysfunctions, which can be accounted by anatomical defects in the retina and cerebellar cortex. In contrary, anxiety level of the ZIKV-infected mice is normal. The spectrum of anatomical and behavioral deficits is consistent across different mice. Our data provided evidence that may help predict the public health burden in terms of prognosis of ZIKV-related congenital brain malformations in an animal model. Our study provided behavioral evaluation for the prognosis of congenital ZIKV infection and provides a platform for screening and evaluation of drugs candidates and treatment aiming at improving regeneration of infected neurons to prevent sequelae caused by ZIKV infection of fetus. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Acute and chronic neurological consequences of early-life Zika virus infection in mice.

PubMed

Nem de Oliveira Souza, Isis; Frost, Paula S; França, Julia V; Nascimento-Viana, Jéssica B; Neris, Rômulo L S; Freitas, Leandro; Pinheiro, Daniel J L L; Nogueira, Clara O; Neves, Gilda; Chimelli, Leila; De Felice, Fernanda G; Cavalheiro, Ésper A; Ferreira, Sergio T; Assunção-Miranda, Iranaia; Figueiredo, Claudia P; Da Poian, Andrea T; Clarke, Julia R

2018-06-06

Although congenital Zika virus (ZIKV) exposure has been associated with microcephaly and other neurodevelopmental disorders, long-term consequences of perinatal infection are largely unknown. We evaluated short- and long-term neuropathological and behavioral consequences of neonatal ZIKV infection in mice. ZIKV showed brain tropism, causing postnatal-onset microcephaly and several behavioral deficits in adulthood. During the acute phase of infection, mice developed frequent seizures, which were reduced by tumor necrosis factor-α (TNF-α) inhibition. During adulthood, ZIKV replication persisted in neonatally infected mice, and the animals showed increased susceptibility to chemically induced seizures, neurodegeneration, and brain calcifications. Altogether, the results show that neonatal ZIKV infection has long-term neuropathological and behavioral complications in mice and suggest that early inhibition of TNF-α-mediated neuroinflammation might be an effective therapeutic strategy to prevent the development of chronic neurological abnormalities. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Rhinovirus infection of allergen-sensitized and -challenged mice induces eotaxin release from functionally polarized macrophages.

PubMed

Nagarkar, Deepti R; Bowman, Emily R; Schneider, Dina; Wang, Qiong; Shim, Jee; Zhao, Ying; Linn, Marisa J; McHenry, Christina L; Gosangi, Babina; Bentley, J Kelley; Tsai, Wan C; Sajjan, Umadevi S; Lukacs, Nicholas W; Hershenson, Marc B

2010-08-15

Human rhinovirus is responsible for the majority of virus-induced asthma exacerbations. To determine the immunologic mechanisms underlying rhinovirus (RV)-induced asthma exacerbations, we combined mouse models of allergic airways disease and human rhinovirus infection. We inoculated OVA-sensitized and challenged BALB/c mice with rhinovirus serotype 1B, a minor group strain capable of infecting mouse cells. Compared with sham-infected, OVA-treated mice, virus-infected mice showed increased lung infiltration with neutrophils, eosinophils and macrophages, airway cholinergic hyperresponsiveness, and increased lung expression of cytokines including eotaxin-1/CCL11, IL-4, IL-13, and IFN-gamma. Administration of anti-eotaxin-1 attenuated rhinovirus-induced airway eosinophilia and responsiveness. Immunohistochemical analysis showed eotaxin-1 in the lung macrophages of virus-infected, OVA-treated mice, and confocal fluorescence microscopy revealed colocalization of rhinovirus, eotaxin-1, and IL-4 in CD68-positive cells. RV inoculation of lung macrophages from OVA-treated, but not PBS-treated, mice induced expression of eotaxin-1, IL-4, and IL-13 ex vivo. Macrophages from OVA-treated mice showed increased expression of arginase-1, Ym-1, Mgl-2, and IL-10, indicating a shift in macrophage activation status. Depletion of macrophages from OVA-sensitized and -challenged mice reduced eosinophilic inflammation and airways responsiveness following RV infection. We conclude that augmented airway eosinophilic inflammation and hyperresponsiveness in RV-infected mice with allergic airways disease is directed in part by eotaxin-1. Airway macrophages from mice with allergic airways disease demonstrate a change in activation state characterized in part by altered eotaxin and IL-4 production in response to RV infection. These data provide a new paradigm to explain RV-induced asthma exacerbations.

Effects of recombinant granulocyte-colony stimulating factor administration during Mycobacterium avium infection in mice

PubMed Central

Gonçalves, A S; Appelberg, R

2001-01-01

Granulocyte colony-stimulating factor (G-CSF) administration in vivo has been shown to improve the defence mechanisms against infection by different microbes. Here we evaluated a possible protective role of this molecule in a mouse model of mycobacterial infection. The administration of recombinant G-CSF promoted an extensive blood neutrophilia but failed to improve the course of Mycobacterium avium infection in C57Bl/6 or beige mice. G-CSF administration also failed to improve the efficacy of a triple chemotherapeutic regimen (clarithromycin + ethambutol + rifabutin). G-CSF treatment did not protect interleukin-10 gene disrupted mice infected with M. avium. Spleen cells from infected mice treated with G-CSF had a decreased priming for antigen-specific production of interferon gamma compared to control infected mice. Our data do not substantiate previous reports on the protective activity of G-CSF in antimycobacterial immunity using mouse models. PMID:11422200

Targeted photodynamic therapy of established soft-tissue infections in mice

NASA Astrophysics Data System (ADS)

Gad, Faten; Zahra, Touqir; Hasan, Tayyaba; Hamblin, Michael R.

2004-06-01

The worldwide rise in antibiotic resistance necessitates the development of novel antimicrobial strategies. Although many workers have used photodynamic therapy (PDT) to kill bacteria in vitro, the use of this approach has seldom been reported in vivo in animal models of infection. We have previously described the first use of PDT to treat excisional wound infections by Gram-negative bacteria in living mice. However these infected wound models used a short time after infection (30 min) before PDT. We now report on the use of PDT to treat an established soft-tissue infection in mice. We used Staphylococcus aureus stably transformed with a Photorhabdus luminescens lux operon (luxABCDE) that was genetically modified to be functional in Gram-positive bacteria. These engineered bacteria emitted bioluminescence allowing the progress of the infection to be monitored in both space and time with a lowlight imaging charged couple device (CCD) camera. One million cells were injected into one or both thigh muscles of mice that had previously been rendered neutropenic by cyclophosphamide administration. Twenty-four hours later the bacteria had multiplied more than one hundred-fold, and poly-L-lysine chlorin(e6) conjugate or free chlorin(e6) was injected into one area of infected muscle and imaged with the CCD camera. Thirty-minutes later red light from a diode laser was delivered as a surface spot or by interstitial fiber into the infection. There was a lightdose dependent loss of bioluminescence (to < 5% of that seen in control infections) not seen in untreated or light alone treated infections, but in some cases the infection recurred. Conjugate alone led to a lesser reduction in bioluminescence. Infections treated with free chlorin(e6) responded less and the infection subsequently increased over the succeeding days, probably due to PDT-mediated tissue damage. PDT-treated infected legs healed better than legs with untreated infections. This data shows that PDT may have

Efficacy of Urtoxazumab (TMA-15 Humanized Monoclonal Antibody Specific for Shiga Toxin 2) Against Post-Diarrheal Neurological Sequelae Caused by Escherichia coli O157:H7 Infection in the Neonatal Gnotobiotic Piglet Model.

PubMed

Moxley, Rodney A; Francis, David H; Tamura, Mizuho; Marx, David B; Santiago-Mateo, Kristina; Zhao, Mojun

2017-01-26

Enterohemorrhagic Escherichia coli (EHEC) is the most common cause of hemorrhagic colitis and hemolytic uremic syndrome in human patients, with brain damage and dysfunction the main cause of acute death. We evaluated the efficacy of urtoxazumab (TMA-15, Teijin Pharma Limited), a humanized monoclonal antibody against Shiga toxin (Stx) 2 for the prevention of brain damage, dysfunction, and death in a piglet EHEC infection model. Forty-five neonatal gnotobiotic piglets were inoculated orally with 3 × 10⁸ colony-forming units of EHEC O157:H7 strain EDL933 (Stx1⁺, Stx2⁺) when 22-24 h old. At 24 h post-inoculation, piglets were intraperitoneally administered placebo or TMA-15 (0.3, 1.0 or 3.0 mg/kg body weight). Compared to placebo ( n = 10), TMA-15 ( n = 35) yielded a significantly greater probability of survival, length of survival, and weight gain ( p <0.05). The efficacy of TMA-15 against brain lesions and death was 62.9% ( p = 0.0004) and 71.4% ( p = 0.0004), respectively. These results suggest that TMA-15 may potentially prevent or reduce vascular necrosis and infarction of the brain attributable to Stx2 in human patients acutely infected with EHEC. However, we do not infer that TMA-15 treatment will completely protect human patients infected with EHEC O157:H7 strains that produce both Stx1 and Stx2.

NON-FATAL INFECTION OF MICE FOLLOWING INTRACEREBRAL INOCULATION OF YELLOW FEVER VIRUS

PubMed Central

Fox, John P.

1943-01-01

Observations have been reported which indicate that mice inoculated intracerebrally with active yellow fever virus may develop an infection which is not only non-fatal but may also be completely inapparent. The most extensive observations were made on mice which showed signs of infection but were still alive 22 days after inoculation with virus of one or another of several 17D substrains. In such cases, the infection usually progressed no further and partial or complete recovery often ensued. Agents other than yellow fever virus were excluded as a significant cause of such nonfatal infections by the failure of repeated attempts to isolate other infective agents, by the demonstration of antibodies against yellow fever virus in the sera of the mice, and by the demonstration of a high degree of resistance on the part of such surviving mice to reinoculation with large doses of neurotropic yellow fever virus. Completely inapparent infections with 17D virus were also shown to occur. Studies of apparently normal survivors of 17D virus titrations revealed a small but significant number of animals resistant to intracerebral challenge with neurotropic yellow fever virus. Further, pooled sera from such mice were shown to contain specific protective antibodies. The occurrence of non-fatal infections with 17D virus was found related to virus dose and substrain. Small doses of virus provoked a significantly higher proportion of non-fatal infections than large doses; while different 17D substrains, tested over equivalent ranges of virus dose, varied greatly with respect to the proportion of infections which did not terminate with death. In the case of two substrains (17DD low and 17D3), non-fatal infections (as demonstrated by resistance to intracerebral challenge with neurotropic virus) were sufficiently frequent to cause an increase, when included in the computation of the infective titers, of 25 per cent above the figures based on deaths alone. The demonstration of non

Immunopathological Changes in the Brain of Immunosuppressed Mice Experimentally Infected with Toxocara canis

PubMed Central

Eid, Mohamed M.; El-Kowrany, Samy I.; Othman, Ahmad A.; Gendy, Dina I. El; Saied, Eman M.

2015-01-01

Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection. PMID:25748709

Protection of mice against Giardia muris infection.

PubMed Central

Roberts-Thomson, I C; Mitchell, G F

1979-01-01

Strains of mice showing relatively rapid (BALB/c) and defective (C3H/He) spontaneous elimination of Giardia muris displayed marked differences in the degree of resistance to infection induced by prior injection of trophozoites in Freund complete adjuvant. PMID:468385

Detection of murine cytomegalovirus DNA in circulating leukocytes harvested during acute infection of mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bale, J.F. Jr.; O'Neil, M.E.

1989-06-01

The authors used virus assay and in situ hybridization with a cloned fragment of the murine cytomegalovirus (MCMV) genome to study MCMV infection of circulating leukocytes harvested from 3-week-old BALB/c, C57BL/6, and C3H mice infected with MCMV intraperitoneally. Infectious virus or MCMV DNA was detected in leukocytes on days 1 through 21 of infection in BALB/c mice and on days 3 through 7 in C57BL/6 mice. On days 5 and 7, MCMV DNA or infectious virus was detected in the leukocytes of 17 (94%) of 18 BALB/c mice and 10 (59%) of 17 C57BL/6 mice. In both strains infection peakedmore » on days 5 and 7, when as many as 0.01 to 0.1% of the circulating leukocytes contained MCMV DNA. In C3H mice, however, infectious virus was rarely recovered from leukocyte fractions and MCMV DNA was detected in the circulating leukocytes of only one animal. Circulating leukocytes may have an important role in the dissemination of CMV infections in susceptible hosts.« less

Serum Metabolic Profiling of Oocyst-Induced Toxoplasma gondii Acute and Chronic Infections in Mice Using Mass-Spectrometry

PubMed Central

Zhou, Chun-Xue; Cong, Wei; Chen, Xiao-Qing; He, Shen-Yi; Elsheikha, Hany M.; Zhu, Xing-Quan

2018-01-01

Toxoplasma gondii is an obligate intracellular parasite causing severe diseases in immunocompromised individuals and congenitally infected neonates, such as encephalitis and chorioretinitis. This study aimed to determine whether serum metabolic profiling can (i) identify metabolites associated with oocyst-induced T. gondii infection and (ii) detect systemic metabolic differences between T. gondii-infected mice and controls. We performed the first global metabolomics analysis of mice serum challenged with 100 sporulated T. gondii Pru oocysts (Genotype II). Sera from acutely infected mice (11 days post-infection, dpi), chronically infected mice (33 dpi) and control mice were collected and analyzed using LC-MS/MS platform. Following False Discovery Rate filtering, we identified 3871 and 2825 ions in ESI+ or ESI− mode, respectively. Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) identified metabolomic profiles that clearly differentiated T. gondii-infected and -uninfected serum samples. Acute infection significantly influenced the serum metabolome. Our results identified common and uniquely perturbed metabolites and pathways. Acutely infected mice showed perturbations in metabolites associated with glycerophospholipid metabolism, biosynthesis of amino acid, and tyrosine metabolism. These findings demonstrated that acute T. gondii infection induces a global perturbation of mice serum metabolome, providing new insights into the mechanisms underlying systemic metabolic changes during early stage of T. gondii infection. PMID:29354104

Respiratory Syncytial Virus Infections Enhance Cigarette Smoke Induced COPD in Mice

PubMed Central

Foronjy, Robert F.; Dabo, Abdoulaye J.; Taggart, Clifford C.; Weldon, Sinead; Geraghty, Patrick

2014-01-01

Respiratory syncytial viral (RSV) infections are a frequent cause of chronic obstructive pulmonary disease (COPD) exacerbations, which are a major factor in disease progression and mortality. RSV is able to evade antiviral defenses to persist in the lungs of COPD patients. Though RSV infection has been identified in COPD, its contribution to cigarette smoke-induced airway inflammation and lung tissue destruction has not been established. Here we examine the long-term effects of cigarette smoke exposure, in combination with monthly RSV infections, on pulmonary inflammation, protease production and remodeling in mice. RSV exposures enhanced the influx of macrophages, neutrophils and lymphocytes to the airways of cigarette smoke exposed C57BL/6J mice. This infiltration of cells was most pronounced around the vasculature and bronchial airways. By itself, RSV caused significant airspace enlargement and fibrosis in mice and these effects were accentuated with concomitant smoke exposure. Combined stimulation with both smoke and RSV synergistically induced cytokine (IL-1α, IL-17, IFN-γ, KC, IL-13, CXCL9, RANTES, MIF and GM-CSF) and protease (MMP-2, -8, -12, -13, -16 and cathepsins E, S, W and Z) expression. In addition, RSV exposure caused marked apoptosis within the airways of infected mice, which was augmented by cigarette smoke exposure. RSV and smoke exposure also reduced protein phosphatase 2A (PP2A) and protein tyrosine phosphates (PTP1B) expression and activity. This is significant as these phosphatases counter smoke-induced inflammation and protease expression. Together, these findings show for the first time that recurrent RSV infection markedly enhances inflammation, apoptosis and tissue destruction in smoke-exposed mice. Indeed, these results indicate that preventing RSV transmission and infection has the potential to significantly impact on COPD severity and progression. PMID:24587397

Ultra-low dose of Mycobacterium tuberculosis aerosol creates partial infection in mice.

PubMed

Saini, Divey; Hopkins, Gregory W; Seay, Sarah A; Chen, Ching-Ju; Perley, Casey C; Click, Eva M; Frothingham, Richard

2012-03-01

A murine low dose (LD) aerosol model is commonly used to test tuberculosis vaccines. Doses of 50-400 CFU (24h lung CFU) infect 100% of exposed mice. The LD model measures progression from infection to disease based on organ CFU at defined time points. To mimic natural exposure, we exposed mice to an ultra-low dose (ULD) aerosol. We estimated the presented dose by sampling the aerosol. Female C57BL/6 mice were exposed to Mycobacterium tuberculosis H37Rv aerosol at 1.0, 1.1, 1.6, 5.4, and 11 CFU presented dose, infecting 27%, 36%, 36%, 100%, and 95% of mice, respectively. These data are compatible with a stochastic infection event (Poisson distribution, weighted R(2)=0.97) or with a dose-response relationship (sigmoid distribution, weighted R(2)=0.97). Based on the later assumption, the ID50 was 1.6CFU presented dose (95% confidence interval, 1.2-2.1). We compared organ CFU after ULD and LD aerosols (5.4 vs. 395CFU presented dose). Lung burden was 30-fold lower in the ULD model at 4 weeks (3.4 vs. 4.8 logs, p<0.001) and 18 weeks (≤3.6 vs. 5.0 logs, p=0.01). Mice exposed to ULD aerosols as compared to LD aerosols had greater within-group CFU variability. Exposure to ULD aerosols leads to infection in a subset of mice, and to persistently low organ CFU. The ULD aerosol model may resemble human pulmonary tuberculosis more closely than the standard LD model, and may be used to identify host or bacterial factors that modulate the initial infection event. Copyright © 2011 Elsevier Ltd. All rights reserved.

Stressed (acute) mice display neuroimmunodysregulation and defective innate immune response against coliform infection.

PubMed

Mehrzad, Jalil; Shajari, Majid; Saleh-Moghaddam, Massoud; Sarmad-Nabavi, Mohammad

2015-09-01

We examined the impact of acute restraint stress (ARS) with(out) intraperitoneal E. coli infection on TLR4 mRNA abundance in brain and spleen, clinical signs, cytokines and oxidative loads and peritoneal E. coli growth in balb/c mice. ARS exacerbated E. coli virulence and behavioral abnormality. At different post-stress hour the pattern and intensity of TLR4 activity differed in brain and spleen. While TLR4 stimulation in spleen of E. coli-infected mice was maximal, it superseded in brain of post-stressed E. coli-infected mice. ARS and E. coli infection elicited systemic pro-inflammatory and pro-oxidant status, with defective peritoneal E. coli clearance in post-ARS mice. Continuous TLR4 activation in post-stressed mice partially disarms innate immune response, and contributes to inappropriate host-E. coli interactions and thus neuroimmune dysregulation/toxicity. The description of these observed novel effects induced by ARS will provide a basis for deeper investigations of the effects from increasingly stress-oriented rural/urban life upon neuroimmune system. Copyright © 2015 Elsevier B.V. All rights reserved.

Axl is not an indispensable factor for Zika virus infection in mice.

PubMed

Wang, Zhao-Yang; Wang, Zai; Zhen, Zi-Da; Feng, Kai-Hao; Guo, Jing; Gao, Na; Fan, Dong-Ying; Han, Dai-Shu; Wang, Pei-Gang; An, Jing

2017-08-01

Recently, Zika virus (ZIKV) outbreak has been associated with a sharp increase in cases of Guillain-Barré syndrome and severe fetal abnormalities. However, the mechanism underlying the interaction of ZIKV with host cells is not yet clear. Axl, a receptor tyrosine kinase, is postulated as a receptor for ZIKV entry; however, its in vivo role during ZIKV infection and its impact on the outcome of the disease have not been fully characterized and evaluated. Moreover, there are contradictory results on its involvement in ZIKV infection. Here we utilized Axl-deficient mice (Axl-/-) and their littermates (Axl+/-) to study the in vivo role of Axl in ZIKV infection. Our results showed that both Axl+/- and Axl-/- suckling mice supported the replication of ZIKV and presented clinical manifestations. No significant difference has been found between Axl-deficient mice and their littermates in terms of the survival rate, clinical manifestations, viral load, ZIKV distribution and histopathological changes in major organs. These results therefore indicate that Axl is not an indispensable factor for ZIKV infection in mice.

T cells establish and maintain CNS viral infection in HIV-infected humanized mice.

PubMed

Honeycutt, Jenna B; Liao, Baolin; Nixon, Christopher C; Cleary, Rachel A; Thayer, William O; Birath, Shayla L; Swanson, Michael D; Sheridan, Patricia; Zakharova, Oksana; Prince, Francesca; Kuruc, JoAnn; Gay, Cynthia L; Evans, Chris; Eron, Joseph J; Wahl, Angela; Garcia, J Victor

2018-06-04

The human brain is an important site of HIV replication and persistence during antiretroviral therapy (ART). Direct evaluation of HIV infection in the brains of otherwise healthy individuals is not feasible; therefore, we performed a large-scale study of bone marrow/liver/thymus (BLT) humanized mice as an in vivo model to study HIV infection in the brain. Human immune cells, including CD4+ T cells and macrophages, were present throughout the BLT mouse brain. HIV DNA, HIV RNA, and/or p24+ cells were observed in the brains of HIV-infected animals, regardless of the HIV isolate used. HIV infection resulted in decreased numbers of CD4+ T cells, increased numbers of CD8+ T cells, and a decreased CD4+/CD8+ T cell ratio in the brain. Using humanized T cell-only mice (ToM), we demonstrated that T cells establish and maintain HIV infection of the brain in the complete absence of human myeloid cells. HIV infection of ToM resulted in CD4+ T cell depletion and a reduced CD4+/CD8+ T cell ratio. ART significantly reduced HIV levels in the BLT mouse brain, and the immune cell populations present were indistinguishable from those of uninfected controls, which demonstrated the effectiveness of ART in controlling HIV replication in the CNS and returning cellular homeostasis to a pre-HIV state.

Aging aggravates ischemic stroke-induced brain damage in mice with chronic peripheral infection.

PubMed

Dhungana, Hiramani; Malm, Tarja; Denes, Adam; Valonen, Piia; Wojciechowski, Sara; Magga, Johanna; Savchenko, Ekaterina; Humphreys, Neil; Grencis, Richard; Rothwell, Nancy; Koistinaho, Jari

2013-10-01

Ischemic stroke is confounded by conditions such as atherosclerosis, diabetes, and infection, all of which alter peripheral inflammatory processes with concomitant impact on stroke outcome. The majority of the stroke patients are elderly, but the impact of interactions between aging and inflammation on stroke remains unknown. We thus investigated the influence of age on the outcome of stroke in animals predisposed to systemic chronic infection. Th1-polarized chronic systemic infection was induced in 18-22 month and 4-month-old C57BL/6j mice by administration of Trichuris muris (gut parasite). One month after infection, mice underwent permanent middle cerebral artery occlusion and infarct size, brain gliosis, and brain and plasma cytokine profiles were analyzed. Chronic infection increased the infarct size in aged but not in young mice at 24 h. Aged, ischemic mice showed altered plasma and brain cytokine responses, while the lesion size correlated with plasma prestroke levels of RANTES. Moreover, the old, infected mice exhibited significantly increased neutrophil recruitment and upregulation of both plasma interleukin-17α and tumor necrosis factor-α levels. Neither age nor infection status alone or in combination altered the ischemia-induced brain microgliosis. Our results show that chronic peripheral infection in aged animals renders the brain more vulnerable to ischemic insults, possibly by increasing the invasion of neutrophils and altering the inflammation status in the blood and brain. Understanding the interactions between age and infections is crucial for developing a better therapeutic regimen for ischemic stroke and when modeling it as a disease of the elderly. © 2013 The Anatomical Society and John Wiley & Sons Ltd.

[TLR-4 involvement in pyroptosis of mice with pulmonary inflammation infected by Actinobacillus pleuropneumoniae].

PubMed

Hu, Peipei; Huang, Fushen; Niu, Junchao; Tang, Zhaoshan

2015-05-04

Pyroptosis is a caspase-1 dependent programmed cell death and involves pathogenesis of infectious diseases by releasing many pro-inflammatory cytokines to induced inflammation. TLR-4 plays an important role in mediating pathogenesis of some infectious diseases. In this study, we detected the expression of TLR-4 and some molecules (e. g caspase-1, TNF-α, IL-1β, IL-6, IL-18 ) related with pyroptosis to determine its involvement and mechanisms of pulmonary inflammation in mice infected by A. pleuropneumoniae. Mice were intranasally infected by A. pleuropneumoniae and killed 48 hours post infection. Pulmonary gross lesion and histological pathology by H-E were observed. Expression levels of caspase-1 , caspase-3, TNF-α, IL-1β, IL-6, IL-18, and TLR-4 in lung of mice were detected by RT-PCR and qPCR. Serious pulmonary hemorrhage and inflammation in infected mice were observed. Expression levels of caspase-1, caspase-3, TNF-α, IL-1β, IL-6, IL-18 and TLR-4 increased, and expression levels of caspase-3 were not changed in lung of infected mice. TLR-4 might be involved in pulmonary inflammation of mice infected by A. pleuropneumoniae. After induced by activated TLR-4 some cells in this lesion expressed pro-inflammatory cytokines. These cytokines would induce pulmonary inflammation. This lesion might involve pyroptosis with caspase-1 expression.

Sex differences in colonization of gut microbiota from a man with short-term vegetarian and inulin-supplemented diet in germ-free mice.

PubMed

Wang, Jing-Jing; Wang, Jing; Pang, Xiao-Yan; Zhao, Li-Ping; Tian, Ling; Wang, Xing-Peng

2016-10-31

Gnotobiotic mouse model is generally used to evaluate the efficacy of gut microbiota. Sex differences of gut microbiota are acknowledged, yet the effect of recipient's gender on the bacterial colonization remains unclear. Here we inoculated male and female germ-free C57BL/6J mice with fecal bacteria from a man with short-term vegetarian and inulin-supplemented diet. We sequenced bacterial 16S rRNA genes V3-V4 region from donor's feces and recipient's colonic content. Shannon diversity index showed female recipients have higher bacteria diversity than males. Weighted UniFrac principal coordinates analysis revealed the overall structures of male recipient's gut microbiota were significantly separated from those of females, and closer to the donor. Redundancy analysis identified 46 operational taxonomic units (OTUs) differed between the sexes. The relative abundance of 13 OTUs were higher in males, such as Parabacteroides distasonis and Blautia faecis, while 33 OTUs were overrepresented in females, including Clostridium groups and Escherichia fergusonii/Shigella sonnei. Moreover, the interactions of these differential OTUs were sexually distinct. These findings demonstrated that the intestine of male and female mice preferred to accommodate microbiota differently. Therefore, it is necessary to designate the gender of gnotobiotic mice for complete evaluation of modulatory effects of gut microbiota from human feces upon diseases.

Correlation of Increased Metabolic Activity, Resistance to Infection, Enhanced Phagocytosis, and Inhibition of Bacterial Growth by Macrophages from Listeria- and BCG-Infected Mice

PubMed Central

Ratzan, Kenneth R.; Musher, Daniel M.; Keusch, Gerald T.; Weinstein, Louis

1972-01-01

Macrophages from mice infected with facultative intracellular organisms such as Listeria monocytogenes and BCG have been shown to resist infection by antigenically unrelated intracellular bacterial parasites. This study compares phagocytosis, bacterial growth inhibition, and oxidation of glucose by macrophages from normal mice, mice infected with listeria or BCG, or mice immunized with killed listeria in incomplete Freund's adjuvant. Macrophages from listeria- and BCG-infected mice ingested more listeria; 67 and 57%, respectively, had three or more cell-associated bacteria versus 22% of controls (P < 0.001). Peritoneal macrophages from listeria- and BCG-infected animals significantly (P < 0.001 covariance analysis) inhibited growth of listeria in suspension, whereas control macrophages had no such inhibitory effect. The rate of oxidation of glucose-1-14C was higher in macrophages from listeria- and BCG-infected mice than from either uninfected animals or those immunized with killed listeria. During phagocytosis of killed or live bacteria, or latex particles, the rate of glucose oxidation was increased (P < 0.01). These data suggest that the cellular immunity after infection by an intracellular organism is associated with an increase in metabolic activity of macrophages, namely, an increase in the rate of glucose oxidation resulting in enhancement of phagocytosis and killing. PMID:4629124

Efficacy of Gold Nanoparticles against Nephrotoxicity Induced by Schistosoma mansoni Infection in Mice.

PubMed

Dkhil, Mohamed A; Khalil, Mona F; Bauomy, Amira A; Diab, Marwa Sm; Al-Quraishy, Saleh

2016-11-01

In this study, the ameliorative effects of gold nanoparticles (gold NP) on the renal tissue damage in Schistosoma mansoni (S. mansoni)-infected mice was investigated. High-resolution transmission electron microscopy was used for the characterization of NP. The gold NP at concentrations of 250, 500, and 1000 μg/kg body weight were inoculated into S. mansoni-infected mice. The parasite caused alterations in the histological architecture. Furthermore, it induced a significant reduction in the renal glutathione levels; however, the levels of nitric oxide and malondialdehyde were significantly elevated. The parasite also managed to downregulate KIM-1, NGAL, MCP-1, and TGF-β mRNA expression in infected animals. Notably, gold NP treatment in mice reduced the extent of histological impairment and renal oxidative damage. Gold NP were able to regulate gene expression impaired by S. Mansoni infection. The curative effect of gold NP against renal toxicity in S. mansoni-infected mice is associated with their role as free radical scavengers. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Severe Leukopenia and Dysregulated Erythropoiesis in SCID Mice Persistently Infected with the Parvovirus Minute Virus of Mice

PubMed Central

Segovia, José C.; Gallego, Jesús M.; Bueren, Juan A.; Almendral, José M.

1999-01-01

Parvovirus minute virus of mice strain i (MVMi) infects committed granulocyte-macrophage CFU and erythroid burst-forming unit (CFU-GM and BFU-E, respectively) and pluripotent (CFU-S) mouse hematopoietic progenitors in vitro. To study the effects of MVMi infection on mouse hemopoiesis in the absence of a specific immune response, adult SCID mice were inoculated by the natural intranasal route of infection and monitored for hematopoietic and viral multiplication parameters. Infected animals developed a very severe viral-dose-dependent leukopenia by 30 days postinfection (d.p.i.) that led to death within 100 days, even though the number of circulating platelets and erythrocytes remained unaltered throughout the disease. In the bone marrow of every lethally inoculated mouse, a deep suppression of CFU-GM and BFU-E clonogenic progenitors occurring during the 20- to 35-d.p.i. interval corresponded with the maximal MVMi production, as determined by the accumulation of virus DNA replicative intermediates and the yield of infectious virus. Viral productive infection was limited to a small subset of primitive cells expressing the major replicative viral antigen (NS-1 protein), the numbers of which declined with the disease. However, the infection induced a sharp and lasting unbalance of the marrow hemopoiesis, denoted by a marked depletion of granulomacrophagic cells (GR-1+ and MAC-1+) concomitant with a twofold absolute increase in erythroid cells (TER-119+). A stimulated definitive erythropoiesis in the infected mice was further evidenced by a 12-fold increase per femur of recognizable proerythroblasts, a quantitative apoptosis confined to uninfected TER-119+ cells, as well as by a 4-fold elevation in the number of circulating reticulocytes. Therefore, MVMi targets and suppresses primitive hemopoietic progenitors leading to a very severe leukopenia, but compensatory mechanisms are mounted specifically by the erythroid lineage that maintain an effective erythropoiesis. The

Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

PubMed Central

Liu, Hsien Yueh; Chung, Chih-Yao; Yang, Wen-Chin; Liang, Chih-Lung; Wang, Chi-Young; Chang, Chih-Yu

2012-01-01

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macrophage populations with higher lipid content and lower phagocytic activity were observed. Exendin-4 lowered high lipid levels and enhanced phagocytosis in macrophages from db/db mice infected with L. monocytogenes. Exendin-4 also ameliorated obesity and hyperglycemia, and improved ex vivo bacteria clearance by macrophages in the animals. Liver histology examined during L. monocytogenes infection indicated that abscess formation was much milder in exendin-4-treated db/db mice than in the control animals. Moreover, mechanistic studies demonstrated that expression of ATP binding cassette transporter 1, a sterol transporter, was higher in macrophages isolated from the exendin-4-treated db/db mice. Overall, our results suggest that exendin-4 decreases the risk of infection in diabetic animals by modifying the interaction between intracellular lipids and phagocytic macrophages. PMID:23000581

Prebiotic inulin supplementation modulates the immune response and restores gut morphology in Giardia duodenalis-infected malnourished mice.

PubMed

Shukla, Geeta; Bhatia, Ruchika; Sharma, Anuj

2016-11-01

Malnutrition induces a state of growth retardation and immunologic depression, enhancing the host susceptibility to various infections. In the present study, it was observed that prebiotic supplementation either prior or simultaneously with Giardia infection in malnourished mice significantly reduced the severity of giardiasis and increased the body and small intestine mass, along with increased lactobacilli counts in faeces compared with malnourished-Giardia-infected mice. More specifically, prebiotic supplementation significantly increased the levels of anti-giardial IgG and IgA antibodies and anti-inflammatory cytokines IL-6 and IL-10 and reduced the pro-inflammatory cytokine TNF-α, along with increased levels of nitric oxide in both the serum and intestinal fluid of malnourished-prebiotic-Giardia-infected mice compared with malnourished-Giardia-infected mice. Histopathology and scanning electron microscopy of the small intestine also revealed less cellular and mucosal damage in the microvilli of prebiotic-supplemented malnourished-Giardia-infected mice compared with severely damaged mummified and blunted villi of malnourished-Giardia-infected mice. This is the first study to report that prebiotic supplementation modulated the gut morphology and improved the immune status even in malnourished-Giardia-infected mice.

Protection of mice deficient in mature B cells from West Nile virus infection by passive and active immunization

PubMed Central

Draves, Kevin E.; Young, Lucy B.; Bryan, Marianne A.; Dresch, Christiane; Diamond, Michael S.; Gale, Michael

2017-01-01

B cell activating factor receptor (BAFFR)-/- mice have a profound reduction in mature B cells, but unlike μMT mice, they have normal numbers of newly formed, immature B cells. Using a West Nile virus (WNV) challenge model that requires antibodies (Abs) for protection, we found that unlike wild-type (WT) mice, BAFFR-/- mice were highly susceptible to WNV and succumbed to infection within 8 to 12 days after subcutaneous virus challenge. Although mature B cells were required to protect against lethal infection, infected BAFFR-/- mice had reduced WNV E-specific IgG responses and neutralizing Abs. Passive transfer of immune sera from previously infected WT mice rescued BAFFR-/- and fully B cell-deficient μMT mice, but unlike μMT mice that died around 30 days post-infection, BAFFR-/- mice survived, developed WNV-specific IgG Abs and overcame a second WNV challenge. Remarkably, protective immunity could be induced in mature B cell-deficient mice. Administration of a WNV E-anti-CD180 conjugate vaccine 30 days prior to WNV infection induced Ab responses that protected against lethal infection in BAFFR-/- mice but not in μMT mice. Thus, the immature B cells present in BAFFR-/- and not μMT mice contribute to protective antiviral immunity. A CD180-based vaccine may promote immunity in immunocompromised individuals. PMID:29176765

Experimental Helicobacter marmotae infection in A/J mice causes enterohepatic disease

PubMed Central

Patterson, Mary M.; Rogers, Arlin B.; Fox, James G.

2010-01-01

Helicobacter marmotae has been identified in the inflamed livers of Eastern woodchucks (Marmota monax) infected with woodchuck hepatitis virus (WHV), as well as from the livers of WHV-negative woodchucks. Because the majority of WHV-positive woodchucks with hepatic tumours were culture or PCR positive for this helicobacter, and WHV-negative woodchucks with H. marmotae had hepatitis, the bacterium may have a role in tumour promotion related to chronic inflammation. In this study, the type strain of H. marmotae was inoculated intraperitoneally into 48 male and female A/J mice, a strain noted to be susceptible to Helicobacter hepaticus-induced liver tumours. Sixteen mice served as mock-dosed controls. At 6, 12 and 18 months post-inoculation (p.i.), there were statistically significant (P<0.05) differences in mean inflammation scores for the caecum and proximal colon between experimentally infected and control mice. Differences in hepatic inflammation were significant (P<0.05) at 6 and 12 months p.i. between the two groups but not at the 18 month time point. Two infected male mice had livers with severe hepatitis, and the liver samples were culture positive for H. marmotae. Serum IgG levels in the mice dosed with H. marmotae were elevated for the duration of the study. These results demonstrate that the woodchuck helicobacter can successfully colonize mice and cause enterohepatic disease. In the future, a mouse-adapted strain of H. marmotae could be selected to maximize colonization and lesion development. Such a woodchuck helicobacter-infected mouse model could be used to dissect potential mechanisms of microbial co-carcinogenesis involved in tumour development in woodchucks with WHV and in humans with hepatitis B virus. PMID:20616187

Intra-uterine experimental infection by Ureaplasma diversum induces TNF-α mediated womb inflammation in mice.

PubMed

Silva, Jamile R; Ferreira, Lício F A A; Oliveira, Percíllia V S; Nunes, Ivanéia V; Pereira, Ítalo S; Timenetsky, Jorge; Marques, Lucas M; Figueiredo, Tiana B; Silva, Robson A A

2016-01-01

Ureaplasma diversum is an opportunistic pathogen associated with uterine inflammation, impaired embryo implantation, infertility, abortions, premature birth of calves and neonatal pneumonia in cattle. It has been suggested that the intra-uterine infection by Ureaplasma diversum can cause vascular changes that hinder the success of pregnancy. Thus, the aim of this study was to evaluate the changes of intrauterine site of A/J mice in estrus or proestrus phase inoculated with Ureaplasma diversum. The infection was monitored at 24, 48 and 72 hours by the PCR methodology to detect the Ureaplasma in the inoculation site and the profile of circulating blood cells. Morphological changes, intensity of inflammation and the production of cytokines were compared. The infected mice showed local inflammation through the production of IFN-γ and TNF-α. Ureaplasma diversum infections in the reproductive tract of studied mice seemed to be associated with the production of pro-inflammatory cytokines in uterine parenchyma. The levels of TNF-α of infected mice were dependent on the bacterial load of inoculated Ureaplasma. Uterine experimental infections by Ureaplasma diversum have not been mentioned yet and herein we presented the first report of an intrauterine infection model in mice.

Hippocampal protection in mice with an attenuated inflammatory monocyte response to acute CNS picornavirus infection

PubMed Central

Howe, Charles L.; LaFrance-Corey, Reghann G.; Sundsbak, Rhianna S.; Sauer, Brian M.; LaFrance, Stephanie J.; Buenz, Eric J.; Schmalstieg, William F.

2012-01-01

Neuronal injury during acute viral infection of the brain is associated with the development of persistent cognitive deficits and seizures in humans. In C57BL/6 mice acutely infected with the Theiler's murine encephalomyelitis virus, hippocampal CA1 neurons are injured by a rapid innate immune response, resulting in profound memory deficits. In contrast, infected SJL and B6xSJL F1 hybrid mice exhibit essentially complete hippocampal and memory preservation. Analysis of brain-infiltrating leukocytes revealed that SJL mice mount a sharply attenuated inflammatory monocyte response as compared to B6 mice. Bone marrow transplantation experiments isolated the attenuation to the SJL immune system. Adoptive transfer of B6 inflammatory monocytes into acutely infected B6xSJL hosts converted these mice to a hippocampal damage phenotype and induced a cognitive deficit marked by failure to recognize a novel object. These findings show that inflammatory monocytes are the critical cellular mediator of hippocampal injury during acute picornavirus infection of the brain. PMID:22848791

Evaluation of Nitrofurantoin Combination Therapy of Metronidazole-Sensitive and -Resistant Helicobacter pylori Infections in Mice

PubMed Central

Jenks, Peter J.; Ferrero, Richard L.; Tankovic, Jacques; Thiberge, Jean-Michel; Labigne, Agnès

2000-01-01

The main objectives of this study were to determine whether the nitroreductase enzyme encoded by the rdxA gene of Helicobacter pylori was responsible for reductive activation of nitrofurantoin and whether a triple-therapy regimen with nitrofurantoin was able to eradicate metronidazole-sensitive and -resistant H. pylori infections from mice. The susceptibilities to nitrofurantoin of parent and isogenic rdxA mutant strains (three pairs), as well as a series of matched metronidazole-sensitive and -resistant strains isolated from mice (30) and patients (20), were assessed by agar dilution determination of the MIC. Groups of mice colonized with the metronidazole-sensitive H. pylori SS1 strain or a metronidazole-resistant rdxA SS1 mutant were treated with either metronidazole or nitrofurantoin as part of a triple-therapy regimen. One month after the completion of treatment the mice were sacrificed and their stomachs were cultured for H. pylori. The nitrofurantoin MICs for all strains tested were between 0.5 and 4.0 μg/ml. There was no significant difference between the susceptibility to nitrofurantoin of the parental strains and those of respective rdxA mutants or between those of matched metronidazole-sensitive and -resistant H. pylori isolates. The regimen with metronidazole eradicated infection from all eight SS1-infected mice and from one of eight mice inoculated with the rdxA mutant (P ≤ 0.001). The regimen with nitrofurantoin failed to eradicate infection from any of the six SS1-infected mice (P ≤ 0.001) and cleared infection from one of seven mice inoculated with the rdxA mutant. These results demonstrate that, despite the good in vitro activity of nitrofurantoin against H. pylori and the lack of cross-resistance between metronidazole and nitrofurantoin, eradication regimens involving nitrofurantoin are unable to eradicate either metronidazole-sensitive or -resistant H. pylori infections from mice. PMID:10991835

THE EFFECT OF NUTRITIONAL DISTURBANCES ON THE SUSCEPTIBILITY OF MICE TO STAPHYLOCOCCAL INFECTIONS

PubMed Central

Smiths, J. Maclean; Dubos, René J.

1956-01-01

The susceptibility of mice to intravenous injection of coagulase-positive hemolytic staphylococci was estimated by (a) observing the extent and time of mortality of infected animals; (b) determining the number of colonies of cocci that could be recovered from the liver and spleen at various intervals of time after infection. Complete deprival of food for 36 to 48 hours immediately before infection was found to increase susceptibility. This infection-enhancing effect was further increased by allowing the animals to drink a 5 per cent glucose solution instead of water or saline during the fasting period. In contrast, sodium lactate partially corrected the effect of fasting. The infection-enhancing effect of fasting was reversible. Mice prevented from gaining weight for several weeks either by restricting their daily food intake, or by feeding them ad lib. an inadequate diet, appeared just as resistant to staphylococcal infection as did mice that gained weight rapidly on an unrestricted, complete diet. PMID:13278458

Zika virus infection in immunocompetent pregnant mice causes fetal damage and placental pathology in the absence of fetal infection

PubMed Central

Kummer, Lawrence W.; Lanthier, Paula; Kim, In-Jeong; Kuki, Atsuo; Thomas, Stephen J.

2018-01-01

Zika virus (ZIKV) infection during human pregnancy may cause diverse and serious congenital defects in the developing fetus. Previous efforts to generate animal models of human ZIKV infection and clinical symptoms often involved manipulating mice to impair their Type I interferon (IFN) signaling, thereby allowing enhanced infection and vertical transmission of virus to the embryo. Here, we show that even pregnant mice competent to generate Type I IFN responses that can limit ZIKV infection nonetheless develop profound placental pathology and high frequency of fetal demise. We consistently found that maternal ZIKV exposure led to placental pathology and that ZIKV RNA levels measured in maternal, placental or embryonic tissues were not predictive of the pathological effects seen in the embryos. Placental pathology included trophoblast hyperplasia in the labyrinth, trophoblast giant cell necrosis in the junctional zone, and loss of embryonic vessels. Our findings suggest that, in this context of limited infection, placental pathology rather than embryonic/fetal viral infection may be a stronger contributor to adverse pregnancy outcomes in mice. Our finding demonstrates that in immunocompetent mice, direct viral infection of the embryo is not essential for fetal demise. Our immunologically unmanipulated pregnancy mouse model provides a consistent and easily measurable congenital abnormality readout to assess fetal outcome, and may serve as an additional model to test prophylactic and therapeutic interventions to protect the fetus during pregnancy, and for studying the mechanisms of ZIKV congenital immunopathogenesis. PMID:29634758

Acute ileitis facilitates infection with multidrug resistant Pseudomonas aeruginosa in human microbiota-associated mice.

PubMed

von Klitzing, Eliane; Ekmekciu, Ira; Bereswill, Stefan; Heimesaat, Markus M

2017-01-01

The rising incidence of multidrug resistant (MDR) Gram-negative bacteria including Pseudomonas aeruginosa has become a serious issue in prevention of its spread particularly among hospitalized patients. It is, however, unclear whether distinct conditions such as acute intestinal inflammation facilitate P. aeruginosa infection of vertebrate hosts. To address this, we analysed P. aeruginosa infection in human microbiota-associated (hma) mice with acute ileitis induced by peroral Toxoplasma gondii challenge. When perorally infected with P. aeruginosa at day 3 post ileitis induction, hma mice displayed higher intestinal P. aeruginosa loads as compared to hma mice without ileitis. However, the overall intestinal microbiota composition was not disturbed by P. aeruginosa (except for lowered bifidobacterial populations), and the infection did not further enhance ileal immune cell responses. Pro-inflammatory cytokines including IFN-γ and IL-12p70 were similarly increased in ileum and mesenteric lymph nodes of P. aeruginosa infected and uninfected hma mice with ileitis. The anti-inflammatory cytokine IL-10 increased multifold upon ileitis induction, but interestingly more distinctly in P. aeruginosa infected as compared to uninfected controls. Immune responses were not restricted to the intestines as indicated by elevated pro-inflammatory cytokine levels in liver and kidney upon ileitis induction. However, except for hepatic TNF-α levels, P. aeruginosa infection did not result in more distinct pro-inflammatory cytokine secretion in liver and kidney of hma mice with ileitis. Whereas viable intestinal bacteria were more frequently detected in systemic compartments such as spleen and cardiac blood of P. aeruginosa infected than uninfected mice at day 7 following ileitis induction, P. aeruginosa infection did not exacerbate systemic pro-inflammatory sequelae, but resulted in lower IL-10 serum levels. Acute intestinal inflammation facilitates infection of the vertebrate host

Critical Role of Airway Macrophages in Modulating Disease Severity during Influenza Virus Infection of Mice ▿

PubMed Central

Tate, Michelle D.; Pickett, Danielle L.; van Rooijen, Nico; Brooks, Andrew G.; Reading, Patrick C.

2010-01-01

Airway macrophages provide a first line of host defense against a range of airborne pathogens, including influenza virus. In this study, we show that influenza viruses differ markedly in their abilities to infect murine macrophages in vitro and that infection of macrophages is nonproductive and no infectious virus is released. Virus strain BJx109 (H3N2) infected macrophages with high efficiency and was associated with mild disease following intranasal infection of mice. In contrast, virus strain PR8 (H1N1) was poor in its ability to infect macrophages and highly virulent for mice. Depletion of airway macrophages by clodronate-loaded liposomes led to the development of severe viral pneumonia in BJx109-infected mice but did not modulate disease severity in PR8-infected mice. The severe disease observed in macrophage-depleted mice infected with BJx109 was associated with exacerbated virus replication in the airways, leading to severe airway inflammation, pulmonary edema, and vascular leakage, indicative of lung injury. Thymic atrophy, lymphopenia, and dysregulated cytokine and chemokine production were additional systemic manifestations associated with severe disease. Thus, airway macrophages play a critical role in limiting lung injury and associated disease caused by BJx109. Furthermore, the inability of PR8 to infect airway macrophages may be a critical factor contributing to its virulence for mice. PMID:20504924

Acute HBV infection in humanized chimeric mice has multiphasic viral kinetics

DOE PAGES

Ishida, Yuji; Chung, Tje Lin; Imamura, Michio; ...

2018-03-23

Background: Chimeric uPA/SCID mice reconstituted with humanized livers are useful for studying HBV infection in the absence of an adaptive immune response. However, the detailed characterization of HBV infection kinetics necessary to enable in-depth mechanistic studies in this novel in vivo HBV infection model is lacking. Methods: To characterize HBV kinetics post-inoculation (p.i.) to steady state, 42 mice were inoculated with HBV. Serum HBV DNA was frequently measured from 1 minute to 63 days p.i. Total intrahepatic HBV DNA, HBV cccDNA, and HBV RNA was measured in a subset of mice at 2, 4, 6, 10, and 13 weeks p.i.more » HBV half-life (t 1/2) was estimated using a linear mixed-effects model. Results: During the first 6 h p.i. serum HBV declined in repopulated uPA/SCID mice with a t 1/2=62 min [95%CI=59-67min]. Thereafter, viral decline slowed followed by a 2 day lower plateau. Subsequent viral amplification was multiphasic with an initial mean doubling time of t 2= 8±3 h followed by an interim plateau before prolonged amplification (t 2=2±0.5 days) to a final HBV steady state of 9.3 ± 0.3 log copies/ml. Serum HBV and intrahepatic HBV DNA were positively correlated (R2=0.98). Conclusions: HBV infection in uPA/SCID chimeric mice is highly dynamic despite the absence of an adaptive immune response. The serum HBV t 1/2 in humanized uPA/SCID mice was estimated to be ~1 h regardless of inoculum size. Finally, the HBV acute infection kinetics presented here is an important step in characterizing this experimental model system so that it can be effectively used to elucidate the dynamics of the HBV lifecycle and thus possibly reveal effective antiviral drug targets.« less

Acute HBV infection in humanized chimeric mice has multiphasic viral kinetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishida, Yuji; Chung, Tje Lin; Imamura, Michio

Background: Chimeric uPA/SCID mice reconstituted with humanized livers are useful for studying HBV infection in the absence of an adaptive immune response. However, the detailed characterization of HBV infection kinetics necessary to enable in-depth mechanistic studies in this novel in vivo HBV infection model is lacking. Methods: To characterize HBV kinetics post-inoculation (p.i.) to steady state, 42 mice were inoculated with HBV. Serum HBV DNA was frequently measured from 1 minute to 63 days p.i. Total intrahepatic HBV DNA, HBV cccDNA, and HBV RNA was measured in a subset of mice at 2, 4, 6, 10, and 13 weeks p.i.more » HBV half-life (t 1/2) was estimated using a linear mixed-effects model. Results: During the first 6 h p.i. serum HBV declined in repopulated uPA/SCID mice with a t 1/2=62 min [95%CI=59-67min]. Thereafter, viral decline slowed followed by a 2 day lower plateau. Subsequent viral amplification was multiphasic with an initial mean doubling time of t 2= 8±3 h followed by an interim plateau before prolonged amplification (t 2=2±0.5 days) to a final HBV steady state of 9.3 ± 0.3 log copies/ml. Serum HBV and intrahepatic HBV DNA were positively correlated (R2=0.98). Conclusions: HBV infection in uPA/SCID chimeric mice is highly dynamic despite the absence of an adaptive immune response. The serum HBV t 1/2 in humanized uPA/SCID mice was estimated to be ~1 h regardless of inoculum size. Finally, the HBV acute infection kinetics presented here is an important step in characterizing this experimental model system so that it can be effectively used to elucidate the dynamics of the HBV lifecycle and thus possibly reveal effective antiviral drug targets.« less

Effect of age on susceptibility to Salmonella Typhimurium infection in C57BL/6 mice.

PubMed

Ren, Zhihong; Gay, Raina; Thomas, Adam; Pae, Munkyong; Wu, Dayong; Logsdon, Lauren; Mecsas, Joan; Meydani, Simin Nikbin

2009-12-01

Ageing is associated with a decline in immune function, which predisposes the elderly to a higher incidence of infections. Information on the mechanism of the age-related increase in susceptibility to Salmonella enterica serovar Typhimurium (S. Typhimurium) is limited. In particular, little is known regarding the involvement of the immune response in this age-related change. We employed streptomycin (Sm)-pretreated C57BL/6 mice to develop a mouse model that would demonstrate age-related differences in susceptibility and immune response to S. Typhimurium. In this model, old mice inoculated orally with doses of 3 x 10(8) or 1 x 10(6) c.f.u. S. Typhimurium had significantly greater S. Typhimurium colonization in the ileum, colon, Peyer's patches, spleen and liver than young mice. Old mice had significantly higher weight loss than young mice on days 1 and 2 post-infection. In response to S. Typhimurium infection, old mice failed to increase ex vivo production of IFN-gamma and TNF-alpha in the spleen and mesenteric lymph node cells to the same degree as observed in young mice; this was associated with their inability to maintain the presence of neutrophils and macrophages at a 'youthful' level. These results indicate that Sm-pretreated C57BL/6 old mice are more susceptible to S. Typhimurium infection than young mice, which might be due to impaired IFN-gamma and TNF-alpha production as well as a corresponding change in the number of neutrophils and macrophages in response to S. Typhimurium infection compared to young mice.

Role of Indigenous Lactobacilli in Gastrin-Mediated Acid Production in the Mouse Stomach ▿

PubMed Central

Takahashi, Hidenori; Nakano, Yasuhiro; Matsuoka, Takashi; Kumaki, Nobue; Asami, Yukio; Koga, Yasuhiro

2011-01-01

It is known that the stomach is colonized by indigenous lactobacilli in mice. The aim of this study was to examine the role of such lactobacilli in the development of the stomach. For a DNA microarray analysis, germ-free BALB/c mice were orally inoculated with 109 CFU lactobacilli, and their stomachs were excised after 10 days to extract RNA. As a result, lactobacillus-associated gnotobiotic mice showed dramatically decreased expression of the gastrin gene in comparison to germ-free mice. The mean of the log2 fold change in the gastrin gene was −4.3. Immunohistochemistry also demonstrated the number of gastrin-positive (gastrin+) cells to be significantly lower in the lactobacillus-associated gnotobiotic mice than in the germ-free mice. However, there was no significant difference in the number of somatostatin+ cells in these groups of mice. Consequently, gastric acid secretion also decreased in the mice colonized by lactobacilli. In addition, an increase in the expression of the genes related to muscle system development, such as nebulin and troponin genes, was observed in lactobacillus-associated mice. Moreover, infection of germ-free mice with Helicobacter pylori also showed the down- and upregulation of gastrin and muscle genes, respectively, in the stomach. These results thus suggested that indigenous lactobacilli in the stomach significantly affect the regulation of gastrin-mediated gastric acid secretion without affecting somatostatin secretion in mice, while H. pylori also exerts such an effect on the stomach. PMID:21803885

Dysfunction of mitochondrial dynamics in the brains of scrapie-infected mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Hong-Seok; Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060; Choi, Yeong-Gon

Highlights: • Mfn1 and Fis1 are significantly increased in the hippocampal region of the ME7 prion-infected brain, whereas Dlp1 is significantly decreased in the infected brain. • Dlp1 is significantly decreased in the cytosolic fraction of the hippocampus in the infected brain. • Neuronal mitochondria in the prion-infected brains are enlarged and swollen compared to those of control brains. • There are significantly fewer mitochondria in the ME7-infected brain compared to the number in control brain. - Abstract: Mitochondrial dysfunction is a common and prominent feature of many neurodegenerative diseases, including prion diseases; it is induced by oxidative stress inmore » scrapie-infected animal models. In previous studies, we found swelling and dysfunction of mitochondria in the brains of scrapie-infected mice compared to brains of controls, but the mechanisms underlying mitochondrial dysfunction remain unclear. To examine whether the dysregulation of mitochondrial proteins is related to the mitochondrial dysfunction associated with prion disease, we investigated the expression patterns of mitochondrial fusion and fission proteins in the brains of ME7 prion-infected mice. Immunoblot analysis revealed that Mfn1 was up-regulated in both whole brain and specific brain regions, including the cerebral cortex and hippocampus, of ME7-infected mice compared to controls. Additionally, expression levels of Fis1 and Mfn2 were elevated in the hippocampus and the striatum, respectively, of the ME7-infected brain. In contrast, Dlp1 expression was significantly reduced in the hippocampus in the ME7-infected brain, particularly in the cytosolic fraction. Finally, we observed abnormal mitochondrial enlargement and histopathological change in the hippocampus of the ME7-infected brain. These observations suggest that the mitochondrial dysfunction, which is presumably caused by the dysregulation of mitochondrial fusion and fission proteins, may contribute to the

Plasmodium berghei infection ameliorates atopic dermatitis-like skin lesions in NC/Nga mice.

PubMed

Kishi, C; Amano, H; Suzue, K; Ishikawa, O

2014-10-01

Atopic diseases are more prevalent in industrialized countries than in developing countries. In addition, significant differences in the prevalence of allergic diseases are observed between rural and urban areas within the same country. This difference in prevalence has been attributed to what is called the 'hygiene hypothesis'. Although parasitic infections are known to protect against allergic reactions, the mechanism is still unknown. The aim of this study was to investigate whether or not malarial infections can inhibit atopic dermatitis (AD)-like skin lesions in a mouse model of AD. We used NC/Nga mice which are a model for AD. The NC/Nga mice were intraperitoneally infected with 1 × 10(5) Plasmoduim berghei (Pb) XAT-infected erythrocytes. Malarial infections ameliorated AD-like skin lesions in the NC/Nga mice. This improvement was blocked by the administration of anti-asialo GM1 antibodies, which are anti-natural killer (NK) cells. Additionally, adoptive transfer of NK cells markedly improved AD-like skin lesions in conventional NC/Nga mice; these suggest that the novel protective mechanism associated with malaria parasitic infections is at least, in part, dependent on NK cells. We have experimentally demonstrated for the first time that malarial infections ameliorated AD-like skin lesions in a mouse model of AD. Our study could explain in part the mechanism of the 'hygiene hypothesis', which states that parasitic infections can inhibit the development of allergic diseases. © 2014 The Authors. Allergy Published by John Wiley & Sons Ltd.

Experimental Andes virus infection in deer mice: characteristics of infection and clearance in a heterologous rodent host.

PubMed

Spengler, Jessica R; Haddock, Elaine; Gardner, Don; Hjelle, Brian; Feldmann, Heinz; Prescott, Joseph

2013-01-01

New World hantaviruses can cause hantavirus cardiopulmonary syndrome with high mortality in humans. Distinct virus species are hosted by specific rodent reservoirs, which also serve as the vectors. Although regional spillover has been documented, it is unknown whether rodent reservoirs are competent for infection by hantaviruses that are geographically separated, and known to have related, but distinct rodent reservoir hosts. We show that Andes virus (ANDV) of South America, carried by the long tailed pygmy rice rat (Oligoryzomys longicaudatus), infects and replicates in vitro and in vivo in the deer mouse (Peromyscus maniculatus), the reservoir host of Sin Nombre virus (SNV), found in North America. In experimentally infected deer mice, viral RNA was detected in the blood, lung, heart and spleen, but virus was cleared by 56 days post inoculation (dpi). All of the inoculated deer mice mounted a humoral immune response by 14 dpi, and produced measurable amounts of neutralizing antibodies by 21 dpi. An up-regulation of Ccl3, Ccl4, Ccl5, and Tgfb, a strong CD4⁺ T-cell response, and down-regulation of Il17, Il21 and Il23 occurred during infection. Infection was transient with an absence of clinical signs or histopathological changes. This is the first evidence that ANDV asymptomatically infects, and is immunogenic in deer mice, a non-natural host species of ANDV. Comparing the immune response in this model to that of the immune response in the natural hosts upon infection with their co-adapted hantaviruses may help clarify the mechanisms governing persistent infection in the natural hosts of hantaviruses.

Course of induced infection by Eimeria krijgsmannni in immunocompetent and immunodeficient mice.

PubMed

Ono, Yuina; Matsubayashi, Makoto; Kawaguchi, Hiroaki; Tsujio, Masashi; Mizuno, Masanobu; Tanaka, Tetsuya; Masatani, Tatsunori; Matsui, Toshihiro; Matsuo, Tomohide

2016-01-01

Recently, we have demonstrated the utility of Eimeria krijgsmanni as a novel mouse eimerian parasite for elucidating the biological diversity. The parasite showed notable infectivity to mice with various levels of immune status and susceptibility to antimicrobial agents including coccidiostat. However, the detailed lifecycle of E. krijgsmanni had not yet been determined and this information was lacking in discussion of previous findings. In the present study, we clarified the morphological characteristics of E. krijgsmanni and its lifecycle in normal mice, and examined the effects in immunodeficient mice and lifecycle stage for challenge infections after the primary inoculation. In immunocompetent mice, the lifecycle consisted of four asexual stages and the sexual sages followed by formation of oocysts during the prepatent periods. Interestingly, the second-generation meronts were detected in all observation periods after the disappearance of the other stages. For the challenge infection of immunodeficient mice, all developmental stages except for the second generation meronts were temporarily vanished. This finding suggests a "rest" or marked delay in development and a "restart" of the promotion toward the next generations. The second generation meronts may play an important role in the lifecycle of E. krijgsmanni.

[Effect of perinatal recurrent infection on the brain development in immature mice].

PubMed

Song, Li-Li; Huang, Zhi-Heng; Pei, Yi-Ling; Chen, Chao

2014-12-01

To study the effects of perinatal recurrent infection on the brain development in immature mice. Six pregnant C57BL6 mice were randomly assigned to three groups: intrauterine infection, perinatal recurrent infection and control. The intrauterine infection group was intraperitoneally injected with LPS (0.5 mg/kg) on the 18th day of pregnancy. The perinatal recurrent infection group was injected with LPS (0.5 mg/kg) on the 18th day of pregnancy and their offsprings were intraperitoneally injected with the same dose of LPS daily from postnatal day 3 to 12. The control group was administered with normal saline at the same time points as the recurrent infection group. The short-time neurobehaviors were assessed on postnatal day 13. The mice were then sacrificed to measure brain weights and neuropathological changes using cresyl violet staining. Western blot was used to evaluate the expression of TNF-α, Caspase-3 and myelin basic protein (MBP). The brain weights of the recurrent infection group were significantly lower than the control and intrauterine infection groups (P<0.05) and the recurrent infection group displayed significant neuropathological changes. Perinatal recurrent infection resulted in increased expression levels of TNF-α and Caspase-3, and decreased expression level of MBP compared with the intrauterine infection and control groups (P<0.01). The neurobehavior test showed that the recurrent infection group used longer time in gait reflex, right reflex and geotaxis reflex compared with the control and intrauterine infection groups on postnatal day 13 (P<0.05). Perinatal recurrent infection may exacerbate inflammatory response and cell death in the immature brain, which may be one of the important factors for perinatal brain injury.

Roles of CD4+ T Cells and Gamma Interferon in Protective Immunity against Babesia microti Infection in Mice

PubMed Central

Igarashi, Ikuo; Suzuki, Reiko; Waki, Seiji; Tagawa, Yoh-Ichi; Seng, Seyha; Tum, Sothyra; Omata, Yoshitaka; Saito, Atsushi; Nagasawa, Hideyuki; Iwakura, Yohichiro; Suzuki, Naoyoshi; Mikami, Takeshi; Toyoda, Yutaka

1999-01-01

Babesia microti produces a self-limiting infection in mice, and recovered mice are resistant to reinfection. In the present study, the role of T cells in protective immunity against challenge infection was examined. BALB/c mice which recovered from primary infection showed strong protective immunity against challenge infection. In contrast, nude mice which failed to control the primary infection and were cured with an antibabesial drug did not show protection against challenge infection. Treatment of immune mice with anti-CD4 monoclonal antibody (MAb) diminished the protective immunity against challenge infection, but treatment with anti-CD8 MAb had no effect on the protection. Transfer of CD4+ T-cell-depleted spleen cells resulted in higher parasitemia than transfer of CD8+ T-cell-depleted spleen cells. A high level of gamma interferon (IFN-γ), which was produced by CD4+ T cells, was observed for the culture supernatant of spleen cells from immune mice, and treatment of immune mice with anti-IFN-γ MAb partially reduced the protection. Moreover, no protection against challenge infection was found in IFN-γ-deficient mice. On the other hand, treatment of immune mice with MAbs against interleukin-2 (IL-2), IL-4, or tumor necrosis factor alpha did not affect protective immunity. These results suggest essential requirements for CD4+ T cells and IFN-γ in protective immunity against challenge infection with B. microti. PMID:10417185

Expression profiling of lymph node cells from deer mice infected with Andes virus.

PubMed

Schountz, Tony; Shaw, Timothy I; Glenn, Travis C; Feldmann, Heinz; Prescott, Joseph

2013-04-09

Deer mice (Peromyscus maniculatus) are the principal reservoir hosts of Sin Nombre virus (SNV), the cause of the great majority of hantavirus cardiopulmonary syndrome (HCPS) cases in North America. SNV, like all hantaviruses with their reservoirs, causes persistent infection without pathology in deer mice and appear to elicit a regulatory T cell response. Deer mice are also susceptible to Andes virus (ANDV), which causes the great majority of HCPS cases in South America, but they clear infection by 56 days post infection without signs of disease. We examined lymph node cell responses of deer mice infected with ANDV to determine expression profiles upon in vitro recall challenge with viral antigen. Because the deer mouse genome is currently unannotated, we developed a bioinformatics pipeline to use known lab mouse (Mus musculus) cDNAs to predict genes within the deer mouse genome and design primers for quantitative PCR (http://dna.publichealth.uga.edu/BlastPrimer/BlastPrimer.php). Of 94 genes examined, 20 were elevated, the plurality of which were Th2-specific, whereas 12 were downregulated. Other expressed genes represented Th1, regulatory T cells and follicular helper T cells, and B cells, but not Th17 cells, indicating that many cellular phenotypes participate in the host response to Andes virus. The ability to examine expression levels of nearly any gene from deer mice should allow direct comparison of infection with SNV or ANDV to determine the immunological pathways used for clearance of hantavirus infection in a reservoir host species.

Reduced infectivity of waterborne viable but nonculturable Helicobacter pylori strain SS1 in mice.

PubMed

Boehnke, Kevin F; Eaton, Kathryn A; Fontaine, Clinton; Brewster, Rebecca; Wu, Jianfeng; Eisenberg, Joseph N S; Valdivieso, Manuel; Baker, Laurence H; Xi, Chuanwu

2017-08-01

Helicobacter pylori infection has been consistently associated with lack of access to clean water and proper sanitation, but no studies have demonstrated that the transmission of viable but nonculturable (VBNC) H. pylori can occur from drinking contaminated water. In this study, we used a laboratory mouse model to test whether waterborne VBNCH. pylori could cause gastric infection. We performed five mouse experiments to assess the infectivity of VBNCH. pylori in various exposure scenarios. VBNC viability was examined using Live/Dead staining and Biolog phenotype metabolism arrays. High doses of VBNCH. pylori in water were chosen to test the "worst-case" scenario for different periods of time. One experiment also investigated the infectious capabilities of VBNC SS1 using gavage. Further, immunocompromised mice were exposed to examine infectivity among potentially vulnerable groups. After exposure, mice were euthanized and their stomachs were examined for H. pylori infection using culture and PCR methodology. VBNC cells were membrane intact and retained metabolic activity. Mice exposed to VBNCH. pylori via drinking water and gavage were not infected, despite the various exposure scenarios (immunocompromised, high doses) that might have permitted infection with VBNCH. pylori. The positive controls exposed to viable, culturable H. pylori did become infected. While other studies that have used viable, culturable SS1 via gavage or drinking water exposures to successfully infect mice, in our study, waterborne VBNC SS1 failed to colonize mice under all test conditions. Future studies could examine different H. pylori strains in similar exposure scenarios to compare the relative infectivity of the VBNC vs the viable, culturable state, which would help inform future risk assessments of H. pylori in water. © 2017 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

Differential Lymphocyte and Antibody Responses in Deer Mice Infected with Sin Nombre Hantavirus or Andes Hantavirus

PubMed Central

Quackenbush, Sandra; Rovnak, Joel; Haddock, Elaine; Black, William C.; Feldmann, Heinz; Prescott, Joseph

2014-01-01

ABSTRACT Hantavirus cardiopulmonary syndrome (HCPS) is a rodent-borne disease with a high case-fatality rate that is caused by several New World hantaviruses. Each pathogenic hantavirus is naturally hosted by a principal rodent species without conspicuous disease and infection is persistent, perhaps for life. Deer mice (Peromyscus maniculatus) are the natural reservoirs of Sin Nombre virus (SNV), the etiologic agent of most HCPS cases in North America. Deer mice remain infected despite a helper T cell response that leads to high-titer neutralizing antibodies. Deer mice are also susceptible to Andes hantavirus (ANDV), which causes most HCPS cases in South America; however, deer mice clear ANDV. We infected deer mice with SNV or ANDV to identify differences in host responses that might account for this differential outcome. SNV RNA levels were higher in the lungs but not different in the heart, spleen, or kidneys. Most ANDV-infected deer mice had seroconverted 14 days after inoculation, but none of the SNV-infected deer mice had. Examination of lymph node cell antigen recall responses identified elevated immune gene expression in deer mice infected with ANDV and suggested maturation toward a Th2 or T follicular helper phenotype in some ANDV-infected deer mice, including activation of the interleukin 4 (IL-4) pathway in T cells and B cells. These data suggest that the rate of maturation of the immune response is substantially higher and of greater magnitude during ANDV infection, and these differences may account for clearance of ANDV and persistence of SNV. IMPORTANCE Hantaviruses persistently infect their reservoir rodent hosts without pathology. It is unknown how these viruses evade sterilizing immune responses in the reservoirs. We have determined that infection of the deer mouse with its homologous hantavirus, Sin Nombre virus, results in low levels of immune gene expression in antigen-stimulated lymph node cells and a poor antibody response. However, infection

Differential lymphocyte and antibody responses in deer mice infected with Sin Nombre hantavirus or Andes hantavirus.

PubMed

Schountz, Tony; Quackenbush, Sandra; Rovnak, Joel; Haddock, Elaine; Black, William C; Feldmann, Heinz; Prescott, Joseph

2014-08-01

Hantavirus cardiopulmonary syndrome (HCPS) is a rodent-borne disease with a high case-fatality rate that is caused by several New World hantaviruses. Each pathogenic hantavirus is naturally hosted by a principal rodent species without conspicuous disease and infection is persistent, perhaps for life. Deer mice (Peromyscus maniculatus) are the natural reservoirs of Sin Nombre virus (SNV), the etiologic agent of most HCPS cases in North America. Deer mice remain infected despite a helper T cell response that leads to high-titer neutralizing antibodies. Deer mice are also susceptible to Andes hantavirus (ANDV), which causes most HCPS cases in South America; however, deer mice clear ANDV. We infected deer mice with SNV or ANDV to identify differences in host responses that might account for this differential outcome. SNV RNA levels were higher in the lungs but not different in the heart, spleen, or kidneys. Most ANDV-infected deer mice had seroconverted 14 days after inoculation, but none of the SNV-infected deer mice had. Examination of lymph node cell antigen recall responses identified elevated immune gene expression in deer mice infected with ANDV and suggested maturation toward a Th2 or T follicular helper phenotype in some ANDV-infected deer mice, including activation of the interleukin 4 (IL-4) pathway in T cells and B cells. These data suggest that the rate of maturation of the immune response is substantially higher and of greater magnitude during ANDV infection, and these differences may account for clearance of ANDV and persistence of SNV. Hantaviruses persistently infect their reservoir rodent hosts without pathology. It is unknown how these viruses evade sterilizing immune responses in the reservoirs. We have determined that infection of the deer mouse with its homologous hantavirus, Sin Nombre virus, results in low levels of immune gene expression in antigen-stimulated lymph node cells and a poor antibody response. However, infection of deer mice with a

Oxygen effects on mortality of mice infected with Diplococcus pneumoniae

NASA Technical Reports Server (NTRS)

Angrick, E. J.; Somerson, N. L.; Weiss, H. S.

1974-01-01

Mice infected by intraperitoneal injection of Diplococcus pneumoniae were held at 1 atm in either hypoxic (12%), hyperoxic (75%), or a normal (21%) oxygen environment. Mortality rates indicated prolongation of survival in hypoxia and shortened survival in hyperoxia. Exposure of mice to the experimental gas mixtures prior to inoculation did not alter the results.

Toxoplasma gondii Infection Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice.

PubMed

Jeong, Young Il; Hong, Sung Hee; Cho, Shin Hyeong; Lee, Won Ja; Lee, Sang Eun

2015-11-01

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects humans and animals via congenital or postnatal routes, and it is found worldwide. Modulation of the immune system by parasite infection is proposed to suppress allergic inflammation. Growing evidences have shown that interleukin (IL)-10-producing regulatory B cells (B(regs)) and CD4+CD25+FoxP3+ regulatory T cells (T(regs)) induced by parasite infection play a critical role in allergic or autoimmune diseases because these cells regulate negatively cellular immune responses and inflammation. Currently, the role of IL-10-producing regulatory B cells in host immune response during T. gondii infection is unknown. In this study, we investigate whether T. gondii infection can suppress the development of unrelated atopic dermatitis (AD)-like lesions. AD is a chronically relapsing inflammatory skin disease accompanied by severe itching; for this, we used NC/Nga mice, a well-known experimental model of systemic AD. Repeated exposure to Dermatophagoides farinae crude extract (DfE), known as a major environmental allergen, evokes AD-like skin lesions in NC/Nga mice under specific pathogen-free conditions. NC/Nga mice were intraperitoneally infected with 10 cysts of T. gondii. T. gondii infection significantly ameliorated AD-like skin lesions in NC/Nga mice. The subpopulation of B(regs) and T(regs) in the AD mice was expanded in the course of T. gondii infection. In addition, T. gondii infection inhibited Th2 and enhanced Th1 immune response in the DfE-treated AD mice. We have experimentally demonstrated for the first time that T. gondii infection ameliorated AD-like skin lesions in a mouse model of AD. Our study could in part explain the mechanisms of how parasite infection prevents the development of allergic disorder. Therefore, these immunemechanisms induced by T. gondii infection may be beneficial for the host in terms of reduced risk of allergic immune reactions.

Chronic Trichuris muris infection causes neoplastic change in the intestine and exacerbates tumour formation in APC min/+ mice

PubMed Central

Cliffe, Laura J.; Bancroft, Alison J.; Forman, Simon P.; Thompson, Seona; Booth, Cath

2017-01-01

Incidences of infection-related cancers are on the rise in developing countries where the prevalence of intestinal nematode worm infections are also high. Trichuris muris (T. muris) is a murine gut-dwelling nematode that is the direct model for human T. trichiura, one of the major soil-transmitted helminth infections of humans. In order to assess whether chronic infection with T. muris does indeed influence the development of cancer hallmarks, both wild type mice and colon cancer model (APC min/+) mice were infected with this parasite. Parasite infection in wild type mice led to the development of neoplastic change similar to that seen in mice that had been treated with the carcinogen azoxymethane. Additionally, both chronic and acute infection in the APCmin/+ mice led to an enhanced tumour development that was distinct to the site of infection suggesting systemic control. By blocking the parasite induced T regulatory response in these mice, the increase in the number of tumours following infection was abrogated. Thus T. muris infection alone causes an increase in gut pathologies that are known to be markers of cancer but also increases the incidence of tumour formation in a colon cancer model. The influence of parasitic worm infection on the development of cancer may therefore be significant. PMID:28650985

Chronic Trichuris muris infection causes neoplastic change in the intestine and exacerbates tumour formation in APC min/+ mice.

PubMed

Hayes, Kelly S; Cliffe, Laura J; Bancroft, Alison J; Forman, Simon P; Thompson, Seona; Booth, Cath; Grencis, Richard K

2017-06-01

Incidences of infection-related cancers are on the rise in developing countries where the prevalence of intestinal nematode worm infections are also high. Trichuris muris (T. muris) is a murine gut-dwelling nematode that is the direct model for human T. trichiura, one of the major soil-transmitted helminth infections of humans. In order to assess whether chronic infection with T. muris does indeed influence the development of cancer hallmarks, both wild type mice and colon cancer model (APC min/+) mice were infected with this parasite. Parasite infection in wild type mice led to the development of neoplastic change similar to that seen in mice that had been treated with the carcinogen azoxymethane. Additionally, both chronic and acute infection in the APCmin/+ mice led to an enhanced tumour development that was distinct to the site of infection suggesting systemic control. By blocking the parasite induced T regulatory response in these mice, the increase in the number of tumours following infection was abrogated. Thus T. muris infection alone causes an increase in gut pathologies that are known to be markers of cancer but also increases the incidence of tumour formation in a colon cancer model. The influence of parasitic worm infection on the development of cancer may therefore be significant.

Recognition of a 30,000 MW antigen of Giardia muris trophozoites by intestinal IgA from Giardia-infected mice.

PubMed

Heyworth, M F; Pappo, J

1990-08-01

The principal aims of this work were (i) to identify the molecular weight (MW) of Giardia muris trophozoite antigens that are recognized by IgA in small intestinal secretions from G. muris-infected mice, and (ii) to determine whether mouse intestinal Giardia-specific IgA is directed against trophozoite surfaces. BALB/c mice were infected with G. muris cysts, and intestinal secretions were harvested from these mice at various times after the start of Giardia infection, and from uninfected mice. Flow cytometry showed that intestinal IgA from G. muris-infected mice, but not from uninfected mice, became bound to trophozoite surfaces in vitro. Western blotting of trophozoite proteins with mouse intestinal secretions showed that IgA from Giardia-infected mice reacted specifically with a broad protein band of approximately 30,000 MW. This finding suggests that one or more trophozoite proteins of approximately 30,000 MW are targets for intestinal antibody in mice infected with G. muris.

Recognition of a 30,000 MW antigen of Giardia muris trophozoites by intestinal IgA from Giardia-infected mice.

PubMed Central

Heyworth, M F; Pappo, J

1990-01-01

The principal aims of this work were (i) to identify the molecular weight (MW) of Giardia muris trophozoite antigens that are recognized by IgA in small intestinal secretions from G. muris-infected mice, and (ii) to determine whether mouse intestinal Giardia-specific IgA is directed against trophozoite surfaces. BALB/c mice were infected with G. muris cysts, and intestinal secretions were harvested from these mice at various times after the start of Giardia infection, and from uninfected mice. Flow cytometry showed that intestinal IgA from G. muris-infected mice, but not from uninfected mice, became bound to trophozoite surfaces in vitro. Western blotting of trophozoite proteins with mouse intestinal secretions showed that IgA from Giardia-infected mice reacted specifically with a broad protein band of approximately 30,000 MW. This finding suggests that one or more trophozoite proteins of approximately 30,000 MW are targets for intestinal antibody in mice infected with G. muris. Images Figure 4 PMID:2394467

The influence of dual infection with herpes and influenza viruses on the differential blood cell count of mice.

PubMed

Ančicová, L; Dugovičová, V; Briestenská, K; Kostolanský, F; Varečková, E; Mistríková, J

Based on our previous results, which confirmed the role of latent gammaherpesvirus infection in alteration of immune homeostasis, we studied the influence of simultaneous infection with gammaherpes and influenza viruses on selected parameters of innate immunity, particularly on the subpopulations of peripheral blood cell leukocytes. The aim was to analyze changes of differential blood cell count of BALB/c mice persistently infected with murine gammaherpesvirus 68 (MHV-68) and subsequently co-infected with influenza A virus (IAV), in comparison to mice infected with MHV-68 or with IAV only. Our results showed that ongoing gammaherpesvirus latency in mice caused a decreased number of leukocytes after acute infection with IAV in comparison to a single acute IAV infection. However, increased proportion of neutrophils was measured in peripheral blood of IAV- infected and co-infected mice. Dual infection had no effect on the proportion of monocytes or basophilic and eosinophilic granulocytes. The number of atypical lymphocytes, usually accompanying the persistent infection with MHV-68, decreased in co-infected mice as a consequence of the acute infection with IAV. Persistent infection with gammaherpesvirus may thus modulate the host immune response to influenza A virus and the acute IAV infection can influence the immune homeostasis established by latent MHV-68 infection.

Impact of benznidazole on infection course in mice experimentally infected with Trypanosoma cruzi I, II, and IV.

PubMed

Gruendling, Ana Paula; Massago, Miyoko; Teston, Ana Paula M; Monteiro, Wuelton M; Kaneshima, Edilson N; Araújo, Silvana M; Gomes, Mônica L; Barbosa, Maria das Graças V; Toledo, Max Jean O

2015-06-01

American trypanosomiasis is an emerging zoonosis in the Brazilian Amazon. Studies on benznidazole (BZ) chemotherapy with Trypanosoma cruzi from this region have great relevance, given the different discrete typing units (DTUs) that infect humans in the Amazon and other regions of Brazil. We performed a parasitological, histopathological, and molecular analysis of mice inoculated with strains of T. cruzi I, II, and IV that were BZ-treated during the acute phase of infection. Groups of Swiss mice were inoculated; 13 received oral BZ, whereas the other 13 comprised the untreated controls. Unlike parasitemia, the infectivity and mortality did not vary among the DTUs. Trypanosoma cruzi DNA was detected in all tissues analyzed and the proportion of organs parasitized varied with the parasite DTU. The BZ treatment reduced the most parasitological parameters, tissue parasitism and the inflammatory processes at all infection stages and for all DTUs. However, the number of significant reductions varied according to the DTU and infection phase. © The American Society of Tropical Medicine and Hygiene.

Zika Virus Fatally Infects Wild Type Neonatal Mice and Replicates in Central Nervous System

PubMed Central

Armstrong, Najealicka; Zhao, Huan; Hou, Wangheng; Liu, Jian; Chen, Chunye; Wan, Junkai; Wang, Wei; Zhong, Chunlian; Liu, Che; Zhu, Hua; Xia, Ningshao; Cheng, Tong

2018-01-01

Zika virus (ZIKV) has been defined as a teratogenic pathogen behind the increased number of cases of microcephaly in French Polynesia, Brazil, Puerto Rico, and other South American countries. Experimental studies using animal models have achieved tremendous insight into understanding the viral pathogenesis, transmission, teratogenic mechanisms, and virus–host interactions. However, the animals used in published investigations are mostly interferon (IFN)-compromised, either genetically or via antibody treatment. Herein, we studied ZIKV infection in IFN-competent mice using African (MR766) and Asian strains (PRVABC59 and SZ-WIV01). After testing four different species of mice, we found that BALB/c neonatal mice were resistant to ZIKV infection, that Kunming, ICR and C57BL/6 neonatal mice were fatally susceptible to ZIKV infection, and that the fatality of C57BL/6 neonates from 1 to 3 days old were in a viral dose-dependent manner. The size and weight of the brain were significantly reduced, and the ZIKV-infected mice showed neuronal symptoms such as hind-limb paralysis, tremor, and poor balance during walking. Pathologic and immunofluorescent experiments revealed that ZIKV infected different areas of the central nervous system (CNS) including gray matter, hippocampus, cerebral cortex, and spinal cord, but not olfactory bulb. Interestingly, ZIKV replicated in multiple organs and resulted in pathogenesis in liver and testis, implying that ZIKV infection may engender a high health risk in neonates by postnatal infection. In summary, we investigated ZIKV pathogenesis using an animal model that is not IFN-compromised. PMID:29361773

Acute Brucella melitensis M16 infection model in mice treated with tumor necrosis factor-alpha inhibitors.

PubMed

Kutlu, Murat; Ergin, Çağrı; Şen-Türk, Nilay; Sayin-Kutlu, Selda; Zorbozan, Orçun; Akalın, Şerife; Şahin, Barboros; Çobankara, Veli; Demirkan, Neşe

2015-02-19

There is limited data in the literature about brucellosis related to an intracellular pathogen and anti-tumor necrosis factor alpha (anti-TNFα) medication. The aim of this study was to evaluate acute Brucella infections in mice receiving anti-TNFα drug treatment. Anti-TNFα drugs were injected in mice on the first and fifth days of the study, after which the mice were infected with B. melitensis M16 strain. Mice were sacrificed on the fourteenth day after infection. Bacterial loads in the liver and spleen were defined, and histopathological changes were evaluated. Neither the liver nor the spleen showed an increased bacterial load in all anti-TNFα drug groups when compared to a non-treated, infected group. The most significant histopathological findings were neutrophil infiltrations in the red pulp of the spleen and apoptotic cells with hepatocellular pleomorphism in the liver. There was no significant difference among the groups in terms of previously reported histopathological findings, such as extramedullary hematopoiesis and granuloma formation. There were no differences in hepatic and splenic bacterial load and granuloma formation, which indicate worsening of the acute Brucella infection in mice; in other words, anti-TNFα treatment did not exacerbate the acute Brucella spp. infection in mice.

The hepatoprotective activity of blue green algae in Schistosoma mansoni infected mice.

PubMed

Mohamed, Azza H; Osman, Gamalat Y; Salem, Tarek A; Elmalawany, Alshimaa M

2014-10-01

This study aims to evaluate the immunomodulatory effects of a natural product, blue green algae (BGA) (100 mg/kg BW), alone or combined with praziquantel PZQ (250 mg/kg BW) on granulomatous inflammation, liver histopathology, some biochemical and immunological parameters in mice infected with Schistosoma mansoni. Results showed that the diameter and number of egg granuloma were significantly reduced after treatment of S. mansoni-infected mice with BGA, PZQ and their combination. The histopathological alterations observed in the liver of S. mansoni-infected mice were remarkably inhibited after BGA treatments. BGA decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) as well as the level of total protein (TP) while the level of albumin was increased. Treatment of infected mice with BGA, PZQ as well as their combination led to significant elevation in the activities of hepatic antioxidant enzymes glutathione peroxidase (GPX) and glutathione-S-transferase (GST) as compared with control group. Combination of BGA and PZQ resulted in significant reduction in the level of intercellular adhesion molecules-1 (ICAM-1), vascular adhesion molecules-1 (VCAM-1) and tumor necrosis factor-alpha (TNF-α) when compared to those of the S. mansoni-infected group. Overall, BGA significantly inhibited the liver damage accompanied with schistosomiasis, exhibited a potent antioxidant and immunoprotective activities. This study suggests that BGA can be considered as promising for development a complementary and/or alternative medicine against schistosomiasis. Copyright © 2014 Elsevier Inc. All rights reserved.

Impaired NLRP3 Inflammasome Function in Elderly Mice during Influenza Infection is Rescued by Treatment with Nigericin1

PubMed Central

Stout-Delgado, Heather W.; Vaughan, Sarah E.; Shirali, Anushree C.; Jaramillo, Richard J.; Harrod, Kevin S.

2012-01-01

The NLRP3 inflammasome is activated in the lung during influenza viral infection; however the impact of aging on inflammasome function during influenza infection has not been examined. Here, we show that elderly mice infected with a mouse adapted strain of influenza produced lower levels of IL-1β during in vitro and in vivo infection. Dendritic cells from elderly mice exhibited decreased expression of ASC, NLRP3, and capase-1, but increased expression of pro-IL-1β, pro-IL-18, and pro-IL-33 when compared to young infected mice. Treatment with nigericin during influenza infection augmented IL-1β production, increased caspase-1 activity, and decreased morbidity and mortality in elderly mice. Our study demonstrates for the first time that during influenza viral infection, elderly mice have impaired NLRP3 inflammasome activity and that treatment with nigericin rescues NLRP3 activation in elderly hosts. PMID:22327078

Sex differences in colonization of gut microbiota from a man with short-term vegetarian and inulin-supplemented diet in germ-free mice

PubMed Central

Wang, Jing-jing; Wang, Jing; Pang, Xiao-yan; Zhao, Li-ping; Tian, Ling; Wang, Xing-peng

2016-01-01

Gnotobiotic mouse model is generally used to evaluate the efficacy of gut microbiota. Sex differences of gut microbiota are acknowledged, yet the effect of recipient’s gender on the bacterial colonization remains unclear. Here we inoculated male and female germ-free C57BL/6J mice with fecal bacteria from a man with short-term vegetarian and inulin-supplemented diet. We sequenced bacterial 16S rRNA genes V3-V4 region from donor’s feces and recipient’s colonic content. Shannon diversity index showed female recipients have higher bacteria diversity than males. Weighted UniFrac principal coordinates analysis revealed the overall structures of male recipient’s gut microbiota were significantly separated from those of females, and closer to the donor. Redundancy analysis identified 46 operational taxonomic units (OTUs) differed between the sexes. The relative abundance of 13 OTUs were higher in males, such as Parabacteroides distasonis and Blautia faecis, while 33 OTUs were overrepresented in females, including Clostridium groups and Escherichia fergusonii/Shigella sonnei. Moreover, the interactions of these differential OTUs were sexually distinct. These findings demonstrated that the intestine of male and female mice preferred to accommodate microbiota differently. Therefore, it is necessary to designate the gender of gnotobiotic mice for complete evaluation of modulatory effects of gut microbiota from human feces upon diseases. PMID:27796317

Studying NK cell responses to ectromelia virus infections in mice.

PubMed

Fang, Min; Sigal, Luis

2010-01-01

Here we describe methods for the in vivo study of antiviral NK cell responses using the mouse Orthopoxvirus ectromelia virus as a model, the agent of mousepox. The methods include those specific for the preparation and use of ectromelia virus such as the production of virus stocks in tissue culture and in live mice, the purification of virus stocks, the titration of virus stocks and virus loads in organs, and the infection of mice. The chapter also includes methods for the specific study of NK cell responses in infected mice such as the preparation of organs (lymph nodes, spleen, and liver) for analysis, the study of NK cell responses by flow cytometry, the adoptive transfer of NK cells, the measurement of NK cell cytolytic activity ex vivo and in vivo, and the determination of NK cell proliferation by bromodeoxyuridine loading or by dilution of carboxyfluorescein diacetate succinimidyl ester (CFSE).

Effect of pretreatment with chromium picolinate on haematological parameters during dengue virus infection in mice.

PubMed

Shrivastava, Richa; Nagar, R; Ravishankar, G A; Upreti, R K; Chaturvedi, U C

2007-11-01

Dengue virus (DV) has caused severe epidemics of dengue fever (DF) and dengue haemorrhagic fever (DHF) and is endemic all over India. We have earlier reported that exposure of mice to hexavalent chromium [Cr(VI)] compounds increased the severity of dengue virus infection. Trivalent chromium picolinate (CrP) is used worldwide as micronutrient and nutritional supplement. The present study was therefore, carried out to investigate the effects of CrP on various haematological parameters during DV infection of mice. The Swiss Albino smice were inoculated with dengue virus (1000 LD50, intracerebrally) and fed with chromium picolinate (CrP) in drinking water (100 and 250 mg/l) for 24 wk. Peripheral blood leucocytes and other haematological parameters, and spleens were studied on days 4 and 8 after virus inoculations and the findings were compared with those given only CrP and the normal control age matched mice. CrP in drinking water for 24 wk had no significant effects on peripheral blood cells of mice. On the other hand, there was significant decrease in different haematological parameters following inoculation of normal mice with DV. In CrP fed mice the effects of DV infection were abolished on most of the haematological parameters. The findings of present study showed that the adverse effects of DV infection, specially on platelets and leucocytes, were abrogated by pretreatment of mice with CrP. The therapeutic utility of CrP in viral infections including dengue needs to be studied in depth.

Loss of Neuronal Integrity During Progressive HIV-1 Infection of Humanized Mice

PubMed Central

Dash, Prasanta K.; Gorantla, Santhi; Gendelman, Howard E; Knibbe, Jaclyn; Casale, George P; Makarov, Edward; Epstein, Adrian A; Gelbard, Harris A; Boska, Michael D; Poluektova, Larisa Y

2011-01-01

Neuronal damage induced by ongoing HIV-1 infection was investigated in humanized NOD/scid-IL-2Rgcnull mice transplanted at birth with human CD34-positive hematopoietic stem cells. Mice infected at 5 months of age and followed for up to 15 weeks maintained significant plasma viral loads and showed reduced numbers of CD4+ T cells. Prospective serial proton magnetic resonance spectroscopy tests showed selective reductions in cortical N-acetyl aspartate in infected animals. Diffusion tensor imaging revealed structural changes in cortical gray matter. Postmortem immunofluorescence brain tissue examinations for neuronal and glial markers, captured by multispectral imaging microscopy and quantified by morphometric and fluorescence emission, showed regional reduction of neuronal soma and synaptic architectures. This was evidenced by loss of microtubule-associated protein 2, synaptophysin and neurofilament antigens. This study is the first, to our knowledge, demonstrating lost neuronal integrity following HIV-1 infection in humanized mice. As such, the model permits studies of the relationships between ongoing viral replication and virus-associated neurodegeneration. PMID:21368026

Potential antimalarial activity of Methyl Jasmonate and its effect on lipid profiles in Plasmodium Berghei infected mice.

PubMed

Oyinloye, Oladapo E; Kosoko, Ayokulehin M; Emikpe, Benjamin; Falade, Catherine O; Ademowo, Olusegun G

2015-09-01

The antimalarial activity and lipid profiles of Methyl Jasmonate (MJ) were investigated against established malaria infection in vivo using BALB/c mice. Arteether (AE) and chloroquine (CQ) were used as reference drugs while ethanol was used as the vehicle for drug delivery for MJ. Mice treated with 10 and 25 mg/kg MJ showed a remarkable reduction in percentage parasitemia by 68.3% and 78.2% on day 10(post treatment) respectively while 45.4% and 87.2% reduction in percentage parasitemia were observed in the group treated with 50 mg/kg on day 3 and 10 (post treatment) respectively. The highest mean survival time was observed in CQ followed by AE and MJ in dose-dependent manner. A progressive decrease in packed cell volume (PCV) was observed in infected untreated mice which led to the death of all the mice by day 9 (post treatment). Infected mice treated with MJ showed reduced level of HDL and LDL compared with infected untreated group. As the dose of MJ increased in infected mice cholesterol levels increased while there was reduction in triglyceride. Overall there was marked decrease in parasitemia in Plasmodium berghei infected mice treated with graded doses of MJ but appears to have reduced antimalarial activity compared with CQ and AE.

Cryptosporidium parvum infection in SCID mice infected with only one oocyst: qPCR assessment of parasite replication in tissues and development of digestive cancer.

PubMed

Benamrouz, Sadia; Guyot, Karine; Gazzola, Sophie; Mouray, Anthony; Chassat, Thierry; Delaire, Baptiste; Chabé, Magali; Gosset, Pierre; Viscogliosi, Eric; Dei-Cas, Eduardo; Creusy, Colette; Conseil, Valerie; Certad, Gabriela

2012-01-01

Dexamethasone (Dex) treated Severe Combined Immunodeficiency (SCID) mice were previously described as developing digestive adenocarcinoma after massive infection with Cryptosporidium parvum as soon as 45 days post-infection (P.I.). We aimed to determine the minimum number of oocysts capable of inducing infection and thereby gastrointestinal tumors in this model. Mice were challenged with calibrated oocyst suspensions containing intended doses of: 1, 10, 100 or 10(5) oocysts of C. parvum Iowa strain. All administered doses were infective for animals but increasing the oocyst challenge lead to an increase in mice infectivity (P = 0.01). Oocyst shedding was detected at 7 days P.I. after inoculation with more than 10 oocysts, and after 15 days in mice challenged with one oocyst. In groups challenged with lower inocula, parasite growth phase was significantly higher (P = 0.005) compared to mice inoculated with higher doses. After 45 days P.I. all groups of mice had a mean of oocyst shedding superior to 10,000 oocyst/g of feces. The most impressive observation of this study was the demonstration that C. parvum-induced digestive adenocarcinoma could be caused by infection with low doses of Cryptosporidium, even with only one oocyst: in mice inoculated with low doses, neoplastic lesions were detected as early as 45 days P.I. both in the stomach and ileo-caecal region, and these lesions could evolve in an invasive adenocarcinoma. These findings show a great amplification effect of parasites in mouse tissues after challenge with low doses as confirmed by quantitative PCR. The ability of C. parvum to infect mice with one oocyst and to develop digestive adenocarcinoma suggests that other mammalian species including humans could be also susceptible to this process, especially when they are severely immunocompromised.

B cell-deficient mice display enhanced susceptibility to Paracoccidioides brasiliensis Infection.

PubMed

Tristão, F S M; Panagio, L A; Rocha, F A; Cavassani, K A; Moreira, A P; Rossi, M A; Silva, J S

2013-08-01

Paracoccidioidomycosis (PCM) is a chronic granulomatous disease caused by the thermally dimorphic fungus Paracoccidioides brasiliensis. T helper 1 (Th1)-mediated immunity is primarily responsible for acquired resistance during P. brasiliensis infection. On the contrary, the susceptibility is associated with occurrence of type-2 immunity (Th2), which is characterized by IL-4 release, B cell activation, and production of antibodies. Although antibodies are frequently associated with severe PCM, it is not clear whether they contribute to susceptibility or merely constitute a marker of infection stage. Here, we assessed the function of B cells during experimental P. brasiliensis infection in mice, and our results showed that B cell-knockout (B(KO)) mice are more susceptible than their wild-type littermate controls (C57BL/6, WT). The B(KO) mice showed higher mortality rate, increased number of colony-forming units in the lungs, and larger granulomas than WT mice. In the absence of B cells, we observed high levels of IL-10, whereas IFN-γ, TNF-α, and IL-4 levels were similar between both groups. Finally, we showed that transference of WT immune serum to B(KO) mice resulted in diminished infiltration of inflammatory cells and better organization of the pulmonary granulomas. Taken together, these data suggest that B cells are effectively involved in the control of P. brasiliensis growth and organization of the granulomatous lesions observed during the experimental PCM.

Inhibitory effects of recombinant manganese superoxide dismutase on influenza virus infections in mice.

PubMed Central

Sidwell, R W; Huffman, J H; Bailey, K W; Wong, M H; Nimrod, A; Panet, A

1996-01-01

The oxygen free-radical scavenger recombinant human manganese superoxide dismutase (MnSOD) was studied for its effects on influenza virus infections in mice when used alone and in combination with ribavirin. Mice challenged with influenza A/NWS/33 (H1N1) virus were treated parenterally in doses of 25, 50, and 100 mg/kg of body weight per day every 8 h for 5 days beginning at 48 h post-virus exposure. An increase in mean day to death, lessened decline in arterial oxygen saturation, and reduced lung consolidation and lung virus titers occurred in the treated animals. To determine the influence of viral challenge, experiments were run in which mice were infected with a 100 or 75% lethal dose of virus and were treated intravenously once daily for 5 days beginning 96 h after virus exposure. Weak inhibition of the mortality rate was seen in mice receiving the high viral challenge, whereas significant inhibition occurred in the animals infected with the lower viral challenge, indicating that MnSOD effects are virus dose dependent. To determine if treatment with small-particle aerosol would render an antiviral effect, infected mice were treated by this route for 1 h daily for 5 days beginning 72 h after virus exposure. A dose-responsive disease inhibition was seen. An infection induced by influenza B/Hong Kong/5/72 virus in mice was mildly inhibited by intravenous MnSOD treatment as seen by increased mean day to death, lessened arterial oxygen saturation decline, and lowered lung consolidation. MnSOD was well tolerated in all experiments. A combination of MnSOD and ribavirin, each administered with small-particle aerosol, resulted in a generally mild improvement of the disease induced by the influenza A virus compared with use of either material alone. PMID:8913477

Exacerbation of allergic inflammation in mice exposed to diesel exhaust particles prior to viral infection

PubMed Central

Jaspers, Ilona; Sheridan, Patricia A; Zhang, Wenli; Brighton, Luisa E; Chason, Kelly D; Hua, Xiaoyang; Tilley, Stephen L

2009-01-01

Background Viral infections and exposure to oxidant air pollutants are two of the most important inducers of asthma exacerbation. Our previous studies have demonstrated that exposure to diesel exhaust increases the susceptibility to influenza virus infections both in epithelial cells in vitro and in mice in vivo. Therefore, we examined whether in the setting of allergic asthma, exposure to oxidant air pollutants enhances the susceptibility to respiratory virus infections, which in turn leads to increased virus-induced exacerbation of asthma. Ovalbumin-sensitized (OVA) male C57BL/6 mice were instilled with diesel exhaust particles (DEP) or saline and 24 hours later infected with influenza A/PR/8. Animals were sacrificed 24 hours post-infection and analyzed for markers of lung injury, allergic inflammation, and pro-inflammatory cytokine production. Results Exposure to DEP or infection with influenza alone had no significant effects on markers of injury or allergic inflammation. However, OVA-sensitized mice that were exposed to DEP and subsequently infected with influenza showed increased levels of eosinophils in lung lavage and tissue. In addition Th2-type cytokines, such as IL-4 and IL-13, and markers of eosinophil chemotaxis, such as CCL11 and CCR3, were increased in OVA-sensitized mice exposed to DEP prior to infection with influenza. These mice also showed increased levels of IL-1α, but not IL-10, RANTES, and MCP-1 in lung homogenates. Conclusion These data suggest that in the setting of allergic asthma, exposure to diesel exhaust could enhance virus-induced exacerbation of allergic inflammation. PMID:19682371

VIPhyb, an antagonist of vasoactive intestinal peptide receptor, enhances cellular antiviral immunity in murine cytomegalovirus infected mice.

PubMed

Li, Jian-Ming; Darlak, Kasia A; Southerland, Lauren; Hossain, Mohammad S; Jaye, David L; Josephson, Cassandra D; Rosenthal, Hilary; Waller, Edmund K

2013-01-01

Vasoactive intestinal peptide (VIP) is a neuropeptide hormone that suppresses Th1-mediated cellular immunity. We previously reported that VIP-knockout (VIP-KO) mice have enhanced cellular immune responses and increased survival following murine cytomegalovirus (mCMV) infection in C57BL/6 mice. In this study, we tested whether treatment with a VIP receptor antagonistic peptide protects C57BL/6 and BALB/c mice from mCMV-infection. One week of daily subcutaneous injections of VIPhyb was non-toxic and did not alter frequencies of immune cell subsets in non-infected mice. VIPhyb administration to mCMV-infected C57BL/6 and BALB/c mice markedly enhanced survival, viral clearance, and reduced liver and lung pathology compared with saline-treated controls. The numbers of effector/memory CD8+ T-cells and mature NK cells were increased in VIPhyb-treated mice compared with PBS-treated groups. Pharmacological blockade of VIP-receptor binding or genetic blockade of VIP-signaling prevented the up-regulation of PD-L1 and PD-1 expression on DC and activated CD8+ T-cells, respectively, in mCMV-infected mice, and enhanced CD80, CD86, and MHC-II expression on conventional and plasmacytoid DC. VIPhyb-treatment increased type-I IFN synthesis, numbers of IFN-γ- and TNF-α-expressing NK cells and T-cells, and the numbers of mCMV-M45 epitope-peptide-MHC-I tetramer CD8+ T-cells following mCMV infection. VIP-treatment lowered the percentage of Treg cells in spleens compared with PBS-treated WT mice following mCMV infection, while significantly decreasing levels of serum VEGF induced by mCMV-infection. The mice in all treated groups exhibited similar levels of anti-mCMV antibody titers. Short-term administration of a VIP-receptor antagonist represents a novel approach to enhance innate and adaptive cellular immunity in a murine model of CMV infection.

Arginine reduces Cryptosporidium parvum infection in undernourished suckling mice involving both nitric oxide synthase and arginase

PubMed Central

Castro, Ibraim C.; Oliveira, Bruna B.; Slowikowski, Jacek J.; Coutinho, Bruna P.; Siqueira, Francisco Júlio W.S.; Costa, Lourrany B.; Sevilleja, Jesus Emmanuel; Almeida, Camila A.; Lima, Aldo A.M.; Warren, Cirle A.; Oriá, Reinaldo B.; Guerrant, Richard L.

2011-01-01

Objective This study investigated the role of L-arginine supplementation to undernourished and Cryptosporidium parvum-infected suckling mice. Methods The following regimens were initiated on the 4th day of life and given subcutaneously daily: either 200mM of L-arginine or PBS for the C. parvum-infected controls. L-arginine-treated mice were grouped to receive either 20mM of NG-nitroarginine-methyl-ester (L-NAME) or PBS. Infected mice received orally 106 excysted-C. parvum oocysts on day 6 and were euthanized on day 14th at the infection peak. Results L-arginine improved weight gain compared to the untreated infected controls. L-NAME profoundly impaired body weight gain as compared to all other groups. Cryptosporidiosis was associated with ileal crypt hyperplasia, villus blunting, and inflammation. L-arginine improved mucosal histology following infection. L-NAME abrogated these arginine-induced improvements. Infected control mice showed an intense arginase expression, which was even greater with L-NAME. L-arginine reduced parasite burden, an effect that was reversed by L-NAME. C. parvum infection increased urine NO3-/NO2- concentration when compared to uninfected controls, which was increased by L-arginine supplementation, an effect that was also reversed by L-NAME. Conclusion These findings show a protective role of L-arginine during C. parvum infection in undernourished mice with involvement of arginase I and nitric oxide synthase enzymatic actions. PMID:22261576

Widespread bronchogenic dissemination makes DBA/2 mice more susceptible than C57BL/6 mice to experimental aerosol infection with Mycobacterium tuberculosis.

PubMed

Cardona, Pere-Joan; Gordillo, Sergi; Díaz, Jorge; Tapia, Gustavo; Amat, Isabel; Pallarés, Angeles; Vilaplana, Cristina; Ariza, Aurelio; Ausina, Vicenç

2003-10-01

We have used the murine model of aerosol-induced experimental tuberculosis to assess the effects of four clinical isolates and a reference strain of Mycobacterium tuberculosis on resistant C57BL/6 mice and susceptible DBA/2 mice. Histological studies and detection of 25 cytokines potentially involved in the infection were carried out. DBA/2 mice showed higher concentrations of bacilli in bronchoalveolar lavage fluid and lung tissue. Furthermore, these mice evidenced a larger granulomatous infiltration in the parenchyma due to an increased rate of emigration of infected foamy macrophages from the granulomas to the neighboring pulmonary alveolar spaces. The better control of bacillary concentrations and pulmonary infiltration observed in C57BL/6 mice from week 3 postinfection could result from their higher RANTES, ICAM-1, and gamma interferon (IFN-gamma) mRNA levels. On the other hand, the higher MIP-2 and MCP-3 mRNA levels seen in DBA/2 mice would result in stronger lung recruitment of macrophages and neutrophils. Additionally, DBA/2 mice showed increased inducible nitric oxide synthase expression, induced by the larger number of foamy macrophages, at weeks 18 and 22. This increment was a consequence of phagocytosed bacillary debris, was independent of IFN-gamma expression, and could exert only a bacteriostatic effect. The results of the study suggest that DBA/2 mice are more susceptible than C57BL/6 mice to M. tuberculosis infection due to a higher bronchial dissemination of bacilli inside poorly activated foamy macrophages.

Lack of infectivity of HBV in feces from patients with chronic hepatitis B virus infection, and infection using chimeric mice.

PubMed

Komatsu, Haruki; Inui, Ayano; Murano, Takeyoshi; Tsunoda, Tomoyuki; Sogo, Tsuyoshi; Fujisawa, Tomoo

2015-08-20

Body fluids such as saliva and tears from patients with hepatitis B virus (HBV) infection are known as infectious agents. The infectivity of feces from patients with HBV infection has not been established. The aim of this study was to determine whether feces from HBV carriers can be a source of HBV infection. Thirty-three children and 17 adults (ages 0-49 years, median age 13 years) who were chronically infected with HBV were enrolled. The levels of HBV DNA in the feces from these patients were quantified by real-time PCR, and the levels of fecal HBsAg were measured. Isolated human hepatocytes from chimeric mice with humanized livers were co-cultured with serum, tears and feces from the HBV carriers. Four chimeric mice were inoculated intravenously with sterilized feces from HBV carriers. HBV DNA was detected in the feces of 37 (74%) of the 50 patients. The fecal HBV DNA levels ranged from 2.8 to 8.4 log copies/mL (mean ± SD  =  5.6 ± 1.2 log copies/mL). A significant correlation was observed in the levels of HBV DNA between serum and feces (r  =  0.54, p < 0.05). Of the 13 HBV carries, 7 (54%) were positive for fecal HBsAg. The fecal HBsAg levels ranged from 0.06 to 1.0 IU/mL (median 0.28 IU/mL). Immunogold electron microscopy showed Dane particles in feces. HBV DNA was detected in the human hepatocytes co-cultured with serum and tears, but not in those co-cultured with feces. HBV DNA was not detected in the serum of the chimeric mice after oral or intravenous inoculation with sterilized fecal samples, which contained 5 log copies/mL of HBV DNA levels. Although the positive rate of fecal HBV DNA was high, the fecal HBsAg levels were extremely low. The chimeric mice were not infected with HBV after oral or intravenous inoculation with sterilized fecal samples. Therefore, feces from HBV carriers seem not to serve as an infectious vehicle for the transmission of HBV.

The flame-retardant BDE-99 dose-dependently affects viral replication in CVB3-infected mice.

PubMed

Lundgren, Magnus; Darnerud, Per Ola; Ilbäck, Nils-Gunnar

2013-06-01

The flame retardant component 2,2',4,4',5-penta-BDE (BDE-99) is found in the environment and in human tissues and fluids. In mice the common human coxsackievirus B3 (CVB3) infection has been shown to change the tissue distribution of BDE-99. We now investigate how CVB3 infection in mice affects liver uptake of (14)C at two doses of radiolabelled BDE-99, and whether increased tissue levels are related to changed virus replication and gene expression of the proinflammatory chemokine monocyte chemoattractant protein-1 (MCP-1). Mice were infected on day 0, orally treated either with 200μg or 20mg (14)C-BDE-99/kgbw on day 1, and euthanised on day 3. Serum and liver levels of (14)C-BDE-99, as well as virus levels and gene expressions of MCP-1 in the liver, were measured. In non-infected mice, there was a dose-dependent uptake of BDE-99 in both liver and serum, and in infected animals the liver BDE-99 levels was further increased. When comparing infected mice exposed to the two BDE-99 doses, the higher BDE dose resulted in increased virus amounts in the liver, and decreased infection-induced expression of MCP-1. Consequently, a high enough dose/tissue concentration of BDE-99 may result in a disturbed mobilisation of immune cells into infected tissues that could explain higher virus titres and a possibly altered clinical course of the disease. Moreover, the fact that CVB3 infection increased the BDE-99 levels in liver but not in serum may impair the risk assessment of polybrominated diphenyl ethers (PBDEs) in subclinical and clinically infected individuals, as serum levels is the common marker of exposure. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of infection by Toxoplasma gondii on purine levels and E-ADA activity in the brain of mice experimentally infected mice.

PubMed

Tonin, Alexandre A; Da Silva, Aleksandro S; Casali, Emerson A; Silveira, Stephanie S; Moritz, Cesar E J; Camillo, Giovana; Flores, Mariana M; Fighera, Rafael; Thomé, Gustavo R; Morsch, Vera M; Schetinger, Maria Rosa C; Rue, Mario De La; Vogel, Fernanda S F; Lopes, Sonia T A

2014-07-01

The aim of this study was to assess the purine levels and E-ADA activity in the brain of mice (BALB/c) experimentally infected with Toxoplasma gondii. In experiment I (n=24) the mice were infected with RH strain of T. gondii, while in experiment II (n=36) they were infected with strain ME-49 of T. gondii. Our results showed that, for RH strain (acute phase), an increase in both periods in the levels of ATP, ADP, AMP, adenosine, hypoxanthine, xanthine (only on day 6 PI) and uric acid (only on day 6 PI). By the other hand, the RH strain led, on days 4 and 6 PI, to a reduction in the concentration of inosine. ME-49, a cystogenic strain, showed some differences in acute and chronic phase, since on day 6 PI the levels of ATP and ADP were increased, while on day 30 these same nucleotides were reduced. On day 60 PI, ME-49 induced a reduction in the levels of ATP, ADP, AMP, adenosine, inosine and xanthine, while uric acid was increased. A decrease of E-ADA activity was observed in brain on days 4 and 6 PI (RH), and 30 PI (ME-49); however on day 60 PI E-ADA activity was increased for infection by ME-49 strain. Therefore, it was possible to conclude that infection with T. gondii changes the purine levels and the activity of E-ADA in brain, which may be associated with neurological signs commonly observed in this disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Intradermal infections of mice by low numbers of african trypanosomes are controlled by innate resistance but enhance susceptibility to reinfection.

PubMed

Wei, Guojian; Bull, Harold; Zhou, Xia; Tabel, Henry

2011-02-01

Antibodies are required to control blood-stage forms of African trypanosomes in humans and animals. Here, we report that intradermal infections by low numbers of African trypanosomes are controlled by innate resistance but prime the adaptive immune response to increase susceptibility to a subsequent challenge. Mice were found 100 times more resistant to intradermal infections by Trypanosoma congolense or Trypanosoma brucei than to intraperitoneal infections. B cell-deficient and RAG2(-/-) mice are as resistant as wild-type mice to intradermal infections, whereas inducible nitric oxide synthase (iNOS)(-/-) mice and wild-type mice treated with antibody to tumor necrosis factor (TNF) α are more susceptible. We conclude that primary intradermal infections with low numbers of parasites are controlled by innate defense mediated by induced nitric oxide (NO). CD1d(-/-) and major histocompatibility complex (MHC) class II(-/-) mice are more resistant than wild-type mice to primary intradermal infections. Trypanosome-specific spleen cells, as shown by cytokine production, are primed as early as 24 h after intradermal infection. Infecting mice intradermally with low numbers of parasites, or injecting them intradermally with a trypanosomal lysate, makes mice more susceptible to an intradermal challenge. We suggest that intradermal infections with low numbers of trypanosomes or injections with trypanosomal lysates prime the adaptive immune system to suppress protective immunity to an intradermal challenge.

Serial Histopathological Examination of the Lungs of Mice Infected with Influenza A Virus PR8 Strain

PubMed Central

Fukushi, Masaya; Ito, Tateki; Oka, Teruaki; Kitazawa, Toshio; Miyoshi-Akiyama, Tohru; Kirikae, Teruo; Yamashita, Makoto; Kudo, Koichiro

2011-01-01

Avian influenza H5N1 and pandemic (H1N1) 2009 viruses are known to induce viral pneumonia and subsequent acute respiratory distress syndrome (ARDS) with diffuse alveolar damage (DAD). The mortality rate of ARDS/DAD is extremely high, at approximately 60%, and no effective treatment for ARDS/DAD has been established. We examined serial pathological changes in the lungs of mice infected with influenza virus to determine the progress from viral pneumonia to ARDS/DAD. Mice were intranasally infected with influenza A/Puerto Rico/8/34 (PR8) virus, and their lungs were examined both macro- and micro-pathologically every 2 days. We also evaluated general condition, survival rate, body weight, viral loads in lung, and surfactant proteins in serum. As a result, all infected mice died within 9 days postinfection. At 2 days postinfection, inflammation in alveolar septa, i.e., interstitial pneumonia, was observed around bronchioles. From 4 to 6 days postinfection, interstitial pneumonia with alveolar collapse expanded throughout the lungs. From 6 to 9 days postinfection, DAD with severe alveolar collapse was observed in the lungs of all of dying and dead mice. In contrast, DAD was not observed in the live infected-mice from 2 to 6 days postinfection, despite their poor general condition. In addition, histopathological analysis was performed in mice infected with a dose of PR8 virus which was 50% of the lethal dose for mice in the 20-day observation period. DAD with alveolar collapse was observed in all dead mice. However, in the surviving mice, instead of DAD, glandular metaplasia was broadly observed in their lungs. The present study indicates that DAD with severe alveolar collapse is associated with death in this mouse infection model of influenza virus. Inhibition of the development of DAD with alveolar collapse may decrease the mortality rate in severe viral pneumonia caused by influenza virus infection. PMID:21701593

The effect of herbal remedy on the development of Trichinella spiralis infection in mice.

PubMed

Bany, J; Zdanowska, D; Zdanowski, R; Skopińska-Rózewska, E

2003-01-01

The effect of Alchinal (a complex preparation consisting of three substances: Echinacea purpurea extract, Allium sativum extract, cocoa) on the development of Trichinella spiralis infection in mice was studied. The preparation was administered to the animals orally, twice a day in 30 microl doses for 10 days after infecting mice with Trichinella larvae (500 larvae per mouse). It was demonstrated that after Alchinal administration, the number of adult forms (10 dpi--days post infection) and muscular larvae (36 dpi) significantly decreased. It is suggested that the remedy studied causes antiparasitic immunity enhancement in mice. Modulation of immunity by individual component(s) and/or joint action of the substances contained in Alchinal increases the antiparasitic defence of the organism.

Influence of environmental enrichment on the behavior and physiology of mice infected by Trypanosoma cruzi.

PubMed

Silva, Déborah Maria Moreira da; Pinheiro, Laila; Azevedo, Cristiano Schetini; Costa, Guilherme de Paula; Talvani, André

2017-01-01

Enriched environments normally increase behavioral repertoires and diminish the expression of abnormal behaviors and stress-related physiological problems in animals. Although it has been shown that experimental animals infected with microorganisms can modify their behaviors and physiology, few studies have evaluated how environmental enrichment affects these parameters. This study aimed to evaluate the effects of environmental enrichment on the behavior and physiology of confined mice infected with Trypanosoma cruzi. The behaviors of 20 T. cruzi-infected mice and 20 non-infected mice were recorded during three treatments: baseline, enrichment, and post-enrichment. Behavioral data were collected using scan sampling with instantaneous recording of behavior every 30s, totaling 360h. Plasma TNF, CCL2, and IL-10 levels and parasitemia were also evaluated in infected enriched/non-enriched mice. Behavioral data were evaluated by Friedman's test and physiological data by one-way ANOVA and area under the curve (AUC) analysis. Results showed that environmental enrichment significantly increased exploratory behaviors and diminished inactivity. The use of environmental enrichment did not diminish circulating levels of TNF and IL-10 but diminished circulating levels of CCL2 and parasitemia. Positive behavioral and physiological effects of environmental enrichment were observed in mice living in enriched cages. Thus, environmental enrichment improved the welfare of these animals.

Development of an in vivo model of Chlamydia abortus chronic infection in mice overexpressing IL-10.

PubMed

Del Río, Laura; Murcia, Antonio; Buendía, Antonio J; Álvarez, Daniel; Ortega, Nieves; Navarro, José A; Salinas, Jesús; Caro, María Rosa

2018-01-01

Chlamydia abortus, like other members of the family Chlamydiaceae, have a unique intracellular developmental cycle that is characterized by its chronic nature. Infection of a flock can remain undetected for months, until abortion occurs the following reproductive season but, to date, neither the location nor the mechanisms that maintain this latent phase are fully understood. Studies have shown that IL-10 produced as a response to certain micro-organisms sustains the intracellular survival of pathogens and increases host susceptibility to chlamydial infections. In order to induce a sustained infection C. abortus, transgenic mice that constitutively express IL-10 were infected and the immunological mechanisms that maintain infection in these mice were compared with the mechanisms of a resistant wild-type mouse strain. Viable bacteria could be detected in different tissues of transgenic mice up to 28 days after infection, as analysed by bacterial isolation and immunohistochemistry. Chronic infection in these mice was associated with an impaired recruitment of macrophages, decreased iNOS activity at the site of infection and a more diffuse distribution of inflammatory cells in the liver. This murine model can be of great help for understanding the immunological and bacterial mechanisms that lead to chronic chlamydial infections. Copyright © 2017 Elsevier B.V. All rights reserved.

Systemic and Mucosal Immune Reactivity upon Mycobacterium avium ssp. paratuberculosis Infection in Mice

PubMed Central

Suwandi, Abdulhadi; Roderfeld, Martin; Tschuschner, Annette; Rath, Timo; Gerlach, Gerald F.; Hornef, Mathias; Goethe, Ralph; Weiss, Siegfried; Roeb, Elke

2014-01-01

Mycobacterium avium ssp. paratuberculosis (MAP) is the cause of Johne's disease, an inflammatory bowel disorder of ruminants. Due to the similar pathology, MAP was also suggested to cause Crohn's disease (CD). Despite of intensive research, this question is still not settled, possibly due to the lack of versatile mouse models. The aim of this study was to identify basic immunologic mechanisms in response to MAP infection. Immune compromised C57BL/6 Rag2 −/− mice were infected with MAP intraperitoneally. Such chronically infected mice were then reconstituted with CD4+ and CD8+ T cells 28 days after infection. A systemic inflammatory response, detected as enlargement of the spleen and granuloma formation in the liver, was observed in mice infected and reconstituted with CD4+ T cells. Whereby inflammation in infected and CD4+CD45RBhi T cell reconstituted animals was always higher than in the other groups. Reconstitution of infected animals with CD8+ T cells did not result in any inflammatory signs. Interestingly, various markers of inflammation were strongly up-regulated in the colon of infected mice reconstituted with CD4+CD45RBlo/int T cells. We propose, the usual non-colitogenic CD4+CD45RBlo/int T cells were converted into inflammatory T cells by the interaction with MAP. However, the power of such cells might be not sufficient for a fully established inflammatory response in the colon. Nevertheless, our model system appears to mirror aspects of an inflammatory bowel disease (IBD) like CD and Johne's diseases. Thus, it will provide an experimental platform on which further knowledge on IBD and the involvement of MAP in the induction of CD could be acquired. PMID:24728142

Systemic and mucosal immune reactivity upon Mycobacterium avium ssp. paratuberculosis infection in mice.

PubMed

Koc, Arzu; Bargen, Imke; Suwandi, Abdulhadi; Roderfeld, Martin; Tschuschner, Annette; Rath, Timo; Gerlach, Gerald F; Hornef, Mathias; Goethe, Ralph; Weiss, Siegfried; Roeb, Elke

2014-01-01

Mycobacterium avium ssp. paratuberculosis (MAP) is the cause of Johne's disease, an inflammatory bowel disorder of ruminants. Due to the similar pathology, MAP was also suggested to cause Crohn's disease (CD). Despite of intensive research, this question is still not settled, possibly due to the lack of versatile mouse models. The aim of this study was to identify basic immunologic mechanisms in response to MAP infection. Immune compromised C57BL/6 Rag2-/- mice were infected with MAP intraperitoneally. Such chronically infected mice were then reconstituted with CD4+ and CD8+ T cells 28 days after infection. A systemic inflammatory response, detected as enlargement of the spleen and granuloma formation in the liver, was observed in mice infected and reconstituted with CD4+ T cells. Whereby inflammation in infected and CD4+CD45RB(hi) T cell reconstituted animals was always higher than in the other groups. Reconstitution of infected animals with CD8+ T cells did not result in any inflammatory signs. Interestingly, various markers of inflammation were strongly up-regulated in the colon of infected mice reconstituted with CD4+CD45RB(lo/int) T cells. We propose, the usual non-colitogenic CD4+CD45RB(lo/int) T cells were converted into inflammatory T cells by the interaction with MAP. However, the power of such cells might be not sufficient for a fully established inflammatory response in the colon. Nevertheless, our model system appears to mirror aspects of an inflammatory bowel disease (IBD) like CD and Johne's diseases. Thus, it will provide an experimental platform on which further knowledge on IBD and the involvement of MAP in the induction of CD could be acquired.

Mice chronically infected with chimeric HIV resist peripheral and brain superinfection: a model of protective immunity to HIV.

PubMed

Kelschenbach, Jennifer L; Saini, Manisha; Hadas, Eran; Gu, Chao-Jiang; Chao, Wei; Bentsman, Galina; Hong, Jessie P; Hanke, Tomas; Sharer, Leroy R; Potash, Mary Jane; Volsky, David J

2012-06-01

Infection by some viruses induces immunity to reinfection, providing a means to identify protective epitopes. To investigate resistance to reinfection in an animal model of HIV disease and its control, we employed infection of mice with chimeric HIV, EcoHIV. When immunocompetent mice were infected by intraperitoneal (IP) injection of EcoHIV, they resisted subsequent secondary infection by IP injection, consistent with a systemic antiviral immune response. To investigate the potential role of these responses in restricting neurotropic HIV infection, we established a protocol for efficient EcoHIV expression in the brain following intracranial (IC) inoculation of virus. When mice were inoculated by IP injection and secondarily by IC injection, they also controlled EcoHIV replication in the brain. To investigate their role in EcoHIV antiviral responses, CD8+ T lymphocytes were isolated from spleens of EcoHIV infected and uninfected mice and adoptively transferred to isogenic recipients. Recipients of EcoHIV primed CD8+ cells resisted subsequent EcoHIV infection compared to recipients of cells from uninfected donors. CD8+ spleen cells from EcoHIV-infected mice also mounted modest but significant interferon-γ responses to two HIV Gag peptide pools. These findings suggest EcoHIV-infected mice may serve as a useful system to investigate the induction of anti-HIV protective immunity for eventual translation to human beings.

Suppression of humoral response during the course of Candida albicans infection in mice.

PubMed

Valdez, J C; Meson, O E; de Valdez, G A; Sirena, A

1984-10-30

This paper aims at demonstrating the non-specific immunosuppression as regards thyme-dependent antigens sheep erythrocytes (SRBC) during the course of Candida albicans systemic infection. Three lots of syngeneic/BALB/c mice, 8-12 weeks of age, were used. The first normal lot was inoculated via the intraperitoneal route with a (SRBC) suspension (4 X 10(8) cells ml) in a Hank's balanced saline solution. The primary response of antibodies formed by splenic cells was measured from 4 to 8 days after inoculation using the direct plaque forming cells technique. The second lot was infected by the same route with a suspension of Candida albicans (1 X 10(7) cells). Positive retrocultures from the blood and kidneys of these infected mice were obtained. These yeasts cultivated in a Sabouraud medium were harvested after 20 h at 37 degrees C. Following the same methodology the immune response to SRBC was determined. The serum obtained from infected mice was transferred to a third lot of mice at different intervals during the course of the infection. The immune response to SRBC was done by the direct plaque-forming cells technique. Controls were carried out using normal donors and recipients. A suppression of the immune response was obtained as from the 2nd day of inoculation up to the 28th day. It was not possible to transfer such suppression passively by means of the serum. These results suggest that the systemic infection by Candida albicans induce a non-specific immunosuppression in the organism, already demonstrated in viral infections, bacteria, protozoaria and metazoaria in mammals. In some way, this will contribute to explain the mechanisms of immune response to Candida albicans.

Influence of Echinococcus multilocularis infection on reproduction and cellular immune response of mice.

PubMed

Antolová, D; Reiterová, K

2010-05-01

The influence of secondary Echinococcus multilocularis infection on reproduction and cellular immune response of mice was studied in BALB/c mice infected with 2000 E. multilocularis protoscoleces. Of the total infected mothers, 11.7% did not give birth and 10% of uninfected ones did not deliver. Both, healthy and infected mothers, produced on average 6-7 offspring per litter. The changes in production of seral IFN-gamma, TNF and IL-10 did not significantly influence the course of gravidity. On the other hand, more intensive metacestode growth was observed after the delivery. This study confirmed the ability of host organism to adapt to severe damage caused by E. multilocularis, not only in normal conditions, but also during pregnancy.

Abnormal immune response of CCR5-deficient mice to ocular infection with herpes simplex virus type 1

PubMed Central

Carr, Daniel J.J.; Ash, John; Lane, Thomas E.; Kuziel, William A.

2006-01-01

Summary Ocular herpes simplex virus type 1 (HSV-1) infection elicits a strong inflammatory response that is associated with production of the β chemokines CCL3 and CCL5, which share a common receptor, CCR5. To gain insight into the role of these molecules in ocular immune responses, we infected the corneas of WT and CCR5-deficient (CCR5-/-) mice with HSV-1 and measured inflammatory parameters. In the absence of CCR5, the early infiltration of neutrophils into the cornea was diminished. Associated with this aberrant leukocyte recruitment, neutrophils in CCR5-/- mice were restricted to the stroma whereas in wild type mice these cells trafficked to the stroma and epithelial layers of the infected cornea. Virus titers and cytokine/chemokine levels in the infected tissue of these mice were similar for the first 5 days after infection. However, by day 7 post-infection, the CCR5-/- mice showed a significant elevation in the chemokines CCL2, CCL5, CXCL9, and CXCL10 in the trigeminal ganglion and brain stem as well as a significant increase in viral burden. The increase in chemokine expression was associated with an increase in the infiltration of CD4 and/or CD8 T cells into the trigeminal ganglion and brain stem of CCR5-/- mice. Surprisingly, even though infected CCR5-/- mice were less efficient at controlling the progression of virus replication, there was no difference in mortality. These results suggest that, although CCR5 plays a role in regulating leukocyte trafficking and control of virus burden, compensatory mechanisms are involved in preventing mortality following HSV-1 infection. PMID:16476970

Virus-like particle-based vaccine against coxsackievirus A6 protects mice against lethal infections.

PubMed

Shen, Chaoyun; Ku, Zhiqiang; Zhou, Yu; Li, Dapeng; Wang, Lili; Lan, Ke; Liu, Qingwei; Huang, Zhong

2016-07-25

Coxsackievirus A6 (CA6) is emerging as one of the major causative agents of hand, foot, and mouth disease (HFMD) worldwide. However, no vaccine is currently available for preventing CA6 infection. Here, we report the development of a virus-like particle (VLP)-based recombinant vaccine for CA6. We produced CA6 VLPs in insect cells by infecting the cells with a baculovirus coexpressing the genes encoding CA6 P1 and 3CD. Biochemical analyses showed that the produced VLPs consisted of VP0, VP1, and VP3 capsid subunit proteins generated by the cleavage of P1 by 3CD. Mice immunized with these VLPs produced CA6-specific serum antibodies. Passive transfer of antisera from CA6 VLP-immunized mice protected recipient mice from lethal infections caused by homologous and heterologous CA6 strains. Moreover, active immunization of mice with CA6 VLPs efficiently conferred protection against both homologous and heterologous CA6 infections. These results suggested that CA6 VLP-based recombinant vaccine is a promising candidate vaccine for preventing CA6 infection and can be incorporated into a multivalent HFMD vaccine formulation to achieve broad-spectrum and effective prevention of this disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

BALB/c mice resistant to Toxoplasma gondii infection proved to be highly susceptible when previously infected with Myocoptes musculinus fur mites

PubMed Central

Welter, Áurea; Mineo, José Roberto; de Oliveira Silva, Deise Aparecida; Lourenço, Elaine Vicente; Ferro, Eloísa Amália Vieira; Roque-Barreira, Maria Cristina; da Silva, Neide Maria

2007-01-01

Summary The immune response induced by Toxoplasma gondii is characterized by Th1 immune mechanisms. We previously demonstrated that C57BL/6 mice infested with Myocoptes musculinus and infected with T. gondii by intraperitoneal route undergo accelerated mortality according to Th2 immune mechanisms induced by the acarian. To evaluate whether infection with M. musculinus influences T. gondii-induced Th1 response in a resistant mouse lineage, BALB/c, which develops latent chronic toxoplasmosis in a way similar to that observed in immunocompetent humans, this study was done. The animals were infected with T. gondii ME-49 strain 1 month after M. musculinus infestation, being the survival and the immune response monitored. The double-infected displayed higher mortality rate if compared with the mono-infected mice. In addition, infection with M. musculinus changed the T. gondii-specific immune response, converting BALB/c host to a susceptible phenotype. Spleen cells had increased the levels of IL-4 in double-infected mice. This alteration was associated with severe pneumonia, encephalitis and wasting condition. In addition, a higher tissue parasitism was observed in double-infected animals. It can be concluded that infection with these two contrasting parasites, M. musculinus and T. gondii, may convert an immunocompetent host into a susceptible one, and such a host will develop severe toxoplasmosis. PMID:17877534

Profile of cytokines in the lungs of BALB/c mice after intra-nasal infection with Histoplasma capsulatum mycelial propagules.

PubMed

Sahaza, Jorge Humberto; Suárez-Alvarez, Roberto; Estrada-Bárcenas, Daniel Alfonso; Pérez-Torres, Armando; Taylor, Maria Lucia

2015-08-01

The host pulmonary response to the fungus Histoplasma capsulatum was evaluated, through the profile of cytokines detected by the MagPix magnetic beads platform in lung homogenates and by lung-granulomas formation, from mice intra-nasally infected with mycelial propagules (M-phase) of two virulent H. capsulatum strains, EH-46 and G-217B. Results highlight that mice lung inflammatory response depends on the H. capsulatum strain used, during the first step of the fungal infection. IL-1β and TNF-α increased their concentrations in mice infected with both strains. The highest levels of IL-6, IL-17, and IL-23 were found in EH-46-infected mice, whereas levels of IL-22 were variable at all post-infection times for both strains. Significant increases of IL-12, IFN-γ, IL-4, and IL-10 were associated to EH-46-infected mice. Histological lung findings from EH-46-infected mice revealed incipient and numerous well-developed granulomas, distributed in lung-lobes at the 14th and the 21st days after infection, according to cytokine profiles. Copyright © 2015 Elsevier Ltd. All rights reserved.

Role of major histocompatibility complex class II in resistance of mice to naturally acquired infection with Syphacia obvelata

NASA Technical Reports Server (NTRS)

Stewart, Patricia W.; Chapes, Stephen K.

2003-01-01

Genetics plays a substantial role in host resistance in many host-parasite interactions. We examined the prevalence of naturally acquired infection with Syphacia obvelata in a number of mouse strains housed in a non-barrier facility. These mice, which included cross-bred and congenic, inbred strains on various genetic backgrounds, differ in the loci for the immune function genes--major histocompatibility complex class II (MHCII), toll-like receptor 4 (Tlr4), and solute carrier family 11, member 1 (Slc11a1)--which allowed comparisons of the impact of these genes on resistance to pinworm infection. Male and female mice of various ages were sampled over an 18-month period; infection was determined by use of the cellophane tape test. Results indicated that mice that were MHCII+/+ had a significantly lower prevalence of infection than did mice that were MHCII-/-. Differences were not seen between male and female mice. Although MHCII+/+ mice had an age-associated decrease in infection prevalence, such decrease was not seen in MHCII-/- mice. In contrast, infection prevalence in mice with the normal Tlr4 gene (Tlr4(LPS-n/LPS-n)) gene did not differ significantly compared with that in mice that were homozygous for either the point mutation (Tlr4(LPS-d/LPS-d)) or deletion (Tlr4(LPS-del/LPS-del)) of that gene. Likewise, the presence (Sle11a1r/r) or absence (Slc11a1s/s) of functional alleles for Slc11a1 had no effect on the prevalence of infection with S. obvelata. In conclusion, presence of MHCII, but not Tlr4 or Slc11a1 significantly influences prevalence of naturally acquired infection with S. obvelata. These data justify further comprehensive analyses of the immune components that are involved in pinworm resistance.

Effect of treatment with interferon-gamma and concanavalin A on the course of infection of mice with Salmonella typhimurium strain LT-2

NASA Technical Reports Server (NTRS)

Gould, Cheryl L.; Sonnenfeld, Gerald

1987-01-01

The effect of pretreatment of mice with 34 units/day, for five days, of interferon-gamma (IFN-gamma) on the course of infection with LD50 of Salmonella typhimurium strain LT-2 was assessed, using two IFN preparations: (1) a hybridoma supernatant fluid containing concanavalin-A-induced IFN-gamma activity and (2) pure murine IFN-gamma produced by recombinant DNA technology. The hybridoma supernatant-treated Salmonella-infected mice were found to die faster than mice treated only with Salmonella. Pure murine IFN-gamma was found to protect infected mice significantly, with 95 percent of mice surviving LD50 infection. In contrast, the Salmonella-infected mice treated with hybridoma supernatant were found to die faster than the Salmonella-infected untreated controls. Mice treated with concanavalin A alone prior to infection with S. typhimurium died more quickly than the untreated infected controls, suggesting that contamination with concanavalin A had a detrimental effect on mice survival.

Hemorrhage-induced intestinal damage is complement independent in Helicobacter-hepaticus infected mice

PubMed Central

Hylton, Diana J.; Phillips, Lauren M.; Hoffman, Sara M.; Fleming, Sherry D.

2010-01-01

With over half of the world population infected, Helicobacter infection is an important public health issue associated with gastrointestinal cancers and inflammatory bowel disease. Animal studies indicate that complement and oxidative stress play a role in Helicobacter infections. Hemorrhage induces tissue damage which is attenuated by blockade of either complement activation or oxidative stress products. Therefore, we hypothesized that chronic Helicobacter hepaticus infection would modulate hemorrhage-induced intestinal damage and inflammation. To test this hypothesis, we examined hemorrhage-induced jejunal damage and inflammation in uninfected and H. hepaticus infected mice. H. hepaticus infection increased hemorrhage-induced mid-jejunal mucosal damage despite attenuating complement activation. In addition, infection alone increased chemokine secretion, changing the hemorrhage-induced neutrophil infiltration to a macrophage-mediated inflammatory response. The hemorrhage-induced macrophage infiltration correlated with increased secretion of tumor necrosis factor-α (TNF-α3) and nitric oxide (NO) in the infected mice. Together these data indicate that Helicobacter infection modulates the mechanism of hemorrhage-induced intestinal damage and inflammation from a complement-mediated response to a macrophage response with elevated TNF-α and NO. These data indicate that chronic, low level infections change the response to trauma and should be considered when designing and administering therapeutics. PMID:20220569

Eosinophilia, parasite burden and lung damage in Toxocara canis infection in C57Bl/6 mice genetically deficient in IL-5.

PubMed Central

Takamoto, M; Ovington, K S; Behm, C A; Sugane, K; Young, I G; Matthaei, K I

1997-01-01

C57Bl/6 mice genetically deficient in interleukin (IL)-5 (IL-5-/-) and mice with the normal IL-5 gene (IL-5+/+) were infected with embryonated eggs of Toxocara canis. IL-5+/+ mice developed a marked eosinophilia in their peripheral bloods and bone marrows after infection. In contrast, the number of eosinophils at these sites actually decreased during the acute phase of infection in IL-5-/- mice. A smaller number of eosinophils infiltrated the lung, liver, heart and skeletal muscle of infected IL-5-/- mice than those of infected IL-5+/+ mice. Eosinophils were not produced in cultures of bone marrow cells from either IL-5+/+ or IL-5-/- mice which were stimulated with excretory secretory antigen of T. canis larvae. The capacity of cells from the bone marrow to differentiate into eosinophils when stimulated in vitro with recombinant murine IL-5 was the same whether the cells were from IL-5+/+ or IL-5-/- mice. Taken together, these results show that an IL-5-like molecule is not produced by the T. canis larvae and that IL-5 produced by host cells is solely responsible for the eosinophilia in mice infected with this nematode. The number and location of T. canis larvae were not altered in the absence of IL-5. In contrast, lung damage in infected IL-5-/- mice was less extensive than that in infected IL-5+/+ mice, although structures resembling Charcot-Leyden crystals were seen in the lungs of both IL-5+/+ and IL-5-/- mice. These results suggest that eosinophils play a role in the pathology in mice infected with T. canis. Images Figure 3 PMID:9176103

Depletion of Neutrophils Exacerbates the Early Inflammatory Immune Response in Lungs of Mice Infected with Paracoccidioides brasiliensis

PubMed Central

Lopera, Damaris; Urán-Jiménez, Martha Eugenia

2016-01-01

Neutrophils predominate during the acute phase of the Paracoccidioides brasiliensis infection. Herein, we determined the role of the neutrophil during the early stages of experimental pulmonary paracoccidioidomycosis using a monoclonal antibody (mAb) specific for neutrophils. Male BALB/c mice were inoculated intranasally with 1.5 × 106 or 2 × 106 P. brasiliensis yeast cells. The mAb was administered 24 h before infection, followed by doses every 48 h until mice were sacrificed. Survival time was evaluated and mice were sacrificed at 48 h and 96 h after inoculation to assess cellularity, fungal load, cytokine/chemokine levels, and histopathological analysis. Neutrophils from mAb-treated mice were efficiently depleted (99.04%). Eighty percent of the mice treated with the mAb and infected with 1.5 × 106 yeast cells died during the first two weeks after infection. When mice were treated and infected with 2 × 106 yeast cells, 100% of them succumbed by the first week after infection. During the acute inflammatory response significant increases in numbers of eosinophils, fungal load and levels of proinflammatory cytokines/chemokines were observed in the mAb-treated mice. We also confirmed that neutrophils are an important source of IFN-γ and IL-17. These results indicate that neutrophils are essential for protection as well as being important for regulating the early inflammatory immune response in experimental pulmonary paracoccidioidomycosis. PMID:27642235

Canine H3N8 influenza virus infection in dogs and mice.

PubMed

Castleman, W L; Powe, J R; Crawford, P C; Gibbs, E P J; Dubovi, E J; Donis, R O; Hanshaw, D

2010-05-01

An H3N8 influenza virus closely related to equine influenza virus was identified in racing greyhound dogs with respiratory disease in 2004 and subsequently identified in shelter and pet dogs. Pathologic findings in dogs spontaneously infected with canine influenza virus were compared with lesions induced in beagle and mongrel dogs following experimental inoculation with influenza A/canine/Florida/43/2004. BALB/c mice were inoculated with canine influenza virus to assess their suitability as an experimental model for viral pathogenesis studies. All dogs inoculated with virus developed necrotizing and hyperplastic tracheitis and bronchitis with involvement of submucosal glands as well as mild bronchiolitis and pneumonia. Viral antigen was identified in bronchial and tracheal epithelial cells of all dogs and in alveolar macrophages of several dogs. Many dogs that were spontaneously infected with virus also developed bacterial pneumonia, and greyhound dogs with fatal spontaneous infection developed severe pulmonary hemorrhage with hemothorax. Virus-inoculated BALB/c mice developed tracheitis, bronchitis, bronchiolitis, and mild pneumonia in association with viral antigen in airway epithelial cells and in type 2 alveolar epithelial cells. Virus was not detected in extrarespiratory sites in any animals. The results indicate that canine influenza virus infection consistently induces acute tracheitis and bronchitis in dogs. Mice may be a useful model for some pathogenesis studies on canine influenza virus infection.

Transcriptional analysis of immune-related gene expression in p53-deficient mice with increased susceptibility to influenza A virus infection.

PubMed

Yan, Wenjun; Wei, Jianchao; Deng, Xufang; Shi, Zixue; Zhu, Zixiang; Shao, Donghua; Li, Beibei; Wang, Shaohui; Tong, Guangzhi; Ma, Zhiyong

2015-08-18

p53 is a tumor suppressor that contributes to the host immune response against viral infections in addition to its well-established protective role against cancer development. In response to influenza A virus (IAV) infection, p53 is activated and plays an essential role in inhibiting IAV replication. As a transcription factor, p53 regulates the expression of a range of downstream responsive genes either directly or indirectly in response to viral infection. We compared the expression profiles of immune-related genes between IAV-infected wild-type p53 (p53WT) and p53-deficient (p53KO) mice to gain an insight into the basis of p53-mediated antiviral response. p53KO and p53WT mice were infected with influenza A/Puerto Rico/8/1934 (PR8) strain. Clinical symptoms and body weight changes were monitored daily. Lung specimens of IAV-infected mice were collected for analysis of virus titers and gene expression profiles. The difference in immune-related gene expression levels between IAV-infected p53KO and p53WT mice was comparatively determined using microarray analysis and confirmed by quantitative real-time reverse transcription polymerase chain reaction. p53KO mice showed an increased susceptibility to IAV infection compared to p53WT mice. Microarray analysis of gene expression profiles in the lungs of IAV-infected mice indicated that the increased susceptibility was associated with significantly changed expression levels in a range of immune-related genes in IAV-infected p53KO mice. A significantly attenuated expression of Ifng (encoding interferon (IFN)-gamma), Irf7 (encoding IFN regulator factor 7), and antiviral genes, such as Mx2 and Eif2ak2 (encoding PKR), were observed in IAV-infected p53KO mice, suggesting an impaired IFN-mediated immune response against IAV infection in the absence of p53. In addition, dysregulated expression levels of proinflammatory cytokines and chemokines, such as Ccl2 (encoding MCP-1), Cxcl9, Cxcl10 (encoding IP-10), and Tnf, were detected

Lactoferricin but not lactoferrin inhibit herpes simplex virus type 2 infection in mice.

PubMed

Shestakov, Andrey; Jenssen, Håvard; Nordström, Inger; Eriksson, Kristina

2012-03-01

We have evaluated the potential of bovine lactoferrin and lactoferricin for their ability to prevent and/or treat genital HSV-2 infection in mice. We confirm previous data showing that both lactoferrin and lactoferricin have antiviral properties in vitro and can inhibit HSV-2 infection of GMK cells in a dose-dependent manner. When tested in vivo, lactoferricin but not lactoferrin was also a potent inhibitor of HSV-2 infection. When admixed with virus prior to inoculation, lactoferricin inhibited disease development and significantly reduced the viral load in a genital model of HSV-2 infection in mice. Lactoferrin and lactoferricin were also tested for their ability to stimulate the production of chemokines. Neither of the compounds induced the production of CCL3, CCL5, CXCL1 or CXCL2 by mouse splenocytes in vitro. However, when tested in vivo, both lactoferrin and lactoferricin were able to induce local vaginal production of CCL5. Lactoferrin also induced CXCL2 production. The prophylactic and/or therapeutic effects of lactoferrin or lactoferricin were also tested. But none of the compounds were efficient in blocking HSV-2 infection when given 24h prior to HSV-2 infection. Lactoferricin however showed promising results as a therapeutic agent and delayed both disease onset by 3days as well as reducing the viral load almost 15-fold when given as a single dose 24h post-infection. These data show that lactoferricin can block genital herpes infection in mice, and perhaps also be used for post-infection treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of acycloguanosine treatment of acute and latent herpes simplex infections in mice.

PubMed

Field, H J; Bell, S E; Elion, G B; Nash, A A; Wildy, P

1979-04-01

Systemic treatment of mice with the nucleoside analog 9-(2-hydroxyethoxymethyl)guanine (acycloguanosine [aciclovir]) was found to be highly effective against acute type 1 herpes simplex virus infection of the pinna. The drug ablated clinical signs and reduced virus replication both in tissue local to the inoculation site and within the nervous system. Provided that moderate-sized virus inocula were used, acycloguanosine treatment reduced or prevented the establishment of a latent infection in the dorsal root ganglia relating to the sensory nerve supply of the ear. However, although it aborted artificially produced infections in dorsal root ganglia, acycloguanosine was found not to be effective against the latent infection once established. This finding strongly indicated that latent herpes simplex virus in mice can exist in a nonreplicating form.

NADPH Phagocyte Oxidase Knockout Mice Control Trypanosoma cruzi Proliferation, but Develop Circulatory Collapse and Succumb to Infection

PubMed Central

Macedo, Juan P.; Utsch, Lara; Tafuri, Wagner L.; Campagnole-Santos, Maria José; Alves, Rosana O.; Alves-Filho, José C. F.; Romanha, Alvaro J.; Cunha, Fernando Queiroz; Teixeira, Mauro M.; Radi, Rafael; Vieira, Leda Q.

2012-01-01

•NO is considered to be a key macrophage-derived cytotoxic effector during Trypanosoma cruzi infection. On the other hand, the microbicidal properties of reactive oxygen species (ROS) are well recognized, but little importance has been attributed to them during in vivo infection with T. cruzi. In order to investigate the role of ROS in T. cruzi infection, mice deficient in NADPH phagocyte oxidase (gp91phox −/− or phox KO) were infected with Y strain of T. cruzi and the course of infection was followed. phox KO mice had similar parasitemia, similar tissue parasitism and similar levels of IFN-γ and TNF in serum and spleen cell culture supernatants, when compared to wild-type controls. However, all phox KO mice succumbed to infection between day 15 and 21 after inoculation with the parasite, while 60% of wild-type mice were alive 50 days after infection. Further investigation demonstrated increased serum levels of nitrite and nitrate (NOx) at day 15 of infection in phox KO animals, associated with a drop in blood pressure. Treatment with a NOS2 inhibitor corrected the blood pressure, implicating NOS2 in this phenomenon. We postulate that superoxide reacts with •NO in vivo, preventing blood pressure drops in wild type mice. Hence, whilst superoxide from phagocytes did not play a critical role in parasite control in the phox KO animals, its production would have an important protective effect against blood pressure decline during infection with T. cruzi. PMID:22348160

A role for Toll-like receptor 4 in the host response to the lung infection of Yersinia pseudotuberculosis in mice.

PubMed

Choi, Jin-A; Jeong, Yu-Jin; Kim, Jae-Eun; Kang, Min-Jung; Kim, Jee-Cheon; Oh, Sang-Muk; Lee, Kyung-Bok; Kim, Dong-Hyun; Kim, Dong-Jae; Park, Jong-Hwan

2016-02-01

Although a Yersinia pseudotuberculosis (Yptb) lung infection model has been developed to study Y. pestis pathogenesis, it is still necessary to establish a new animal model to mimic the pathophysiological features induced by Y. pestis infection. Here, we provide a new lung infection model using the Yptb strain, IP2777, which displayed rapid spread of bacteria to the liver, spleen, and blood. In addition, we examined whether TLR4 is involved in Yptb-induced pathogenesis in the lung infection model of mice we generated. Following lung infection of WT and TLR4-deficient mice with the Yptb strain IP2777, the survival rate, bacterial colonization, histopathology, and level of cytokines and chemokines in the lung, spleen, liver, and blood were analyzed. TLR4-deficient mice had a lower survival rate than WT mice in response to Yptb lung infection. Although the bacterial colonization and pathology of the lung were comparable between WT and TLR4-deficient mice, those of the spleen and liver were more severe in TLR4-deficient mice. In addition, the levels of TNF-α and CXCL2 in the liver and IL-6 and CXCL2 in the blood were higher in TLR4-deficient mice than in WT mice. Our results demonstrate that TLR4 is necessary for optimal host protection against Yptb lung infection and TLR4-deficient mice may serve as a better genetic model of Yptb infection for mimicking Y. pestis infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

CHARACTERIZATION OF A CRYPTOSPORIDIUM MURIS INFECTION AND REINFECTION IN CF-1 MICE

EPA Science Inventory

To establish control values for circulating cells and immune associated organs over the course of a self-limiting Cryptosporidium muris infection and rechallenge infection, mice were evaluated at intervals starting before oral inoculation and ending after oocyst shedding had ceas...

Z-100, a lipid-arabinomannan extracted from Mycobacterium tuberculosis, improves the resistance of thermally injured mice to herpes virus infections.

PubMed

Kobayashi, M; Herndon, D N; Pollard, R B; Suzuki, F

1994-06-01

The effect of Z-100, a lipid-arabinomannan extracted from Mycobacterium tuberculosis strain Aoyama B, was investigated on the resistance of thermally injured mice (TI-mice) to herpes simplex virus type 1 (HSV) infections. The susceptibility of TI mice to infection was about 100 times greater than it was in normal mice (N mice). However, the increased susceptibility of TI mice to infection was effectively counteracted to the levels observed in N mice when treated with Z-100 (10 mg/kg i.p.; 1, 3 and 5 days after thermal injury). Adoptive transfer of burn-associated CD8+ CD11b+ TCR gamma/delta + suppressor T (BAST) cells, prepared from TI mice, increased the susceptibility of N mice to infection by HSV, while the susceptibility of N mice, inoculated with the CD8+ T-cell fraction prepared from Z-100-treated TI mice (ZTC), to infection was not changed. In addition, the suppressor cell activity of BAST cells was not demonstrated when they were assayed in vitro in the presence of anti-IL-4 monoclonal antibody (mAb). BAST cells released IL-4 into their culture fluids without stimulation. The suppressor cell activity of ZTC and IL-4 production by ZTC were minimal. These results suggest that Z-100 may improve the resistance of TI mice to HSV infection through the regulation of BAST cells and/or the release of IL-4 from these cells.

Intranasal P particle vaccine provided partial cross-variant protection against human GII.4 norovirus diarrhea in gnotobiotic pigs.

PubMed

Kocher, Jacob; Bui, Tammy; Giri-Rachman, Ernawati; Wen, Ke; Li, Guohua; Yang, Xingdong; Liu, Fangning; Tan, Ming; Xia, Ming; Zhong, Weiming; Jiang, Xi; Yuan, Lijuan

2014-09-01

Noroviruses (NoVs) are the leading cause of nonbacterial acute gastroenteritis worldwide in people of all ages. The P particle is a novel vaccine candidate derived from the protruding (P) domain of the NoV VP1 capsid protein. This study utilized the neonatal gnotobiotic pig model to evaluate the protective efficacies of primary infection, P particles, and virus-like particles (VLPs) against NoV infection and disease and the T cell responses to these treatments. Pigs either were vaccinated intranasally with GII.4/1997 NoV (VA387)-derived P particles or VLPs or were inoculated orally with a GII.4/2006b NoV variant. At postinoculation day (PID) 28, pigs either were euthanized or were challenged with the GII.4/2006b variant and monitored for diarrhea and virus shedding for 7 days. The T cell responses in intestinal and systemic lymphoid tissues were examined. Primary NoV infection provided 83% homologous protection against diarrhea and 49% homologous protection against virus shedding, while the P particle and VLP vaccines provided cross-variant protection (47% and 60%, respectively) against diarrhea. The protection rates against diarrhea are significantly inversely correlated with T cell expansion in the duodenum and are positively correlated with T cell expansion in the ileum and spleen. The P particle vaccine primed for stronger immune responses than VLPs, including significantly higher numbers of activated CD4+ T cells in all tissues, gamma interferon-producing (IFN-γ+) CD8+ T cells in the duodenum, regulatory T cells (Tregs) in the blood, and transforming growth factor β (TGF-β)-producing CD4+ CD25- FoxP3+ Tregs in the spleen postchallenge, indicating that P particles are more immunogenic than VLPs at the same dose. In conclusion, the P particle vaccine is a promising vaccine candidate worthy of further development. The norovirus (NoV) P particle is a vaccine candidate derived from the protruding (P) domain of the NoV VP1 capsid protein. P particles can be

Comparison of Brucella abortus and Brucella melitensis infections of mice and their effect on acquired cellular resistance.

PubMed Central

Young, E J; Gomez, C I; Yawn, D H; Musher, D M

1979-01-01

By using mice infected with strains of Brucella abortus and Brucella melitensis we examined the histological responses to infection, the relationship of histology to persistence of organisms, and the relation of persistence of organisms to the acquisition of acquired cellular resistance (ACR). Infection with B. abortus resulted in well-formed granulomas in the livers, which persisted for more than 30 days. In contrast, infection with B. melitensis produced microabscesses in the livers which resolved before 30 days. The clearance of organisms from the tissues was also different. A total of 30 days after infection, large numbers of viable bacteria were recovered from the tissues of B. abortus-infected mice whereas bacteria were no longer recoverable from B. melitensis-infected animals. ACR to Listeria monocytogenes, another intracellular pathogen, persisted for more than 30 days in B. abortus-infected mice but waned rapidly in B. melitensis-infected animals. This disappearance of ACR due to B. melitensis paralleled the clearance of bacteria from the tissues. Images PMID:121113

Angiotensin II Moderately Decreases Plasmodium Infection and Experimental Cerebral Malaria in Mice.

PubMed

Gallego-Delgado, Julio; Baravian, Charlotte; Edagha, Innocent; Ty, Maureen C; Ruiz-Ortega, Marta; Xu, Wenyue; Rodriguez, Ana

2015-01-01

Angiotensin II, a peptide hormone that regulates blood pressure, has been proposed as a protective factor against cerebral malaria based on a genetic analysis. In vitro studies have documented an inhibitory effect of angiotensin II on Plasmodium growth, while studies using chemical inhibitors of angiotensin II in mice showed protection against experimental cerebral malaria but not major effects on parasite growth. To determine whether the level of angiotensin II affects Plasmodium growth and/or disease outcome in malaria, elevated levels of angiotensin II were induced in mice by intradermal implantation of osmotic mini-pumps providing constant release of this hormone. Mice were then infected with P. berghei and monitored for parasitemia and incidence of cerebral malaria. Mice infused with angiotensin II showed decreased parasitemia seven days after infection. The development of experimental cerebral malaria was delayed and a moderate increase in survival was observed in mice with elevated angiotensin II, as confirmed by decreased number of cerebral hemorrhages compared to controls. The results presented here show for the first time the effect of elevated levels of angiotensin II in an in vivo model of malaria. The decreased pathogenesis observed in mice complements a previous human genetic study, reinforcing the hypothesis of a beneficial effect of angiotensin II in malaria.

Topical resiquimod protects against visceral infection with Leishmania infantum chagasi in mice.

PubMed

Craft, Noah; Birnbaum, Ron; Quanquin, Natalie; Erfe, Marie Crisel B; Quant, Cara; Haskell, Jacquelyn; Bruhn, Kevin W

2014-09-01

New prevention and treatment strategies are needed for visceral leishmaniasis, particularly ones that can be deployed simply and inexpensively in areas where leishmaniasis is endemic. Synthetic molecules that activate Toll-like receptor 7 and 8 (TLR7/8) pathways have previously been demonstrated to enhance protection against cutaneous leishmaniasis. We initially sought to determine whether the TLR7/8-activating molecule resiquimod might serve as an effective vaccine adjuvant targeting visceral leishmaniasis caused by infection with Leishmania infantum chagasi. Resiquimod was topically applied to the skin of mice either prior to or after systemic infection with L. infantum chagasi, and parasite burdens were assessed. Surprisingly, topical resiquimod application alone, in the absence of vaccination, conferred robust resistance to mice against future intravenous challenge with virulent L. infantum chagasi. This protection against L. infantum chagasi infection persisted as long as 8 weeks after the final topical resiquimod treatment. In addition, in mice with existing infections, therapeutic treatment with topical resiquimod led to significantly lower visceral parasite loads. Resiquimod increased trafficking of leukocytes, including B cells, CD4(+) and CD8(+) T cells, dendritic cells, macrophages, and granulocytes, in livers and spleens, which are the key target organs of visceralizing infection. We conclude that topical resiquimod leads to systemic immune modulation and confers durable protection against visceralizing L. infantum chagasi infection, in both prophylactic and therapeutic settings. These studies support continued studies of TLR-modulating agents to determine mechanisms of protection and also provide a rationale for translational development of a critically needed, novel class of topical, preventative, and therapeutic agents for these lethal infections. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Topical Resiquimod Protects against Visceral Infection with Leishmania infantum chagasi in Mice

PubMed Central

Craft, Noah; Birnbaum, Ron; Quanquin, Natalie; Erfe, Marie Crisel B.; Quant, Cara; Haskell, Jacquelyn

2014-01-01

New prevention and treatment strategies are needed for visceral leishmaniasis, particularly ones that can be deployed simply and inexpensively in areas where leishmaniasis is endemic. Synthetic molecules that activate Toll-like receptor 7 and 8 (TLR7/8) pathways have previously been demonstrated to enhance protection against cutaneous leishmaniasis. We initially sought to determine whether the TLR7/8-activating molecule resiquimod might serve as an effective vaccine adjuvant targeting visceral leishmaniasis caused by infection with Leishmania infantum chagasi. Resiquimod was topically applied to the skin of mice either prior to or after systemic infection with L. infantum chagasi, and parasite burdens were assessed. Surprisingly, topical resiquimod application alone, in the absence of vaccination, conferred robust resistance to mice against future intravenous challenge with virulent L. infantum chagasi. This protection against L. infantum chagasi infection persisted as long as 8 weeks after the final topical resiquimod treatment. In addition, in mice with existing infections, therapeutic treatment with topical resiquimod led to significantly lower visceral parasite loads. Resiquimod increased trafficking of leukocytes, including B cells, CD4+ and CD8+ T cells, dendritic cells, macrophages, and granulocytes, in livers and spleens, which are the key target organs of visceralizing infection. We conclude that topical resiquimod leads to systemic immune modulation and confers durable protection against visceralizing L. infantum chagasi infection, in both prophylactic and therapeutic settings. These studies support continued studies of TLR-modulating agents to determine mechanisms of protection and also provide a rationale for translational development of a critically needed, novel class of topical, preventative, and therapeutic agents for these lethal infections. PMID:25030052

Anti-gluten immune response following Toxoplasma gondii infection in mice.

PubMed

Severance, Emily G; Kannan, Geetha; Gressitt, Kristin L; Xiao, Jianchun; Alaedini, Armin; Pletnikov, Mikhail V; Yolken, Robert H

2012-01-01

Gluten sensitivity may affect disease pathogenesis in a subset of individuals who have schizophrenia, bipolar disorder or autism. Exposure to Toxoplasma gondii is a known risk factor for the development of schizophrenia, presumably through a direct pathological effect of the parasite on brain and behavior. A co-association of antibodies to wheat gluten and to T. gondii in individuals with schizophrenia was recently uncovered, suggesting a coordinated gastrointestinal means by which T. gondii and dietary gluten might generate an immune response. Here, we evaluated the connection between these infectious- and food-based antigens in mouse models. BALB/c mice receiving a standard wheat-based rodent chow were infected with T. gondii via intraperitoneal, peroral and prenatal exposure methods. Significant increases in the levels of anti-gluten IgG were documented in all infected mice and in offspring from chronically infected dams compared to uninfected controls (repetitive measures ANOVAs, two-tailed t-tests, all p≤0.00001). Activation of the complement system accompanied this immune response (p≤0.002-0.00001). Perorally-infected females showed higher levels of anti-gluten IgG than males (p≤0.009) indicating that T. gondii-generated gastrointestinal infection led to a significant anti-gluten immune response in a sex-dependent manner. These findings support a gastrointestinal basis by which two risk factors for schizophrenia, T. gondii infection and sensitivity to dietary gluten, might be connected to produce the immune activation that is becoming an increasingly recognized pathology of psychiatric disorders.

Effect of the bradykinin 1 receptor antagonist SSR240612 after oral administration in Mycobacterium tuberculosis-infected mice.

PubMed

Rodrigues-Junior, Valnês S; Pail, Priscilla B; Villela, Anne D; Falcão, Virgínia C A; Dadda, Adílio S; Abbadi, Bruno L; Pesquero, João B; Santos, Diógenes S; Basso, Luiz A; Campos, Maria M

2018-03-01

The role, if any, played by the kinin system in tuberculosis infection models, either in vivo or in vitro, was investigated. The effects of Mycobacterium tuberculosis infection on C57BL/6 wild type, B 1 R-/-, B 2 R-/- and double B 1 R/B 2 R knockout mice were evaluated. Immunohistochemistry analysis was carried out to assess B 1 R and B 2 R expression in spleens and lungs of M. tuberculosis-infected mice. In addition, in vitro experiments with M. tuberculosis-infected macrophages were performed. The in vivo effects of HOE-140 and SSR240612 on the mice model of infection were also evaluated. Infected B 2 R-/- mice exhibited increased splenomegaly, whereas decreased spleen weight in infected double B 1 R/B 2 R knockout mice was observed. The bacterial load, determined as colony-forming units, did not differ in the spleens and lungs of the studied mouse strains. Importantly, immunohistochemical analysis revealed that B 1 R was upregulated in both spleens and lungs of infected mice. M. tuberculosis-infected macrophages incubated with SSR240612, alone or in combination with des-Arg 9 -BK, for four days, displayed a marked inhibitory effect on CFU counts. However, the pre-incubation of the selective B 1 R (des-Arg 9 -BK and SSR240612) and B 2 R (BK and HOE-140) agonists and antagonists, respectively, did not significantly affect the bacterial loads. A statistically significant reduction in the CFU of M. tuberculosis in lungs and spleens of animals treated with SSR240612, but not with HOE-140, was observed. Further efforts should be pursued to clarify whether or not SSR240612 might be considered an option for the treatment of tuberculosis. Copyright © 2018. Published by Elsevier Ltd.

Saccharomyces cerevisiae expressing Gp43 protects mice against Paracoccidioides brasiliensis infection.

PubMed

Assis-Marques, Mariana Aprigio; Oliveira, Aline Ferreira; Ruas, Luciana Pereira; dos Reis, Thaila Fernanda; Roque-Barreira, Maria Cristina; Coelho, Paulo Sergio Rodrigues

2015-01-01

The dimorphic fungus Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis (PCM). It is believed that approximately 10 million people are infected with the fungus and approximately 2% will eventually develop the disease. Unlike viral and bacterial diseases, fungal diseases are the ones against which there is no commercially available vaccine. Saccharomyces cerevisiae may be a suitable vehicle for immunization against fungal infections, as they require the stimulation of different arms of the immune response. Here we evaluated the efficacy of immunizing mice against PCM by using S. cerevisiae yeast expressing gp43. When challenged by inoculation of P. brasiliensis yeasts, immunized animals showed a protective profile in three different assays. Their lung parenchyma was significantly preserved, exhibiting fewer granulomas with fewer fungal cells than found in non-immunized mice. Fungal burden was reduced in the lung and spleen of immunized mice, and both organs contained higher levels of IL-12 and IFN-γ compared to those of non-vaccinated mice, a finding that suggests the occurrence of Th1 immunity. Taken together, our results indicate that the recombinant yeast vaccine represents a new strategy to confer protection against PCM.

Effect of Acycloguanosine Treatment on Acute and Latent Herpes Simplex Infections in Mice

PubMed Central

Field, Hugh J.; Bell, Susanne E.; Elion, Gertrude B.; Nash, Anthony A.; Wildy, Peter

1979-01-01

Systemic treatment of mice with the nucleoside analog 9-(2-hydroxyethoxymethyl)guanine (acycloguanosine [aciclovir]) was found to be highly effective against acute type 1 herpes simplex virus infection of the pinna. The drug ablated clinical signs and reduced virus replication both in tissue local to the inoculation site and within the nervous system. Provided that moderate-sized virus inocula were used, acycloguanosine treatment reduced or prevented the establishment of a latent infection in the dorsal root ganglia relating to the sensory nerve supply of the ear. However, although it aborted artificially produced infections in dorsal root ganglia, acycloguanosine was found not to be effective against the latent infection once established. This finding strongly indicated that latent herpes simplex virus in mice can exist in a nonreplicating form. PMID:464587

Immunological effects of the orally administered neuraminidase inhibitor oseltamivir in influenza virus-infected and uninfected mice.

PubMed

Burger, R A; Billingsley, J L; Huffman, J H; Bailey, K W; Kim, C U; Sidwell, R W

2000-04-01

Oseltamivir (GS4104), the ethyl ester prodrug of the carbocyclic transition state sialic acid analog GS4071, has been reported to be a striking inhibitor of influenza A and B virus infections in mice and ferrets. Multiple studies indicate this material to also be active against the disease in humans, and it has recently been approved for human use. The effect of oral gavage (p.o.) therapy of oseltamivir on various immune factors considered to be of importance in primary influenza virus infection was studied in mice. Both uninfected animals and those infected with influenza A/NWS/33 (H1N1) virus were used. Doses of 100 mg kg(-1) day(-1) were administered twice daily for 5 days beginning 16 h pre-virus exposure. Two hours after end of treatment, the mice were killed and their spleens assayed for cytotoxic T lymphocyte (CTL) and natural killer (NK) cell activity. Subpopulations of splenic T, T-helper, T-cytotoxic and B lymphocytes as well as macrophages were determined using flow cytometry. Similar significant (P<0.01) increases in CTL activity were seen at effector:target cell ratios of 60:1 and 30:1 in the infected mice treated with oseltamivir or with placebo. NK cell activity was greater in the infected mice than in uninfected mice; the levels in all animals were not significantly affected by treatment with oseltamivir. Macrophage, T, T-helper, T-cytotoxic and B lymphocyte populations were similar in both treated and untreated animals. These data indicate treatment with oseltamivir does not adversely affect the primary in vivo cellular immune responses to influenza virus infection assayed in this study. The experiment was repeated to show that treatment with this compound significantly prevented the development of the infection and inhibited virus titers in the lung. Surviving treated mice on day 21 had mean neutralizing antibody titers of 1:208, and withstood rechallenge with the virus at this time, indicating the initial virus-inhibitory effect also did not

Interactions between mefloquine and the anti-fibrotic drug silymarin on Schistosoma mansoni infections in mice.

PubMed

Kamel, Reem O A

2016-11-01

The present study tests the anti-inflammatory and anti-fibrotic effects of silymarin alone or combined with mefloquine on acute schistosomiasis by evaluating parasitological, histopathological, biochemical and immunological parameters. Male CDI Swiss mice were divided into seven groups, which included healthy controls, mice infected with Schistosoma mansoni or treated with silymarin (140 mg/kg body weight) or mefloquine (400 mg/kg body weight), or mice treated with a combination of both drugs and uninfected mice simply treated with mefloquine or silymarin alone. All mouse groups were sacrificed 8 weeks post-infection (pi) and/or post-treatment. Those infected mice treated with both silymarin and mefloquine showed a significant decrease (P <  0.001) in worm burden, immunoglobulins (IgG and IgM), liver function enzymes and granuloma diameter, with complete eradication of immature and mature eggs. In conclusion, treatment with silymarin combined with mefloquine in murine schistosomiasis was able to reduce granulomatous reactions and hepatic fibrosis. Hence, this combination is a new strategy to be studied as an efficient tool in the treatment of schistosomal liver fibrosis.

THE EFFECT OF DINITROPHENOL AND THYROXIN ON THE SUSCEPTIBILITY OF MICE TO STAPHYLOCOCCAL INFECTIONS

PubMed Central

Smiths, J. Maclean; Dubos, René J.

1956-01-01

Mice were given daily per os amounts of dinitrophenol or of thyroid extract sufficient to prevent or retard the normal weight gain of uninfected animals, but not large enough to cause their death. When mice maintained on these regimens for 1 or 2 weeks were infected with staphylococci, most of them died within 12 days—much more rapidly than did mice fed a normal diet. Deaths occurred even when the organism injected was a non-virulent staphylococcus, unable to cause fatal disease in mice fed a normal diet. There was some suggestion that thyroid treatment interfered with the bactericidal mechanism in the liver, spleen, and kidneys of mice during the initial phase of infection. In contrast there was no clear evidence at any time thereafter that either thyroid extract or dinitrophenol caused the staphylococci to multiply more rapidly in the various organs. PMID:13278459

Immune response in mice infected with Candida albicans in the mycelial form.

PubMed

Bibas Bonet de Jorrat, M E; de Valdez, G A; de Petrino, S F; Sirena, A; Perdigón, G

1989-05-01

The effect of the infection with the mycelial form of a Candida albicans strain (Mycology Dept.) upon the immune system in mice was studied. BALB/c mice were infected intraperitoneally in a single dose of a 3 x 10(6), 6 x 10(6) and 12 x 10(6) cell suspension of the strain. Macrophages's activity was studied the days 7, 14, 21, 28, 35, and 42 after inoculation, by the following assays: phagocytosis in vitro, mononucleated phagocytic system by the colloidal carbon clearance technique, the lymphocyte's activity by the direct plaque forming cells technique (PFC) and delayed hypersensitivity (DTH). Infection with the mycelial form did not affect the peritoneal macrophage's phagocytic ability, neither modified the delayed hypersensitivity to sheep red blood cells (SRBC). However, a slight and transient depression of the lymphocyte stimulation was found. Suppression of PFC to SRBC was high when a 12 x 10(6) cell suspension was used in contrast to the infection with blastospores. These results suggest that systemic infection by Candida albicans in its mycelial form do not induce a non specific immunosuppression.

Prevalence of Murine Helicobacter spp. Infection Is Reduced by Restocking Research Colonies with Helicobacter-Free Mice

PubMed Central

Lofgren, Jennifer LS; Esmail, Michael; Mobley, Melissa; McCabe, Amanda; Taylor, Nancy S; Shen, Zeli; Erdman, Susan; Hewes, Christine; Whary, Mark T; Fox, James G

2012-01-01

Most academic research colonies of mice are endemically infected with enterohepatic Helicobacter spp. (EHS). We evaluated EHS prevalence in surveillance mice before and after a 10-y period of requiring that imported mice be free of EHS by embryo transfer rederivation or purchase from approved vendors. In 2009, composite fecal samples from CD1 surveillance mice representing colony health in 57 rooms located in 6 facilities were evaluated for EHS infection by using PCR assays. Fecal samples were screened with primers designed to detect all known EHS, and positive samples were further assayed by using primers specific for H. hepaticus, H. bilis, H. rodentium, and H. typhlonicus. Most EHS were detected in surveillance mice within the first month of dirty bedding exposure, with prevalence ranging from 0% to 64% as monoinfections or, more commonly, infections with multiple EHS. Compared with 1999 prevalence data, EHS remained endemic in colonies importing the lowest number of EHS-free mice. EHS were absent or the prevalence was greatly reduced in colonies receiving the highest percentage of EHS-free mice. This study demonstrates that the management decision to require exclusive importation of EHS-free mice reduced EHS prevalence on an institutional scale without intensive labor and expense associated with other techniques or interference with research objectives. PMID:23043808

Alterations in metabolic pathways in stomach of mice infected with Helicobacter pylori.

PubMed

Nishiumi, Shin; Yoshida, Masaru; Azuma, Takeshi

2017-08-01

Numerous studies of Helicobacter pylori (H. pylori) have been performed, but few studies have evaluated the effects of H. pylori infections using metabolome analysis, which involves the comprehensive study of low molecular weight metabolites. In this study, the metabolites in the stomach tissue of mice that had been infected with H. pylori SS1 for 1, 3, or 6 months were analyzed, and then evaluations of various metabolic pathways were performed to gain novel understandings of H. pylori infections. As a result, it was found that the glycolytic pathway, the tricarboxylic acid cycle, and the choline pathway tended to be upregulated at 1 month after the H. pylori SS1 infection. The urea cycle tended to be downregulated at 6 months after the infection. High levels of some amino acids were observed in the stomach tissue of the H. pylori SS1-infected mice at 1 month after the infection, whereas low levels of many amino acids were detected at 3 and 6 months after the infection. These results suggest that H. pylori infection causes various metabolic alterations at lesional sites, and these alterations might be linked to the crosstalk between H. pylori and the host leading to transition of disease conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cocaine-mediated impact on HIV infection in humanized BLT mice

PubMed Central

Kim, Sohn G.; Lowe, Emily L.; Dixit, Dhaval; Seyeon Youn, Cindy; Kim, Irene J.; Jung, James B.; Rovner, Robert; Zack, Jerome A.; Vatakis, Dimitrios N.

2015-01-01

Cocaine abuse has been shown to have broad-ranging effects on human immunity. With regards to HIV infection, in vitro studies have shown that cocaine enhances infection of stimulated lymphocytes. Moreover, cohort studies in the pre- and post-HAART era have linked stimulant abuse with increased HIV pathogenesis. The latter data, however, have been undermined by a series of confounding factors underscoring the importance of controlled in vivo models to fully assess the impact of cocaine use and abuse on HIV infection and pathogenesis. Here, we have infected humanized mice with HIV-1 following acute cocaine exposure to assess the impact on infection. Stimulant exposure resulted in increased inflammatory cytokine expression, accelerated HIV infection, while blunting effector function of cytotoxic T lymphocytes. These data demonstrate cocaine’s multifactorial impact on HIV infection that extends beyond high-risk behavior. PMID:26084721

The lack of RNA-dependent protein kinase enhances susceptibility of mice to genital herpes simplex virus type 2 infection

PubMed Central

Carr, Daniel J J; Wuest, Todd; Tomanek, Lisa; Silverman, Robert H; Williams, Bryan R G

2006-01-01

Mice deficient in RNA-dependent protein kinase (PKR–/–) or deficient in PKR and a functional 2′,5′-oligoadenylate synthetase (OAS) pathway (PKR/RL–/–) are more susceptible to genital herpes simplex virus type 2 (HSV-2) infection than wild-type mice or mice that are deficient only in a functional OAS pathway (RL–/–) as measured by survival over 30 days. The increase in susceptibility correlated with an increase in virus titre recovered from vaginal tissue or brainstem of infected mice during acute infection. There was also an increase in CD45+ cells and CD8+ T cells residing in the central nervous system of HSV-2-infected PKR/RL–/– mice in comparison with RL–/– or wild-type control animals. In contrast, there was a reduction in the HSV-specific CD8+ T cells within the draining lymph node of the PKR/RL–/– mice. Collectively, activation of PKR, but not of OAS, contributes significantly to the local control and spread of HSV-2 following genital infection. PMID:16895559

Effects of Fuzhuan Brick-Tea Water Extract on Mice Infected with E. coli O157:H7

PubMed Central

Wang, Yuanliang; Xu, Aiqing; Liu, Ping; Li, Zongjun

2015-01-01

Fuzhuan brick-tea extract (FBTE) affects the physiology of mice infected with Escherichia coli O157:H7. For 10 consecutive days, 0.05, 0.5, and 1.0 g/mL FBTE was administered intragastrically to three groups of infected Kunming mice, and changes in immunological function, hematology, and histopathology were examined. The results revealed upregulation of platelets, total protein, and albumin along with downregulation of serum triglycerides, aspartate aminotransferase, creatinine, and urea nitrogen in FBTE-treated mice. Histological sections of stomach, kidney, duodenum, ileum, and colon suggested that infected mucous membranes could be rehabilitated by low- and high-dose FBTE and that inflammation was alleviated. Similarly, increased thymic function in mice treated with middle- and high-dose FBTE led to elevated serum hemolysin antibody titer and increased CD4+ and CD8+ T cells, as indicated by CD4+ and CD8+ expression on intestinal mucosa. Monocyte and macrophage function was improved by three FBTE dosages tested. Colonic microbiota analysis by denaturing gradient gel electrophoresis (DGGE) revealed characteristic bands in infected mice treated with middle- and high-dose FBTE and increased species diversity in Lactobacillus, Bacteroides, and Clostridium cluster IV. These results suggest that FBTE may protect kidney and liver of mice infected with E. coli O157:H7, improve immune function, and regulate the colonic microbiota. PMID:26140539

Toxoplasma gondii oral infection induces intestinal inflammation and retinochoroiditis in mice genetically selected for immune oral tolerance resistance.

PubMed

Dias, Raul Ramos Furtado; Carvalho, Eulógio Carlos Queiroz de; Leite, Carla Cristina da Silva; Tedesco, Roberto Carlos; Calabrese, Katia da Silva; Silva, Antonio Carlos; DaMatta, Renato Augusto; de Fatima Sarro-Silva, Maria

2014-01-01

Toxoplasmosis is a worldwide disease with most of the infections originating through the oral route and generates various pathological manifestations, ranging from meningoencephalitis to retinochoroiditis and inflammatory bowel disease. Animal models for these pathologies are scarce and have limitations. We evaluated the outcome of Toxoplasma gondii oral infection with 50 or 100 cysts of the ME-49 strain in two lines of mice with extreme phenotypes of susceptibility (TS) or resistance (TR) to immune oral tolerance. Therefore, the aim of this study was to evaluate the behaviour of TS and TR mice, orally infected by T. gondii, and determine its value as a model for inflammatory diseases study. Mortality during the acute stage of the infection for TR was 50% for both dosages, while 10 and 40% of the TS died after infection with these respective dosages. In the chronic stage, the remaining TS succumbed while TR survived for 90 days. The TS displayed higher parasite load with lower intestinal inflammation and cellular proliferation, notwithstanding myocarditis, pneumonitis and meningoencephalitis. TR presented massive necrosis of villi and crypt, comparable to inflammatory bowel disease, with infiltration of lymphoid cells in the lamina propria of the intestines. Also, TR mice infected with 100 cysts presented intense cellular infiltrate within the photoreceptor layer of the eyes, changes in disposition and morphology of the retina cell layers and retinochoroiditis. During the infection, high levels of IL-6 were detected in the serum of TS mice and TR mice presented high amounts of IFN-γ and TNF-α. Both mice lineages developed different disease outcomes, but it is emphasized that TR and TS mice presented acute and chronic stages of the infection, demonstrating that the two lineages offer an attractive model for studying toxoplasmosis.

Toxoplasma gondii Oral Infection Induces Intestinal Inflammation and Retinochoroiditis in Mice Genetically Selected for Immune Oral Tolerance Resistance

PubMed Central

Dias, Raul Ramos Furtado; de Carvalho, Eulógio Carlos Queiroz; Leite, Carla Cristina da Silva; Tedesco, Roberto Carlos; Calabrese, Katia da Silva; Silva, Antonio Carlos; DaMatta, Renato Augusto; de Fatima Sarro-Silva, Maria

2014-01-01

Toxoplasmosis is a worldwide disease with most of the infections originating through the oral route and generates various pathological manifestations, ranging from meningoencephalitis to retinochoroiditis and inflammatory bowel disease. Animal models for these pathologies are scarce and have limitations. We evaluated the outcome of Toxoplasma gondii oral infection with 50 or 100 cysts of the ME-49 strain in two lines of mice with extreme phenotypes of susceptibility (TS) or resistance (TR) to immune oral tolerance. Therefore, the aim of this study was to evaluate the behaviour of TS and TR mice, orally infected by T. gondii, and determine its value as a model for inflammatory diseases study. Mortality during the acute stage of the infection for TR was 50% for both dosages, while 10 and 40% of the TS died after infection with these respective dosages. In the chronic stage, the remaining TS succumbed while TR survived for 90 days. The TS displayed higher parasite load with lower intestinal inflammation and cellular proliferation, notwithstanding myocarditis, pneumonitis and meningoencephalitis. TR presented massive necrosis of villi and crypt, comparable to inflammatory bowel disease, with infiltration of lymphoid cells in the lamina propria of the intestines. Also, TR mice infected with 100 cysts presented intense cellular infiltrate within the photoreceptor layer of the eyes, changes in disposition and morphology of the retina cell layers and retinochoroiditis. During the infection, high levels of IL-6 were detected in the serum of TS mice and TR mice presented high amounts of IFN-γ and TNF-α. Both mice lineages developed different disease outcomes, but it is emphasized that TR and TS mice presented acute and chronic stages of the infection, demonstrating that the two lineages offer an attractive model for studying toxoplasmosis. PMID:25437299

Treatment of trypanosome-infected mice with exogenous interferon, interferon inducers, or antibody to interferon

NASA Technical Reports Server (NTRS)

Degee, Antonie L. W.; Mansfield, John M.; Sonnenfeld, Gerald

1986-01-01

Earlier studies have demonstrated that mice resistant to Trypanosoma brucei rhodesiense (the B10.BR/SgSnJ strain) produces, upon infection by this parasite, two peaks of serum interferon (IFN), while the susceptible mice (C3HeB/FeJ) produces no IFN. In the present study, survival times were compared for B10.BR/SgSnJ, C3HeB/FeJ, and CBA/J (an intermediately resistant strain) mice that were injected, prior to infection with the parasite, with either of the following three preparations (1) IFN-gamma, (2) an antibody to IFN-gamma and (3) polyriboinosinic-polyribocytidylic acid (to induce IFN-alpha/beta). No effect on the survival times of mice by any of these preparations could be demonstrated, contrary to some previous reports.

Effect of Infection Duration on Habitat Selection and Morphology of Adult Echinostoma caproni (Digenea: Echinostomatidae) in ICR Mice.

PubMed

Platt, Thomas R; Zelmer, Derek A

2016-02-01

The course of infection of Echinostoma caproni was followed in female ICR mice, a permissive laboratory host, from infection to natural termination. Twenty-one mice were infected with 20 metacercariae via oral intubation and housed 3 per cage. Three mice from a randomly selected cage were necropsied at 1 mo intervals. A second group of 15 mice was infected approximately 1 yr later to replace mice negative at necropsy in the first group. Mice in the second group were examined weekly for the presence of eggs in the feces. Mice negative for eggs on consecutive days were killed and necropsied. The location of individual worms and worm clusters were located in 20 segments of the small intestine. Adult worms were killed and fixed in hot formalin, stained, and prepared as whole mounts. Standard measurements were taken using a compound microscope fitted with an ocular micrometer. The infection spontaneously resolved in 10 mice from 7 to 32 wk PI, indicating the host response is highly variable and extending the maximum recorded length of E. caproni infections in ICR mice to 31 wk. A moribund worm was found in the feces of an animal that continued to pass eggs for an additional 2 mo indicating individual variation in worm responses. Worms located preferentially in the ileum (segments 11-13) during the first 3 mo of the infection but shifted to the jejunum (segments 8-9) during weeks 4-6. Morphologically, worms of different ages clustered together in multivariate space, with substantial overlap between the 3- and 4-mo-old infrapopulations and between the 5- and 6-mo-old infrapopulations. Muscular structures increased in size throughout the experiment, while the gonads increased in size for the first 3 mo and then declined during the last 3 mo. The relationship between E. caproni and ICR mice is more nuanced than previously reported. The reduction in gonad size and the shift from the ileum to the jejunum in the last 3 mo likely are related. These changes might be attributable

Crimean-Congo hemorrhagic fever virus infection is lethal for adult type I interferon receptor-knockout mice.

PubMed

Bereczky, Sándor; Lindegren, Gunnel; Karlberg, Helen; Akerström, Sara; Klingström, Jonas; Mirazimi, Ali

2010-06-01

Crimean-Congo hemorrhagic fever virus (CCHFV) poses a great threat to public health due to its high mortality, transmission and geographical distribution. To date, there is no vaccine or specific treatment available and the knowledge regarding its pathogenesis is highly limited. Using a small-animal model system, this study showed that adult mice missing the type I interferon (IFN) receptor (IFNAR(-/-)) were susceptible to CCHFV and developed an acute disease with fatal outcome. In contrast, infection of wild-type mice (129 Sv/Ew) was asymptomatic. Viral RNA was found in all analysed organs of the infected mice, but the amount of CCHFV RNA was significantly higher in the IFNAR(-/-) mice than in the wild-type mice. Furthermore, the liver of IFNAR(-/-) mice was enlarged significantly, showing that IFN is important for limiting virus spread and protecting against liver damage in mice.

Detection of Corynebacterium bovis infection in athymic nude mice from a research animal facility in Korea.

PubMed

Kim, Tae-Hyoun; Kim, Dong-Su; Han, Ju-Hee; Chang, Seo-Na; Kim, Kyung-Sul; Seok, Seung-Hyeok; Kim, Dong-Jae; Park, Jong-Hwan; Park, Jae-Hak

2014-12-01

Corynebacterium (C.) bovis infection in nude mice causes hyperkeratosis and weight loss and has been reported worldwide but not in Korea. In 2011, nude mice from an animal facility in Korea were found to have white flakes on their dorsal skin. Histopathological testing revealed that the mice had hyperkeratosis and Gram-positive bacteria were found in the skin. We identified isolated bacteria from the skin lesions as C. bovis using PCR and 16S rRNA sequencing. To the best of our knowledge, this is the first report of C. bovis infection in nude mice from Korea.

Protective Effect of Moderate Exercise for BALB/c Mice with Salmonella Typhimurium Infection.

PubMed

Campos-Rodríguez, R; Godínez-Victoria, M; Arciniega-Martínez, I M; Reséndiz-Albor, A A; Reyna-Garfias, H; Cruz-Hernández, T R; Drago-Serrano, M E

2016-01-01

Moderate exercise enhances resistance to pathogen-associated infections. However, its influence on intestinal IgA levels and resistance to Salmonella typhimurium in mice has not been reported. The aim of this study was to assess the impact of moderate exercise on bacterial resistance and the intestinal-IgA response in a murine typhoid model. Sedentary and exercised (under a protocol of moderate swimming) BALB/c mice were orally infected with Salmonella typhimurium and sacrificed on days 7 or 14 post-infection (n=5 per group). Compared with infected sedentary mice, infected exercised animals had i) lower intestinal and systemic bacterial loads; ii) higher total and specific intestinal-IgA levels, iii) a higher percentage of IgA plasma cells in lamina propria; iv) a higher level on day 7 and lower level on day 14 of intestinal α- and J-chain mRNA and plasma corticosterone, v) unchanged mRNA expression of intestinal pIgR, and vi) a higher mRNA expression of liver pIgR, α-chain and J-chain on day 7. Hence, it is likely that an increase in corticosterone levels (stress response) induced by moderate exercise increased intestinal IgA levels by enabling greater liver expression of pIgR mRNA, leading to a rise in IgA transcytosis from the liver to intestine. The overall effect of these changes is an enhanced resistance to infection. © Georg Thieme Verlag KG Stuttgart · New York.

Pathogenesis of Lassa fever virus infection: I. Susceptibility of mice to recombinant Lassa Gp/LCMV chimeric virus.

PubMed

Lee, Andrew M; Cruite, Justin; Welch, Megan J; Sullivan, Brian; Oldstone, Michael B A

2013-08-01

Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generation of virus-specific CD8(+) T cells and clearance of the infection. Inoculation of newborn mice with rLCMV Cl13/LASV Gp resulted in a life-long persistent infection. Interestingly, adoptive transfer of rLCMV Cl13/LASV Gp immune memory cells into such persistently infected mice failed to purge virus but, in contrast, cleared virus from mice persistently infected with wt LCMV Cl13. Copyright © 2013 Elsevier Inc. All rights reserved.

Anti-Gluten Immune Response following Toxoplasma gondii Infection in Mice

PubMed Central

Severance, Emily G.; Kannan, Geetha; Gressitt, Kristin L.; Xiao, Jianchun; Alaedini, Armin; Pletnikov, Mikhail V.; Yolken, Robert H.

2012-01-01

Gluten sensitivity may affect disease pathogenesis in a subset of individuals who have schizophrenia, bipolar disorder or autism. Exposure to Toxoplasma gondii is a known risk factor for the development of schizophrenia, presumably through a direct pathological effect of the parasite on brain and behavior. A co-association of antibodies to wheat gluten and to T. gondii in individuals with schizophrenia was recently uncovered, suggesting a coordinated gastrointestinal means by which T. gondii and dietary gluten might generate an immune response. Here, we evaluated the connection between these infectious- and food-based antigens in mouse models. BALB/c mice receiving a standard wheat-based rodent chow were infected with T. gondii via intraperitoneal, peroral and prenatal exposure methods. Significant increases in the levels of anti-gluten IgG were documented in all infected mice and in offspring from chronically infected dams compared to uninfected controls (repetitive measures ANOVAs, two-tailed t-tests, all p≤0.00001). Activation of the complement system accompanied this immune response (p≤0.002–0.00001). Perorally-infected females showed higher levels of anti-gluten IgG than males (p≤0.009) indicating that T. gondii-generated gastrointestinal infection led to a significant anti-gluten immune response in a sex-dependent manner. These findings support a gastrointestinal basis by which two risk factors for schizophrenia, T. gondii infection and sensitivity to dietary gluten, might be connected to produce the immune activation that is becoming an increasingly recognized pathology of psychiatric disorders. PMID:23209841

Lymphotoxin Alpha-Deficient Mice Clear Persistent Rotavirus Infection after Local Generation of Mucosal IgA

PubMed Central

Lopatin, Uri; Blutt, Sarah E.; Conner, Margaret E.

2013-01-01

Rotavirus is a major cause of pediatric diarrheal illness worldwide. To explore the role of organized intestinal lymphoid tissues in infection by and immunity to rotavirus, lymphotoxin alpha-deficient (LTα−/−) mice that lack Peyer's patches and mesenteric lymph nodes were orally infected with murine rotavirus. Systemic rotavirus was cleared within 10 days in both LTα−/− and wild-type mice, and both strains developed early and sustained serum antirotavirus antibody responses. However, unlike wild-type mice, which resolved the intestinal infection within 10 days, LTα−/− mice shed fecal virus for approximately 50 days after inoculation. The resolution of fecal virus shedding occurred concurrently with induction of intestinal rotavirus-specific IgA in both mouse strains. Induction of intestinal rotavirus-specific IgA in LTα−/− mice correlated with the (late) appearance of IgA-producing plasma cells in the small intestine. This, together with the absence of rotavirus-specific serum IgA, implies that secretory rotavirus-specific IgA was produced locally. These findings indicate that serum IgG responses are insufficient and imply that local intestinal IgA responses are important for the clearance of rotavirus from intestinal tissues. Furthermore, they show that while LTα-dependent lymphoid tissues are important for the generation of IgA-producing B cells in the intestine, they are not absolutely required in the setting of rotavirus infection. Moreover, the induction of local IgA-producing B cell responses can occur late after infection and in an LTα-independent manner. PMID:23097456

Role of capsule and suilysin in mucosal infection of complement-deficient mice with Streptococcus suis.

PubMed

Seitz, Maren; Beineke, Andreas; Singpiel, Alena; Willenborg, Jörg; Dutow, Pavel; Goethe, Ralph; Valentin-Weigand, Peter; Klos, Andreas; Baums, Christoph G

2014-06-01

Virulent Streptococcus suis serotype 2 strains are invasive extracellular bacteria causing septicemia and meningitis in piglets and humans. One objective of this study was to elucidate the function of complement in innate immune defense against S. suis. Experimental infection of wild-type (WT) and C3(-/-) mice demonstrated for the first time that the complement system protects naive mice against invasive mucosal S. suis infection. S. suis WT but not an unencapsulated mutant caused mortality associated with meningitis and other pathologies in C3(-/-) mice. The capsule contributed also substantially to colonization of the upper respiratory tract. Experimental infection of C3(-/-) mice with a suilysin mutant indicated that suilysin expression facilitated an early disease onset and the pathogenesis of meningitis. Flow cytometric analysis revealed C3 antigen deposition on the surface of ca. 40% of S. suis WT bacteria after opsonization with naive WT mouse serum, although to a significantly lower intensity than on the unencapsulated mutant. Ex vivo multiplication in murine WT and C3(-/-) blood depended on capsule but not suilysin expression. Interestingly, S. suis invasion of inner organs was also detectable in C5aR(-/-) mice, suggesting that chemotaxis and activation of immune cells via the anaphylatoxin receptor C5aR is, in addition to opsonization, a further important function of the complement system in defense against mucosal S. suis infection. In conclusion, we unequivocally demonstrate here the importance of complement against mucosal S. suis serotype 2 infection and that the capsule of this pathogen is also involved in escape from complement-independent immunity.

Cytotoxic cells induced after Chlamydia psittaci infection in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lammert, J.K.

1982-03-01

The ability of spleen cells from Chlamydia psittaci-infected mice to lyse C. psittaci-infected and uninfected target cell monolayers was studied. The cytotoxicity assay used was a terminal label method in which the number of adherent target cells surviving the interaction with effector cells was determined by measuring the uptake of (3H)uridine by such cells. It was observed that in the first few days postinfection (3 to 5), spleens contained cells that lysed infected and uninfected targets with equal efficiency. Subsequently, infected targets were killed primarily. The activity of effector spleen cells for infected targets continued, although at a reduced level,more » beyond 21 days postinfection. Intact effector cells were required since a disruption by sonication resulted in a loss of cytotoxicity. The enhanced killing observed with infected targets was also observed when target cells were sensitized with heat- or UV-inactivated C. psittaci. This study suggests that the induction of cytotoxic cells after C. psittaci infection may contribute to the ability of the host to control multiplication of the microorganism.« less

Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

PubMed

Fitzgerald, R J; Adams, B O; Sandham, H J; Abhyankar, S

1989-03-01

A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.

Broad protection against influenza infection by vectored immunoprophylaxis in mice

PubMed Central

Balazs, Alejandro B.; Bloom, Jesse D.; Hong, Christin M.; Rao, Dinesh S.; Baltimore, David

2014-01-01

Neutralizing antibodies that target epitopes conserved among many strains of influenza virus have been recently isolated from humans. Here we demonstrate that adeno-associated viruses (AAV) encoding two such broadly neutralizing antibodies are protective against diverse influenza strains. Serum from mice that received a single intramuscular AAV injection efficiently neutralized all H1, H2 and H5 influenza strains tested. After infection with diverse strains of H1N1 influenza, treated mice showed minimal weight loss and lung inflammation. Protection lasted for at least 11 months after AAV injection. Notably, even immunodeficient and older mice were protected by this method, suggesting that expression of a monoclonal antibody alone is sufficient to protect mice from illness. If translated to humans, this prophylactic approach may be uniquely capable of protecting immunocompromised or elderly patient populations not reliably protected by existing vaccines. PMID:23728362

Resistance of chemokine receptor 6-deficient mice to Yersinia enterocolitica infection: evidence of defective M-cell formation in vivo.

PubMed

Westphal, Sabine; Lügering, Andreas; von Wedel, Julia; von Eiff, Christof; Maaser, Christian; Spahn, Thomas; Heusipp, Gerhard; Schmidt, M Alexander; Herbst, Hermann; Williams, Ifor R; Domschke, Wolfram; Kucharzik, Torsten

2008-03-01

M cells, specialized cells within Peyer's patches (PPs), are reduced in number in chemokine receptor 6 (CCR6)-deficient mice. The pathogenic microorganism Yersinia enterocolitica exploits M cells for the purpose of mucosal tissue invasion exclusively through PPs. The aim of this study was to evaluate the course of yersiniosis in CCR6-deficient mice and to investigate whether these mice might be used as an in vivo model to determine M-cell function. After oral challenge with Y. enterocolitica, control mice suffered from lethal septic infection whereas CCR6-deficient mice showed very limited symptoms of infection. Immunohistochemical analysis demonstrated PP invasion by Y. enterocolitica in control mice whereas no bacteria could be found in CCR6-deficient mice. In addition, a significant induction of proinflammatory cytokines could be found in control mice whereas proinflammatory cytokine levels in CCR6-deficient mice remained unchanged. In contrast, intraperitoneal infection resulted in severe systemic yersiniosis in both mouse groups. Abrogated oral Y. enterocolitica infection in CCR6-deficient mice demonstrates the importance of CCR6 expression in the physiological and pathological immune responses generated within PPs by influencing M-cell differentiation, underscoring the important role of M cells in the process of microbial uptake. CCR6-deficient mice may therefore represent a suitable model for the study of M-cell function in vivo.

Toxoplasma gondii infection inhibits Th17-mediated spontaneous development of arthritis in interleukin-1 receptor antagonist-deficient mice.

PubMed

Washino, Takuya; Moroda, Masataka; Iwakura, Yoichiro; Aosai, Fumie

2012-04-01

Interleukin 1 receptor antagonist (IL-1Ra)-deficient BALB/c mice develop spontaneous arthritis resembling human rheumatoid arthritis. We herein report that infection with Toxoplasma gondii, an intracellular protozoan, is capable of ameliorating the spontaneous development of arthritis in IL-1Ra-deficient mice. The onset of arthritis development was delayed and the severity score of arthritis was significantly suppressed in T. gondii-infected mice. Expression of IL-12p40 mRNA from CD11c(+) cells of mesenteric lymph nodes (mLN) and spleen markedly increased at 1 week after peroral infection. While CD11c(+) cells also produced IL-10, IL-1β, and IL-6, CD4(+) T cells from T. gondii-infected mice expressed significantly high levels of T-bet and gamma interferon (IFN-γ) mRNA in both mLN and spleen. Levels of GATA-3/IL-4 mRNA or RORγt/IL-17 mRNA decreased in the infected mice, indicating Th1 cell polarization and the reduction of Th2 and Th17 cell polarization. The severity of arthritis was related to Th1 cell polarization accompanied by Th17 cell reduction, demonstrating the protective role of the T. gondii-derived Th1 response against Th17 cell-mediated arthritis in IL-1Ra-deficient mice.

Huntingtons Disease Mice Infected with Toxoplasma gondii Demonstrate Early Kynurenine Pathway Activation, Altered CD8+ T-Cell Responses, and Premature Mortality.

PubMed

Donley, David W; Olson, Andrew R; Raisbeck, Merl F; Fox, Jonathan H; Gigley, Jason P

2016-01-01

Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a polyglutamine-repeat expansion in the huntingtin protein. Activation of the kynurenine pathway of tryptophan degradation is implicated in the pathogenesis of HD. Indoleamine-2,3-dioxygenase (IDO) catalyzes the oxidation of tryptophan to kynurenine, the first step in this pathway. The prevalent, neuroinvasive protozoal pathogen Toxoplasma gondii (T. gondii) results in clinically silent life-long infection in immune-competent individuals. T. gondii infection results in activation of IDO which provides some protection against the parasite by depleting tryptophan which the parasite cannot synthesize. The kynurenine pathway may therefore represent a point of synergism between HD and T. gondii infection. We show here that IDO activity is elevated at least four-fold in frontal cortex and striata of non-infected N171-82Q HD mice at 14-weeks corresponding to early-advanced HD. T. gondii infection at 5 weeks resulted in elevation of cortical IDO activity in HD mice. HD-infected mice died significantly earlier than wild-type infected and HD control mice. Prior to death, infected HD mice demonstrated decreased CD8+ T-lymphocyte proliferation in brain and spleen compared to wild-type infected mice. We demonstrate for the first time that HD mice have an altered response to an infectious agent that is characterized by premature mortality, altered immune responses and early activation of IDO. Findings are relevant to understanding how T. gondii infection may interact with pathways mediating neurodegeneration in HD.

Huntingtons Disease Mice Infected with Toxoplasma gondii Demonstrate Early Kynurenine Pathway Activation, Altered CD8+ T-Cell Responses, and Premature Mortality

PubMed Central

Donley, David W.; Olson, Andrew R.; Raisbeck, Merl F.; Fox, Jonathan H.; Gigley, Jason P.

2016-01-01

Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a polyglutamine-repeat expansion in the huntingtin protein. Activation of the kynurenine pathway of tryptophan degradation is implicated in the pathogenesis of HD. Indoleamine-2,3-dioxygenase (IDO) catalyzes the oxidation of tryptophan to kynurenine, the first step in this pathway. The prevalent, neuroinvasive protozoal pathogen Toxoplasma gondii (T. gondii) results in clinically silent life-long infection in immune-competent individuals. T. gondii infection results in activation of IDO which provides some protection against the parasite by depleting tryptophan which the parasite cannot synthesize. The kynurenine pathway may therefore represent a point of synergism between HD and T. gondii infection. We show here that IDO activity is elevated at least four-fold in frontal cortex and striata of non-infected N171-82Q HD mice at 14-weeks corresponding to early–advanced HD. T. gondii infection at 5 weeks resulted in elevation of cortical IDO activity in HD mice. HD-infected mice died significantly earlier than wild-type infected and HD control mice. Prior to death, infected HD mice demonstrated decreased CD8+ T-lymphocyte proliferation in brain and spleen compared to wild-type infected mice. We demonstrate for the first time that HD mice have an altered response to an infectious agent that is characterized by premature mortality, altered immune responses and early activation of IDO. Findings are relevant to understanding how T. gondii infection may interact with pathways mediating neurodegeneration in HD. PMID:27611938

Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum

PubMed Central

Teixeira, Luzia; Moreira, João; Melo, Joana; Bezerra, Filipa; Marques, Raquel M; Ferreirinha, Pedro; Correia, Alexandra; Monteiro, Mariana P; Ferreira, Paula G; Vilanova, Manuel

2015-01-01

The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet+ cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-γ was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue. PMID:25581844

Immunohematopoietic modulation by oral β-1,3-glucan in mice infected with Listeria monocytogenes.

PubMed

Torello, Cristiane O; de Souza Queiroz, Julia; Oliveira, Sueli C; Queiroz, Mary L S

2010-12-01

In this study we demonstrated that the oral administration of β-1,3-glucan (Imunoglucan®) protects mice from a lethal dose of Listeria monocytogenes (LM) when administered prophylactically for 10 days at the doses of 150 and 300 mg/kg, with survival rates up to 40%. These doses also prevented the myelosuppression and the splenomegaly caused by a sublethal infection with LM, due to increased numbers of granulocyte-macrophage progenitors (CFU-GM) in the bone marrow. Investigation of the production of colony-stimulating factors revealed an increased colony-stimulating activity (CSA) in the serum of infected mice pre-treated with Imunoglucan®. The treatment also restored the reduced ability of stromal cells to display myeloid progenitors in long-term bone marrow cultures (LTBMC) and up-regulated IL-6 and IL-1α production by these cells in the infected mice, which was consistent with higher number of non-adherent cells. Additional studies to investigate the levels of interferon-gamma (INF-γ) in the supernatant of splenocyte cultures demonstrated a further increase in the level of this cytokine in infected-treated mice, compared to infected controls. In all cases, no differences were observed between the responses of the two optimal biologically effective doses. In contrast, no significant changes were produced by the treatment with the 50mg/kg dose. In addition, no changes were observed in normal mice treated with the three doses used. All together our results suggest that orally given Imunoglucan® indirectly modulates immune activity and probably disengages Listeria induced suppression of these responses by inducing a higher reserve of myeloid progenitors in the bone marrow in consequence of biologically active cytokine release (CSFs, IL-1α, IL-6, and INF-γ). Copyright © 2010 Elsevier B.V. All rights reserved.

Crimean-Congo Hemorrhagic Fever in Humanized Mice Reveals Glial Cells as Primary Targets of Neurological Infection.

PubMed

Spengler, Jessica R; Kelly Keating, M; McElroy, Anita K; Zivcec, Marko; Coleman-McCray, JoAnn D; Harmon, Jessica R; Bollweg, Brigid C; Goldsmith, Cynthia S; Bergeron, Éric; Keck, James G; Zaki, Sherif R; Nichol, Stuart T; Spiropoulou, Christina F

2017-12-12

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral hemorrhagic disease seen exclusively in humans. Central nervous system (CNS) infection and neurological involvement have also been reported in CCHF. In the current study, we inoculated NSG-SGM3 mice engrafted with human hematopoietic CD34+ stem cells with low-passage CCHF virus strains isolated from human patients. In humanized mice, lethal disease develops, characterized by histopathological change in the liver and brain. To date, targets of neurological infection and disease have not been investigated in CCHF. CNS disease in humanized mice was characterized by gliosis, meningitis, and meningoencephalitis, and glial cells were identified as principal targets of infection. Humanized mice represent a novel lethal model for studies of CCHF countermeasures, and CCHF-associated CNS disease. Our data suggest a role for astrocyte dysfunction in neurological disease and identify key regions of infection in the CNS for future investigations of CCHF. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Pathogenesis of Vesicular Stomatitis New Jersey Virus Infection in Deer Mice ( Peromyscus maniculatus) Transmitted by Black Flies ( Simulium vittatum).

PubMed

Mesquita, L P; Diaz, M H; Howerth, E W; Stallknecht, D E; Noblet, R; Gray, E W; Mead, D G

2017-01-01

The natural transmission of vesicular stomatitis New Jersey virus (VSNJV), an arthropod-borne virus, is not completely understood. Rodents may have a role as reservoir or amplifying hosts. In this study, juvenile and nestling deer mice ( Peromyscus maniculatus) were exposed to VSNJV-infected black fly ( Simulium vittatum) bites followed by a second exposure to naive black flies on the nestling mice. Severe neurological signs were observed in some juvenile mice by 6 to 8 days postinoculation (DPI); viremia was not detected in 25 juvenile deer mice following exposure to VSNJV-infected fly bites. Both juvenile and nestling mice had lesions and viral antigen in the central nervous system (CNS); in juveniles, their distribution suggested that the sensory pathway was the most likely route to the CNS. In contrast, a hematogenous route was probably involved in nestling mice, since all of these mice developed viremia and had widespread antigen distribution in the CNS and other tissues on 2 DPI. VSNJV was recovered from naive flies that fed on viremic nestling mice. This is the first report of viremia in a potential natural host following infection with VSNJV via insect bite and conversely of an insect becoming infected with VSNJV by feeding on a viremic host. These results, along with histopathology and immunohistochemistry, show that nestling mice have widespread dissemination of VSNJV following VSNJV-infected black fly bite and are a potential reservoir or amplifying host for VSNJV.

Increased infectivity of anchorless mouse scrapie prions in transgenic mice overexpressing human prion protein.

PubMed

Race, Brent; Phillips, Katie; Meade-White, Kimberly; Striebel, James; Chesebro, Bruce

2015-06-01

Prion protein (PrP) is found in all mammals, mostly as a glycoprotein anchored to the plasma membrane by a C-terminal glycosylphosphatidylinositol (GPI) linkage. Following prion infection, host protease-sensitive prion protein (PrPsen or PrPC) is converted into an abnormal, disease-associated, protease-resistant form (PrPres). Biochemical characteristics, such as the PrP amino acid sequence, and posttranslational modifications, such as glycosylation and GPI anchoring, can affect the transmissibility of prions as well as the biochemical properties of the PrPres generated. Previous in vivo studies on the effects of GPI anchoring on prion infectivity have not examined cross-species transmission. In this study, we tested the effect of lack of GPI anchoring on a species barrier model using mice expressing human PrP. In this model, anchorless 22L prions derived from tg44 mice were more infectious than 22L prions derived from C57BL/10 mice when tested in tg66 transgenic mice, which expressed wild-type anchored human PrP at 8- to 16-fold above normal. Thus, the lack of the GPI anchor on the PrPres from tg44 mice appeared to reduce the effect of the mouse-human PrP species barrier. In contrast, neither source of prions induced disease in tgRM transgenic mice, which expressed human PrP at 2- to 4-fold above normal. Prion protein (PrP) is found in all mammals, usually attached to cells by an anchor molecule called GPI. Following prion infection, PrP is converted into a disease-associated form (PrPres). While most prion diseases are species specific, this finding is not consistent, and species barriers differ in strength. The amino acid sequence of PrP varies among species, and this variability affects prion species barriers. However, other PrP modifications, including glycosylation and GPI anchoring, may also influence cross-species infectivity. We studied the effect of PrP GPI anchoring using a mouse-to-human species barrier model. Experiments showed that prions produced by

Immunological aspects of Giardia muris and Spironucleus muris infections in inbred and outbred strains of laboratory mice: a comparative study.

PubMed

Brett, S J; Cox, F E

1982-08-01

The intestinal flagellates, Giardia muris and Spironucleus muris, cause similar infections in CBA mice as determined by trophozoite and cyst counts. Both parasites occur all along the small intestine with G. muris, being mainly present in the anterior part and S. muris towards the posterior. The early stages of infection are similar in all strains of mice examined and peak levels of both trophozoites and cysts occur 1-2 weeks after infection. All strains of mice overcome the infection but the rate of recovery varies considerably between strains, being most rapid in BALB/c and slowest in A and C57BL.B10. Outbred mice are more variable in their recovery than inbred mice. After recovery, mice are partially resistant to reinfection with the homologous but not the heterologous parasite. Resistance to reinfection with S. muris is greatest in those strains that eliminate the primary infection most rapidly. Giardia muris and S. muris cause similar changes in the mucosa of the small intestine of BALB/c mice with increased intra-epithelial lymphocyte counts from 3 weeks onwards corresponding with the start of the elimination of the parasites from the gut. A reduction in villus height and increase in crypt depth is also characteristic of these infections.

Early life rhinovirus infection exacerbates house-dust-mite induced lung disease more severely in female mice.

PubMed

Phan, Jennifer A; Kicic, Anthony; Berry, Luke J; Sly, Peter D; Larcombe, Alexander N

2016-01-01

Recent studies have employed animal models to investigate links between rhinovirus infection and allergic airways disease, however, most do not involve early life infection, and none consider the effects of sex on responses. Here, we infected male and female mice with human rhinovirus 1B (or control) on day 7 of life. Mice were then subjected to 7 weeks of exposure to house-dust-mite prior to assessment of bronchoalveolar inflammation, serum antibodies, lung function, and responsiveness to methacholine. There were significant differences in responses between males and females in most outcomes. In males, chronic house-dust-mite exposure increased bronchoalveolar inflammation, house-dust-mite specific IgG1 and responsiveness of the lung parenchyma, however, there was no additional impact of rhinovirus infection. Conversely, in females, there were additive and synergistic effects of rhinovirus infection and house-dust-mite exposure on neutrophilia, airway resistance, and responsiveness of the lung parenchyma. We conclude that early life rhinovirus infection influences the development of house-dust-mite induced lung disease in female, but not male mice.

Vitamin E reduces hepatic fibrosis in mice with Schistosoma japonicum infection.

PubMed

Wang, Xuefeng; Zhang, Rongbo; Du, Jiuwei; Hu, Youying; Xu, Lifa; Lu, Jun; Ye, Song

2012-02-01

To investigate whether vitamin E protects against hepatic fibrosis in mice with Schistosoma japonicum infection, 24 pathogen-free Kunming mice were selected and randomly divided into four groups: control (uninfected, untreated), model (infected, untreated), low-dose intervention (infected, vitamin E-treated, 30 mg/g bodyweight/day) and high-dose intervention (infected, vitamin E-treated, 60 mg/g bodyweight/day). Mice were infected with Schistosoma japonicum by inoculating abdominal skin with snail hosts. The activities of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were detected in hepatic tissue by colorimetry. The expression levels of laminin (LN), hyaluronic acid (HA), procollagen type Ⅲ (PC-III) and type Ⅳ collagen (IV-C) were detected in the serum by radioimmunoassay. Finally, areas and numbers of granulomas were assessed through histopathology 42 days following treatment. The results revealed that mean areas of granulomas were smaller in the low- and high-dose intervention groups compared to those in the model group. Furthermore, the higher dose of vitamin E resulted in smaller granulomas than the low dose. The levels of LN, HA, PC-III and IV-C in the serum were lower following vitamin E treatment than in the model group. By contrast, activity of SOD, GPx and CAT in hepatic tissue was higher following vitamin E treatment compared to the model group. The activity of MDA was lower in hepatic tissue following vitamin E treatment compared to the model group, but was higher compared to controls. In general, the higher dose of vitamin E affected measurements to a greater extent than the lower dose. In conclusion, vitamin E treatment may reduce the growth of granulomas, slowing the process of hepatic fibrosis, and this effect may be the result of the altered activity of the oxidation-reduction enzyme system.

The effect of centaurein on interferon-{gamma} expression and Listeria infection in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, S.-L.; Department of Biological Science and Technology, National Chiao Tung University, 1001, Ta Hsueh Road, Hsinchu 300, Taiwan; Yeh, H.-H.

2007-02-15

We previously found that centaurein enhanced IFN-{gamma} transcription in T cells. Here, we demonstrate that centaurein increased the IFN-{gamma} expression in T and NK cells and the serum IFN-{gamma} level in mice. Centaurein elevated the transcription of T-bet but not GATA-3, which is consistent with its effect on that of IFN-{gamma} but not IL-4. Additionally, centaurein effectively protected mice against Listeria infection. Moreover, centaurein per se or in combination with antibiotics could treat Listeria infection. Our mechanistic studies suggest that centaurein augments IFN-{gamma} expression via a transcriptional up-regulation of T-bet and that centaurein protects against or treats Listeria infection viamore » a modulation of IFN-{gamma} expression.« less

Helicobacter pylori-infected C57BL/6 mice with different gastrointestinal microbiota have contrasting gastric pathology, microbial and host immune responses.

PubMed

Ge, Zhongming; Sheh, Alexander; Feng, Yan; Muthupalani, Sureshkumar; Ge, Lili; Wang, Chuanwu; Kurnick, Susanna; Mannion, Anthony; Whary, Mark T; Fox, James G

2018-05-22

C57BL/6 (B6) mice from Taconic Sciences (Tac) and the Jackson Laboratory (Jax) were infected with H. pylori PMSS1 (Hp) for 16 week; there was no significant difference in the gastric histologic activity index between Hp infected Tac and Jax B6. However, the degree of gastric mucous metaplasia and Th1-associated IgG2c levels in response to Hp infection were increased in Tac mice over Jax mice, whereas the colonization levels of gastric Hp were higher by 8-fold in Jax B6 compared with Tac B6. Additionally, mRNA expression of gastric Il-1β, Il-17A and RegIIIγ were significantly lower in the infected Tac compared to the infected Jax mice. There were significant differences in the microbial community structures in stomach, colon, and feces between Jax and Tac B6 females. Differences in gastric microbial communities between Jax and Tac B6 females are predicted to affect the metagenome. Moreover, Hp infection perturbed the microbial community structures in the stomach, colon and feces of Jax mice, but only altered the colonic microbial composition of Tac mice. Our data indicate that the GI microbiome of Tac B6 mice is compositionally distinct from Jax B6 mice, which likely resulted in different pathological, immunological, and microbial responses to Hp infection.

HTLV-1 Infection and Neuropathogenesis in the Context of Rag1-/-γc-/- (RAG1-Hu) and BLT Mice.

PubMed

Ginwala, Rashida; Caruso, Breanna; Khan, Zafar K; Pattekar, Ajinkya; Chew, Glen M; Corley, Michael J; Loonawat, Ronak; Jacobson, Steven; Sreedhar, Sreesha; Ndhlovu, Lishomwa C; Jain, Pooja

2017-09-01

To date, the lack of a suitable small animal model has hindered our understanding of Human T-cell lymphotropic virus (HTLV)-1 chronic infection and associated neuropathogenesis defined as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The host immune response plays a critical role in the outcome of HTLV-1 infection, which could be better tested in the context of humanized (hu) mice. Thus, we employ here the Balb/c-Rag1 -/- γc -/- or Rag1 as well as Bone marrow-Liver-Thymic (BLT) mouse models for engraftment of human CD34 + hematopoietic stem cells. Flow cytometry and histological analyses confirmed reconstitution of Rag1 and BLT mice with human immune cells. Following HTLV-1 infection, proviral load (PVL) was detected in the blood of Rag-1 and BLT hu-mice as early as 2 weeks post-infection (wpi) with sustained elevation in the subsequent weeks followed by Tax expression. Additionally, infection was compared between adult and neonatal Rag1 mice with both PVL and Tax expression considerably higher in the adult Rag1 mice as compared to the neonates. Establishment of peripheral infection led to lymphocytic infiltration with concomitant Tax expression and resulting myelin disruption within the central nervous system of infected mice. In addition, up-regulation in the expression of several immune checkpoint mediators such as programmed cell death-1 (PD-1), T-cell Ig and ITIM domain (TIGIT), and T cell Ig and mucin domain-3 protein (Tim-3) were observed on CD8 + T cells in various organs including the CNS of infected hu-mice. Collectively, these studies represent the first attempt to establish HTLV-1 neuropathogenesis in the context of Rag-1 and BLT hu-mice as potential novel tools for understanding HTLV-1 neuropathogenesis and testing of novel therapies such as immune checkpoint blockade in the amelioration of chronic HTLV-1 infection.

Inactivated and live, attenuated influenza vaccines protect mice against influenza:Streptococcus pyogenes super-infections

PubMed Central

Chaussee, Michael S.; Sandbulte, Heather R.; Schuneman, Margaret J.; DePaula, Frank P.; Addengast, Leslie A.; Schlenker, Evelyn H.; Huber, Victor C.

2011-01-01

Mortality associated with influenza virus super-infections is frequently due to secondary bacterial complications. To date, super-infections with Streptococcus pyogenes have been studied less extensively than those associated with S. pneumoniae. This is significant because a vaccine for S. pyogenes is not clinically available, leaving vaccination against influenza virus as our only means for preventing these super-infections. In this study, we directly compared immunity induced by two types of influenza vaccine, either inactivated influenza virus (IIV) or live, attenuated influenza virus (LAIV), for the ability to prevent super-infections. Our data demonstrate that both IIV and LAIV vaccines induce similar levels of serum antibodies, and that LAIV alone induces IgA expression at mucosal surfaces. Upon super-infection, both vaccines have the ability to limit the induction of pro-inflammatory cytokines within the lung, including IFN-γ which has been shown to contribute to mortality in previous models of super-infection. Limiting expression of these pro-inflammatory cytokines within the lungs subsequently limits recruitment of macrophages and neutrophils to pulmonary surfaces, and ultimately protects both IIV- and LAIV-vaccinated mice from mortality. Despite their overall survival, both IIV- and LAIV-vaccinated mice demonstrated levels of bacteria within the lung tissue to levels that are similar to those seen in unvaccinated mice. Thus, influenza virus:bacteria super-infections can be limited by vaccine-induced immunity against influenza virus, but the ability to prevent morbidity is not complete. PMID:21440037

Respiratory Syncytial Virus (RSV) Pulmonary Infection in Humanized Mice Induces Human Anti-RSV Immune Responses and Pathology

PubMed Central

Sharma, Anurag; Wu, Wenzhu; Sung, Biin; Huang, Jing; Tsao, Tiffany; Li, Xiangming; Gomi, Rika; Tsuji, Moriya

2016-01-01

ABSTRACT Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract disease, which causes high rates of morbidity and mortality in infants and the elderly. Models of human RSV pulmonary disease are needed to better understand RSV pathogenesis and to assess the efficacy of RSV vaccines. We assessed the RSV-specific human innate, humoral, and cellular immune responses in humanized mice (mice with a human immune system [HIS mice]) with functional human CD4+ T and B cells. These mice were generated by introduction of HLA class II genes, various human cytokines, and human B cell activation factor into immunodeficient NOD scid gamma (NSG) mice by the use of an adeno-associated virus vector, followed by engraftment of human hematopoietic stem cells. During the first 3 days of infection, HIS mice lost more weight and cleared RSV faster than NSG mice. Human chemokine (C-C motif) ligand 3 (CCL3) and human interleukin-1β (IL-1β) expression was detected in the RSV-infected HIS mice. The pathological features induced by RSV infection in HIS mice included peribronchiolar inflammation, neutrophil predominance in the bronchioalveolar lavage fluid, and enhanced airway mucus production. Human anti-RSV IgG and RSV-neutralizing antibodies were detected in serum and human anti-RSV mucosal IgA was detected in bronchioalveolar lavage fluid for up to 6 weeks. RSV infection induced an RSV-specific human gamma interferon response in HIS mouse splenocytes. These results indicate that human immune cells can induce features of RSV lung disease, including mucus hyperplasia, in murine lungs and that HIS mice can be used to elicit human anti-RSV humoral and cellular immunity. IMPORTANCE Infections with respiratory syncytial virus (RSV) are common and can cause severe lung disease in infants and the elderly. The lack of a suitable animal model with disease features similar to those in humans has hampered efforts to predict the efficacy of novel anti-RSV therapies and

Pneumonia Virus of Mice Severe Respiratory Virus Infection in a Natural Host

PubMed Central

Rosenberg, Helene F.; Domachowske, Joseph B.

2008-01-01

Pneumonia virus of mice (PVM; family Paramyxoviridae, genus Pneumovirus) is a natural mouse pathogen that is closely related to the human and bovine respiratory syncytial viruses. Among the prominent features of this infection, robust replication of PVM takes place in bronchial epithelial cells in response to a minimal virus inoculum. Virus replication in situ results in local production of proinflammatory cytokines (MIP-1α, MIP-2, MCP-1 and IFNγ) and granulocyte recruitment to the lung. If left unchecked, PVM infection and the ensuing inflammatory response ultimately lead to pulmonary edema, respiratory compromise and death. In this review, we consider the recent studies using the PVM model that have provided important insights into the role of the inflammatory response in the pathogenesis of severe respiratory virus infection. We also highlight several works that have elucidated acquired immune responses to this pathogen, including T cell responses and the development of humoral immunity. Finally, we consider several immunomodulatory strategies that have been used successfully to reduce morbidity and mortality when administered to PVM infected, symptomatic mice, and thus hold promise as realistic therapeutic strategies for severe respiratory virus infections in human subjects. PMID:18471897

Dietary L-glutamine supplementation improves pregnancy outcome in mice infected with type-2 porcine circovirus.

PubMed

Ren, Wenkai; Luo, Wei; Wu, Miaomiao; Liu, Gang; Yu, Xinglong; Fang, Jun; Li, Teijun; Yin, Yulong; Wu, Guoyao

2013-09-01

Porcine circovirus type 2 (PCV2) causes reproductive failure in swine. As glutamine can enhance immune function in animals, this study was conducted with mice to test the hypothesis that dietary glutamine supplementation will improve pregnancy outcome in PCV2-infected dams. Beginning on day 0 of gestation, mice were fed a standard diet supplemented with 1.0% L-glutamine or 1.22% L-alanine (isonitrogenous control). All mice were infected with PCV2 (2000 TCID50) on day 10 of gestation. On day 17 of gestation, six mice from each group were euthanized to obtain maternal tissues and fetuses for hematology and histopathology tests. The remaining mice continued to receive their respective diets supplemented with 1.0% L-glutamine or 1.22% L-alanine through lactation. The PCV2 virus was present in maternal samples (serum and lung) of most mice in the control group but was not detected in the glutamine-supplemented mice. Dietary glutamine supplementation reduced abortion, decreased fetal deaths, and enhanced neonatal survival. The glutamine treatment also reduced concentrations of interleukin-6, while increasing concentrations of tumor necrosis factor-α and C-reactive protein, in the maternal serum of mice. Furthermore, glutamine supplementation attenuated microscopic lesions in maternal tissues (lung, spleen, and liver). Collectively, these results indicate that dietary glutamine supplementation is beneficial for ameliorating reproductive failure in virus-infected mice. The findings support the notion that gestating dams require adequate amounts of dietary glutamine for the optimal survival and growth of embryos, fetuses, and neonates, and have important implications for nutritional support of mammals (including swine and humans) during gestation and lactation.

Evaluation of disinfectants and antiseptics to eliminate bacteria from the surface of turkey eggs and hatch gnotobiotic poults.

PubMed

Sylte, M J; Chandra, L C; Looft, T

2017-07-01

Bird eggs are in contact with intestinal microbiota at or after oviposition, but are protected from bacterial translocation by a glycoprotein cuticle layer, the shell, and internal membranes. In a preliminary study, turkey eggs were hatched in a germ-free environment. Firmicutes 16S rRNA gene was detected in the cecal microbiota of hatched poults, suggesting that poults may acquire spore-formers by exposure to shell contents during hatching. Generating gnotobiotic poults for research requires elimination of bacteria from the egg's surface without damaging the developing embryo. The ability of different disinfectants and antiseptics to eliminate eggshell bacteria without harming the developing embryo was tested. Different classes of disinfectants and antiseptics (halogens, biguanidines, and oxidants) were selected to target spores and vegetative bacteria likely present on the egg's surface. Eggs were treated by fully immersing in heated antiseptic (betadine or chlorhexidine) or disinfectant (alkaline bleach, acidified bleach, chlorine dioxide, Oxysept-333, or Virkon S) solutions for up to 15 minutes. Shells were aseptically harvested for aerobic and anaerobic culturing of bacteria. Toxicity to the developing embryo was assessed by gross evaluation of developmental changes in treated eggs incubated up to 27 d of embryonation. Halogen disinfectants acidified bleach and chlorine dioxide, and oxidants Oxysept-333 and Virkon-S eliminated viable bacteria from eggshells. However, addition of oxidants, alone or in combination with other treatments, produced significant (P < 0.05) embryotoxicity. The combination treatment of acidified bleach, chlorine dioxide, and betadine produced minimal embryotoxicity and eliminated viable bacteria from whole turkey eggs, and produced hatched poults in a gnotobiotic isolator. As a control, eggs were treated with PBS, incubated, and hatched under germ-replete conditions. After hatching, poults were euthanized and treated poults had no

Effect of cold water-induced stress on immune response, pathology and fertility in mice during Chlamydia muridarum genital infection

PubMed Central

Belay, Tesfaye; Woart, Anthony; Graffeo, Vincent

2017-01-01

Abstract Genital infection by Chlamydia trachomatis is the most common bacterial sexually transmitted disease worldwide. It causes serious reproductive health complications, including pelvic inflammatory disease and infertility. Stress is implicated as a risk factor for various infections; however, its effect on chlamydia genital infection is unknown. We previously showed that repeated exposure of mice to cold water results in increased severity of chlamydia genital infection. In this study, cold water-induced stress resulted in (i) elevated levels of norepinephrine (NE) and epinephrine in the spleen and genital tract of stressed mice; (ii) elevated IL-1β, TNF-α, IL-6 and nitric oxide production in macrophage-rich peritoneal cells of mice; (iii) supplement of NE in vitro exerts an immunosuppressive effect on splenic T-cell production of cytokines; (iv) decreased C. muridarum shedding in the genital tract of β1Adr/β2Adr receptor KO mice; and (v) a higher rate of infertility in infected mice. These results suggest that cold water stress induces the production of catecholamines, which may play a critical role in the modulation of the immune system leading to increased intensity of C. muridarum genital infection. PMID:28431099

Comparative study of murid gammaherpesvirus 4 infection in mice and in a natural host, bank voles.

PubMed

François, Sylvie; Vidick, Sarah; Sarlet, Michaël; Michaux, Johan; Koteja, Pawel; Desmecht, Daniel; Stevenson, Philip G; Vanderplasschen, Alain; Gillet, Laurent

2010-10-01

Gammaherpesviruses are archetypal pathogenic persistent viruses. The known human gammaherpesviruses (Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus) are host-specific and therefore lack a convenient in vivo infection model. This makes related animal gammaherpesviruses an important source of information. Infection by murid herpesvirus 4 (MuHV-4), a virus originally isolated from bank voles (Myodes glareolus), was studied here. MuHV-4 infection of inbred laboratory mouse strains (Mus musculus) is commonly used as a general model of gammaherpesvirus pathogenesis. However, MuHV-4 has not been isolated from house mice, and no systematic comparison has been made between experimental MuHV-4 infections of mice and bank voles. This study therefore characterized MuHV-4 (strain MHV-68) infection of bank voles through global luciferase imaging and classical virological methods. As in mice, intranasal virus inoculation led to productive replication in bank vole lungs, accompanied by massive cellular infiltrates. However, the extent of lytic virus replication was approximately 1000-fold lower in bank voles than in mice. Peak latency titres in lymphoid tissue were also lower, although latency was still established. Finally, virus transmission was tested between animals maintained in captivity. However, as observed in mice, MuHV-4 was not transmitted between voles under these conditions. In conclusion, this study revealed that, despite quantitative differences, replication and the latency sites of MuHV-4 are comparable in bank voles and mice. Therefore, it appears that, so far, Mus musculus represents a suitable host for studying gammaherpesvirus pathogenesis with MuHV-4. Establishing transmission conditions in captivity will be a vital step for further research in this field.

Role of Capsule and Suilysin in Mucosal Infection of Complement-Deficient Mice with Streptococcus suis

PubMed Central

Seitz, Maren; Beineke, Andreas; Singpiel, Alena; Willenborg, Jörg; Dutow, Pavel; Goethe, Ralph; Valentin-Weigand, Peter; Klos, Andreas

2014-01-01

Virulent Streptococcus suis serotype 2 strains are invasive extracellular bacteria causing septicemia and meningitis in piglets and humans. One objective of this study was to elucidate the function of complement in innate immune defense against S. suis. Experimental infection of wild-type (WT) and C3−/− mice demonstrated for the first time that the complement system protects naive mice against invasive mucosal S. suis infection. S. suis WT but not an unencapsulated mutant caused mortality associated with meningitis and other pathologies in C3−/− mice. The capsule contributed also substantially to colonization of the upper respiratory tract. Experimental infection of C3−/− mice with a suilysin mutant indicated that suilysin expression facilitated an early disease onset and the pathogenesis of meningitis. Flow cytometric analysis revealed C3 antigen deposition on the surface of ca. 40% of S. suis WT bacteria after opsonization with naive WT mouse serum, although to a significantly lower intensity than on the unencapsulated mutant. Ex vivo multiplication in murine WT and C3−/− blood depended on capsule but not suilysin expression. Interestingly, S. suis invasion of inner organs was also detectable in C5aR−/− mice, suggesting that chemotaxis and activation of immune cells via the anaphylatoxin receptor C5aR is, in addition to opsonization, a further important function of the complement system in defense against mucosal S. suis infection. In conclusion, we unequivocally demonstrate here the importance of complement against mucosal S. suis serotype 2 infection and that the capsule of this pathogen is also involved in escape from complement-independent immunity. PMID:24686060

Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

PubMed

Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

2015-06-01

In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population.

Role of neutralizing antibodies and T-cells in pathogenesis of herpes simplex virus infection in congenitally athymic mice.

PubMed

Kapoor, A K; Buckmaster, A; Nash, A A; Field, H J; Wildy, P

1982-11-01

Congenitally athymic nude mice were infected with 10(4) p.f.u. herpes simplex type 1 (strain SC16). Following the passive transfer of neutralizing monoclonal antibodies (AP7, AP8 and AP12) it was observed that AP7 alone reduced the virus infectivity in the nervous system; AP8 and AP12 failed to protect mice probably due to poor in vivo binding to the neutralization site on the virus. Latent ganglionic infection could be established in nude mice following adoptive transfer of optimum number (2 x 10(7) cells/mouse) of immune lymph node cells from day 7 herpes virus-infected hairy immunocompetent donor mice. Moreover, in some of the immune lymph node cell protected nudes, latency could be maintained even in complete absence of neutralizing antibodies. Results of ear-ablation experiments revealed that removal of primary source of infection after day 5 of infection reduced the amount of virus in the ganglia and spinal cord. Acute neurological infection was not detected following transfer of protective anti-gp-D neutralizing antibody (LP2) in combination with removal of infected pinna. These data suggest that continuous seeding of virus occurs in related ganglia via the axonal route from infected ear pinna. It appears that local T-cell-mediated immune mechanisms are involved in maintenance of latency.

Exogenous cytokine modulation or neutralization of interleukin-10 enhance survival in lipopolysaccharide-hyporesponsive C3H/HeJ mice with Klebsiella infection

PubMed Central

Wang, M-J; Jeng, K-C G; Ping, L-I

1999-01-01

Klebsiella pneumoniae has been isolated from liver abscesses in patients with leukaemia or diabetes. The resistance of Klebsiella infection in lipopolysaccharide (LPS)-hyporesponsive mice is unclear. Female C3H/HeJ and C3H/HeN mice, 6–8 weeks old, were intraperitoneally (i.p.) injected with K. pneumoniae. The results showed that C3H/HeJ mice were 24 times more susceptible [lethal dose 50% (LD50) 250 colony-forming units] than C3H/HeN mice to K. pneumoniae infection. C3H/HeJ mice, uninfected or infected with K. pneumoniae, had higher liver interleukin (IL)-10 levels and IL-10 mRNA levels than C3H/HeN mice. Previously, pretreatment with IL-1β and tumour necrosis factor-α (TNF-α) protected C3H/HeJ mice from lethal bacterial infection. Therefore the effects of pretreatment with IL-1β and TNF-α or antimurine IL-10 antibody i.p. 1 hr before this infection in both strains of C3H mice were examined. Pretreatment with TNF-α or anti-IL-10 antibody enhanced the survival of both strains of mice. TNF-α, in combination with IL-1β, enhanced the survival and bacterial clearance better than single pretreatment in C3H/HeJ mice. Anti-IL-10 antibody increased bacterial clearance and significantly reduced liver cytokine mRNA levels in C3H/HeJ mice more than it did in the controls during infection. These results indicate that exogenous cytokine modulation or neutralization of IL-10 enhance the resistance of LD50 infection in C3H/HeJ mice. PMID:10469238

[Intestinal disorder of anaerobic bacteria aggravates pulmonary immune pathological injury of mice infected with influenza virus].

PubMed

Wu, Sha; Yan, Yuqi; Zhang, Mengyuan; Shi, Shanshan; Jiang, Zhenyou

2016-04-01

To investigate the relationship between the intestinal disorder of anaerobic bacteria and influenza virus infection, and the effect on pulmonary inflammatory cytokines in mice. Totally 36 mice were randomly divided into normal control group, virus-infected group and metronidazole treatment group (12 mice in each group). Mice in the metronidazole group were administrated orally with metronidazole sulfate for 8 days causing anaerobic bacteria flora imbalance; then all groups except the normal control group were treated transnasally with influenza virus (50 μL/d FM1) for 4 days to establish the influenza virus-infected models. Their mental state and lung index were observed, and the pathological morphological changes of lung tissues, caecum and intestinal mucosa were examined by HE staining. The levels of interleukin 4 (IL-4), interferon γ (IFN-γ), IL-10 and IL-17 in the lung homogenates were determined by ELISA. Compared with the virus control group, the metronidazole group showed obviously increased lung index and more serious pathological changes of the lung tissue and appendix inflammation performance. After infected by the FM1 influenza virus, IFN-γ and IL-17 of the metronidazole group decreased significantly and IL-4 and IL-10 levels were raised, but there was no statistically difference between the metronidazole and virus control groups. Intestinal anaerobic bacteria may inhibit the adaptive immune response in the lungs of mice infected with FM1 influenza virus through adjusting the lung inflammatory factors, affect the replication and clean-up time of the FM1 influenza virus, thus further aggravating pulmonary immune pathological injury caused by the influenza virus infection.

Species-Specific Immunity Induced by Infection with Entamoeba histolytica and Entamoeba moshkovskii in Mice

PubMed Central

Shimokawa, Chikako; Culleton, Richard; Imai, Takashi; Suzue, Kazutomo; Hirai, Makoto; Taniguchi, Tomoyo; Kobayashi, Seiki; Hisaeda, Hajime; Hamano, Shinjiro

2013-01-01

Entamoeba histolytica, the parasitic amoeba responsible for amoebiasis, causes approximately 100,000 deaths every year. There is currently no vaccine against this parasite. We have previously shown that intracecal inoculation of E. histolytica trophozoites leads to chronic and non-healing cecitis in mice. Entamoeba moshkovskii, a closely related amoeba, also causes diarrhea and other intestinal disorders in this model. Here, we investigated the effect of infection followed by drug-cure of these species on the induction of immunity against homologous or heterologous species challenge. Mice were infected with E. histolytica or E. moshkovskii and treated with metronidazole 14 days later. Re-challenge with E. histolytica or E. moshkovskii was conducted seven or 28 days following confirmation of the clearance of amoebae, and the degree of protection compared to non-exposed control mice was evaluated. We show that primary infection with these amoebae induces a species-specific immune response which protects against challenge with the homologous, but not a heterologous species. These findings pave the way, therefore, for the identification of novel amoebae antigens that may become the targets of vaccines and provide a useful platform to investigate host protective immunity to Entamoeba infections. PMID:24312397

Chronic proliferative hepatitis in A/JCr mice associated with persistent Helicobacter hepaticus infection: a model of helicobacter-induced carcinogenesis.

PubMed Central

Fox, J G; Li, X; Yan, L; Cahill, R J; Hurley, R; Lewis, R; Murphy, J C

1996-01-01

Helicobacter hepaticus causes hepatitis in selected strains of mice and in A/JCr mice is linked to liver cancer. To analyze whether H. hepaticus persists in specified ecological niches, to determine whether biomarkers of infection exist, and to analyze the influence of H. hepaticus on hepatocyte proliferation, a longitudinal study of H. hepaticus-infected A/JCr mice was undertaken. A/JCr mice were serially euthanatized from 3 through 18 months and surveyed by enzyme-linked immunosorbent assay; bacterial culture of liver, colon, and cecum; histology; electron microscopy; hepatocyte proliferation indices determined by using 5-bromo-2'-deoxyuridine; and measurement of the liver enzyme alanine aminotransferase. In infected animals throughout the 18-month study, H. hepaticus was consistently isolated from the lower bowel but only sporadically from the liver. By electron microscopy, H. hepaticus was noted infrequently and only in bile canaliculi. Infected mice, particularly males, showed chronic inflammation; oval cell, Kupffer cell, and Ito cell hyperplasia; hepatocytomegaly; and bile duct proliferation. The inflammatory and necrotizing lesion was progressive and involved the hepatic parenchyma, portal triads, and intralobular venules. Hepatic adenomas were noted only in male mice, whereas 5-bromo-2'-deoxyuridine proliferation indices were markedly increased in both sexes, but especially in males, compared to control A/J mice. Infected mice also developed sustained anti-H. hepaticus serum immunoglobulin G antibody responses and elevated alanine aminotransferase levels. H. hepaticus, which persists in the lower bowels and livers of A/JCr mice, is associated with a chronic proliferative hepatitis, and hepatomas in selected male mice indicate that this novel bacterium may cause an increased risk of hepatic cancer induction in susceptible strains of mice. This murine model should prove useful in dissecting the molecular events operable in the development of neoplasms

Zika Virus Infection in Mice Causes Panuveitis with Shedding of Virus in Tears.

PubMed

Miner, Jonathan J; Sene, Abdoulaye; Richner, Justin M; Smith, Amber M; Santeford, Andrea; Ban, Norimitsu; Weger-Lucarelli, James; Manzella, Francesca; Rückert, Claudia; Govero, Jennifer; Noguchi, Kevin K; Ebel, Gregory D; Diamond, Michael S; Apte, Rajendra S

2016-09-20

Zika virus (ZIKV) is an emerging flavivirus that causes congenital abnormalities and Guillain-Barré syndrome. ZIKV infection also results in severe eye disease characterized by optic neuritis, chorioretinal atrophy, and blindness in newborns and conjunctivitis and uveitis in adults. We evaluated ZIKV infection of the eye by using recently developed mouse models of pathogenesis. ZIKV-inoculated mice developed conjunctivitis, panuveitis, and infection of the cornea, iris, optic nerve, and ganglion and bipolar cells in the retina. This phenotype was independent of the entry receptors Axl or Mertk, given that Axl(-/-), Mertk(-/-), and Axl(-/-)Mertk(-/-) double knockout mice sustained levels of infection similar to those of control animals. We also detected abundant viral RNA in tears, suggesting that virus might be secreted from lacrimal glands or shed from the cornea. This model provides a foundation for studying ZIKV-induced ocular disease, defining mechanisms of viral persistence, and developing therapeutic approaches for viral infections of the eye. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

[Early kinetics of Toxoplasma gondii infection in mice infected intragastrically with tachyzoites by chromogenic in situ hybridization targeting SAG2 mRNA].

PubMed

Meng, Xiao-li; Ma, Xiao-ming; Yin, Guo-rong; Liu, Hong-li; Yin, Li-tian; Shen, Jin-yan; Wang, Hai-long

2010-04-01

To observe the early kinetics of Toxoplasma gondii infection in mice inoculated with tachyzoites of RH strain. Twenty BALB/c mice were administered intragastrically with tachyzoites of RH strain (2 x 10(4)/mice). Parasite burdens in mesenteric lymph node (MLN), liver, spleen, lung and brain were determined by chromogenic in situ hybridization targeting SAG2 mRNA at 1, 2, 4, 6 and 8 days postinfection. Five mice were inoculated with PBS as blank control. The MLN, liver and spleen were the first organs where tachyzoites were found on the first day after infection, followed by the lungs on the 4th day and the brain on the 6th day. On days 6 to 8 after infection, there was a significant difference on parasite load among the tissues (P < 0.05), and the parasite load in MLN was highest, followed by that of liver, spleen, lungs and brain. The number of tachyzoites in various tissues was time-dependent. T. gondii tachyzoites were first detected in MLN, liver and spleen, then in the lungs, and finally in the brain. The number of tachyzoites in the MLNs increased more rapidly.

Zika Virus Infection during Pregnancy in Mice Causes Placental Damage and Fetal Demise.

PubMed

Miner, Jonathan J; Cao, Bin; Govero, Jennifer; Smith, Amber M; Fernandez, Estefania; Cabrera, Omar H; Garber, Charise; Noll, Michelle; Klein, Robyn S; Noguchi, Kevin K; Mysorekar, Indira U; Diamond, Michael S

2016-05-19

Zika virus (ZIKV) infection in pregnant women causes intrauterine growth restriction, spontaneous abortion, and microcephaly. Here, we describe two mouse models of placental and fetal disease associated with in utero transmission of ZIKV. Female mice lacking type I interferon signaling (Ifnar1(-/-)) crossed to wild-type (WT) males produced heterozygous fetuses resembling the immune status of human fetuses. Maternal inoculation at embryonic day 6.5 (E6.5) or E7.5 resulted in fetal demise that was associated with ZIKV infection of the placenta and fetal brain. We identified ZIKV within trophoblasts of the maternal and fetal placenta, consistent with a trans-placental infection route. Antibody blockade of Ifnar1 signaling in WT pregnant mice enhanced ZIKV trans-placental infection although it did not result in fetal death. These models will facilitate the study of ZIKV pathogenesis, in utero transmission, and testing of therapies and vaccines to prevent congenital malformations. Copyright © 2016 Elsevier Inc. All rights reserved.

Zika virus infection during pregnancy in mice causes placental damage and fetal demise

PubMed Central

Miner, Jonathan J.; Cao, Bin; Govero, Jennifer; Smith, Amber M.; Fernandez, Estefania; Cabrera, Omar H.; Garber, Charise; Noll, Michelle; Klein, Robyn S.; Noguchi, Kevin K.; Mysorekar, Indira U.; Diamond, Michael S.

2016-01-01

SUMMARY Zika virus (ZIKV) infection in pregnant women causes intrauterine growth restriction, spontaneous abortion, and microcephaly. Here, we describe two mouse models of placental and fetal disease associated with in utero transmission of ZIKV. Female mice lacking type I interferon signaling (Ifnar1−/−) crossed to wild-type (WT) males produced heterozygous fetuses resembling the immune status of human fetuses. Maternal inoculation at embryonic day 6.5 (E6.5) or E7.5 resulted in fetal demise that was associated with ZIKV infection of the placenta and fetal brain. We identified ZIKV within trophoblasts of the maternal and fetal placenta, consistent with a trans-placental infection route. Antibody blockade of Ifnar1 signaling in WT pregnant mice enhanced ZIKV trans-placental infection although it did not result in fetal death. These models will facilitate the study of ZIKV pathogenesis, in utero transmission, and testing of therapies and vaccines to prevent congenital malformations. PMID:27180225

Clinical chemistry of congenic mice with quantitative trait loci for predicted responses to Trypanosoma congolense infection.

PubMed

Rathkolb, Birgit; Noyes, Harry A; Brass, Andy; Dark, Paul; Fuchs, Helmut; Gailus-Durner, Valérie; Gibson, John; de Angelis, Martin Hrabé; Ogugo, Moses; Iraqi, Fuad; Kemp, Steve J; Naessens, Jan; Pope, Mathew E; Wolf, Eckhard; Agaba, Morris

2009-09-01

Trypanosoma congolense is a protozoan parasite that causes severe diseases in livestock. Three major quantative trait loci (QTL), Tir1, Tir2, and Tir3, control the survival time of mice after infection with T. congolense. Congenic mice carrying the C57BL/6 resistance alleles on the A/J background were developed for each of these loci. The congenic mice were used to physically map the regions containing the QTL gene(s) and to investigate the physiological effect of each locus. Clinical chemistry data for infected A/J, C57BL/6, and BALB/c mice were obtained for 15 analytes at five time points. Congenic mice were assessed for survival, parasitemia, and anemia as well as seven clinical-chemical analytes. The survival times were significantly increased in the Tir1 and Tir2 mice but not Tir3 congenic mice. The survival time of the parental inbred mice correlated negatively with parasitemia but positively with alanine aminotransferase activities in serum, suggesting that inflammatory reactions in the liver had a beneficial effect possibly associated with reduced parasitemia. However, there was no difference in parasitemia or liver enzyme activities of Tir1 and Tir2 congenic mice relative to their controls, showing that survival, parasitemia, and degree of liver damage are not associated with each other, despite the correlation in the parental lines. These data suggest that the congenic loci affect survival but do not affect control of parasite number. They may therefore act by limiting the pathological consequences of T. congolense infection.

Urinary tract infection in iNOS-deficient mice with focus on bacterial sensitivity to nitric oxide.

PubMed

Poljakovic, Mirjana; Persson, Katarina

2003-01-01

Inducible nitric oxide synthase (iNOS)-deficient mice were used to examine the role of iNOS in Escherichia coli-induced urinary tract infection (UTI). The toxicity of nitric oxide (NO)/peroxynitrite to bacteria and host was also investigated. The nitrite levels in urine of iNOS+/+ but not iNOS/ mice increased after infection. No differences in bacterial clearance or persistence were noted between the genotypes. In vitro, the uropathogenic E. coli 1177 was sensitive to 3-morpholinosydnonimine, whereas the avirulent E. coli HB101 was sensitive to both NO and 3-morpholinosydnonimine. E. coli HB101 was statistically (P < 0.05) more sensitive to peroxynitrite than E. coli 1177. Nitrotyrosine immunoreactivity was observed in infected bladders of both genotypes and in infected kidneys of iNOS+/+ mice. Myeloperoxidase, neuronal (n)NOS, and endothelial (e)NOS immunoreactivity was observed in inflammatory cells of both genotypes. Our results indicate that iNOS/ and iNOS+/+ mice are equally susceptible to E. coli-induced UTI and that the toxicity of NO to E. coli depends on bacterial virulence. Furthermore, myeloperoxidase and nNOS/eNOS may contribute to nitrotyrosine formation in the absence of iNOS.

The Dynamics of Treg/Th17 and the Imbalance of Treg/Th17 in Clonorchis sinensis-Infected Mice

PubMed Central

Hua, Hui; Li, Bo; Zhang, Bo; Yu, Qian; Li, Xiang-Yang; Liu, Ying; Pan, Wei; Liu, Xiang-Ye; Tang, Ren-Xian; Zheng, Kui-Yang

2015-01-01

Clonorchiasis, caused by the liver fluke Clonorchis sinensis, is a chronic parasitic infection regulated by T cell subsets. An imbalance of CD4+CD25+ Foxp3+regulatory T (Treg) and interleukin (IL)-17-secreting T cells (Th17) may control inflammation and play an important role in the pathogenesis of immune evasion. In the present study, we assessed the dynamics of Treg/Th17 and determined whether the Treg/Th17 ratio is altered in C. sinensis-infected mice. The results showed that the percentages of splenic Treg cells in CD4+ T cells were suppressed on day 14 post-infection (PI) but increased on day 56 PI, while Th17 cells were increased on day 56 PI compared with normal control (NC) mice. The Treg/Th17 ratio steadily increased from day 28 to day 56 PI. The hepatic levels of their specific transcription factors (Foxp3 for Treg and RORγt for Th17) were increased in C. sinensis-infected mice from day 14 to 56 PI, and significantly higher than those in NC mice. Meanwhile, serum levels of IL-2 and IL-17 were profoundly increased in C. sinensis-infected mice throughout the experiment; while the concentrations of IL-6 and transforming growth factor β1 (TGF-β1) peaked on day 14 PI, but then decreased on day 28 and 56 PI. Our results provide the first evidence of an increased Treg/Th17 ratio in C. sinensis-infected mice, suggesting that a Treg/Th17 imbalance may play a role in disease outcomes of clonorchiasis. PMID:26599407

Early detection of Trichinella spiralis DNA in the feces of experimentally infected mice by using PCR.

PubMed

Liu, Xiao Lin; Ren, Hua Nan; Shi, Ya Li; Hu, Chen Xi; Song, Yan Yan; Duan, Jiang Yang; Zhang, Hui Ping; Du, Xin Rui; Liu, Ruo Dan; Jiang, Peng; Wang, Zhong Quan; Cui, Jing

2017-02-01

The aim of this study was to detect Trichinella spiralis DNA in mouse feces during the early stages of infection using PCR. The target gene fragment, a 1.6kb repetitive sequence of T. spiralis genome, was amplified by PCR from feces of mice infected with 100 or 300 larvae at 3-24h post infection (hpi) and 2-28dpi. The sensitivity of PCR was 0.016 larvae in feces. The primers used were highly specific for T. spiralis. No cross-reactivity was observed with the DNA of other intestinal helminths. T. spiralis DNA was detected in 100% (12/12) of feces of mice infected with 100 or 300 larvae as early as 3hpi, with the peak detection lasting to 12-24hpi, and then fluctuating before declining gradually. By 28dpi, the detection rate of T. spiralis DNA in feces of the two groups of infected mice decreased to 8.33% and 25%, respectively. PCR detection of T. spiralis DNA in feces is simple and specific; it might be useful for the early diagnosis of Trichinella infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Adverse Events Post Smallpox-Vaccination: Insights from Tail Scarification Infection in Mice with Vaccinia virus

PubMed Central

Mota, Bruno E. F.; Gallardo-Romero, Nadia; Trindade, Giliane; Keckler, M. Shannon; Karem, Kevin; Carroll, Darin; Campos, Marco A.; Vieira, Leda Q.; da Fonseca, Flávio G.; Ferreira, Paulo C. P.; Bonjardim, Cláudio A.; Damon, Inger K.; Kroon, Erna G.

2011-01-01

Adverse events upon smallpox vaccination with fully-replicative strains of Vaccinia virus (VACV) comprise an array of clinical manifestations that occur primarily in immunocompromised patients leading to significant host morbidity/mortality. The expansion of immune-suppressed populations and the possible release of Variola virus as a bioterrorist act have given rise to concerns over vaccination complications should more widespread vaccination be reinitiated. Our goal was to evaluate the components of the host immune system that are sufficient to prevent morbidity/mortality in a murine model of tail scarification, which mimics immunological and clinical features of smallpox vaccination in humans. Infection of C57BL/6 wild-type mice led to a strictly localized infection, with complete viral clearance by day 28 p.i. On the other hand, infection of T and B-cell deficient mice (Rag1 −/−) produced a severe disease, with uncontrolled viral replication at the inoculation site and dissemination to internal organs. Infection of B-cell deficient animals (µMT) produced no mortality. However, viral clearance in µMT animals was delayed compared to WT animals, with detectable viral titers in tail and internal organs late in infection. Treatment of Rag1 −/− with rabbit hyperimmune anti-vaccinia serum had a subtle effect on the morbidity/mortality of this strain, but it was effective in reduce viral titers in ovaries. Finally, NUDE athymic mice showed a similar outcome of infection as Rag1 −/−, and passive transfer of WT T cells to Rag1 −/− animals proved fully effective in preventing morbidity/mortality. These results strongly suggest that both T and B cells are important in the immune response to primary VACV infection in mice, and that T-cells are required to control the infection at the inoculation site and providing help for B-cells to produce antibodies, which help to prevent viral dissemination. These insights might prove helpful to better identify

Adverse events post smallpox-vaccination: insights from tail scarification infection in mice with Vaccinia virus.

PubMed

Mota, Bruno E F; Gallardo-Romero, Nadia; Trindade, Giliane; Keckler, M Shannon; Karem, Kevin; Carroll, Darin; Campos, Marco A; Vieira, Leda Q; da Fonseca, Flávio G; Ferreira, Paulo C P; Bonjardim, Cláudio A; Damon, Inger K; Kroon, Erna G

2011-04-15

Adverse events upon smallpox vaccination with fully-replicative strains of Vaccinia virus (VACV) comprise an array of clinical manifestations that occur primarily in immunocompromised patients leading to significant host morbidity/mortality. The expansion of immune-suppressed populations and the possible release of Variola virus as a bioterrorist act have given rise to concerns over vaccination complications should more widespread vaccination be reinitiated. Our goal was to evaluate the components of the host immune system that are sufficient to prevent morbidity/mortality in a murine model of tail scarification, which mimics immunological and clinical features of smallpox vaccination in humans. Infection of C57BL/6 wild-type mice led to a strictly localized infection, with complete viral clearance by day 28 p.i. On the other hand, infection of T and B-cell deficient mice (Rag1(-/-)) produced a severe disease, with uncontrolled viral replication at the inoculation site and dissemination to internal organs. Infection of B-cell deficient animals (µMT) produced no mortality. However, viral clearance in µMT animals was delayed compared to WT animals, with detectable viral titers in tail and internal organs late in infection. Treatment of Rag1(-/-) with rabbit hyperimmune anti-vaccinia serum had a subtle effect on the morbidity/mortality of this strain, but it was effective in reduce viral titers in ovaries. Finally, NUDE athymic mice showed a similar outcome of infection as Rag1(-/-), and passive transfer of WT T cells to Rag1(-/-) animals proved fully effective in preventing morbidity/mortality. These results strongly suggest that both T and B cells are important in the immune response to primary VACV infection in mice, and that T-cells are required to control the infection at the inoculation site and providing help for B-cells to produce antibodies, which help to prevent viral dissemination. These insights might prove helpful to better identify individuals with

Comparison of the course of infection with Giardia muris in male and female mice.

PubMed

Daniels, C W; Belosevic, M

1995-01-01

The infection with Giardia muris in male and female C57BL/6 mice was characterized by enumerating cyst release in the feces and trophozoite burden in the small intestine. Cyst release differed between males and females during the course of the primary and challenge infections. Males and females released similar numbers of cysts in the feces during the acute phase of the infection. However, the trophozoite burden was significantly higher in males during the same period. Males released cysts in their feces longer than females and trophozoites present in their intestines for a longer period than females. From day 18 of infection the females did not release cysts in their feces, while males continued to do so for at least 60 days. Thus, distinct differences exist between male and female mice in their ability to harbor and eliminate this intestinal parasite.

Development of a multiplex serological assay reveals a worldwide distribution of murine astrovirus infections in laboratory mice.

PubMed

Schmidt, Katja; Butt, Julia; Mauter, Petra; Vogel, Klaus; Erles-Kemna, Andrea; Pawlita, Michael; Nicklas, Werner

2017-01-01

Laboratory mice play a tremendous role in biomedical research in studies on immunology, infection, cancer and therapy. In the course of standardization of mice used in animal experiments, health monitoring constitutes an important instrument towards microbiological standardization. Infections with murine astroviruses (MuAstV) were only recently discovered and are, therefore, still relatively unknown in laboratory animal science. In rodent health monitoring viral infections within a population are commonly assessed in terms of specific antibodies by serological testing, as active infection and excretion of virus is often temporary and can easily be missed. So far only ongoing infections with astroviruses can be detected by PCR. The objective of this work was the development of a sensitive and specific MuAstV multiplex serological assay with a high-throughput capability to be used in routine testing of laboratory mice. Four different MuAstV proteins were recombinantly expressed and used as antigens. The best reacting antigen, the capsid spike protein VP27, was selected and tested with a panel of 400 sera of mice from units with a known MuAstV status. Assay sensitivity and specificity resulted in 98.5% and 100%, respectively, compared to RT-PCR results. Eventually this assay was used to test 5529 serum samples in total, during routine diagnostics at the German Cancer Research Center (DKFZ) in Heidelberg between 2015 and 2017. High sero-prevalence rates of up to 98% were detected in units with open cages indicating that the virus is highly infectious and circulates within these populations virtually infecting all animals regardless of the mouse strain. In addition, data collected from 312 mice purchased from commercial breeders and from 661 mice from 58 research institutes in 15 countries worldwide allowed the conclusion that MuAstV is widespread in contemporary laboratory mouse populations.

The nervous system in genital herpes simplex virus type 2 infections in mice. Lethal panmyelitis or nonlethal demyelinative myelitis or meningitis.

PubMed

Martin, J R; Stoner, G L

1984-11-01

Female mice were inoculated vaginally with the MS strain of herpes simplex virus type 2, and serially positive vaginal cultures were used to confirm infection. The proportion of mice infected and the mortality rate in infected mice decreased with increasing age. In mice 12 weeks old, clinical, neuropathologic, and virologic criteria defined four patterns of disease. Moribund mice had severe genital lesions, hindleg paralysis, and urinary and fecal retention, and most died during the second week of infection. These mice had a panmyelitis with a decreasing gradient of both viral antigen and lesions extending rostrally from the lumbosacral cord into the brain stem. Lesions were about equally distributed in gray and white matter and were characterized by neuronal loss and axonal demyelination, respectively. By contrast, mice with nonfatal infections had mild or no evident genital lesions and a small proportion had mild hindleg weakness. Of these, some mice had demyelinative lesions, particularly in the lower spinal cord but also at higher cord and brain stem levels, whereas others had leptomeningitis. Both of these groups had sacral sensory root abnormalities. A third group of survivors lacked both sensory root and central nervous system abnormalities. This report defines a broader spectrum of disease patterns following infection by a natural route than has been previously appreciated. It provides the first evidence that nonfatal herpes simplex virus type 2 infection by a peripheral route can produce central nervous system demyelination. It indicates that in aseptic meningitis with this agent, the route of virus spread to the central nervous system is neural and not hematogenous. Finally, the antigenic and pathologic observations presented here complement and confirm the virus isolation data and pathologic findings of others that genital herpes simplex virus type 2 infection causes ascending infection in the peripheral and central nervous system.

Effect of cold water-induced stress on immune response, pathology and fertility in mice during Chlamydia muridarum genital infection.

PubMed

Belay, Tesfaye; Woart, Anthony; Graffeo, Vincent

2017-07-31

Genital infection by Chlamydia trachomatis is the most common bacterial sexually transmitted disease worldwide. It causes serious reproductive health complications, including pelvic inflammatory disease and infertility. Stress is implicated as a risk factor for various infections; however, its effect on chlamydia genital infection is unknown. We previously showed that repeated exposure of mice to cold water results in increased severity of chlamydia genital infection. In this study, cold water-induced stress resulted in (i) elevated levels of norepinephrine (NE) and epinephrine in the spleen and genital tract of stressed mice; (ii) elevated IL-1β, TNF-α, IL-6 and nitric oxide production in macrophage-rich peritoneal cells of mice; (iii) supplement of NE in vitro exerts an immunosuppressive effect on splenic T-cell production of cytokines; (iv) decreased C. muridarum shedding in the genital tract of β1Adr/β2Adr receptor KO mice; and (v) a higher rate of infertility in infected mice. These results suggest that cold water stress induces the production of catecholamines, which may play a critical role in the modulation of the immune system leading to increased intensity of C. muridarum genital infection. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

MAPK phosphotase 5 deficiency contributes to protection against blood-stage Plasmodium yoelii 17XL infection in mice.

PubMed

Cheng, Qianqian; Zhang, Qingfeng; Xu, Xindong; Yin, Lan; Sun, Lin; Lin, Xin; Dong, Chen; Pan, Weiqing

2014-04-15

Cell-mediated immunity plays a crucial role in the development of host resistance to asexual blood-stage malaria infection. However, little is known of the regulatory factors involved in this process. In this study, we investigated the impact of MAPK phosphotase 5 (MKP5) on protective immunity against a lethal Plasmodium yoelii 17XL blood-stage infection using MKP5 knockout C57BL/6 mice. Compared with wild-type control mice, MKP5 knockout mice developed significantly lower parasite burdens with prolonged survival times. We found that this phenomenon correlated with a rapid and strong IFN-γ-dependent cellular immune response during the acute phase of infection. Inactivation of IFN-γ by the administration of a neutralizing Ab significantly reduced the protective effects in MKP5 knockout mice. By analyzing IFN-γ production in innate and adaptive lymphocyte subsets, we observed that MKP5 deficiency specifically enhanced the IFN-γ response mediated by CD4+ T cells, which was attributable to the increased stimulatory capacity of splenic CD11c+ dendritic cells. Furthermore, following vaccination with whole blood-stage soluble plasmodial Ag, MKP5 knockout mice acquired strongly enhanced Ag-specific immune responses and a higher level of protection against subsequent P. yoelii 17XL challenge. Finally, we found the enhanced response mediated by MKP5 deficiency resulted in a lethal consequence in mice when infected with nonlethal P. yoelii 17XNL. Thus, our data indicate that MKP5 is a potential regulator of immune resistance against Plasmodium infection in mice, and that an understanding of the role of MKP5 in manipulating anti-malaria immunity may provide valuable information on the development of better control strategies for human malaria.

Theiler's virus-infected L-selectin-deficient mice have decreased infiltration of CD8(+) T lymphocytes in central nervous system but clear the virus.

PubMed

Zhang, X; Brewer, L; Walcheck, B; Johnson, A; Pease, L R; Njenga, M K

2001-06-01

Mice with targeted deletion of L-selectin gene (L-sel(-/-)) were used to investigate the role of adhesion molecule in immunologic responses following virus infection in the central nervous system (CNS). L-Sel(-/-) mice from a resistant H-2(b) genetic background and parental wild-type H-2(b) (C57BL/6) mice were infected with Theiler's murine encephalomyelitis virus (TMEV) intracerebrally and the kinetics of virus replication and infiltration of immune cells in the CNS determined. The levels of infectious TMEV, as measured by plaque assay at 3, 7, 14, and 28 days after infection were between 4 and 6 log(10) PFU of virus per gram of CNS tissues at days 3 and 7 post-infection, and then decreased to undetectable levels by day 14 after infection in both strains of mice. The L-sel(-/-) mice had decreased numbers of CD8(+) T lymphocytes (17.72%+/-2.4) infiltrating into the CNS at 7 days post-infection when compared to wild-type mice (31.02%+/-7.5). In addition, the L-sel(-/-) mice had significantly lower levels of TMEV-specific serum IgG resulting in lower virus neutralizing activity of the serum when compared to wild-type mice. However, the L-sel(-/-) mice had 2.5-fold increase in B lymphocytes in the CNS (8.29%+/-1.1) when compared to wild-type mice (3.2%+/-0.4). Taken together, these data indicate that L-selectin plays a role in recruitment of B and CD8(+) T lymphocytes into the CNS following virus infection, which, however, did not affect the ability of the mice to clear TMEV infection.

Effects of gamma radiation and azathioprine on Brucella abortus infection in BALB/c mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elzer, P.H.; Rowe, G.E.; Enright, F.M.

Sublethal irradiation of BALB/c mice 4 hours prior to inoculation with 5 {times} 10(4) virulent Brucella abortus, caused significant (P less than 0.01) reductions in bacterial numbers in comparison with numbers in unirradiated controls. Numbers of brucellae in the spleen were significantly lower by 5 days after inoculation and decreased thereafter, so that at 2 and 3 weeks after inoculation, there were up to 1,000-fold fewer organisms in the spleen of irradiated mice. The number of brucellae in the spleen increased in irradiated mice thereafter. The course of events in the liver was similar, but developed more slowly, and peakmore » differences in bacterial numbers were about 1 log less. These phenomena were not attributable to differences in implantation of brucellae in the liver or spleen, nor to an abnormal distribution of organisms in other organs of irradiated mice. Irradiation of mice during the plateau phase of infection also resulted in significant (P less than 0.05) reductions in bacterial counts in the spleen during the succeeding 4 weeks. Macrophage activation in the spleen, measured by a Listeria monocytogenes-killing assay, was significantly (P less than 0.01) increased by irradiation alone at 1 week after inoculation and at that time was significantly (P less than 0.01) greater in B abortus-infected, irradiated mice than in B abortus-infected controls. Histologic, cytologic, and immunologic studies revealed that the decrease in numbers of organisms between 1 and 2 weeks after inoculation in irradiated mice occurred at a time when their immune response to B abortus was suppressed and when numbers of neutrophils and monocytes infiltrating the spleen were significantly (P less than 0.01) diminished.« less

Exercise Improves Host Response to Influenza Viral Infection in Obese and Non-Obese Mice through Different Mechanisms

PubMed Central

Warren, Kristi J.; Olson, Molly M.; Thompson, Nicholas J.; Cahill, Mackenzie L.; Wyatt, Todd A.; Yoon, Kyoungjin J.; Loiacono, Christina M.; Kohut, Marian L.

2015-01-01

Obesity has been associated with greater severity of influenza virus infection and impaired host defense. Exercise may confer health benefits even when weight loss is not achieved, but it has not been determined if regular exercise improves immune defense against influenza A virus (IAV) in the obese condition. In this study, diet-induced obese mice and lean control mice exercised for eight weeks followed by influenza viral infection. Exercise reduced disease severity in both obese and non-obese mice, but the mechanisms differed. Exercise reversed the obesity-associated delay in bronchoalveolar-lavage (BAL) cell infiltration, restored BAL cytokine and chemokine production, and increased ciliary beat frequency and IFNα-related gene expression. In non-obese mice, exercise treatment reduced lung viral load, increased Type-I-IFN-related gene expression early during infection, but reduced BAL inflammatory cytokines and chemokines. In both obese and non-obese mice, exercise increased serum anti-influenza virus specific IgG2c antibody, increased CD8+ T cell percentage in BAL, and reduced TNFα by influenza viral NP-peptide-responding CD8+ T cells. Overall, the results suggest that exercise “restores” the immune response of obese mice to a phenotype similar to non-obese mice by improving the delay in immune activation. In contrast, in non-obese mice exercise treatment results in an early reduction in lung viral load and limited inflammatory response. PMID:26110868

Therapeutic effect of cefozopran (SCE-2787), a new parenteral cephalosporin, against experimental infections in mice.

PubMed Central

Iizawa, Y; Okonogi, K; Hayashi, R; Iwahi, T; Yamazaki, T; Imada, A

1993-01-01

The therapeutic effect of cefozopran (SCE-2787), a new semisynthetic parenteral cephalosporin, against experimental infections in mice was examined. Cefozopran was more effective than cefpiramide and was as effective as ceftazidime and cefpirome against acute respiratory tract infections caused by Klebsiella pneumoniae DT-S. In the model of chronic respiratory tract infection caused by K. pneumoniae 27, cefozopran was as effective as ceftazidime. The therapeutic effect of cefozopran against urinary tract infections caused by Pseudomonas aeruginosa P9 was superior to that of cefpirome and was equal to those of ceftazidime and cefclidin. In addition, cefozopran was more effective than ceftazidime and was as effective as flomoxef in a thigh muscle infection caused by methicillin-sensitive Staphylococcus aureus 308A-1. Against thigh muscle infections caused by methicillin-resistant S. aureus N133, cefozopran was the most effective agent. The potent therapeutic effect of cefozopran in those experimental infections in mice suggests that it would be effective against respiratory tract, urinary tract, and soft tissue infections caused by a variety of gram-positive and gram-negative bacteria in humans. PMID:8431004

Toxoplasma gondii Infection in Mice Impairs Long-Term Fear Memory Consolidation through Dysfunction of the Cortex and Amygdala.

PubMed

Ihara, Fumiaki; Nishimura, Maki; Muroi, Yoshikage; Mahmoud, Motamed Elsayed; Yokoyama, Naoaki; Nagamune, Kisaburo; Nishikawa, Yoshifumi

2016-10-01

Chronic infection with Toxoplasma gondii becomes established in tissues of the central nervous system, where parasites may directly or indirectly modulate neuronal function. Epidemiological studies have revealed that chronic infection in humans is a risk factor for developing mental diseases. However, the mechanisms underlying parasite-induced neuronal dysfunction in the brain remain unclear. Here, we examined memory associated with conditioned fear in mice and found that T. gondii infection impairs consolidation of conditioned fear memory. To examine the brain pathology induced by T. gondii infection, we analyzed the parasite load and histopathological changes. T. gondii infects all brain areas, yet the cortex exhibits more severe tissue damage than other regions. We measured neurotransmitter levels in the cortex and amygdala because these regions are involved in fear memory expression. The levels of dopamine metabolites but not those of dopamine were increased in the cortex of infected mice compared with those in the cortex of uninfected mice. In contrast, serotonin levels were decreased in the amygdala and norepinephrine levels were decreased in the cortex and amygdala of infected mice. The levels of cortical dopamine metabolites were associated with the time spent freezing in the fear-conditioning test. These results suggest that T. gondii infection affects fear memory through dysfunction of the cortex and amygdala. Our findings provide insight into the mechanisms underlying the neurological changes seen during T. gondii infection. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

A recombinant bivalent fusion protein rVE confers active and passive protection against Yersinia enterocolitica infection in mice.

PubMed

Singh, Amit Kumar; Kingston, Joseph Jeyabalaji; Murali, Harishchandra Sripathy; Batra, Harsh Vardhan

2014-03-05

In the present study, a bivalent chimeric protein rVE comprising immunologically active domains of Yersinia pestis LcrV and YopE was assessed for its prophylactic abilities against Yersinia enterocolitica O:8 infection in murine model. Mice immunized with rVE elicited significantly higher antibody titers with substantial contribution from the rV component (3:1 ratio). Robust and significant resistance to Y. enterocolitica infection with 100% survival (P<0.001) was seen in rVE vaccinated mice when intra peritoneal (I.P.) challenged with 10(8)CFU of Y. enterocolitica O:8 against the 75%, 60% and 75% survival seen in mice immunized with rV, rE, rV+rE, respectively. Macrophage monolayer supplemented with anti-rVE polysera illustrated efficient protection (89.41% survival) against challenge of Y. enterocolitica O:8. In contrast to sera from sham-immunized mice, immunization with anti-rVE polysera provided complete protection to BALB/c mice against I.P. challenge with 10(8)CFU of Y. enterocolitica O:8 and developed no conspicuous signs of infection in necropsy. The histopathological analysis of microtome sections confirmed significantly reduced lesion size or no lesion in liver and intestine upon infection in anti-rVE immunized mice. The findings from this study demonstrated the fusion protein rVE as a potential candidate subunit vaccine and showed the functional role of antibodies in protection against Y. enterocolitica infections. Copyright © 2014 Elsevier Ltd. All rights reserved.

Defined bacterial populations in the rumens of gnotobiotic lambs.

PubMed

Lysons, R J; Alexander, T J; Wellstead, P D; Hobson, P N; Mann, S O; Stewart, C S

1976-06-01

Five gnotobiotic lambs were fed on sterile diets until they were killed at 13 to 21 weeks of age. They were dosed orally with different combinations of 11 species of rumen bacteria. The biochemical reactions of each of the bacteria inoculated had been determined in pure culture in vitro, and they were chosen to perform the main reactions known to be associated with digestion in the normal mature rumen. Two of the bacteria could not be reisolated, but the remainder had established readily in the rumen, forming stable, mixed, defined populations. The total numbers of bacteria in the rumen, and the viable counts of most of the individual species were comparable to those of normal sheep. The concentration of volatile fatty acids was lower, however, and in four of the lambs there was a higher proportion of butyric acid and a lower proportion of propionic acid than in normal sheep. Cellulolytic, ureolytic, and methanogenic activities appeared to be taking place and lactate-utilizing bacteria appeared to reverse the accumulation of lactate which resulted from the activity of lactate-producing bacteria. Some of the bacteria also established at high levels in the caecum.

Suppression of host resistance against Listeria monocytogenes infection by 15-deoxyspergualin in mice.

PubMed Central

Nakane, A; Numata, A; Minagawa, T

1990-01-01

The effects of 15-deoxyspergualin (DSG), an immunosuppressive agent, on host resistance against Listeria monocytogenes were studied in mice. Administration of DSG in the early phase of infection resulted in fatal listeriosis by preventing acquired anti-listerial resistance, even though the infectious dose was sublethal for the untreated controls. In contrast, DSG treatment started after development of the acquired immunity was ineffective. Endogenous production of interferon-gamma (IFN-gamma) and tumour necrosis factor (TNF) in the bloodstreams induced by the infection was normal in DSG-treated mice. Nevertheless, augmentation of macrophage functions such as expression of major histocompatibility complex (MHC) class II antigens, phagocytic activity and listericidal activity induced by the infection was abrogated by DSG treatment. These results suggest that the inhibitory effect of DSG on anti-listerial resistance might be different from cyclosporine A (CsA). PMID:2126253

Hyperoxic exposure of immature mice increases the inflammatory response to subsequent rhinovirus infection: Association with danger signals

PubMed Central

Cui, Tracy X.; Maheshwer, Bhargavi; Hong, Jun Y.; Goldsmith, Adam M.; Bentley, J. Kelley; Popova, Antonia P.

2016-01-01

Infants with a history of prematurity and bronchopulmonary dysplasia (BPD) have a high risk of asthma and viral-induced exacerbations later in life. We hypothesized that hyperoxic exposure, a predisposing factor to BPD, modulates the innate immune response, producing an exaggerated pro-inflammatory reaction to viral infection. Two-to-3 day-old C57BL/6J mice were exposed to air or 75% oxygen for 14 days. Mice were infected intranasally with rhinovirus (RV) immediately after O2 exposure. Lung mRNA and protein expression, histology, dendritic cells (DCs) and airways responsiveness were assessed 1-12 days after infection. Tracheal aspirates from premature human infants were collected for mRNA detection. Hyperoxia increased lung IL-12 expression which persisted up to 12 days post-exposure. Hyperoxia-exposed RV-infected mice showed further increases in IL-12 and increased expression of IFN-γ, TNF-α, CCL2, CCL3 and CCL4, as well as increased airway inflammation and responsiveness. In RV-infected, air-exposed mice the response was not significant. Induced IL-12 expression in hyperoxia-exposed, RV-infected mice was associated with increased IL-12-producing CD103+ lung DCs. Hyperoxia also increased expression of Clec9a, a CD103+ DC-specific damaged cell-recognition molecule. Hyperoxia increased levels of ATP metabolites and expression of adenosine receptor A1, further evidence of cell damage and related signaling. In human preterm infants, tracheal aspirate Clec9a expression positively correlated with the level of prematurity. Hyperoxic exposure increases the activation of CD103+, Clec9a+ DCs, leading to increased inflammation and airway hyperresponsiveness upon RV infection. In premature infants, danger signal-induced DC activation may promote pro-inflammatory airway responses, thereby increasing respiratory morbidity. PMID:27183577

Characteristics of Viruses Derived from Nude Mice with Persistent Measles Virus Infection

PubMed Central

Hashimoto, Koichi; Watanabe, Masahiro; Ohara, Shinichiro; Sato, Masatoki; Kawasaki, Yukihiko; Hashimoto, Yuko; Hosoya, Mitsuaki

2013-01-01

Measles virus (MV) isolates from patients with subacute sclerosing panencephalitis (SSPE) differ from wild-type MV virologically. However, few animal models have reported viruses with characteristics of the SSPE virus. The MV Edmonston strain was inoculated into the subarachnoid space of nude mice. All nude mice displayed weight loss and required euthanasia, with a mean survival duration of 73.2 days. The viral load in the brain was 4- to 400-fold higher than the inoculated load, and brain infection was confirmed by immunostaining. Gene sequencing of the viruses revealed that amino acid mutations occurred more frequently in matrix proteins. The most common mutation was a uridine-to-cytosine transition. The virus exhibited lower free virus particle formation ability than the Edmonston strain. When nude mice were challenged with 2 × 102 PFU of the brain-derived virus, the mean survival duration was 34.7 days, which was significantly shorter than that of the mice challenged with 4 × 104 PFU of the Edmonston strain (P < 0.01). This study indicated that MV in a nude mouse model of persistent infection exhibited characteristics of the SSPE virus. This model may prove useful in elucidating the pathogenic mechanism of SSPE and developing potential therapeutics. PMID:23345518

Characteristics of viruses derived from nude mice with persistent measles virus infection.

PubMed

Abe, Yusaku; Hashimoto, Koichi; Watanabe, Masahiro; Ohara, Shinichiro; Sato, Masatoki; Kawasaki, Yukihiko; Hashimoto, Yuko; Hosoya, Mitsuaki

2013-04-01

Measles virus (MV) isolates from patients with subacute sclerosing panencephalitis (SSPE) differ from wild-type MV virologically. However, few animal models have reported viruses with characteristics of the SSPE virus. The MV Edmonston strain was inoculated into the subarachnoid space of nude mice. All nude mice displayed weight loss and required euthanasia, with a mean survival duration of 73.2 days. The viral load in the brain was 4- to 400-fold higher than the inoculated load, and brain infection was confirmed by immunostaining. Gene sequencing of the viruses revealed that amino acid mutations occurred more frequently in matrix proteins. The most common mutation was a uridine-to-cytosine transition. The virus exhibited lower free virus particle formation ability than the Edmonston strain. When nude mice were challenged with 2 × 10(2) PFU of the brain-derived virus, the mean survival duration was 34.7 days, which was significantly shorter than that of the mice challenged with 4 × 10(4) PFU of the Edmonston strain (P < 0.01). This study indicated that MV in a nude mouse model of persistent infection exhibited characteristics of the SSPE virus. This model may prove useful in elucidating the pathogenic mechanism of SSPE and developing potential therapeutics.

Effects of a traditional Chinese herbal medicine, Kanzo-bushi-to, on the resistance of thermally injured mice infected with herpes simplex virus type 1.

PubMed

Matsuo, R; Ball, M A; Kobayashi, M; Herndon, D N; Pollard, R B; Suzuki, F

1994-10-01

The protective effect of Kanzo-bushi-to (TJS-038) was investigated on the opportunistic infection of herpes simplex virus type 1 (HSV) in thermally injured mice (TI-Mice). We have previously reported that TI-Mice were approximately 100 times more susceptible to HSV infection than normal mice (N-Mice) and that CD8+ suppressor T (ST)-cells induced by burn injury were involved in causing this increased susceptibility of TI-Mice. Increased susceptibility of TI-Mice to the infection was reversed to the levels observed in N-Mice when TI-Mice were treated intraperitoneally with TJS-038 at a dose of 5 mg/kg 1 and 4 days after thermal injury. The activity of ST-cells was greatly decreased in TI-Mice treated with TJS-038. The generation of Vicia villosa lectin-adherent CD4+ CD28+ TCR-alpha/beta+ contrasuppressor T (Contra-ST)-cells associated with the appearance of ST-cells was expanded and occurred earlier in spleens of TJS-038-treated TI-Mice as compared with that of untreated TI-Mice. The improved resistance of TJS-038-treated TI-Mice to the infection was transferred to untreated TI-Mice by adoptive transfer of Contra-ST-cells prepared from TJS-038-treated TI-Mice. These results suggest that TJS-038 may restore the resistance of TI-Mice to the HSV infection through the expanded generation of Contra-ST-cells.

Induction of virus-specific effector immune cell response limits virus replication and severe disease in mice infected with non-lethal West Nile virus Eg101 strain.

PubMed

Kumar, Mukesh; Roe, Kelsey; O'Connell, Maile; Nerurkar, Vivek R

2015-09-22

West Nile virus (WNV) is a neurotropic flavivirus that has emerged globally as a significant cause of viral encephalitis in humans. Herein, we investigated the immunological responses induced by two phylogenetically related WNV strains of lineage 1, WNV NY99, and WNV Eg101. Eight-week-old C57BL/6J mice were inoculated with WNV NY99 or WNV Eg101 and mortality, virus burden in the periphery and brain, type 1 interferon response, WNV-specific antibodies, leukocyte infiltration, and inflammatory responses were analyzed. As expected, WNV NY99 infected mice demonstrated high morbidity and mortality, whereas no morbidity and mortality was observed in WNV Eg101 infected mice. Virus titers were comparable in the serum of both WNV NY99 and WNV Eg101 infected mice at day 3 after inoculation; however, at day 6, the virus was cleared from WNV Eg101 infected mice but the virus titer remained high in the WNV NY99 infected mice. Virus was detected in the brains of both WNV NY99 and Eg101 infected mice, albeit significantly higher in the brains of WNV NY99 infected mice. Surprisingly, levels of type 1 interferon and WNV-specific antibodies were significantly higher in the serum and brains of WNV NY99 infected mice. Similarly, protein levels of multiple cytokines and chemokines were significantly higher in the serum and brains of WNV NY99 infected mice. In contrast, we observed significantly higher numbers of innate and adaptive immune cells in the spleens and brains of WNV Eg101 infected mice. Moreover, total number and percentage of IFN-γ and TNF-α producing WNV-specific CD8(+) T cells were also significantly high in WNV Eg101 infected mice. Our data demonstrate that induction of virus-specific effector immune cell response limits virus replication and severe WNV disease in Eg101 infected mice. Our data also demonstrate an inverse correlation between leukocyte accumulation and production of pro-inflammatory mediators in WNV-infected mice. Moreover, increased production of pro

Borrelia-primed and -infected mice deficient of interleukin-17 develop arthritis after neutralization of gamma-interferon.

PubMed

Kuo, Joseph; Warner, Thomas F; Schell, Ronald F

2017-03-01

The immune mechanisms responsible for development of Lyme arthritis are partially understood with interleukin-17 (IL-17) and gamma-interferon (IFN-γ) playing a generally accepted role. Elevated levels of IL-17 and/or IFN-γ have been reported in samples from human Lyme arthritis patients and experimental mice. In addition, IL-17 and IFN-γ have been implicated in the onset of arthritis in Borrelia-primed and -infected C57BL/6 mice. Recently, we showed that IL-17-deficient mice developed swelling and histopathological changes consistent with arthritis in the presence of high levels of IFN-γ. We hypothesized that neutralization of IFN-γ in IL-17-deficient mice would inhibit Borrelia-induced arthritis. Our results, however, showed that swelling of the hind paws and histopathological changes of arthritis did not differ between Borrelia-primed and -infected IL-17-deficient and wild-type mice with or without neutralization of IFN-γ. We also found higher levels of tumor necrosis factor alpha (TNF-α) and IL-6 in the popliteal lymph node cells of Borrelia-primed and -infected IL-17-deficient mice after neutralization of IFN-γ. These results suggest that multiple cytokines interact in the development of Borrelia-induced arthritis. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Galectins expressed differently in genetically susceptible C57BL/6 and resistant BALB/c mice during acute ocular Toxoplasma gondii infection.

PubMed

Chen, S-J; Zhang, Y-X; Huang, S-G; Lu, F-L

2017-07-01

Ocular toxoplasmosis (OT) caused by Toxoplasma gondii is a major cause of infectious uveitis, however little is known about its immunopathological mechanism. Susceptible C57BL/6 (B6) and resistant BALB/c mice were intravitreally infected with 500 tachyzoites of the RH strain of T. gondii. B6 mice showed more severe ocular pathology and higher parasite loads in the eyes. The levels of galectin (Gal)-9 and its receptors (Tim-3 and CD137), interferon (IFN)-γ, IL-6 and IL-10 were significantly higher in the eyes of B6 mice than those of BALB/c mice; however, the levels of IFN-α and -β were significantly decreased in the eyes and CLNs of B6 mice but significantly increased in BALB/c mice after infection. After blockage of galectin-receptor interactions by α-lactose, neither ocular immunopathology nor parasite loads were different from those of infected BALB/c mice without α-lactose treatment. Although the expressions of Gal-9/receptor were significantly increased in B6 mice and Gal-1 and -3 were upregulated in both strains of mice upon ocular T. gondii infection, blockage of galectins did not change the ocular pathogenesis of genetic resistant BALB/c mice. However, IFN-α and -β were differently expressed in B6 and BALB/c mice, suggesting that type I IFNs may play a protective role in experimental OT.

Effects of the hindlimb-unloading model of spaceflight conditions on resistance of mice to infection with Klebsiella pneumoniae

NASA Technical Reports Server (NTRS)

Belay, Tesfaye; Aviles, Hernan; Vance, Monique; Fountain, Kimberly; Sonnenfeld, Gerald

2002-01-01

BACKGROUND: It has been well documented in several studies that many immunologic parameters are altered in experimental animals and human subjects who have flown in space. However, it is not fully known whether these immunologic changes could result in increased susceptibility to infection. Hindlimb (antiorthostatic) unloading of rodents has been used successfully to simulate some of the effects of spaceflight on physiologic systems. OBJECTIVE: The objective of this study was to determine the effect of hindlimb unloading on the outcome of Klebsiella pneumoniae infection in mice. METHODS: Hindlimb-unloaded, hindlimb-restrained, and control mice were intraperitoneally infected with one 50% lethal dose of K pneumoniae 2 days after suspension. Mortality and bacterial load in several organs were compared among the groups. RESULTS: Unloaded mice showed significantly increased mortality and reduced mean time to death compared with that seen in the control groups. Kinetics of bacterial growth with smaller infective doses revealed that control mice were able to clear bacteria from the organs after 30 hours. In contrast, unloaded mice had continued bacterial growth at the same time point. CONCLUSION: The results of this study suggest that hindlimb unloading might enhance the dissemination of K pneumoniae, leading to increased mortality. The complex physiologic changes observed during hindlimb unloading, including stress, have a key role in the pathophysiology of this infection.

Aged mice display an altered pulmonary host response to Francisella tularensis live vaccine strain (LVS) infections

PubMed Central

CA, Mares; SS, Ojeda; Q, Li; EG, Morris; JJ, Coalson; JM, Teale

2012-01-01

Aging is a complex phenomenon that has been shown to affect many organ systems including the innate and adaptive immune systems. The current study was designed to examine the potential effect of immunosenescence on the pulmonary immune response using a Francisella tularensis live vaccine strain (LVS) inhalation infection model. F. tularensis is a gram-negative intracellular pathogen that can cause a severe pneumonia.In this study both young (8-12 week old) and aged (20-24 month old) mice were infected intranasally with LVS. Lung tissues from young and aged mice were used to assess pathology, recruitment of immune cell types and cytokine expression levels at various times post infection. Bacterial burdens were also assessed. Interestingly, the lungs of aged animals harbored fewer organisms at early time points of infection (day 1, day 3) compared with their younger counterparts. In addition, only aged animals displayed small perivascular aggregates at these early time points that appeared mostly mononuclear in nature. However, the kinetics of infiltrating polymorphonuclear neutrophils (PMNs) and increased cytokine levels measured in the bronchial alveolar lavage fluid (BALF) were delayed in infected aged animals relative to young infected animals with neutrophils appearing at day 5 post infection (PI) in the aged animals as opposed to day 3 PI in the young infected animals. Also evident were alterations in the ratios of mononuclear to PMNs at distinct post infection times. The above evidence indicates that aged mice elicit an altered immune response in the lung to respiratory Francisella tularensis LVS infections compared to their younger counterparts. PMID:19825409

Stimulation of myelopoiesis in Listeria monocytogenes-infected mice by an aggregated polymer isolated from Aspergillus oryzae.

PubMed

de Melo, A; Justo, G Z; de Souza Queiroz, M L

2001-01-01

In this work, we investigated the effects of the proteic aggregated polymer of magnesium ammonium phospholinoleate-palmitoleate anhydride (MAPA) isolated from Aspergillus oryzae on the growth and differentiation of bone marrow granulocyte-macrophage progenitor cells (CFU-GM) in Listeriamonocytogenes-infected mice. A significant reduction in the CFU-GM number was observed in the initial phase of infection with a sublethal dose of Listeria. Treatment of mice with 0.5, 2.0 and 5.0 mg/kg MAPA for 7 days prior to infection significantly stimulated myelopoiesis in a dose-dependent manner. Moreover, treatment with 0.5 and 5.0 mg/kg MAPA resulted in 30% and 40% cures of mice lethally infected with Listeria, respectively. MAPA added directly to the culture dishes hardly affected colony formation by bone marrow cells, suggesting an indirect effect ofthis compound on myelopoiesis in vivo. In summary, the data show that MAPA can modulate the CFU-GM generation and antibacterial resistance in listeriosis. As the ability of hematopoietic tissues to produce phagocytes is of particular significance to mediate resistance to Listeria, the promotion of bone marrow CFU-GM by MAPA may contribute to a rapid restoration of phagocyte numbers in infected sites, thus mitigating the course of infection.

Endothelin-1 Treatment Induces an Experimental Cerebral Malaria-Like Syndrome in C57BL/6 Mice Infected with Plasmodium berghei NK65.

PubMed

Martins, Yuri C; Freeman, Brandi D; Akide Ndunge, Oscar B; Weiss, Louis M; Tanowitz, Herbert B; Desruisseaux, Mahalia S

2016-11-01

Plasmodium berghei ANKA infection of C57BL/6 mice is a widely used model of experimental cerebral malaria (ECM). By contrast, the nonneurotropic P. berghei NK65 (PbN) causes severe malarial disease in C57BL/6 mice but does not cause ECM. Previous studies suggest that endothelin-1 (ET-1) contributes to the pathogenesis of ECM. In this study, we characterize the role of ET-1 on ECM vascular dysfunction. Mice infected with 10 6 PbN-parasitized red blood cells were treated with either ET-1 or saline from 2 to 8 days postinfection (dpi). Plasmodium berghei ANKA-infected mice served as the positive control. ET-1-treated PbN-infected mice exhibited neurological signs, hypothermia, and behavioral alterations characteristic of ECM, dying 4 to 8 dpi. Parasitemia was not affected by ET-1 treatment. Saline-treated PbN-infected mice did not display ECM, surviving until 12 dpi. ET-1-treated PbN-infected mice displayed leukocyte adhesion to the vascular endothelia and petechial hemorrhages throughout the brain at 6 dpi. Intravital microscopic images demonstrated significant brain arteriolar vessel constriction, decreased functional capillary density, and increased blood-brain barrier permeability. These alterations were not present in either ET-1-treated uninfected or saline-treated PbN-infected mice. In summary, ET-1 treatment of PbN-infected mice induced an ECM-like syndrome, causing brain vasoconstriction, adherence of activated leukocytes in the cerebral microvasculature, and blood-brain barrier leakage, indicating that ET-1 is involved in the genesis of brain microvascular alterations that are the hallmark of ECM. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Serum antibody responses by male and female C57Bl/6 mice infected with Giardia muris.

PubMed

Daniels, C W; Belosevic, M

1994-09-01

We compared the levels of serum antibodies in male and female C57Bl/6 mice during the primary and after challenge infection with Giardia muris. Male mice began passing cysts in their faeces earlier than females, and were shedding cysts for over 60 days, while females stopped shedding cysts by day 20 after infection. In both males and females there were significant increases in parasite-specific IgM 10 and 20 days after infection. No differences in parasite-specific serum IgA were observed until 40 days after infection. Parasite-specific IgG (whole) levels were elevated on days 20 and 40 in females, while males showed no significant increases. In addition, females had a much stronger IgG2b and IgG3 response than males. After challenge with either cysts or soluble parasite protein only the females had significant increases in specific anti-parasite IgG2b. Our data show differential ability of males and females to control the infection with G. muris is paralleled by a difference in the anti-parasite serum IgG response of the mice.

Intraperitoneal prophylaxis with CpG oligodeoxynucleotides protects neutropenic mice against intracerebral Escherichia coli K1 infection.

PubMed

Ribes, Sandra; Meister, Tanja; Ott, Martina; Redlich, Sandra; Janova, Hana; Hanisch, Uwe-Karsten; Nessler, Stefan; Nau, Roland

2014-01-23

Prophylaxis with unmethylated cytosine phosphate guanidine (CpG) oligodeoxynucleotides (ODN) protects against several systemic experimental infections. Escherichia coli is a major cause of Gram-negative neonatal bacterial meningitis and also causes meningitis and meningoencephalitis in older and immunocompromised patients. Wild-type (wt) and Toll-like receptor 9 (TLR9)-deficient mice were rendered neutropenic by intraperitoneal administration of the anti-Ly-6G monoclonal antibody. Immunocompetent and neutropenic mice received intraperitoneal CpG ODN or vehicle 72 h prior to induction of E. coli K1 meningoencephalitis. Pre-treatment with CpG ODN significantly increased survival of neutropenic wt mice from 33% to 75% (P = 0.0003) but did not protect neutropenic TLR9-/- mice. The protective effect of CpG ODN was associated with an enhanced production of interleukin (IL)-12/IL-23p40 with sustained increased levels in serum and spleen at least for 17 days after conditioning compared to buffer-treated animals. CpG-treated neutropenic wt mice showed reduced bacterial concentrations and increased recruitment of Ly6ChighCCR2+ monocytes in brain and spleen 42 h after infection. The levels of macrophage inflammatory protein 1α (MIP-1α) and interferon gamma (IFN-γ) in spleen were higher 42 h after infection in CpG-treated compared to buffer-treated neutropenic animals. In immunocompetent mice, prophylaxis with CpG ODN did not significantly increase survival compared to the buffer group (60% vs. 45%, P = 0.2). These findings suggest that systemic administration of CpG ODN may help to prevent bacterial CNS infections in immunocompromised individuals.

Thymidine Kinase-Negative Herpes Simplex Virus 1 Can Efficiently Establish Persistent Infection in Neural Tissues of Nude Mice.

PubMed

Huang, Chih-Yu; Yao, Hui-Wen; Wang, Li-Chiu; Shen, Fang-Hsiu; Hsu, Sheng-Min; Chen, Shun-Hua

2017-02-15

Herpes simplex virus 1 (HSV-1) establishes latency in neural tissues of immunocompetent mice but persists in both peripheral and neural tissues of lymphocyte-deficient mice. Thymidine kinase (TK) is believed to be essential for HSV-1 to persist in neural tissues of immunocompromised mice, because infectious virus of a mutant with defects in both TK and UL24 is detected only in peripheral tissues, but not in neural tissues, of severe combined immunodeficiency mice (T. Valyi-Nagy, R. M. Gesser, B. Raengsakulrach, S. L. Deshmane, B. P. Randazzo, A. J. Dillner, and N. W. Fraser, Virology 199:484-490, 1994, https://doi.org/10.1006/viro.1994.1150). Here we find infiltration of CD4 and CD8 T cells in peripheral and neural tissues of mice infected with a TK-negative mutant. We therefore investigated the significance of viral TK and host T cells for HSV-1 to persist in neural tissues using three genetically engineered mutants with defects in only TK or in both TK and UL24 and two strains of nude mice. Surprisingly, all three mutants establish persistent infection in up to 100% of brain stems and 93% of trigeminal ganglia of adult nude mice at 28 days postinfection, as measured by the recovery of infectious virus. Thus, in mouse neural tissues, host T cells block persistent HSV-1 infection, and viral TK is dispensable for the virus to establish persistent infection. Furthermore, we found 30- to 200-fold more virus in neural tissues than in the eye and detected glycoprotein C, a true late viral antigen, in brainstem neurons of nude mice persistently infected with the TK-negative mutant, suggesting that adult mouse neurons can support the replication of TK-negative HSV-1. Acyclovir is used to treat herpes simplex virus 1 (HSV-1)-infected immunocompromised patients, but treatment is hindered by the emergence of drug-resistant viruses, mostly those with mutations in viral thymidine kinase (TK), which activates acyclovir. TK mutants are detected in brains of immunocompromised

Thymidine Kinase-Negative Herpes Simplex Virus 1 Can Efficiently Establish Persistent Infection in Neural Tissues of Nude Mice

PubMed Central

Huang, Chih-Yu; Yao, Hui-Wen; Wang, Li-Chiu; Shen, Fang-Hsiu

2016-01-01

ABSTRACT Herpes simplex virus 1 (HSV-1) establishes latency in neural tissues of immunocompetent mice but persists in both peripheral and neural tissues of lymphocyte-deficient mice. Thymidine kinase (TK) is believed to be essential for HSV-1 to persist in neural tissues of immunocompromised mice, because infectious virus of a mutant with defects in both TK and UL24 is detected only in peripheral tissues, but not in neural tissues, of severe combined immunodeficiency mice (T. Valyi-Nagy, R. M. Gesser, B. Raengsakulrach, S. L. Deshmane, B. P. Randazzo, A. J. Dillner, and N. W. Fraser, Virology 199:484–490, 1994, https://doi.org/10.1006/viro.1994.1150). Here we find infiltration of CD4 and CD8 T cells in peripheral and neural tissues of mice infected with a TK-negative mutant. We therefore investigated the significance of viral TK and host T cells for HSV-1 to persist in neural tissues using three genetically engineered mutants with defects in only TK or in both TK and UL24 and two strains of nude mice. Surprisingly, all three mutants establish persistent infection in up to 100% of brain stems and 93% of trigeminal ganglia of adult nude mice at 28 days postinfection, as measured by the recovery of infectious virus. Thus, in mouse neural tissues, host T cells block persistent HSV-1 infection, and viral TK is dispensable for the virus to establish persistent infection. Furthermore, we found 30- to 200-fold more virus in neural tissues than in the eye and detected glycoprotein C, a true late viral antigen, in brainstem neurons of nude mice persistently infected with the TK-negative mutant, suggesting that adult mouse neurons can support the replication of TK-negative HSV-1. IMPORTANCE Acyclovir is used to treat herpes simplex virus 1 (HSV-1)-infected immunocompromised patients, but treatment is hindered by the emergence of drug-resistant viruses, mostly those with mutations in viral thymidine kinase (TK), which activates acyclovir. TK mutants are detected in brains of

Preterm infant gut microbiota affects intestinal epithelial development in a humanized microbiome gnotobiotic mouse model.

PubMed

Yu, Yueyue; Lu, Lei; Sun, Jun; Petrof, Elaine O; Claud, Erika C

2016-09-01

Development of the infant small intestine is influenced by bacterial colonization. To promote establishment of optimal microbial communities in preterm infants, knowledge of the beneficial functions of the early gut microbiota on intestinal development is needed. The purpose of this study was to investigate the impact of early preterm infant microbiota on host gut development using a gnotobiotic mouse model. Histological assessment of intestinal development was performed. The differentiation of four epithelial cell lineages (enterocytes, goblet cells, Paneth cells, enteroendocrine cells) and tight junction (TJ) formation was examined. Using weight gain as a surrogate marker for health, we found that early microbiota from a preterm infant with normal weight gain (MPI-H) induced increased villus height and crypt depth, increased cell proliferation, increased numbers of goblet cells and Paneth cells, and enhanced TJs compared with the changes induced by early microbiota from a poor weight gain preterm infant (MPI-L). Laser capture microdissection (LCM) plus qRT-PCR further revealed, in MPI-H mice, a higher expression of stem cell marker Lgr5 and Paneth cell markers Lyz1 and Cryptdin5 in crypt populations, along with higher expression of the goblet cell and mature enterocyte marker Muc3 in villus populations. In contrast, MPI-L microbiota failed to induce the aforementioned changes and presented intestinal characteristics comparable to a germ-free host. Our data demonstrate that microbial communities have differential effects on intestinal development. Future studies to identify pioneer settlers in neonatal microbial communities necessary to induce maturation may provide new insights for preterm infant microbial ecosystem therapeutics. Copyright © 2016 the American Physiological Society.

Evolution of infection in mice inoculated by the oral route with different developmental forms of Trypanosoma cruzi I and II.

PubMed

Dias, Greicy Brisa Malaquias; Gruendling, Ana Paula; Araújo, Silvana Marques; Gomes, Mônica Lúcia; Toledo, Max Jean de Ornelas

2013-11-01

Oral infection has become the most important transmission mechanism of Chagas disease in Brazil. For this study, the development of Trypanosoma cruzi infection in mice, induced by the oral and intraperitoneal (IP) routes, was compared. Four groups of Swiss mice were used to evaluate the influence of parasite genetics, number of parasites, inoculation volume and developmental stages on the development of the orally induced infection: 1 - blood trypomastigotes (BT) via oral; 2 - BT via IP; 3 - culture metacyclic trypomastigotes (MT) via oral; and 4 - culture MT via IP. Animals inoculated orally showed levels of parasitemia, as well as infectivity and mortality rates, lower than animals inoculated via IP, regardless of DTU (discrete typing unit) and inoculum. Animals infected with TcII showed higher levels of these parameters than did animals infected with TcI. The larger volume of inoculum showed a greater capacity to cause an infection when administered via the oral route. BT infection was more virulent than culture MT infection for both routes (oral and IP). However, mice inoculated orally with BT showed lower levels than via IP, while mice inoculated orally with culture MT showed similar levels of infection to those inoculated via IP. Mice inoculated with culture MT showed more histopathological changes than those inoculated with BT, regardless of the inoculation route. These results indicate that this alternative experimental model is useful for evaluating infection by T. cruzi isolates with subpatent parasitemia and low virulence, such as those belonging to the TcI and TcIV DTUs, which are prevalent in outbreaks of orally transmitted Chagas disease. Copyright © 2013 Elsevier Inc. All rights reserved.

[Experimental model of activated Lamblia (Giardia) muris infection in albino mice].

PubMed

Irikov, O A; Kovalenko, F P

2007-01-01

Experimental L. muris infection was reproduced in 100% of the intact albino mice intragastrically given levomycin in an average total dose of 15.88-34.84 or 0.88-1.02 g/kg for 18-34 days. With levomycin administration, the intensity of giardiasis was 1121.6-8540.1 (mean 4830.9) thousand L. muris trophozoites per animal. The total number of trophozoites per animal decreased to 302.2-3481.4 (mean 1546.4) thousand and 28.1-324.0 (mean 109.4) thousand specimens 5-8 and 11-13 days after discontinuation of the antibiotic, respectively. The maximum number of L. muris trophozoites was observed in the proximal and middle portions of the murine small intestine during and after the administration oflevomycin. The highest isolation of cysts was seen 12-14 days after the initiation of administration of the antibiotic. Following 8-10 days of terminations of a course of levomycin therapy the native smear of animal feces showed no Lamblia cysts. In mice with activated infection, the isolation rate of Lamblia cysts was directly related to the intensity of intestinal infection with trophozoites of the parasite.

Altered Protein Expression in the Ileum of Mice Associated with the Development of Chronic Infections with Echinostoma caproni (Trematoda)

PubMed Central

Cortés, Alba; Sotillo, Javier; Muñoz-Antoli, Carla; Fried, Bernard; Esteban, J. Guillermo; Toledo, Rafael

2015-01-01

Background Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been extensively used as experimental model to investigate the factors determining the expulsion of intestinal helminths or, in contrast, the development of chronic infections. Herein, we analyze the changes in protein expression induced by E. caproni infection in ICR mice, a host of high compatibility in which the parasites develop chronic infections. Methodology/Principal Findings To determine the changes in protein expression, a two-dimensional DIGE approach using protein extracts from the intestine of naïve and infected mice was employed; and spots showing significant differential expression were analyzed by mass spectrometry. A total of 37 spots were identified differentially expressed in infected mice (10 were found to be over-expressed and 27 down-regulated). These proteins were related to the restoration of the intestinal epithelium and the control of homeostatic dysregulation, concomitantly with mitochondrial and cytoskeletal proteins among others. Conclusion/Significance Our results suggests that changes in these processes in the ileal epithelium of ICR mice may facilitate the establishment of the parasite and the development of chronic infections. These results may serve to explain the factors determining the development of chronicity in intestinal helminth infection. PMID:26390031

Depletion of Phagocytic Cells during Nonlethal Plasmodium yoelii Infection Causes Severe Malaria Characterized by Acute Renal Failure in Mice

PubMed Central

Terkawi, Mohamad Alaa; Nishimura, Maki; Furuoka, Hidefumi

2016-01-01

In the current study, we examined the effects of depletion of phagocytes on the progression of Plasmodium yoelii 17XNL infection in mice. Strikingly, the depletion of phagocytic cells, including macrophages, with clodronate in the acute phase of infection significantly reduced peripheral parasitemia but increased mortality. Moribund mice displayed severe pathological damage, including coagulative necrosis in liver and thrombi in the glomeruli, fibrin deposition, and tubular necrosis in kidney. The severity of infection was coincident with the increased sequestration of parasitized erythrocytes, the systematic upregulation of inflammation and coagulation, and the disruption of endothelial integrity in the liver and kidney. Aspirin was administered to the mice to minimize the risk of excessive activation of the coagulation response and fibrin deposition in the renal tissue. Interestingly, treatment with aspirin reduced the parasite burden and pathological lesions in the renal tissue and improved survival of phagocyte-depleted mice. Our data imply that the depletion of phagocytic cells, including macrophages, in the acute phase of infection increases the severity of malarial infection, typified by multiorgan failure and high mortality. PMID:26755155

The potential protective role of hepatitis B virus infection in pristane-induced lupus in mice.

PubMed

Liu, X; Jiao, Y; Cui, B; Gao, X; Xu, J; Zhao, Y

2016-10-01

The objective of this study was to investigate whether hepatitis B virus (HBV) infection plays a role in the regulation of autoimmunity for systemic lupus erythematosus (SLE). A total of 21 female BALB/c mice and 21 female HBV transgenic BALB/c mice aged two months were randomly divided into four groups: BALB/c mice, HBV(Tg) mice, pristane-injected BALB/c mice, and pristane-injected HBV(Tg) mice. BALB/c mice and HBV(Tg) mice were given an intraperitoneal injection of 0.5 ml normal saline, and the mice in the other two groups were given an intraperitoneal injection of 0.5 ml pristane. ANA and anti-dsDNA levels in serum were detected by indirect immunofluorescence. Interleukin 2 (IL-2), IL-4, IL-6, IL-17, and TNF-α were measured by Luminex technology. The serum BAFF level was measured using an Elisa kit. Twenty-four weeks after pristane administration, kidneys were removed, dissected, and stained with hematoxylin and eosin and periodic-acid Schiff. At six months after injecting, the ANA titers in pristane-injected HBV(Tg) mice were significantly lower than pristane-injected BALB/c mice. IL-17, TNF-α, and BAFF levels were significantly higher in pristane-injected BALB/c mice than BALB/c mice and pristane-injected HBV(Tg) mice. IL-2, IL-4, and IL-6 levels were much higher in pristane-injected HBV(Tg) mice than pristane-injected BALB/c mice. In pristane-injected HBV(Tg) mice and HBV(Tg) mice, fewer glomerulonephritis changes were found in the kidneys. Our results showed that the incidence of SLE was much lower in HBV(Tg) mice, and that HBV infection helped the SLE mice survive high levels of inflammatory cytokines and severe renal damage. All these findings demonstrated the protective role of HBV in SLE patients via the immunoregulatory networks of the cytokines. © The Author(s) 2016.

Host defense against systemic infection with Streptococcus pneumoniae is impaired in E-, P-, and E-/P-selectin-deficient mice.

PubMed Central

Munoz, F M; Hawkins, E P; Bullard, D C; Beaudet, A L; Kaplan, S L

1997-01-01

Endothelial selectins mediate rolling of leukocytes on endothelium, a crucial step for leukocyte firm adhesion and emigration into sites of tissue injury and infection. To characterize the role of the endothelial selectins during bacterial sepsis in vivo, Streptococcus pneumoniae (1-10 x 10(6) colony-forming units) was inoculated intraperitoneally into wild-type mice and mice with E-, P-, or E-/P-selectin deficiencies. Mice were followed 10 d for morbidity, survival, clearance of bacteremia, and leukocyte migration to the peritoneal cavity and organs 48 h after infection. All selectin-deficient mice showed a more pronounced morbidity, a significantly higher mortality associated with persistent bacteremia, and a higher bacterial load when compared with wild-type mice. These differences were most remarkable in the E-selectin-deficient mice, which showed the highest rate of mortality and bacteremia (P mice. Although the absence of endothelial selectins did not substantially impair leukocyte emigration to sites of infection 48 h after pneumococcal sepsis, it resulted in increased mortality and a higher bacterial load in the bloodstream of selectin-deficient mice. These results demonstrate a definitive phenotypic abnormality in E-selectin-deficient mice, and suggest that E- and P-selectin are important in the host defense against S. pneumoniae infection. PMID:9329976

Poliomyelitis in MuLV-infected ICR-SCID mice after injection of basement membrane matrix contaminated with lactate dehydrogenase-elevating virus.

PubMed

Carlson Scholz, Jodi A; Garg, Rohit; Compton, Susan R; Allore, Heather G; Zeiss, Caroline J; Uchio, Edward M

2011-10-01

The arterivirus lactate dehydrogenase-elevating virus (LDV) causes life-long viremia in mice. Although LDV infection generally does not cause disease, infected mice that are homozygous for the Fv1(n) allele are prone to develop poliomyelitis when immunosuppressed, a condition known as age-dependent poliomyelitis. The development of age-dependent poliomyelitis requires coinfection with endogenous murine leukemia virus. Even though LDV is a common contaminant of transplantable tumors, clinical signs of poliomyelitis after inadvertent exposure to LDV have not been described in recent literature. In addition, LDV-induced poliomyelitis has not been reported in SCID or ICR mice. Here we describe the occurrence of poliomyelitis in ICR-SCID mice resulting from injection of LDV-contaminated basement membrane matrix. After exposure to LDV, a subset of mice presented with clinical signs including paresis, which was associated with atrophy of the hindlimb musculature, and tachypnea; in addition, some mice died suddenly with or without premonitory signs. Mice presenting within the first 6 mo after infection had regions of spongiosis, neuronal necrosis and astrocytosis of the ventral spinal cord, and less commonly, brainstem. Axonal degeneration of ventral roots prevailed in more chronically infected mice. LDV was identified by RT-PCR in 12 of 15 mice with typical neuropathology; positive antiLDV immunolabeling was identified in all PCR-positive animals (n = 7) tested. Three of 8 mice with neuropathology but no clinical signs were LDV negative by RT-PCR. RT-PCR yielded murine leukemia virus in spinal cords of all mice tested, regardless of clinical presentation or neuropathology.

Protective effect of humus extract against Trypanosoma brucei infection in mice.

PubMed

Kodama, Hiroshi; Denso; Okazaki, Fumi; Ishida, Saeko

2008-11-01

Humic substances are formed during the decomposition of organic matter in humus, and are found in many natural environments in which organic materials and microorganisms are present. Oral administration of humus extract to mice successfully induced effective protection against experimental challenge by the two subspecies, Trypanosoma brucei brucei and T. brucei gambiense. Mortality was most reduced among mice who received a 3% humus extract for 21 days in drinking water ad libitum. Spleen cells from humus-administered mice exhibited significant non-specific cytotoxic activity against L1210 mouse leukemia target cells. Also, spleen cells produced significantly higher amounts of Interferon-gamma when stimulated in vitro with Concanavalin A than cells from normal controls. These results clearly show that administration to mice of humus extract induced effective resistance against Trypanosoma infection. Enhancement of the innate immune system may be involved in host defense against trypanosomiasis.

[Modeling of mixed infection by tick-borne encephalitis and Powassan viruses in mice].

PubMed

Khozinskaia, G A; Pogodina, V V

1982-01-01

Simultaneous inoculation of mice with tick-borne and Powassan viruses was shown, depending on experimental conditions, to result either in stimulation of infection or its unchanged course as compared with monoinfection and inoculation with the viruses at 2--3-week intervals in cross protection of mice against the superinfecting virus. Simultaneous inoculation of mice with the two viruses was accompanied by their multiplication in the blood and brains of mice and formation of antihemagglutinating antibodies to each of them. In the virus population in the brains of mice there was either formation of a mixture of two viruses or their phenotypic mixing. In cross protection, multiplication of the superinfecting virus in the blood and brain of mice was slightly inhibited, the antihemagglutinating antibody to a second virus either did not form or appeared in low titres.

Inhibitory Effect of Glutathione on Oxidative Liver Injury Induced by Dengue Virus Serotype 2 Infections in Mice

PubMed Central

Wang, Juan; Chen, Yanlei; Gao, Na; Wang, Yisong; Tian, Yanping; Wu, Jiangman; Zhang, Junlei; Zhu, Junping; Fan, Dongying; An, Jing

2013-01-01

The pathogenesis of dengue virus (DV) infection has not been completely defined and change of redox status mediated by depletion of glutathione (GSH) in host cell is a common result of viral infection. Our previous study has demonstrated that DV serotype 2 (DV2) infection alters host intracellular GSH levels, and exogenous GSH inhibits viral production by modulating the activity of NF-κB in HepG2 cells. GSH is the most powerful intracellular antioxidant and involved in viral infections. Thus, this study was to investigate whether DV2 infection can induce alteration in redox balance and effect of GSH on the disease in HepG2 xenografts SCID mice. Our results revealed that mice infected with DV2 showed alterations in oxidative stress by increasing the level of malondialdehyde (MDA), an end product of lipid peroxidation, and GSSG/GSH ratio. DV2-infected mice also showed a decrease in the activity of catalase (CAT) and total superoxide dismutase (T-SOD) in the serum and/or observed organs, especially the liver. Moreover, DV2 infection resulted in elevated serum levels of the cytokines tumor necrosis factor-α and interlukin-6 and obvious histopathological changes in the liver. The administration of exogenous GSH significantly reversed all of the aforementioned pathological changes and prevented significant liver damage. Furthermore, in vitro treatment of HepG2 cells with antioxidants such as GSH inhibited viral entry as well as the production of reactive oxygen species in HepG2 cells. These results suggest that GSH prevents DV2-induced oxidative stress and liver injury in mice by inhibiting proinflammatory cytokine production, and GSH and may be a promising therapeutic agent for prevention of oxidative liver damage during DV infection. PMID:23383181

Infection Susceptibility in Gastric Intrinsic Factor (Vitamin B12)-Defective Mice Is Subject to Maternal Influences

PubMed Central

Mottram, Lynda; Speak, Anneliese O.; Selek, Reza M.; Cambridge, Emma L.; McIntyre, Zoe; Kane, Leanne; Mukhopadhyay, Subhankar; Grove, Carolyn; Colin, Amy; Brandt, Cordelia; Duque-Correa, Maria A.; Forbester, Jessica; Nguyen, Tu Anh Pham; Hale, Christine; Vasilliou, George S.; Arends, Mark J.; Wren, Brendan W.; Dougan, Gordon

2016-01-01

ABSTRACT Mice harboring a mutation in the gene encoding gastric intrinsic factor (Gif), a protein essential for the absorption of vitamin B12/cobalamin (Cbl), have potential as a model to explore the role of vitamins in infection. The levels of Cbl in the blood of Giftm1a/tm1a mutant mice were influenced by the maternal genotype, with offspring born to heterozygous (high Cbl, F1) mothers exhibiting a significantly higher serum Cbl level than those born to homozygous (low Cbl, F2) equivalents. Low Cbl levels correlated with susceptibility to an infectious challenge with Salmonella enterica serovar Typhimurium or Citrobacter rodentium, and this susceptibility phenotype was moderated by Cbl administration. Transcriptional and metabolic profiling revealed that Cbl deficient mice exhibited a bioenergetic shift similar to a metabolic phenomenon commonly found in cancerous cells under hypoxic conditions known as the Warburg effect, with this metabolic effect being exacerbated further by infection. Our findings demonstrate a role for Cbl in bacterial infection, with potential general relevance to dietary deficiency and infection susceptibility. PMID:27329747

Spontaneous bacterial and fungal infections in genetically engineered mice: Is Escherichia coli an emerging pathogen in laboratory mouse?

PubMed

Benga, Laurentiu; Benten, W Peter M; Engelhardt, Eva; Gougoula, Christina; Sager, Martin

2015-01-01

The impact of particular microbes on genetically engineered mice depends on the genotype and the environment. Infections resulting in clinical disease have an obvious impact on animal welfare and experimentation. In this study, we investigated the bacterial and fungal aetiology of spontaneous clinical disease of infectious origin among the genetically engineered mice from our institution in relation to their genotype. A total of 63 mice belonging to 33 different mice strains, from severe immunodeficient to wild-type, were found to display infections as the primary cause leading to their euthanasia. The necropsies revealed abscesses localized subcutaneously as well as in the kidney, preputial glands, seminal vesicles, in the uterus, umbilicus or in the lung. In addition, pneumonia, endometritis and septicaemia cases were recorded. Escherichia coli was involved in 21 of 44 (47.72%) of the lesions of bacterial origin, whereas [Pasteurella] pneumotropica was isolated from 19 of 44 (43.18%) cases. The infections with the two agents mentioned above included three cases of mixed infection with both pathogens. Staphylococcus aureus was considered responsible for five of 44 (11.36%) cases whereas Enterobacter cloacae was found to cause lesions in two of 44 (4.54%) mice. Overall, 16 of the 44 (36.36%) cases of bacterial aetiology affected genetically engineered mice without any explicit immunodeficiency or wild-type strains. The remaining 19 cases of interstitial pneumonia were caused by Pneumocystis murina. In conclusion, the susceptibility of genetically modified mice to opportunistic infections has to be regarded with precaution, regardless of the type of genetic modification performed. Beside the classical opportunists, such as [Pasteurella] pneumotropica and Staphylococcus aureus, Escherichia coli should as well be closely monitored to evaluate whether it represents an emerging pathogen in the laboratory mouse.

Induction of TNF-alfa and CXCL-2 mRNAs in different organs of mice infected with pathogenic Leptospira.

PubMed

da Silva, Josefa B; Carvalho, Enéas; Covarrubias, Ambart E; Ching, Ana Tung C; Mattaraia, Vania G M; Paiva, Delhi; de Franco, Marcelo; Fávaro, Regiane Degan; Pereira, Martha M; Vasconcellos, Silvio; Zorn, Telma T M; Ho, Paulo Lee; Martins, Elizabeth A L

2012-04-01

The role of innate immune response in protection against leptospirosis is poorly understood. We examined the expression of the chemokine CXCL2/MIP-2 and the cytokine TNF-α in experimental resistant and susceptible mice models, C3H/HeJ, C3H/HePas and BALB/c strains, using a virulent strain of Leptospira interrogans serovar Copenhageni. Animals were infected intraperitoneally with 10(7) cells and the development of the disease was followed. Mortality of C3H/HeJ mice was observed whereas C3H/HePas presented jaundice and BALB/c mice remained asymptomatic. The infection was confirmed by the presence of leptospiral DNA in the organs of the animals, demonstrated by PCR. Sections of the organs were analyzed, after H&E stain. The relative expression of mRNA of chemokine CXCL2/MIP-2 and cytokine TNF-α was measured in lung, kidney and liver of the mice by qPCR. The concentrations of these proteins were measured in extracts of tissues and in serum of the animals, by ELISA. Increasing levels of transcripts and protein CXCL2/MIP-2 were detected since the first day of infection. The highest expression was observed at third day of infection in kidney, liver and lung of BALB/c mice. In C3H/HeJ the expression of CXCL2/MIP-2 was delayed, showing highest protein concentration in lung and kidney at the 5th day. Increasing in TNF-α transcripts were detected after infection, in kidney and liver of animals from the three mice strains. The expression of TNF-α protein in C3H/HeJ was also delayed, being detected in kidney and lung. Our data demonstrated that Leptospira infection stimulates early expression of CXCL2/MIP-2 and TNF-α in the resistant strain of mice. Histological analysis suggests that the expression of those molecules may be related to the influx of distinct immune cells and plays a role in the naturally acquired protective immunity. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Efficacy of albendazole chitosan microspheres against Echinococcus granulosus infection in mice].

PubMed

Liang, Wen; Wang, Xin-Chun; Wu, Xiang-Wei; Zhang, Shi-Jie; Sun, Hong; Ma, Xin; Peng, Xin-Yu

2014-06-01

To observe the therapeutic effect of albendazole chitosan microspheres (ABZ-CS-MPs) on cystic echinococcosis in mice. Two hundred male kunming mice were each infected by intraperitoneal inoculation of about 5 000 viable protoscoleces of Echinococcus granulosus. Another 20 mice were kept as blank control. After 12 weeks post infection, the mice were randomly divided into four groups named as infection control group (n = 20), ABZ-CS-MPs group, albendazole liposome (L-ABZ) group, and albendazole tablet group. The latter three treatment groups were then each divided into three subgroups (n = 20) by given the dose of 37.5, 75.0, and 150.0 mg/kg for three times per week, respectively. After 12 weeks of treatment, all mice were sacrificed. The weight of hydatid cysts was measured and the inhibition rate were calculated. Mouse liver was observed. The histopathological changes of E. granulosus were observed by microscopy. The concentration of albendazole sulfoxide in plasma and liver tissues was determined by high-performance liquid chromatography. Compared with the other treatment groups, the turbidity of contained fluid, the consolidation level and calcification level of hydatid cysts in ABZ-CS-MPs group were higher. The average weight of hydatid cysts in each treatment group was lower than that of infection control group [(3.19 +/- 2.94) g] (P < 0.05). The cyst weight in 37.5, 75.0, and 150.0 mg/kg ABZ-CS-MPs group [(0.28 +/- 0.28), (0.24 +/- 0.22), and (0.20 +/- 0.19) g, respectively] was lower than that of albendazole tablet groups [(0.77 +/- 0.74), (0.55 +/- 0.42), (0.76 +/- 0.35) g] (P < 0.05). Among the same dosage groups, the inhibition rate in ABZ-CS-MPs group (from low to high dosage sub-group: 91.1%, 92.6%, and 93.7%, respectively) was highest. In 75.0 mg/kg ABZ-CS-MPs group, there were 15 mice with class I (degeneration) and II (necrosis) pathological changes of E. granulosus hydatid. The number of mice with class I and II pathological changes in each dosage

Concomitant Benznidazole and Suramin Chemotherapy in Mice Infected with a Virulent Strain of Trypanosoma cruzi

PubMed Central

Santos, Eliziária C.; Cupertino, Marli C.; Bastos, Daniel S. S.; Klein, Raphael C.; Silva, Eduardo A. M.; Fietto, Juliana L. R.; Talvani, André; Bahia, Maria T.

2015-01-01

Although suramin (Sur) is suggested as a potential drug candidate in the management of Chagas disease, this issue has not been objectively tested. In this study, we examined the applicability of concomitant treatment with benznidazole (Bz) and suramin in mice infected with a virulent strain of Trypanosoma cruzi. Eighty 12-week-old male C57BL/6 mice were equally randomized in eight groups: (i) noninfected mice (negative control) and mice infected with T. cruzi Y strain receiving (ii) no treatment (positive control), (iii) Bz, 100 mg/kg of body weight per day, (iv) Sur, 20 mg/kg/day, and (v to viii) Sur, 20 mg/kg/day, combined with Bz, 100, 50, 25, or 5 mg/kg/day. Bz was administered by gavage, and Sur was administered intraperitoneally. Sur dramatically increased the parasitemia, cardiac content of parasite DNA, inflammation, oxidative tissue damage, and mortality. In response to high parasitic load in cardiac tissue, Sur stimulated the immune system in a manner typical of the acute phase of Chagas disease, increasing tissue levels of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) and inducing a preferential IgG2a anti-T. cruzi serum pattern. When Sur and Bz were combined, the infection severity was attenuated, showing a dose-dependent Bz response. Sur therapy had a more harmful effect on the host than on the parasite and reduced the efficacy of Bz against T. cruzi infection. Considering that Sur drastically reinforced the infection evolution, potentiating the inflammatory process and the severity of cardiac lesions, the in vivo findings contradicted the in vitro anti-T. cruzi potential described for this drug. PMID:26169419

Taenia crassiceps: infections of male mice lead to severe disruption of seminiferous tubule cells and increased apoptosis.

PubMed

Zepeda, Nadia; Copitin, Natalia; Solano, Sandra; González, Maricarmen; Fernández, Ana M; Tato, Patricia; Molinari, José L

2011-01-01

This research was carried out to study the effects of infection with Taenia crassiceps cysticerci on the seminiferous epithelium histoarchitecture in the testes of male mice. Our results showed a severe disruption of the histoarchitecture of the testis epithelium in infected mice. In these animals, a significant infiltration of macrophages within seminiferous tubules was observed (P < 0.001). Generalized apoptosis of germ cells within the seminiferous tubules was observed, as assessed by TUNEL assay and apoptotic nuclei were quantified. The total number of fluorescent objects (DNA) (including clusters, singles, and objects in clusters) was significantly higher in the infected cells than in the control group (P = 0.0286). Observation of the interstitial tissue showed disorder and deterioration of many Leydig cells of infected mice, as well as intense vacuolization and destruction of their inter-cellular junctions. Several ultrastructural abnormalities were observed through electron microscopy as well. The observed pathology could lead to a state of infertility. Copyright © 2010 Elsevier Inc. All rights reserved.

Antiplasmodial activity of Xanthium strumarium against Plasmodium berghei-infected BALB/c mice.

PubMed

Chandel, Sanjeev; Bagai, Upma; Vashishat, Nisha

2012-03-01

The present work was undertaken to evaluate the antiplasmodial activity of ethanolic leaves extract of traditional medicinal plant Xanthium strumarium in Plasmodium berghei-infected BALB/c mice along with phytochemical screening and acute toxicity test to support its traditional medicinal use as a malaria remedy. The ethanolic leaves extract of X. strumarium (ELEXS) 150, 250, 350 and 500 mg/kg/day demonstrated dose-dependent chemosuppression during early and established infection long with significant (p < 0.001) repository activity. The oral administration of 500 mg/kg/day concentration showed a maximum of 88.6% chemosuppression during early infection, which was more than that of the standard drug chloroquine (5 mg/kg/day) with 88.3% chemosuppression. However, 60% mortality has been found in this group. The LD(50) of ELEXS was found to be 1.5 g/kg/mouse. The administration of 350 mg/kg/day concentration of extract have been found to exert 90.40% chemosuppression during repository infection, which was well comparable to standard drug pyrimethamine (1.2 mg/kg/day) exerting 92.91% chemosuppression. The extract has been found to enhance mean survival time of mice from 21 to 26 days with 250 and 350 mg/kg/day concentrations, while 150 mg/kg/day concentration has been found to sustain all the mice up to 29 days which was similar to the employed standard drug chloroquine (5 mg/kg/day). All these findings support the ethanopharmacological use of X. strumarium as malarial remedy and indicate the potential of plant for active antiplasmodial components.

Neutrophil Depletion Suppresses Pulmonary Vascular Hyperpermeability and Occurrence of Pulmonary Edema Caused by Hantavirus Infection in C.B-17 SCID Mice

PubMed Central

Koma, Takaaki; Yoshimatsu, Kumiko; Nagata, Noriyo; Sato, Yuko; Shimizu, Kenta; Yasuda, Shumpei P.; Amada, Takako; Nishio, Sanae; Hasegawa, Hideki

2014-01-01

ABSTRACT Hantavirus infections are characterized by vascular hyperpermeability and neutrophilia. However, the pathogenesis of this disease is poorly understood. Here, we demonstrate for the first time that pulmonary vascular permeability is increased by Hantaan virus infection and results in the development of pulmonary edema in C.B-17 severe combined immunodeficiency (SCID) mice lacking functional T cells and B cells. Increases in neutrophils in the lung and blood were observed when pulmonary edema began to be observed in the infected SCID mice. The occurrence of pulmonary edema was inhibited by neutrophil depletion. Moreover, the pulmonary vascular permeability was also significantly suppressed by neutrophil depletion in the infected mice. Taken together, the results suggest that neutrophils play an important role in pulmonary vascular hyperpermeability and the occurrence of pulmonary edema after hantavirus infection in SCID mice. IMPORTANCE Although hantavirus infections are characterized by the occurrence of pulmonary edema, the pathogenic mechanism remains largely unknown. In this study, we demonstrated for the first time in vivo that hantavirus infection increases pulmonary vascular permeability and results in the development of pulmonary edema in SCID mice. This novel mouse model for human hantavirus infection will be a valuable tool and will contribute to elucidation of the pathogenetic mechanisms. Although the involvement of neutrophils in the pathogenesis of hantavirus infection has largely been ignored, the results of this study using the mouse model suggest that neutrophils are involved in the vascular hyperpermeability and development of pulmonary edema in hantavirus infection. Further study of the mechanisms could lead to the development of specific treatment for hantavirus infection. PMID:24719427

Dengue virus infection induces broadly cross-reactive human IgM antibodies that recognize intact virions in humanized BLT-NSG mice

PubMed Central

Jaiswal, Smita; Smith, Kenneth; Ramirez, Alejandro; Woda, Marcia; Pazoles, Pamela; Shultz, Leonard D; Greiner, Dale L; Brehm, Michael A

2015-01-01

The development of small animal models that elicit human immune responses to dengue virus (DENV) is important since prior immunity is a major risk factor for developing severe dengue disease. This study evaluated anti-DENV human antibody (hAb) responses generated from immortalized B cells after DENV-2 infection in NOD-scid IL2rγnull mice that were co-transplanted with human fetal thymus and liver tissues (BLT-NSG mice). DENV-specific human antibodies predominantly of the IgM isotype were isolated during acute infection and in convalescence. We found that while a few hAbs recognized the envelope protein produced as a soluble recombinant, a number of hAbs only recognized epitopes on intact virions. The majority of the hAbs isolated during acute infection and in immune mice were serotype-cross-reactive and poorly neutralizing. Viral titers in immune BLT-NSG mice were significantly decreased after challenge with a clinical strain of dengue. DENV-specific hAbs generated in BLT-NSG mice share some of the characteristics of Abs isolated in humans with natural infection. Humanized BLT-NSG mice provide an attractive preclinical platform to assess the immunogenicity of candidate dengue vaccines. PMID:25125497

HIV-1 vaccine-specific responses induced by Listeria vector vaccines are maintained in mice subsequently infected with a model helminth parasite, Schistosoma mansoni.

PubMed

Shollenberger, Lisa M; Bui, Cac T; Paterson, Yvonne; Nyhoff, Lindsay; Harn, Donald A

2013-11-19

In areas co-endemic for helminth parasites and HIV/AIDS, infants are often administered vaccines prior to infection with immune modulatory helminth parasites. Systemic Th2 biasing and immune suppression caused by helminth infection reduces cell-mediated responses to vaccines such as tetanus toxoid and BCG. Therefore, we asked if infection with helminthes post-vaccination, alters already established vaccine induced immune responses. In our model, mice are vaccinated against HIV-1 Gag using a Listeria vaccine vector (Lm-Gag) in a prime-boost manner, then infected with the human helminth parasite Schistosoma mansoni. This allows us to determine if established vaccine responses are maintained or altered after helminth infection. Our second objective asked if helminth infection post-vaccination alters the recipient's ability to respond to a second boost. Here we compared responses between uninfected mice, schistosome infected mice, and infected mice that were given an anthelminthic, which occurred coincident with the boost or four weeks prior, as well as comparing to un-boosted mice. We report that HIV-1 vaccine-specific responses generated by Listeria vector HIV-1 vaccines are maintained following subsequent chronic schistosome infection, providing further evidence that Listeria vector vaccines induce potent vaccine-specific responses that can withstand helminth infection. We also were able to demonstrate that administration of a second Listeria boost, which markedly enhanced the immune response, was minimally impacted by schistosome infection, or anthelminthic therapy. Surprisingly, we also observed enhanced antibody responses to HIV Gag in vaccinated mice subsequently infected with schistosomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Polysaccharides from the Chinese medicinal herb Achyranthes bidentata enhance anti-malarial immunity during Plasmodium yoelii 17XL infection in mice.

PubMed

Zhu, Xiaotong; Pan, Yanyan; Zheng, Li; Cui, Liwang; Cao, Yaming

2012-02-20

Clinical immunity to malaria in human populations is developed after repeated exposure to malaria. Regulation and balance of host immune responses may lead to optimal immunity against malaria parasite infection. Polysaccharides (ABPS) derived from the Chinese herb ox knee Achyranthes bidentata possess immuno-modulatory functions. The aim of this study is to use the rodent malaria model Plasmodium yoelii 17XL (P. y17XL) to examine whether pretreatment with ABPS will modulate host immunity against malaria infection and improve the outcome of the disease. To determine whether ABPS could modulate immunity against malaria, mice were pretreated with ABPS prior to blood-stage infection by P. y17XL. Host survival and parasitaemia were monitored daily. The effect of pretreatment on host immune responses was studied through the quantitation of cytokines, dendritic cell populations, and natural regulatory T cells (Treg). Pretreatment with ABPS prior to infection significantly extended the survival time of mice after P. y17XL infection. At three and five days post-infection, ABPS pretreated mice developed stronger Th1 immune responses against malaria infection with the number of F4/80+CD36+ macrophages and levels of IFN-γ, TNF-α and nitric oxide being significantly higher than in the control group. More importantly, ABPS-treated mice developed more myeloid (CD11c+CD11b+) and plasmacytoid dendritic cells (CD11c+CD45R+/B220+) than control mice. ABPS pretreatment also resulted in modulated expression of MHC-II, CD86, and especially Toll-like receptor 9 by CD11c+ dendritic cells. In comparison, pretreatment with ABPS did not alter the number of natural Treg or the production of the anti-inflammatory cytokine IL-10. Pretreatment with the immuno-modulatory ABPS selectively enhanced Th1 immune responses to control the proliferation of malaria parasites, and prolonged the survival of mice during subsequent malaria infection.

Experimental infection with Cryptosporidium parvum IIaA21G1R1 subtype in immunosuppressed mice

USDA-ARS?s Scientific Manuscript database

Cryptosporidium parvum subtype IIaA21G1R1 oocysts were used to infect dexamethasone immunosuppressed N: NIH Swiss mice. Histology showed developmental stages in the duodenum, proximal and distal jejunum, ileum, cecum and colon, with the small intestine remaining infected until day 35 post infection....

Plasmodium berghei: infectivity of mice to Anopheles stephensi mosquitoes.

PubMed

Butcher, G A; Sinden, R E; Billker, O

1996-12-01

The infectivity of P. berghei-infected TO mice to mosquitoes declines rapidly 2 to 5 days after blood inoculation, in spite of rising numbers of gametocytes in the blood. This pattern is typical of many malaria infections and various factors, particularly specific and nonspecific immune responses, have previously been implicated in the decline. Here we report that (1) simple physiological changes in the mouse blood, namely, falling pH and bicarbonate levels induced by high parasitaemias, are responsible for the sustained inhibition of infectivity; (2) the inhibition is reversible in vivo by the addition of sodium bicarbonate alone; (3) the inhibition occurs at the point of exflagellation; (4) contrary to previous observations (Kawamoto et al. 1992), exflagellation in P. berghei, like that in P. gallinaceum (Bishop and McConnachie 1956; Nijhout and Carter 1978; Nijhout 1979) and P. falciparum (Ogwan'g et al. 1993), is dependent on extracellular bicarbonate; and (5) induction of exflagellation by a mosquito factor is bicarbonate dependent. These new observations are critical to the design and interpretation of experiments on other transmission blocking phenomena.

Toxoplasma gondii infection blocks the development of allergic airway inflammation in BALB/c mice.

PubMed

Fenoy, I; Giovannoni, M; Batalla, E; Martin, V; Frank, F M; Piazzon, I; Goldman, A

2009-02-01

There is a link between increased allergy and a reduction of some infections in western countries. Epidemiological data also show that respiratory allergy is less frequent in people exposed to orofaecal and foodborne microbes such as Toxoplasma gondii. Infection with T. gondii induces a strong cell-mediated immunity with a highly polarized T helper type 1 (Th1) response in early stages of infection. Using a well-known murine model of allergic lung inflammation, we sought to investigate whether T. gondii infection could modulate the susceptibility to develop respiratory allergies. Both acute and chronic infection with T. gondii before allergic sensitization resulted in a diminished allergic inflammation, as shown by a decrease in bronchoalveolar lavage (BAL) eosinophilia, mononuclear and eosinophil cell infiltration around airways and vessels and goblet cell hyperplasia. Low allergen-specific immunoglobulin (Ig)E and IgG1 and high levels of allergen-specific IgG2a serum antibodies were detected. A decreased interleukin (IL)-4 and IL-5 production by lymph node cells was observed, while no antigen-specific interferon-gamma increase was detected. Higher levels of the regulatory cytokine IL-10 were found in BAL from infected mice. These results show that both acute and chronic parasite infection substantially blocked development of airway inflammation in adult BALB/c mice. Our results support the hypothesis that T. gondii infection contributes to protection against allergy in humans.

Virological and clinico-pathological features of orf virus infection in experimentally infected rabbits and mice.

PubMed

Cargnelutti, J F; Masuda, E K; Martins, M; Diel, D G; Rock, D L; Weiblen, R; Flores, E F

2011-01-01

Many aspects of the biology of orf virus (ORFV) infection remain poorly understood and attempts to establish animal models have yielded conflicting and non-reproducible results. We herein describe the characterization of ORFV infection and disease in rabbits and mice. A protocol of intradermal inoculation was employed to inoculate 10(8.5)TCID₅₀/mL of ORFV strain IA-82 in the skin of ears, of the back and labial commissures. All inoculated rabbits presented a clinical course characterized by erythema, macules, papules/vesicles or pustules that eventually dried originating scabs. Local signs started around days 3 and 4 post-inoculation (pi) and lasted 3-10 days. Virus was recovered from lesions between days 2 and 14pi. Histological examination of lesions revealed focal proliferative dermatitis with ballooning degeneration and eosinophilic intracytoplasmic inclusion bodies in keratinocytes, histological hallmarks of contagious ecthyma in sheep. A similar, albeit milder clinical course occurred in 5/10 inoculated mice; virus was recovered from lesions from three animals. Inoculated lambs - used as controls - developed severe lesions of contagious ecthyma. VN tests performed at day 28pi failed to detect neutralizing antibodies in all inoculated animals. In contrast, convalescent rabbit sera were positive by ELISA at dilutions from 100 to 400. These results show that rabbits are susceptible to ORFV infection and thus may be used to study selected aspects of ORFV biology. Copyright © 2010 Elsevier Ltd. All rights reserved.

Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice

PubMed Central

van den Berg, Sanne; de Vogel, Corné P.; van Belkum, Alex; Bakker-Woudenberg, Irma A. J. M.

2015-01-01

Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P) or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG) levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect. PMID:26060995

Differential myelopoietic responsiveness of BALB/c (Itys) and C.D2 (Ityr) mice to lipopolysaccharide administration and Salmonella typhimurium infection.

PubMed

Peterson, V M; Madonna, G S; Vogel, S N

1992-04-01

Inheritance of the Ityr or the Itys allele of the Ity murine gene confers resistance or increased susceptibility, respectively, to Salmonella typhimurium infection. Recent studies have documented that Ity gene expression may determine net intracellular replication of S. typhimurium by modulating macrophage function. The purpose of this study was to determine if Ity gene expression modulated macrophage stem cell proliferation as well. To detect possible Ity-associated alterations in macrophage stem cell proliferation during endotoxin challenge or S. typhimurium infection, the congenic strain pair BALB/c (Itys) and C.D2-Idh-1, Pep-3 N20F8 (Ityr) were injected intraperitoneally with 25 micrograms of bacterial lipopolysaccharide (LPS) or approximately 10(3) S. typhimurium, and myelopoiesis was evaluated. At 72 h after LPS injection, both BALB/c and C.D2 mice developed comparable degrees of bone marrow hypocellularity and splenomegaly, and cell sizing profiles indicated a normal response to a single injection of LPS in both strains of mice. Although an inhibitor to colony-stimulating factor activity was detected in the sera and plasma of C.D2 mice, the number of myeloid stem cells cultured from the bone marrow and spleen of each mouse strain were comparable. S. typhimurium infection resulted in earlier symptoms, a larger bacterial load, a higher mortality rate, and a greater bone marrow hypocellularity and splenomegaly in BALB/c mice compared with those in C.D2 mice. Despite a dramatic increase in bacterial load, a decrease in both bone marrow and splenic myeloid stem cell numbers was noted in BALB/c mice, while stem cell numbers remained constant in C.D2 mice between days 3 and 5 and increased dramatically at day 7 after infection. These data suggest that BALB/c and C.D2 mice may exhibit a divergent myelopoietic response to S. typhimurium infection. It appears that a paradoxical failure of myelopoiesis in Itys mice during S. typhimurium infection may contribute to the

Differential myelopoietic responsiveness of BALB/c (Itys) and C.D2 (Ityr) mice to lipopolysaccharide administration and Salmonella typhimurium infection.

PubMed Central

Peterson, V M; Madonna, G S; Vogel, S N

1992-01-01

Inheritance of the Ityr or the Itys allele of the Ity murine gene confers resistance or increased susceptibility, respectively, to Salmonella typhimurium infection. Recent studies have documented that Ity gene expression may determine net intracellular replication of S. typhimurium by modulating macrophage function. The purpose of this study was to determine if Ity gene expression modulated macrophage stem cell proliferation as well. To detect possible Ity-associated alterations in macrophage stem cell proliferation during endotoxin challenge or S. typhimurium infection, the congenic strain pair BALB/c (Itys) and C.D2-Idh-1, Pep-3 N20F8 (Ityr) were injected intraperitoneally with 25 micrograms of bacterial lipopolysaccharide (LPS) or approximately 10(3) S. typhimurium, and myelopoiesis was evaluated. At 72 h after LPS injection, both BALB/c and C.D2 mice developed comparable degrees of bone marrow hypocellularity and splenomegaly, and cell sizing profiles indicated a normal response to a single injection of LPS in both strains of mice. Although an inhibitor to colony-stimulating factor activity was detected in the sera and plasma of C.D2 mice, the number of myeloid stem cells cultured from the bone marrow and spleen of each mouse strain were comparable. S. typhimurium infection resulted in earlier symptoms, a larger bacterial load, a higher mortality rate, and a greater bone marrow hypocellularity and splenomegaly in BALB/c mice compared with those in C.D2 mice. Despite a dramatic increase in bacterial load, a decrease in both bone marrow and splenic myeloid stem cell numbers was noted in BALB/c mice, while stem cell numbers remained constant in C.D2 mice between days 3 and 5 and increased dramatically at day 7 after infection. These data suggest that BALB/c and C.D2 mice may exhibit a divergent myelopoietic response to S. typhimurium infection. It appears that a paradoxical failure of myelopoiesis in Itys mice during S. typhimurium infection may contribute to the

Virulence, pathology, and pathogenesis of Pteropine orthoreovirus (PRV) in BALB/c mice: Development of an animal infection model for PRV.

PubMed

Egawa, Kazutaka; Shimojima, Masayuki; Taniguchi, Satoshi; Nagata, Noriyo; Tani, Hideki; Yoshikawa, Tomoki; Kurosu, Takeshi; Watanabe, Shumpei; Fukushi, Shuetsu; Saijo, Masayuki