CD8+ T Cell Exhaustion, Suppressed Gamma Interferon Production, and Delayed Memory Response Induced by Chronic Brucella melitensis Infection

PubMed Central

Durward-Diioia, Marina; Harms, Jerome; Khan, Mike; Hall, Cherisse; Smith, Judith A.

2015-01-01

Brucella melitensis is a well-adapted zoonotic pathogen considered a scourge of mankind since recorded history. In some cases, initial infection leads to chronic and reactivating brucellosis, incurring significant morbidity and economic loss. The mechanism by which B. melitensis subverts adaptive immunological memory is poorly understood. Previous work has shown that Brucella-specific CD8+ T cells express gamma interferon (IFN-γ) and can transition to long-lived memory cells but are not polyfunctional. In this study, chronic infection of mice with B. melitensis led to CD8+ T cell exhaustion, manifested by programmed cell death 1 (PD-1) and lymphocyte activation gene 3 (LAG-3) expression and a lack of IFN-γ production. The B. melitensis-specific CD8+ T cells that produced IFN-γ expressed less IFN-γ per cell than did CD8+ cells from uninfected mice. Both memory precursor (CD8+ LFA1HI CD127HI KLRG1LO) and long-lived memory (CD8+ CD27HI CD127HI KLRG1LO) cells were identified during chronic infection. Interestingly, after adoptive transfer, mice receiving cells from chronically infected animals were able to contain infection more rapidly than recipients of cells from acutely infected or uninfected donors, although the proportions of exhausted CD8+ T cells increased after adoptive transfer in both challenged and unchallenged recipients. CD8+ T cells of challenged recipients initially retained the stunted IFN-γ production found prior to transfer, and cells from acutely infected mice were never seen to transition to either memory subset at all time points tested, up to 30 days post-primary infection, suggesting a delay in the generation of memory. Here we have identified defects in Brucella-responsive CD8+ T cells that allow chronic persistence of infection. PMID:26416901

Towards an HIV cure based on targeted killing of infected cells: different approaches against acute versus chronic infection.

PubMed

Dey, Barna; Berger, Edward A

2015-05-01

Current regimens of combination antiretroviral therapy (cART) offer effective control of HIV infection, with maintenance of immune health and near-normal life expectancy. What will it take to progress beyond the status quo, whereby infectious virus can be eradicated (a 'sterilizing cure') or fully controlled without the need for ongoing cART (a 'functional cure')? On the basis of therapeutic advances in the cancer field, we propose that targeted cytotoxic therapy to kill HIV-infected cells represents a logical complement to cART for achieving an HIV cure. This concept is based on the fact that cART effectively blocks replication of the virus, but does not eliminate cells that are already infected; targeted cytotoxic therapy would contribute precisely this missing component. We suggest that different modalities are suited for curing primary acute versus established chronic infection. For acute infection, relatively short-acting potent agents such as recombinant immunotoxins might prove sufficient for HIV eradication, whereas for chronic infection, a long-lasting (lifelong?) modality is required to maintain full virus control, as might be achieved with genetically modified autologous T cells. We present perspectives for complementing cART with targeted cytotoxic therapy, whereby HIV infection is either eradicated or fully controlled, thereby eliminating the need for lifelong cART.

Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells.

PubMed Central

Harakeh, S; Jariwalla, R J; Pauling, L

1990-01-01

We have studied the action of ascorbate (vitamin C) on human immunodeficiency virus type 1 (HIV-1), the etiological agent clinically associated with AIDS. We report the suppression of virus production and cell fusion in HIV-infected T-lymphocytic cell lines grown in the presence of nontoxic concentrations of ascorbate. In chronically infected cells expressing HIV at peak levels, ascorbate reduced the levels of extracellular reverse transcriptase (RT) activity (by greater than 99%) and of p24 antigen (by 90%) in the culture supernatant. Under similar conditions, no detectable inhibitory effects on cell viability, host metabolic activity, and protein synthesis were observed. In freshly infected CD4+ cells, ascorbate inhibited the formation of giant-cell syncytia (by approximately 93%). Exposure of cell-free virus to ascorbate at 37 degrees C for 1 day had no effect on its RT activity or syncytium-forming ability. Prolonged exposure of virus (37 degrees C for 4 days) in the presence of ascorbate (100-150 micrograms/ml) resulted in the drop by a factor of 3-14 in RT activity as compared to a reduction by a factor of 25-172 in extracellular RT released from chronically infected cells. These results indicate that ascorbate mediates an anti-HIV effect by diminishing viral protein production in infected cells and RT stability in extracellular virions. Images PMID:1698293

Pig model mimicking chronic hepatitis E virus infection in immunocompromised patients to assess immune correlates during chronicity

PubMed Central

Cao, Dianjun; Cao, Qian M.; Subramaniam, Sakthivel; Yugo, Danielle M.; Heffron, C. Lynn; Rogers, Adam J.; Kenney, Scott P.; Tian, Debin; Matzinger, Shannon R.; Overend, Christopher; Catanzaro, Nicholas; LeRoith, Tanya; Wang, Heng; Piñeyro, Pablo; Lindstrom, Nicole; Clark-Deener, Sherrie; Yuan, Lijuan; Meng, Xiang-Jin

2017-01-01

Chronic hepatitis E virus (HEV) infection is a significant clinical problem in immunocompromised individuals such as organ transplant recipients, although the mechanism remains unknown because of the lack of an animal model. We successfully developed a pig model of chronic HEV infection and examined immune correlates leading to chronicity. The conditions of immunocompromised patients were mimicked by treating pigs with an immunosuppressive regimen including cyclosporine, azathioprine, and prednisolone. Immunocompromised pigs infected with HEV progressed to chronicity, because 8/10 drug-treated HEV-infected pigs continued fecal virus shedding beyond the acute phase of infection, whereas the majority (7/10) of mock-treated HEV-infected pigs cleared fecal viral shedding at 8 wk postinfection. During chronic infection, serum levels of the liver enzyme γ-glutamyl transferase and fecal virus shedding were significantly higher in immunocompromised HEV-infected pigs. To identify potential immune correlates of chronic infection, we determined serum levels of cytokines and cell-mediated immune responses in pigs. Results showed that HEV infection of immunocompromised pigs reduced the serum levels of Th1 cytokines IL-2 and IL-12, and Th2 cytokines IL-4 and IL-10, particularly during the acute phase of infection. Furthermore IFN-γ–specific CD4+ T-cell responses were reduced in immunocompromised pigs during the acute phase of infection, but TNF-α–specific CD8+ T-cell responses increased during the chronic phase of infection. Thus, active suppression of cell-mediated immune responses under immunocompromised conditions may facilitate the establishment of chronic HEV infection. This pig model will aid in delineating the mechanisms of chronic HEV infection and in developing effective therapeutics against chronic hepatitis E. PMID:28630341

Pig model mimicking chronic hepatitis E virus infection in immunocompromised patients to assess immune correlates during chronicity.

PubMed

Cao, Dianjun; Cao, Qian M; Subramaniam, Sakthivel; Yugo, Danielle M; Heffron, C Lynn; Rogers, Adam J; Kenney, Scott P; Tian, Debin; Matzinger, Shannon R; Overend, Christopher; Catanzaro, Nicholas; LeRoith, Tanya; Wang, Heng; Piñeyro, Pablo; Lindstrom, Nicole; Clark-Deener, Sherrie; Yuan, Lijuan; Meng, Xiang-Jin

2017-07-03

Chronic hepatitis E virus (HEV) infection is a significant clinical problem in immunocompromised individuals such as organ transplant recipients, although the mechanism remains unknown because of the lack of an animal model. We successfully developed a pig model of chronic HEV infection and examined immune correlates leading to chronicity. The conditions of immunocompromised patients were mimicked by treating pigs with an immunosuppressive regimen including cyclosporine, azathioprine, and prednisolone. Immunocompromised pigs infected with HEV progressed to chronicity, because 8/10 drug-treated HEV-infected pigs continued fecal virus shedding beyond the acute phase of infection, whereas the majority (7/10) of mock-treated HEV-infected pigs cleared fecal viral shedding at 8 wk postinfection. During chronic infection, serum levels of the liver enzyme γ-glutamyl transferase and fecal virus shedding were significantly higher in immunocompromised HEV-infected pigs. To identify potential immune correlates of chronic infection, we determined serum levels of cytokines and cell-mediated immune responses in pigs. Results showed that HEV infection of immunocompromised pigs reduced the serum levels of Th1 cytokines IL-2 and IL-12, and Th2 cytokines IL-4 and IL-10, particularly during the acute phase of infection. Furthermore IFN-γ-specific CD4 + T-cell responses were reduced in immunocompromised pigs during the acute phase of infection, but TNF-α-specific CD8 + T-cell responses increased during the chronic phase of infection. Thus, active suppression of cell-mediated immune responses under immunocompromised conditions may facilitate the establishment of chronic HEV infection. This pig model will aid in delineating the mechanisms of chronic HEV infection and in developing effective therapeutics against chronic hepatitis E.

[Chronic active Epstein-Barr virus infection].

PubMed

Kimura, Hiroshi

2011-12-01

The ubiquitous Epstein-Barr virus (EBV), which establishes latency after primary infection, does not cause any symptomatic diseases as long as cellular immunity is intact. In apparently immunocompetent individuals, a chronic infection can develop, and this has been called as chronic active EBV infection (CAEBV). CAEBV is characterized by chronic or recurrent infectious mononucleosis-like symptoms, such as fever, extensive lymphadenopathy, and, hepatosplenomegaly. This disease is rare but severe with high morbidity and mortality. Recently, its pathophysiology is not an infection but a clonal expansion of EBV-infected T or natural killer NK cells. In this review, I discuss our current understanding of the pathogenesis of CAEBV and summarize its clinical features, therapies, and prognosis.

Mast Cell IL-10 Drives Localized Tolerance in Chronic Bladder Infection

PubMed Central

Chan, Cheryl Y.; St. John, Ashley L.; Abraham, Soman N.

2013-01-01

The lower urinary tract’s virtually inevitable exposure to external microbial pathogens warrants efficient tissue-specialized defenses to maintain sterility. The observation that the bladder can become chronically infected in combination with clinical observations that antibody responses following bladder infections are not detectable, suggest defects in the formation of adaptive immunity and immunological memory. We have identified a broadly immunosuppressive transcriptional program specific to the bladder, but not the kidney, during infection of the urinary tract that is dependent on tissue-resident mast cells (MCs). This involves localized production of interleukin-10 and results in suppressed humoral and cell mediated responses and bacterial persistence. Therefore, in addition to the previously described role of MCs orchestrating the early innate immunity during bladder infection, they subsequently play a tissue-specific immunosuppressive role. These findings may explain the prevalent recurrence of bladder infections and suggest the bladder as a site exhibiting an intrinsic degree of MC-maintained immune privilege. PMID:23415912

Prognostic factors for chronic active Epstein-Barr virus infection.

PubMed

Kimura, Hiroshi; Morishima, Tsuneo; Kanegane, Hirokazu; Ohga, Shouichi; Hoshino, Yo; Maeda, Akihiko; Imai, Shosuke; Okano, Motohiko; Morio, Tomohiro; Yokota, Shumpei; Tsuchiya, Shigeru; Yachie, Akihiro; Imashuku, Shinsaku; Kawa, Keisei; Wakiguchi, Hiroshi

2003-02-15

Chronic active Epstein-Barr virus infection (CAEBV) is a high-mortality and high-morbidity disease. To clarify the prognostic factors, a national survey was performed in Japan, and data for 82 patients who met the criteria for CAEBV were analyzed. Of these 82 patients, 47 were alive and 35 had already died. Multivariate analysis revealed that thromobocytopenia and age at disease onset were correlated with mortality. The probability of 5-year survival was 0.45 for older patients (onset age, > or = 8 years), 0.94 for younger patients (P<.001), 0.38 for patients with thrombocytopenia (platelet count < 12 x 10(4) platelets/microL at diagnosis), and 0.76 for patients without thrombocytopenia (P=.01). Furthermore, patients with T cell infection by EBV had shorter survival times than patients with natural killer cell infection (probability of 5-year survival, 0.59 vs. 0.87; P<.009). Patients with CAEBV with late onset of disease, thrombocytopenia, and T cell infection had significantly poorer outcomes.

EBV Chronic Infections

PubMed Central

Eligio, Pizzigallo; Delia, Racciatti; Valeria, Gorgoretti

2010-01-01

these studies it was possibile to confirm the etiologic links between the syndrome and EBV or other herpesviruses or other persistent infectious agents. The mechanisms of EBV latency have been carefully examined both because they represent the virus strategy to elude the response of the immune system of the host, and because they are correlated with those oncologic conditions associated to the viral persistence, particularly lymphomas and lymphoproliferative disorders. Just these malignancies, for which a pathogenetic role of EBV is clearly documented, should represent the main clinical expression of a first group of chronic EBV infections characterized by a natural history where the neoplastic event aroused from the viral persistence in the resting B cells for all the life, from the genetic predisposition of the host and from the oncogenic potentialities of the virus that chronically persists and incurs reactivations. Really, these oncological diseases should be considered more complications than chronic forms of the illness, as well as other malignancies for which a viral – or even infectious - etiology is well recognized. The chronic diseases, in fact, should be linked in a pathogenetic and temporal way to the acute infection, from whom start the natural history of the following disease. So, as for the chronic liver diseases from HBV and HCV, it was conied the acronym of CAEBV (Chronic Active EBV infection), distinguishing within these pathologies the more severe forms (SCAEBV) mostly reported in Far East and among children or adolescents. Probably only these forms have to be considered expressions of a chronic EBV infection “sensu scrictu”, together with those forms of CFS where the etiopathogenetic and temporal link with the acute EBV infection is well documented. As for CFS, also for CAEBV the criteria for a case definition were defined, even on the basis of serological and virological findings. However, the lymphoproliferative disorders are excluded from

Impaired Subset Progression and Polyfunctionality of T Cells in Mice Exposed to Methamphetamine during Chronic LCMV Infection

PubMed Central

Sriram, Uma; Hill, Beth L.; Cenna, Jonathan M.; Gofman, Larisa; Fernandes, Nicole C.; Haldar, Bijayesh; Potula, Raghava

2016-01-01

Methamphetamine (METH) is a widely used psychostimulant that severely impacts the host’s innate and adaptive immune systems and has profound immunological implications. T cells play a critical role in orchestrating immune responses. We have shown recently how chronic exposure to METH affects T cell activation using a murine model of lymphocytic choriomeningitis virus (LCMV) infection. Using the TriCOM (trinary state combinations) feature of GemStone™ to study the polyfunctionality of T cells, we have analyzed how METH affected the cytokine production pattern over the course of chronic LCMV infection. Furthermore, we have studied in detail the effects of METH on splenic T cell functions, such as cytokine production and degranulation, and how they regulate each other. We used the Probability State Modeling (PSM) program to visualize the differentiation of effector/memory T cell subsets during LCMV infection and analyze the effects of METH on T cell subset progression. We recently demonstrated that METH increased PD-1 expression on T cells during viral infection. In this study, we further analyzed the impact of PD-1 expression on T cell functional markers as well as its expression in the effector/memory subsets. Overall, our study indicates that analyzing polyfunctionality of T cells can provide additional insight into T cell effector functions. Analysis of T cell heterogeneity is important to highlight changes in the evolution of memory/effector functions during chronic viral infections. Our study also highlights the impact of METH on PD-1 expression and its consequences on T cell responses. PMID:27760221

Impaired Subset Progression and Polyfunctionality of T Cells in Mice Exposed to Methamphetamine during Chronic LCMV Infection.

PubMed

Sriram, Uma; Hill, Beth L; Cenna, Jonathan M; Gofman, Larisa; Fernandes, Nicole C; Haldar, Bijayesh; Potula, Raghava

2016-01-01

Methamphetamine (METH) is a widely used psychostimulant that severely impacts the host's innate and adaptive immune systems and has profound immunological implications. T cells play a critical role in orchestrating immune responses. We have shown recently how chronic exposure to METH affects T cell activation using a murine model of lymphocytic choriomeningitis virus (LCMV) infection. Using the TriCOM (trinary state combinations) feature of GemStone™ to study the polyfunctionality of T cells, we have analyzed how METH affected the cytokine production pattern over the course of chronic LCMV infection. Furthermore, we have studied in detail the effects of METH on splenic T cell functions, such as cytokine production and degranulation, and how they regulate each other. We used the Probability State Modeling (PSM) program to visualize the differentiation of effector/memory T cell subsets during LCMV infection and analyze the effects of METH on T cell subset progression. We recently demonstrated that METH increased PD-1 expression on T cells during viral infection. In this study, we further analyzed the impact of PD-1 expression on T cell functional markers as well as its expression in the effector/memory subsets. Overall, our study indicates that analyzing polyfunctionality of T cells can provide additional insight into T cell effector functions. Analysis of T cell heterogeneity is important to highlight changes in the evolution of memory/effector functions during chronic viral infections. Our study also highlights the impact of METH on PD-1 expression and its consequences on T cell responses.

Biclonal expansion of T cells infected with monoclonal Epstein–Barr virus (EBV) in a patient with chronic, active EBV infection

PubMed Central

TOYABE, S; HARADA, W; UCHIYAMA, M

2003-01-01

Recent studies have suggested that a high percentage of Epstein–Barr virus (EBV)-infected lymphocytes in peripheral blood of patients with chronic, active EBV infection (CAEBV) is of T cell origin. Although T cells are expanded oligoclonally in CAEBV, it is not clear whether the restricted diversity of T cells arise from immune reaction against EBV-related antigens or from proliferation of EBV-infected cells. We experienced a patient with CAEBV who had biclonal expansion of peripheral blood T cells. We identified clonotypes of these two T cell clones in detail and purified the T cell clones. EBV infected mainly the two T cell clones, whereas the viral loads in peripheral blood cells other than these T cell clones were low or undetectable. The EBV strains infecting the two T cells clones were indistinguishable from each other by a series of genotype analyses of the virus. These results suggest that the two T cell clones infected with the same monoclonal EBV proliferated in peripheral blood of the patient. PMID:12974760

Induction of Type I Interferons by Therapeutic Nanoparticle-Based Vaccination Is Indispensable to Reinforce Cytotoxic CD8+ T Cell Responses During Chronic Retroviral Infection

PubMed Central

Knuschke, Torben; Rotan, Olga; Bayer, Wibke; Kollenda, Sebastian; Dickow, Julia; Sutter, Kathrin; Hansen, Wiebke; Dittmer, Ulf; Lang, Karl S.; Epple, Matthias; Buer, Jan; Westendorf, Astrid M.

2018-01-01

T cell dysfunction and immunosuppression are characteristic for chronic viral infections and contribute to viral persistence. Overcoming these burdens is the goal of new therapeutic strategies to cure chronic infectious diseases. We recently described that therapeutic vaccination of chronic retrovirus infected mice with a calcium phosphate (CaP) nanoparticle (NP)-based vaccine carrier, functionalized with CpG and viral peptides is able to efficiently reactivate the CD8+ T cell response and improve the eradication of virus infected cells. However, the mechanisms underlying this effect were largely unclear. While type I interferons (IFNs I) are considered to drive T cell exhaustion by persistent immune activation during chronic viral infection, we here describe an indispensable role of IFN I induced by therapeutic vaccination to efficiently reinforce cytotoxic CD8+ T cells (CTL) and improve control of chronic retroviral infection. The induction of IFN I is CpG dependent and leads to significant IFN signaling indicated by upregulation of IFN stimulated genes. By vaccinating chronically retrovirus-infected mice lacking the IFN I receptor (IFNAR−/−) or by blocking IFN I signaling in vivo during therapeutic vaccination, we demonstrate that IFN I signaling is necessary to drive full reactivation of CTLs. Surprisingly, we also identified an impaired suppressive capability of regulatory T cells in the presence of IFNα, which implicates an important role for vaccine-induced IFNα in the regulation of the T cell response during chronic retroviral infection. Our data suggest that inducing IFN I signaling in conjunction with the presentation of viral antigens can reactivate immune functions and reduce viral loads in chronic infections. Therefore, we propose CaP NPs as potential therapeutic tool to treat chronic infections. PMID:29740425

Features of Effective T Cell-Inducing Vaccines against Chronic Viral Infections

PubMed Central

Panagioti, Eleni; Klenerman, Paul; Lee, Lian N.; van der Burg, Sjoerd H.; Arens, Ramon

2018-01-01

For many years, the focus of prophylactic vaccines was to elicit neutralizing antibodies, but it has become increasingly evident that T cell-mediated immunity plays a central role in controlling persistent viral infections such as with human immunodeficiency virus, cytomegalovirus, and hepatitis C virus. Currently, various promising prophylactic vaccines, capable of inducing substantial vaccine-specific T cell responses, are investigated in preclinical and clinical studies. There is compelling evidence that protection by T cells is related to the magnitude and breadth of the T cell response, the type and homing properties of the memory T cell subsets, and their cytokine polyfunctionality and metabolic fitness. In this review, we evaluated these key factors that determine the qualitative and quantitative properties of CD4+ and CD8+ T cell responses in the context of chronic viral disease and prophylactic vaccine development. Elucidation of the mechanisms underlying T cell-mediated protection against chronic viral pathogens will facilitate the development of more potent, durable and safe prophylactic T cell-based vaccines. PMID:29503649

Altered distribution of peripheral blood memory B cells in humans chronically infected with Trypanosoma cruzi.

PubMed

Fernández, Esteban R; Olivera, Gabriela C; Quebrada Palacio, Luz P; González, Mariela N; Hernandez-Vasquez, Yolanda; Sirena, Natalia María; Morán, María L; Ledesma Patiño, Oscar S; Postan, Miriam

2014-01-01

Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans.

Altered Distribution of Peripheral Blood Memory B Cells in Humans Chronically Infected with Trypanosoma cruzi

PubMed Central

Fernández, Esteban R.; Olivera, Gabriela C.; Quebrada Palacio, Luz P.; González, Mariela N.; Hernandez-Vasquez, Yolanda; Sirena, Natalia María; Morán, María L.; Ledesma Patiño, Oscar S.; Postan, Miriam

2014-01-01

Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans. PMID:25111833

Inflammatory Flt3L is essential to mobilize dendritic cells and for T cell responses during Plasmodium infection

PubMed Central

Guermonprez, Pierre; Helft, Julie; Claser, Carla; Deroubaix, Stephanie; Karanje, Henry; Gazumyan, Anna; Darrasse-Jeze, Guillaume; Telerman, Stephanie B.; Breton, Gaëlle; Schreiber, Heidi A.; Frias-Staheli, Natalia; Billerbeck, Eva; Dorner, Marcus; Rice, Charles M.; Ploss, Alexander; Klein, Florian; Swiecki, Melissa; Colonna, Marco; Kamphorst, Alice O.; Meredith, Matthew; Niec, Rachel; Takacs, Constantin; Mikhail, Fadi; Hari, Aswin; Bosque, David; Eisenreich, Tom; Merad, Miriam; Shi, Yan; Ginhoux, Florent; Rénia, Laurent; Urban, Britta C.; Nussenzweig, Michel C.

2014-01-01

Summary Innate sensing mechanisms trigger a variety of humoral and cellular events that are essential to adaptive immune responses. Here we describe an innate sensing pathway triggered by Plasmodium infection that regulates dendritic cell (DC) homeostasis and adaptive immunity via Flt3L release. Plasmodium-induced Flt3L release requires toll-like receptor activation and type I interferon production. We find that type I interferon supports the up-regulation of xanthine dehydrogenase, which metabolizes the xanthine accumulating in infected erythrocytes to uric acid. Uric acid crystals trigger mast cells to release soluble Flt3L from a pre-synthesized membrane-associated precursor. During infection Flt3L preferentially stimulates expansion of the CD8α+/CD103+ DC subset or its BDCA3+ human DC equivalent and has a significant impact on the magnitude of T cell activation, mostly in the CD8+ compartment. Our findings highlight a new mechanism that regulates DC homeostasis and T cell responses to infection. PMID:23685841

Sofosbuvir and Simeprevir Treatment of a Stem Cell Transplanted Teenager With Chronic Hepatitis C Infection.

PubMed

Fischler, Björn; Priftakis, Peter; Sundin, Mikael

2016-06-01

There have been no previous reports on the use of interferon-free combinations in pediatric patients with chronic hepatitis C infection. An infected adolescent with severe sickle cell disease underwent stem cell transplantation and subsequent treatment with sofosbuvir and simeprevir during ongoing immunosuppression. Despite the emergence of peripheral edema as a side effect, treatment was continued with sustained antiviral response.

Aggressive Peripheral CD70-positive T-cell Lymphoma Associated with Severe Chronic Active EBV Infection

PubMed Central

Shaffer, Donald R.; Sheehan, Andrea M.; Yi, Zhongzhen; Rodgers, Cheryl C; Bollard, Catherine M; Brenner, Malcolm K; Rooney, Cliona M; Heslop, Helen E; Gottschalk, Stephen

2011-01-01

Severe chronic active Epstein-Barr virus infection (CAEBV) in T or NK cells is a rare complication of latent EBV infection. CAEBV associated T-cell lymphoproliferative disease (LPD) consists of polyclonal lesions as well as aggressive lymphomas. Here we report such a patient. In addition, we show that this primary CAEBV associated T-cell lymphoma expresses CD70 and is sensitive to killing by CD70-specific T cells, identifying CD70 as a potential immunotherapeutic target for CAEBV-associated T-cell lymphoma. PMID:21994111

[Expressions and significance of TLR2 and TLR4 in Kupffer cells of tree shrews chronically infected with hepatitis B virus].

PubMed

Ruan, Ping; Yang, Chun; Su, Jianjia; Ou, Chao; Cao, Ji; Luo, Chengpiao; Tang, Yanping; Qin, Hong; Sun, Wen; Li, Yuan

2014-07-01

To investigate the mRNA expression levels of Toll-like receptors 2 (TLR2) and TLR4 in Kupffer cells of tree shrews that were chronically infected with hepatitis B virus (HBV), and the effects of these receptors on the function of Kupffer cells. The tree shrews were divided into tree shrews proved with chronic HBV infection, tree shrews suspected with chronic HBV infection, and normal control tree shrews without hepatitis B vaccination. The samples of serum and liver biopsy were collected periodically, and the levels of HBV DNA in serum and liver tissues were detected by fluorescence-based quantitative real-time PCR (qRT-PCR). Meanwhile, Kupffer cells were isolated from the biopsied liver tissues, and then purified and primarily cultured. Afterwards, qRT-PCR was applied to detect the mRNA expression levels of TLR2, TLR4 and TNF-α in the Kupffer cells. Cell migration assay and lysosome-specific fluorescent probe were adopted to analyze the effects of TLR2 and TLR4 on the migration capacity of Kupffer cells and the quantity of lysosomes in these cells. The mRNA expression levels of TLR2 and TLR4 in tree shrews proved with chronic HBV infection were lower than those in the ones suspected with chronic HBV infection and normal controls without hepatitis B vaccination (P<0.05), and these expression levels were all negatively correlated with the level of HBV DNA in liver tissues of the animals (P<0.05), but were positively correlated with the number of migrated Kupffer cells, the density of lysosomes and the mRNA expression level of TNF-α (P<0.05). TLR2 and TLR4 in Kupffer cells may play important roles in the chronic process of hepatic pathological changes in tree shrews infected with HBV through their influence on the function of Kupffer cells.

Aggressive peripheral CD70-positive T-cell lymphoma associated with severe chronic active EBV infection.

PubMed

Shaffer, Donald R; Sheehan, Andrea M; Yi, Zhongzhen; Rodgers, Cheryl C; Bollard, Catherine M; Brenner, Malcolm K; Rooney, Cliona M; Heslop, Helen E; Gottschalk, Stephen

2012-10-01

Severe chronic active Epstein-Barr virus infection (CAEBV) in T or NK cells is a rare complication of latent EBV infection. CAEBV associated T-cell lymphoproliferative disease (LPD) consists of polyclonal lesions as well as aggressive lymphomas. Here, we report such a patient. In addition, we show that this primary CAEBV associated T-cell lymphoma expresses CD70 and is sensitive to killing by CD70-specific T cells, identifying CD70 as a potential immunotherapeutic target for CAEBV-associated T-cell lymphoma. Copyright © 2011 Wiley Periodicals, Inc.

Ear infection - chronic

MedlinePlus

Middle ear infection - chronic; Otitis media - chronic; Chronic otitis media; Chronic ear infection ... Chole RA. Chronic otitis media, mastoiditis, and petrositis. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology: Head & Neck Surgery . 6th ed. ...

Impact of Chronic Viral Infection on T-Cell Dependent Humoral Immune Response.

PubMed

Rodriguez, Stéphane; Roussel, Mikaël; Tarte, Karin; Amé-Thomas, Patricia

2017-01-01

During the last decades, considerable efforts have been done to decipher mechanisms supported by microorganisms or viruses involved in the development, differentiation, and function of immune cells. Pathogens and their associated secretome as well as the continuous inflammation observed in chronic infection are shaping both innate and adaptive immunity. Secondary lymphoid organs are functional structures ensuring the mounting of adaptive immune response against microorganisms and viruses. Inside these organs, germinal centers (GCs) are the specialized sites where mature B-cell differentiation occurs leading to the release of high-affinity immunoglobulin (Ig)-secreting cells. Different steps are critical to complete B-cell differentiation process, including proliferation, somatic hypermutations in Ig variable genes, affinity-based selection, and class switch recombination. All these steps require intense interactions with cognate CD4 + helper T cells belonging to follicular helper lineage. Interestingly, pathogens can disturb this subtle machinery affecting the classical adaptive immune response. In this review, we describe how viruses could act directly on GC B cells, either through B-cell infection or by their contribution to B-cell cancer development and maintenance. In addition, we depict the indirect impact of viruses on B-cell response through infection of GC T cells and stromal cells, leading to immune response modulation.

Pathway analysis in blood cells of pigs infected with classical swine fever virus: comparison of pigs that develop a chronic form of infection or recover.

PubMed

Hulst, Marcel; Loeffen, Willie; Weesendorp, Eefke

2013-02-01

Infection of pigs with CSFV can lead to either acute disease, resulting in death or recovery, or chronic disease. The mechanisms by which CSFV manipulates the pig's first line of defence to establish a chronic infection are poorly understood. Therefore, pigs were infected with moderately virulent CSFV, and whole blood was collected on a regular basis during a period of 18 days. Using whole-genome microarrays, time-dependent changes in gene expression were recorded in blood cells of chronically diseased pigs and pigs that recovered. Bioinformatics analysis of regulated genes indicated that different immunological pathways were regulated in chronically diseased pigs compared to recovered pigs. In recovered pigs, antiviral defence mechanisms were rapidly activated, whereas in chronically diseased pigs, several genes with the potential to inhibit NF-κB- and IRF3/7-mediated transcription of type I interferons were up-regulated. Compared to recovered pigs, chronically diseased pigs failed to activate NK or cytotoxic T-cell pathways, and they showed decreased gene activity in antigen-presenting monocytes/macrophages. Remarkably, in chronically diseased pigs, genes related to the human autoimmune disease systemic lupus erythematosus (SLE) were up-regulated during the whole period of 18 days. CSFV pathology in kidney and skin resembles that of SLE. Furthermore, enzymes involved in the degradation of 1,25-dihydroxyvitamin D3 and of tryptophan to kynurenines were expressed at different levels in chronically diseased and recovered pigs. Both of these chemical processes may affect the functions of T helper/regulatory cells that are crucial for tempering the inflammatory response after a viral infection.

Soluble CD40-ligand (sCD40L, sCD154) plays an immunosuppressive role via regulatory T cell expansion in HIV infection

PubMed Central

Jenabian, M-A; Patel, M; Kema, I; Vyboh, K; Kanagaratham, C; Radzioch, D; Thébault, P; Lapointe, R; Gilmore, N; Ancuta, P; Tremblay, C; Routy, J-P

2014-01-01

CD40/CD40-ligand (CD40L) signalling is a key stimulatory pathway which triggers the tryptophan (Trp) catabolizing enzyme IDO in dendritic cells and is immunosuppressive in cancer. We reported IDO-induced Trp catabolism results in a T helper type 17 (Th17)/regulatory T cell (Treg) imbalance, and favours microbial translocation in HIV chronic infection. Here we assessed the link between sCD40L, Tregs and IDO activity in HIV-infected patients with different clinical outcomes. Plasmatic sCD40L and inflammatory cytokines were assessed in anti-retroviral therapy (ART)-naive, ART-successfully treated (ST), elite controllers (EC) and healthy subjects (HS). Plasma levels of Trp and its metabolite Kynurenine (Kyn) were measured by isotope dilution tandem mass spectrometry and sCD14 was assessed by enzyme-linked immunosorbent assay (ELISA). IDO-mRNA expression was quantified by reverse transcription–polymerase chain reaction (RT–PCR). The in-vitro functional assay of sCD40L on Treg induction and T cell activation were assessed on peripheral blood mononuclear cells (PBMCs) from HS. sCD40L levels in ART-naive subjects were significantly higher compared to ST and HS, whereas EC showed only a minor increase. In ART-naive alone, sCD40L was correlated with T cell activation, IDO-mRNA expression and CD4 T cell depletion but not with viral load. sCD40L was correlated positively with IDO enzymatic activity (Kyn/Trp ratio), Treg frequency, plasma sCD14 and inflammatory soluble factors in all HIV-infected patients. In-vitro functional sCD40L stimulation induced Treg expansion and favoured Treg differentiation by reducing central memory and increasing terminal effector Treg proportion. sCD40L also increased T cell activation measured by co-expression of CD38/human leucocyte antigen D-related (HLA-DR). These results indicate that elevated sCD40L induces immunosuppression in HIV infection by mediating IDO-induced Trp catabolism and Treg expansion. PMID:24924152

Soluble CD40-ligand (sCD40L, sCD154) plays an immunosuppressive role via regulatory T cell expansion in HIV infection.

PubMed

Jenabian, M-A; Patel, M; Kema, I; Vyboh, K; Kanagaratham, C; Radzioch, D; Thébault, P; Lapointe, R; Gilmore, N; Ancuta, P; Tremblay, C; Routy, J-P

2014-10-01

CD40/CD40-ligand (CD40L) signalling is a key stimulatory pathway which triggers the tryptophan (Trp) catabolizing enzyme IDO in dendritic cells and is immunosuppressive in cancer. We reported IDO-induced Trp catabolism results in a T helper type 17 (Th17)/regulatory T cell (Treg ) imbalance, and favours microbial translocation in HIV chronic infection. Here we assessed the link between sCD40L, Tregs and IDO activity in HIV-infected patients with different clinical outcomes. Plasmatic sCD40L and inflammatory cytokines were assessed in anti-retroviral therapy (ART)-naive, ART-successfully treated (ST), elite controllers (EC) and healthy subjects (HS). Plasma levels of Trp and its metabolite Kynurenine (Kyn) were measured by isotope dilution tandem mass spectrometry and sCD14 was assessed by enzyme-linked immunosorbent assay (ELISA). IDO-mRNA expression was quantified by reverse transcription-polymerase chain reaction (RT-PCR). The in-vitro functional assay of sCD40L on Treg induction and T cell activation were assessed on peripheral blood mononuclear cells (PBMCs) from HS. sCD40L levels in ART-naive subjects were significantly higher compared to ST and HS, whereas EC showed only a minor increase. In ART-naive alone, sCD40L was correlated with T cell activation, IDO-mRNA expression and CD4 T cell depletion but not with viral load. sCD40L was correlated positively with IDO enzymatic activity (Kyn/Trp ratio), Treg frequency, plasma sCD14 and inflammatory soluble factors in all HIV-infected patients. In-vitro functional sCD40L stimulation induced Treg expansion and favoured Treg differentiation by reducing central memory and increasing terminal effector Treg proportion. sCD40L also increased T cell activation measured by co-expression of CD38/human leucocyte antigen D-related (HLA-DR). These results indicate that elevated sCD40L induces immunosuppression in HIV infection by mediating IDO-induced Trp catabolism and Treg expansion. © 2014 British Society for Immunology.

Frequency of Th17 cells correlates with the presence of lung lesions in pigs chronically infected with Actinobacillus pleuropneumoniae.

PubMed

Sassu, Elena L; Ladinig, Andrea; Talker, Stephanie C; Stadler, Maria; Knecht, Christian; Stein, Heiko; Frömbling, Janna; Richter, Barbara; Spergser, Joachim; Ehling-Schulz, Monika; Graage, Robert; Hennig-Pauka, Isabel; Gerner, Wilhelm

2017-02-06

Porcine contagious pleuropneumonia caused by Actinobacillus pleuropneumoniae (APP) remains one of the major causes of poor growth performance and respiratory disease in pig herds. While the role of antibodies against APP has been intensely studied, the porcine T cell response remains poorly characterized. To address this, pigs were intranasally infected with APP serotype 2 and euthanized during the acute phase [6-10 days post-infection (dpi)] or the chronic phase of APP infection (27-31 dpi). Lymphocytes isolated from blood, tonsils, lung tissue and tracheobronchial lymph nodes were analyzed by intracellular cytokine staining (ICS) for IL-17A, IL-10 and TNF-α production after in vitro stimulation with crude capsular extract (CCE) of the APP inoculation strain. This was combined with cell surface staining for the expression of CD4, CD8α and TCR-γδ. Clinical records, microbiological investigations and pathological findings confirmed the induction of a subclinical APP infection. ICS-assays revealed the presence of APP-CCE specific CD4 + CD8α dim IL-17A-producing T cells in blood and lung tissue in most infected animals during the acute and chronic phase of infection and a minor fraction of these cells co-produced TNF-α. APP-CCE specific IL-17A-producing γδ T cells could not be found and APP-CCE specific IL-10-producing CD4 + T cells were present in various organs but only in a few infected animals. The frequency of identified putative Th17 cells (CD4 + CD8α dim IL-17A + ) in lung and blood correlated positively with lung lesion scores and APP-specific antibody titers during the chronic phase. These results suggest a potential role of Th17 cells in the immune pathogenesis of APP infection.

gC1qR expression in chimpanzees with resolved and chronic infection: Potential role of HCV core/gC1qR-mediated T cell suppression in the outcome of HCV infection

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

Yao Zhiqang; Shata, Mohamed Tarek; Tricoche, Nancy

2006-03-15

Chimpanzee is a unique animal model for HCV infection, in which about 50% of infections resolve spontaneously. It has been reported that the magnitude of T cell responses to HCV core in recovered chimpanzees is greater than that in chronically infected ones. However, the mechanism(s) by which the chimpanzees with resolved infection overcome core-mediated immunosuppression remains unknown. In this study, we examined the effect of HCV core on T cell responsiveness in chimpanzees with resolved and chronic HCV infection. We found that core protein strongly inhibited T cell activation and proliferation in chimpanzees with chronic infection, while this inhibition wasmore » limited in chimpanzees with resolved infection. Notably, the level of gC1qR, as well as the binding of core protein, on the surface of T cells was lower in recovered chimpanzees when compared to chimpanzees with chronic HCV infection. Intriguingly, the observed differences in gC1qR expression levels and susceptibility to core-induced suppression amongst HCV-chronically infected and recovered chimpanzees were observed prior to HCV challenge, suggesting a possible genetic determination of the outcome of infection. These findings suggest that gC1qR expression on the surface of T cells is crucial for HCV core-mediated T cell suppression and viral clearance, and that represents a novel mechanism by which a virus usurps host machinery for persistence.« less

Lack of Siglec-7 expression identifies a dysfunctional natural killer cell subset associated with liver inflammation and fibrosis in chronic HCV infection.

PubMed

Varchetta, Stefania; Mele, Dalila; Lombardi, Andrea; Oliviero, Barbara; Mantovani, Stefania; Tinelli, Carmine; Spreafico, Marta; Prati, Daniele; Ludovisi, Serena; Ferraioli, Giovanna; Filice, Carlo; Aghemo, Alessio; Lampertico, Pietro; Facchetti, Floriana; Bernuzzi, Francesca; Invernizzi, Pietro; Mondelli, Mario U

2016-12-01

Sialic-acid-binding immunoglobulin-like lectin-7 (Siglec-7) is a natural killer (NK) cell inhibitory receptor associated with NK phenotypic and functional abnormalities in HIV-1 infection. We investigated the significance of NK-expressed and serum soluble Siglec-7 in relation to NK functional ability and parameters of liver necroinflammation and fibrosis in chronic HCV infection. NK-expressed and serum Siglec-7 were evaluated in 130 and 166 HCV-infected individuals by flow cytometry and ELISA, respectively. NK cell degranulation and cytokine secretion were determined by flow cytometry. 65 patients with chronic HBV infection, 84 with chronic biliary disorders and 168 healthy donors served as controls. Expression of Siglec-7 was significantly decreased on NK cells from HCV-infected and HBV-infected patients and, conversely, serum Siglec-7 was significantly increased in these patients compared with controls. The frequency of Siglec-7pos NK cells was significantly higher at baseline in sustained virological responders to pegylated interferon-α/ribavirin treatment than in non-responders. Activating receptor expression was significantly higher in Siglec-7pos NK cells and was associated with increased degranulation and cytokine secretion compared with Siglec-7 neg cells. In chronic HCV infection, there was an inverse correlation between Siglec-7 expression and serum aminotransferases, γ-glutamyl transpeptidase, liver stiffness, aspartate aminotransferase to platelet ratio index and fibrosis-4 scores, and a positive correlation between serum Siglec-7 and the same clinical parameters, including histological staging. These findings identify Siglec-7 neg NK cells as a dysfunctional subpopulation associated with severe liver disease in chronic HCV infection. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Experimental infection of Leishmania (L.) chagasi in a cell line derived from Lutzomyia longipalpis (Diptera:Psychodidae).

PubMed

Bello, Felio J; Mejía, Astrid J; Corena, María del Pilar; Ayala, Martha; Sarmiento, Ladys; Zuñiga, Claudio; Palau, María T

2005-10-01

The present work describes the in vitro infection of a cell line Lulo, derived from Lutzomyia longipalpis embryonic tissue, by Leishmania chagasi promastigotes. This infection process is compared with a parallel one developed using the J774 cell line. The L. chagasi MH/CO/84/CI-044B strain was used for experimental infection in two cell lines. The cells were seeded on glass coverslips in 24-well plates to reach a final number of 2 x 10(5) cells/well. Parasites were added to the adhered Lulo and J774 cells in a 10:1 ratio and were incubated at 28 and 37 masculineC respectively. After 2, 4, 6, 8, and 10 days post-infection, the cells were extensively washed with PBS, fixed with methanol, and stained with Giemsa. The number of internalized parasites was determined by counting at least 400 cultured cells on each coverslip. The results showed continuous interaction between L. chagasi promastigotes with the cell lines. Some ultrastructural characteristics of the amastigote forms were observed using transmission electron microscopy. The highest percentage of infection in Lulo cells was registered on day 6 post-infection (29.6%) and on day 4 in the J774 cells (51%). This work shows similarities and differences in the L. chagasi experimental infection process in the two cell lines. However, Lulo cells emerge as a new model to study the life-cycle of this parasite.

CD95 (Fas) ligand expression of Epstein-Barr virus (EBV)-infected lymphocytes: a possible mechanism of immune evasion in chronic active EBV infection.

PubMed

Ohshima, K; Suzumiya, J; Sugihara, M; Nagafuchi, S; Ohga, S; Kikuchi, M

1999-01-01

The Epstein-Barr virus (EBV) induces infectious mononucleosis (IM) and can be associated with chronic active EBV infection (CAEBV). Cytotoxic T lymphocytes (CTL) play an important role in excluding EBV-infected cells. Two cytotoxic mechanisms of CTL have been demonstrated: one perforin/granzyme-based and the other Fas (CD95)/Fas ligand (FasL)-based. To clarify these two pathways in CAEBV, we analyzed six patients with CAEBV and four patients with IM using immunohistochemical staining of the lymph nodes. In both CAEBV and IM, CD8+ T-cells increased in number, but CD56+ natural killer cells were rare. In four of six cases with CAEBV, approximately half the lymphocytes were positive for T cell-restricted intracellular antigens (TIA-1), which were recognized by the cytolytic granules of CTL. In IM, the number of TIA-1 positive cells was smaller than that in CAEBV. Fas-positive lymphocytes were frequently encountered in both CAEBV and IM. However, FasL-positive lymphocytes increased in three of six patients with CAEBV, but not in patients with IM. Except for one case with CAEBV, the number of perforin- and/or granzyme-positive cells was small in number in both CAEBV and IM cases. In double-staining FasL and EBV in situ hybridization, FasL-positive EBV-infected lymphocytes were detected in CAEBV but not in IM. In CAEBV, the Fas/FasL pathway and not perforin pathways appears to play an important role in the pathogenesis. The data suggest that EBV-infected lymphocytes may evade immune attack through the expression of FasL.

L-selectin Is Essential for Delivery of Activated CD8+ T Cells to Virus-Infected Organs for Protective Immunity

PubMed Central

Mohammed, Rebar N.; Watson, H. Angharad; Vigar, Miriam; Ohme, Julia; Thomson, Amanda; Humphreys, Ian R.; Ager, Ann

2016-01-01

Summary Cytotoxic CD8+ T lymphocytes play a critical role in the host response to infection by viruses. The ability to secrete cytotoxic chemicals and cytokines is considered pivotal for eliminating virus. Of equal importance is how effector CD8+ T cells home to virus-infected tissues. L-selectin has not been considered important for effector T cell homing, because levels are low on activated T cells. We report here that, although L-selectin expression is downregulated following T cell priming in lymph nodes, L-selectin is re-expressed on activated CD8+ T cells entering the bloodstream, and recruitment of activated CD8+ T cells from the bloodstream into virus-infected tissues is L-selectin dependent. Furthermore, L-selectin on effector CD8+ T cells confers protective immunity to two evolutionally distinct viruses, vaccinia and influenza, which infect mucosal and visceral organs, respectively. These results connect homing and a function of virus-specific CD8+ T cells to a single molecule, L-selectin. PMID:26804910

Open Reading Frame S/L of Varicella-Zoster Virus Encodes a Cytoplasmic Protein Expressed in Infected Cells

PubMed Central

Kemble, George W.; Annunziato, Paula; Lungu, Octavian; Winter, Ruth E.; Cha, Tai-An; Silverstein, Saul J.; Spaete, Richard R.

2000-01-01

We report the discovery of a novel gene in the varicella-zoster virus (VZV) genome, designated open reading frame (ORF) S/L. This gene, located at the left end of the prototype VZV genome isomer, expresses a polyadenylated mRNA containing a splice within the 3′ untranslated region in virus-infected cells. Sequence analysis reveals significant differences between the ORF S/Ls of wild-type and attenuated strains of VZV. Antisera raised to a bacterially expressed portion of ORF S/L reacted specifically with a 21-kDa protein synthesized in cells infected with a VZV clinical isolate and with the original vaccine strain of VZV (Oka-ATCC). Cells infected with other VZV strains, including a wild-type strain that has been extensively passaged in tissue culture and commercially produced vaccine strains of Oka, synthesize a family of proteins ranging in size from 21 to 30 kDa that react with the anti-ORF S/L antiserum. MeWO cells infected with recombinant VZV harboring mutations in the C-terminal region of the ORF S/L gene lost adherence to the stratum and adjacent cells, resulting in an altered plaque morphology. Immunohistochemical analysis of VZV-infected cells demonstrated that ORF S/L protein localizes to the cytoplasm. ORF S/L protein was present in skin lesions of individuals with primary or reactivated infection and in the neurons of a dorsal root ganglion during virus reactivation. PMID:11070031

Infection of autoreactive B lymphocytes with EBV, causing chronic autoimmune diseases.

PubMed

Pender, Michael P

2003-11-01

I hypothesize that human chronic autoimmune diseases are based on infection of autoreactive B lymphocytes by Epstein-Barr virus (EBV), in the following proposed scenario. During primary infection, autoreactive B cells are infected by EBV, proliferate and become latently infected memory B cells, which are resistant to the apoptosis that occurs during normal B-cell homeostasis because they express virus-encoded anti-apoptotic molecules. Genetic susceptibility to the effects of B-cell infection by EBV leads to an increased number of latently infected autoreactive memory B cells, which lodge in organs where their target antigen is expressed, and act there as antigen-presenting cells. When CD4(+) T cells that recognize antigens within the target organ are activated in lymphoid organs by cross-reactivity with infectious agents, they migrate to the target organ but fail to undergo activation-induced apoptosis because they receive a co-stimulatory survival signal from the infected B cells. The autoreactive T cells proliferate and produce cytokines, which recruit other inflammatory cells, with resultant target organ damage and chronic autoimmune disease.

Reversible Reprogramming of Circulating Memory T Follicular Helper Cell Function during Chronic HIV Infection

PubMed Central

Cubas, Rafael; van Grevenynghe, Julien; Wills, Saintedym; Kardava, Lela; Santich, Brian H.; Buckner, Clarisa M.; Muir, Roshell; Tardif, Virginie; Nichols, Carmen; Procopio, Francesco; He, Zhong; Metcalf, Talibah; Ghneim, Khader; Locci, Michela; Ancuta, Petronella; Routy, Jean-Pierre; Trautmann, Lydie; Li, Yuxing; McDermott, Adrian B.; Koup, Rick A.; Petrovas, Constantinos; Migueles, Steven A.; Connors, Mark; Tomaras, Georgia D.; Moir, Susan; Crotty, Shane

2015-01-01

Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2–responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART. PMID:26546609

Natural Killer Cell Function and Dysfunction in Hepatitis C Virus Infection

PubMed Central

Holder, Kayla A.; Russell, Rodney S.; Grant, Michael D.

2014-01-01

Viruses must continually adapt against dynamic innate and adaptive responses of the host immune system to establish chronic infection. Only a small minority (~20%) of those exposed to hepatitis C virus (HCV) spontaneously clear infection, leaving approximately 200 million people worldwide chronically infected with HCV. A number of recent research studies suggest that establishment and maintenance of chronic HCV infection involve natural killer (NK) cell dysfunction. This relationship is illustrated in vitro by disruption of typical NK cell responses including both cell-mediated cytotoxicity and cytokine production. Expression of a number of activating NK cell receptors in vivo is also affected in chronic HCV infection. Thus, direct in vivo and in vitro evidence of compromised NK function in chronic HCV infection in conjunction with significant epidemiological associations between the outcome of HCV infection and certain combinations of NK cell regulatory receptor and class I human histocompatibility linked antigen (HLA) genotypes indicate that NK cells are important in the immune response against HCV infection. In this review, we highlight evidence suggesting that selective impairment of NK cell activity is related to establishment of chronic HCV infection. PMID:25057504

L Particles Transmit Viral Proteins from Herpes Simplex Virus 1-Infected Mature Dendritic Cells to Uninfected Bystander Cells, Inducing CD83 Downmodulation.

PubMed

Heilingloh, Christiane S; Kummer, Mirko; Mühl-Zürbes, Petra; Drassner, Christina; Daniel, Christoph; Klewer, Monika; Steinkasserer, Alexander

2015-11-01

Mature dendritic cells (mDCs) are known as the most potent antigen-presenting cells (APCs) since they are also able to prime/induce naive T cells. Thus, mDCs play a pivotal role during the induction of antiviral immune responses. Remarkably, the cell surface molecule CD83, which was shown to have costimulatory properties, is targeted by herpes simplex virus 1 (HSV-1) for viral immune escape. Infection of mDCs with HSV-1 results in downmodulation of CD83, resulting in reduced T cell stimulation. In this study, we report that not only infected mDCs but also uninfected bystander cells in an infected culture show a significant CD83 reduction. We demonstrate that this effect is independent of phagocytosis and transmissible from infected to uninfected mDCs. The presence of specific viral proteins found in these uninfected bystander cells led to the hypothesis that viral proteins are transferred from infected to uninfected cells via L particles. These L particles are generated during lytic replication in parallel with full virions, called H particles. L particles contain viral proteins but lack the viral capsid and DNA. Therefore, these particles are not infectious but are able to transfer several viral proteins. Incubation of mDCs with L particles indeed reduced CD83 expression on uninfected bystander DCs, providing for the first time evidence that functional viral proteins are transmitted via L particles from infected mDCs to uninfected bystander cells, thereby inducing CD83 downmodulation. HSV-1 has evolved a number of strategies to evade the host's immune system. Among others, HSV-1 infection of mDCs results in an inhibited T cell activation caused by degradation of CD83. Interestingly, CD83 is lost not only from HSV-1-infected mDCs but also from uninfected bystander cells. The release of so-called L particles, which contain several viral proteins but lack capsid and DNA, during infection is a common phenomenon observed among several viruses, such as human

Therapeutic PD-L1 and LAG-3 blockade rapidly clears established blood-stage Plasmodium infection

PubMed Central

Butler, Noah S.; Moebius, Jacqueline; Pewe, Lecia L.; Traore, Boubacar; Doumbo, Ogobara K.; Tygrett, Lorraine T.; Waldschmidt, Thomas J.; Crompton, Peter D.; Harty, John T.

2011-01-01

Plasmodium infection of erythrocytes induces clinical malaria. Parasite-specific CD4+ T cells correlate with reduced parasite burdens and severity of human malaria, and are required to control blood-stage infection in mice. However, the characteristics of CD4+ T cells that determine protection or parasite persistence remain unknown. Here we show that P. falciparum infection of humans increased expression of an inhibitory receptor (PD-1) associated with T cell dysfunction. In vivo blockade of PD-L1 and LAG-3 restored CD4+ T cell function, amplified T follicular helper cell and germinal center B cell and plasmablast numbers, enhanced protective antibodies and rapidly cleared blood-stage malaria in mice. Thus, chronic malaria drives specific T cell dysfunction, which can be rescued to enhance parasite control using inhibitory therapies. PMID:22157630

Interaction of cellular proteins with BCL-xL targeted to cytoplasmic inclusion bodies in adenovirus infected cells.

PubMed

Subramanian, T; Vijayalingam, S; Kuppuswamy, M; Chinnadurai, G

2015-09-01

Adenovirus-mediated apoptosis was suppressed when cellular anti-apoptosis proteins (BCL-2 and BCL-xL) were substituted for the viral E1B-19K. For unbiased proteomic analysis of proteins targeted by BCL-xL in adenovirus-infected cells and to visualize the interactions with target proteins, BCL-xL was targeted to cytosolic inclusion bodies utilizing the orthoreovirus µNS protein sequences. The chimeric protein was localized in non-canonical cytosolic factory-like sites and promoted survival of virus-infected cells. The BCL-xL-associated proteins were isolated from the cytosolic inclusion bodies in adenovirus-infected cells and analyzed by LC-MS. These proteins included BAX, BAK, BID, BIK and BIM as well as mitochondrial proteins such as prohibitin 2, ATP synthase and DNA-PKcs. Our studies suggested that in addition to the interaction with various pro-apoptotic proteins, the association with certain mitochondrial proteins such as DNA-PKcs and prohibitins might augment the survival function of BCL-xL in virus infected cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Inferring Viral Dynamics in Chronically HCV Infected Patients from the Spatial Distribution of Infected Hepatocytes

DOE PAGES

Graw, Frederik; Balagopal, Ashwin; Kandathil, Abraham J.; ...

2014-11-13

Chronic liver infection by hepatitis C virus (HCV) is a major public health concern. Despite partly successful treatment options, several aspects of intrahepatic HCV infection dynamics are still poorly understood, including the preferred mode of viral propagation, as well as the proportion of infected hepatocytes. Answers to these questions have important implications for the development of therapeutic interventions. In this study, we present methods to analyze the spatial distribution of infected hepatocytes obtained by single cell laser capture microdissection from liver biopsy samples of patients chronically infected with HCV. By characterizing the internal structure of clusters of infected cells, wemore » are able to evaluate hypotheses about intrahepatic infection dynamics. We found that individual clusters on biopsy samples range in size from 4-50 infected cells. In addition, the HCV RNA content in a cluster declines from the cell that presumably founded the cluster to cells at the maximal cluster extension. These observations support the idea that HCV infection in the liver is seeded randomly (e.g. from the blood) and then spreads locally. Assuming that the amount of intracellular HCV RNA is a proxy for how long a cell has been infected, we estimate based on models of intracellular HCV RNA replication and accumulation that cells in clusters have been infected on average for less than a week. Further, we do not find a relationship between the cluster size and the estimated cluster expansion time. Lastly, our method represents a novel approach to make inferences about infection dynamics in solid tissues from static spatial data.« less

Inferring Viral Dynamics in Chronically HCV Infected Patients from the Spatial Distribution of Infected Hepatocytes

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

Graw, Frederik; Balagopal, Ashwin; Kandathil, Abraham J.

Chronic liver infection by hepatitis C virus (HCV) is a major public health concern. Despite partly successful treatment options, several aspects of intrahepatic HCV infection dynamics are still poorly understood, including the preferred mode of viral propagation, as well as the proportion of infected hepatocytes. Answers to these questions have important implications for the development of therapeutic interventions. In this study, we present methods to analyze the spatial distribution of infected hepatocytes obtained by single cell laser capture microdissection from liver biopsy samples of patients chronically infected with HCV. By characterizing the internal structure of clusters of infected cells, wemore » are able to evaluate hypotheses about intrahepatic infection dynamics. We found that individual clusters on biopsy samples range in size from 4-50 infected cells. In addition, the HCV RNA content in a cluster declines from the cell that presumably founded the cluster to cells at the maximal cluster extension. These observations support the idea that HCV infection in the liver is seeded randomly (e.g. from the blood) and then spreads locally. Assuming that the amount of intracellular HCV RNA is a proxy for how long a cell has been infected, we estimate based on models of intracellular HCV RNA replication and accumulation that cells in clusters have been infected on average for less than a week. Further, we do not find a relationship between the cluster size and the estimated cluster expansion time. Lastly, our method represents a novel approach to make inferences about infection dynamics in solid tissues from static spatial data.« less

IL-21 augments NK effector functions in chronically HIV-infected individuals

PubMed Central

Strbo, Natasa; de Armas, Lesley; Liu, Huanliang; Kolber, Michael A.; Lichtenheld, Mathias; Pahwa, Savita

2009-01-01

Objective This study addresses the interleukin (IL)-21 effects on resting peripheral blood NK cells in chronically HIV-infected individuals. Design The effects of IL-21 on perforin expression, proliferation, degranulation, IFN-γ production, cytotoxicity and induction of STAT phosphorylation in NK cells were determined in vitro. Methods Peripheral blood mononuclear cells from HIV-infected and healthy individuals were incubated in vitro for 6h, 24h or 5 days with IL-21 or IL-15. Percentages of perforin, IFN-γ, CD107a, NKG2D and STAT3-5 positive cells were determined within NK cell populations. K562 cells were used as target cells in NK cytotoxicity assay. Results Frequency of CD56dim cells in chronically HIV-infected individuals was diminished. Perforin expression in CD56dim and CD56bright was comparable in healthy and HIV-infected individuals. IL-15 up-regulated perforin expression primarily in CD56bright NK cells while IL-21 up-regulated perforin in both NK subsets. IL-21 and IL- 15 up-regulated CD107a and IFN-γ as well as NK cytotoxicity. IL-15 predominantly activated STAT5, while IL-21 activated STAT5 and STAT3. IL-15, but not IL-21 increased NK cell proliferation in uninfected and HIV-infected individuals. Conclusion IL-21 augments NK effector functions in chronically HIV-infected individuals and due to its perforin enhancing properties it has potential for immunotherapy or as a vaccine adjuvant. PMID:18670213

[Significance of detecting the EBV-DNA level in peripheral blood mononuclear cells and the EBV-infected cell type in patients with chronic active EBV infection].

PubMed

Xing, Yan; Song, Hong-mei; Wu, Xiao-yan; Wang, Wei; Wei, Min

2011-07-01

To study the difference in the EBV-DNA level in peripheral blood mononuclear cells (PBMC) and the type of Epstein-Barr virus (EBV)-infected cells in pediatric patients with chronic active EBV (CAEBV) infection, acute EBV infection (AEBV) and healthy children, and to analyze the relationship between the above difference and the clinical manifestation of CAEBV. Real-time fluorescent quantitative polymerase chain reaction (PCR) was used to detect the EBV-DNA levels in peripheral blood mononuclear cells (PBMC) in 12 normal children, 10 pediatric patients with CAEBV infection and 13 pediatric patients with AEBV infection in our hospital between March 2004 and April 2008. Immunomagnetic bead cell fractionation and fluorescent in situ hybridization (FISH) by EBV encoding RNA-1 ( EBER-1) probe were used in the healthy children, EBV-DNA positive CAEBV patients and AEBV patients to detect the type of EBV-infected cells. The average EBV-DNA level in CAEBV patients' PBMC was (6.8 x 10(7) +/- 1.1 x 10(8)) copies/ml, while the average EBV-DNA level of AEBV patients' PBMC was (1.3 x 10(6) +/- 1.6 x 10(6)) copies/ml. The average EBV-DNA level of CAEBV infected patients' PBMC was significantly higher than that of AEBV infected patients' PBMC (P<0.01). The cell fractionation and FISH in seven CAEBV patients showed that EBV in CAEBV patients infected not only B cells, but NK cells and CD4+ and CD8+ T cells to different degree, and these patients presented recurrent and persistent infectious mononucleosis (IM)-like symptoms. In 6 CAEBV patients infection mainly occurred to T cells, in one case, infection occurred mainly in CD8+ T cells, and the patient died from fulminant and deadly T lymphocytes proliferative syndrome except presenting firstly high fever, enlargment of the liver, spleen, lymphnode and the severe decrease of one or three kinds of blood cells. In 1 CAEBV patient the infection was mainly found in NK cells, who presented with hypersensitivity to mosquito biting and high

Phenotypic and functional analysis of CD1a+ dendritic cells from cats chronically infected with feline immunodeficiency virus.

PubMed

Zhang, Lin; Reckling, Stacie; Dean, Gregg A

2015-10-01

Numerous studies suggest dendritic cell (DC) dysfunction is central to the dysregulated immune response during HIV infection; however, in vivo studies are lacking. In the present study we used feline immunodeficiency virus (FIV) infection of cats as a model for HIV-1 infection to assess the maturation and function of dendritic cells, in vivo and in vitro. We compared CD1a+ DC migration, surface phenotype, endocytosis, mixed leukocyte reaction (MLR) and regulatory T cell (Treg) phenotype induction by CD1a+ cells isolated from lymph nodes of FIV-infected and control cats. Results showed that resident CD1a+ DC in lymph nodes of chronically FIV-infected cats are phenotypically mature, can stimulate normal primary T cell proliferation, override Treg suppression and do not skew toward Treg induction. In contrast, FIV infection had deleterious effects on antigen presentation and migratory capacity of CD1a+ cells in tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

Persistent Simian Immunodeficiency Virus Infection Causes Ultimate Depletion of Follicular Th Cells in AIDS.

PubMed

Xu, Huanbin; Wang, Xiaolei; Malam, Naomi; Lackner, Andrew A; Veazey, Ronald S

2015-11-01

CD4(+) T follicular helper (Tfh) cells are critical for the generation of humoral immune responses to pathogenic infections, providing help for B cell development, survival, and affinity maturation of Abs. Although CD4(+) Tfh cells are reported to accumulate in HIV or SIV infection, we found that germinal center Tfh cells, defined in this study as CXCR5(+)PD-1(HIGH)CD4(+) T cells, did not consistently accumulate in chronically SIV-infected rhesus macaques compared with those infected with less pathogenic simian HIV, vaccinated and SIVmac-challenged, or SIVmac-infected Mamu-A*01(+) macaques, all of which are associated with some control of virus replication and slower disease progression. Interestingly, CXCR5(+)PD-1(HIGH) Tfh cells in lymphoid tissues were eventually depleted in macaques with AIDS compared with the other cohorts. Chronic activation and proliferation of CXCR5(+)PD-1(HIGH) Tfh were increased, but PD-L2 expression was downregulated on B cells, possibly resulting in germinal center Tfh cell apoptosis. Together, these findings suggest that changes in CXCR5(+)PD-1(HIGH) Tfh cells in lymph nodes correlate with immune control during infection, and their loss or dysregulation contribute to impairment of B cell responses and progression to AIDS. Copyright © 2015 by The American Association of Immunologists, Inc.

Timing and magnitude of type I interferon responses by distinct sensors impact CD8 T cell exhaustion and chronic viral infection

PubMed Central

Wang, Yaming; Swiecki, Melissa; Cella, Marina; Alber, Gottfried; Schreiber, Robert D; Gilfillan, Susan; Colonna, Marco

2013-01-01

Summary Type I Interferons (IFN-I) promote antiviral CD8+T cell responses, but the contribution of different IFN-I sources and signaling pathways are ill-defined. While plasmacytoid dendritic cells (pDCs) produce IFN-I upon TLR stimulation, IFN-I are induced in most cells by helicases like MDA5. Using acute and chronic lymphocytic choriomeningitis virus (LCMV) infection models, we determined that pDCs transiently produce IFN-I that minimally impacts CD8+T cell responses and viral persistence. Rather, MDA5 is the key sensor that induces IFN-I required for CD8+T cell responses. In the absence of MDA5, CD8+T cell responses to acute infection rely on CD4+T cell help, and loss of both CD4+T cells and MDA5 results in CD8+T cell exhaustion and persistent infection. Chronic LCMV infection rapidly attenuates IFN-I responses, but early administration of exogenous IFN-I rescues CD8+T cells, promoting viral clearance. Thus, effective antiviral CD8+T cell responses depend on the timing and magnitude of IFN-I responses. PMID:22704623

Timing and magnitude of type I interferon responses by distinct sensors impact CD8 T cell exhaustion and chronic viral infection.

PubMed

Wang, Yaming; Swiecki, Melissa; Cella, Marina; Alber, Gottfried; Schreiber, Robert D; Gilfillan, Susan; Colonna, Marco

2012-06-14

Type I interferon (IFN-I) promotes antiviral CD8(+)T cell responses, but the contribution of different IFN-I sources and signaling pathways are ill defined. While plasmacytoid dendritic cells (pDCs) produce IFN-I upon TLR stimulation, IFN-I is induced in most cells by helicases like MDA5. Using acute and chronic lymphocytic choriomeningitis virus (LCMV) infection models, we determined that pDCs transiently produce IFN-I that minimally impacts CD8(+)T cell responses and viral persistence. Rather, MDA5 is the key sensor that induces IFN-I required for CD8(+)T cell responses. In the absence of MDA5, CD8(+)T cell responses to acute infection rely on CD4(+)T cell help, and loss of both CD4(+)T cells and MDA5 results in CD8(+)T cell exhaustion and persistent infection. Chronic LCMV infection rapidly attenuates IFN-I responses, but early administration of exogenous IFN-I rescues CD8(+)T cells, promoting viral clearance. Thus, effective antiviral CD8(+)T cell responses depend on the timing and magnitude of IFN-I production. Copyright © 2012 Elsevier Inc. All rights reserved.

Chronic inflammation associated with hepatitis C virus infection perturbs hepatic transforming growth factor beta signaling, promoting cirrhosis and hepatocellular carcinoma.

PubMed

Matsuzaki, Koichi; Murata, Miki; Yoshida, Katsunori; Sekimoto, Go; Uemura, Yoshiko; Sakaida, Noriko; Kaibori, Masaki; Kamiyama, Yasuo; Nishizawa, Mikio; Fujisawa, Junichi; Okazaki, Kazuichi; Seki, Toshihito

2007-07-01

Many patients with chronic hepatitis caused by hepatitis C virus (HCV) infection develop liver fibrosis with high risk for hepatocellular carcinoma (HCC), but the mechanism underling this process is unclear. Conversely, transforming growth factor beta (TGF-beta) activates not only TGF-beta type I receptor (TbetaRI) but also c-Jun N-terminal kinase (JNK), which convert the mediator Smad3 into two distinctive phosphoisoforms: C-terminally phosphorylated Smad3 (pSmad3C) and linker-phosphorylated Smad3 (pSmad3L). Whereas the TbetaRI/pSmad3C pathway suppresses epithelial cell growth by upregulating p21(WAF1) transcription, JNK/pSmad3L-mediated signaling promotes extracellular matrix deposition, partly, by upregulating plasminogen activator inhibitor 1 (PAI-1). We studied the domain-specific Smad3 phosphorylation in biopsy specimens representing chronic hepatitis, cirrhosis, or HCC from 100 patients chronically infected with HCV, and correlated Smad3 phosphorylation with clinical course. As HCV-infected livers progressed from chronic hepatitis through cirrhosis to HCC, hepatocytic pSmad3L/PAI-1 increased with fibrotic stage and necroinflammatory grade, and pSmad3C/p21(WAF1) decreased. Of 14 patients with chronic hepatitis C with strong hepatocytic pSmad3L positivity, 8 developed HCC within 12 years; only 1 of 12 showing little pSmad3L positivity developed HCC. We further sought molecular mechanisms in vitro. JNK activation by the pro-inflammatory cytokine interleukin-1beta stimulated the pSmad3L/PAI-1 pathway in facilitating hepatocytic invasion, in the meantime reducing TGF-beta-dependent tumor-suppressive activity by the pSmad3C/p21(WAF1) pathway. These results indicate that chronic inflammation associated with HCV infection shifts hepatocytic TGF-beta signaling from tumor-suppression to fibrogenesis, accelerating liver fibrosis and increasing risk for HCC.

CD8+ T cells of chronic HCV-infected patients express multiple negative immune checkpoints following stimulation with HCV peptides.

PubMed

Barathan, Muttiah; Mohamed, Rosmawati; Vadivelu, Jamuna; Chang, Li Yen; Vignesh, Ramachandran; Krishnan, Jayalakshmi; Sigamani, Panneer; Saeidi, Alireza; Ram, M Ravishankar; Velu, Vijayakumar; Larsson, Marie; Shankar, Esaki M

2017-03-01

Hepatitis C virus (HCV)-specific CD4+ and CD8+ T cells are key to successful viral clearance in HCV disease. Accumulation of exhausted HCV-specific T cells during chronic infection results in considerable loss of protective functional immune responses. The role of T-cell exhaustion in chronic HCV disease remains poorly understood. Here, we studied the frequency of HCV peptide-stimulated T cells expressing negative immune checkpoints (PD-1, CTLA-4, TRAIL, TIM-3 and BTLA) by flow cytometry, and measured the levels of Th1/Th2/Th17 cytokines secreted by T cells by a commercial Multi-Analyte ELISArray™ following in vitro stimulation of T cells using HCV peptides and phytohemagglutinin (PHA). HCV peptide-stimulated CD4+ and CD8+ T cells of chronic HCV (CHC) patients showed significant increase of CTLA-4. Furthermore, HCV peptide-stimulated CD4+ T cells of CHC patients also displayed relatively higher levels of PD-1 and TRAIL, whereas TIM-3 was up-regulated on HCV peptide-stimulated CD8+ T cells. Whereas the levels of IL-10 and TGF-β1 were significantly increased, the levels of pro-inflammatory cytokines IL-2, TNF-α, IL-17A and IL-6 were markedly decreased in the T cell cultures of CHC patients. Chronic HCV infection results in functional exhaustion of CD4+ and CD8+ T cells likely contributing to viral persistence. Copyright © 2016 Elsevier Inc. All rights reserved.

Invariant NKT cells from HIV-1 or Mycobacterium tuberculosis-infected patients express an activated phenotype.

PubMed

Montoya, Carlos J; Cataño, Juan C; Ramirez, Zoraida; Rugeles, Maria T; Wilson, S Brian; Landay, Alan L

2008-04-01

The frequency, subsets and activation status of peripheral blood invariant NKT (iNKT) cells were evaluated in pulmonary tuberculosis (TB) patients and in chronically HIV-1-infected subjects. The absolute numbers of iNKT cells were significantly decreased in TB patients and in HIV-1+ individuals who were antiretroviral therapy naive or had detectable viremia despite receiving HAART. iNKT cell subset analysis demonstrated a decreased percentage of CD4(+) iNKT cells in HIV-1+ subjects, and a decreased percentage of double negative iNKT cells in TB patients. Peripheral blood iNKT cells from HIV-1+ and TB patients had significantly increased expression of CD69, CD38, HLA-DR, CD16, CD56, and CD62L. The expression of CD25 was significantly increased only on iNKT cells from TB patients. These findings indicate that peripheral blood iNKT cells in these two chronic infections show an up-regulated expression of activation markers, suggesting their role in the immune response to infection.

Infection of nonphagocytic host cells by legionella.

PubMed

Day, Shandra R; Sifri, Costi D; Hoffman, Paul S

2013-01-01

Legionella pneumophila is an intracellular pathogen of free-living protozoa that can also infect alveolar macrophages, L929 fibroblast cells, and HeLa cells. Infection of nonphagocytic cells by L. pneumophila can be used to study invasion mechanisms, compare infectivity of different strains and identify factors important for virulence. Virulent strains of L. pneumophila exposed to monolayers of L929 cells are able to invade and form virus-like plaques, which can be enumerated as a measure of infectivity. Invasiveness of HeLa cells can also be used to evaluate relative infectivity and to study mechanisms of invasion and to track the development of cyst-like forms. The detailed methods of both the L929 plaque assay and HeLa cell invasion assay are described.

Characteristics of Infection Immunity Regulated by Toxoplasma gondii to Maintain Chronic Infection in the Brain

PubMed Central

Hwang, Young Sang; Shin, Ji-Hun; Yang, Jung-Pyo; Jung, Bong-Kwang; Lee, Sang Hyung; Shin, Eun-Hee

2018-01-01

To examine the immune environment of chronic Toxoplasma gondii infection in the brain, the characteristics of infection-immunity (premunition) in infection with T. gondii strain ME49 were investigated for 12 weeks postinfection (PI). The results showed that neuronal cell death, microglia infiltration and activation, inflammatory and anti-inflammatory cytokine expression, Stat1 phosphorylation, and microglia activation and inflammatory gene transcripts related to M1 polarization in the brain were increased during the acute infection (AI) stage (within 6 weeks PI), suggesting that innate and cellular inflammatory response activation and neurodegeneration contributed to excessive inflammatory responses. However, these immune responses decreased during the chronic infection (CI) stage (over 6 weeks PI) with reductions in phosphorylated STAT1 (pSTAT1) and eosinophilic neurons. Notably, increases were observed in transcripts of T-cell exhaustion markers (TIM3, LAG3, KLRG1, etc.), suppressor of cytokines signaling 1 protein (SOCS1), inhibitory checkpoint molecules (PD-1 and PD-L1), and Arg1 from the AI stage (3 weeks PI), implying active immune intervention under the immune environment of M1 polarization of microglia and increases in inflammatory cytokine levels. However, when BV-2 microglia were stimulated with T. gondii lysate antigens (strain RH or ME49) in vitro, nitrite production increased and urea production decreased. Furthermore, when BV-2 cells were infected by T. gondii tachyzoites (strain RH or ME49) in vitro, nitric oxide synthase and COX-2 levels decreased, whereas Arg1 levels significantly increased. Moreover, Arg1 expression was higher in ME49 infection than in RH infection, whereas nitrite production was lower in ME49 infection than in RH infection. Accordingly, these results strongly suggest that immune triggering of T. gondii antigens induces M1 polarization and activation of microglia as well as increase NO production, whereas T. gondii

HIV-1 Nef and Vpu Interfere with L-Selectin (CD62L) Cell Surface Expression To Inhibit Adhesion and Signaling in Infected CD4+ T Lymphocytes

PubMed Central

Vassena, Lia; Giuliani, Erica; Koppensteiner, Herwig; Bolduan, Sebastian; Schindler, Michael

2015-01-01

ABSTRACT Leukocyte recirculation between blood and lymphoid tissues is required for the generation and maintenance of immune responses against pathogens and is crucially controlled by the L-selectin (CD62L) leukocyte homing receptor. CD62L has adhesion and signaling functions and initiates the capture and rolling on the vascular endothelium of cells entering peripheral lymph nodes. This study reveals that CD62L is strongly downregulated on primary CD4+ T lymphocytes upon infection with human immunodeficiency virus type 1 (HIV-1). Reduced cell surface CD62L expression was attributable to the Nef and Vpu viral proteins and not due to increased shedding via matrix metalloproteases. Both Nef and Vpu associated with and sequestered CD62L in perinuclear compartments, thereby impeding CD62L transport to the plasma membrane. In addition, Nef decreased total CD62L protein levels. Importantly, infection with wild-type, but not Nef- and Vpu-deficient, HIV-1 inhibited the capacity of primary CD4+ T lymphocytes to adhere to immobilized fibronectin in response to CD62L ligation. Moreover, HIV-1 infection impaired the signaling pathways and costimulatory signals triggered in primary CD4+ T cells by CD62L ligation. We propose that HIV-1 dysregulates CD62L expression to interfere with the trafficking and activation of infected T cells. Altogether, this novel HIV-1 function could contribute to virus dissemination and evasion of host immune responses. IMPORTANCE L-selectin (CD62L) is an adhesion molecule that mediates the first steps of leukocyte homing to peripheral lymph nodes, thus crucially controlling the initiation and maintenance of immune responses to pathogens. Here, we report that CD62L is downmodulated on the surfaces of HIV-1-infected T cells through the activities of two viral proteins, Nef and Vpu, that prevent newly synthesized CD62L molecules from reaching the plasma membrane. We provide evidence that CD62L downregulation on HIV-1-infected primary T cells results in

The impact of ethanol extract of propolis on biofilm forming by Proteus Mirabilis strains isolated from chronic wounds infections.

PubMed

Kwiecińska-Piróg, Joanna; Skowron, Krzysztof; Śniegowska, Agata; Przekwas, Jana; Balcerek, Maciej; Załuski, Daniel; Gospodarek-Komkowska, Eugenia

2018-05-04

Alcoholic propolis extracts may be used to eliminate microbes in mucous membranes and skin inflammations and in wound infections. The aim of this study was an assessment of the ethanol extract of propolis (EEP) activity against biofilm formation by P. mirabilis. Six clinical strains of P. mirabilis isolated from patients with chronic wound infection, and one reference strain of P. mirabilis ATCC 29906 were used. Biofilm was formed in 96-well plate. In order to evaluate the effect of EEP at a concentration range of 1.56-100 mg/mL on the forming and mature biofilm, P. mirabilis cells were released by sonication. In this study the effectiveness of 25-100 mg/mL of EEP on the forming P. mirabilis biofilm and concentrations of 25-50 mg/mL of EEP on formed biofilm has been demonstrated. Our results suggest the possibility of using the EEP in treatment of chronic wound infection caused by P. mirabilis.

Methamphetamine mediates immune dysregulation in a murine model of chronic viral infection

PubMed Central

Sriram, Uma; Haldar, Bijayesh; Cenna, Jonathan M.; Gofman, Larisa; Potula, Raghava

2015-01-01

Methamphetamine (METH) is a highly addictive psychostimulant that not only affects the brain and cognitive functions but also greatly impacts the host immune system, rendering the body susceptible to infections and exacerbating the severity of disease. Although there is gathering evidence about METH abuse and increased incidence of HIV and other viral infections, not much is known about the effects on the immune system in a chronic viral infection setting. We have used the lymphocytic choriomeningitis virus (LCMV) chronic mouse model of viral infection in a chronic METH environment and demonstrate that METH significantly increases CD3 marker on splenocytes and programmed death-1 (PD-1) expression on T cells, a cell surface signaling molecule known to inhibit T cell function and cause exhaustion in a lymphoid organ. Many of these METH effects were more pronounced during early stage of infection, which are gradually attenuated during later stages of infection. An essential cytokine for T-lymphocyte homeostasis, Interleukin-2 (IL-2) in serum was prominently reduced in METH-exposed infected mice. In addition, the serum pro-inflammatory (TNF, IL12 p70, IL1β, IL-6, and KC-GRO) and Th2 (IL-2, IL-10, and IL-4) cytokine profiles were also altered in the presence of METH. Interestingly CXCR3, an inflammatory chemokine receptor, showed significant increase in the METH treated LCMV infected mice. Similarly, compared to only infected mice, epidermal growth factor receptor (EGFR) in METH exposed LCMV infected mice were up regulated. Collectively, our data suggest that METH alters systemic, peripheral immune responses and modulates key markers on T cells involved in pathogenesis of chronic viral infection. PMID:26322025

B cell-intrinsic TLR7 signaling is required for optimal B cell responses during chronic viral infection

PubMed Central

Clingan, Jonathan M.; Matloubian, Mehrdad

2013-01-01

The importance for activation of innate immunity by pattern recognition receptors in forming an effective adaptive immune response is well known. Toll-like receptors (TLRs) have been demonstrated to be critical for antibody responses to a variety of immunizations. In particular, recent evidence suggests that B cell-intrinsic TLR signaling is required for optimal responses to virus-like antigens, but mechanisms by which TLR signaling impacts antibody responses during infection in vivo is unclear. In the present study, we demonstrate that deficiency of TLR7 in B cells alone is sufficient to significantly impact antibody responses in mice during chronic viral infection. This effect was independent of T follicular helper cells, and resulted in a loss of plasma cells generated later, but not early, in the response. The defect in plasma cell formation appeared to be secondary to a qualitative effect of TLR signaling on the germinal center (GC) B cell response. GC B cells in TLR7-deficient mice proliferated to a lesser extent and had a greater proportion of cells with phenotypic characteristics of light zone, relative to dark zone GC B cells. These results suggest that B cell-intrinsic TLR signaling in vivo likely affects plasma cell output by altered selection of antigen-specific B cells in the germinal center. PMID:23761632

Safety and efficacy of anti-PD-L1 therapy in the woodchuck model of HBV infection

PubMed Central

Balsitis, Scott; Gali, Volodymyr; Mason, Pamela J.; Chaniewski, Susan; Levine, Steven M.; Wichroski, Michael J.; Feulner, Michael; Song, Yunling; Granaldi, Karen; Loy, James K.; Thompson, Chris M.; Lesniak, Jacob A.; Brockus, Catherine; Kishnani, Narendra; Menne, Stephan; Cockett, Mark I.; Iyer, Renuka; Mason, Stephen W.

2018-01-01

Immune clearance of Hepatitis B virus (HBV) is characterized by broad and robust antiviral T cell responses, while virus-specific T cells in chronic hepatitis B (CHB) are rare and exhibit immune exhaustion that includes programmed-death-1 (PD-1) expression on virus-specific T cells. Thus, an immunotherapy able to expand and activate virus-specific T cells may have therapeutic benefit for CHB patients. Like HBV-infected patients, woodchucks infected with woodchuck hepatitis virus (WHV) can have increased hepatic expression of PD-1-ligand-1 (PD-L1), increased PD-1 on CD8+ T cells, and a limited number of virus-specific T cells with substantial individual variation in these parameters. We used woodchucks infected with WHV to assess the safety and efficacy of anti-PD-L1 monoclonal antibody therapy (αPD-L1) in a variety of WHV infection states. Experimentally-infected animals lacked PD-1 or PD-L1 upregulation compared to uninfected controls, and accordingly, αPD-L1 treatment in lab-infected animals had limited antiviral effects. In contrast, animals with naturally acquired WHV infections displayed elevated PD-1 and PD-L1. In these same animals, combination therapy with αPD-L1 and entecavir (ETV) improved control of viremia and antigenemia compared to ETV treatment alone, but with efficacy restricted to a minority of animals. Pre-treatment WHV surface antigen (sAg) level was identified as a statistically significant predictor of treatment response, while PD-1 expression on peripheral CD8+ T cells, T cell production of interferon gamma (IFN-γ) upon in vitro antigen stimulation (WHV ELISPOT), and circulating levels of liver enzymes were not. To further assess the safety of this strategy, αPD-L1 was tested in acute WHV infection to model the risk of liver damage when the extent of hepatic infection and antiviral immune responses were expected to be the greatest. No significant increase in serum markers of hepatic injury was observed over those in infected, untreated

Current research on chronic active Epstein-Barr virus infection in Japan.

PubMed

Fujiwara, Shigeyoshi; Kimura, Hiroshi; Imadome, Ken-ichi; Arai, Ayako; Kodama, Eiichi; Morio, Tomohiro; Shimizu, Norio; Wakiguchi, Hiroshi

2014-04-01

Epstein-Barr virus (EBV) infection is usually asymptomatic and persists lifelong. Although EBV-infected B cells have the potential for unlimited proliferation, they are effectively removed by the virus-specific cytotoxic T cells, and EBV-associated lymphoproliferative disease develops only in immunocompromised hosts. Rarely, however, individuals without apparent immunodeficiency develop chronic EBV infection with persistent infectious mononucleosis-like symptoms. These patients have high EBV-DNA load in the peripheral blood and systemic clonal expansion of EBV-infected T cells or natural killer (NK) cells. Their prognosis is poor with life-threatening complications including hemophagocytic lymphohistiocytosis, organ failure, and malignant lymphomas. The term "chronic active EBV infection" (CAEBV) is now generally used for this disease. The geographical distribution of CAEBV is markedly uneven and most cases have been reported from Japan and other East Asian countries. Here we summarize the current understanding of CAEBV and describe the recent progress of CAEBV research in Japan. © 2014 Japan Pediatric Society.

In-cell infection: a novel pathway for Epstein-Barr virus infection mediated by cell-in-cell structures

PubMed Central

Ni, Chao; Chen, Yuhui; Zeng, Musheng; Pei, Rongjuan; Du, Yong; Tang, Linquan; Wang, Mengyi; Hu, Yazhuo; Zhu, Hanyu; He, Meifang; Wei, Xiawei; Wang, Shan; Ning, Xiangkai; Wang, Manna; Wang, Jufang; Ma, Li; Chen, Xinwen; Sun, Qiang; Tang, Hong; Wang, Ying; Wang, Xiaoning

2015-01-01

Epstein-Barr virus (EBV) can infect both susceptible B lymphocytes and non-susceptible epithelial cells (ECs). Viral tropism analyses have revealed two intriguing means of EBV infection, either by a receptor-mediated infection of B cells or by a cell-to-cell contact-mediated infection of non-susceptible ECs. Herein, we report a novel “in-cell infection” mechanism for EBV infection of non-susceptible ECs through the formation of cell-in-cell structures. Epithelial CNE-2 cells were invaded by EBV-infected Akata B cells to form cell-in-cell structures in vitro. Such unique cellular structures could be readily observed in the specimens of nasopharyngeal carcinoma. Importantly, the formation of cell-in-cell structures led to the autonomous activation of EBV within Akata cells and subsequent viral transmission to CNE-2 cells, as evidenced by the expression of viral genes and the presence of virion particles in CNE-2 cells. Significantly, EBV generated from in-cell infected ECs displayed altered tropism with higher infection efficacy to both B cells and ECs. In addition to CNE-2 tumor cells, cell-in-cell structure formation could also mediate EBV infection of NPEC1-Bmi1 cells, an immortalized nasopharyngeal epithelial cell line. Furthermore, efficient infection by this mechanism involved the activation of the PI3K/AKT signaling pathway. Thus, our study identified “in-cell infection” as a novel mechanism for EBV infection. Given the diversity of virus-infected cells and the prevalence of cell-in-cell structures during chronic infection, we speculate that “in-cell infection” is likely a general mechanism for EBV and other viruses to infect non-susceptible ECs. PMID:25916549

A distinct subtype of Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorder: adult patients with chronic active Epstein-Barr virus infection-like features.

PubMed

Kawamoto, Keisuke; Miyoshi, Hiroaki; Suzuki, Takaharu; Kozai, Yasuji; Kato, Koji; Miyahara, Masaharu; Yujiri, Toshiaki; Choi, Ilseung; Fujimaki, Katsumichi; Muta, Tsuyoshi; Kume, Masaaki; Moriguchi, Sayaka; Tamura, Shinobu; Kato, Takeharu; Tagawa, Hiroyuki; Makiyama, Junya; Kanisawa, Yuji; Sasaki, Yuya; Kurita, Daisuke; Yamada, Kyohei; Shimono, Joji; Sone, Hirohito; Takizawa, Jun; Seto, Masao; Kimura, Hiroshi; Ohshima, Koichi

2018-06-01

The characteristics of adult patients with chronic active Epstein-Barr virus infection are poorly recognized, hindering early diagnosis and an improved prognosis. We studied 54 patients with adult-onset chronic active Epstein-Barr virus infection diagnosed between 2005 and 2015. Adult onset was defined as an estimated age of onset of 15 years or older. To characterize the clinical features of these adults, we compared them to those of 75 pediatric cases (estimated age of onset <15 years). We compared the prognosis of adult-onset chronic active Epstein-Barr virus infection with that of patients with nasal-type (n=37) and non-nasal-type (n=45) extranodal NK/T-cell lymphoma. The median estimated age of onset of these lymphomas was 39 years (range, 16-86 years). Compared to patients with pediatric-onset disease, those in whom the chronic active Epstein-Barr virus infection developed in adulthood had a significantly decreased incidence of fever ( P =0.005), but greater frequency of skin lesions ( P <0.001). Moreover, hypersensitivity to mosquito bites and the occurrence of hydroa vacciniforme were less frequent in patients with adult-onset disease ( P <0.001 and P =0.0238, respectively). Thrombocytopenia, high Epstein-Barr virus nuclear antigen antibody titer, and the presence of hemophagocytic syndrome were associated with a poor prognosis ( P =0.0087, P =0.0236, and P =0.0149, respectively). Allogeneic hematopoietic stem cell transplantation may improve survival ( P =0.0289). Compared to pediatric-onset chronic active Epstein-Barr virus infection and extranodal NK/T-cell lymphoma, adult-onset chronic active Epstein-Barr virus infection had a poorer prognosis ( P <0.001 and P =0.0484, respectively). Chronic active Epstein-Barr virus infection can develop in a wide age range, with clinical differences between adult-onset and pediatric-onset disease. Adult-onset chronic active Epstein-Barr virus infection is a disease with a poor prognosis. Further research will be

[Clinical management of acute and chronic human immunodeficiency virus infection before starting antiretroviral treatment].

PubMed

Miró, José M; Manzardo, Christian; Zamora, Laura; Pumarola, Tomas; Herreras, Zoe; Gallart, Teresa; Gatell, José M

2011-12-01

The evaluation of new cases of HIV infection is relatively common in Spain, where several thousands of patients with new infections are diagnosed each year. Eighty per cent of them have a chronic HIV infection at the first clinical evaluation, which is symptomatic (late presenters) in up to 30% of patients. The initial evaluation of HIV infection is not only directed at determining the clinical, virological (plasma HIV RNA viral load, resistance test and viral tropism) and immunological (CD4+ T-cell cell count) situation of the patients, but must also address the study of their co-infections (hepatitis, tuberculosis) and comorbidities (cardiovascular, hepatic, renal and bone) and the risk of HIV transmission. This is needed in order to decide, whether or not to start antiretroviral treatment, and with which combined antiretroviral treatment to start with, the prophylaxis of opportunistic infections, and the treatment of coinfections and comorbidities. The past and current medical history, the physical examination and laboratory tests will help us decide if the patient is to receive therapeutic intervention. The level of CD4+ T-cell lymphocytes is the best marker to suggest when to start combined antiretroviral treatment, indicating whether or not to start prophylaxis against opportunistic infections (if patients have a CD4+ T-cell count below 200 cells/mm(3)), and in advanced patients should make us suspect the presence of active opportunistic diseases in symptomatic cases. The management of patients with HIV infection must also include appropriate health education on the modes of transmission and prevention of HIV infection, and also to explain its natural history and how it can be modified with proper antiretroviral treatment, as well as to promote a healthy life. No less important is the psychological support, as these patients must learn to live with a chronic infection, which managed properly can ensure a very good long-term prognosis and quality of life

Hepatocellular apoptosis associated with cytotoxic T/natural killer-cell infiltration in chronic active EBV infection.

PubMed

Nomura, Yuko; Kimura, Hiroshi; Karube, Kennosuke; Yoshida, Shiro; Sugita, Yasuo; Niino, Daisuke; Shimizu, Kei; Kimura, Yoshizo; Aoki, Ryosuke; Kiyasu, Junichi; Takeuchi, Masanori; Hashikawa, Keiko; Hirose, Shinichi; Ohshima, Koichi

2009-07-01

The aim of the present study was to identify the mechanism of hepatocellular apoptosis induced by EBV-infected cytotoxic T/natural killer (NK) cells in chronic active EBV infection (CAEBV). Eight patients with CAEBV were studied, and infected T-cell expansion and NK-cell expansion were detected in four patients each. Biopsy or necropsy was performed on lymph node, liver, or spleen, and each specimen was subjected to immunohistochemical double staining of CD3 plus caspase-3 with the addition of cytotoxic markers of T-cell restricted intracellular antigen-1 (TIA-1), perforin, and granzyme B, as well as EBV in situ hybridization (EBV-ISH). In the liver, some of the infiltrating CD3-positive lymphocytes stained positively for EBV-ISH and cytotoxic markers. Double staining of CD3 plus caspase-3 indicated caspase-3 positive hepatocytes with apoptotic features, accompanied by extensive infiltration of CD3-positive cells, which were directly attached to the apoptotic caspase-3 positive hepatocytes. In contrast, far fewer cells stained positive for caspase-3 in lymph node and spleen than in liver. The present findings suggest that in patients with CAEBV, cytotoxic T/NK cells may directly induce hepatocytes to undergo apoptosis more frequently than they do cells in other organs of the reticulo-endothelial system.

[Characteristics of peripheral blood lymphocyte immune subsets in patients with chronic active Epstein-Barr virus infection].

PubMed

Xing, Yan; Song, Hong-mei; Li, Tai-sheng; Qiu, Zhi-feng; Wu, Xiao-yan; Wang, Wei; Wei, Min

2009-06-01

To study the characteristics of the peripheral blood lymphocyte subsets in pediatric patients with chronic active EBV (CAEBV) infection. Flow cytometry was used to detect the peripheral blood NK, B, T lymphocyte subsets and the functional, regulatory, naïve, memory and activatory subsets of T lymphocytes in 10 pediatric patients with CAEBV infection, 13 pediatric patients with acute Epstein-Barr virus infection (AEBV) and 12 healthy children in our hospital between March 2004 and April 2008. Compared with AEBV group, the number of white blood cells [3325 x 10(6)/L (median, just the same as the following)], lymphocytes (1078 x 10(6)/L), NK cells (68 x 10(6)/L), B cells (84 x 10(6)/L), total T cells (684 x 10(6)/L), CD4+ T cells (406 x 10(6)/L) and CD8+ T cells (295 x 10(6)/L) in CAEBV patients were lower (P<0.05). The functional subset of the CD4+ T cells in CAEBV group (94.5%) was lower than those of the healthy control group (98.7%) (P<0.05), but was still higher than those of AEBV group (74.0%) (P<0.05). While the functional subset of the CD8+ T cells in CAEBV (40.7%) was not dramatically different from the healthy control group (48.3%), but was still higher than that of AEBV group (21.0%) (P<0.05). Although the regulatory subset in CAEBV group (5.0%) was higher than the health control group (4.6%) (P<0.05), but lower than AEBV group (5.8%) (P<0.05). In CAEBV, the proportion of CD4+/CD8+ naïve T cells (32.3%/37.5%) was lower than that of normal group (58.3%/56.6%) (P<0.05), but the proportion of CD4+/CD8+ effective memory T cells in CAEBV group (23.9%/15.1%) was lower than that in AEBV group (36.5%/69.8%) (P<0.05), while the proportion of CD8+ fake naïve T cells in CAEBV (17.5%) was higher than the other 2 groups (P<0.05). The CD8+ activatory subset in CAEBV group (84.4%/34.0%) was higher than that of the healthy control group (44.1%/16.7%) (P<0.05), but still lower than AEBV group (96%/95%) (P<0.05). There is an imbalance in lymphocyte subsets and disturbance

Clinicopathological states of Epstein-Barr virus-associated T/NK-cell lymphoproliferative disorders (severe chronic active EBV infection) of children and young adults.

PubMed

Suzuki, Keiko; Ohshima, Koichi; Karube, Kennosuke; Suzumiya, Junji; Ohga, Shouichi; Ishihara, Shigehiko; Tamura, Kazuo; Kikuchi, Masahiro

2004-05-01

Epstein-Barr virus (EBV)-associated T/NK-cell lymphoproliferative disorders (LPD) of children and young adults are sometimes termed as severe chronic active EBV infection (CAEBV), and are associated with an aggressive clinical course. However, these clinicopathological states and the role of EBV have not been clarified. A retrospective study was performed on 43 children and adult patients, who manifested EBV-associated T/NK-cell lymphoproliferative disorders (EBV-T/NK-LPD) and most of whom had experienced general illness with CAEBV for several months or years. Clinicopathologically, 43 patients were classified into four groups: group A (smoldering state) (n=7), morphological non-neoplastic LPD with chronic clinical course (several years); group B (chronic state) (n=10), non-neoplastic LPD with clonal EBV-infected cells and a chronic course; group C (leukemia/lymphoma state) (n=22), neoplastic LPD with a subacute course (years to months); group D (fulminant state) (n=4), neoplastic LPD with a fulminant course (weeks to days). The 43 patients comprised 21 males and 22 females. The median age of group A was 14 years, group B 12 years, group C 17 years, and group D 1 year. Four of 7 patients in group A, 3 of 10 in group B, 12 of 22 in group C, and all 4 in group D have died. Causes of death included hemophagocytic syndrome and/or tumor death. Genotypically and phenotypically, group C was composed of peripheral T-cell lymphoma (PTCL), and NK-cell leukemia/lymphoma (NKLL), and group D comprised cases of PTCL. Groups A and B exhibited increased NK- or T-cells (CD8>CD4), and rare B-cells. Serologic titers of EBV were only modestly elevated or not elevated in almost all cases. EBV early RNA-1 (EBER-1)-expressing EBV-infected cells were frequently encountered in each group, but the number of infected cells varied between the cases. The EBV genotype did not differ between the groups. Our findings support an important pathogenic role for EBV-infected T/NK-cell infection

Epstein-Barr-Virus-Positive B-Cell Lymphoma of Recipient Origin Despite of the Elimination of Clonally EBV-Infected T Cells by Allogeneic Stem Cell Transplantation in a Patient with Chronic Active EBV Infection

PubMed Central

Nagasawa, Masayuki

2012-01-01

A 20-year-old patient with chronic active EBV infection (CAEBV) received peripheral blood stem cell transplantation (PBSCT) from HLA-one-locus-mismatched mother. Although EB-virus-infected T cells were eliminated after PBSCT, she developed EB-virus-positive B-cell lymphoma of recipient origin in the brain. By reducing the immunosuppressive therapy, the initial lesion disappeared. However, another lesion in the opposite lateral brain appeared later and was resistant to further reduction of immunosuppressive therapy. EBV-DNA was persistently negative after PBSCT in the peripheral blood. This case is suggestive in management of EBV reactivation after SCT and understanding alloimmune response to EBV. PMID:23213608

Natural killer cell-type body cavity lymphoma following chronic active Epstein-Barr virus infection.

PubMed

Ogata, Masao; Imamura, Tomoyuki; Mizunoe, Syunji; Ohtsuka, Eiichi; Kikuchi, Hiroshi; Nasu, Masaru

2003-06-01

We describe a 69-year-old female who developed natural killer cell-type body cavity lymphoma following chronic active Epstein-Barr virus (CAEBV) infection. Examination of the patient's pleural effusion revealed large abnormal lymphocytes, which were CD2(+), CD7(+), CD30(+), CD56(+), CD3(-), and CD4(-). No rearrangement of T cell receptor genes was detected. Clonal proliferation of Epstein-Barr virus (EBV)-infected cells in pleural effusion was demonstrated by Southern blot hybridization analysis. Human herpesvirus type-8 (HHV-8) DNA was not detected in these cells. The patient achieved a complete remission with combination chemotherapy. Prior to the clinical onset of lymphoma, high fever of unknown origin had persisted for 21 months. IgG antibodies to EBV-viral capsid antigen and to EBV-early antigens, types D and R were not high (1:160 and less than 1:10, respectively). Two months after the onset of fever, however, retrospective quantitative PCR assay revealed a high EBV DNA load in plasma, indicating that CAEBV infection had been the cause of the patient's recurrent fever. The remarkable features of this case are (i) the development of lymphoma following CAEBV infection that demonstrated a normal pattern of EBV-specific antibodies, (ii) the development of HHV-8-negative body cavity lymphoma, and (iii) the effectiveness of combination chemotherapy. Copyright 2003 Wiley-Liss, Inc.

Acute or chronic life-threatening diseases associated with Epstein-Barr virus infection.

PubMed

Okano, Motohiko; Gross, Thomas G

2012-06-01

Infectious mononucleosis (IM) is one of the representative, usually benign, acute diseases associated with primary Epstein-Barr virus (EBV) infection. IM is generally self-limiting and is characterized mostly by transient fever, lymphadenopathy and hepatosplenomegaly. However, very rarely primary EBV infection results in severe or fatal conditions such as hemophagocytic lymphohistiocytosis together with fulminant hepatitis designated as severe or fatal IM or EBV-associated hemophagocytic lymphohistiocytosis alone. In addition, chronic EBV-associated diseases include Burkitt's lymphoma, undifferentiated nasopharyngeal carcinoma, Hodgkin lymphoma, T-cell lymphoproliferative disorder (LPD)/lymphoma, natural killer-cell LPD including leukemia or lymphoma, gastric carcinoma, pyothorax-associated lymphoma and senile B-cell LPD as well as chronic active EBV infection and LPD/lymphoma in patients with immunodeficiency. The number of chronic life-threatening diseases linked to the EBV infection is increasingly reported and many of these diseases have a poor prognosis. This review will focus on the historical, pathogenetic, diagnostic, therapeutic and prophylactic issues of EBV-associated life-threatening diseases.

Dominant expression of interleukin-10 and transforming growth factor-beta genes in activated T-cells of chronic active Epstein-Barr virus infection.

PubMed

Ohga, Shouichi; Nomura, Akihiko; Takada, Hidetoshi; Tanaka, Tamami; Furuno, Kenji; Takahata, Yasushi; Kinukawa, Naoko; Fukushima, Noriyasu; Imai, Shosuke; Hara, Toshiro

2004-11-01

Chronic active Epstein-Barr virus (EBV) infection is a chronic mononucleosis syndrome associated with clonal proliferation of EBV-carrying T-/natural killer (NK)-cells. High levels of circulating EBV and activated T-cells are sustained during the prolonged disease course, whereas it is not clear how ectopic EBV infection in T-/NK-cells has been established and maintained. To assess the biological role of activated T-cells in chronic active EBV infection (CAEBV), EBV DNA and cellular gene expressions in peripheral T-cells were quantified in CAEBV and infectious mononucleosis (IM) patients. In CAEBV, HLA-DR(+) T-cells had higher viral load and larger amounts of IFN gamma, IL-10, transforming growth factor-beta (TGF beta), and cytotoxic T lymphocyte antigen-4 (CTLA4) mRNA than HLA-DR(-)T-cells. HLA-DR(+) T cells of IM patients transcribed more IFN gamma and IL-10 than their HLA-DR(-)T cells. Expression levels of IFN gamma and forkhead box p3 (Foxp3) in CAEBV HLA-DR(+) T-cells were higher than in IM HLA-DR(+) T-cells. The effective variables to discriminate the positivity of HLA-DR were IL-10, IFN gamma, CTLA4, TGF beta, and IL-2 in the order of statistical weight. EBV load in CAEBV T-cells correlated with the expression levels of only IL-10 and TGF beta. These results suggest that CAEBV T-cells are activated to transcribe IFN gamma, IL-10, and TGF beta excessively, and the latter two genes are expressed preferentially in the EBV-infected subsets. The dominant expression of regulatory cytokines in T-cells may imply a viral evasion mechanism in the disease.

Effect of treatment with cyclophosphamide in low doses upon the onset of delayed type hypersensitivity in mice chronically infected with Trypanosoma cruzi: involvement of heart interstitial dendritic cells.

PubMed

Thé, Torriceli Souza; Portella, Renata Siqueira; Guerreiro, Marcos Lázaro; Andrade, Sonia Gumes

2013-09-01

Acute infection with Trypanosoma cruzi results in intense myocarditis, which progresses to a chronic, asymptomatic indeterminate form. The evolution toward this chronic cardiac form occurs in approximately 30% of all cases of T. cruzi infection. Suppression of delayed type hypersensitivity (DTH) has been proposed as a potential explanation of the indeterminate form. We investigated the effect of cyclophosphamide (CYCL) treatment on the regulatory mechanism of DTH and the participation of heart interstitial dendritic cells (IDCs) in this process using BALB/c mice chronically infected with T. cruzi. One group was treated with CYCL (20 mg/kg body weight) for one month. A DTH skin test was performed by intradermal injection of T. cruzi antigen (3 mg/mL) in the hind-footpad and measured the skin thickness after 24 h, 48 h and 72 h. The skin test revealed increased thickness in antigen-injected footpads, which was more evident in the mice treated with CYCL than in those mice that did not receive treatment. The thickened regions were characterised by perivascular infiltrates and areas of necrosis. Intense lesions of the myocardium were present in three/16 cases and included large areas of necrosis. Morphometric evaluation of lymphocytes showed a predominance of TCD8 cells. Heart IDCs were immunolabelled with specific antibodies (CD11b and CD11c) and T. cruzi antigens were detected using a specific anti-T. cruzi antibody. Identification of T. cruzi antigens, sequestered in these cells using specific anti-T. cruzi antibodies was done, showing a significant increase in the number of these cells in treated mice. These results indicate that IDCs participate in the regulatory mechanisms of DTH response to T. cruzi infection.

In Vivo Administration of a JAK3 Inhibitor during Acute SIV Infection Leads to Significant Increases in Viral Load during Chronic Infection

PubMed Central

Takahashi, Yoshiaki; Byrareddy, Siddappa N.; Albrecht, Christina; Brameier, Markus; Walter, Lutz; Mayne, Ann E.; Dunbar, Paul; Russo, Robert; Little, Dawn M.; Villinger, Tara; Khowawisetsut, Ladawan; Pattanapanyasat, Kovit; Villinger, Francois; Ansari, Aftab A.

2014-01-01

The studies reported herein are the first to document the effect of the in vivo administration of a JAK3 inhibitor for defining the potential role of NK cells during acute SIV infection of a group of 15 rhesus macaques (RM). An additional group of 16 MHC/KIR typed RM was included as controls. The previously optimized in vivo dose regimen (20 mg/kg daily for 35 days) led to a marked depletion of each of the major NK cell subsets both in the blood and gastro-intestinal tissues (GIT) during acute infection. While such depletion had no detectable effects on plasma viral loads during acute infection, there was a significant sustained increase in plasma viral loads during chronic infection. While the potential mechanisms that lead to such increased plasma viral loads during chronic infection remain unclear, several correlates were documented. Thus, during acute infection, the administration of the JAK3 inhibitor besides depleting all NK cell subsets also decreased some CD8+ T cells and inhibited the mobilization of the plasmacytoid dendritic cells in the blood and their localization to the GIT. Of interest is the finding that the administration of the JAK3 inhibitor during acute infection also resulted in the sustained maintenance during chronic infection of a high number of naïve and central memory CD4+ T cells, increases in B cells in the blood, but decreases in the frequencies and function of NKG2a+ NK cells within the GIT and blood, respectively. These data identify a unique role for JAK3 inhibitor sensitive cells, that includes NK cells during acute infection that in concert lead to high viral loads in SIV infected RM during chronic infection without affecting detectable changes in antiviral humoral/cellular responses. Identifying the precise mechanisms by which JAK3 sensitive cells exert their influence is critical with important implications for vaccine design against lentiviruses. PMID:24603870

Chronic alcohol increases CD8+ T-cell immunosenescence in simian immunodeficiency virus-infected rhesus macaques.

PubMed

Katz, Paige S; Siggins, Robert W; Porretta, Connie; Armstrong, Megan L; Zea, Arnold H; Mercante, Donald E; Parsons, Christopher; Veazey, Ronald S; Bagby, Gregory J; Nelson, Steve; Molina, Patricia E; Welsh, David A

2015-12-01

Activated CD8+ T-cells correlate with viral load and may foretell antiretroviral therapy (ART) failure. HIV infection has been suggested to accelerate immunosenescence through chronic persistent inflammation. Alcohol-use disorders (AUD) are prevalent in persons living with HIV/AIDS (PLWHA). We tested the hypothesis that hazardous alcohol consumption accelerates immune activation and immunosenescence. Immune activation and immunosenescence were examined in CD8+ T lymphocytes (CD3+CD4-CD8+) isolated from intestinal biopsies, axillary lymph nodes, and peripheral blood mononuclear cells (PBMCs) of chronic binge alcohol (CBA)-consuming simian immunodeficiency virus (SIV)-infected male rhesus macaques with and without antiretroviral therapy (ART; CBA/ART+, CBA/ART-) and in PBMCs isolated from a cohort of PLWHA. Polychromatic flow cytometry was used to phenotype cells isolated from intestinal biopsies, lymph nodes, and peripheral blood from rhesus macaques and PLWHA. The Alcohol Use Disorders Identification Test (AUDIT) identified hazardous alcohol drinking in PLWHA. Viral load was determined by RT-qPCR and telomere length was measured using qPCR. PBMC CD8+ T-cell activation (CD38+HLA-DR+) and immunosenescence (CD28-) were increased over baseline levels (857% ± 334, p < 0.05; 398% ± 80, p < 0.05, respectively) only in CBA animals not receiving ART. Viral load correlated with CD8+ T-cell immunosenescence in macaque PBMCs (r(s) = 0.49, p = 0.02). Activated immunosenescent T-cell (CD8+CD38+CD28-) frequencies in PBMCs from PLWHA significantly correlated with AUDIT scores (r(s) = 0.75, p = 0.001), while no correlation was observed with CD4+ T-cell and AUDIT scores (r(s) = -0.24, p = 0.38). Activated immunosenescent T-cells had shorter telomeres than CD8+ T-cells (CD8+CD28+) from PLWHA. Our results suggest that CBA and AUD augment immune activation and immunosenescence in SIV-infected macaques and PLWHA. Copyright © 2015 Elsevier Inc. All rights reserved.

Accumulation of Cytotoxic CD16+ NK Cells in Simian Immunodeficiency Virus-Infected Lymph Nodes Associated with In Situ Differentiation and Functional Anergy.

PubMed

Schafer, Jamie L; Li, Haiying; Evans, Tristan I; Estes, Jacob D; Reeves, R Keith

2015-07-01

Recent evidence suggests that even in treated infections, human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication may continue in lymph nodes (LN), serving as a potential virus reservoir. Here we investigated the effects of lentivirus infection on natural killer (NK) cell frequencies, phenotypes, and functions in naive and acutely or chronically SIVmac239-infected rhesus macaques. Compared to that in naive animals, we observed a 3-fold-greater frequency of cytotoxic CD16(+) CD56(-) NK cells in LN of chronically infected macaques. However, NK cells did not appear to be trafficking to LN, as homing markers CD62L and CCR7 did not increase on circulating NK cells during infection. LN NK cells demonstrated enhanced cytotoxicity in acute infection, with 2-fold increases in perforin expression and 3-fold increases in CD107a expression following mitogen stimulation. Lysis of K562 cells by LN NK cells from acutely infected animals was greater than lysis by preinfection samples from the same animals. LN NK cells from chronically infected animals lysed K562 cells more efficiently than LN NK cells from uninfected animals, but importantly, surrogate markers of cytotoxicity in infected macaques were disproportionately greater than ex vivo killing. Furthermore, Tim-3, an indicator of activation and/or exhaustion, was upregulated 3-fold on LN NK cells in chronically infected animals. Collectively, these data suggest that LN NK cells are skewed toward a cytotoxic phenotype during SIV infection but may become dysfunctional and exhausted in chronic disease. The accumulation of CD16(+) CD56(-) NK cells in the SIV-infected lymph node without changes in NK homing to the LN could suggest that these cells are differentiating in situ. Surprisingly, this increase in frequency of the cytotoxic subset of NK cells is not accompanied by an increase of similar magnitude in the cytolytic function of LN lymphocytes. This functional modulation, together with the

Antifungal Activity of Plasmacytoid Dendritic Cells and the Impact of Chronic HIV Infection.

PubMed

Maldonado, Samuel; Fitzgerald-Bocarsly, Patricia

2017-01-01

Due to the effectiveness of combined antiretroviral therapy, people living with HIV can control viral replication and live longer lifespans than ever. However, HIV-positive individuals still face challenges to their health and well-being, including dysregulation of the immune system resulting from years of chronic immune activation, as well as opportunistic infections from pathogenic fungi. This review focuses on one of the key players in HIV immunology, the plasmacytoid dendritic cell (pDC), which links the innate and adaptive immune response and is notable for being the body's most potent producer of type-I interferons (IFNs). During chronic HIV infection, the pDC compartment is greatly dysregulated, experiencing a substantial depletion in number and compromise in function. This immune dysregulation may leave patients further susceptible to opportunistic infections. This is especially important when considering a new role for pDCs currently emerging in the literature: in addition to their role in antiviral immunity, recent studies suggest that pDCs also play an important role in antifungal immunity. Supporting this new role, pDCs express C-type lectin receptors including dectin-1, dectin-2, dectin-3, and mannose receptor, and toll-like receptors-4 and -9 that are involved in recognition, signaling, and response to a wide variety of fungal pathogens, including Aspergillus fumigatus, Cryptococcus neoformans, Candida albicans , and Pneumocystis jirovecii . Accordingly, pDCs have been demonstrated to recognize and respond to certain pathogenic fungi, measured via activation, cytokine production, and fungistatic activity in vitro , while in vivo mouse models indicated a strikingly vital role for pDCs in survival against pulmonary Aspergillus challenge. Here, we discuss the role of the pDC compartment and the dysregulation it undergoes during chronic HIV infection, as well as what is known so far about the role and mechanisms of pDC antifungal activity.

Dysregulation of Antiviral Function of CD8(+) T Cells in the Chronic Obstructive Pulmonary Disease Lung. Role of the PD-1-PD-L1 Axis.

PubMed

McKendry, Richard T; Spalluto, C Mirella; Burke, Hannah; Nicholas, Ben; Cellura, Doriana; Al-Shamkhani, Aymen; Staples, Karl J; Wilkinson, Tom M A

2016-03-15

Patients with chronic obstructive pulmonary disease (COPD) are susceptible to respiratory viral infections that cause exacerbations. The mechanisms underlying this susceptibility are not understood. Effectors of the adaptive immune response-CD8(+) T cells that clear viral infections-are present in increased numbers in the lungs of patients with COPD, but they fail to protect against infection and may contribute to the immunopathology of the disease. CD8(+) function and signaling through the programmed cell death protein (PD)-1 exhaustion pathway were investigated as a potential key mechanism of viral exacerbation of the COPD lung. Tissue from control subjects and patients with COPD undergoing lung resection was infected with live influenza virus ex vivo. Viral infection and expression of lung cell markers were analyzed using flow cytometry. The proportion of lung CD8(+) T cells expressing PD-1 was greater in COPD (mean, 16.2%) than in controls (4.4%, P = 0.029). Only epithelial cells and macrophages were infected with influenza, and there was no difference in the proportion of infected cells between controls and COPD. Infection up-regulated T-cell PD-1 expression in control and COPD samples. Concurrently, influenza significantly up-regulated the marker of cytotoxic degranulation (CD107a) on CD8(+) T cells (P = 0.03) from control subjects but not on those from patients with COPD. Virus-induced expression of the ligand PD-L1 was decreased on COPD macrophages (P = 0.04) with a corresponding increase in IFN-γ release from infected COPD explants compared with controls (P = 0.04). This study has established a signal of cytotoxic immune dysfunction and aberrant immune regulation in the COPD lung that may explain both the susceptibility to viral infection and the excessive inflammation associated with exacerbations.

Preserved MHC-II antigen processing and presentation function in chronic HCV infection

PubMed Central

DH, Canaday; CJ, Burant; L, Jones; H, Aung; L, Woc-Colburn; DD, Anthony

2010-01-01

Individuals with chronic HCV infection have impaired response to vaccine, though the etiology remains to be elucidated. Dendritic cells (DC) and monocytes (MN) provide antigen uptake, processing, presentation, and costimulatory functions necessary to achieve optimal immune responses. The integrity of antigen processing and presentation function within these antigen presenting cells (APC) in the setting of HCV infection has been unclear. We used a novel T cell hybridoma system that specifically measures MHC-II antigen processing and presentation function of human APC. Results demonstrate MHC-II antigen processing and presentation function is preserved in both myeloid DC (mDC) and MN in the peripheral blood of chronically HCV-infected individuals, and indicates that an alteration in this function does not likely underlie the defective HCV-infected host response to vaccination. PMID:21055734

Hyper-Expression of PD-1 Is Associated with the Levels of Exhausted and Dysfunctional Phenotypes of Circulating CD161++TCR iVα7.2+ Mucosal-Associated Invariant T Cells in Chronic Hepatitis B Virus Infection.

PubMed

Yong, Yean K; Saeidi, Alireza; Tan, Hong Y; Rosmawati, Mohamed; Enström, Philip F; Batran, Rami Al; Vasuki, V; Chattopadhyay, Indranil; Murugesan, Amudhan; Vignesh, Ramachandran; Kamarulzaman, Adeeba; Rajarajeswaran, Jayakumar; Ansari, Abdul W; Vadivelu, Jamuna; Ussher, James E; Velu, Vijayakumar; Larsson, Marie; Shankar, Esaki M

2018-01-01

Mucosal-associated invariant T (MAIT) cells, defined as CD161 ++ TCR iVα7.2 + T cells, play an important role in the innate defense against bacterial infections, and their functionality is impaired in chronic viral infections. Here, we investigated the frequency and functional role of MAIT cells in chronic hepatitis B virus (HBV) infection. The peripheral CD3 + CD161 ++ TCR iVα7.2 + MAIT cells in chronic HBV-infected patients and healthy controls were phenotypically characterized based on CD57, PD-1, TIM-3, and CTLA-4, as well as HLA-DR and CD38 expression. The frequency of MAIT cells was significantly decreased among chronic HBV-infected individuals as compared to controls. Expression of CD57, PD-1, CTLA-4, as well as HLA-DR and CD38 on MAIT cells was significantly elevated in chronic HBV-infected individuals relative to controls. The percentage of T cell receptor (TCR) iVα7.2 + CD161 + MAIT cells did not correlate with HBV viral load but inversely with HLA-DR on CD4 + T cells and MAIT cells and with CD57 on CD8 + T cells suggesting that decrease of MAIT cells may not be attributed to direct infection by HBV but driven by HBV-induced chronic immune activation. The percentage and expression levels of PD-1 as well as CTLA-4 on MAIT cells inversely correlated with plasma HBV-DNA levels, which may suggest either a role for MAIT cells in the control of HBV infection or the effect of HBV replication in the liver on MAIT cell phenotype. We report that decrease of TCR iVα7.2 + MAIT cells in the peripheral blood and their functions were seemingly impaired in chronic HBV-infected patients likely because of the increased expression of PD-1.

A monoclonal expansion of Epstein-Barr virus-infected natural killer cells after allogeneic peripheral blood stem cell transplantation.

PubMed

Isobe, Yasushi; Hamano, Yasuharu; Ito, Yoshinori; Kimura, Hiroshi; Tsukada, Nobuhiro; Sugimoto, Koichi; Komatsu, Norio

2013-02-01

Here, we describe a Japanese woman showing a monoclonal expansion of EBV-infected natural killer (NK) cells after receiving allogeneic peripheral blood stem cell transplantation (PBSCT). The patient initially had T-cell-type chronic active EBV disease (CAEBV) and subsequently developed liver T-cell lymphoma. L-Asparaginase-containing chemotherapy led to a favorable lymphoma response. To eradicate CAEBV and the lymphoma, she further received allogeneic PBSCT from a human leukocyte antigen-matched sibling donor. After the PBSCT, the patient presented with transient lymphocytosis of NK cells, which were infected with a monoclonal EBV strain other than previously detected ones. These NK cells seemed to have been transmitted from the healthy donor to the recipient. The patient and donor remain well in spite of carrying these NK cells. This is the first report of an asymptomatic Japanese carrier harboring monoclonal EBV-infected NK cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Active myocarditis in a patient with chronic active Epstein-Barr virus infection.

PubMed

Takano, Hiroyuki; Nakagawa, Keiichi; Ishio, Naoki; Daimon, Michiko; Daimon, Masao; Kobayashi, Yoshio; Hiroshima, Kenzo; Komuro, Issei

2008-10-30

Chronic active Epstein-Barr virus (CAEBV) infection is characterized by chronic or recurrent infectious mononucleosis-like symptoms and the prognosis of CAEBV infection is quite poor. The incidence of myocarditis as a complication of EBV infection is not so high and it is unusual that heart failure appears as the initial symptom. However, it is very important to detect and treat chronic active myocarditis in the early phase of CAEBV infection because chronic active myocarditis disorganizes and decreases cardiomyocytes, resulting in the progression to heart failure. We report a case of a 45-year-old man with CAEBV infection for 5 years. Echocardiography revealed moderate left ventricular systolic dysfunction with mild pericardial effusion. Endomyocardial biopsies demonstrated massive lymphocytic infiltration with adjacent myocytolysis and necrosis of cardiomyocytes suggesting active myocarditis. Immunohistological analysis of biopsies revealed that the infiltrating cells were mainly T lymphocytes. And some of the infiltrating cells showed a positive signal for the EBV-encoded small nuclear RNA by in situ hybridization. Positron emission tomography using (18)F-fluoro-2-deoxyglucose ((18)F-FDG) performed revealed increased uptake of (18)F-FDG of whole left ventricular wall with mild heterogeneity.

Recurrence of chronic active Epstein-Barr virus infection from donor cells after achieving complete response through allogeneic bone marrow transplantation.

PubMed

Arai, Ayako; Imadome, Ken-ichi; Wang, Ludan; Wu, Nan; Kurosu, Tetsuya; Wake, Atsushi; Yamamoto, Hisashi; Ota, Yasunori; Harigai, Masayoshi; Fujiwara, Shigeyoshi; Miura, Osamu

2012-01-01

We report the case of a 35-year-old woman with chronic active Epstein-Barr virus (EBV) infection (CAEBV). She underwent allogeneic bone marrow transplantation (BMT) from an unrelated male donor and achieved a complete response. However, her CAEBV relapsed one year after BMT. EBV-infected cells proliferated clonally and revealed a 46XY karyotype. In addition, the infecting EBV strain differed from that detected before BMT. These findings indicated that her disease had developed from donor cells. This is the first report of donor cell-derived CAEBV that recurred after transplantation, suggesting that host factors may be responsible for the development of this disease.

Phenotypic complementation of genetic immunodeficiency by chronic herpesvirus infection.

PubMed

MacDuff, Donna A; Reese, Tiffany A; Kimmey, Jacqueline M; Weiss, Leslie A; Song, Christina; Zhang, Xin; Kambal, Amal; Duan, Erning; Carrero, Javier A; Boisson, Bertrand; Laplantine, Emmanuel; Israel, Alain; Picard, Capucine; Colonna, Marco; Edelson, Brian T; Sibley, L David; Stallings, Christina L; Casanova, Jean-Laurent; Iwai, Kazuhiro; Virgin, Herbert W

2015-01-20

Variation in the presentation of hereditary immunodeficiencies may be explained by genetic or environmental factors. Patients with mutations in HOIL1 (RBCK1) present with amylopectinosis-associated myopathy with or without hyper-inflammation and immunodeficiency. We report that barrier-raised HOIL-1-deficient mice exhibit amylopectin-like deposits in the myocardium but show minimal signs of hyper-inflammation. However, they show immunodeficiency upon acute infection with Listeria monocytogenes, Toxoplasma gondii or Citrobacter rodentium. Increased susceptibility to Listeria was due to HOIL-1 function in hematopoietic cells and macrophages in production of protective cytokines. In contrast, HOIL-1-deficient mice showed enhanced control of chronic Mycobacterium tuberculosis or murine γ-herpesvirus 68 (MHV68), and these infections conferred a hyper-inflammatory phenotype. Surprisingly, chronic infection with MHV68 complemented the immunodeficiency of HOIL-1, IL-6, Caspase-1 and Caspase-1;Caspase-11-deficient mice following Listeria infection. Thus chronic herpesvirus infection generates signs of auto-inflammation and complements genetic immunodeficiency in mutant mice, highlighting the importance of accounting for the virome in genotype-phenotype studies.

FLOW MEDIATED DILATION AND CAROTID INTIMA MEDIA THICKNESS IN PATIENTS WITH CHRONIC GASTRITIS ASSOCIATED WITH HELICOBACTER PYLORI INFECTION.

PubMed

Judaki, Arezo; Norozi, Siros; Ahmadi, Mohammad Reza Hafezi; Ghavam, Samira Mis; Asadollahi, Khairollah; Rahmani, Asghar

2017-12-01

Endothelial dysfunction is one of the early stages of vascular diseases. The aim of this study was to investigate the endothelial dysfunction markers in patients with chronic gastritis associated with Helicobacter pylori (H. pylori) infection. By a cross sectional study, basic and clinical information of 120 participants (40 patients with positive H. pylori infection, 40 patients with negative H. pylori infection and 40 healthy people) were analyzed. Carotid intima media thickness and flow-mediated dilation levels were measured in all patients and controls. Soluble vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were measured with Elisa for all subjects. IgG level was assessed in chronic gastritis patients. The flow-mediated dilation level in patients with positive H. pylori infection (0.17%±0.09) was significantly lower than those with negative H. pylori infection (0.21% ±0.10, P<0.05) and compared to the control group (0.27% ±0.11, P<0.05). Carotid intima media thickness level in patients with positive H. pylori infection (0.58±0.13 mm) was significantly higher than those with negative H. pylori infection (0.48±0.32 mm, P<0.05) and compared to the control group (0.36±0.44mm, P<0.05). The mean level of sICAM-1 in positive H. pylori infection group (352.16±7.54 pg/mL) was higher than negative H. pylori infection group (332.64±8.75 pg/mL =0.75) and compared to the control group (236.32±12.43 pg/mL, P<0.05). A direct relationship was revealed between flow-mediated dilation and carotid intima media thickness changes and between sICAM-1 and sVCAM-1 associated with the level of H. pylori IgG in chronic gastritis. The levels of flow-mediated dilation, carotid intima media thickness and sICAM-1 were higher among patients with positive H. pylori infection. Patients with chronic gastritis associated with H. pylori infection are at risk of endothelial dysfunction due to flow-mediated dilation and carotid intima media

Role of latent membrane protein 1 in chronic active Epstein–Barr virus infection-derived T/NK-cell proliferation

PubMed Central

Ito, Takuto; Kawazu, Hidetaka; Murata, Takayuki; Iwata, Seiko; Arakawa, Saki; Sato, Yoshitaka; Kuzushima, Kiyotaka; Goshima, Fumi; Kimura, Hiroshi

2014-01-01

Epstein–Barr virus (EBV) predominantly infects B cells and causes B-cell lymphomas, such as Burkitt lymphoma and Hodgkin lymphoma. However, it also infects other types of cells, including T and natural killer (NK) cells, and causes disorders, such as chronic active EBV infection (CAEBV) and T/NK-cell lymphoma. The CAEBV is a lymphoproliferative disease with poor prognosis, where EBV-positive T or NK cells grow rapidly, although the molecular mechanisms that cause the cell expansion still remain to be elucidated. EBV-encoded latent membrane protein 1 (LMP1) is an oncogene that can transform some cell types, such as B cells and mouse fibroblasts, and thus may stimulate cell proliferation in CAEBV. Here, we examined the effect of LMP1 on EBV-negative cells using the cells conditionally expressing LMP1, and on CAEBV-derived EBV-positive cells by inhibiting the function of LMP1 using a dominant negative form of LMP1. We demonstrated that LMP1 was responsible for the increased cell proliferation in the cell lines derived from CAEBV, while LMP1 did not give any proliferative advantage to the EBV-negative cell line. PMID:24799376

Dysregulation of Antiviral Function of CD8+ T Cells in the Chronic Obstructive Pulmonary Disease Lung. Role of the PD-1–PD-L1 Axis

PubMed Central

McKendry, Richard T.; Spalluto, C. Mirella; Burke, Hannah; Nicholas, Ben; Cellura, Doriana; Al-Shamkhani, Aymen; Staples, Karl J.

2016-01-01

Rationale: Patients with chronic obstructive pulmonary disease (COPD) are susceptible to respiratory viral infections that cause exacerbations. The mechanisms underlying this susceptibility are not understood. Effectors of the adaptive immune response—CD8+ T cells that clear viral infections—are present in increased numbers in the lungs of patients with COPD, but they fail to protect against infection and may contribute to the immunopathology of the disease. Objectives: CD8+ function and signaling through the programmed cell death protein (PD)-1 exhaustion pathway were investigated as a potential key mechanism of viral exacerbation of the COPD lung. Methods: Tissue from control subjects and patients with COPD undergoing lung resection was infected with live influenza virus ex vivo. Viral infection and expression of lung cell markers were analyzed using flow cytometry. Measurements and Main Results: The proportion of lung CD8+ T cells expressing PD-1 was greater in COPD (mean, 16.2%) than in controls (4.4%, P = 0.029). Only epithelial cells and macrophages were infected with influenza, and there was no difference in the proportion of infected cells between controls and COPD. Infection up-regulated T-cell PD-1 expression in control and COPD samples. Concurrently, influenza significantly up-regulated the marker of cytotoxic degranulation (CD107a) on CD8+ T cells (P = 0.03) from control subjects but not on those from patients with COPD. Virus-induced expression of the ligand PD-L1 was decreased on COPD macrophages (P = 0.04) with a corresponding increase in IFN-γ release from infected COPD explants compared with controls (P = 0.04). Conclusions: This study has established a signal of cytotoxic immune dysfunction and aberrant immune regulation in the COPD lung that may explain both the susceptibility to viral infection and the excessive inflammation associated with exacerbations. PMID:26517304

Role of L-Particles during Herpes Simplex Virus Infection.

PubMed

Heilingloh, Christiane S; Krawczyk, Adalbert

2017-01-01

Infection of eukaryotic cells with α-herpesviruses results in the formation and secretion of infectious heavy particles (virions; H-particles) and non-infectious light particles (L-particles). Herpes simplex virus type 1 (HSV-1) H-particles consist of a genome-containing capsid surrounded by tegument proteins and a glycoprotein-rich lipid bilayer. Non-infectious L-particles are composed mainly of envelope and tegument proteins and are devoid of capsids and viral DNA. L-particles were first described in the early nineties and from then on investigated for their formation and role during virus infection. The development and secretion of L-particles occur simultaneously to the assembly of complete viral particles. HSV-1 L-particles are assembled by budding of condensed tegument into Golgi-delivered vesicles and are capable of delivering their functional content to non-infected cells. Thereby, HSV-1 L-particles contribute to viral pathogenesis within the infected host by enhancing virion infectivity and providing immune evasion functions. In this review we discuss the emergence of HSV-1 L-particles during virus replication and their biological functions described thus far.

Intensification of Antiretroviral Therapy with a CCR5 Antagonist in Patients with Chronic HIV-1 Infection: Effect on T Cells Latently Infected

PubMed Central

Vallejo, Alejandro; Hernández-Novoa, Beatriz; Abad, María; Madrid, Nadia; Dahl, Viktor; Rubio, Rafael; Moreno, Ana M.; Dronda, Fernando; Casado, José Luis; Navas, Enrique; Pérez-Elías, María Jesús; Zamora, Javier; Palmer, Sarah; Muñoz, Eduardo; Muñoz-Fernández, María Ángeles; Moreno, Santiago

2011-01-01

Objective The primary objective was to assess the effect of MVC intensification on latently infected CD4+ T cells in chronically HIV-1-infected patients receiving antiretroviral therapy. Methods We performed an open-label pilot phase II clinical trial involving chronically HIV-1-infected patients receiving stable antiretroviral therapy whose regimen was intensified with 48 weeks of maraviroc therapy. We analyzed the latent reservoir, the residual viremia and episomal 2LTR DNA to examine the relationship between these measures and the HIV-1 latent reservoir, immune activation, lymphocyte subsets (including effector and central memory T cells), and markers associated with bacterial translocation. Results Overall a non significant reduction in the size of the latent reservoir was found (p = 0.068). A mean reduction of 1.82 IUPM was observed in 4 patients with detectable latent reservoir at baseline after 48 weeks of intensification. No effect on plasma residual viremia was observed. Unexpectedly, all the patients had detectable 2LTR DNA circles at week 24, while none of them showed those circles at the end of the study. No changes were detected in CD4+ or CD8+ counts, although a significant decrease was found in the proportion of HLA-DR+/CD38+ CD4+ and CD8+ T-cells. LPS and sCD14 levels increased. Conclusions Intensification with MVC was associated with a trend to a decrease in the size of the latent HIV-1 reservoir in memory T cells. No impact on residual viremia was detected. Additional studies with larger samples are needed to confirm the results. Trial Registration ClinicalTrials.gov NCT00795444 PMID:22174752

Reduced Expression of Siglec-7, NKG2A, and CD57 on Terminally Differentiated CD56-CD16+ Natural Killer Cell Subset Is Associated with Natural Killer Cell Dysfunction in Chronic HIV-1 Clade C Infection.

PubMed

Zulu, Michael Z; Naidoo, Kewreshini K; Mncube, Zenele; Jaggernath, Manjeetha; Goulder, Philip J R; Ndung'u, Thumbi; Altfeld, Marcus; Thobakgale, Christina F

2017-12-01

HIV-1 viremia has been shown to induce several phenotypic and functional abnormalities in natural killer (NK) cells. To assess immune defects associated with HIV viremia, we examined NK cell function, differentiation status, and phenotypic alterations based on expression of inhibitory and activating receptors on NK cells in HIV-1 subtype C chronically infected participants from Durban, South Africa. NK cell phenotypic profiles were characterized by assessing sialic acid-binding immunoglobulin-like lectin-7 (Siglec-7), NKG2A, and NKG2C markers on frozen peripheral blood mononuclear cells from viremic, antiretroviral therapy (ART)-naive HIV-1 chronically infected participants (n = 23), HIV-1 chronically infected participants who had been on combination antiretroviral therapy (cART) for at least 12 months (n = 23) compared with healthy donors (n = 23). NK cell differentiation was assessed by measurement of killer immunoglobulin receptor (KIR) and NKG2A expression; CD57 and CD107a measurements were carried out in HIV viremic and healthy donors. All phenotypic and functional assessments were analyzed by using multicolor flow cytometry. HIV-1-infected participants displayed greater frequencies of the CD56 - CD16 + (CD56negative) NK cell subset compared with healthy donors (p < .0001). Downregulation of Siglec-7 and NKG2A and upregulation of NKG2C were more pronounced in the CD56negative NK cell subset of viremic participants. The CD56negative subset demonstrated a differentiated (KIR + NKG2A - ) phenotype with reduced CD57 expression and lower degranulation capacity in HIV-1-infected participants compared with healthy donors. HIV-1 infection induces the expansion of the CD56negative NK cell subset marked by altered receptor expression profiles that are indicative of impaired function and may explain the overall NK cell dysfunction observed in chronic HIV-1 infection.

Suppression of NYVAC Infection in HeLa Cells Requires RNase L but Is Independent of Protein Kinase R Activity

PubMed Central

Fernández-Escobar, Mercedes; Nájera, José Luis; Baldanta, Sara; Rodriguez, Dolores; Way, Michael; Esteban, Mariano

2015-01-01

Protein kinase R (PKR) and RNase L are host cell components that function to contain viral spread after infections. In this study, we analyzed the role of both proteins in the abortive infection of human HeLa cells with the poxvirus strain NYVAC, for which an inhibition of viral A27L and B5R gene expression is described. Specifically, the translation of these viral genes is independent of PKR activation, but their expression is dependent on the RNase L activity. PMID:26656695

Role of latent membrane protein 1 in chronic active Epstein-Barr virus infection-derived T/NK-cell proliferation.

PubMed

Ito, Takuto; Kawazu, Hidetaka; Murata, Takayuki; Iwata, Seiko; Arakawa, Saki; Sato, Yoshitaka; Kuzushima, Kiyotaka; Goshima, Fumi; Kimura, Hiroshi

2014-08-01

Epstein-Barr virus (EBV) predominantly infects B cells and causes B-cell lymphomas, such as Burkitt lymphoma and Hodgkin lymphoma. However, it also infects other types of cells, including T and natural killer (NK) cells, and causes disorders, such as chronic active EBV infection (CAEBV) and T/NK-cell lymphoma. The CAEBV is a lymphoproliferative disease with poor prognosis, where EBV-positive T or NK cells grow rapidly, although the molecular mechanisms that cause the cell expansion still remain to be elucidated. EBV-encoded latent membrane protein 1 (LMP1) is an oncogene that can transform some cell types, such as B cells and mouse fibroblasts, and thus may stimulate cell proliferation in CAEBV. Here, we examined the effect of LMP1 on EBV-negative cells using the cells conditionally expressing LMP1, and on CAEBV-derived EBV-positive cells by inhibiting the function of LMP1 using a dominant negative form of LMP1. We demonstrated that LMP1 was responsible for the increased cell proliferation in the cell lines derived from CAEBV, while LMP1 did not give any proliferative advantage to the EBV-negative cell line. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Inflammatory cytokine production in chronic active Epstein-Barr virus infection.

PubMed

Onozawa, Erika; Shibayama, Haruna; Imadome, Ken-Ichi; Tsuzura, Akiho; Koyama, Takatoshi; Miura, Osamu; Arai, Ayako

2017-01-01

In order to clarify the mechanisms underlying the development of inflammation in chronic active Epstein-Barr virus infection (CABEV), we examined cytokine production using patient samples. Eleven patients were analyzed. The serum concentrations of IFN-γ, TNF-α, and IL-6 were significantly higher in patients than in healthy donors. The mRNAs of these cytokines in peripheral blood mononuclear cells were elevated in patients as compared with healthy donors. The mRNA of IFN-γ was significantly higher in patients than in healthy donors. We examined which fraction produced the cytokines in the CD4-, CD8-, and CD56-positive fractions of PBMCs. The mRNAs of IFN-γ, TNF-α, and IL-6 were highly expressed in EBV-infected cells, whereas expression was also observed in non-infected cells. We performed in vitro infection of EBV on a T-cell line, MOLT4. EBV infection enhanced the mRNA expressions of IFN-γ and TNF-α. These results suggest that the inflammatory cytokines in CAEBV are produced not only by EBV-infected but also non-infected cells. EBV itself may have roles in the cytokine production observed in infected cells.

Phenotypic complementation of genetic immunodeficiency by chronic herpesvirus infection

PubMed Central

MacDuff, Donna A; Reese, Tiffany A; Kimmey, Jacqueline M; Weiss, Leslie A; Song, Christina; Zhang, Xin; Kambal, Amal; Duan, Erning; Carrero, Javier A; Boisson, Bertrand; Laplantine, Emmanuel; Israel, Alain; Picard, Capucine; Colonna, Marco; Edelson, Brian T; Sibley, L David; Stallings, Christina L; Casanova, Jean-Laurent; Iwai, Kazuhiro; Virgin, Herbert W

2015-01-01

Variation in the presentation of hereditary immunodeficiencies may be explained by genetic or environmental factors. Patients with mutations in HOIL1 (RBCK1) present with amylopectinosis-associated myopathy with or without hyper-inflammation and immunodeficiency. We report that barrier-raised HOIL-1-deficient mice exhibit amylopectin-like deposits in the myocardium but show minimal signs of hyper-inflammation. However, they show immunodeficiency upon acute infection with Listeria monocytogenes, Toxoplasma gondii or Citrobacter rodentium. Increased susceptibility to Listeria was due to HOIL-1 function in hematopoietic cells and macrophages in production of protective cytokines. In contrast, HOIL-1-deficient mice showed enhanced control of chronic Mycobacterium tuberculosis or murine γ-herpesvirus 68 (MHV68), and these infections conferred a hyper-inflammatory phenotype. Surprisingly, chronic infection with MHV68 complemented the immunodeficiency of HOIL-1, IL-6, Caspase-1 and Caspase-1;Caspase-11-deficient mice following Listeria infection. Thus chronic herpesvirus infection generates signs of auto-inflammation and complements genetic immunodeficiency in mutant mice, highlighting the importance of accounting for the virome in genotype-phenotype studies. DOI: http://dx.doi.org/10.7554/eLife.04494.001 PMID:25599590

Depletion of CD8+ cells does not affect the lifespan of productively infected cells during pathogenic sivmac239 infection of rhesus macaques

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

Shudo, Emi; Ribeiro, Ruy M; Perelson, Alan S

2008-01-01

While CD8+ T cell responses are clearly important in anti-viral immunity during HIV/SIV infection, the mechanisms by which CD8+ T cells induce this effect remain poorly understood, as emphasized by the failure of the Merck adenovirus-based, cytotoxic T lymphocyte (CTL)-inducing AIDS vaccine in a large phase IIb clinical trial. In this study, we measured the in vivo effect of CD8+ lymphocytes on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques by treating two groups of animals (i.e., CD8+ lymphocyte-depleted or controls) with antiretroviral therapy (PMPA and FTC). The lifespan of productively infected cells was calculatedmore » based on the slope of the decline of SIV plasma viremia using a well-accepted mathematical model. We found that, in both early (i.e., day 57 post-inoculation) and late (i.e., day 177 post-inoculation) chronic SIV infection, depletion of CD8+ lymphocytes did not result in an increased lifespan of productively infected cells in vivo. This result indicates that direct killing of cells producing virus is unlikely to be a major mechanism underlying the anti-viral effect of CD8+ T cells during SIV infection. These results have profound implications for the development of AIDS vaccines.« less

The PD-1: PD-L1 pathway promotes development of brain-resident memory T cells following acute viral encephalitis.

PubMed

Prasad, Sujata; Hu, Shuxian; Sheng, Wen S; Chauhan, Priyanka; Singh, Amar; Lokensgard, James R

2017-04-13

Previous work from our laboratory has demonstrated that during acute viral brain infection, glial cells modulate antiviral T cell effector responses through the PD-1: PD-L1 pathway, thereby limiting the deleterious consequences of unrestrained neuroinflammation. Here, we evaluated the PD-1: PD-L1 pathway in development of brain-resident memory T cells (bT RM ) following murine cytomegalovirus (MCMV) infection. Flow cytometric analysis of immune cells was performed at 7, 14, and 30 days post-infection (dpi) to assess the shift of brain-infiltrating CD8 + T cell populations from short-lived effector cells (SLEC) to memory precursor effector cells (MPEC), as well as generation of bT RMs . In wild-type (WT) animals, we observed a switch in the phenotype of brain-infiltrating CD8 + T cell populations from KLRG1 + CD127 - (SLEC) to KLRG1 - CD127 + (MPEC) during transition from acute through chronic phases of infection. At 14 and 30 dpi, the majority of CD8 + T cells expressed CD127, a marker of memory cells. In contrast, fewer CD8 + T cells expressed CD127 within brains of infected, PD-L1 knockout (KO) animals. Notably, in WT mice, a large population of CD8 + T cells was phenotyped as CD103 + CD69 + , markers of bT RM , and differences were observed in the numbers of these cells when compared to PD-L1 KOs. Immunohistochemical studies revealed that brain-resident CD103 + bT RM cells were localized to the parenchyma. Higher frequencies of CXCR3 were also observed among WT animals in contrast to PD-L1 KOs. Taken together, our results indicate that bT RMs are present within the CNS following viral infection and the PD-1: PD-L1 pathway plays a role in the generation of this brain-resident population.

Epstein-Barr virus-positive cytotoxic T-cell lymphoma followed by chronic active Epstein-Barr virus infection-associated T/NK-cell lymphoproliferative disorder: a case report.

PubMed

Kato, Seiichi; Miyata, Tomoko; Takata, Katsuyoshi; Shimada, Satoko; Ito, Yoshinori; Tomita, Akihiro; Elsayed, Ahmed Ali; Takahashi, Emiko; Asano, Naoko; Kinoshita, Tomohiro; Kimura, Hiroshi; Nakamura, Shigeo

2013-12-01

A 30-year-old female patient presented with intestinal Epstein-Barr virus (EBV)-positive cytotoxic T-cell lymphoma (EBV+ CTL), which was surgically resected. Fourteen years later, she returned to our hospital with hypersensitivity to mosquito bites and was diagnosed with chronic active EBV infection-associated T/NK-cell lymphoproliferative disorder (CAEBV/TNK-LPD). She developed systemic EBV+ CTL at age 47 years during the 2.5-year clinical course of CAEBV/TNK-LPD, despite multiagent chemotherapy and allogeneic stem cell transplantation. Afterward, she had a rapidly deteriorating clinical course and died at age 48 years. The immunophenotype of the EBV+ CTL was consistently a CD3, CD8, and cytotoxic molecule-positive type with the same clonality in polymerase chain reaction analysis of T-cell receptor-γ chain gene rearrangement. This is the first reported case of EBV+ CTL preceding the clinical presentation of CAEBV/TNK-LPD. The present case was unique in suggesting a close relationship between EBV+ CTL and chronic active EBV infection. © 2013.

Generalized myositis mimicking polymyositis associated with chronic active Epstein-Barr virus infection.

PubMed

Uchiyama, Tomoyuki; Arai, Kimito; Yamamoto-Tabata, Takako; Hirai, Kanji; Kishimoto, Kouji; Nakamura, Yoshiko; Hattori, Takamichi

2005-05-01

Chronic generalized myositis has not so far been reported as a complication of chronic active Epstein-Barr virus infection (CAEBV). We encountered three patients with chronic generalized myositis mimicking polymyositis associated with CAEBV. To clarify the pathological character of this myositis, we investigated the distribution, clonality, and the immunophenotype of EBV-infected cells and lymphocytes infiltrating in muscles. Clinically, two patients showed symmetrical proximal weakness and muscle atrophy as the initial and main symptom. Although the condition resembled polymyositis, they had also lingual and/or orbital myositis. The other patient showed generalized myositis at the late phase of CAEBV. In all of them, immunotherapy was ineffective and prognosis was poor. Intramuscular infiltrating lymphocytes in our patients were mainly CD45RO+, CD3+, CD4-, CD8-, TCR betaF1-, TCR deltaTCS1-, CD56-, CD79a-, CD21-, HLA-DR+, ZEBRA -, LMP1-, and EBER+ T cells. Oligoclonal expansion of EBV-infected T cells was shown in the muscles. However, there were no malignant lymphocytes. This new form of myositis must be distinguished from polymyositis and the other conventional forms of myositis. Careful investigation of hidden CAEBV is recommended when patients present with steroid non-responsive chronic progressive generalized myositis, in particular, with lingual or orbital involvement.

CD40 agonist converting CTL exhaustion via the activation of the mTORC1 pathway enhances PD-1 antagonist action in rescuing exhausted CTLs in chronic infection

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

Xu, Aizhang; Wang, Rong; Department of Oncology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan

Expansion of PD-1-expressing CD8{sup +} cytotoxic T lymphocytes (CTLs) and associated CTL exhaustion are chief issues for ineffective virus-elimination in chronic infectious diseases. PD-1 blockade using antagonistic anti-PD-L1 antibodies results in a moderate conversion of CTL exhaustion. We previously demonstrated that CD40L signaling of ovalbumin (OVA)-specific vaccine, OVA-Texo, converts CTL exhaustion via the activation of the mTORC1 pathway in OVA-expressing adenovirus (AdVova)-infected B6 mice showing CTL inflation and exhaustion. Here, we developed AdVova-infected B6 and transgenic CD11c-DTR (termed AdVova-B6 and AdVova-CD11c-DTR) mice with chronic infection, and assessed a potential effect of CD40 agonist on the conversion of CTL exhaustion andmore » on a potential enhancement of PD-1 antagonist action in rescuing exhausted CTLs in our chronic infection models. We demonstrate that a single dose of anti-CD40 alone can effectively convert CTL exhaustion by activating the mTORC1 pathway, leading to CTL proliferation, up-regulation of an effector-cytokine IFN-γ and the cytolytic effect in AdVova-B6 mice. Using anti-CD4 antibody and diphtheria toxin (DT) to deplete CD4{sup +} T-cells and dendritic cells (DCs), we discovered that the CD40 agonist-induced conversion in AdVova-B6 and AdVova-CD11c-DTR mice is dependent upon host CD4{sup +} T-cell and DC involvements. Moreover, CD40 agonist significantly enhances PD-1 antagonist effectiveness in rescuing exhausted CTLs in chronic infection. Taken together, our data demonstrate the importance of CD40 signaling in the conversion of CTL exhaustion and its ability to enhance PD-1 antagonist action in rescuing exhausted CTLs in chronic infection. Therefore, our findings may positively impact the design of new therapeutic strategies for chronic infectious diseases. - Highlights: • Anti-CD40 agonistic Ab can convert CTL exhaustion in chronically infected mice. • The conversion relies on the activation of the mTORC1

Latent toxoplasmosis is associated with neurocognitive impairment in young adults with and without chronic HIV infection.

PubMed

Ene, L; Marcotte, T D; Umlauf, A; Grancea, C; Temereanca, A; Bharti, A; Achim, C L; Letendre, S; Ruta, S M

2016-10-15

We evaluated the impact of latent toxoplasmosis (LT) on neurocognitive (NC) and neurobehavioural functioning in young adults with and without chronic HIV infection, using a standardised NC test battery, self-reported Beck Depression Inventory, Frontal System Behavior Scale, MINI-International Neuropsychiatric Interview and risk-assessment battery. 194 young adults (median age 24years, 48.2% males) with chronic HIV infection (HIV+) since childhood and 51 HIV seronegative (HIV-) participants were included. HIV+ individuals had good current immunological status (median CD4: 479 cells/μl) despite a low CD4 nadir (median: 93 cells/μl). LT (positive anti-Toxoplasma IgG antibodies) was present in one third of participants. The impairment rates in the HIV- with and without Toxo were not significantly different (p=0.17). However, we observed an increasing trend (p<0.001) in impairment rates with HIV and LT status: HIV-/LT- (6.1%); HIV-/LT+ (22%), HIV+/LT- (31%), HIV+/LT+ (49%). In a multivariable analysis using the entire study group there were main effects on cognition for HIV and also for LT. Within the HIV+ group LT was associated with worse performance globally (p=0.006), in memory (p=0.009), speed of information processing (p=0.01), verbal (p=0.02) and learning (p=0.02) domains. LT was not associated with depressive symptoms, frontal systems dysfunction or risk behaviors in any of the groups. HIV participants with lower Toxoplasma antibody concentration had worse NC performance, with higher GDS values (p=0.03) and worse learning (p=0.002), memory (p=0.006), speed of information processing (p=0.01) T scores. Latent Toxoplasmosis may contribute to NC impairment in young adults, including those with and without chronic HIV infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Changes in the mitochondrial network during ectromelia virus infection of permissive L929 cells.

PubMed

Gregorczyk, Karolina P; Szulc-Dąbrowska, Lidia; Wyżewski, Zbigniew; Struzik, Justyna; Niemiałtowski, Marek

2014-01-01

Mitochondria are extremely important organelles in the life of a cell. Recent studies indicate that mitochondria also play a fundamental role in the cellular innate immune mechanisms against viral infections. Moreover, mitochondria are able to alter their shape continuously through fusion and fission. These tightly regulated processes are activated or inhibited under physiological or pathological (e.g. viral infection) conditions to help restore homeostasis. However, many types of viruses, such as orthopoxviruses, have developed various strategies to evade the mitochondrial-mediated antiviral innate immune responses. Moreover, orthopoxviruses exploit the mitochondria for their survival. Such viral activity has been reported during vaccinia virus (VACV) infection. Our study shows that the Moscow strain of ectromelia virus (ECTV-MOS), an orthopoxvirus, alters the mitochondrial network in permissive L929 cells. Upon infection, the branching structure of the mitochondrial network collapses and becomes disorganized followed by destruction of mitochondrial tubules during the late stage of infection. Small, discrete mitochondria co-localize with progeny virions, close to the cell membrane. Furthermore, clustering of mitochondria is observed around viral factories, particularly between the nucleus and viroplasm. Our findings suggest that ECTV-MOS modulates mitochondrial cellular distribution during later stages of the replication cycle, probably enabling viral replication and/or assembly as well as transport of progeny virions inside the cell. However, this requires further investigation.

Progressive CD4+ central–memory T cell decline results in CD4+ effector–memory insufficiency and overt disease in chronic SIV infection

PubMed Central

Okoye, Afam; Meier-Schellersheim, Martin; Brenchley, Jason M.; Hagen, Shoko I.; Walker, Joshua M.; Rohankhedkar, Mukta; Lum, Richard; Edgar, John B.; Planer, Shannon L.; Legasse, Alfred; Sylwester, Andrew W.; Piatak, Michael; Lifson, Jeffrey D.; Maino, Vernon C.; Sodora, Donald L.; Douek, Daniel C.; Axthelm, Michael K.; Grossman, Zvi; Picker, Louis J.

2007-01-01

Primary simian immunodeficiency virus (SIV) infections of rhesus macaques result in the dramatic depletion of CD4+ CCR5+ effector–memory T (TEM) cells from extra-lymphoid effector sites, but in most infections, an increased rate of CD4+ memory T cell proliferation appears to prevent collapse of effector site CD4+ TEM cell populations and acute-phase AIDS. Eventually, persistent SIV replication results in chronic-phase AIDS, but the responsible mechanisms remain controversial. Here, we demonstrate that in the chronic phase of progressive SIV infection, effector site CD4+ TEM cell populations manifest a slow, continuous decline, and that the degree of this depletion remains a highly significant correlate of late-onset AIDS. We further show that due to persistent immune activation, effector site CD4+ TEM cells are predominantly short-lived, and that their homeostasis is strikingly dependent on the production of new CD4+ TEM cells from central–memory T (TCM) cell precursors. The instability of effector site CD4+ TEM cell populations over time was not explained by increasing destruction of these cells, but rather was attributable to progressive reduction in their production, secondary to decreasing numbers of CCR5− CD4+ TCM cells. These data suggest that although CD4+ TEM cell depletion is a proximate mechanism of immunodeficiency, the tempo of this depletion and the timing of disease onset are largely determined by destruction, failing production, and gradual decline of CD4+ TCM cells. PMID:17724130

Transient FTY720 treatment promotes immune-mediated clearance of a chronic viral infection.

PubMed

Premenko-Lanier, Mary; Moseley, Nelson B; Pruett, Sarah T; Romagnoli, Pablo A; Altman, John D

2008-08-14

For a wide variety of microbial pathogens, the outcome of the infection is indeterminate. In some individuals the microbe is cleared, but in others it establishes a chronic infection, and the factors that tip this balance are often unknown. In a widely used model of chronic viral infection, C57BL/6 mice clear the Armstrong strain of lymphocytic choriomeningitis virus (LCMV), but the clone 13 strain persists. Here we show that the Armstrong strain induces a profound lymphopenia at days 1-3 after infection, but the clone 13 strain does not. If we transiently augment lymphopenia by treating the clone-13-infected mice with the drug FTY720 at days 0-2 after infection, the mice successfully clear the infection by day 30. Clearance does not occur when CD4 T cells are absent at the time of treatment, indicating that the drug is not exerting direct antiviral effects. Notably, FTY720 treatment of an already established persistent infection also leads to viral clearance. In both models, FTY720 treatment preserves or augments LCMV-specific CD4 and CD8 T-cell responses, a result that is counter-intuitive because FTY720 is generally regarded as a new immunosuppressive agent. Because FTY720 targets host pathways that are completely evolutionarily conserved, our results may be translatable into new immunotherapies for the treatment of chronic microbial infections in humans.

Intestinal immune cells in Strongyloides stercoralis infection.

PubMed Central

Trajman, A; MacDonald, T T; Elia, C C

1997-01-01

BACKGROUND: Strongyloides stercoralis can cause a wide spectrum of disease in man, ranging from a chronic asymptomatic infection to a hyperinfective, often fatal syndrome. In rodents, spontaneous expulsion of Strongyloides spp occurs after experimental infection. Mast cells, goblet cells, and eosinophils have been identified as possible effectors of this expulsion. AIMS: To investigate intestinal histopathology and mucosal immunity in immunocompetent patients with chronic S stercoralis infection. METHODS: Jejunal biopsies were performed in 19 immunocompetent patients with a positive stool examination for S stercoralis and few or no symptoms, and in seven healthy controls. Specimens were processed for histopathological analysis and stained by the immunoperoxidase technique, using the following monoclonal antibodies: CD2, CD3, CD4, CD8, anti-T cell receptor (TcR) gamma/delta, RFD1 and RFD7 (two different macrophage markers), Ki67+ (proliferating) cells, antihuman leucocyte antigen (HLA)-DR, and anticollagen IV. In addition, CD25+ cells, mast cells, IgE expressing cells, calprotectin containing cells, and neutrophil elastase positive cells were stained by the alkaline phosphatase method. RESULTS: Jejunal morphology and the numbers of different T cell subsets, mast cells, IgE expressing cells, eosinophils, and goblet cells were unaffected by S stercoralis infection. Conversely, the numbers of mature macrophages and dividing enterocytes in the crypts were reduced significantly. Crypt enterocytes did not express HLA-DR in both groups. The expression of HLA-DR by villus enterocytes was also comparable in patients and controls. There were no activated (CD25+) cells in the mucosa of either patients or controls. CONCLUSIONS: Compared with seven healthy uninfected volunteers, a group of 19 Brazilians with clinically mild strongyloides infection showed no abnormality of mucosal structure and no increase in non-specific inflammatory cells. Likewise, there was no increase in

L'Infection Nosocomiale en Reanimation des Brules

PubMed Central

Siah, S.; Belefqih, R.; Elouennass, M.; Fouadi, F.E.; Ihrai, I.

2009-01-01

Summary L'infection nosocomiale bactérienne étant l'une des principales causes de morbidité et de mortalité chez le brûlé, nous avons réalisé une étude rétrospective portant sur 84 patients hospitalisés au sein du service de réanimation des brûlés de l'Hôpital Militaire d'Instruction Mohammed V de Rabat, sur une période de 3 ans, du premier janvier 2001 au 31 décembre 2003. Les critères d'infection nosocomiale étaient ceux du Center for Disease Control d'Atlanta de 1988. Les taux d'incidence ont été calculés. La population infectée a été comparée à celle non infectée. L'écologie bactérienne du service a été décrite comme aussi l'antibiotype. Il ressort de cette étude la survenue de 87 infections nosocomiales chez 27 patients. L'incidence cumulative était de 103 infections pour 1000 jours de traitement. Pour ce qui est des caractéristiques des infections bactériennes, les sites infectés étaient la peau (77%), le sang (13,8%), les voies urinaires (8%) et les poumons (1,1%). Les principaux germes étaient: Staphylococcus sp. (33,3%), Pseudomonas aeruginosa (23%), Enterococcus faecalis et Acinetobacter (8%). Les staphylocoques étaient méticillo-résistants dans 22,2% des cas. Le Pseudomonas et l'Acinetobacter étaient multirésistants (60%). Dans notre étude les facteurs prédictifs de survenue des infections nosocomiales que nous avons retenus après l'étude comparative des populations infectées et non infectées ont été l'âge, le body mass index, l'abbreviated burn severity index et le remplissage initial. En isolant ces paramètres, nous avons pu établir une équation à valeur prédictive de survenue d'infection nosocomiale chez le patient brûlé. PMID:21991158

Persistent activation of an innate immune axis translates respiratory viral infection into chronic lung disease

PubMed Central

Kim, Edy Y.; Battaile, John T.; Patel, Anand C.; You, Yingjian; Agapov, Eugene; Grayson, Mitchell H.; Benoit, Loralyn A.; Byers, Derek E.; Alevy, Yael; Tucker, Jennifer; Swanson, Suzanne; Tidwell, Rose; Tyner, Jeffrey W.; Morton, Jeffrey D.; Castro, Mario; Polineni, Deepika; Patterson, G. Alexander; Schwendener, Reto A.; Allard, John D.; Peltz, Gary; Holtzman, Michael J.

2008-01-01

To understand the pathogenesis of chronic inflammatory disease, we analyzed an experimental mouse model of a chronic lung disease that resembles asthma and chronic obstructive pulmonary disease (COPD) in humans. In this model, chronic lung disease develops after infection with a common type of respiratory virus is cleared to trace levels of noninfectious virus. Unexpectedly, the chronic inflammatory disease arises independently of an adaptive immune response and is driven by IL-13 produced by macrophages stimulated by CD1d-dependent TCR-invariant NKT cells. This innate immune axis is also activated in the lungs of humans with chronic airway disease due to asthma or COPD. These findings provide new insight into the pathogenesis of chronic inflammatory disease with the discovery that the transition from respiratory viral infection into chronic lung disease requires persistent activation of a novel NKT cell-macrophage innate immune axis. PMID:18488036

Role of T. cruzi exposure in the pattern of T cell cytokines among chronically infected HIV and Chagas disease patients.

PubMed

Tozetto-Mendoza, Tania Regina; Vasconcelos, Dewton de Moraes; Ibrahim, Karim Yaqub; Sartori, Ana Marli Christovam; Bezerra, Rita C; Freitas, Vera Lúcia Teixeira de; Shikanai-Yasuda, Maria Aparecida

2017-11-01

The impact of Chagas disease (CD) in HIV-infected patients is relevant throughout the world. In fact, the characterization of the adaptive immune response in the context of co-infection is important for predicting the need for interventions in areas in which HIV and Chagas disease co-exist. We described and compared the frequency of cytokine-producing T cells stimulated with soluble antigen of Trypanosoma cruzi (T. cruzi) using a cytometric assay for the following groups: individuals with chronic Chagas disease (CHR, n=10), those with Chagas disease and HIV infection (CO, n=11), those with only HIV (HIV, n=14) and healthy individuals (C, n=15). We found 1) a constitutively lower frequency of IL-2+ and IFN-γ+ T cells in the CHR group compared with the HIV, CO and healthy groups; 2) a suppressive activity of soluble T. cruzi antigen, which down-regulated IL-2+CD4+ and IFN-γ+CD4+ phenotypes, notably in the healthy group; 3) a down-regulation of inflammatory cytokines on CD8+ T cells in the indeterminate form of Chagas disease; and 4) a significant increase in IL-10+CD8+ cells distinguishing the indeterminate form from the cardiac/digestive form of Chagas disease, even in the presence of HIV infection. Taken together, our data suggest the presence of an immunoregulatory response in chronic Chagas disease, which seems to be driven by T. cruzi antigens. Our findings provide new insights into immunotherapeutic strategies for people living with HIV/AIDS and Chagas disease.

Micro-management: curbing chronic wound infection.

PubMed

Withycombe, C; Purdy, K J; Maddocks, S E

2017-08-01

Chronic wounds, including pressure ulcers, foot ulcers, and venous leg ulcers, have a detrimental impact on the health and well-being of an estimated 2% of people in the UK. Chronic wounds are normally colonized by bacteria and in some instances bacterial load increases sufficiently for infection to ensue. Once a chronic wound becomes infected it is difficult to resolve and a combination of continuous inflammation and bacterial proliferation makes these wounds difficult to manage. A state of prolonged inflammation can occur as a result of impaired homeostatic pathways, which are exacerbated by bacterial growth. Chronic, infected wounds can persist for many months or even years, sometimes requiring surgical intervention in the form of regular debridement or amputation when other strategies such as antimicrobial treatments fail. The complex relationships between both oral microbiota and the host have been extensively characterized, including the shift from health to disease, and this has allowed the development of numerous control strategies. This knowledge, combined with contemporary studies of chronic infected wounds, can be used to develop an understanding of the relationship between the host and microorganism in the chronic wound environment. Such information has the potential to inform wound management including strategies to control infection and promote wound healing. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Immunovirological analyses of chronically simian immunodeficiency virus SIVmnd-1- and SIVmnd-2-infected mandrills (Mandrillus sphinx).

PubMed

Apetrei, Cristian; Sumpter, Beth; Souquiere, Sandrine; Chahroudi, Ann; Makuwa, Maria; Reed, Patricia; Ribeiro, Ruy M; Pandrea, Ivona; Roques, Pierre; Silvestri, Guido

2011-12-01

Simian immunodeficiency virus (SIV) infection in African nonhuman primate (NHP) natural hosts is usually nonpathogenic, despite high levels of virus replication. We have previously shown that chronic SIV infection in sooty mangabeys (SMs) and African green monkeys (AGMs) is associated with low levels of immune activation and bystander T cell apoptosis. To compare these features with those observed in another natural host, the mandrill (MND), we conducted a cross-sectional survey of the 23 SIV-infected and 25 uninfected MNDs from the only semifree colony of mandrills available worldwide. Viral loads (VLs) were determined and phenotypic and functional analysis of peripheral blood- and lymph node-derived lymphocytes was performed. We found that mandrills chronically infected with SIVmnd-1 or SIVmnd-2 have similar levels of viral replication, and we observed a trend toward lower CD4+ T cell counts in chronically SIVmnd-2-infected MNDs than SIVmnd-1-infected MNDs. No correlation between CD4+ T cell counts and VLs in SIV-infected MNDs could be established. Of note, the levels of T cell activation, proliferation, and apoptosis were comparable between SIVmnd-1- and SIVmnd-2-infected MNDs and to those observed in uninfected animals, with the only exception being an increase in tumor necrosis factor alpha-producing CD8+ T cells in SIVmnd-2-infected MNDs. Overall, these findings recapitulate previous observations in SIV-infected SMs and AGMs and lend further evidence to the hypothesis that low levels of immune activation protect natural SIV hosts from disease progression.

Progressive CD4+ central memory T cell decline results in CD4+ effector memory insufficiency and overt disease in chronic SIV infection.

PubMed

Okoye, Afam; Meier-Schellersheim, Martin; Brenchley, Jason M; Hagen, Shoko I; Walker, Joshua M; Rohankhedkar, Mukta; Lum, Richard; Edgar, John B; Planer, Shannon L; Legasse, Alfred; Sylwester, Andrew W; Piatak, Michael; Lifson, Jeffrey D; Maino, Vernon C; Sodora, Donald L; Douek, Daniel C; Axthelm, Michael K; Grossman, Zvi; Picker, Louis J

2007-09-03

Primary simian immunodeficiency virus (SIV) infections of rhesus macaques result in the dramatic depletion of CD4(+) CCR5(+) effector-memory T (T(EM)) cells from extra-lymphoid effector sites, but in most infections, an increased rate of CD4(+) memory T cell proliferation appears to prevent collapse of effector site CD4(+) T(EM) cell populations and acute-phase AIDS. Eventually, persistent SIV replication results in chronic-phase AIDS, but the responsible mechanisms remain controversial. Here, we demonstrate that in the chronic phase of progressive SIV infection, effector site CD4(+) T(EM) cell populations manifest a slow, continuous decline, and that the degree of this depletion remains a highly significant correlate of late-onset AIDS. We further show that due to persistent immune activation, effector site CD4(+) T(EM) cells are predominantly short-lived, and that their homeostasis is strikingly dependent on the production of new CD4(+) T(EM) cells from central-memory T (T(CM)) cell precursors. The instability of effector site CD4(+) T(EM) cell populations over time was not explained by increasing destruction of these cells, but rather was attributable to progressive reduction in their production, secondary to decreasing numbers of CCR5(-) CD4(+) T(CM) cells. These data suggest that although CD4(+) T(EM) cell depletion is a proximate mechanism of immunodeficiency, the tempo of this depletion and the timing of disease onset are largely determined by destruction, failing production, and gradual decline of CD4(+) T(CM) cells.

Bystander hyperactivation of preimmune CD8+ T cells in chronic HCV patients

PubMed Central

Alanio, Cécile; Nicoli, Francesco; Sultanik, Philippe; Flecken, Tobias; Perot, Brieuc; Duffy, Darragh; Bianchi, Elisabetta; Lim, Annick; Clave, Emmanuel; van Buuren, Marit M; Schnuriger, Aurélie; Johnsson, Kerstin; Boussier, Jeremy; Garbarg-Chenon, Antoine; Bousquet, Laurence; Mottez, Estelle; Schumacher, Ton N; Toubert, Antoine; Appay, Victor; Heshmati, Farhad; Thimme, Robert; Pol, Stanislas; Mallet, Vincent; Albert, Matthew L

2015-01-01

Chronic infection perturbs immune homeostasis. While prior studies have reported dysregulation of effector and memory cells, little is known about the effects on naïve T cell populations. We performed a cross-sectional study of chronic hepatitis C (cHCV) patients using tetramer-associated magnetic enrichment to study antigen-specific inexperienced CD8+ T cells (i.e., tumor or unrelated virus-specific populations in tumor-free and sero-negative individuals). cHCV showed normal precursor frequencies, but increased proportions of memory-phenotype inexperienced cells, as compared to healthy donors or cured HCV patients. These observations could be explained by low surface expression of CD5, a negative regulator of TCR signaling. Accordingly, we demonstrated TCR hyperactivation and generation of potent CD8+ T cell responses from the altered T cell repertoire of cHCV patients. In sum, we provide the first evidence that naïve CD8+ T cells are dysregulated during cHCV infection, and establish a new mechanism of immune perturbation secondary to chronic infection. DOI: http://dx.doi.org/10.7554/eLife.07916.001 PMID:26568315

Resistance of human plasmacytoid dendritic CAL-1 cells to infection with lymphocytic choriomeningitis virus (LCMV) is caused by restricted virus cell entry, which is overcome by contact of CAL-1 cells with LCMV-infected cells.

PubMed

Iwasaki, Masaharu; Sharma, Siddhartha M; Marro, Brett S; de la Torre, Juan C

2017-11-01

Plasmacytoid dendritic cells (pDCs), a main source of type I interferon in response to viral infection, are an early cell target during lymphocytic choriomeningitis virus (LCMV) infection, which has been associated with the LCMV's ability to establish chronic infections. Human blood-derived pDCs have been reported to be refractory to ex vivo LCMV infection. In the present study we show that human pDC CAL-1 cells are refractory to infection with cell-free LCMV, but highly susceptible to infection with recombinant LCMVs carrying the surface glycoprotein of VSV, indicating that LCMV infection of CAL-1 cells is restricted at the cell entry step. Co-culture of uninfected CAL-1 cells with LCMV-infected HEK293 cells enabled LCMV to infect CAL-1 cells. This cell-to-cell spread required direct cell-cell contact and did not involve exosome pathway. Our findings indicate the presence of a novel entry pathway utilized by LCMV to infect pDC. Copyright © 2017. Published by Elsevier Inc.

Successful reduced-intensity stem cell transplantation with cord blood for a poor-prognosis adult with refractory chronic active epstein-barr virus infection.

PubMed

Nakagawa, Masao; Hashino, Satoshi; Takahata, Mutsumi; Kawamura, Takahito; Fujisawa, Fumie; Kahata, Kaoru; Kondo, Takeshi; Imamura, Masahiro; Ando, Sachiko; Asaka, Masahiro

2007-06-01

A 56-year-old woman with a poor-prognosis chronic active Epstein-Barr virus (CAEBV) infection underwent reduced-intensity stem cell transplantation (RIST) using cryopreserved cord blood (CB). Administration of EBV-seronegative CB cells following a reduced-intensity conditioning regimen was effective and well tolerated. Complete remission with no symptoms, low titers of EBV-related antibodies, and an undetectable level of EBV DNA in peripheral blood mononuclear cells continued for 16 months after RIST. This report is the first of successful RIST with CB for an adult with CAEBV infection. The results also show that a graft-versus-CAEBV effect can be achieved in an allogeneic hematopoietic stem cell transplantation setting.

Memory vs memory-like: The different facets of CD8+ T-cell memory in HCV infection.

PubMed

Hofmann, Maike; Wieland, Dominik; Pircher, Hanspeter; Thimme, Robert

2018-05-01

Memory CD8 + T cells are essential in orchestrating protection from re-infection. Hallmarks of virus-specific memory CD8 + T cells are the capacity to mount recall responses with rapid induction of effector cell function and antigen-independent survival. Growing evidence reveals that even chronic infection does not preclude virus-specific CD8 + T-cell memory formation. However, whether this kind of CD8 + T-cell memory that is established during chronic infection is indeed functional and provides protection from re-infection is still unclear. Human chronic hepatitis C virus infection represents a unique model system to study virus-specific CD8 + T-cell memory formation during and after cessation of persisting antigen stimulation. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Behavior of soluble L-selectin in HIV infected children].

PubMed

Gaddi, E; Balbaryski, J; Cantisano, C; Barboni, G; Candi, M; Quiroz, H; Giraudi, V

2001-01-01

L-selectin is an adhesion molecule that is responsible for the initial attachment of leukocytes to endothelium. After leukocyte activation L-selectin is endoproteolytically released from the cell surface. In order to analyze the relationship between soluble L-selectin (sL-selectin) and parameters of immune activation and disease progression, 51 HIV infected children and 15 healthy controls were studied. Serum L-selectin concentrations were significantly higher in HIV infected children than in the control group. Levels of sL-selectin were higher in HIV infected patients with severe immunologic suppression than in those with moderate or no evidence of suppression. A positive correlation between sL-selectin levels and LTCD8 counts, sL-selectin and soluble intercellular adhesion molecule-1 (sICAM-1) and immunogobulin A (IgA) levels was detected. On the contrary sL-selectin concentration did not correlate with plasmatic viral load. The correlation with parameters of immune activation may implicate involvement of sL-selectin in the immunopathogenesis of HIV infection.

Chronic prostatic infection and inflammation by Propionibacterium acnes in a rat prostate infection model.

PubMed

Olsson, Jan; Drott, Johanna Bergh; Laurantzon, Lovisa; Laurantzon, Oscar; Bergh, Anders; Elgh, Fredrik

2012-01-01

Chronic inflammation in the prostate, seen as infiltration of inflammatory cells into the prostate gland in histological samples, affects approximately half the male population without indication of prostate disease, and is almost ubiquitous in patients diagnosed with benign prostate hyperplasia and cancer. Several studies have demonstrated the gram-positive bacterium Propionibacterium acnes to be frequently present in prostate tissue from men suffering from prostate disease. P. acnes has been shown to be associated with histological inflammation in human prostatectomy specimens, and also to induce strong inflammatory response in prostate-derived tissue culture models. The present paper describes a rat model for assessment of the pathogenic potential of P. acnes in prostate. Prostate glands of Sprague Dawley rats (n = 98) were exposed via an abdominal incision and live P. acnes or, in control rats, saline were injected into the ventral and dorso-lateral lobes. Rats were sacrificed 5 days, 3 weeks, 3 months and 6 months post infection, and prostate tissue was analyzed for bacterial content and histological inflammation. Rat sera were assessed for levels of CRP and anti-P. acnes IgG. Live P. acnes could be recovered from the dorso-lateral lobes up to 3 months post infection, while the ventral lobes were cleared from bacteria at that time. In samples up to 3 months post infection, the dorso-lateral lobes exhibited intense focal inflammation. CRP and IgG levels were elevated throughout the span of the experiment, and reached maximum levels 3 weeks and 3 months post infection, respectively. We show that P. acnes have the potential to cause chronic infection in previously healthy prostate, and that the infection has potential to cause chronic histological inflammation in the infected tissue. The high prevalence of P. acnes in human prostate tissue calls for resolution of pathogenic details. The present rat model suggests that complications such as chronic

Chronic Prostatic Infection and Inflammation by Propionibacterium acnes in a Rat Prostate Infection Model

PubMed Central

Olsson, Jan; Drott, Johanna Bergh; Laurantzon, Lovisa; Laurantzon, Oscar; Bergh, Anders; Elgh, Fredrik

2012-01-01

Chronic inflammation in the prostate, seen as infiltration of inflammatory cells into the prostate gland in histological samples, affects approximately half the male population without indication of prostate disease, and is almost ubiquitous in patients diagnosed with benign prostate hyperplasia and cancer. Several studies have demonstrated the Gram-positive bacterium Propionibacterium acnes to be frequently present in prostate tissue from men suffering from prostate disease. P. acnes has been shown to be associated with histological inflammation in human prostatectomy specimens, and also to induce strong inflammatory response in prostate-derived tissue culture models. The present paper describes a rat model for assessment of the pathogenic potential of P. acnes in prostate. Prostate glands of Sprague Dawley rats (n = 98) were exposed via an abdominal incision and live P. acnes or, in control rats, saline were injected into the ventral and dorso-lateral lobes. Rats were sacrificed 5 days, 3 weeks, 3 months and 6 months post infection, and prostate tissue was analyzed for bacterial content and histological inflammation. Rat sera were assessed for levels of CRP and anti-P. acnes IgG. Live P. acnes could be recovered from the dorso-lateral lobes up to 3 months post infection, while the ventral lobes were cleared from bacteria at that time. In samples up to 3 months post infection, the dorso-lateral lobes exhibited intense focal inflammation. CRP and IgG levels were elevated throughout the span of the experiment, and reached maximum levels 3 weeks and 3 months post infection, respectively. We show that P. acnes have the potential to cause chronic infection in previously healthy prostate, and that the infection has potential to cause chronic histological inflammation in the infected tissue. The high prevalence of P. acnes in human prostate tissue calls for resolution of pathogenic details. The present rat model suggests that complications such as chronic

Lymphocyte and macrophage phenotypes in chronic hepatitis C infection. Correlation with disease activity.

PubMed Central

Khakoo, S. I.; Soni, P. N.; Savage, K.; Brown, D.; Dhillon, A. P.; Poulter, L. W.; Dusheiko, G. M.

1997-01-01

The pathogenesis of chronic hepatitis C and the mechanisms underlying progressive liver disease in patients with chronic hepatitis C infection are poorly understood. To demonstrate which inflammatory cells might be responsible for the necroinflammatory damage in chronic hepatitis C infection, we have correlated the phenotype of the intrahepatic lymphocytes and macrophages with histological activity in liver biopsy and explant specimens from 19 patients with chronic hepatitis C infection. In all stages of disease, more CD8+ than CD4+ lymphocytes were found. However, histologically active versus histologically mild hepatitis was associated with a trend toward greater parenchymal concentrations of CD4+ lymphocytes (0.71 +/- 0.27 per 10(4) microns 2 versus 0.35 +/- 0.15; not significant), significantly less parenchymal CD8+ lymphocytes (0.90 +/- 0.1 versus 1.70 +/- 0.3; t = 2.32, P = 0.03) and a greater parenchymal CD4/CD8 ratio (4.1 +/- 2.8 versus 0.91 +/- 0.3; t = 1.65, P = 0.07). No difference was found in the number of cells containing cytotoxic granules between the two groups. Greater numbers of CD4+ lymphocytes were found in liver biopsy specimens with little or no staining for hepatitis C virus antigen (1.47 +/- 0.88 versus 0.27 +/- 0.27; t = 2.28, P < 0.05). No significant differences were found in the macrophage subsets between the three stages of disease. Our data suggest that active histological disease in chronic hepatitis C infection may be associated with an increase in CD4+ lymphocytes and suggest that CD4+ T cells may play an important role in the hepatic injury in these patients. Images Figure 2 PMID:9060834

Isolated Lactobacillus chronic prosthetic knee infection.

PubMed

Bennett, David M; Shekhel, Tatyana; Radelet, Matt; Miller, Michael D

2014-01-01

Lactobacillus is a gram-positive rod bacteria found primarily in the gastrointestinal and female genital tracts. Prosthetic infections in implants are being increasingly reported. The authors present a case of a 58-year-old patient with Lactobacillus septic prosthetic knee joint infection. To the authors’ knowledge, this is the first reported case of chronic prosthetic knee infection with isolated Lactobacillus species. Lactobacillus has been most commonly implicated with bacteremia and endocarditis and rarely with pneumonia, meningitis, and endovascular infection, and a vast majority of the cases are reported in immunocompromised patients. In the current case, diabetes mellitus, hepatitis, malnutrition, anemia, and liver failure were comorbid conditions, placing the patient at increased risk of infection. The findings suggest that further case series are necessary to establish the significance of Lactobacillus as an etiologic agent in chronic low-virulence, and potentially vancomycin-resistant, prosthetic joint infection. The need also exists for further research aimed at the risk of prosthetic joint infection with oral intake of certain probiotic foods and supplements. The goal of this case report is to bring to light the potential of this organism to be a cause of subtle chronic prosthetic joint infection.

Synovial Calprotectin: An Inexpensive Biomarker to Exclude a Chronic Prosthetic Joint Infection.

PubMed

Wouthuyzen-Bakker, Marjan; Ploegmakers, Joris J W; Ottink, Karsten; Kampinga, Greetje A; Wagenmakers-Huizenga, Lucie; Jutte, Paul C; Kobold, Anneke C M

2018-04-01

To diagnose or exclude a chronic prosthetic joint infection (PJI) can be a clinical challenge. Therefore, sensitive and specific biomarkers are needed in the diagnostic work-up. Calprotectin is a protein with antimicrobial properties and is released by activated neutrophils, making it a specific marker for infection. Because of its low costs and ability to obtain a quantitative value as a point of care test, it is an attractive marker to use in clinical practice. In addition, the test is already used in routine care in most hospitals for other indications and therefore easy to implement. Between June 2015 and June 2017 we collected synovial fluid of all consecutive patients who underwent revision surgery of a prosthetic joint because of chronic pain with or without prosthetic loosening. Synovial calprotectin was measured using a lateral flow immunoassay. A PJI was defined by the diagnostic criteria described by the Musculoskeletal Infection Society. Fifty-two patients with chronic pain were included. A PJI was diagnosed in 15 of 52 (29%) patients. The median calprotectin in the PJI group was 859 mg/L (interquartile range 86-1707) vs 7 mg/L (interquartile range 3-25) in the control group (P < .001). With a cut-off value of 50 mg/L, synovial calprotectin showed a sensitivity, specificity, positive predictive value, and negative predictive value of 86.7%, 91.7%, 81.3%, and 94.4%, respectively. Synovial calprotectin is a useful and cheap biomarker to use in the diagnostic work-up of patients with chronic pain, especially to exclude a PJI prior to revision surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

CD8+ lymphocytes control viral replication in SIVmac239-infected rhesus macaques without decreasing the lifespan of productively infected cells.

PubMed

Klatt, Nichole R; Shudo, Emi; Ortiz, Alex M; Engram, Jessica C; Paiardini, Mirko; Lawson, Benton; Miller, Michael D; Else, James; Pandrea, Ivona; Estes, Jacob D; Apetrei, Cristian; Schmitz, Joern E; Ribeiro, Ruy M; Perelson, Alan S; Silvestri, Guido

2010-01-29

While CD8+ T cells are clearly important in controlling virus replication during HIV and SIV infections, the mechanisms underlying this antiviral effect remain poorly understood. In this study, we assessed the in vivo effect of CD8+ lymphocyte depletion on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques. We treated two groups of animals that were either CD8+ lymphocyte-depleted or controls with antiretroviral therapy, and used mathematical modeling to assess the lifespan of infected cells either in the presence or absence of CD8+ lymphocytes. We found that, in both early (day 57 post-SIV) and late (day 177 post-SIV) chronic SIV infection, depletion of CD8+ lymphocytes did not result in a measurable increase in the lifespan of either short- or long-lived productively infected cells in vivo. This result indicates that the presence of CD8+ lymphocytes does not result in a noticeably shorter lifespan of productively SIV-infected cells, and thus that direct cell killing is unlikely to be the main mechanism underlying the antiviral effect of CD8+ T cells in SIV-infected macaques with high virus replication.

CD8+ Lymphocytes Control Viral Replication in SIVmac239-Infected Rhesus Macaques without Decreasing the Lifespan of Productively Infected Cells

PubMed Central

Klatt, Nichole R.; Shudo, Emi; Ortiz, Alex M.; Engram, Jessica C.; Paiardini, Mirko; Lawson, Benton; Miller, Michael D.; Else, James; Pandrea, Ivona; Estes, Jacob D.; Apetrei, Cristian; Schmitz, Joern E.; Ribeiro, Ruy M.; Perelson, Alan S.; Silvestri, Guido

2010-01-01

While CD8+ T cells are clearly important in controlling virus replication during HIV and SIV infections, the mechanisms underlying this antiviral effect remain poorly understood. In this study, we assessed the in vivo effect of CD8+ lymphocyte depletion on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques. We treated two groups of animals that were either CD8+ lymphocyte-depleted or controls with antiretroviral therapy, and used mathematical modeling to assess the lifespan of infected cells either in the presence or absence of CD8+ lymphocytes. We found that, in both early (day 57 post-SIV) and late (day 177 post-SIV) chronic SIV infection, depletion of CD8+ lymphocytes did not result in a measurable increase in the lifespan of either short- or long-lived productively infected cells in vivo. This result indicates that the presence of CD8+ lymphocytes does not result in a noticeably shorter lifespan of productively SIV-infected cells, and thus that direct cell killing is unlikely to be the main mechanism underlying the antiviral effect of CD8+ T cells in SIV-infected macaques with high virus replication. PMID:20126441

Cloning of a long HIV-1 readthrough transcript and detection of an increased level of early growth response protein-1 (Egr-1) mRNA in chronically infected U937 cells.

PubMed

Dron, M; Hameau, L; Benboudjema, L; Guymarho, J; Cajean-Feroldi, C; Rizza, P; Godard, C; Jasmin, C; Tovey, M G; Lang, M C

1999-01-01

To identify the pathways involved in HIV-1 modification of cellular gene expression, chronically infected U937 cells were screened by mRNA differential display. A chimeric transcript consisting of the 3' end of the LTR of a HIV-1 provirus, followed by 3.7 kb of cellular RNA was identified suggesting that long readthrough transcription might be one of the mechanisms by which gene expression could be modified in individual infected cells. Such a phenomenon may also be the first step towards the potential transduction of cellular sequences. Furthermore, the mRNA encoding for the transcription factor Egr-1 was detected as an over-represented transcript in infected cells. Northern blot analysis confirmed the increase of Egr-1 mRNA content in both HIV-1 infected promonocytic U937 cells and T cell lines such as Jurkat and CEM. Interestingly a similar increase of Egr-1 mRNA has previously been reported to occur in HTLV-1 and HTLV-2 infected T cell lines. Despite the consistent increase in the level of Egr-1 mRNA, the amount of the encoded protein did not appear to be modified in HIV-1 infected cells, suggesting an increased turn over of the protein in chronically infected cells.

Comparative study of the anti-HIV activities of ascorbate and thiol-containing reducing agents in chronically HIV-infected cells.

PubMed

Harakeh, S; Jariwalla, R J

1991-12-01

To elucidate the action of vitamin C on pathogenic human retroviruses, we investigated and compared the effects of noncytoxic concentrations of ascorbic acid (AA), its calcium salt (Ca-ascorbate), and two thiol-based reducing agents [glutathione (GSH) and N-acetyl-L-cysteine (NAC)] against human immunodeficiency virus (HIV)-1 replication in chronically infected T lymphocytes. Ca-ascorbate reduced extracellular HIV reverse transcriptase (RT) activity by about the same magnitude as the equivalent dose of AA. Long-term experiments showed that continuous presence of ascorbate was necessary for HIV suppression. NAC (10 mmol/L) caused less than twofold inhibition of HIV RT and conferred a synergistic effect (approximately eightfold inhibition) when tested simultaneously with AA (0.426 mmol/L). In contrast, nonesterified GSH (less than or equal to 1.838 mmol/L) had no effect on RT concentrations and did not potentiate the anti-HIV effect of AA. These results further support the potent antiviral activity of ascorbate and suggest its therapeutic value in controlling HIV infection in combination with thiols.

Telomere Dynamics in Immune Senescence and Exhaustion Triggered by Chronic Viral Infection.

PubMed

Bellon, Marcia; Nicot, Christophe

2017-10-05

The progressive loss of immunological memory during aging correlates with a reduced proliferative capacity and shortened telomeres of T cells. Growing evidence suggests that this phenotype is recapitulated during chronic viral infection. The antigenic volume imposed by persistent and latent viruses exposes the immune system to unique challenges that lead to host T-cell exhaustion, characterized by impaired T-cell functions. These dysfunctional memory T cells lack telomerase, the protein capable of extending and stabilizing chromosome ends, imposing constraints on telomere dynamics. A deleterious consequence of this excessive telomere shortening is the premature induction of replicative senescence of viral-specific CD8+ memory T cells. While senescent cells are unable to expand, they can survive for extended periods of time and are more resistant to apoptotic signals. This review takes a closer look at T-cell exhaustion in chronic viruses known to cause human disease: Epstein-Barr virus (EBV), Hepatitis B/C/D virus (HBV/HCV/HDV), human herpesvirus 8 (HHV-8), human immunodeficiency virus (HIV), human T-cell leukemia virus type I (HTLV-I), human papillomavirus (HPV), herpes simplex virus-1/2(HSV-1/2), and Varicella-Zoster virus (VZV). Current literature linking T-cell exhaustion with critical telomere lengths and immune senescence are discussed. The concept that enduring antigen stimulation leads to T-cell exhaustion that favors telomere attrition and a cell fate marked by enhanced T-cell senescence appears to be a common endpoint to chronic viral infections.

An unusual renal manifestation of chronic HBV infection.

PubMed

Aravindan, Ananthakrishnapuram; Yong, Jim; Killingsworth, Murray; Strasser, Simone; Suranyi, Michael

2010-08-01

Hepatitis B viral infection is usually a self-limiting disease in immunocompetent individuals. Chronic infection can be seen in up to 5% of infected patients. Renal manifestations of chronic HBV infection are usually glomerular. We describe here an uncommon presentation of a patient with chronic HBV infection with very high viral load and rapidly progressive renal failure. Renal biopsy showed features of tubulointerstitial nephritis and tubular epithelial inclusion bodies suggestive of HBV infection. Entecavir treatment slowed down the progression of his renal disease. Tubulointerstitial nephritis should be considered as a part of the differential diagnosis in patients with HBV infection. Early antiviral treatment may halt the progression of renal disease.

Innate and adaptive immune response to chronic pulmonary infection of hyphae of Aspergillus fumigatus in a new murine model.

PubMed

Wang, Fengyuan; Zhang, Caiyun; Jiang, Yuan; Kou, Caixia; Kong, Qingtao; Long, Nanbiao; Lu, Ling; Sang, Hong

2017-10-01

The pathogenesis of chronic pulmonary aspergillosis (CPA) has seldom been studied due partly to a lack of animal models. Since hypha is the main morphology colonizing the airway in CPA, it's critical to study the immune reaction to chronic pulmonary infection of hyphae of Aspergillus fumigatus, which also has seldom been studied in vivo before. We established a novel murine model of chronic pulmonary infection of hyphae by challenging immunocompetent mice with tightly-structured hyphae balls intratracheally, and described the ensuing immunoreaction to hyphae and conidia, and the pathogenesis of CPA. Our experiment proved that the hyphae balls could induce a chronic pulmonary infection for 28 days with a considerable recrudescence at day 28 post-infection. Lungs infected with hyphae balls were remarkable for the many neutrophils and macrophages that flooded into airway lumens, with peribronchiolar infiltration of leukocytes. There was a transient increase of Th2 cells and Th17 cells at day 7 post-infection in the lung tissue. In contrast, lungs infected with conidia showed no peribronchiolar infiltration of leukocytes, but an influx of a great number of macrophages, and a much less number of neutrophils in the lumen. Besides, conidia activated the co-response of Th1, Th2 and Th17 cells with an increase of Treg cells in the lung tissue (quite different from most previous studies). We established a new murine model of chronic infection of hyphae to mimic the formation of CPA, and provide a new marker for different immune responses to hyphae and conidia.

Acute Viral Respiratory Infection Rapidly Induces a CD8+ T Cell Exhaustion-like Phenotype.

PubMed

Erickson, John J; Lu, Pengcheng; Wen, Sherry; Hastings, Andrew K; Gilchuk, Pavlo; Joyce, Sebastian; Shyr, Yu; Williams, John V

2015-11-01

Acute viral infections typically generate functional effector CD8(+) T cells (TCD8) that aid in pathogen clearance. However, during acute viral lower respiratory infection, lung TCD8 are functionally impaired and do not optimally control viral replication. T cells also become unresponsive to Ag during chronic infections and cancer via signaling by inhibitory receptors such as programmed cell death-1 (PD-1). PD-1 also contributes to TCD8 impairment during viral lower respiratory infection, but how it regulates TCD8 impairment and the connection between this state and T cell exhaustion during chronic infections are unknown. In this study, we show that PD-1 operates in a cell-intrinsic manner to impair lung TCD8. In light of this, we compared global gene expression profiles of impaired epitope-specific lung TCD8 to functional spleen TCD8 in the same human metapneumovirus-infected mice. These two populations differentially regulate hundreds of genes, including the upregulation of numerous inhibitory receptors by lung TCD8. We then compared the gene expression of TCD8 during human metapneumovirus infection to those in acute or chronic lymphocytic choriomeningitis virus infection. We find that the immunophenotype of lung TCD8 more closely resembles T cell exhaustion late into chronic infection than do functional effector T cells arising early in acute infection. Finally, we demonstrate that trafficking to the infected lung alone is insufficient for TCD8 impairment or inhibitory receptor upregulation, but that viral Ag-induced TCR signaling is also required. Our results indicate that viral Ag in infected lungs rapidly induces an exhaustion-like state in lung TCD8 characterized by progressive functional impairment and upregulation of numerous inhibitory receptors. Copyright © 2015 by The American Association of Immunologists, Inc.

Endocytic function is critical for influenza A virus infection via DC-SIGN and L-SIGN

PubMed Central

Gillespie, Leah; Roosendahl, Paula; Ng, Wy Ching; Brooks, Andrew G.; Reading, Patrick C.; Londrigan, Sarah L.

2016-01-01

The ubiquitous presence of cell-surface sialic acid (SIA) has complicated efforts to identify specific transmembrane glycoproteins that function as bone fide entry receptors for influenza A virus (IAV) infection. The C-type lectin receptors (CLRs) DC-SIGN (CD209) and L-SIGN (CD209L) enhance IAV infection however it is not known if they act as attachment factors, passing virions to other unknown receptors for virus entry, or as authentic entry receptors for CLR-mediated virus uptake and infection. Sialic acid-deficient Lec2 Chinese Hamster Ovary (CHO) cell lines were resistant to IAV infection whereas expression of DC-SIGN/L-SIGN restored susceptibility of Lec2 cells to pH- and dynamin-dependent infection. Moreover, Lec2 cells expressing endocytosis-defective DC-SIGN/L-SIGN retained capacity to bind IAV but showed reduced susceptibility to infection. These studies confirm that DC-SIGN and L-SIGN are authentic endocytic receptors for IAV entry and infection. PMID:26763587

Immunopathology of experimental Chagas' disease: binding of T cells to Trypanosoma cruzi-infected heart tissue.

PubMed Central

Mortatti, R C; Maia, L C; de Oliveira, A V; Munk, M E

1990-01-01

The immunopathology of Chagas' disease was studied in the experimental model of chronic infection in C57BL/10JT or mice. Sublethal infection with Trypanosoma cruzi, Y strain, induced specific antibodies and a delayed hypersensitivity response to parasite antigens. Mice developed chronic chagasic myocarditis but not skeletal muscle myositis. Binding of T cells to infected heart tissue was investigated during short-term cocultivation of lymphocytes with heart cryostat sections. T cells from infected mice and from normal controls bound equally to myocardium and liver sections from both infected and normal mice. A search in depth was attempted with cells heavily tagged with 99mTc. Labeled T cells from chagasic mice bound to both normal and infected myocardium slices. 99mTc-labeled T cells from controls gave the same binding values. Glass-adherent spleen cells behaved identically to T cells. Prior treatment of the tissue with serum from chronically infected mice did not increase the number of binding cells. Peritoneal macrophages tagged with 99mTc-sulfur colloid also bound to infected myocardium slices. The binding of macrophages was not changed by pretreatment of infected tissue with anti-T, cruzi antibodies. In short, this work did not detect any population of T cells or macrophages which could bind specifically to infected heart tissue to initiate an autoreactive process. Images PMID:2228230

Prebiotic Oligosaccharides Potentiate Host Protective Responses against L. Monocytogenes Infection

PubMed Central

Chen, Poyin; Huang, Bihua; Kong, Nguyet; Weimer, Bart C.

2017-01-01

Prebiotic oligosaccharides are used to modulate enteric pathogens and reduce pathogen shedding. The interactions with prebiotics that alter Listeria monocytogenes infection are not yet clearly delineated. L. monocytogenes cellular invasion requires a concerted manipulation of host epithelial cell membrane receptors to initiate internalization and infection often via receptor glycosylation. Bacterial interactions with host glycans are intimately involved in modulating cellular responses through signaling cascades at the membrane and in intracellular compartments. Characterizing the mechanisms underpinning these modulations is essential for predictive use of dietary prebiotics to diminish pathogen association. We demonstrated that human milk oligosaccharide (HMO) pretreatment of colonic epithelial cells (Caco-2) led to a 50% decrease in Listeria association, while Biomos pretreatment increased host association by 150%. L. monocytogenes-induced gene expression changes due to oligosaccharide pretreatment revealed global alterations in host signaling pathways that resulted in differential subcellular localization of L. monocytogenes during early infection. Ultimately, HMO pretreatment led to bacterial clearance in Caco-2 cells via induction of the unfolded protein response and eIF2 signaling, while Biomos pretreatment resulted in the induction of host autophagy and L. monocytogenes vacuolar escape earlier in the infection progression. This study demonstrates the capacity of prebiotic oligosaccharides to minimize infection through induction of host-intrinsic protective responses. PMID:29257110

Divergent kinetics of proliferating T cell subsets in simian immunodeficiency virus (SIV) infection: SIV eliminates the "first responder" CD4+ T cells in primary infection.

PubMed

Wang, Xiaolei; Xu, Huanbin; Pahar, Bapi; Lackner, Andrew A; Veazey, Ronald S

2013-06-01

Although increased lymphocyte turnover in chronic human immunodeficiency virus and simian immunodeficiency virus (SIV) infection has been reported in blood, there is little information on cell turnover in tissues, particularly in primary SIV infection. Here we examined the levels of proliferating T cell subsets in mucosal and peripheral lymphoid tissues of adult macaques throughout SIV infection. To specifically label cells in S-phase division, all animals were inoculated with bromodeoxyuridine 24 h prior to sampling. In healthy macaques, the highest levels of proliferating CD4(+) and CD8(+) T cells were in blood and, to a lesser extent, in spleen. Substantial percentages of proliferating cells were also found in intestinal tissues, including the jejunum, ileum, and colon, but very few proliferating cells were detected in lymph nodes (axillary and mesenteric). Moreover, essentially all proliferating T cells in uninfected animals coexpressed CD95 and many coexpressed CCR5 in the tissues examined. Confocal microscopy also demonstrated that proliferating cells were substantial viral target cells for SIV infection and viral replication. After acute SIV infection, percentages of proliferating CD4(+) and CD8(+) T cells were significantly higher in tissues of chronically infected macaques and macaques with AIDS than in those of the controls. Surprisingly, however, we found that proliferating CD4(+) T cells were selectively decreased in very early infection (8 to 10 days postinoculation [dpi]). In contrast, levels of proliferating CD8(+) T cells rapidly increased after SIV infection, peaked by 13 to 21 dpi, and thereafter remained significantly higher than those in the controls. Taken together, these findings suggest that SIV selectively infects and destroys dividing, nonspecific CD4(+) T cells in acute infection, resulting in homeostatic changes and perhaps continuing loss of replication capacity to respond to nonspecific and, later, SIV-specific antigens.

Interaction between Galectin-9/TIM-3 pathway and follicular helper CD4+ T cells contributes to viral persistence in chronic hepatitis C.

PubMed

Zhuo, Ya; Zhang, Yi-Fu; Wu, Hong-Jie; Qin, Lei; Wang, Yan-Ping; Liu, A-Min; Wang, Xin-Hong

2017-10-01

Both Galectin 9 (Gal-9)/T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) pathway and follicular helper CD4 + T (Tfh) cells play important roles in persistent hepatitis C virus (HCV) infection. Thus, we aimed to investigate the regulatory role of interaction between Gal-9/TIM-3 pathway and Tfh cells in chronic hepatitis C. A total of 44 chronic hepatitis C patients and 19 normal controls (NCs) were enrolled in this study. Purified CD4 + T cells were cultured by TIM-3 Fc protein, recombinant Gal-9, or IL-21 for 48h. TIM-3 expression, Tfh proportion, and IL-21 production was measured, respectively. The immunomodulatory role of Gal-9/TIM-3 and IL-21 was also investigated in HCV cell culture system in vitro. We found that the percentage corresponding to both TIM-3-positive and CXCR5 + ICOS + Tfh cells within CD4 + T cells, which correlated with HCV RNA replication, was significantly elevated in patients with chronic hepatitis C in comparison with those in NCs. Moreover, blockade of Gal-9/TIM-3 pathway by TIM-3 Fc protein increased Tfh cells proportion, IL-21 mRNA and protein expression within purified CD4 + T cells, while activation of Gal-9/TIM-3 signaling by Gal-9 stimulation decreased IL-21 production in both patients with chronic HCV infection and healthy individuals. Meanwhile, high concentrations (100 and 200ng/mL) of IL-21 stimulation also elevated TIM-3 expression on CD4 + T cells in chronic hepatitis C. Furthermore, TIM-3 blockage and IL-21 stimulation suppressed mRNA expressions of HCV-induced antiviral proteins (myxovirus resistance A and oligoadenylate synthetase) in Huh7.5 cells without affecting viral replication in HCV cell culture system. The interaction between Gal-9/TIM-3 pathway and Tfh cells contributed to viral persistent in chronic HCV infection, which might be pivotal for development of new therapeutic approaches for chronic hepatitis C. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Terbinafine-loaded wound dressing for chronic superficial fungal infections.

PubMed

Paskiabi, Farnoush Asghari; Bonakdar, Shahin; Shokrgozar, Mohammad Ali; Imani, Mohammad; Jahanshiri, Zahra; Shams-Ghahfarokhi, Masoomeh; Razzaghi-Abyaneh, Mehdi

2017-04-01

In spite of developing new drugs and modern formulations, the treatments of chronic fungal infections are still challenging. Fibrous wound dressings are new suggestions for the treatment of chronic superficial infections. In the present study, we formulated an antifungal agent, terbinafine hydrochloride (TFH), which is a hydrophobic drug, in wound dressings prepared by electrospun polycaprolactone, polycaprolactone/gelatin (50:50 w/w) and gelatin. To obtain more water-stable meshes, the preparations were treated by glutaraldehyde and their properties were determined before and after treatment. The morphology of fibrous meshes was observed by scanning electron microscopy. Drug loading efficiency and release rate were measured by high performance liquid chromatography (HPLC) and the release rate was monitored for 144h. Antifungal tests were performed on Trichophyton mentagrophytes, Aspergillus fumigatus and Candida albicans cultured on Muller-Hinton agar. The toxicity of the meshes was measured after 24h and 14days by MTT assay. Terbinafine loading of polycaprolactone/gelatin (50:50) was 100% and it released the highest amount of TFH too. In antifungal tests, all samples were able to hinderT. mentagrophytes and A. fumigatus but not C. albicans growth among them, polycaprolactone fibers made the largest inhibition zone. In MTT assay, none of prepared samples showed toxicity against L929 cells. Teken together, the prepared TFH-loaded PCL/gelatin electrospun meshes were able to release TFH slowly and in a steady state in time. With respect to no obvious cytotoxicity in MTT assay and stong antifungal activity toward T. mentagrophytesin vitro, these TFH-based meshes could be considered as potential candidates in clinical application as wound dressing for treatment of chronic dermatophytosis. Copyright © 2016 Elsevier B.V. All rights reserved.

NK Cells and Their Ability to Modulate T Cells during Virus Infections

PubMed Central

Cook, Kevin D.; Waggoner, Stephen N.; Whitmire, Jason K.

2014-01-01

Natural killer (NK) cells are important in protection against virus infections, and many viruses have evolved mechanisms to thwart NK cell activity. NK cells respond to inflammatory signals at an early stage of virus infection, resulting in proliferation, cytokine production, and cytolytic activity that can reduce virus loads. Moreover, the rapid kinetics of the NK cell response enables NK cells to influence other populations of innate immune cells, affect the inflammatory milieu, and guide adaptive immune responses to infection. Early NK cell interactions with other leukocytes can have long-lasting effects on the number and quality of memory T cells, as well as impact the exhaustion of T cells during chronic infections. The ability of NK cells to modulate T cell responses can be mediated through direct T-NK interactions, cytokine production, or indirectly through dendritic cells and other cell types. Herein, we summarize our current understanding of how NK cells interact with T cells, dendritic cells, B cells, and other cell types involved in adaptive immune responses to virus infection. We outline several mechanisms by which NK cells enhance or suppress adaptive immune response and long-lived immunological memory. PMID:25404045

Occult hepatitis B virus infection is not associated with disease progression of chronic hepatitis C virus infection.

PubMed

Cho, Junhyeon; Lee, Sang Soo; Choi, Yun Suk; Jeon, Yejoo; Chung, Jung Wha; Baeg, Joo Yeong; Si, Won Keun; Jang, Eun Sun; Kim, Jin-Wook; Jeong, Sook-Hyang

2016-11-14

To clarify the prevalence of occult hepatitis B virus (HBV) infection (OBI) and the association between OBI and liver disease progression, defined as development of liver cirrhosis or hepatocellular carcinoma (HCC), worsening of Child-Pugh class, or mortality in cases of chronic hepatitis C virus (HCV) infection. This prospective cohort study enrolled 174 patients with chronic HCV infection (chronic hepatitis, n = 83; cirrhosis, n = 47; HCC, n = 44), and evaluated disease progression during a mean follow-up of 38.7 mo. OBI was defined as HBV DNA positivity in 2 or more different viral genomic regions by nested polymerase chain reaction using 4 sets of primers in the S, C, P and X open reading frame of the HBV genome. The overall OBI prevalence in chronic HCV patients at enrollment was 18.4%, with 16.9%, 25.5% and 13.6% in the chronic hepatitis C, liver cirrhosis and HCC groups, respectively ( P = 0.845). During follow-up, 52 patients showed disease progression, which was independently associated with aspartate aminotransferase > 40 IU/L, Child-Pugh score and sustained virologic response (SVR), but not with OBI positivity. In 136 patients who were not in the SVR state during the study period, OBI positivity was associated with neither disease progression, nor HCC development. The prevalence of OBI in chronic HCV patients was 18.4%, and OBI was not associated with disease progression in South Koreans.

Epstein-Barr Virus Infection of Polarized Epithelial Cells via the Basolateral Surface by Memory B Cell-Mediated Transfer Infection

PubMed Central

Shannon-Lowe, Claire; Rowe, Martin

2011-01-01

Epstein Barr virus (EBV) exhibits a distinct tropism for both B cells and epithelial cells. The virus persists as a latent infection of memory B cells in healthy individuals, but a role for infection of normal epithelial is also likely. Infection of B cells is initiated by the interaction of the major EBV glycoprotein gp350 with CD21 on the B cell surface. Fusion is triggered by the interaction of the EBV glycoprotein, gp42 with HLA class II, and is thereafter mediated by the core fusion complex, gH/gL/gp42. In contrast, direct infection of CD21-negative epithelial cells is inefficient, but efficient infection can be achieved by a process called transfer infection. In this study, we characterise the molecular interactions involved in the three stages of transfer infection of epithelial cells: (i) CD21-mediated co-capping of EBV and integrins on B cells, and activation of the adhesion molecules, (ii) conjugate formation between EBV-loaded B cells and epithelial cells via the capped adhesion molecules, and (iii) interaction of EBV glycoproteins with epithelial cells, with subsequent fusion and uptake of virions. Infection of epithelial cells required the EBV gH and gL glycoproteins, but not gp42. Using an in vitro model of normal polarized epithelia, we demonstrated that polarization of the EBV receptor(s) and adhesion molecules restricted transfer infection to the basolateral surface. Furthermore, the adhesions between EBV-loaded B cells and the basolateral surface of epithelial cells included CD11b on the B cell interacting with heparan sulphate moieties of CD44v3 and LEEP-CAM on epithelial cells. Consequently, transfer infection was efficiently mediated via CD11b-positive memory B cells but not by CD11b–negative naïve B cells. Together, these findings have important implications for understanding the mechanisms of EBV infection of normal and pre-malignant epithelial cells in vivo. PMID:21573183

Divergent Kinetics of Proliferating T Cell Subsets in Simian Immunodeficiency Virus (SIV) Infection: SIV Eliminates the “First Responder” CD4+ T Cells in Primary Infection

PubMed Central

Wang, Xiaolei; Xu, Huanbin; Pahar, Bapi; Lackner, Andrew A.

2013-01-01

Although increased lymphocyte turnover in chronic human immunodeficiency virus and simian immunodeficiency virus (SIV) infection has been reported in blood, there is little information on cell turnover in tissues, particularly in primary SIV infection. Here we examined the levels of proliferating T cell subsets in mucosal and peripheral lymphoid tissues of adult macaques throughout SIV infection. To specifically label cells in S-phase division, all animals were inoculated with bromodeoxyuridine 24 h prior to sampling. In healthy macaques, the highest levels of proliferating CD4+ and CD8+ T cells were in blood and, to a lesser extent, in spleen. Substantial percentages of proliferating cells were also found in intestinal tissues, including the jejunum, ileum, and colon, but very few proliferating cells were detected in lymph nodes (axillary and mesenteric). Moreover, essentially all proliferating T cells in uninfected animals coexpressed CD95 and many coexpressed CCR5 in the tissues examined. Confocal microscopy also demonstrated that proliferating cells were substantial viral target cells for SIV infection and viral replication. After acute SIV infection, percentages of proliferating CD4+ and CD8+ T cells were significantly higher in tissues of chronically infected macaques and macaques with AIDS than in those of the controls. Surprisingly, however, we found that proliferating CD4+ T cells were selectively decreased in very early infection (8 to 10 days postinoculation [dpi]). In contrast, levels of proliferating CD8+ T cells rapidly increased after SIV infection, peaked by 13 to 21 dpi, and thereafter remained significantly higher than those in the controls. Taken together, these findings suggest that SIV selectively infects and destroys dividing, nonspecific CD4+ T cells in acute infection, resulting in homeostatic changes and perhaps continuing loss of replication capacity to respond to nonspecific and, later, SIV-specific antigens. PMID:23596288

The adipocyte as an important target cell for Trypanosoma cruzi infection.

PubMed

Combs, Terry P; Nagajyothi; Mukherjee, Shankar; de Almeida, Cecilia J G; Jelicks, Linda A; Schubert, William; Lin, Ying; Jayabalan, David S; Zhao, Dazhi; Braunstein, Vicki L; Landskroner-Eiger, Shira; Cordero, Aisha; Factor, Stephen M; Weiss, Louis M; Lisanti, Michael P; Tanowitz, Herbert B; Scherer, Philipp E

2005-06-24

Adipose tissue plays an active role in normal metabolic homeostasis as well as in the development of human disease. Beyond its obvious role as a depot for triglycerides, adipose tissue controls energy expenditure through secretion of several factors. Little attention has been given to the role of adipocytes in the pathogenesis of Chagas disease and the associated metabolic alterations. Our previous studies have indicated that hyperglycemia significantly increases parasitemia and mortality in mice infected with Trypanosoma cruzi. We determined the consequences of adipocyte infection in vitro and in vivo. Cultured 3T3-L1 adipocytes can be infected with high efficiency. Electron micrographs of infected cells revealed a large number of intracellular parasites that cluster around lipid droplets. Furthermore, infected adipocytes exhibited changes in expression levels of a number of different adipocyte-specific or adipocyte-enriched proteins. The adipocyte is therefore an important target cell during acute Chagas disease. Infection of adipocytes by T. cruzi profoundly influences the pattern of adipokines. During chronic infection, adipocytes may represent an important long-term reservoir for parasites from which relapse of infection can occur. We have demonstrated that acute infection has a unique metabolic profile with a high degree of local inflammation in adipose tissue, hypoadiponectinemia, hypoglycemia, and hypoinsulinemia but with relatively normal glucose disposal during an oral glucose tolerance test.

CXCL9 Is Important for Recruiting Immune T Cells into the Brain and Inducing an accumulation of the T Cells to the areas of tachyzoite proliferation to prevent reactivation of chronic cerebral infection with Toxoplasma gondii

USDA-ARS?s Scientific Manuscript database

T cells are required to maintain the latency of chronic infection with Toxoplasma gondii in the brain. In the present study, we examined the role of non-ELR (glutamic acid-leucine-arginine) CXC chemokine CXCL9 for T cell recruitment to prevent reactivation of infection with T. gondii. SCID mice were...

Clinical Predictors of Liver Fibrosis in Patients With Chronic Hepatitis B Virus Infection From Children to Adults.

PubMed

Wu, Jia-Feng; Song, Shih-Hsi; Lee, Chee-Seng; Chen, Huey-Ling; Ni, Yen-Hsuan; Hsu, Hong-Yuan; Wu, Tzee-Chung; Chang, Mei-Hwei

2018-04-11

This study aimed to elucidate predictors of liver fibrosis in patients with chronic hepatitis B virus (HBV) infection. Transient elastography was performed to define liver stiffness in 533 patients with chronic HBV infection (mean age ± standard deviation, 30.72 ± 0.57 years). Protein array was performed on serum samples and lysates of Huh7 cells transfected with HBV mutants; the results were confirmed by enzyme-linked immunosorbent assay. Single-nucleotide polymorphisms in the gene encoding interleukin 1β (IL-1β) were examined in patients with chronic HBV infection with and without liver fibrosis. Male sex, age ≥18 years, and serum α-fetoprotein level >3.6 ng/mL were independent predictors of a liver stiffness measurement of ≥7 kPa (P = .005, .019, and <.001, respectively). HBV e antigen (HBeAg)-negative hepatitis is associated with increased liver stiffness (P < .001). Elevation of the serum IL-1β level was demonstrated in subjects with liver fibrosis. IL-1β was upregulated in Huh7 cells transfected with HBV mutants associated with HBeAg-negative hepatitis. The AA genotype at rs16944 and the CC genotype at rs1143627 in the gene encoding IL-1β were associated with higher serum IL-1β levels and liver fibrosis. Male sex, age ≥18 years, elevated α-fetoprotein level, and HBeAg-negative hepatitis are risk factors for liver fibrosis. IL-1β is involved in the progression of liver fibrosis in subjects with HBeAg-negative hepatitis.

Allogeneic peripheral blood stem cell transplantation for the treatment of chronic active Epstein-Barr virus infection.

PubMed

Fujii, N; Takenaka, K; Hiraki, A; Maeda, Y; Ikeda, K; Shinagawa, K; Ashiba, A; Munemasa, M; Sunami, K; Hiramatsu, Y; Ishimaru, F; Niiya, K; Yoshino, T; Harada, M

2000-10-01

The prognosis of chronic active Epstein-Barr virus infection (CAEBV) is very poor. We describe a 24-year-old male with severe CAEBV who was treated with allogeneic peripheral blood stem cell transplantation (allo-PBSCT). On admission, EBER-1 in lymphocytes infiltrating the liver, EBV-DNA in peripheral blood mononuclear cells (PBMC) and monoclonal NK cell proliferation were confirmed. After unsuccessful chemotherapy, he received an allo-PBSCT from his HLA-identical sister. Although he died of pulmonary hemorrhage on day +19, EBV-DNA was undetectable by PCR in PBMC, and the post-mortem liver showed no EBER-1-positive lymphocytes. This experience suggests that EBV-positive lymphocytes in CAEBV may be eradicated by allo-PBSCT, thereby raising the possibility of a new treatment modality. Bone Marrow Transplantation (2000) 26, 805-808.

Antibody-independent mechanisms regulate the establishment of chronic Plasmodium infection

PubMed Central

Lin, Jingwen; Cunningham, Deirdre; Tumwine, Irene; Kushinga, Garikai; McLaughlin, Sarah; Spence, Philip; Böhme, Ulrike; Sanders, Mandy; Conteh, Solomon; Bushell, Ellen; Metcalf, Tom; Billker, Oliver; Duffy, Patrick E.; Newbold, Chris; Berriman, Matthew; Langhorne, Jean

2017-01-01

Malaria is caused by parasites of the genus Plasmodium. All human-infecting Plasmodium species can establish long-lasting chronic infections1–5, creating an infectious reservoir to sustain transmission1,6. It is widely accepted that maintenance of chronic infection involves evasion of adaptive immunity by antigenic variation7. However, genes involved in this process have been identified in only two of five human-infecting species: P. falciparum and P. knowlesi. Furthermore, little is understood about the early events in establishment of chronic infection in these species. Using a rodent model we demonstrate that only a minority of parasites from among the infecting population, expressing one of several clusters of virulence-associated pir genes, establishes a chronic infection. This process occurs in different species of parasite and in different hosts. Establishment of chronicity is independent of adaptive immunity and therefore different from the mechanism proposed for maintainance of chronic P. falciparum infections7–9. Furthermore, we show that the proportions of parasites expressing different types of pir genes regulate the time taken to establish a chronic infection. Since pir genes are common to most, if not all, species of Plasmodium10, this process may be a common way of regulating the establishment of chronic infections. PMID:28165471

Approach to chronic wound infections.

PubMed

Leaper, D; Assadian, O; Edmiston, C E

2015-08-01

Infection is the likeliest single cause of delayed healing in healing of chronic open wounds by secondary intention. If neglected it can progress from contamination to colonization and local infection through to systemic infection, sepsis and multiple organ dysfunction syndrome, and it can be life-threatening. Infection in chronic wounds is not as easy to define as in acute wounds, and is complicated by the presence of biofilms. There is, as yet, no diagnostic for biofilm presence, but it contributes to excessive inflammation - through excessive and prolonged stimulation of nitric oxide, inflammatory cytokines and free radicals - and activation of immune complexes and complement, leading to a delay in healing. Control of biofilm is a key part of chronic wound management. Maintenance debridement and use of topical antimicrobials (antiseptics) are more effective than antibiotics, which should be reserved for treating spreading local and systemic infection. The continuing rise of antimicrobial resistance to antibiotics should lead us to reserve their use for these indications, as no new effective antibiotics are in the research pipeline. Antiseptics are effective through many mechanisms of action, unlike antibiotics, which makes the development of resistance to them unlikely. There is little evidence to support the theoretical risk that antiseptics select resistant pathogens. However, the use of antiseptic dressings for preventing and managing biofilm and infection progression needs further research involving well-designed, randomized controlled trials. © 2015 British Association of Dermatologists.

The Role of Infected Cell Proliferation in the Clearance of Acute HBV Infection in Humans

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

Goyal, Ashish; Ribeiro, Ruy Miguel; Perelson, Alan S.

Around 90–95% of hepatitis B virus (HBV) infected adults do not progress to the chronic phase and, instead, recover naturally. The strengths of the cytolytic and non-cytolytic immune responses are key players that decide the fate of acute HBV infection. In addition, it has been hypothesized that proliferation of infected cells resulting in uninfected progeny and/or cytokine-mediated degradation of covalently closed circular DNA (cccDNA) leading to the cure of infected cells are two major mechanisms assisting the adaptive immune response in the clearance of acute HBV infection in humans. We employed fitting of mathematical models to human acute infection datamore » together with physiological constraints to investigate the role of these hypothesized mechanisms in the clearance of infection. Results suggest that cellular proliferation of infected cells resulting in two uninfected cells is required to minimize the destruction of the liver during the clearance of acute HBV infection. In contrast, we find that a cytokine-mediated cure of infected cells alone is insufficient to clear acute HBV infection. Lastly, our modeling indicates that HBV clearance without lethal loss of liver mass is associated with the production of two uninfected cells upon proliferation of an infected cell.« less

The Role of Infected Cell Proliferation in the Clearance of Acute HBV Infection in Humans

DOE PAGES

Goyal, Ashish; Ribeiro, Ruy Miguel; Perelson, Alan S.

2017-11-18

Around 90–95% of hepatitis B virus (HBV) infected adults do not progress to the chronic phase and, instead, recover naturally. The strengths of the cytolytic and non-cytolytic immune responses are key players that decide the fate of acute HBV infection. In addition, it has been hypothesized that proliferation of infected cells resulting in uninfected progeny and/or cytokine-mediated degradation of covalently closed circular DNA (cccDNA) leading to the cure of infected cells are two major mechanisms assisting the adaptive immune response in the clearance of acute HBV infection in humans. We employed fitting of mathematical models to human acute infection datamore » together with physiological constraints to investigate the role of these hypothesized mechanisms in the clearance of infection. Results suggest that cellular proliferation of infected cells resulting in two uninfected cells is required to minimize the destruction of the liver during the clearance of acute HBV infection. In contrast, we find that a cytokine-mediated cure of infected cells alone is insufficient to clear acute HBV infection. Lastly, our modeling indicates that HBV clearance without lethal loss of liver mass is associated with the production of two uninfected cells upon proliferation of an infected cell.« less

IL-35, a hallmark of immune-regulation in cancer progression, chronic infections and inflammatory diseases.

PubMed

Teymouri, Manouchehr; Pirro, Matteo; Fallarino, Francesca; Gargaro, Marco; Sahebkar, Amirhosein

2018-03-25

Cytokine members of the IL-12 family have attracted enormous attention in the last few years, with IL-35 being the one of the most attractive-suppressive cytokine. IL-35 is an important mediator of regulatory T cell function. Regulatory T cells play key roles in restoring immune homeostasis after facing challenges such as infection by specific pathogens. Moreover, a crucial role for regulatory T cell populations has been demonstrated in several physiological processes, including establishment of fetal-maternal tolerance, maintenance of self-tolerance and prevention of autoimmune diseases. However, a deleterious involvement of immune regulatory T cells has been documented in specific inhibition of immune responses against tumor cells, promotion of chronic infections and establishment of chronic inflammatory disorders. In this review, we attempt to shed light on the concept of immune-homoeostasis on the aforementioned issues, taking IL-35 as the hallmark of regulatory responses. The dilemma between immune-mediated cancer treatment and inflammation is discussed. Histopathological indications of chronic vs. acute infections are elaborated. Moreover, the evidence that IL-35 requires additional immune-regulatory cytokines, such as IL-10 and TGF-β, to induce effective and maximal anti-inflammatory effects suggest that immune-regulation requires multi-factorial analysis of many immune playmakers rather than a specific immune target. © 2018 UICC.

Sigma Factor SigB Is Crucial to Mediate Staphylococcus aureus Adaptation during Chronic Infections.

PubMed

Tuchscherr, Lorena; Bischoff, Markus; Lattar, Santiago M; Noto Llana, Mariangeles; Pförtner, Henrike; Niemann, Silke; Geraci, Jennifer; Van de Vyver, Hélène; Fraunholz, Martin J; Cheung, Ambrose L; Herrmann, Mathias; Völker, Uwe; Sordelli, Daniel O; Peters, Georg; Löffler, Bettina

2015-04-01

Staphylococcus aureus is a major human pathogen that causes a range of infections from acute invasive to chronic and difficult-to-treat. Infection strategies associated with persisting S. aureus infections are bacterial host cell invasion and the bacterial ability to dynamically change phenotypes from the aggressive wild-type to small colony variants (SCVs), which are adapted for intracellular long-term persistence. The underlying mechanisms of the bacterial switching and adaptation mechanisms appear to be very dynamic, but are largely unknown. Here, we analyzed the role and the crosstalk of the global S. aureus regulators agr, sarA and SigB by generating single, double and triple mutants, and testing them with proteome analysis and in different in vitro and in vivo infection models. We were able to demonstrate that SigB is the crucial factor for adaptation in chronic infections. During acute infection, the bacteria require the simultaneous action of the agr and sarA loci to defend against invading immune cells by causing inflammation and cytotoxicity and to escape from phagosomes in their host cells that enable them to settle an infection at high bacterial density. To persist intracellularly the bacteria subsequently need to silence agr and sarA. Indeed agr and sarA deletion mutants expressed a much lower number of virulence factors and could persist at high numbers intracellularly. SigB plays a crucial function to promote bacterial intracellular persistence. In fact, ΔsigB-mutants did not generate SCVs and were completely cleared by the host cells within a few days. In this study we identified SigB as an essential factor that enables the bacteria to switch from the highly aggressive phenotype that settles an acute infection to a silent SCV-phenotype that allows for long-term intracellular persistence. Consequently, the SigB-operon represents a possible target to develop preventive and therapeutic strategies against chronic and therapy-refractory infections.

Detection of Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, and Prevotella nigrescens in chronic endodontic infection.

PubMed

Tomazinho, Luiz Fernando; Avila-Campos, Mario J

2007-02-01

Black-pigmented anaerobic rods such as Prevotella spp. and Porphyromonas spp. are involved in the etiology and perpetuation of endodontic infections. The aim of this study was to evaluate the prevalence of these species in chronic endodontic infections by using culture and polymerase chain reaction (PCR) techniques. Samples of 100 patients with root canals displaying chronic endodontic infections were obtained by sterilized paper points. Bacterial identification was performed by using culture and PCR techniques. By culture, in 33% of the samples, P. intermedia-P. nigrescens (75.8%), P. gingivalis (27.3%), and P. endodontalis (9.1%) were identified, and by PCR 60% of the samples harbored P. nigrescens (43.3%), P. gingivalis (43.3%), P. intermedia (31.7%), and P. endodontalis (23.3%). The presence of these black-pigmented anaerobic rods alone or in association in chronic endodontic infections seems to be frequent. PCR is a very sensitive technique for detecting DNA from bacterial cells. Culturing is only able to reveal living bacteria and is less sensitive for the identification of low numbers of bacterial cells.

Chronic bystander infections and immunity to unrelated antigens

PubMed Central

Stelekati, Erietta; Wherry, E. John

2012-01-01

Chronic infections with persistent pathogens such as helminths, mycobacteria, Plasmodium and hepatitis viruses affect more than a third of the human population and are associated with increased susceptibility to other pathogens as well as reduced vaccine efficacy. Although these observations suggest an impact of chronic infections in modulating immunity to unrelated antigens, little is known regarding the underlying mechanisms. Here, we summarize evidence of the most prevalent infections affecting immunity to unrelated pathogens and vaccines, and discuss potential mechanisms of how different bystander chronic infections might impact immune responses. We suggest that bystander chronic infections affect different stages of host responses and may impact transmission of other pathogens, recognition and innate immune responses, priming and differentiation of adaptive effector responses, as well as the development and maintenance of immunological memory. Further understanding of the immunological effects of co-infection should provide opportunities to enhance vaccine efficacy and control infectious diseases. PMID:23084915

Adipose Tissue Is a Neglected Viral Reservoir and an Inflammatory Site during Chronic HIV and SIV Infection

PubMed Central

Damouche, Abderaouf; Huot, Nicolas; Dejucq-Rainsford, Nathalie; Satie, Anne-Pascale; Mélard, Adeline; David, Ludivine; Gommet, Céline; Ghosn, Jade; Noel, Nicolas; Pourcher, Guillaume; Martinez, Valérie; Benoist, Stéphane; Béréziat, Véronique; Cosma, Antonio; Favier, Benoit; Vaslin, Bruno; Rouzioux, Christine; Capeau, Jacqueline; Müller-Trutwin, Michaela; Dereuddre-Bosquet, Nathalie; Le Grand, Roger; Lambotte, Olivier; Bourgeois, Christine

2015-01-01

Two of the crucial aspects of human immunodeficiency virus (HIV) infection are (i) viral persistence in reservoirs (precluding viral eradication) and (ii) chronic inflammation (directly associated with all-cause morbidities in antiretroviral therapy (ART)-controlled HIV-infected patients). The objective of the present study was to assess the potential involvement of adipose tissue in these two aspects. Adipose tissue is composed of adipocytes and the stromal vascular fraction (SVF); the latter comprises immune cells such as CD4+ T cells and macrophages (both of which are important target cells for HIV). The inflammatory potential of adipose tissue has been extensively described in the context of obesity. During HIV infection, the inflammatory profile of adipose tissue has been revealed by the occurrence of lipodystrophies (primarily related to ART). Data on the impact of HIV on the SVF (especially in individuals not receiving ART) are scarce. We first analyzed the impact of simian immunodeficiency virus (SIV) infection on abdominal subcutaneous and visceral adipose tissues in SIVmac251 infected macaques and found that both adipocytes and adipose tissue immune cells were affected. The adipocyte density was elevated, and adipose tissue immune cells presented enhanced immune activation and/or inflammatory profiles. We detected cell-associated SIV DNA and RNA in the SVF and in sorted CD4+ T cells and macrophages from adipose tissue. We demonstrated that SVF cells (including CD4+ T cells) are infected in ART-controlled HIV-infected patients. Importantly, the production of HIV RNA was detected by in situ hybridization, and after the in vitro reactivation of sorted CD4+ T cells from adipose tissue. We thus identified adipose tissue as a crucial cofactor in both viral persistence and chronic immune activation/inflammation during HIV infection. These observations open up new therapeutic strategies for limiting the size of the viral reservoir and decreasing low-grade chronic

Effector CD8^+ T cells migrate via chemokine-enhanced generalized L'evy walks

NASA Astrophysics Data System (ADS)

Banigan, Edward; Harris, Tajie; Christian, David; Liu, Andrea; Hunter, Christopher

2012-02-01

Chemokines play a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. In order to understand the role of the chemokine CXCL10 during chronic infection by the parasite T. gondii, we analyze tracks of migrating CD8^+ T cells in brain tissue. Surprisingly, we find that T cell motility is not described by a Brownian walk, but instead is consistent with a generalized L'evy walk consisting of L'evy-distributed runs alternating with pauses of L'evy-distributed durations. According to our model, this enables T cells to find rare targets more than an order of magnitude more efficiently than Brownian random walkers. The chemokine CXCL10 increases the migration speed without changing the character of the walk statistics. Thus, CD8^+ T cells use an efficient search strategy to facilitate an effective immune response, and CXCL10 aids them in shortening the average time to find rare targets.

Detection of PR-39, a porcine host defence peptide, in different cell sub-linages in pigs infected with Actinobacillus pleuropneumoniae.

PubMed

Gabner, S; Egerbacher, M; Gasse, H; Hewicker-Trautwein, M; Höltig, D; Waldmann, K-H; Blecha, F; Saalmüller, A; Hennig-Pauka, I

2017-10-01

Innate immunity is critically important for the outcome of infection in many diseases. It was previously shown that cathelicidin PR-39, an important porcine multifunctional host defence peptide, is elevated in bronchoalveolar lavage fluid and respiratory tract tissue after experimental infection with Actinobacillus pleuropneumoniae (A.pp.). To date, neutrophil polymorphonuclear leukocytes (PMNs) are thought to be the only source of PR-39. The aim of this study was to further characterize PR-39⁺ cells and selected immune cell populations in lung tissue during the peracute (7-10 hours), acute (2 days), reconvalescent (7 days) and chronic (21 days) stages of experimental infection with A.pp. serotype 2. In total, six mock-infected control pigs and 12 infected pigs were examined. Using immunofluorescence double-labeling, antibodies against PR-39 were combined with antibodies against CD3 (T-cells), CD79 (B-cells), Iba1 (activated macrophages), TTF-1 (lung epithelial cells expressing surfactant proteins), macrophage/L1 protein and myeloperoxidase (MPO, cells of the myeloid linage). In the peracute and acute phases of infection, total PR-39⁺ cells and myeloid linage cells increased, whereas CD3⁺ cells and TTF-1⁺ cells decreased. Double labeling revealed that most Macrophage/L1 protein+ cells and to a lesser extent MPO⁺ cells co-expressed PR-39. In addition, few bronchial epithelial cells and type 2 alveolar epithelial cells (both identified with TTF-1) produced PR-39. Occasionally, CD3⁺ T cells expressing PR-39 were seen in infected animals. Taken together, this study identifies cell types, other than PMNs, in lungs of A.pp.-infected pigs that are capable of producing PR-39. In addition, these findings provide further insights into the dynamics of different immune cell populations during A.pp.-infection.

Foveolar cells phagocytose apoptotic neutrophils in chronic active Helicobacter pylori gastritis.

PubMed

Caruso, R A; Fedele, F; Di Bella, C; Mazzon, E; Rigoli, L

2012-11-01

The recognition and removal of apoptotic inflammatory cells by tissue macrophages and non-professional phagocytes, in a process called efferocytosis, is required for resolution of inflammation and is actively anti-inflammatory. We have previously demonstrated phagocytosis of apoptotic neutrophils by tumor cells in human gastric carcinoma, but to date, there have been no studies investigating this process in chronic active Helicobacter pylori gastritis. Biopsy specimens from 28 subjects with or without H. pylori infection and active inflammation were examined and graded according to the updated Sydney system. Light microscopy, electron microscopy, and Terminal Deoxynucleotidyltransferase-Mediated UTP End Labeling staining were used to identify apoptosis. H. pylori infection was detected by histology and by molecular assay in 16 out of 28 cases. DNA from paraffin-embedded gastric biopsies was amplified using primers specific for cagA, for the cag "empty site" as well as for the s and m alleles of vacA. The more virulent cagA-positive strains were found in five out of nine patients with chronic active gastritis. The vacA s1/m1 and s2/m1 genotypes were more common in nine patients with chronic active gastritis, while the vacA s2/m2 genotype was more frequent in seven patients with chronic inactive gastritis. Apoptotic neutrophils were also detected within the cytoplasmic vacuoles of the foveolar cells of nine cases with chronic active gastritis. Transmission electron micrographs revealed further apoptotic neutrophils within spacious phagosomes of foveolar cells in a similar manner to those described in late-phase efferocytosis both in vivo and in vitro. These new observations expand the morphological spectrum of gastritis in patients infected with more virulent H. pylori strains, compatible with an anti-inflammatory role for the gastric epithelial cells in their removal of apoptotic neutrophils during active chronic gastritis.

Sea buckthorn (Hippophae rhamnoides L.) oil protects against chronic stress-induced inhibitory function of natural killer cells in rats.

PubMed

Diandong, Hou; Feng, Gu; Zaifu, Liang; Helland, Timothy; Weixin, Fu; Liping, Cai

2016-03-01

Chronic stress can suppress natural killer (NK) cell activity; this may also be related to the effect of stress on the neuroendocrine-immune network. Sea buckthorn (SBT) (Hippophae rhamnoides L.) is a thorny nitrogen fixing deciduous shrub, native to both Europe and Asia. It has been used as a medicinal plant in Tibetan and Mongolian traditional medicines. SBT has multifarious medical properties, including anti-fatigue as well as immunoregulatory effects. This study reports the effects of SBT oil with regard to the cytotoxicity and quantity of NK cells in the blood of a chronic-stress rat model, in addition to its mechanisms on the neuroendocrine-immune network. These results show that SBT oil, given by gavage to rats with chronic stress, could increase the following: body weight, NK cell quantities, and cytotoxicity, as well as the expression of perforin and granzyme B. The results also show that SBT oil in rats with chronic stress could suppress cortisol, ACTH, IL-1β and TNF-α levels, in addition to increasing 5-HT and IFN-γ serum levels. This leads to suggest that SBT oil, in rats with chronic stress, can increase NK cell cytotoxicity by upregulating the expression of perforin and granzyme B, thus causing associated effects of SBT oil on the neuroendocrine-immune network. © The Author(s) 2015.

Sea buckthorn (Hippophae rhamnoides L.) oil protects against chronic stress-induced inhibitory function of natural killer cells in rats

PubMed Central

Diandong, Hou; Feng, Gu; Zaifu, Liang; Helland, Timothy; Weixin, Fu; Liping, Cai

2015-01-01

Chronic stress can suppress natural killer (NK) cell activity; this may also be related to the effect of stress on the neuroendocrine–immune network. Sea buckthorn (SBT) (Hippophae rhamnoides L.) is a thorny nitrogen fixing deciduous shrub, native to both Europe and Asia. It has been used as a medicinal plant in Tibetan and Mongolian traditional medicines. SBT has multifarious medical properties, including anti-fatigue as well as immunoregulatory effects. This study reports the effects of SBT oil with regard to the cytotoxicity and quantity of NK cells in the blood of a chronic-stress rat model, in addition to its mechanisms on the neuroendocrine–immune network. These results show that SBT oil, given by gavage to rats with chronic stress, could increase the following: body weight, NK cell quantities, and cytotoxicity, as well as the expression of perforin and granzyme B. The results also show that SBT oil in rats with chronic stress could suppress cortisol, ACTH, IL-1β and TNF-α levels, in addition to increasing 5-HT and IFN-γ serum levels. This leads to suggest that SBT oil, in rats with chronic stress, can increase NK cell cytotoxicity by upregulating the expression of perforin and granzyme B, thus causing associated effects of SBT oil on the neuroendocrine–immune network. PMID:26684638

Minocycline attenuates HIV-1 infection and suppresses chronic immune activation in humanized NOD/LtsZ-scidIL-2Rγnull mice

PubMed Central

Singh, Maneesh; Singh, Pratibha; Vaira, Dolores; Amand, Mathieu; Rahmouni, Souad; Moutschen, Michel

2014-01-01

More than a quarter of a century of research has established chronic immune activation and dysfunctional T cells as central features of chronic HIV infection and subsequent immunodeficiency. Consequently, the search for a new immunomodulatory therapy that could reduce immune activation and improve T-cell function has been increased. However, the lack of small animal models for in vivo HIV study has hampered progress. In the current study, we have investigated a model of cord blood haematopoietic progenitor cells (CB-HPCs) -transplanted humanized NOD/LtsZ-scidIL-2Rγnull mice in which progression of HIV infection is associated with widespread chronic immune activation and inflammation. Indeed, HIV infection in humanized NSG mice caused up-regulation of several T-cell immune activation markers such as CD38, HLA-DR, CD69 and co-receptor CCR5. T-cell exhaustion markers PD-1 and CTLA-4 were found to be significantly up-regulated on T cells. Moreover, increased plasmatic levels of lipopolysaccharide, sCD14 and interleukin-10 were also observed in infected mice. Treatment with minocycline resulted in a significant decrease of expression of cellular and plasma immune activation markers, inhibition of HIV replication and improved T-cell counts in HIV-infected humanized NSG mice. The study demonstrates that minocycline could be an effective, low-cost adjunctive treatment to regulate chronic immune activation and replication of HIV. PMID:24409837

Human innate lymphoid cells (ILCs) in filarial infections.

PubMed

Bonne-Année, S; Nutman, T B

2018-02-01

Filarial infections are characteristically chronic and can cause debilitating diseases governed by parasite-induced innate and adaptive immune responses. Filarial parasites traverse or establish niches in the skin (migrating infective larvae), in nonmucosal tissues (adult parasite niche) and in the blood or skin (circulating microfilariae) where they intersect with the host immune response. While several studies have demonstrated that filarial parasites and their antigens can modulate myeloid cells (monocyte, macrophage and dendritic cell subsets), T- and B-lymphocytes and skin resident cell populations, the role of innate lymphoid cells during filarial infections has only recently emerged. Despite the identification and characterization of innate lymphoid cells (ILCs) in murine helminth infections, little is actually known about the role of human ILCs during parasitic infections. The focus of this review will be to highlight the composition of ILCs in the skin, lymphatics and blood; where the host-parasite interaction is well-defined and to examine the role of ILCs during filarial infections. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Middle Ear Infection (Chronic Otitis Media) and Hearing Loss

MedlinePlus

... You Middle Ear Infection (Chronic Otitis Media) and Hearing Loss Middle Ear Infection (Chronic Otitis Media) and ... loss. How does otitis media affect a child’s hearing? All children with middle ear infection or fluid ...

The effect of Beauveria bassiana infection on cell mediated and humoral immune response in house fly, Musca domestica L.

PubMed

Mishra, Sapna; Kumar, Peeyush; Malik, Anushree

2015-10-01

Entomopathogenic fungi that manifest infections by overcoming insect's immune response could be a successful control agent for the house fly, Musca domestica L. which is a major domestic, medical, and veterinary pest. In this study, the immune response of house fly to Beauveria bassiana infection was investigated to reveal fundamental aspects of house fly hemocyte biology, such as hemocyte numbers and size, which is poorly understood. The total hemocyte counts (THCs) in B. bassiana-infected house fly showed an initial increase (from 6 to 9 h), followed by subsequent decrease (9 to 12 h) with increase in time of infection. The THCs was slightly greater in infected flies than the non-infected ones. Insight into relative hemocyte counts depicted a significant increase in prohemocyte (PR) and decrease in granulocyte (GR) in infected house flies compared to non-infected ones. The relative cell area of hemocyte cells showed a noticeable increase in PR and intermediate cells (ICs), while a considerable reduction was observed for plasmatocyte (PL) and GR. The considerable variation in relative cell number and cell area in the B. bassiana-infected house flies indicated stress development during infection. The present study highlights changes occurring during B. bassiana invasion to house fly leading to establishment of infection along with facilitation in understanding of basic hemocyte biology. The results of the study is expected to help in better understanding of house fly immune response during fungal infection, so as to assist production of more efficient mycoinsecticides for house fly control using B. bassiana.

Target cell cyclophilins facilitate human papillomavirus type 16 infection.

PubMed

Bienkowska-Haba, Malgorzata; Patel, Hetalkumar D; Sapp, Martin

2009-07-01

Following attachment to primary receptor heparan sulfate proteoglycans (HSPG), human papillomavirus type 16 (HPV16) particles undergo conformational changes affecting the major and minor capsid proteins, L1 and L2, respectively. This results in exposure of the L2 N-terminus, transfer to uptake receptors, and infectious internalization. Here, we report that target cell cyclophilins, peptidyl-prolyl cis/trans isomerases, are required for efficient HPV16 infection. Cell surface cyclophilin B (CyPB) facilitates conformational changes in capsid proteins, resulting in exposure of the L2 N-terminus. Inhibition of CyPB blocked HPV16 infection by inducing noninfectious internalization. Mutation of a putative CyP binding site present in HPV16 L2 yielded exposed L2 N-terminus in the absence of active CyP and bypassed the need for cell surface CyPB. However, this mutant was still sensitive to CyP inhibition and required CyP for completion of infection, probably after internalization. Taken together, these data suggest that CyP is required during two distinct steps of HPV16 infection. Identification of cell surface CyPB will facilitate the study of the complex events preceding internalization and adds a putative drug target for prevention of HPV-induced diseases.

Chronic Exposure to Type-I IFN under Lymphopenic Conditions Alters CD4 T Cell Homeostasis

PubMed Central

Le Saout, Cecile; Hasley, Rebecca B.; Imamichi, Hiromi; Tcheung, Lueng; Hu, Zonghui; Luckey, Megan A.; Park, Jung-Hyun; Durum, Scott K.; Smith, Mindy; Rupert, Adam W.; Sneller, Michael C.; Lane, H. Clifford; Catalfamo, Marta

2014-01-01

HIV infection and the associated chronic immune activation alter T cell homeostasis leading to CD4 T cell depletion and CD8 T cell expansion. The mechanisms behind these outcomes are not totally defined and only partially explained by the direct cytopathic effect of the virus. In this manuscript, we addressed the impact of lymphopenia and chronic exposure to IFN-α on T cell homeostasis. In a lymphopenic murine model, this interaction led to decreased CD4 counts and CD8 T cell expansion in association with an increase in the Signal Transducer and Activator of Transcription 1 (STAT1) levels resulting in enhanced CD4 T cell responsiveness to IFN-α. Thus, in the setting of HIV infection, chronic stimulation of this pathway could be detrimental for CD4 T cell homeostasis. PMID:24603698

Anti-soluble liver antigen (SLA) antibodies in chronic HCV infection.

PubMed

Vitozzi, Susana; Lapierre, Pascal; Djilali-Saiah, Idriss; Marceau, Gabriel; Beland, Kathie; Alvarez, Fernando

2004-05-01

Hepatitis C infection is associated with autoimmune disorders, such as the production of autoantibodies. Anti-LKM1 and anti-LC1, immunomarkers of type 2 autoimmune hepatitis, have been previously associated with a HCV infection. Anti-Soluble-Liver-Antigen autoantibodies (SLA) are specifically associated with type 1 and type 2 autoimmune hepatitis and more closely related to patients who relapse after steroid therapy. The recent molecular cloning of the soluble liver antigen provides the opportunity to develop more specific tests for the detection of antibodies against it. The aim of this work is to characterize anti-soluble-liver autoantibodies in sera from patients chronically infected by HCV. A recombinant cDNA from activated Jurkat cells coding for the full length tRNP(Ser)Sec/SLA antigen was obtained. ELISA, Western Blot and immunoprecipitation tests were developed and used to search for linear and conformational epitopes recognized by anti-SLA antibodies in sera from patients chronically infected by HCV. Anti-soluble liver antigen antibodies were found in sera from 10.4% of HCV-infected patients. The prevalence was significantly increased to 27% when anti-LKM1 was also present. Most anti-SLA reactivity was directed against conformational epitopes on the antigen. The means titers by ELISA were lower than those obtained in type 2 AIH. The result of autoantibody isotyping showed a subclass restriction to IgG1 and also IgG4. This study shows the presence of anti-SLA antibodies in approximately 10% of HCV infected patients. The prevalence of SLA autoantibodies in HCV infected patients increases when LKM1 autoantibodies are also present. The relationship between the prevalence of this characteristic autoimmune hepatitis autoantibody and the implication of an autoimmune phenomenon in the liver injury of patients chronically infected by HCV needs further investigation.

Recovery of antigen-specific T cell responses from dogs infected with Leishmania (L.) infantum by use of vaccine associated TLR-agonist adjuvant.

PubMed

Schaut, Robert G; Grinnage-Pulley, Tara L; Esch, Kevin J; Toepp, Angela J; Duthie, Malcolm S; Howard, Randall F; Reed, Steven G; Petersen, Christine A

2016-10-17

Visceral leishmaniasis (VL), caused by infection with the obligate intracellular protozoan parasite Leishmania infantum, is a fatal disease of dogs and humans. Protection against VL requires a T helper 1 (Th1) skewed CD4 + T response, but despite this knowledge, there are currently no approved-to-market vaccines for humans and only three veterinary-use vaccines globally. As VL progresses from asymptomatic to symptomatic, L. infantum-specific interferon gamma (IFNγ) driven-Th1 responses become dampened and a state of immune exhaustion established. T cell exhaustion and other immunoregulatory processes, starting during asymptomatic disease, are likely to hinder vaccine-induced responses if vaccine is administered to infected, but asymptomatic and seronegative, individuals. In this study we evaluated how immune exhaustion, shown previously by our group to worsen in concert with VL progression, effected the capacity of vaccine candidate antigen/toll-like receptor (TLR) agonist combinations to promote protective CD4 + T cell responses during progressive VL. In conjunction with Th1 responses, we also evaluated concomitant stimulation of immune-balanced IL-10 regulatory cytokine production by these vaccine products in progressive VL canine T cells. Vaccine antigen L111f in combination with TLR agonists significantly recovered CD4 + T cell IFNγ intracellular production in T cells from asymptomatic VL dogs. Vaccine antigen NS with TLR agonists significantly recovered CD4 + T cell production in both endemic control and VL dogs. Combinations of TLR agonists and vaccine antigens overcame L. infantum induced cellular exhaustion, allowing robust Th1 CD4 + T cell responses from symptomatic dogs that previously had dampened responses to antigen alone. Antigen-agonist adjuvants can be utilized to promote more robust vaccine responses from infected hosts in endemic areas where vaccination of asymptomatic, L. infantum-infected animals is likely. Copyright © 2016. Published by

Hepatitis C co-infection is associated with an increased risk of incident chronic kidney disease in HIV-infected patients initiating combination antiretroviral therapy.

PubMed

Rossi, Carmine; Raboud, Janet; Walmsley, Sharon; Cooper, Curtis; Antoniou, Tony; Burchell, Ann N; Hull, Mark; Chia, Jason; Hogg, Robert S; Moodie, Erica E M; Klein, Marina B

2017-04-04

Combination antiretroviral therapy (cART) has reduced mortality from AIDS-related illnesses and chronic comorbidities have become prevalent among HIV-infected patients. We examined the association between hepatitis C virus (HCV) co-infection and chronic kidney disease (CKD) among patients initiating modern antiretroviral therapy. Data were obtained from the Canadian HIV Observational Cohort for individuals initiating cART from 2000 to 2012. Incident CKD was defined as two consecutive serum creatinine-based estimated glomerular filtration (eGFR) measurements <60 mL/min/1.73m 2 obtained ≥3 months apart. CKD incidence rates after cART initiation were compared between HCV co-infected and HIV mono-infected patients. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression. We included 2595 HIV-infected patients with eGFR >60 mL/min/1.73m 2 at cART initiation, of which 19% were HCV co-infected. One hundred and fifty patients developed CKD during 10,903 person-years of follow-up (PYFU). The CKD incidence rate was higher among co-infected than HIV mono-infected patients (26.0 per 1000 PYFU vs. 10.7 per 1000 PYFU). After adjusting for demographics, virologic parameters and traditional CKD risk factors, HCV co-infection was associated with a significantly shorter time to incident CKD (HR 1.97; 95% CI: 1.33, 2.90). Additional factors associated with incident CKD were female sex, increasing age after 40 years, lower baseline eGFR below 100 mL/min/1.73m 2 , increasing HIV viral load and cumulative exposure to tenofovir and lopinavir. HCV co-infection was associated with an increased risk of incident CKD among HIV-infected patients initiating cART. HCV-HIV co-infected patients should be monitored for kidney disease and may benefit from available HCV treatments.

T Follicular Helper Cells and B Cell Dysfunction in Aging and HIV-1 Infection

PubMed Central

Pallikkuth, Suresh; de Armas, Lesley; Rinaldi, Stefano; Pahwa, Savita

2017-01-01

T follicular helper (Tfh) cells are a subset of CD4 T cells that provide critical signals to antigen-primed B cells in germinal centers to undergo proliferation, isotype switching, and somatic hypermutation to generate long-lived plasma cells and memory B cells during an immune response. The quantity and quality of Tfh cells therefore must be tightly controlled to prevent immune dysfunction in the form of autoimmunity and, on the other hand, immune deficiency. Both Tfh and B cell perturbations appear during HIV infection resulting in impaired antibody responses to vaccines such as seasonal trivalent influenza vaccine, also seen in biologic aging. Although many of the HIV-associated defects improve with antiretroviral therapy (ART), excess immune activation and antigen-specific B and T cell responses including Tfh function are still impaired in virologically controlled HIV-infected persons on ART. Interestingly, HIV infected individuals experience increased risk of age-associated pathologies. This review will discuss Tfh and B cell dysfunction in HIV infection and highlight the impact of chronic HIV infection and aging on Tfh–B cell interactions. PMID:29109730

T Follicular Helper Cells and B Cell Dysfunction in Aging and HIV-1 Infection.

PubMed

Pallikkuth, Suresh; de Armas, Lesley; Rinaldi, Stefano; Pahwa, Savita

2017-01-01

T follicular helper (Tfh) cells are a subset of CD4 T cells that provide critical signals to antigen-primed B cells in germinal centers to undergo proliferation, isotype switching, and somatic hypermutation to generate long-lived plasma cells and memory B cells during an immune response. The quantity and quality of Tfh cells therefore must be tightly controlled to prevent immune dysfunction in the form of autoimmunity and, on the other hand, immune deficiency. Both Tfh and B cell perturbations appear during HIV infection resulting in impaired antibody responses to vaccines such as seasonal trivalent influenza vaccine, also seen in biologic aging. Although many of the HIV-associated defects improve with antiretroviral therapy (ART), excess immune activation and antigen-specific B and T cell responses including Tfh function are still impaired in virologically controlled HIV-infected persons on ART. Interestingly, HIV infected individuals experience increased risk of age-associated pathologies. This review will discuss Tfh and B cell dysfunction in HIV infection and highlight the impact of chronic HIV infection and aging on Tfh-B cell interactions.

Hepatocyte-derived exosomes promote T follicular regulatory cell expansion during hepatitis C virus infection.

PubMed

Cobb, Dustin A; Kim, Ok-Kyung; Golden-Mason, Lucy; Rosen, Hugo R; Hahn, Young S

2018-01-01

Hepatitis C virus (HCV) is a global health concern that can cause severe liver disease, such as cirrhosis and hepatocellular carcinoma. Control of HCV requires vigorous T-cell responses, yet CD4 + T cells in chronic HCV patients are dysfunctional. T follicular regulatory (Tfr) cells are a subset of regulatory T cells that suppress T follicular helper (Tfh) cells and the generation of high affinity antibody-producing B cells. In this study, we examined the accumulation of Tfr cells in the liver compartment during chronic HCV infection and defined the cellular and molecular mechanisms underlying their expansion. Our analysis revealed a substantial population of Tfr cells in livers of chronic HCV patients that is absent in liver tissues from nonviral hepatitis or healthy subjects. Coculture of PBMCs from healthy subjects with HCV-infected hepatoma cells resulted in preferential expansion of circulating Tfr cells, leading to suppression of Tfh cells. Additionally, coculture of tonsillar cells with infected hepatoma cells lead to an expansion of germinal center Tfr. Notably, expansion was mediated by transforming growth factor beta (TGF-β)-containing exosomes released from HCV-infected hepatocytes given that blockade of exosome-associated TGF-β or inhibition of exosome release abrogated Tfr expansion. These results show that liver-derived exosomes play a pivotal role in the accumulation of Tfr cells, likely leading to suppression of Tfh responses in HCV-infected patients. Our study identifies a novel pathway in which HCV infection in hepatocytes exacerbates Tfr cell responses to subvert antiviral immunity. (Hepatology 2018;67:71-85). © 2017 by the American Association for the Study of Liver Diseases.

In vitro and in vivo antivirus activity of an anti-programmed death-ligand 1 (PD-L1) rat-bovine chimeric antibody against bovine leukemia virus infection.

PubMed

Nishimori, Asami; Konnai, Satoru; Okagawa, Tomohiro; Maekawa, Naoya; Ikebuchi, Ryoyo; Goto, Shinya; Sajiki, Yamato; Suzuki, Yasuhiko; Kohara, Junko; Ogasawara, Satoshi; Kato, Yukinari; Murata, Shiro; Ohashi, Kazuhiko

2017-01-01

Programmed death-1 (PD-1), an immunoinhibitory receptor on T cells, is known to be involved in immune evasion through its binding to PD-ligand 1 (PD-L1) in many chronic diseases. We previously found that PD-L1 expression was upregulated in cattle infected with bovine leukemia virus (BLV) and that an antibody that blocked the PD-1/PD-L1 interaction reactivated T-cell function in vitro. Therefore, this study assessed its antivirus activities in vivo. First, we inoculated the anti-bovine PD-L1 rat monoclonal antibody 4G12 into a BLV-infected cow. However, this did not induce T-cell proliferation or reduction of BLV provirus loads during the test period, and only bound to circulating IgM+ B cells until one week post-inoculation. We hypothesized that this lack of in vivo effects was due to its lower stability in cattle and so established an anti-PD-L1 rat-bovine chimeric antibody (Boch4G12). Boch4G12 was able to bind specifically with bovine PD-L1, interrupt the PD-1/PD-L1 interaction, and activate the immune response in both healthy and BLV-infected cattle in vitro. Therefore, we experimentally infected a healthy calf with BLV and inoculated it intravenously with 1 mg/kg of Boch4G12 once it reached the aleukemic (AL) stage. Cultivation of peripheral blood mononuclear cells (PBMCs) isolated from the tested calf indicated that the proliferation of CD4+ T cells was increased by Boch4G12 inoculation, while BLV provirus loads were significantly reduced, clearly demonstrating that this treatment induced antivirus activities. Therefore, further studies using a large number of animals are required to support its efficacy for clinical application.

In vitro and in vivo antivirus activity of an anti-programmed death-ligand 1 (PD-L1) rat-bovine chimeric antibody against bovine leukemia virus infection

PubMed Central

Nishimori, Asami; Okagawa, Tomohiro; Maekawa, Naoya; Ikebuchi, Ryoyo; Goto, Shinya; Sajiki, Yamato; Suzuki, Yasuhiko; Kohara, Junko; Ogasawara, Satoshi; Kato, Yukinari; Murata, Shiro; Ohashi, Kazuhiko

2017-01-01

Programmed death-1 (PD-1), an immunoinhibitory receptor on T cells, is known to be involved in immune evasion through its binding to PD-ligand 1 (PD-L1) in many chronic diseases. We previously found that PD-L1 expression was upregulated in cattle infected with bovine leukemia virus (BLV) and that an antibody that blocked the PD-1/PD-L1 interaction reactivated T-cell function in vitro. Therefore, this study assessed its antivirus activities in vivo. First, we inoculated the anti-bovine PD-L1 rat monoclonal antibody 4G12 into a BLV-infected cow. However, this did not induce T-cell proliferation or reduction of BLV provirus loads during the test period, and only bound to circulating IgM+ B cells until one week post-inoculation. We hypothesized that this lack of in vivo effects was due to its lower stability in cattle and so established an anti-PD-L1 rat-bovine chimeric antibody (Boch4G12). Boch4G12 was able to bind specifically with bovine PD-L1, interrupt the PD-1/PD-L1 interaction, and activate the immune response in both healthy and BLV-infected cattle in vitro. Therefore, we experimentally infected a healthy calf with BLV and inoculated it intravenously with 1 mg/kg of Boch4G12 once it reached the aleukemic (AL) stage. Cultivation of peripheral blood mononuclear cells (PBMCs) isolated from the tested calf indicated that the proliferation of CD4+ T cells was increased by Boch4G12 inoculation, while BLV provirus loads were significantly reduced, clearly demonstrating that this treatment induced antivirus activities. Therefore, further studies using a large number of animals are required to support its efficacy for clinical application. PMID:28445479

Clinical and virological characteristics of 15 patients with chronic active Epstein-Barr virus infection treated with hematopoietic stem cell transplantation.

PubMed

Gotoh, Kensei; Ito, Yoshinori; Shibata-Watanabe, Yukiko; Kawada, Jun-ichi; Takahashi, Yoshiyuki; Yagasaki, Hiroshi; Kojima, Seiji; Nishiyama, Yukihiro; Kimura, Hiroshi

2008-05-15

Chronic active Epstein-Barr virus (EBV) infection is characterized by recurrent infectious mononucleosis-like symptoms, and infected patients have high viral loads in their peripheral blood. Standard therapy for the disease has not yet been established. Recently, hematopoietic stem cell transplantation (HSCT) has been introduced and has the potential to become a standard treatment, although guidelines for HSCT to treat chronic active EBV infection have not yet been proposed. Fifteen patients were retrospectively analyzed, both clinically and virologically, to investigate the factors associated with prognosis of chronic active EBV infection treated with HSCT. After HSCT, 7 patients died after survival periods that ranged from 1 to 16 months (mean duration of survival after HSCT, 5 months). Three patients were considered to have died of transplantation-related complications. The duration between infection onset and diagnosis was significantly longer in patients who died than in those who survived. Five of the 7 patients who died experienced > or =3 life-threatening complications. The plasma concentrations of interferon-gamma, interleukin-10, thrombomodulin, and soluble E-selectin did not differ significantly between the groups of patients. With regard to sequence variations in the EBV latent membrane protein 1 gene, no specific patterns were found in the patients who died. Importantly, the plasma EBV load at diagnosis was significantly higher in patients who died than in living patients. Moreover, plasma viral load was shown to be an important factor to monitor during follow-up for patients after HSCT. The number of life-threatening complications and plasma viral load are indicative of the stage of disease progression and may be useful factors for predicting the outcome of HSCT.

Successful treatment of natural killer (NK) cell leukemia following a long-standing chronic active Epstein-Barr virus (CAEBV) infection with allogeneic bone marrow transplantation.

PubMed

Ebihara, Y; Manabe, A; Tanaka, R; Yoshimasu, T; Ishikawa, K; Iseki, T; Hayakawa, J; Maeda, M; Asano, S; Tsuji, K

2003-06-01

The optimal treatment for natural killer (NK) cell leukemia after chronic active Epstein-Barr virus (CAEBV) infection has not been determined. A 15-year-old boy presented with NK cell leukemia following CAEBV infection for 5 years. The peripheral blood and BM had an increased number of CD3(-)CD56(+) large granular lymphocytes and a monoclonal integration of the EBV genome was detected. Chemotherapy was not sufficiently effective to control the disease. Allogeneic BMT from an HLA-identical sister was performed using a conditioning regimen consisting of total body irradiation, cyclophosphamide and thiotepa. The patient is disease-free with a perfect performance status 24 months after BMT. This is the first report to show that allogeneic BMT is potentially able to cure NK cell leukemia after CAEBV infection.

T-bet-mediated Tim-3 expression dampens monocyte function during chronic hepatitis C virus infection.

PubMed

Yi, Wenjing; Zhang, Peixin; Liang, Yan; Zhou, Yun; Shen, Huanjun; Fan, Chao; Moorman, Jonathan P; Yao, Zhi Q; Jia, Zhansheng; Zhang, Ying

2017-03-01

Hepatitis C virus (HCV) induces a high rate of chronic infection via dysregulation of host immunity. We have previously shown that T-cell immunoglobulin and mucin domain protein-3 (Tim-3) is up-regulated on monocyte/macrophages (M/Mφ) during chronic HCV infection; little is known, however, about the transcription factor that controls its expression in these cells. In this study, we investigated the role of transcription factor, T-box expressed in T cells (T-bet), in Tim-3 expression in M/Mφ in the setting of HCV infection. We demonstrate that T-bet is constitutively expressed in resting CD14 + M/Mφ in the peripheral blood. M/Mφ from chronically HCV-infected individuals exhibit a significant increase in T-bet expression that positively correlates with an increased level of Tim-3 expression. Up-regulation of T-bet is also observed in CD14 + M/Mφ incubated with HCV + Huh7.5 cells, as well as in primary M/Mφ or monocytic THP-1 cells exposed to HCV core protein in vitro, which is reversible by blocking HCV core/gC1qR interactions. Moreover, the HCV core-induced up-regulation of T-bet and Tim-3 expression in M/Mφ can be abrogated by incubating the cells with SP600125 - an inhibitor for the c-Jun N-terminal kinase (JNK) signalling pathway. Importantly, silencing T-bet gene expression decreases Tim-3 expression and enhances interleukin-12 secretion as well as signal transducer and activator of transcription 1 phosphorylation. These data suggest that T-bet, induced by the HCV core/gC1qR interaction, enhances Tim-3 expression via the JNK pathway, leading to dampened M/Mφ function during HCV infection. These findings reveal a novel mechanism for Tim-3 regulation via T-bet during HCV infection, providing new targets to combat this global epidemic viral disease. © 2016 John Wiley & Sons Ltd.

Establishment of Chronic Infection: Brucella's Stealth Strategy

PubMed Central

Ahmed, Waqas; Zheng, Ke; Liu, Zheng-Fei

2016-01-01

Brucella is a facultative intracellular pathogen that causes zoonotic infection known as brucellosis which results in abortion and infertility in natural host. Humans, especially in low income countries, can acquire infection by direct contact with infected animal or by consumption of animal products and show high morbidity, severe economic losses and public health problems. However for survival, host cells develop complex immune mechanisms to defeat and battle against attacking pathogens and maintain a balance between host resistance and Brucella virulence. On the other hand as a successful intracellular pathogen, Brucella has evolved multiple strategies to evade immune response mechanisms to establish persistent infection and replication within host. In this review, we mainly summarize the “Stealth” strategies employed by Brucella to modulate innate and the adaptive immune systems, autophagy, apoptosis and possible role of small noncoding RNA in the establishment of chronic infection. The purpose of this review is to give an overview for recent understanding how this pathogen evades immune response mechanisms of host, which will facilitate to understanding the pathogenesis of brucellosis and the development of novel, more effective therapeutic approaches to treat brucellosis. PMID:27014640

Listeria monocytogenes infection of HD11, chicken macrophage-like cells.

PubMed

Jarvis, N A; Donaldson, J R; O'Bryan, C A; Ricke, S C; Crandall, P G

2017-04-01

Listeria monocytogenes can be carried by and infect poultry, although the clinical disease in birds is rare. Escape from macrophage phagocytosis is a key step in pathogenesis for L. monocytogenes. Therefore, we investigated the infection of the chicken macrophage-like cell line HD11 with 2 strains of L. monocytogenes EGD-e and Scott A. After infection, L. monocytogenes was quantified by spread plating and HD11 was quantified with trypan blue exclusion stain before enumeration. The standard macrophage killing protocols require washing the cell monolayers 3 times with PBS, which was found to negatively influence HD11 monolayers. Maximum bacterial densities within macrophages were not different between the 2 Listeria strains. HD11 required more than 11 h to effectively reduce intracellular L. monocytogenes Scott A, and Scott A was more susceptible to HD11 killing than EGD-e. It appears that Listeria infection initially causes attenuation of HD11 growth, and infected HD11 cells do not begin to lyse until at least 11 h post infection. These results suggest that there are subtle strain to strain differences in response to HD11 macrophage phagocytosis. The long lead-time required for HD11 to kill L. monocytogenes cells means that there is sufficient time available for chicken macrophages to circulate in the blood and transfer the intracellular Listeria to multiple tissues. © 2016 Poultry Science Association Inc.

Dyslipidemia, chronic inflammation, and subclinical atherosclerosis in children and adolescents infected with HIV: The PositHIVe Health Study.

PubMed

Augustemak de Lima, Luiz Rodrigo; Petroski, Edio Luiz; Moreno, Yara Maria Franco; Silva, Diego Augusto Santos; Trindade, Erasmo Benício de Moraes Santos; Carvalho, Aroldo Prohmann de; Back, Isabela de Carlos

2018-01-01

HIV-infected children and adolescents may be at risk for cardiovascular disease due to chronic inflammation and exacerbation of risk factors. The aim of this study was as follows: 1) compare cardiovascular risk factors, chronic inflammation, and carotid intima-media thickness (IMTc) between the HIV and control groups; 2) determine the association of HIV and antiretroviral (ART) regimens with cardiovascular risk factors, chronic inflammation, and IMTc; and 3) identify variables associated with elevated IMTc. Cross-sectional analysis of 130 children and adolescents, 8-15 years of age, divided into HIV-infected (n = 65) and healthy control (n = 65) participants. Body fat, blood pressure, glycemia, insulin, and glycated hemoglobin, total cholesterol and fractions (LDL-C and HDL-C), triglycerides, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and the IMTc were measured. The results showed HIV-infected children and adolescents had higher levels of glycemia (87.9 vs. 75.9 mg.dL-1, p< 0.001), LDL-c (94.7 vs. 79.5 mg.dL-1, p = 0.010), triglycerides (101.2 vs. 61.6 mg.dL-1, p< 0.001), CRP (1.6 vs. 1.0 mg.L-1, p = 0.007), IL-6 (1.42 vs. 0.01 pg.mL-1, p< 0.001), TNF-α (0.49 vs. 0.01 pg.mL-1, p< 0.001), mean IMTc (0.526 vs. 0.499 mm, p = 0.009), and lower HDL-c (53.7 vs. 69.4 mg.dL-1, p< 0.001) compared to controls. Systolic blood pressure (β = 0.006, p = 0.004) and TNF-α (β = -0.033, p = 0.029) accounted for 16% of IMTc variability in HIV-infected children and adolescents. In patients using protease inhibitors-based ART, male gender (β = -0.186, p = 0.008), trunk body fat (β = -0.011, p = 0.006), glucose (β = 0.005, p = 0.046), and IL-6 (β = 0.017, p = 0.039) accounted for 28% of IMTc variability. HIV-infected children and adolescents may be at risk for premature atherosclerosis due to chronic inflammation and dyslipidemia. Interventions with the potential to improve lipid profile, mitigate inflammation, and reduce cardiovascular

Primary peak and chronic malaria infection levels are correlated in experimentally infected great reed warblers.

PubMed

Asghar, Muhammad; Westerdahl, Helena; Zehtindjiev, Pavel; Ilieva, Mihaela; Hasselquist, Dennis; Bensch, Staffan

2012-09-01

Malaria parasites often manage to maintain an infection for several months or years in their vertebrate hosts. In humans, rodents and birds, most of the fitness costs associated with malaria infections are in the short initial primary (high parasitaemia) phase of the infection, whereas the chronic phase (low parasitaemia) is more benign to the host. In wild birds, malaria parasites have mainly been studied during the chronic phase of the infection. This is because the initial primary phase of infection is short in duration and infected birds with severe disease symptoms tend to hide in sheltered places and are thus rarely caught and sampled. We therefore wanted to investigate the relationship between the parasitaemia during the primary and chronic phases of the infection using an experimental infection approach. We found a significant positive correlation between parasitaemia in the primary peak and the subsequent chronic phase of infection when we experimentally infected great reed warblers (Acrocephalus arundinaceus) with Plasmodium ashfordi. The reason for this association remains to be understood, but might arise from individual variation in exoerythrocytic parasite reservoirs in hosts, parasite antigenic diversity and/or host genetics. Our results suggest that the chronic phase parasitaemia can be used to qualitatively infer the parasitaemia of the preceding and more severe primary phase, which is a very important finding for studies of avian malaria in wild populations.

Loss of memory B cells impairs maintenance of long-term serologic memory during HIV-1 infection.

PubMed

Titanji, Kehmia; De Milito, Angelo; Cagigi, Alberto; Thorstensson, Rigmor; Grützmeier, Sven; Atlas, Ann; Hejdeman, Bo; Kroon, Frank P; Lopalco, Lucia; Nilsson, Anna; Chiodi, Francesca

2006-09-01

Circulating memory B cells are severely reduced in the peripheral blood of HIV-1-infected patients. We investigated whether dysfunctional serologic memory to non-HIV antigens is related to disease progression by evaluating the frequency of memory B cells, plasma IgG, plasma levels of antibodies to measles, and Streptococcus pneumoniae, and enumerating measles-specific antibody-secreting cells in patients with primary, chronic, and long-term nonprogressive HIV-1 infection. We also evaluated the in vitro production of IgM and IgG antibodies against measles and S pneumoniae antigens following polyclonal activation of peripheral blood mononuclear cells (PBMCs) from patients. The percentage of memory B cells correlated with CD4+ T-cell counts in patients, thus representing a marker of disease progression. While patients with primary and chronic infection had severe defects in serologic memory, long-term nonprogressors had memory B-cell frequency and levels of antigen-specific antibodies comparable with controls. We also evaluated the effect of antiretroviral therapy on these serologic memory defects and found that antiretroviral therapy did not restore serologic memory in primary or in chronic infection. We suggest that HIV infection impairs maintenance of long-term serologic immunity to HIV-1-unrelated antigens and this defect is initiated early in infection. This may have important consequences for the response of HIV-infected patients to immunizations.

Plasmacytoid Dendritic Cell Infection and Sensing Capacity during Pathogenic and Nonpathogenic Simian Immunodeficiency Virus Infection

PubMed Central

Jochems, Simon P.; Jacquelin, Beatrice; Chauveau, Lise; Huot, Nicolas; Petitjean, Gaël; Lepelley, Alice; Liovat, Anne-Sophie; Ploquin, Mickaël J.; Cartwright, Emily K.; Bosinger, Steven E.; Silvestri, Guido; Barré-Sinoussi, Françoise; Lebon, Pierre; Schwartz, Olivier

2015-01-01

ABSTRACT Human immunodeficiency virus (HIV) in humans and simian immunodeficiency virus (SIV) in macaques (MAC) lead to chronic inflammation and AIDS. Natural hosts, such as African green monkeys (AGM) and sooty mangabeys (SM), are protected against SIV-induced chronic inflammation and AIDS. Here, we report that AGM plasmacytoid dendritic cells (pDC) express extremely low levels of CD4, unlike MAC and human pDC. Despite this, AGM pDC efficiently sensed SIVagm, but not heterologous HIV/SIV isolates, indicating a virus-host adaptation. Moreover, both AGM and SM pDC were found to be, in contrast to MAC pDC, predominantly negative for CCR5. Despite such limited CD4 and CCR5 expression, lymphoid tissue pDC were infected to a degree similar to that seen with CD4+ T cells in both MAC and AGM. Altogether, our finding of efficient pDC infection by SIV in vivo identifies pDC as a potential viral reservoir in lymphoid tissues. We discovered low expression of CD4 on AGM pDC, which did not preclude efficient sensing of host-adapted viruses. Therefore, pDC infection and efficient sensing are not prerequisites for chronic inflammation. The high level of pDC infection by SIVagm suggests that if CCR5 paucity on immune cells is important for nonpathogenesis of natural hosts, it is possibly not due to its role as a coreceptor. IMPORTANCE The ability of certain key immune cell subsets to resist infection might contribute to the asymptomatic nature of simian immunodeficiency virus (SIV) infection in its natural hosts, such as African green monkeys (AGM) and sooty mangabeys (SM). This relative resistance to infection has been correlated with reduced expression of CD4 and/or CCR5. We show that plasmacytoid dendritic cells (pDC) of natural hosts display reduced CD4 and/or CCR5 expression, unlike macaque pDC. Surprisingly, this did not protect AGM pDC, as infection levels were similar to those found in MAC pDC. Furthermore, we show that AGM pDC did not consistently produce type I

Differential cellular targets of Epstein-Barr virus (EBV) infection between acute EBV-associated hemophagocytic lymphohistiocytosis and chronic active EBV infection.

PubMed

Kasahara, Y; Yachie, A; Takei, K; Kanegane, C; Okada, K; Ohta, K; Seki, H; Igarashi, N; Maruhashi, K; Katayama, K; Katoh, E; Terao, G; Sakiyama, Y; Koizumi, S

2001-09-15

Unusual Epstein-Barr virus (EBV) infection into T or natural killer cells plays a pivotal role in the pathogenesis of acute EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and chronic active EBV infection (CAEBV). The precise frequency and localization of EBV genome in lymphocyte subpopulations especially within T-cell subpopulations are unclear in these EBV-related disorders. This study analyzed the frequency of EBV-infected cells in circulating lymphocyte subpopulations from 4 patients with acute EBV-HLH and 4 with CAEBV. EBV- encoded small RNA-1 in situ hybridization examination of peripheral blood lymphocytes showed a significantly higher frequency of EBV-infected cells of 1.0% to 13.4% in EBV-HLH and 1.6% to 25.6% in CAEBV, respectively. The patterns of EBV infection in lymphocyte subpopulations were quite different between acute EBV-HLH and CAEBV. EBV infection was predominant in CD8(+) T cells in all EBV-HLH patients, whereas the dominant EBV-infected cell populations were non-CD8(+) lymphocyte subpopulations in CAEBV patients. Phenotypical analysis revealed that EBV-infected cell populations from both EBV-HLH and CAEBV were activated. There was no predominance of any EBV substrain of latent membrane protein-1, EBV-associated nuclear antigen (EBNA)-1, and EBNA-2 genes between the 2 abnormal EBV-associated disorders, and self-limited acute infectious mononucleosis. These results showing differential virus-cell interactions between acute EBV-HLH and CAEBV indicated different pathogenic mechanisms against EBV infection between the 2 EBV-associated diseases, which accounts for the difference in clinical manifestations between the 2 diseases.

Chronic active Epstein-Barr virus infection with marked pericardial effusion successfully treated with allogeneic peripheral blood stem cell transplantation.

PubMed

Matsui, Shinichiro; Takeda, Yusuke; Isshiki, Yusuke; Yamazaki, Atsuko; Nakao, Sanshiro; Takaishi, Koji; Nagao, Yuhei; Hasegawa, Nagisa; Togasaki, Emi; Shimizu, Ryoh; Kawajiri, Chika; Sakai, Shio; Mimura, Naoya; Takeuchi, Masahiro; Ohwada, Chikako; Sakaida, Emiko; Iseki, Tohru; Imadome, Ken-Ichi; Nakaseko, Chiaki

2016-05-01

A 23-year-old woman presented with a persistent fever and shortness of breath. Computed tomography showed marked pericardial effusion, hepatosplenomegaly, and cervical and mediastinal lymph node swelling. Epstein-Barr virus (EBV) antibody titers were abnormally elevated, and the copy number of EBV-DNA was increased in peripheral blood. Based on these observations, she was diagnosed with chronic active EBV infection (CAEBV). The EBV-infected cells in her peripheral blood were CD4(+)T lymphocytes. Fever and pericardial effusion improved following treatment with a combination of prednisolone, etoposide, and cyclosporine; however, peripheral blood EBV-DNA levels remained high. The patient underwent allogeneic peripheral blood stem cell transplantation from an EBV-seronegative, HLA-matched sibling donor, with fludarabine and melphalan conditioning. The post-transplantation course was uneventful, except for mild skin acute graft-versus-host disease (grade 2). EBV-DNA became undetectable in peripheral blood 98 days post transplantation. She has since been in good health without disease recurrence. CAEBV is a potentially fatal disease caused by persistent EBV infection of T lymphocytes or natural killer cells, thus requiring prompt treatment and allogeneic transplantation. Pericardial effusion is rarely observed in CAEBV and can impede its diagnosis. Therefore, we should be aware that patients may present with marked pericardial effusion as an initial manifestation of CAEBV.

Pathogenesis of chronic active Epstein-Barr virus infection: is this an infectious disease, lymphoproliferative disorder, or immunodeficiency?

PubMed

Kimura, Hiroshi

2006-01-01

Chronic active Epstein-Barr virus infection (CAEBV) is characterised by chronic or recurrent infectious mononucleosis-like symptoms, such as fever, hepatosplenomegaly, persistent hepatitis and extensive lymphadenopathy. Patients with CAEBV have high viral loads in their peripheral blood and/or an unusual pattern of EBV-related antibodies. This disease is rare but severe with high morbidity and mortality. Nearly three decades have passed since this disease was first identified, and recent advances in technology have increased our understanding of CAEBV pathophysiology. There is accumulating evidence that the clonal expansion of EBV-infected T or natural killer (NK) cells plays a central role in the pathogenesis of CAEBV. However, it remains unclear whether CAEBV is truly a monoclonal lymphoproliferative disorder. EBV-infected T or NK cells are able to evade the host cellular immune system due to the limited expression of viral proteins of reduced antigenicity. Recent studies suggest that infection of T or NK cells is a common event during primary EBV infection. A defect or single nucleotide polymorphism in host immune-modulating genes may allow for the expansion of virus infected cells giving rise to CAEBV. In this review, I summarise our current understanding of the pathogenesis of CAEBV and propose a model of CAEBV pathogenicity.

Clinical and virologic characteristics of chronic active Epstein-Barr virus infection.

PubMed

Kimura, H; Hoshino, Y; Kanegane, H; Tsuge, I; Okamura, T; Kawa, K; Morishima, T

2001-07-15

Thirty patients with chronic active Epstein-Barr virus (CAEBV) infection were analyzed. The study group included 18 male and 12 female patients, ranging in age from 5 to 31 years with a mean age of 14.2 years. Not all patients had high titers of EBV-specific antibodies, but all patients had high viral loads in their peripheral blood (more than 10(2.5) copies/microg DNA). Fifty percent of the patients displayed chromosomal aberrations, and 79% had monoclonality of EBV. Patients were divided into 2 clinically distinct groups, based on whether the predominantly infected cells in their peripheral blood were T cells or natural killer (NK) cells. Over a 68-month period of observation, 10 patients died from hepatic failure, malignant lymphoma, or other causes. Patients with T-cell CAEBV had a shorter survival time than those with NK-cell type of disease.

Membrane Vesicles Released by Intestinal Epithelial Cells Infected with Rotavirus Inhibit T-Cell Function

PubMed Central

Barreto, Alfonso; Rodríguez, Luz-Stella; Rojas, Olga Lucía; Wolf, Marie; Greenberg, Harry B.; Franco, Manuel A.

2010-01-01

Abstract Rotavirus (RV) predominantly replicates in intestinal epithelial cells (IEC), and “danger signals” released by these cells may modulate viral immunity. We have recently shown that human model IEC (Caco-2 cells) infected with rhesus-RV release a non-inflammatory group of immunomodulators that includes heat shock proteins (HSPs) and TGF-β1. Here we show that both proteins are released in part in association with membrane vesicles (MV) obtained from filtrated Caco-2 supernatants concentrated by ultracentrifugation. These MV express markers of exosomes (CD63 and others), but not of the endoplasmic reticulum (ER) or nuclei. Larger quantities of proteins associated with MV were released by RV-infected cells than by non-infected cells. VP6 co-immunoprecipitated with CD63 present in these MV, and VP6 co-localized with CD63 in RV-infected cells, suggesting that this viral protein is associated with the MV, and that this association occurs intracellularly. CD63 present in MV preparations from stool samples from 36 children with gastroenteritis due or not due to RV were analyzed. VP6 co-immunoprecipitated with CD63 in 3/8 stool samples from RV-infected children, suggesting that these MV are released by RV-infected cells in vivo. Moreover, fractions that contained MV from RV-infected cells induced death and inhibited proliferation of CD4+ T cells to a greater extent than fractions from non-infected cells. These effects were in part due to TGF-β, because they were reversed by treatment of the T cells with the TGF-β-receptor inhibitor ALK5i. MV from RV-infected and non-infected cells were heterogeneous, with morphologies and typical flotation densities described for exosomes (between 1.10 and 1.18 g/mL), and denser vesicles (>1.24 g/mL). Both types of MV from RV-infected cells were more efficient at inhibiting T-cell function than were those from non-infected cells. We propose that RV infection of IEC releases MV that modulate viral immunity. PMID:21142445

Chronic Pseudomonas aeruginosa infection and respiratory muscle impairment in cystic fibrosis.

PubMed

Dassios, Theodore G; Katelari, Anna; Doudounakis, Stavros; Dimitriou, Gabriel

2014-03-01

Chronic infection with Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is associated with increased morbidity. Chronic infection can cause limb and respiratory muscle compromise. Respiratory muscle function can be assessed via maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), and the pressure-time index of the respiratory muscles (PTImus). We studied the effect of chronic P. aeruginosa infection on respiratory muscle function in patients with CF. This cross-sectional study assessed PImax, PEmax, PTImus, FEV1, FVC, maximum expiratory flow during the middle half of the FVC maneuver, body mass index, and upper arm muscle area in 122 subjects with CF, in 4 subgroups matched for age and sex at different stages of P. aeruginosa infection, according to the Leeds criteria. We compared respiratory muscle function in the subgroups according to P. aeruginosa infection state. Median PImax was significantly lower in CF subjects with chronic P. aeruginosa infection (PImax = 62 cm H2O), compared to subjects who were never infected (PImax = 86 cm H2O, P = .02), free of infection (PImax = 74 cm H2O, P = .01), or intermittently infected (PImax = 72 cm H2O, P = .02). Median PTImus was significantly increased in CF subjects with chronic P. aeruginosa infection (PTImus = .142), compared to subjects who were free of infection (PTImus = .102, P = .006). Median upper-arm muscle area was significantly lower in CF subjects with chronic P. aeruginosa infection (upper-arm muscle area = 2,219 mm(2)), compared to subjects who were never infected (2,754 mm(2), P = .03), free of infection (2,678 mm(2), P = .01), or intermittently infected (2,603 mm(2), P = .04). Multivariate logistic regression revealed P. aeruginosa state of infection as a significant determinant of PTImus (P = .03) independently of sex, upper-arm muscle area, and FEV1. CF subjects with chronic P. aeruginosa infection exhibited impaired respiratory muscle function and decreased inspiratory

Onset of Type 1 Diabetes Mellitus During Pegylated-interferon Alfa and Ribavirin Therapy for Chronic Hepatitis C Virus Infection

PubMed Central

Ranganathan, Raghini; Janarthanan, Krishnaveni; Rajasekaran, Senthilkumar

2012-01-01

A 16-year-old female was treated with pegylated-interferon (PEG-IFN) alfa (a)-2b and ribavirin combination therapy for chronic hepatitis C virus (HCV) infection. She attained rapid virological response. She presented with diabetic ketoacidosis after 41 weeks of therapy. Anti-glutamic acid decarboxylase antibodies and islet cell antibodies were negative. Her fasting serum C-peptide level was <0.1 ng/mL, and the treatment course was completed. This case underlines the importance of periodic plasma glucose monitoring in patients during and after PEG-IFN and ribavirin therapy. PMID:25755410

B cell responses to HIV infection

PubMed Central

Moir, Susan; Fauci, Anthony S.

2016-01-01

Summary The induction of neutralizing antibodies directed against the human immunodeficiency virus (HIV) has received considerable attention in recent years, in part driven by renewed interest and opportunities for antibody-based strategies for prevention such as passive transfer of antibodies and the development of preventive vaccines, as well as immune-based therapeutic interventions. Advances in the ability to screen, isolate and characterize HIV-specific antibodies have led to the identification of a new generation of potent broadly neutralizing antibodies (bNAbs). The majority of these antibodies have been isolated from B cells of chronically HIV-infected individuals with detectable viremia. In this review, we provide insight into the phenotypic and functional attributes of human B cells, with a focus on HIV-specific memory B cells and plasmablasts/cells that are responsible for sustaining humoral immune responses against HIV. We discuss the abnormalities in B cells that occur in HIV infection both in the peripheral blood and lymphoid tissues, especially in the setting of persisting viremia. Finally, we consider the opportunities and drawbacks of intensively interrogating antibodies isolated from HIV-infected individuals to guide strategies aimed at developing effective antibody-based vaccine and therapeutic interventions for HIV. PMID:28133792

A lack of Fas/FasL signalling leads to disturbances in the antiviral response during ectromelia virus infection.

PubMed

Bień, K; Sobańska, Z; Sokołowska, J; Bąska, P; Nowak, Z; Winnicka, A; Krzyzowska, M

2016-04-01

Ectromelia virus (ECTV) is an orthopoxvirus (OPV) that causes mousepox, the murine equivalent of human smallpox. Fas receptor-Fas ligand (FasL) signaling is involved in apoptosis of immune cells and virus-specific cytotoxicity. The Fas/FasL pathway also plays an important role in controlling the local inflammatory response during ECTV infection. Here, the immune response to the ECTV Moscow strain was examined in Fas (-) (lpr), FasL (-) (gld) and C57BL6 wild-type mice. During ECTV-MOS infection, Fas- and FasL mice showed increased viral titers, decreased total numbers of NK cells, CD4(+) and CD8(+) T cells followed by decreased percentages of IFN-γ expressing NK cells, CD4(+) and CD8(+) T cells in spleens and lymph nodes. At day 7 of ECTV-MOS infection, Fas- and FasL-deficient mice had the highest regulatory T cell (Treg) counts in spleen and lymph nodes in contrast to wild-type mice. Furthermore, at days 7 and 10 of the infection, we observed significantly higher numbers of PD-L1-expressing dendritic cells in Fas (-) and FasL (-) mice in comparison to wild-type mice. Experiments in co-cultures of CD4(+) T cells and bone-marrow-derived dendritic cells showed that the lack of bilateral Fas-FasL signalling led to expansion of Tregs. In conclusion, our results demonstrate that during ECTV infection, Fas/FasL can regulate development of tolerogenic DCs and Tregs, leading to an ineffective immune response.

Ravuconazole in Preventing Fungal Infections in Patients Undergoing Allogeneic Stem Cell Transplantation

ClinicalTrials.gov

2012-03-07

Breast Cancer; Chronic Myeloproliferative Disorders; Gestational Trophoblastic Tumor; Infection; Leukemia; Lymphoma; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Myelodysplastic/Myeloproliferative Neoplasms; Neuroblastoma; Ovarian Cancer; Testicular Germ Cell Tumor

Common cytological and cytogenetic features of Epstein-Barr virus (EBV)-positive natural killer (NK) cells and cell lines derived from patients with nasal T/NK-cell lymphomas, chronic active EBV infection and hydroa vacciniforme-like eruptions.

PubMed

Zhang, Yu; Nagata, Hiroshi; Ikeuchi, Tatsuro; Mukai, Hiroyuki; Oyoshi, Michiko K; Demachi, Ayako; Morio, Tomohiro; Wakiguchi, Hiroshi; Kimura, Nobuhiro; Shimizu, Norio; Yamamoto, Kohtaro

2003-06-01

In this study, we describe the cytological and cytogenetic features of six Epstein-Barr virus (EBV)-infected natural killer (NK) cell clones. Three cell clones, SNK-1, -3 and -6, were derived from patients with nasal T/NK-cell lymphomas; two cell clones, SNK-5 and -10, were isolated from patients with chronic active EBV infection (CAEBV); and the other cell clone, SNK-11, was from a patient with hydroa vacciniforme (HV)-like eruptions. An analysis of the number of EBV-terminal repeats showed that the SNK cell clones had monoclonal EBV genomes identical to the original EBV-infected cells of the respective patients, and SNK cells had the type II latency of EBV infection, suggesting that not only the cell clones isolated from nasal T/NK-cell lymphomas but also those isolated from CAEBV and HV-like eruptions had been transformed by EBV to a certain degree. Cytogenetic analysis detected deletions in chromosome 6q in five out of the six SNK cell clones, while 6q was not deleted in four control cell lines of T-cell lineage. This suggested that a 6q deletion is a characteristic feature of EBV-positive NK cells, which proliferated in the diseased individuals. The results showed that EBV-positive NK cells in malignant and non-malignant lymphoproliferative diseases shared common cytological and cytogenetic features.

Role of Th17 Cell in Tubercle Bacillus Infection

NASA Astrophysics Data System (ADS)

Zhang, Dandan

2018-01-01

Tuberculosis is mainly a kind of lung disease. Normal immune cell expression can inhibit proliferation of tubercle bacillus in the lungs, but this may also lead to chronic inflammation and pathological lesion. Th17 cell is a newly discovered CD4 + effector T cell subsets, whose differentiation and roles are influenced by various cytokines in the surrounding environment. Th17 cell plays an important role in resisting tubercle bacillus infection, but also it may cause pathological damage through the inflammatory response. Therefore, to balance two kinds of roles of Th17 cells in tubercle bacillus infection can effectively protect the body. This paper intends to do a summary on differentiation, regulation, and biological functions of Th17 cell.

Distinct Macrophage Fates after in vitro Infection with Different Species of Leishmania: Induction of Apoptosis by Leishmania (Leishmania) amazonensis, but Not by Leishmania (Viannia) guyanensis

PubMed Central

DaMata, Jarina Pena; Mendes, Bárbara Pinheiro; Maciel-Lima, Kátia; Menezes, Cristiane Alves Silva; Dutra, Walderez Ornelas; Sousa, Lirlândia Pires; Horta, Maria Fátima

2015-01-01

Leishmania is an intracellular parasite in vertebrate hosts, including man. During infection, amastigotes replicate inside macrophages and are transmitted to healthy cells, leading to amplification of the infection. Although transfer of amastigotes from infected to healthy cells is a crucial step that may shape the outcome of the infection, it is not fully understood. Here we compare L. amazonensis and L. guyanensis infection in C57BL/6 and BALB/c mice and investigate the fate of macrophages when infected with these species of Leishmania in vitro. As previously shown, infection of mice results in distinct outcomes: L. amazonensis causes a chronic infection in both strains of mice (although milder in C57BL/6), whereas L. guyanensis does not cause them disease. In vitro, infection is persistent in L. amazonensis-infected macrophages whereas L. guyanensis growth is controlled by host cells from both strains of mice. We demonstrate that, in vitro, L. amazonensis induces apoptosis of both C57BL/6 and BALB/c macrophages, characterized by PS exposure, DNA cleavage into nucleosomal size fragments, and consequent hypodiploidy. None of these signs were seen in macrophages infected with L. guyanensis, which seem to die through necrosis, as indicated by increased PI-, but not Annexin V-, positive cells. L. amazonensis-induced macrophage apoptosis was associated to activation of caspases-3, -8 and -9 in both strains of mice. Considering these two species of Leishmania and strains of mice, macrophage apoptosis, induced at the initial moments of infection, correlates with chronic infection, regardless of its severity. We present evidence suggestive that macrophages phagocytize L. amazonensis-infected cells, which has not been verified so far. The ingestion of apoptotic infected macrophages by healthy macrophages could be a way of amastigote spreading, leading to the establishment of infection. PMID:26513474

Distinct Macrophage Fates after in vitro Infection with Different Species of Leishmania: Induction of Apoptosis by Leishmania (Leishmania) amazonensis, but Not by Leishmania (Viannia) guyanensis.

PubMed

DaMata, Jarina Pena; Mendes, Bárbara Pinheiro; Maciel-Lima, Kátia; Menezes, Cristiane Alves Silva; Dutra, Walderez Ornelas; Sousa, Lirlândia Pires; Horta, Maria Fátima

2015-01-01

Leishmania is an intracellular parasite in vertebrate hosts, including man. During infection, amastigotes replicate inside macrophages and are transmitted to healthy cells, leading to amplification of the infection. Although transfer of amastigotes from infected to healthy cells is a crucial step that may shape the outcome of the infection, it is not fully understood. Here we compare L. amazonensis and L. guyanensis infection in C57BL/6 and BALB/c mice and investigate the fate of macrophages when infected with these species of Leishmania in vitro. As previously shown, infection of mice results in distinct outcomes: L. amazonensis causes a chronic infection in both strains of mice (although milder in C57BL/6), whereas L. guyanensis does not cause them disease. In vitro, infection is persistent in L. amazonensis-infected macrophages whereas L. guyanensis growth is controlled by host cells from both strains of mice. We demonstrate that, in vitro, L. amazonensis induces apoptosis of both C57BL/6 and BALB/c macrophages, characterized by PS exposure, DNA cleavage into nucleosomal size fragments, and consequent hypodiploidy. None of these signs were seen in macrophages infected with L. guyanensis, which seem to die through necrosis, as indicated by increased PI-, but not Annexin V-, positive cells. L. amazonensis-induced macrophage apoptosis was associated to activation of caspases-3, -8 and -9 in both strains of mice. Considering these two species of Leishmania and strains of mice, macrophage apoptosis, induced at the initial moments of infection, correlates with chronic infection, regardless of its severity. We present evidence suggestive that macrophages phagocytize L. amazonensis-infected cells, which has not been verified so far. The ingestion of apoptotic infected macrophages by healthy macrophages could be a way of amastigote spreading, leading to the establishment of infection.

A Chimeric Humanized Mouse Model by Engrafting the Human Induced Pluripotent Stem Cell-Derived Hepatocyte-Like Cell for the Chronic Hepatitis B Virus Infection

PubMed Central

Yuan, Lunzhi; Liu, Xuan; Zhang, Liang; Li, Xiaoling; Zhang, Yali; Wu, Kun; Chen, Yao; Cao, Jiali; Hou, Wangheng; Zhang, Jun; Zhu, Hua; Yuan, Quan; Tang, Qiyi; Cheng, Tong; Xia, Ningshao

2018-01-01

Humanized mouse model generated by grafting primary human hepatocytes (PHHs) to immunodeficient mouse has contributed invaluably to understanding the pathogenesis of hepatitis B virus (HBV). However, the source of PHHs is limited, which necessitates the search for alternatives. Recently, hepatocyte-like cells (HLCs) generated from human induced pluripotent stem cells (hiPSCs) have been used for in vitro HBV infection. Herein, we developed a robust human liver chimeric animal model to study in vivo HBV infection by engrafting the hiPSC-HLCs to Fah-/-Rag2-/-IL-2Rγc-/- SCID (FRGS) mice. After being optimized by a small molecule, XMU-MP-1, the hiPSC-HLCs engrafted FRGS (hHLC-FRGS) mice displayed approximately 40% liver chimerism at week 6 after engraftment and maintained at this level for at least 14 weeks. Viremia and HBV infection markers include antigens, RNA, DNA, and covalently closed circular DNA were detectable in HBV infected hHLC-FRGS mice. Furthermore, hiPSC-HLCs and hHLC-FRGS mice were successfully used to evaluate different antivirals. Therefore, we established a humanized mouse model for not only investigating HBV pathogenesis but also testing the effects of the anti-HBV drugs. Highlights:    (1) The implanted hiPSC-HLCs established a long-term chimerism in FRGS mice liver.    (2) hHLC-FRGS mice are adequate to support chronic HBV infection with a full viral life cycle.    (3) hiPSC-HLCs and hHLC-FRGS mice are useful tools for evaluation of antivirals against HBV infection in vitro and in vivo. Research in Context  To overcome the disadvantages of using primary human hepatocytes, we induced human pluripotent stem cells to hepatocyte-like cells (hiPSC-HLCs) that developed the capability to express important liver functional markers and critical host factors for HBV infection. The hiPSC-HLCs were permissive for the HBV infection and supported a full HBV replication. The hiPSC-HLCs were then engrafted to immunodeficient mouse to establish a

Cardiomyocyte dysfunction during the chronic phase of Chagas disease.

PubMed

Roman-Campos, Danilo; Sales-Júnior, Policarpo; Duarte, Hugo Leonardo; Gomes, Eneas Ricardo; Guatimosim, Silvia; Ropert, Catherine; Gazzinelli, Ricardo Tostes; Cruz, Jader Santos

2013-04-01

Chagas disease, which is caused by the parasite Trypanosoma cruzi, is an important cause of heart failure. We investigated modifications in the cellular electrophysiological and calcium-handling characteristics of an infected mouse heart during the chronic phase of the disease. The patch-clamp technique was used to record action potentials (APs) and L-type Ca2+ and transient outward K+ currents. [Ca2+]i changes were determined using confocal microscopy. Infected ventricular cells showed prolonged APs, reduced transient outward K+ and L-type Ca2+ currents and reduced Ca2+ release from the sarcoplasmic reticulum. Thus, the chronic phase of Chagas disease is characterised by cardiomyocyte dysfunction, which could lead to heart failure.

Cardiomyocyte dysfunction during the chronic phase of Chagas disease

PubMed Central

Roman-Campos, Danilo; Sales-Júnior, Policarpo; Duarte, Hugo Leonardo; Gomes, Eneas Ricardo; Guatimosim, Silvia; Ropert, Catherine; Gazzinelli, Ricardo Tostes; Cruz, Jader Santos

2013-01-01

Chagas disease, which is caused by the parasite Trypanosoma cruzi, is an important cause of heart failure. We investigated modifications in the cellular electrophysiological and calcium-handling characteristics of an infected mouse heart during the chronic phase of the disease. The patch-clamp technique was used to record action potentials (APs) and L-type Ca2+ and transient outward K+ currents. [Ca2+]i changes were determined using confocal microscopy. Infected ventricular cells showed prolonged APs, reduced transient outward K+ and L-type Ca2+ currents and reduced Ca2+ release from the sarcoplasmic reticulum. Thus, the chronic phase of Chagas disease is characterised by cardiomyocyte dysfunction, which could lead to heart failure. PMID:23579807

Clonal expansion of Epstein-Barr virus (EBV)-infected γδ T cells in patients with chronic active EBV disease and hydroa vacciniforme-like eruptions.

PubMed

Wada, Taizo; Toga, Akiko; Sakakibara, Yasuhisa; Toma, Tomoko; Hasegawa, Minoru; Takehara, Kazuhiko; Shigemura, Tomonari; Agematsu, Kazunaga; Yachie, Akihiro

2012-10-01

Chronic active Epstein-Barr virus (EBV) disease (CAEBV) is a systemic EBV-positive lymphoproliferative disorder characterized by fever, lymphadenopathy, and splenomegaly. Patients with CAEBV may present with cutaneous symptoms, including hypersensitivity to mosquito bites and hydroa vacciniforme (HV)-like eruptions. HV is a rare photodermatosis characterized by vesicles and crust formation after exposure to sunlight, with onset in childhood, and is associated with latent EBV infection. While γδ T cells have recently been demonstrated to be the major EBV-infected cell population in HV, the immunophenotypic features of EBV-infected γδ T cells in CAEBV with HV-like eruptions or HV remain largely undetermined. We describe three patients with CAEBV whose γδ T cells were found to be the major cellular target of EBV. HV-like eruptions were observed in two of these patients. A clonally expanded subpopulation of γδ T cells that were highly activated and T cell receptor Vγ9- and Vδ2-positive cells was demonstrated in all patients. We also show that the clonally expanded γδ T cells infiltrated into the HV-like eruptions in one patient from whom skin biopsy specimens were available. These results suggest the pathogenic roles of clonally expanded γδ T cells infected by EBV in patients with CAEBV and HV-like eruptions.

Direct evidence for a chronic CD8+-T-cell-mediated immune reaction to tax within the muscle of a human T-cell leukemia/lymphoma virus type 1-infected patient with sporadic inclusion body myositis.

PubMed

Ozden, Simona; Cochet, Madeleine; Mikol, Jacqueline; Teixeira, Antonio; Gessain, Antoine; Pique, Claudine

2004-10-01

Human T-cell leukemia/lymphoma virus type 1 (HTLV-1) infection can lead to the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), concomitantly with or without other inflammatory disorders such as myositis. These pathologies are considered immune-mediated diseases, and it is assumed that migration within tissues of both HTLV-1-infected CD4(+) T cells and anti-HTLV-1 cytotoxic T cells represents a pivotal event. However, although HTLV-1-infected T cells were found in inflamed lesions, the antigenic specificity of coinfiltrated CD8(+) T cells remains to be determined. In this study, we performed both ex vivo and in situ analyses using muscle biopsies obtained from an HTLV-1-infected patient with HAM/TSP and sporadic inclusion body myositis. We found that both HTLV-1-infected CD4(+) T cells and CD8(+) T cells directed to the dominant Tax antigen can be amplified from muscle cell cultures. Moreover, we were able to detect in two successive muscle biopsies both tax mRNA-positive mononuclear cells and T cells recognized by the Tax11-19/HLA-A*02 tetramer and positive for perforin. These findings provide the first direct demonstration that anti-Tax cytotoxic T cells are chronically recruited within inflamed tissues of an HTLV-1 infected patient, which validates the cytotoxic immune reaction model for the pathogenesis of HTLV-1-associated inflammatory disease.

Homeostatic Proliferation and IL-7R Alpha Expression Do Not Correlate with Enhanced T Cell Proliferation and Protection in Chronic Mouse Malaria

PubMed Central

Stephens, Robin; Seddon, Benedict; Langhorne, Jean

2011-01-01

While chronic infection has been shown to enhance protection from disease caused by several pathogens, the mechanisms are not known. The gamma-c family of cytokines IL-7, IL-2, and IL-15 are implicated in homeostatic proliferation, which is thought to maintain T cell memory. However in chronic infection, prolonged antigen exposure itself may contribute to lymphocyte survival. We have previously observed that chronic malaria infection enhances protection to re-infection, as well as enhancing B cell responses. Here, we show that chronic Plasmodium chabaudi malaria infection in mice enhances the expansion of CD4+ T cells in a second infection, and that this correlates with increased expression of the IL-2/15 Receptor beta (CD122) on memory T cells, as well as increasing IL-2 producers on re-infection. IL-2 has been recently linked to improved secondary proliferation, while the role of IL-7 in maintenance of CD4+ memory cells has been demonstrated in homeostatic proliferation, but its role in protective memory populations in infectious disease protective has not been fully investigated. Increased IL-7Rα (CD127) expression correlated, as previously reported with increased turnover of CD4 memory cells, however, this was not linked to protection or enhanced response to rechallenge, These data support the idea that antigen or IL-2 production resulting from chronic stimulation may play a role in an enhanced secondary T cell response. PMID:22039531

N1L is an ectromelia virus virulence factor and essential for in vivo spread upon respiratory infection.

PubMed

Gratz, Meike S; Suezer, Yasemin; Kremer, Melanie; Volz, Asisa; Majzoub, Monir; Hanschmann, Kay-Martin; Kalinke, Ulrich; Schwantes, Astrid; Sutter, Gerd

2011-04-01

The emergence of zoonotic orthopoxvirus infections and the threat of possible intentional release of pathogenic orthopoxviruses have stimulated renewed interest in understanding orthopoxvirus infections and the resulting diseases. Ectromelia virus (ECTV), the causative agent of mousepox, offers an excellent model system to study an orthopoxvirus infection in its natural host. Here, we investigated the role of the vaccinia virus ortholog N1L in ECTV infection. Respiratory infection of mice with an N1L deletion mutant virus (ECTVΔN1L) demonstrated profound attenuation of the mutant virus, confirming N1 as an orthopoxvirus virulence factor. Upon analysis of virus dissemination in vivo, we observed a striking deficiency of ECTVΔN1L spreading from the lungs to the livers or spleens of infected mice. Investigating the immunological mechanism controlling ECTVΔN1L infection, we found the attenuated phenotype to be unaltered in mice deficient in Toll-like receptor (TLR) or RIG-I-like RNA helicase (RLH) signaling as well as in those missing the type I interferon receptor or lacking B cells. However, in RAG-1(-/-) mice lacking mature B and T cells, ECTVΔN1L regained virulence, as shown by increasing morbidity and virus spread to the liver and spleen. Moreover, T cell depletion experiments revealed that ECTVΔN1L attenuation was reversed only by removing both CD4(+) and CD8(+) T cells, so the presence of either cell subset was still sufficient to control the infection. Thus, the orthopoxvirus virulence factor N1 may allow efficient ECTV infection in mice by interfering with host T cell function.

Regulatory T Cells in Autoimmune and Viral Chronic Hepatitis

PubMed Central

Lapierre, Pascal; Lamarre, Alain

2015-01-01

In both autoimmune liver disease and chronic viral hepatitis, the injury results from an immune-mediated cytotoxic T cell response to liver cells. As such, it is not surprising that CD4+ regulatory T cells, a key regulatory population of T cells able to curb immune responses, could be involved in both autoimmune hepatitis and chronic viral hepatitis. The liver can induce the conversion of naïve CD4+ T cells to CD4+ regulatory T cells and induce tolerance to locally expressed antigens. This tolerance mechanism is carefully regulated in physiological conditions but any imbalance could be pathological. An overly tolerant immune response can lead to chronic infections while an overreactive and unbridled immune response can lead to autoimmune hepatitis. With the recent advent of monoclonal antibodies able to target regulatory T cells (daclizumab) and improve immune responses and several ongoing clinical trials analysing the impact of regulatory T cell infusion on autoimmune liver disease or liver transplant tolerance, modulation of immunological tolerance through CD4+ regulatory T cells could be a key element of future immunotherapies for several liver diseases allowing restoring the balance between proper immune responses and tolerance.   PMID:26106627

Acute and chronic T cell dynamics in the livers of simian immunodeficiency virus-infected macaques.

PubMed

Ahsan, Muhammad H; Gill, Amy F; Lackner, Andrew A; Veazey, Ronald S

2012-05-01

The mucosal immune system, particularly the gastrointestinal tract, is critically involved in the pathogenesis of human immunodeficiency virus (HIV) infection. Since the liver drains most of the substances coming from the intestinal tract, it may also play a role in the pathogenesis of HIV infection. Here we examined the percentages and absolute numbers of T cell subsets in the liver in normal and simian immunodeficiency virus (SIV)-infected macaques. Most of the T cells in the liver were CD8(+) memory cells, and most of these had an effector memory (CD95(+) CD28(-)) phenotype. CD4(+) T cells constituted approximately 20% of the liver T cell population, but the vast majority of these were also memory (CD95(+)) CCR5(+) cells, suggesting they were potential targets for viral infection. After SIV infection, CD4(+) T cells were markedly reduced, and increased proliferation and absolute numbers of CD8(+) T cells were detected in the liver. These data suggest that the liver is a major source of antigenic stimulation for promoting CD8(+) T cells and possibly a source for early CD4(+) T cell infection and destruction.

Acute and Chronic T Cell Dynamics in the Livers of Simian Immunodeficiency Virus-Infected Macaques

PubMed Central

Ahsan, Muhammad H.; Gill, Amy F.; Lackner, Andrew A.

2012-01-01

The mucosal immune system, particularly the gastrointestinal tract, is critically involved in the pathogenesis of human immunodeficiency virus (HIV) infection. Since the liver drains most of the substances coming from the intestinal tract, it may also play a role in the pathogenesis of HIV infection. Here we examined the percentages and absolute numbers of T cell subsets in the liver in normal and simian immunodeficiency virus (SIV)-infected macaques. Most of the T cells in the liver were CD8+ memory cells, and most of these had an effector memory (CD95+ CD28−) phenotype. CD4+ T cells constituted approximately 20% of the liver T cell population, but the vast majority of these were also memory (CD95+) CCR5+ cells, suggesting they were potential targets for viral infection. After SIV infection, CD4+ T cells were markedly reduced, and increased proliferation and absolute numbers of CD8+ T cells were detected in the liver. These data suggest that the liver is a major source of antigenic stimulation for promoting CD8+ T cells and possibly a source for early CD4+ T cell infection and destruction. PMID:22379078

Chronic lymphocytic leukemia skin infiltration mimicking an ICD pocket infection: a case report.

PubMed

Snorek, M; Bulava, A; Vonke, I

2017-03-24

We are presenting a case report on an unreported and unusual cutaneous manifestation of chronic lymphocytic leukemia in a patient with an implantable cardioverter-defibrillator (ICD). A 65-year-old man with a history of chronic lymphocytic leukemia (CLL), previously treated with chlorambucil, was referred in October 2013 for extraction of a single chamber ICD due to a suspected device-related infection in the pulse generator area (left-hand side of Fig. 1). The ICD system (Current VR, St. Jude Medical, USA) had been implanted in November 2009. The patient complained of painless erythema with pruritus in the pocket area. Inflammatory blood parameters were C-reactive protein 17.3 mg/L and leucocytes 29.0 × 10 9 /L. Due to the atypical appearance of the pocket area we did not extract the device. Instead, we created an exploratory excision in the skin induration, which had been present for approximately 6 weeks, and conducted a microbiological and histological examination. All cultivation examinations were negative. However, we did histologically show skin infiltration by CD-5 positive low-grade B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (B-CLL/SLL). Re-initiation of chemotherapy was not necessary and the skin induration completely disappeared within 2 months (right-hand side of Fig. 1). Complete removal of an ICD system carries considerable risk. In patients with a history of hematological disease, it is crucial to exclude cutaneous manifestations of the disease prior to device removal.

Anticancer compound ABT-263 accelerates apoptosis in virus-infected cells and imbalances cytokine production and lowers survival rates of infected mice.

PubMed

Kakkola, L; Denisova, O V; Tynell, J; Viiliäinen, J; Ysenbaert, T; Matos, R C; Nagaraj, A; Ohman, T; Kuivanen, S; Paavilainen, H; Feng, L; Yadav, B; Julkunen, I; Vapalahti, O; Hukkanen, V; Stenman, J; Aittokallio, T; Verschuren, E W; Ojala, P M; Nyman, T; Saelens, X; Dzeyk, K; Kainov, D E

2013-07-25

ABT-263 and its structural analogues ABT-199 and ABT-737 inhibit B-cell lymphoma 2 (Bcl-2), BCL2L1 long isoform (Bcl-xL) and BCL2L2 (Bcl-w) proteins and promote cancer cell death. Here, we show that at non-cytotoxic concentrations, these small molecules accelerate the deaths of non-cancerous cells infected with influenza A virus (IAV) or other viruses. In particular, we demonstrate that ABT-263 altered Bcl-xL interactions with Bcl-2 antagonist of cell death (Bad), Bcl-2-associated X protein (Bax), uveal autoantigen with coiled-coil domains and ankyrin repeats protein (UACA). ABT-263 thereby activated the caspase-9-mediated mitochondria-initiated apoptosis pathway, which, together with the IAV-initiated caspase-8-mediated apoptosis pathway, triggered the deaths of IAV-infected cells. Our results also indicate that Bcl-xL, Bcl-2 and Bcl-w interact with pattern recognition receptors (PRRs) that sense virus constituents to regulate cellular apoptosis. Importantly, premature killing of IAV-infected cells by ABT-263 attenuated the production of key pro-inflammatory and antiviral cytokines. The imbalance in cytokine production was also observed in ABT-263-treated IAV-infected mice, which resulted in an inability of the immune system to clear the virus and eventually lowered the survival rates of infected animals. Thus, the results suggest that the chemical inhibition of Bcl-xL, Bcl-2 and Bcl-w could potentially be hazardous for cancer patients with viral infections.

Chronic hepatitis C virus infection triggers spontaneous differential expression of biosignatures associated with T cell exhaustion and apoptosis signaling in peripheral blood mononucleocytes.

PubMed

Barathan, Muttiah; Gopal, Kaliappan; Mohamed, Rosmawati; Ellegård, Rada; Saeidi, Alireza; Vadivelu, Jamuna; Ansari, Abdul W; Rothan, Hussin A; Ravishankar Ram, M; Zandi, Keivan; Chang, Li Y; Vignesh, Ramachandran; Che, Karlhans F; Kamarulzaman, Adeeba; Velu, Vijayakumar; Larsson, Marie; Kamarul, Tunku; Shankar, Esaki M

2015-04-01

Persistent hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion to potentially assist viral persistence in the host, eventually leading to hepatocellular carcinoma. The role of HCV on the spontaneous expression of markers suggestive of immune exhaustion and spontaneous apoptosis in immune cells of chronic HCV (CHC) disease largely remain elusive. We investigated the peripheral blood mononuclear cells of CHC patients to determine the spontaneous recruitment of cellular reactive oxygen species (cROS), immunoregulatory and exhaustion markers relative to healthy controls. Using a commercial QuantiGenePlex(®) 2.0 assay, we determined the spontaneous expression profile of 80 different pro- and anti-apoptotic genes in persistent HCV disease. Onset of spontaneous apoptosis significantly correlated with the up-regulation of cROS, indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2/prostaglandin H synthase (COX-2/PGHS), Foxp3, Dtx1, Blimp1, Lag3 and Cd160. Besides, spontaneous differential surface protein expression suggestive of T cell inhibition viz., TRAIL, TIM-3, PD-1 and BTLA on CD4+ and CD8+ T cells, and CTLA-4 on CD4+ T cells was also evident. Increased up-regulation of Tnf, Tp73, Casp14, Tnfrsf11b, Bik and Birc8 was observed, whereas FasLG, Fas, Ripk2, Casp3, Dapk1, Tnfrsf21, and Cflar were moderately up-regulated in HCV-infected subjects. Our observation suggests the spontaneous onset of apoptosis signaling and T cell exhaustion in chronic HCV disease.

PD-1 is a marker for abnormal distribution of naïve/memory T cell subsets in HIV-1 infection

PubMed Central

Breton, Gaëlle; Chomont, Nicolas; Takata, Hiroshi; Fromentin, Rémi; Ahlers, Jeffrey; Filali-Mouhim, Abdelali; Riou, Catherine; Boulassel, Mohamed-Rachid; Routy, Jean-Pierre; Yassine-Diab, Bader; Sékaly, Rafick-Pierre

2013-01-01

Chronic activation of T cells is a hallmark of HIV-1 infection and plays an important role in disease progression. We previously showed that the engagement of the inhibitory receptor PD-1 on HIV-1 specific CD4+ and CD8+ T cells leads to their functional exhaustion in vitro. However, little is known about the impact of PD-1 expression on the turnover and maturation status of T cells during the course of the disease. Here, we show that PD-1 is up regulated on all T cell subsets including naïve, central memory and transitional memory T cells in HIV-1 infected subjects. PD-1 is expressed at similar levels on most CD4+ T cells during the acute and the chronic phase of disease and identifies cells that have recently entered the cell cycle. In contrast, PD-1 expression dramatically increased in CD8+ T cells during the transition from acute to chronic infection and this was associated with reduced levels of cell proliferation. The failure to down regulate expression of PD-1 in most T cells during chronic HIV-1 infection was associated to persistent alterations in the distribution of T cell subsets and was associated with impaired responses to IL-7. Our findings identify PD-1 as a marker for aberrant distribution of T cell subsets in HIV-1 infection. PMID:23918986

Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

NASA Astrophysics Data System (ADS)

Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.

2014-01-01

The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.

Engaging the CD40-CD40L pathway augments T-helper cell responses and improves control of Mycobacterium tuberculosis infection

PubMed Central

Bizzell, Erica; Madan-Lala, Ranjna

2017-01-01

Mycobacterium tuberculosis (Mtb) impairs dendritic cell (DC) functions and induces suboptimal antigen-specific CD4 T cell immune responses that are poorly protective. Mucosal T-helper cells producing IFN-γ (Th1) and IL-17 (Th17) are important for protecting against tuberculosis (TB), but the mechanisms by which DCs generate antigen-specific T-helper responses during Mtb infection are not well defined. We previously reported that Mtb impairs CD40 expression on DCs and restricts Th1 and Th17 responses. We now demonstrate that CD40-dependent costimulation is required to generate IL-17 responses to Mtb. CD40-deficient DCs were unable to induce antigen-specific IL-17 responses after Mtb infection despite the production of Th17-polarizing innate cytokines. Disrupting the interaction between CD40 on DCs and its ligand CD40L on antigen-specific CD4 T cells, genetically or via antibody blockade, significantly reduced antigen-specific IL-17 responses. Importantly, engaging CD40 on DCs with a multimeric CD40 agonist (CD40LT) enhanced antigen-specific IL-17 generation in ex vivo DC-T cell co-culture assays. Further, intratracheal instillation of Mtb-infected DCs treated with CD40LT significantly augmented antigen-specific Th17 responses in vivo in the lungs and lung-draining lymph nodes of mice. Finally, we show that boosting CD40-CD40L interactions promoted balanced Th1/Th17 responses in a setting of mucosal DC transfer, and conferred enhanced control of lung bacterial burdens following aerosol challenge with Mtb. Our results demonstrate that CD40 costimulation by DCs plays an important role in generating antigen-specific Th17 cells and targeting the CD40-CD40L pathway represents a novel strategy to improve adaptive immunity to TB. PMID:28767735

Atlantic salmon reovirus infection causes a CD8 T cell myocarditis in Atlantic salmon (Salmo salar L.).

PubMed

Mikalsen, Aase B; Haugland, Oyvind; Rode, Marit; Solbakk, Inge Tom; Evensen, Oystein

2012-01-01

Heart and skeletal inflammation (HSMI) of farmed Atlantic salmon (Salmo salar L.) is a disease characterized by a chronic myocarditis involving the epicardium and the compact and spongious part of the heart ventricle. Chronic myositis of the red skeletal muscle is also a typical finding of HSMI. Piscine reovirus (PRV) has been detected by real-time PCR from farmed and wild salmon with and without typical changes of HSMI and thus the causal relationship between presence of virus and the disease has not been fully determined. In this study we show that the Atlantic salmon reovirus (ASRV), identical to PRV, can be passaged in GF-1 cells and experimental challenge of naïve Atlantic salmon with cell culture passaged reovirus results in cardiac and skeletal muscle pathology typical of HSMI with onset of pathology from 6 weeks, peaking by 9 weeks post challenge. ASRV replicates in heart tissue and the peak level of virus replication coincides with peak of heart lesions. We further demonstrate mRNA transcript assessment and in situ characterization that challenged fish develop a CD8+ T cell myocarditis.

Beneficial Effects of cART Initiated during Primary and Chronic HIV-1 Infection on Immunoglobulin-Expression of Memory B-Cell Subsets.

PubMed

Pogliaghi, Manuela; Ripa, Marco; Pensieroso, Simone; Tolazzi, Monica; Chiappetta, Stefania; Nozza, Silvia; Lazzarin, Adriano; Tambussi, Giuseppe; Scarlatti, Gabriella

2015-01-01

During HIV-1 infection the B-cell compartment undergoes profound changes towards terminal differentiation, which are only partially restored by antiretroviral therapy (cART). To investigate the impact of infection as early as during primary HIV-1 infection (PHI) we assessed distribution of B-cell subsets in 19 PHI and 25 chronic HIV-1-infected (CHI) individuals before and during 48 weeks of cART as compared to healthy controls (n = 23). We also analysed Immunoglobulin-expression of memory B-cell subsets to identify alterations in Immunoglobulin-maturation. Determination of B-cell subsets at baseline showed that total and Naive B-cells were decreased whereas Activated Memory (AM), Tissue-like Memory (TLM) B-cells and Plasma cells were increased in both PHI and CHI patients. After 4 weeks of cART total B-cells increased, while AM, TLM B-cells and Plasma cells decreased, although without reaching normal levels in either group of individuals. This trend was maintained until week 48, though only total B-cells normalized in both PHI and CHI. Resting Memory (RM) B-cells were preserved since baseline. This subset remained stable in CHI, while was expanded by an early initiation of cART during PHI. Untreated CHI patients showed IgM-overexpression at the expenses of switched (IgM-IgD-) phenotypes of the memory subsets. Interestingly, in PHI patients a significant alteration of Immunoglobulin-expression was evident at BL in TLM cells, and after 4 weeks, despite treatment, in AM and RM subsets. After 48 weeks of therapy, Immunoglobulin-expression of AM and RM almost normalized, but remained perturbed in TLM cells in both groups. In conclusion, aberrant activated and exhausted B-cell phenotypes rose already during PHI, while most of the alterations in Ig-expression seen in CHI appeared later, despite 4 weeks of effective cART. After 48 weeks of cART B-cell subsets distribution improved although without full normalization, while Immunoglobulin-expression normalized among AM and

Presence of natural killer-cell clones with variable proliferative capacity in chronic active Epstein-Barr virus infection.

PubMed

Nagata, H; Numata, T; Konno, A; Mikata, I; Kurasawa, K; Hara, S; Nishimura, M; Yamamoto, K; Shimizu, N

2001-10-01

Chronic active Epstein-Barr virus infection (CAEBV) is a syndrome that takes diverse clinical courses and is often associated with lymphoproliferative disorders of T/natural killer (NK)-cell lineage. We describe a patient with CAEBV associated with persistent pharyngeal ulcer, and with subsequent nasal T/NK-cell lymphoma in her neck lymph nodes and nasopharynx. Immunophenotyping of lymphoid cells showed that the lineage of Epstein-Barr virus (EBV)-positive cells in the patient was of NK-cell origin. By means of high-dose recombinant interleukin-2, we established an EBV-positive cell line of NK-cell lineage from her peripheral blood. Southern blot analysis for the number of terminal repeat sequences of EBV detected three NK-cell clones in the patient's lymph node. One of these clones was identical to the established cell line but was not observed in the pharyngeal ulcer, while the other two clones were present in the pharyngeal ulcer. These results suggest that the patient had expansion of the three NK-cell clones, one of which had proliferative capacity in vitro and was involved in the formation of the lymphoma. Moreover, the results suggest that the proliferative capacity of EBV-positive cells can be variable even in a single patient, and this variability may explain the clinical diversity in CAEBV.

[Can the treatment with L-carnitine improve the inflammation in chronic hemodialysis patients?].

PubMed

Grazi, G; Meriggioli, M; Donati, G

2004-01-01

Inflammation in patients on chronic hemodialysis (HD) is related to malnutrition and atherosclerosis; anemia is also often present in these patients. It has been demonstrated that l-carnitina treatment, in addition to reducing the need for erythropoietin (EPO), improves nutritional parameters and cardiac performance. To evaluate the effect of l-carnitine on the inflammatory pathology in patients on chronic HD, we studied 11 patients with no sure signs of malnutrition, flogistic and infective pathologies and with C-reactive protein (CRP) <2 mg/dL. We evaluated at baseline, after 6 and 12 months CRP, serum albumin, hemoglobin (Hb),nPCR and EPO weekly requirement. We observed a reduction in CRP (from 0.88 +/- 0.65 to 0.42 +/- 0.17 mg/dL after 6 months and to 0.50 + 0.36 mg/dL after 12 months), an increase in serum albumin (from 10.9 +/- 1.23 to 2.08 +/- 1.88 and to 11.8 +/- 1.15 g/dL) and an increase in nPCR (from 0.96 +/- 0.09 to 1.15 +/- 0.2 and to 1.16 +/- 0.18 g/kg/die); EPO weekly requirement decreased (from 7363 +/- 2941 to 5909 +/- 3207 units after 6 months and to 5363 +/- 3139 units after 12 months). These results seem to underline a positive effect of l-carnitine on the inflammatory pathology of patients on chronic hemodialytic treatment.

B-cell responses to HIV infection.

PubMed

Moir, Susan; Fauci, Anthony S

2017-01-01

The induction of neutralizing antibodies directed against the human immunodeficiency virus (HIV) has received considerable attention in recent years, in part driven by renewed interest and opportunities for antibody-based strategies for prevention such as passive transfer of antibodies and the development of preventive vaccines, as well as immune-based therapeutic interventions. Advances in the ability to screen, isolate, and characterize HIV-specific antibodies have led to the identification of a new generation of potent broadly neutralizing antibodies (bNAbs). The majority of these antibodies have been isolated from B cells of chronically HIV-infected individuals with detectable viremia. In this review, we provide insight into the phenotypic and functional attributes of human B cells, with a focus on HIV-specific memory B cells and plasmablasts/cells that are responsible for sustaining humoral immune responses against HIV. We discuss the abnormalities in B cells that occur in HIV infection both in the peripheral blood and lymphoid tissues, especially in the setting of persisting viremia. Finally, we consider the opportunities and drawbacks of intensively interrogating antibodies isolated from HIV-infected individuals to guide strategies aimed at developing effective antibody-based vaccine and therapeutic interventions for HIV. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

The art of persistence—the secrets to Burkholderia chronic infections

PubMed Central

Lewis, Eric R. G.; Torres, Alfredo G.

2016-01-01

The Gram-negative proteobacteria genus Burkholderia encompasses multiple bacterial species that are pathogenic to humans and other vertebrates. Two pathogenic species of interest within this genus are Burkholderia pseudomallei (Bpm) and the B. cepacia complex (Bcc); the former is the causative agent of melioidosis in humans and other mammals, and the latter is associated with pneumonia in immunocompromised patients. One understudied and shared characteristic of these two pathogenic groups is their ability to persist and establish chronic infection within the host. In this review, we will explore the depth of knowledge about chronic infections caused by persistent Bpm and Bcc. We examine the host risk factors and immune responses associated with more severe chronic infections. We also discuss host adaptation and phenotypes associated with persistent Burkholderia species. Lastly, we survey how other intracellular bacteria associated with chronic infections are combatted and explore possible future applications to target Burkholderia. Our goal is to highlight understudied areas that should be addressed for a more thorough understanding of chronic Burkholderia infections and how to combat them. PMID:27440810

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.

PD-L2 Elbows out PD-L1 to Rescue T Cell Immunity to Malaria.

PubMed

Crompton, Peter D; Pierce, Susan K

2016-08-16

How early interactions between innate and adaptive immune cells influence outcomes of acute infections is incompletely understood. In this issue of Immunity, Karunarathne et al. (2016) show that dendritic cells help CD4(+) T helper 1 cell immunity against malaria through PD-L2's competition with PD-L1. Published by Elsevier Inc.

Successful control of Epstein-Barr virus (EBV)-infected cells by allogeneic nonmyeloablative stem cell transplantation in a patient with the lethal form of chronic active EBV infection.

PubMed

Uehara, Taeko; Nakaseko, Chiaki; Hara, Satoru; Harima, Akane; Ejiri, Megumi; Yokota, Akira; Saito, Yasushi; Nishimura, Miki

2004-08-01

Chronic active Epstein-Barr virus infection (CAEBV) is a heterogeneous EBV-related disorder, ranging from mild/moderate forms to rapidly lethal disorders. The lethal form of CAEBV is characterized by multiple organ failure, hemophagocytic syndrome, and development of lymphomas. Allogeneic stem cell transplantation is considered as the only potentially curative treatment for the lethal form of CAEBV, but it is not always desirable because of the high incidence of regimen-related toxicities. A 17-year-old female with CAEBV, who was refractory to conventional therapies and considered to be unable to receive a myeloablative regimen because of multiple organ dysfunction, underwent allogeneic nonmyeloablative stem cell transplantation (allo-NST) before developing a hematological malignancy. She has been well without any signs of CAEBV for 27 months after allo-NST, and we confirmed that specific cytotoxic T lymphocyte activity against EBV was reconstituted. This outcome suggests that allo-NST can control CAEBV by reconstituting the host immunity against EBV. Copyright 2004 Wiley-Liss, Inc.

Involvement of Lysosome Membrane Permeabilization and Reactive Oxygen Species Production in the Necrosis Induced by Chlamydia muridarum Infection in L929 Cells.

PubMed

Chen, Lixiang; Wang, Cong; Li, Shun; Yu, Xin; Liu, Xue; Ren, Rongrong; Liu, Wenwen; Zhou, Xiaojing; Zhang, Xiaonan; Zhou, Xiaohui

2016-04-28

Chlamydiae, obligate intracellular bacteria, are associated with a variety of human diseases. The chlamydial life cycle undergoes a biphasic development: replicative reticulate bodies (RBs) phase and infectious elementary bodies (EBs) phase. At the end of the chlamydial intracellular life cycle, EBs have to be released to the surrounded cells. Therefore, the interactions between Chlamydiae and cell death pathways could greatly influence the outcomes of Chlamydia infection. However, the underlying molecular mechanisms remain elusive. Here, we investigated host cell death after Chlamydia infection in vitro, in L929 cells, and showed that Chlamydia infection induces cell necrosis, as detected by the propidium iodide (PI)-Annexin V double-staining flow-cytometric assay and Lactate dehydrogenase (LDH) release assay. The production of reactive oxygen species (ROS), an important factor in induction of necrosis, was increased after Chlamydia infection, and inhibition of ROS with specific pharmacological inhibitors, diphenylene iodonium (DPI) or butylated hydroxyanisole (BHA), led to significant suppression of necrosis. Interestingly, live-cell imaging revealed that Chlamydia infection induced lysosome membrane permeabilization (LMP). When an inhibitor upstream of LMP, CA-074-Me, was added to cells, the production of ROS was reduced with concomitant inhibition of necrosis. Taken together, our results indicate that Chlamydia infection elicits the production of ROS, which is dependent on LMP at least partially, followed by induction of host-cell necrosis. To our best knowledge, this is the first live-cell-imaging observation of LMP post Chlamydia infection and report on the link of LMP to ROS to necrosis during Chlamydia infection.

Role of Bruton's tyrosine kinase inhibitors in HIV-1-infected cells.

PubMed

Guendel, Irene; Iordanskiy, Sergey; Sampey, Gavin C; Van Duyne, Rachel; Calvert, Valerie; Petricoin, Emanuel; Saifuddin, Mohammed; Kehn-Hall, Kylene; Kashanchi, Fatah

2015-06-01

Many cellular cofactors have been documented to be critical for various stages of viral replication. Using high-throughput proteomic assays, we have previously identified Bruton's tyrosine kinase (BTK) as a host protein that was uniquely upregulated in the plasma membrane of human immunodeficiency virus (HIV-1)-infected T cells. Here, we have further characterized the BTK expression in HIV-1 infection and show that this cellular factor is specifically expressed in infected myeloid cells. Significant upregulation of the phosphorylated form of BTK was observed in infected cells. Using size exclusion chromatography, we found BTK to be virtually absent in the uninfected U937 cells; however, new BTK protein complexes were identified and distributed in both high molecular weight (∼600 kDa) and a small molecular weight complex (∼60-120 kDa) in the infected U1 cells. BTK levels were highest in cells either chronically expressing virus or induced/infected myeloid cells and that BTK translocated to the membrane following induction of the infected cells. BTK knockdown in HIV-1-infected cells using small interfering RNA (siRNA) resulted in selective death of infected, but not uninfected, cells. Using BTK-specific antibody and small-molecule inhibitors including LFM-A13 and a FDA-approved compound, ibrutinib (PCI-32765), we have found that HIV-1-infected cells are sensitive to apoptotic cell death and result in a decrease in virus production. Overall, our data suggests that HIV-1-infected cells are sensitive to treatments targeting BTK expressed in infected cells.

Activation of the 2-5OAS/RNase L pathway in CVB1 or HAV/18f infected FRhK-4 cells does not require induction of OAS1 or OAS2 expression

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

Kulka, Michael, E-mail: michael.kulka@fda.hhs.go; Calvo, Mona S., E-mail: mona.calvo@fda.hhs.go; Ngo, Diana T., E-mail: diana.ngo@fda.hhs.go

2009-05-25

The latent, constitutively expressed protein RNase L is activated in coxsackievirus and HAV strain 18f infected FRhK-4 cells. Endogenous oligoadenylate synthetase (OAS) from uninfected and virus infected cell extracts synthesizes active forms of the triphosphorylated 2-5A oligomer (the only known activator of RNase L) in vitro and endogenous 2-5A is detected in infected cell extracts. However, only the largest OAS isoform, OAS3, is readily detected throughout the time course of infection. While IFNbeta treatment results in an increase in the level of all three OAS isoforms in FRhK-4 cells, IFNbeta pretreatment does not affect the temporal onset or enhancement ofmore » RNase L activity nor inhibit virus replication. Our results indicate that CVB1 and HAV/18f activate the 2-5OAS/RNase L pathway in FRhK-4 cells during permissive infection through endogenous levels of OAS, but contrary to that reported for some picornaviruses, CVB1 and HAV/18f replication is insensitive to this activated antiviral pathway.« less

Gammaherpesvirus-driven plasma cell differentiation regulates virus reactivation from latently infected B lymphocytes.

PubMed

Liang, Xiaozhen; Collins, Christopher M; Mendel, Justin B; Iwakoshi, Neal N; Speck, Samuel H

2009-11-01

Gammaherpesviruses chronically infect their host and are tightly associated with the development of lymphoproliferative diseases and lymphomas, as well as several other types of cancer. Mechanisms involved in maintaining chronic gammaherpesvirus infections are poorly understood and, in particular, little is known about the mechanisms involved in controlling gammaherpesvirus reactivation from latently infected B cells in vivo. Recent evidence has linked plasma cell differentiation with reactivation of the human gammaherpesviruses EBV and KSHV through induction of the immediate-early viral transcriptional activators by the plasma cell-specific transcription factor XBP-1s. We now extend those findings to document a role for a gammaherpesvirus gene product in regulating plasma cell differentiation and thus virus reactivation. We have previously shown that the murine gammaherpesvirus 68 (MHV68) gene product M2 is dispensable for virus replication in permissive cells, but plays a critical role in virus reactivation from latently infected B cells. Here we show that in mice infected with wild type MHV68, virus infected plasma cells (ca. 8% of virus infected splenocytes at the peak of viral latency) account for the majority of reactivation observed upon explant of splenocytes. In contrast, there is an absence of virus infected plasma cells at the peak of latency in mice infected with a M2 null MHV68. Furthermore, we show that the M2 protein can drive plasma cell differentiation in a B lymphoma cell line in the absence of any other MHV68 gene products. Thus, the role of M2 in MHV68 reactivation can be attributed to its ability to manipulate plasma cell differentiation, providing a novel viral strategy to regulate gammaherpesvirus reactivation from latently infected B cells. We postulate that M2 represents a new class of herpesvirus gene products (reactivation conditioners) that do not directly participate in virus replication, but rather facilitate virus reactivation by

A case of IgG4-related lung disease complicated by asymptomatic chronic Epstein-Barr virus infection.

PubMed

Kotetsu, Yasuaki; Ikegame, Satoshi; Takebe-Akazawa, Keiko; Koga, Takaomi; Okabayashi, Kan; Takata, Shohei

2017-11-01

IgG4-related disease is characterized by IgG4-positive plasmacyte infiltration into various organs, but its etiology is not unknown. To elucidate the etiology of IgG4-related disease. We experienced an interesting case of IgG4-related lung disease complicated by chronic EB virus infection. A 70-year-old male visited our hospital due to failure of pneumonia treatment. Chest computed tomography (CT) showed consolidation in the right middle field and slight mediastinal lymphadenopathy in the subcarinal region. Lung consolidation improved with antibiotics; subcarinal lymphadenopathy progressed after 4 months. Malignant lymphoma was suspected given elevated sIL2-R levels (1862 U/mL). Patchy ground glass opacities appeared in the bilateral lung field just before surgical biopsy. He was diagnosed with IgG4-related lung disease after inspection of a pathological specimen obtained from the right upper lung and right hilar lymph node. EB virus-infected cells were also detected in the lymph node. Blood examination revealed EB virus viremia, but the patient did not present with symptoms or organ involvement. This led to a diagnosis of asymptomatic chronic EB virus infection. Recent studies have suggested an association between EB virus infection and IgG4-related diseases in the pathological exploration of surgically resected lymph nodes. Our case is the first case of IgG4-related lung disease in which EB virus infection was both pathologically and clinically proved. The present case is of particular interest in view of this newly reported association, and may serve as a fundamental report for future studies connecting EB virus infection with IgG4-related diseases. © 2016 John Wiley & Sons Ltd.

Chronic Gastritis and its Association with H. Pylori Infection.

PubMed

Fatema, J; Khan, A H; Uddin, M J; Rahman, M H; Saha, M; Safwath, S A; Alam, M J; Mamun, M A

2015-10-01

This cross sectional study was designed to see association of chronic gastritis including its type with H. pylori infection. Consecutive patients undergoing endoscopic examination having histopathological evidence of chronic gastritis were enrolled in the study and was done in Sylhet MAG Osmani Medical College from July 2011 to June 2012. Biopsies were taken from antrum, body and fundus in all patients. Histopathological examinations were done using H-E stain and for detection of H. pylori, rapid urease test, anti-H.pylori antibody test and histopathological test with modified Giemsa stain were done. Patients having results positive in at least two methods were considered infected by H. pylori. Total 80 dyspeptic patients having chronic gastritis were evaluated. Out of them 67(83.8%) had H. pylori infection and 13(16.2%) were H. pylori negative. Among all patients 57(71.2%) had pangastritis and 23(28.8%) had antral gastritis with female and male predominance respectively. H. pylori infection was present in 49(86.0%) cases of pangastritis and 18(78.3%) cases of antral gastritis. H. pylori infection was a little higher among males (34, 50.7%) females (33, 49.3%). H. pylori infection is the predominant cause of chronic gastritis and pangastritis is the major type.

Are Mucosa CD4+/CD8+ T-Cells Expressions Correlated with the Endoscopic Appearance of Chronic Gastritis Related with Helicobacter pylori Infection?

PubMed

Ratnasari, Neneng; Bayupurnama, Putut; Maduseno, Sutanto; Indrarti, Fahmi; Triwikatmani, Catharina; Harijadi, Achmad; Nurdjanah, Siti

2016-06-01

Local inflammatory processes in the gastric mucosa are followed by extensive immune cell infiltration, resulting in chronic active gastritis characterized by a marked infiltration of T(h)1 cytokine-producing CD4+ and CD8+T-cells Objective. To investigate the correlation between CD4+/CD8+ T-cells in gastric mucosa with endoscopic appearance in chronic gastritis with or without H.pylori infection. Prospective, cross sectional study is performed in a chronic dyspepsia population in July-November 2009 at Dr. Sardjito General Hospital Yogyakarta, Indonesia. The update Sydney system was used to analyze the gastroscopy appearance. Biopsy specimens were stained with HE-stain and IHC-stain. Data were analyzed by t-test, Mann-Whitney and Spearman correlation test. Number of 88 consecutive subjects are enrolled the study (50% male; 50% female), age 46±15 years; 25% H.pylori positive. The expression of CD4+ and CD8+ were higher in H.pylori negative subjects, but only the CD4+ was significant (P=0.011). A significant correlation was found between CD4+ and CD8+ in both subjects (r(Hp+)=0.62 and r(Hp-)=0.68; P<0.05). The expression of CD4+ and CD8+ in H.pylori positive showed a significant correlation with gastric lesions (r(CD4+)=-0.60; r(CD8+)=-0.42 ; P<0.05), only erosion showed a significant difference in both subjects. A positive correlation was found between CD4+ and CD8+ infiltration in both subjects with or without H.pylori infection, and a negative correlation was only found between gastric lesion with CD4+ and CD8+ infiltration in H.pylori subject.

Recent Concise Viewpoints of Chronic Active Epstein-Barr Virus Infection.

PubMed

Okano, Motohiko

2015-01-01

Chronic active Epstein-Barr virus infection (CAEBV) is characterized mainly by prolonged or intermittent fever, lymphadenopathy and hepatosplenomegaly without definite underlying diseases at the diagnosis. Patients with CAEBV also may have various life-threatening conditions including hematological, neurological, pulmonary, cardiac, digestive tract, ocular and/or dermal disorders. Additionally, during the course of illness, they often develop hematological malignancies such as T cell, NK cell or B cell lymphoproliferative disorder (LPD) and/or lymphoma. No causative pathogenetic mechanisms have been sufficiently clarified, and additionally no promising efficacious treatment was demonstrated except for the hematopoietic stem cell transplantation (HSCT) in cases who develop T cell or NK cell LPD or lymphoma. This minireview outlines the recent development for the comprehensive viewpoints of CAEBV mainly regarding to virological, immunological, pathological and therapeutical progresses.

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 Impact of Juvenile Coxsackievirus Infection on Cardiac Progenitor Cells and Postnatal Heart Development

PubMed Central

Sin, Jon; Puccini, Jenna M.; Huang, Chengqun; Konstandin, Mathias H.; Gilbert, Paul E.; Sussman, Mark A.; Gottlieb, Roberta A.; Feuer, Ralph

2014-01-01

Coxsackievirus B (CVB) is an enterovirus that most commonly causes a self-limited febrile illness in infants, but cases of severe infection can manifest in acute myocarditis. Chronic consequences of mild CVB infection are unknown, though there is an epidemiologic association between early subclinical infections and late heart failure, raising the possibility of subtle damage leading to late-onset dysfunction, or chronic ongoing injury due to inflammatory reactions during latent infection. Here we describe a mouse model of juvenile infection with a subclinical dose of coxsackievirus B3 (CVB3) which showed no evident symptoms, either immediately following infection or in adult mice. However following physiological or pharmacologically-induced cardiac stress, juvenile-infected adult mice underwent cardiac hypertrophy and dilation indicative of progression to heart failure. Evaluation of the vasculature in the hearts of adult mice subjected to cardiac stress showed a compensatory increase in CD31+ blood vessel formation, although this effect was suppressed in juvenile-infected mice. Moreover, CVB3 efficiently infected juvenile c-kit+ cells, and cardiac progenitor cell numbers were reduced in the hearts of juvenile-infected adult mice. These results suggest that the exhausted cardiac progenitor cell pool following juvenile CVB3 infection may impair the heart's ability to increase capillary density to adapt to increased load. PMID:25079373

The involvement of plasmacytoid cells in HIV infection and pathogenesis.

PubMed

Aiello, Alessandra; Giannessi, Flavia; Percario, Zulema A; Affabris, Elisabetta

2018-04-01

Plasmacytoid dendritic cells (pDCs) are a unique dendritic cell subset that are specialized in type I interferon (IFN) production. pDCs are key players in the antiviral immune response and serve as bridge between innate and adaptive immunity. Although pDCs do not represent the main reservoir of the Human Immunodeficiency Virus (HIV), they are a crucial subset in HIV infection as they influence viral transmission, target cell infection and antigen presentation. pDCs act as inflammatory and immunosuppressive cells, thus contributing to HIV disease progression. This review provides a state of art analysis of the interactions between HIV and pDCs and their potential roles in HIV transmission, chronic immune activation and immunosuppression. A thorough understanding of the roles of pDCs in HIV infection will help to improve therapeutic strategies to fight HIV infection, and will further increase our knowledge on this important immune cell subset. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Novel Model of Asymptomatic Plasmodium Parasitemia That Recapitulates Elements of the Human Immune Response to Chronic Infection

PubMed Central

Baccarella, Alyssa; Craft, Joshua F.; Boyle, Michelle J.; McIntyre, Tara I.; Wood, Matthew D.; Thorn, Kurt S.; Anidi, Chioma; Bayat, Aqieda; Chung, Me Ree; Hamburger, Rebecca; Kim, Chris Y.; Pearman, Emily; Pham, Jennifer; Tang, Jia J.; Boon, Louis; Kamya, Moses R.; Dorsey, Grant; Feeney, Margaret E.; Kim, Charles C.

2016-01-01

In humans, immunity to Plasmodium sp. generally takes the form of protection from symptomatic malaria (i.e., 'clinical immunity') rather than infection ('sterilizing immunity'). In contrast, mice infected with Plasmodium develop sterilizing immunity, hindering progress in understanding the mechanistic basis of clinical immunity. Here we present a novel model in which mice persistently infected with P. chabaudi exhibit limited clinical symptoms despite sustaining patent parasite burdens for many months. Characterization of immune responses in persistently infected mice revealed development of CD4+ T cell exhaustion, increased production of IL-10, and expansion of B cells with an atypical surface phenotype. Additionally, persistently infected mice displayed a dramatic increase in circulating nonclassical monocytes, a phenomenon that we also observed in humans with both chronic Plasmodium exposure and asymptomatic infection. Following pharmacological clearance of infection, previously persistently infected mice could not control a secondary challenge, indicating that persistent infection disrupts the sterilizing immunity that typically develops in mouse models of acute infection. This study establishes an animal model of asymptomatic, persistent Plasmodium infection that recapitulates several central aspects of the immune response in chronically exposed humans. As such, it provides a novel tool for dissection of immune responses that may prevent development of sterilizing immunity and limit pathology during infection. PMID:27583554

Infectivity of Sf-rhabdovirus variants in insect and mammalian cell lines.

PubMed

Maghodia, Ajay B; Jarvis, Donald L

2017-12-01

Sf-rhabdovirus was only recently identified as an adventitious agent of Spodoptera frugiperda (Sf) cell lines used as hosts for baculovirus vectors. As such, we still know little about its genetic variation, infectivity, and the potential impact of variation on the Sf-rhabdovirus-host interaction. Here, we characterized Sf-rhabdoviruses from two widely used Sf cell lines to confirm and extend information on Sf-rhabdovirus variation. We then used our novel Sf-rhabdovirus-negative (Sf-RVN) Sf cell line to assess the infectivity of variants with and without a 320bp X/L deletion and found both established productive persistent infections in Sf-RVN cells. We also assessed their infectivity using heterologous insect and mammalian cell lines and found neither established productive persistent infections in these cells. These results are the first to directly demonstrate Sf-rhabdoviruses are infectious for Sf cells, irrespective of the X/L deletion. They also confirm and extend previous results indicating Sf-rhabdoviruses have a narrow host range. Copyright © 2017 Elsevier Inc. All rights reserved.

IL-22 Defect During Streptococcus pneumoniae Infection Triggers Exacerbation of Chronic Obstructive Pulmonary Disease.

PubMed

Pichavant, Muriel; Sharan, Riti; Le Rouzic, Olivier; Olivier, Cécile; Hennegrave, Florence; Rémy, Gaëlle; Pérez-Cruz, Magdiel; Koné, Bachirou; Gosset, Pierre; Just, Nicolas; Gosset, Philippe

2015-11-01

Progression of chronic obstructive pulmonary disease (COPD) is linked to episodes of exacerbations caused by bacterial infections due to Streptococcus pneumoniae. Our objective was to identify during COPD, factors of susceptibility to bacterial infections among cytokine network and their role in COPD exacerbations. S. pneumoniae was used to sub-lethally challenge mice chronically exposed to air or cigarette smoke (CS) and to stimulate peripheral blood mononuclear cells (PBMC) from non-smokers, smokers and COPD patients. The immune response and the cytokine production were evaluated. Delayed clearance of the bacteria and stronger lung inflammation observed in infected CS-exposed mice were associated with an altered production of IL-17 and IL-22 by innate immune cells. This defect was related to a reduced production of IL-1β and IL-23 by antigen presenting cells. Importantly, supplementation with recombinant IL-22 restored bacterial clearance in CS-exposed mice and limited lung alteration. In contrast with non-smokers, blood NK and NKT cells from COPD patients failed to increase IL-17 and IL-22 levels in response to S. pneumoniae, in association with a defect in IL-1β and IL-23 secretion. This study identified IL-17 and IL-22 as susceptibility factors in COPD exacerbation. Therefore targeting such cytokines could represent a potent strategy to control COPD exacerbation.

FoxP3+ CD25+ CD8+ T-Cell Induction during Primary Simian Immunodeficiency Virus Infection in Cynomolgus Macaques Correlates with Low CD4+ T-Cell Activation and High Viral Load▿

PubMed Central

Karlsson, Ingrid; Malleret, Benoît; Brochard, Patricia; Delache, Benoît; Calvo, Julien; Le Grand, Roger; Vaslin, Bruno

2007-01-01

The early immune response fails to prevent the establishment of chronic human immunodeficiency virus (HIV) infection but may influence viremia during primary infection, thereby possibly affecting long-term disease progression. CD25+ FoxP3+ regulatory T cells may contribute to HIV/simian immunodeficiency virus (SIV) pathogenesis by suppressing efficient antiviral responses during primary infection, favoring high levels of viral replication and the establishment of chronic infection. In contrast, they may decrease immune activation during chronic infection. CD4+ regulatory T cells have been studied in the most detail, but CD8+ CD25+ FoxP3+ T cells also have regulatory properties. We monitored the dynamics of CD25+ FoxP3+ T cells during primary and chronic SIVmac251 infection in cynomolgus macaques. The number of peripheral CD4+ CD25+ FoxP3+ T cells paralleled that of memory CD4+ T cells, with a rapid decline during primary infection followed by a rebound to levels just below baseline and gradual depletion during the course of infection. No change in the proportion of CD25+ FoxP3+ T cells was observed in peripheral lymph nodes. A small number of CD4+ CD25+ FoxP3+ T cells at set point was associated with a high plasma viral load. In contrast, peripheral CD8+ CD25+ FoxP3+ T cells were induced a few days after peak plasma viral load during primary infection. The number of these cells was positively correlated with viral load and negatively correlated with CD4+ T-cell activation, SIV antigen-specific proliferative responses during primary infection, and plasma viral load at set point, with large numbers of CD8+ CD25+ FoxP3+ T cells being indicative of a poor prognosis. PMID:17898053

Natural history of chronic hepatitis B virus infection.

PubMed

Busch, Katrin; Thimme, Robert

2015-02-01

Hepatitis B virus infection represents a major global health problem. Currently, there are more than 240 million chronically infected people worldwide. The development of chronic hepatitis B virus-mediated liver disease may lead to liver fibrosis, cirrhosis and eventually hepatocellular carcinoma. Recently, the discovery of the viral entry receptor sodium taurocholate cotransporting polypeptide has facilitated new approaches for a better understanding of viral physiopathology. Hopefully, these novel insights may give rise to the development of more effective antiviral therapy concepts during the next years. In this review, we will discuss the natural history of hepatitis B virus infection including the viral biology, the clinical course of infection and the role of the immune response.

Chronic active Epstein-Barr virus infection in an adult with no detectable immune deficiency.

PubMed

de Boer, M; Mol, M J T M; Bogman, M J J T; Galama, J M D; Raymakers, R A P

2003-11-01

Epstein-Barr virus (EBV) establishes lifelong latent infection. In some patients the host-virus balance is disturbed, resulting in a chronic active EBV infection. The following case illustrates the difficulty in diagnosing and treating chronic EBV infection. A 30-year-old woman was referred because of recurrent swellings of lymphatic tissue of both eyelids, orbit and lymph nodes and general malaise since the age of 19. In the past, repeated biopsies showed MALT lymphoma and nonspecific lymphoid infiltrations. Now, a biopsy of an axillary lymph node showed paracortical hyperplasia with a polymorphous polyclonal lymphoid proliferation, and large numbers of EBV-encoded small RNA (EBER) positive cells, consistent with EBV infection. Laboratory investigation showed a high EBV viral load. No evidence of immunodeficiency was found. Chronic active EBV infection (CAEBV) was diagnosed. Treatment with high-dose acyclovir did not significantly reduce the viral load. Rituximab was given in an attempt to reduce the amount of EBV-infected B lymphocytes. However, soon after the second dose the patient died of a sub-arachnoidal haemorrhage. This case report illustrates CAEBV as a rare manifestation of EBV-induced disease, which will be detected more frequently with the use of EBV-EBER hybridisation of lymph nodes and polymerase chain reaction (PCR) for EBV DNA. The prognosis is poor with no established therapeutic strategies.

Isolation of single Chlamydia-infected cells using laser microdissection.

PubMed

Podgorny, Oleg V; Polina, Nadezhda F; Babenko, Vladislav V; Karpova, Irina Y; Kostryukova, Elena S; Govorun, Vadim M; Lazarev, Vassili N

2015-02-01

Chlamydia are obligate intracellular parasites of humans and animals that cause a wide range of acute and chronic infections. To elucidate the genetic basis of chlamydial parasitism, several approaches for making genetic modifications to Chlamydia have recently been reported. However, the lack of the available methods for the fast and effective selection of genetically modified bacteria restricts the application of genetic tools. We suggest the use of laser microdissection to isolate of single live Chlamydia-infected cells for the re-cultivation and whole-genome sequencing of single inclusion-derived Chlamydia. To visualise individual infected cells, we made use of the vital labelling of inclusions with the fluorescent Golgi-specific dye BODIPY® FL C5-ceramide. We demonstrated that single Chlamydia-infected cells isolated by laser microdissection and placed onto a host cell monolayer resulted in new cycles of infection. We also demonstrated the successful use of whole-genome sequencing to study the genomic variability of Chlamydia derived from a single inclusion. Our work provides the first evidence of the successful use of laser microdissection for the isolation of single live Chlamydia-infected cells, thus demonstrating that this method can help overcome the barriers to the fast and effective selection of Chlamydia. Copyright © 2014 Elsevier B.V. All rights reserved.

B cells in chronically hepatitis C virus-infected individuals lack a virus-induced mutation signature in the TP53, CTNNB1, and BCL6 genes.

PubMed

Tucci, Felicia Anna; Broering, Ruth; Johansson, Patricia; Schlaak, Joerg F; Küppers, Ralf

2013-03-01

Hepatitis C virus (HCV) is considered to have a causative role in B-cell lymphoproliferative diseases, including B-cell lymphomas, in chronic virus carriers. Previous data from in vitro HCV-infected B-cell lines and peripheral blood mononuclear cells from HCV-positive individuals suggested that HCV might have a direct mutagenic effect on B cells, inducing mutations in the tumor suppressor gene TP53 and the proto-oncogenes BCL6 and CTNNB1 (β-catenin). To clarify whether HCV indeed has a mutagenic effect on B cells in vivo, we analyzed naive and memory B cells from the peripheral blood of four chronic HCV carriers and intrahepatic B cells from the livers of two HCV-positive patients for mutations in the three reported target genes. However, no mutations were found in the TP53 and CTNNB1 genes. For BCL6, which is a physiological target of the somatic hypermutation process in germinal-center B cells, the mutation levels identified were not higher than those reported in the respective B-cell subsets in healthy individuals. Hence, we conclude that in chronic HCV carriers, the virus does not generally induce mutations in the cancer-related genes TP53, CTNNB1, and BCL6 in B cells. Based on these findings, new targets have to be investigated as potential mediators of HCV-associated B-cell lymphomagenesis.

Therapeutic Vaccines for Chronic Infections

NASA Astrophysics Data System (ADS)

Autran, Brigitte; Carcelain, Guislaine; Combadiere, Béhazine; Debre, Patrice

2004-07-01

Therapeutic vaccines aim to prevent severe complications of a chronic infection by reinforcing host defenses when some immune control, albeit insufficient, can already be demonstrated and when a conventional antimicrobial therapy either is not available or has limited efficacy. We focus on the rationale and challenges behind this still controversial strategy and provide examples from three major chronic infectious diseases-human immunodeficiency virus, hepatitis B virus, and human papillomavirus-for which the efficacy of therapeutic vaccines is currently being evaluated.

Persistent RNA virus infections: do PAMPS drive chronic disease?

PubMed Central

McCarthy, Mary K.; Morrison, Thomas E.

2017-01-01

Chronic disease associated with persistent RNA virus infections represents a key public health concern. While human immunodeficiency virus-1 and hepatitis C virus are perhaps the most well-known examples of persistent RNA viruses that cause chronic disease, evidence suggests that many other RNA viruses, including re-emerging viruses such as chikungunya virus, Ebola virus and Zika virus, establish persistent infections. The mechanisms by which RNA viruses drive chronic disease are poorly understood. Here, we discuss how the persistence of viral RNA may drive chronic disease manifestations via the activation of RNA sensing pathways. PMID:28214732

Utilization of human DC-SIGN and L-SIGN for entry and infection of host cells by the New World arenavirus, Junín virus

PubMed Central

Belouzard, Sandrine; Cordo, Sandra M.; Candurra, Nélida A.; Whittaker, Gary R.

2014-01-01

The target cell tropism of enveloped viruses is regulated by interactions between viral proteins and cellular receptors determining susceptibility at a host cell, tissue or species level. However, a number of additional cell-surface moieties can also bind viral envelope glycoproteins and could act as capture receptors, serving as attachment factors to concentrate virus particles on the cell surface, or to disseminate the virus infection to target organs or susceptible cells within the host. Here, we used Junín virus (JUNV) or JUNV glycoprotein complex (GPC)-pseudotyped particles to study their ability to be internalized by the human C-type lectins hDC- or hL-SIGN. Our results provide evidence that hDC- and hL-SIGN can mediate the entry of Junín virus into cells, and may play an important role in virus infection and dissemination in the host. PMID:24183720

The art of persistence-the secrets to Burkholderia chronic infections.

PubMed

Lewis, Eric R G; Torres, Alfredo G

2016-08-01

The Gram-negative proteobacteria genus Burkholderia encompasses multiple bacterial species that are pathogenic to humans and other vertebrates. Two pathogenic species of interest within this genus are Burkholderia pseudomallei (Bpm) and the B. cepacia complex (Bcc); the former is the causative agent of melioidosis in humans and other mammals, and the latter is associated with pneumonia in immunocompromised patients. One understudied and shared characteristic of these two pathogenic groups is their ability to persist and establish chronic infection within the host. In this review, we will explore the depth of knowledge about chronic infections caused by persistent Bpm and Bcc. We examine the host risk factors and immune responses associated with more severe chronic infections. We also discuss host adaptation and phenotypes associated with persistent Burkholderia species. Lastly, we survey how other intracellular bacteria associated with chronic infections are combatted and explore possible future applications to target Burkholderia Our goal is to highlight understudied areas that should be addressed for a more thorough understanding of chronic Burkholderia infections and how to combat them. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Functional restoration of HCV-specific CD8 T cells by PD-1 blockade is defined by PD-1 expression and compartmentalization.

PubMed

Nakamoto, Nobuhiro; Kaplan, David E; Coleclough, Jennifer; Li, Yun; Valiga, Mary E; Kaminski, Mary; Shaked, Abraham; Olthoff, Kim; Gostick, Emma; Price, David A; Freeman, Gordon J; Wherry, E John; Chang, Kyong-Mi

2008-06-01

The immunoinhibitory receptor programmed death-1 (PD-1) is up-regulated on dysfunctional virus-specific CD8 T cells during chronic viral infections, and blockade of PD-1/PD-ligand (PD-L) interactions can restore their function. As hepatitis C virus (HCV) persists in the liver with immune-mediated disease pathogenesis, we examined the role of PD-1/PD-L pathway in antigen-specific CD8 T-cell dysfunction in the liver and blood of HCV-infected patients. PD-1 expression and function of circulating CD8 T cells specific for HCV, Epstein-Barr virus, and influenza virus were examined ex vivo and following antigenic stimulation in vitro in patients with acute, chronic, and resolved HCV infection using class I tetramers and flow cytometry. Intrahepatic CD8 T cells were examined from liver explants of chronically HCV-infected transplant recipients. Intrahepatic HCV-specific CD8 T cells from chronically HCV-infected patients were highly PD-1 positive, profoundly dysfunctional, and unexpectedly refractory to PD-1/PD-L blockade, contrasting from circulating PD-1-intermediate HCV-specific CD8 T cells with responsiveness to PD-1/PD-L blockade. This intrahepatic functional impairment was HCV-specific and directly associated with the level of PD-1 expression. Highly PD-1-positive intrahepatic CD8 T cells were more phenotypically exhausted with increased cytotoxic T-lymphocyte antigen 4 and reduced CD28 and CD127 expression, suggesting that active antigen-specific stimulation in the liver induces a profound functional exhaustion not reversible by PD-1/PD-L blockade alone. HCV-specific CD8 T-cell dysfunction and responsiveness to PD-1/PD-L blockade are defined by their PD-1 expression and compartmentalization. These findings provide new and clinically relevant insight to differential antigen-specific CD8 T-cell exhaustion and their functional restoration.

Functional restoration of HCV-specific CD8 T-cells by PD1 blockade is defined by PD1 expression and compartmentalization

PubMed Central

Nakamoto, Nobuhiro; Kaplan, David E.; Coleclough, Jennifer; Li, Yun; Kaminski, Mary; Shaked, Abraham; Olthoff, Kim; Gostick, Emma; Price, David A.; Freeman, Gordon J.; Wherry, E. John; Chang, Kyong-Mi

2008-01-01

Background & Aims The immuno-inhibitory receptor Programmed Death-1 (PD-1) is upregulated on dysfunctional virus-specific CD8 T-cells during chronic viral infections and blockade of PD-1:PD-ligand (PD-L) interactions can restore their function. As hepatitis C virus (HCV) persists in the liver with immune-mediated disease pathogenesis, we examined the role of PD1/PD-L pathway in antigen-specific CD8 T-cell dysfunction in the liver and blood of HCV-infected patients. Methods PD-1 expression and function of circulating CD8 T-cells specific for HCV, EBV and Flu were examined ex vivo and following antigenic stimulation in vitro in patients with acute, chronic and resolved HCV infection using class I tetramers and flow cytometry. Intrahepatic CD8 T-cells were examined from liver explants of chronically HCV-infected transplant recipients. Results Intrahepatic HCV-specific CD8 T-cells from chronically HCV-infected patients were highly PD-1-positive, profoundly dysfunctional and unexpectedly refractory to PD-1:PD-L blockade, contrasting from circulating PD-1-intermediate HCV-specific CD8 T-cells with responsiveness to PD-1:PD-L blockade. This intrahepatic functional impairment was HCV-specific and directly associated with the level of PD-1 expression. Highly PD-1-positive intrahepatic CD8 T-cells were more phenotypically exhausted with increased cytotoxic T-lymphocyte antigen 4 (CTLA-4) and reduced CD28 and CD127 expression, suggesting that active antigen-specific stimulation in the liver induces a profound functional exhaustion not reversible by PD-1:PD-L blockade alone. Conclusion HCV-specific CD8 T-cell dysfunction and responsiveness to PD-1:PD-L blockade are defined by their PD-1 expression and compartmentalization. These findings provide new and clinically relevant insight to differential antigen-specific CD8 T-cell exhaustion and their functional restoration. PMID:18549878

Prevalence of cutaneous viral infections in incident cutaneous squamous cell carcinoma detected among chronic lymphocytic leukemia and hematopoietic stem cell transplant patients.

PubMed

Hampras, Shalaka S; Locke, Frederick L; Chavez, Julio C; Patel, Nishit S; Giuliano, Anna R; Miller, Kyle; Gheit, Tarik; Tommasino, Massimo; Rollison, Dana E

2018-04-01

The role of cutaneous viral infections in the development of non-melanoma skin cancer (NMSC), including cutaneous squamous cell carcinoma (SCC), among chronic lymphocytic leukemia (CLL) and blood and marrow transplant (BMT) patients is not established. CLL (n = 977) and BMT (n = 3587) patients treated at the Moffitt Cancer Center were included in a retrospective cohort study. Human papillomavirus (HPV) and human polyomavirus (HPyV) DNA were examined in a subset of incident SCC tumors. Five-year cumulative incidence of NMSC was 1.42% in both BMT (n = 31 NMSCs) and CLL (n = 18 NMSCs) cohorts. Of the nine SCC tumors examined from each cohort, 22.2% and 33.3% were positive for viral DNA in the transplant (HPV 65, MCV) and CLL (HPV 38, HPV 15, HPyV6) cohort, respectively. Enhanced skin cancer screening of BMT/CLL patients should be conducted to better capture incident NMSCs and examine the role of viral infections in these tumors.

[Cardiac neuronal depopulation in hamsters (Mesocricetus auratus) chronically infected with Trypanosoma cruzi].

PubMed

Chapadeiro, E; Silva, E L; Silva, A C; Fernandes, P; Ramirez, L E

1999-01-01

The aim of this study was to obtain an experimental animal model of destruction of cardiac neurons in order to investigate the behavior of the cardiac nervous system of hamsters chronically infected with Trypanosoma cruzi. We counted the neuronal cells of the cardiac autonomic nervous plexus in hamsters inoculated with 35,000 blood forms of three different T. cruzi strains and killed 5, 8 and 10 months after infection. We showed for the first time severe neuronal destruction in an experimental animal model with characteristics similar to those observed in human Chagas'disease.

Chronic Trichuris muris Infection Decreases Diversity of the Intestinal Microbiota and Concomitantly Increases the Abundance of Lactobacilli.

PubMed

Holm, Jacob Bak; Sorobetea, Daniel; Kiilerich, Pia; Ramayo-Caldas, Yuliaxis; Estellé, Jordi; Ma, Tao; Madsen, Lise; Kristiansen, Karsten; Svensson-Frej, Marcus

2015-01-01

The intestinal microbiota is vital for shaping the local intestinal environment as well as host immunity and metabolism. At the same time, epidemiological and experimental evidence suggest an important role for parasitic worm infections in maintaining the inflammatory and regulatory balance of the immune system. In line with this, the prevalence of persistent worm infections is inversely correlated with the incidence of immune-associated diseases, prompting the use of controlled parasite infections for therapeutic purposes. Despite this, the impact of parasite infection on the intestinal microbiota, as well as potential downstream effects on the immune system, remain largely unknown. We have assessed the influence of chronic infection with the large-intestinal nematode Trichuris muris, a close relative of the human pathogen Trichuris trichiura, on the composition of the murine intestinal microbiota by 16S ribosomal-RNA gene-based sequencing. Our results demonstrate that persistent T. muris infection dramatically affects the large-intestinal microbiota, most notably with a drop in the diversity of bacterial communities, as well as a marked increase in the relative abundance of the Lactobacillus genus. In parallel, chronic T. muris infection resulted in a significant shift in the balance between regulatory and inflammatory T cells in the intestinal adaptive immune system, in favour of inflammatory cells. Together, these data demonstrate that chronic parasite infection strongly influences the intestinal microbiota and the adaptive immune system. Our results illustrate the complex interactions between these factors in the intestinal tract, and contribute to furthering the understanding of this interplay, which is of crucial importance considering that 500 million people globally are suffering from these infections and their potential use for therapeutic purposes.

Programed death-1/programed death-ligand 1 expression in lymph nodes of HIV infected patients: results of a pilot safety study in rhesus macaques using anti–programed death-ligand 1 (Avelumab)

PubMed Central

Gill, Amanda L.; Green, Samantha A.; Abdullah, Shahed; Le Saout, Cecile; Pittaluga, Stefania; Chen, Hui; Turnier, Refika; Lifson, Jeffrey; Godin, Steven; Qin, Jing; Sneller, Michael C.; Cuillerot, Jean-Marie; Sabzevari, Helen; Lane, H. Clifford; Catalfamo, Marta

2016-01-01

Objective: The programed death-1 (PD1)/programed death-ligand 1 (PD-L1) pathway plays a critical role in balancing immunity and host immunopathology. During chronic HIV/SIV infection, there is persistent immune activation accompanied by accumulation of virus-specific cells with terminally differentiated phenotypes and expression of regulatory receptors such as PD1. These observations led us to hypothesize that the PD1/PD-L1 pathway contributes to the functional dysregulation and ineffective viral control, and its blockade may be a potential immunotherapeutic target. Methods: Lymph node biopsies from HIV-infected patients (n = 23) were studied for expression of PD1 and PD-L1. In addition, we assessed the safety and biological activity of a human anti-PD-L1 antibody (Avelumab) in chronically SIV-infected rhesus macaques. Results: PD-L1 expression was observed in cells with myloid/macrophage morphology in HIV-infected lymph nodes. Administration of anti-PD-L1 was well tolerated, and no changes in body weights, hematologic, or chemistry parameters were observed during the study. Blockade of PD-L1 led to a trend of transient viral control after discontinuation of treatment. Conclusion: Administration of anti-PD-L1 in chronic SIV-infected rhesus macaques was well tolerated. Overall, these data warrant further investigation to assess the efficacy of anti-PD-L1 treatment on viral control in chronic SIV infection as a prelude to such therapy in humans. PMID:27490642

Programed death-1/programed death-ligand 1 expression in lymph nodes of HIV infected patients: results of a pilot safety study in rhesus macaques using anti-programed death-ligand 1 (Avelumab).

PubMed

Gill, Amanda L; Green, Samantha A; Abdullah, Shahed; Le Saout, Cecile; Pittaluga, Stefania; Chen, Hui; Turnier, Refika; Lifson, Jeffrey; Godin, Steven; Qin, Jing; Sneller, Michael C; Cuillerot, Jean-Marie; Sabzevari, Helen; Lane, H Clifford; Catalfamo, Marta

2016-10-23

The programed death-1 (PD1)/programed death-ligand 1 (PD-L1) pathway plays a critical role in balancing immunity and host immunopathology. During chronic HIV/SIV infection, there is persistent immune activation accompanied by accumulation of virus-specific cells with terminally differentiated phenotypes and expression of regulatory receptors such as PD1. These observations led us to hypothesize that the PD1/PD-L1 pathway contributes to the functional dysregulation and ineffective viral control, and its blockade may be a potential immunotherapeutic target. Lymph node biopsies from HIV-infected patients (n = 23) were studied for expression of PD1 and PD-L1. In addition, we assessed the safety and biological activity of a human anti-PD-L1 antibody (Avelumab) in chronically SIV-infected rhesus macaques. PD-L1 expression was observed in cells with myloid/macrophage morphology in HIV-infected lymph nodes. Administration of anti-PD-L1 was well tolerated, and no changes in body weights, hematologic, or chemistry parameters were observed during the study. Blockade of PD-L1 led to a trend of transient viral control after discontinuation of treatment. Administration of anti-PD-L1 in chronic SIV-infected rhesus macaques was well tolerated. Overall, these data warrant further investigation to assess the efficacy of anti-PD-L1 treatment on viral control in chronic SIV infection as a prelude to such therapy in humans.

Moxifloxacin in Preventing Bacterial Infections in Patients Who Have Undergone Donor Stem Cell Transplant

ClinicalTrials.gov

2017-05-07

Breast Cancer; Chronic Myeloproliferative Disorders; Gestational Trophoblastic Tumor; Infection; Leukemia; Lymphoma; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Myelodysplastic/Myeloproliferative Neoplasms; Neuroblastoma; Ovarian Cancer; Testicular Germ Cell Tumor

Whole transcriptome profiling reveals major cell types in the cellular immune response against acute and chronic active Epstein-Barr virus infection.

PubMed

Zhong, Huaqing; Hu, Xinran; Janowski, Andrew B; Storch, Gregory A; Su, Liyun; Cao, Lingfeng; Yu, Jinsheng; Xu, Jin

2017-12-19

Epstein-Barr virus (EBV) is a common human pathogen that infects over 95% of the population worldwide. In the present study, the whole transcriptome microarray data were generated from peripheral blood mononuclear cells from Chinese children with acute infectious mononucleosis (AIM) and chronic active EBV infection (CAEBV) that were also compared with a publicly available microarray dataset from a study of American college students with AIM. Our study characterized for the first time a broad spectrum of molecular signatures in AIM and CAEBV. The key findings from the transcriptome profiling were validated with qPCR and flow cytometry assays. The most important finding in our study is the discovery of predominant γδ TCR expression and γδ T cell expansion in AIM. This finding, in combination with the striking up-regulation of CD3, CD8 and CD94, suggests that CD8+ T cells and CD94+ NK cells may play a major role in AIM. Moreover, the unique up-regulation of CD64A/B and its significant correlation with the monocyte marker CD14 was observed in CAEBV and that implies an important role of monocytes in CAEBV. In conclusion, our study reveals major cell types (particularly γδ T cells) in the host cellular immune response against AIM and CAEBV.

CXCL10 Is Required to Maintain T-Cell Populations and to Control Parasite Replication during Chronic Ocular Toxoplasmosis

PubMed Central

Norose, Kazumi; Kikumura, Akitoshi; Luster, Andrew D.; Hunter, Christopher A.

2011-01-01

Purpose. Toxoplasma gondii is a major cause of ocular disease, which can lead to permanent vision loss in humans. T cells are critically involved in parasite control, but little is known about the molecules that promote T-cell trafficking and migration in the retina. Thus, the aim of this study was to image and dissect the T-cell response during chronic toxoplasmic retinochoroiditis. Methods. C57BL/6 mice were infected with the Me49 strain of T. gondii, and T cells that infiltrated the eye were analyzed by flow cytometry and imaged using multiphoton microscopy. IFN-γ, CXCL9, CXCL10, and CXCR3 mRNA levels were measured by real-time PCR. To investigate the role of CXCL10, mice were treated with anti–CXCL10 antibodies, and histopathology and immunohistochemistry were performed to monitor changes in pathology, cellular infiltration, and parasite burden in the eye. Results. Infection with T. gondii leads to the infiltration of highly activated motile T cells into the eye. These cells express CXCR3 and are capable of producing IFN-γ and TNF-α, and CD8+ T cells express granzyme B. The expression of CXCL9 and CXCL10 in the retina was significantly upregulated during chronic infection. Treatment of chronically infected mice with anti–CXCL10 antibodies led to decreases in the numbers of CD3+, CD4+, and CD8+ T cells and the amount of IFN-γ mRNA expression in the retina and an increase in replicating parasites and ocular pathology. Conclusions. The maintenance of the T-cell response and the control of T. gondii in the eye during chronic infection is dependent on CXCL10. PMID:20811054

Beneficial Effects of cART Initiated during Primary and Chronic HIV-1 Infection on Immunoglobulin-Expression of Memory B-Cell Subsets

PubMed Central

Pensieroso, Simone; Tolazzi, Monica; Chiappetta, Stefania; Nozza, Silvia; Lazzarin, Adriano; Tambussi, Giuseppe; Scarlatti, Gabriella

2015-01-01

Introduction During HIV-1 infection the B-cell compartment undergoes profound changes towards terminal differentiation, which are only partially restored by antiretroviral therapy (cART). Materials and Methods To investigate the impact of infection as early as during primary HIV-1 infection (PHI) we assessed distribution of B-cell subsets in 19 PHI and 25 chronic HIV-1-infected (CHI) individuals before and during 48 weeks of cART as compared to healthy controls (n = 23). We also analysed Immunoglobulin-expression of memory B-cell subsets to identify alterations in Immunoglobulin-maturation. Results Determination of B-cell subsets at baseline showed that total and Naive B-cells were decreased whereas Activated Memory (AM), Tissue-like Memory (TLM) B-cells and Plasma cells were increased in both PHI and CHI patients. After 4 weeks of cART total B-cells increased, while AM, TLM B-cells and Plasma cells decreased, although without reaching normal levels in either group of individuals. This trend was maintained until week 48, though only total B-cells normalized in both PHI and CHI. Resting Memory (RM) B-cells were preserved since baseline. This subset remained stable in CHI, while was expanded by an early initiation of cART during PHI. Untreated CHI patients showed IgM-overexpression at the expenses of switched (IgM-IgD-) phenotypes of the memory subsets. Interestingly, in PHI patients a significant alteration of Immunoglobulin-expression was evident at BL in TLM cells, and after 4 weeks, despite treatment, in AM and RM subsets. After 48 weeks of therapy, Immunoglobulin-expression of AM and RM almost normalized, but remained perturbed in TLM cells in both groups. Conclusions In conclusion, aberrant activated and exhausted B-cell phenotypes rose already during PHI, while most of the alterations in Ig-expression seen in CHI appeared later, despite 4 weeks of effective cART. After 48 weeks of cART B-cell subsets distribution improved although without full normalization

Involvement of matrix metalloproteinases in chronic Q fever.

PubMed

Jansen, A F M; Schoffelen, T; Textoris, J; Mege, J L; Bleeker-Rovers, C P; Roest, H I J; Wever, P C; Joosten, L A B; Netea, M G; van de Vosse, E; van Deuren, M

2017-07-01

Chronic Q fever is a persistent infection with the intracellular Gram-negative bacterium Coxiella burnetii, which can lead to complications of infected aneurysms. Matrix metalloproteinases (MMPs) cleave extracellular matrix and are involved in infections as well as aneurysms. We aimed to study the role of MMPs in the pathogenesis of chronic Q fever. We investigated gene expression of MMPs through microarray analysis and MMP production with ELISA in C. burnetii-stimulated peripheral blood mononuclear cells (PBMCs) of patients with chronic Q fever and healthy controls. Twenty single nucleotide polymorphisms (SNPs) of MMP and tissue inhibitor of MMP genes were genotyped in 139 patients with chronic Q fever and 220 controls with similar cardiovascular co-morbidity. Additionally, circulating MMPs levels in patients with chronic Q fever were compared with those in cardiovascular controls with and without a history of past Q fever. In healthy controls, the MMP pathway involving four genes (MMP1, MMP7, MMP10, MMP19) was significantly up-regulated in C. burnetii-stimulated but not in Escherichia coli lipopolysaccharide -stimulated PBMCs. Coxiella burnetii induced MMP-1 and MMP-9 production in PBMCs of healthy individuals (both p<0.001), individuals with past Q fever (p<0.05, p<0.01, respectively) and of patients with chronic Q fever (both p<0.001). SNPs in MMP7 (rs11568810) (p<0.05) and MMP9 (rs17576) (p<0.05) were more common in patients with chronic Q fever. Circulating MMP-7 serum levels were higher in patients with chronic Q fever (median 33.5 ng/mL, interquartile range 22.3-45.7 ng/mL) than controls (20.6 ng/mL, 15.9-33.8 ng/mL). Coxiella burnetii-induced MMP production may contribute to the development of chronic Q fever. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Transcriptional profiling of Epstein–Barr virus (EBV) genes and host cellular genes in nasal NK/T-cell lymphoma and chronic active EBV infection

PubMed Central

Zhang, Y; Ohyashiki, J H; Takaku, T; Shimizu, N; Ohyashiki, K

2006-01-01

Nasal NK/T-cell lymphoma is an aggressive subtype of non-Hodgkin lymphoma (NHL) that is closely associated with Epstein–Barr virus (EBV). The clonal expansion of EBV-infected NK or T cells is also seen in patients with chronic active EBV (CAEBV) infection, suggesting that two diseases might share a partially similar mechanism by which EBV affects host cellular gene expression. To understand the pathogenesis of EBV-associated NK/T-cell lymphoproliferative disorders (LPD) and design new therapies, we employed a novel EBV DNA microarray to compare patterns of EBV expression in six cell lines established from EBV-associated NK/T-cell LPD. We found that expression of BZLF1, which encodes the immediate-early gene product Zta, was expressed in SNK/T cells and the expression levels were preferentially high in cell lines from CAEBV infection. We also analyzsd the gene expression patterns of host cellular genes using a human oligonucleotide DNA microarray. We identified a subset of pathogenically and clinically relevant host cellular genes, including TNFRSF10D, CDK2, HSPCA, IL12A as a common molecular biological properties of EBV-associated NK/T-cell LPD and a subset of genes, such as PDCD4 as a putative contributor for disease progression. This study describes a novel approach from the aspects of viral and host gene expression, which could identify novel therapeutic targets in EBV-associated NK/T-cell LPD. PMID:16449999

Characterization of host proteins interacting with the lymphocytic choriomeningitis virus L protein.

PubMed

Khamina, Kseniya; Lercher, Alexander; Caldera, Michael; Schliehe, Christopher; Vilagos, Bojan; Sahin, Mehmet; Kosack, Lindsay; Bhattacharya, Anannya; Májek, Peter; Stukalov, Alexey; Sacco, Roberto; James, Leo C; Pinschewer, Daniel D; Bennett, Keiryn L; Menche, Jörg; Bergthaler, Andreas

2017-12-01

RNA-dependent RNA polymerases (RdRps) play a key role in the life cycle of RNA viruses and impact their immunobiology. The arenavirus lymphocytic choriomeningitis virus (LCMV) strain Clone 13 provides a benchmark model for studying chronic infection. A major genetic determinant for its ability to persist maps to a single amino acid exchange in the viral L protein, which exhibits RdRp activity, yet its functional consequences remain elusive. To unravel the L protein interactions with the host proteome, we engineered infectious L protein-tagged LCMV virions by reverse genetics. A subsequent mass-spectrometric analysis of L protein pulldowns from infected human cells revealed a comprehensive network of interacting host proteins. The obtained LCMV L protein interactome was bioinformatically integrated with known host protein interactors of RdRps from other RNA viruses, emphasizing interconnected modules of human proteins. Functional characterization of selected interactors highlighted proviral (DDX3X) as well as antiviral (NKRF, TRIM21) host factors. To corroborate these findings, we infected Trim21-/- mice with LCMV and found impaired virus control in chronic infection. These results provide insights into the complex interactions of the arenavirus LCMV and other viral RdRps with the host proteome and contribute to a better molecular understanding of how chronic viruses interact with their host.

Role of Bruton’s Tyrosine Kinase inhibitors in HIV-1 infected cells

PubMed Central

Guendel, Irene; Iordanskiy, Sergey; Sampey, Gavin C; Van Duyne, Rachel; Calvert, Valerie; Petricoin, Emanuel; Saifuddin, Mohammed; Kehn-Hall, Kylene; Kashanchi, Fatah

2015-01-01

Many cellular cofactors have been documented to be critical for various stages of viral replication. Using high throughput proteomic assays, we have previously identified Bruton’s tyrosine kinase (BTK) as a host protein that was uniquely up-regulated in the plasma membrane of HIV-1 infected T-cells. Here, we have further characterized the BTK expression in HIV-1 infection and show that this cellular factor is specifically expressed in infected myeloid cells. Significant up-regulation of the phosphorylated form of BTK was observed in infected cells. Using size exclusion chromatography, we found BTK to be virtually absent in the uninfected U937 cells, however new BTK protein complexes were identified and distributed in both high molecular weight (~600 kDa) and a small molecular weight complex (~60–120 kDa) in the infected U1 cells. BTK levels were highest in cells either chronically expressing virus or induced/infected myeloid cells and that BTK translocated to the membrane following induction of the infected cells. BTK knockdown in HIV-1 infected cells using siRNA resulted in selective death of infected, but not uninfected, cells. Using BTK specific antibody and small molecule inhibitors including LFM-A13 and a FDA approved compound, Ibrutinib (PCI – 32765), we have found that HIV-1 infected cells are sensitive to apoptotic cell death and result in a decrease in virus production. Overall, our data suggests that HIV-1 infected cells are sensitive to treatments targeting BTK expressed in infected cells. PMID:25672887

Cellular Profile and Expression of Immunologic Markers in Chronic Apical Periodontitis from HIV-infected Patients Undergoing Highly Active Antiretroviral Therapy.

PubMed

Gama, Túlio Gustavo Veiga; Pires, Fabio Ramoa; Armada, Luciana; Gonçalves, Lucio Souza

2016-06-01

This study tested the hypothesis that the inflammatory cell profile (CD3-, CD4-, CD8-, CD20-, and CD68-positive cells) and the expression of immunologic markers (tumor necrosis factor α, interferon-γ, interleukin-6, and interleukin-18) in chronic apical periodontitis are the same between non-HIV-infected patients and HIV-infected patients undergoing highly active antiretroviral therapy (HAART). Thirty-four surgically excised chronic apical periodontitis lesions were sampled from 34 patients (17 HIV-infected and 17 non-HIV-infected). The lesions were extracted from teeth with no previous endodontic treatment. All HIV-infected patients were undergoing HAART. The specimens were submitted to histopathologic and immunohistochemical analyses by using an optical microscope. Immunoexpression was graded into 2 levels, focal to weak and moderate to strong. The χ(2), Fisher exact, and Mann-Whitney tests were used to analyze all significant differences between groups. Periapical cysts represented 70.6% and 52.9% of the lesions in the HIV-infected and non-HIV-infected groups, respectively; however, no statistically significant difference was observed (P = .481). There were no statistically significant differences between groups for the inflammatory cell profile and for any of the immunologic markers (P > .05). There are no statistically significant differences of the cellular profile and expression of immunologic markers in chronic apical periodontitis between non-HIV-infected patients and HIV-infected patients undergoing HAART. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Local Delivery of the Toll-Like Receptor 9 Ligand CpG Downregulates Host Immune and Inflammatory Responses, Ameliorating Established Leishmania (Viannia) panamensis Chronic Infection

PubMed Central

Fernández, Olga L.; Rodriguez-Pinto, Daniel; Castilho, Tiago M.; Corral Caridad, Maria J.; Goldsmith-Pestana, Karen; Saravia, Nancy Gore; McMahon-Pratt, Diane

2017-01-01

ABSTRACT Infection by Leishmania (Viannia) panamensis, the predominant etiologic agent for cutaneous leishmaniasis in Colombia, is characterized by a chronic mixed inflammatory response. Current treatment options are plagued by toxicity, lengthy treatment regimens, and growing evidence of drug resistance. Immunotherapy, modulating the immune system to mount a protective response, may provide an alternate therapeutic approach. We investigated the ability of the Toll-like receptor 9 (TLR9) ligand CpG to modulate established disease in the L. (V.) panamensis mouse model. Treatment of established infection with a high dose (50 μg) of CpG ameliorated disease and lowered parasite burden. Interestingly, immediately after treatment there was a significant increase in transforming growth factor β (TGF-β) and concomitantly an increase in T regulatory cell (Treg) function. Although a general reduction in cell-mediated immune cytokine and chemokine (gamma interferon [IFN-γ], interleukin 10 [IL-10], IL-13, IL-6, granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-4, and MIP-1α) responses of the treated mice was observed, certain chemokines (RANTES, monocyte chemoattractant protein 1[MCP-1], and IP-10) were increased. Further, in peripheral blood mononuclear cells (PBMCs) from patients with cutaneous leishmaniasis, CpG treatment similarly exhibited a dose-response effect on the production of IFN-γ, IL-17, IL-10, and IL-13, with reductions observed at higher doses. To further understand the underlying mechanisms and cell populations driving the CpG mediated response, we examined the ex vivo dose effects mediated by the TLR9+ cell populations (dendritic cells, macrophages, and B cells) found to accumulate labeled CpG in vivo. Notably, B cells altered the production of IL-17, IL-13, and IFN-γ, supporting a role for B cells functioning as antigen-presenting cells (APCs) and/or regulatory cells during infection. Interestingly, B cells have been previously

Chronic hepatitis C infection and liver disease in HIV co-infected patients in Asia

PubMed Central

Durier, Nicolas; Yunihastuti, Evy; Ruxrungtham, Kiat; Van Kinh, Nguyen; Kamarulzaman, Adeeba; Boettiger, David; Widhani, Alvina; Avihingsanon, Anchalee; Huy, Bui Vu; Omar, Sharifah Faridah binti Syed; Sanityoso, Andri; Chittmittrapap, Salyavit; Dung, Nguyen Thi Hoai; Pillai, Veena; Suwan-Ampai, Tuangporn; Law, Matthew; Sohn, Annette H.; Matthews, Gail

2016-01-01

Data on markers of hepatitis C virus (HCV) disease in HIV-HCV co-infected patients in resource-limited settings are scarce. We assessed HCV-RNA, HCV genotype (GT), IL28B GT, and liver fibrosis (FibroScan®) in 480 HIV-infected patients with positive HCV antibody in four HIV treatment centers in South East Asia. We enrolled 165 (34.4%) patients in Jakarta, 158 (32.9%) in Bangkok, 110 (22.9%) in Hanoi, and 47 (9.8%) in Kuala Lumpur. Overall, 426 (88.8%) were male, the median (IQR) age was 38.1 (34.7–42.5) years, 365 (76.0%) reported HCV exposure through injecting drug use, and 453 (94.4%) were on combination antiretroviral therapy. The median (IQR) CD4 count was 446 (325–614) cells/mm3 and 208 (94.1%) of 221 patients tested had HIV-1 RNA <400 copies/ml. A total of 412 (85.8%) had detectable HCV-RNA, at a median (IQR) of 6.2 (5.4-6.6) log10 IU/mL. Among 380 patients with HCV GT, 223 (58.7%) had GT1, 97 (25.5%) had GT3, 43 (11.3%) had GT6, 8 (2.1%) had GT4, 2 (0.5%) had GT2, and 7 (1.8%) had indeterminate GT. Of 222 patients with IL28B testing, 189 (85.1%) had rs12979860 CC genotype, and 199 (89.6%) had rs8099917 TT genotype. Of 380 patients with FibroScan®, 143 (37.6%) had no/mild liver fibrosis (F0-F1), 83 (21.8%) had moderate fibrosis (F2), 74 (19.5%) had severe fibrosis (F3), and 79 (20.8%) had cirrhosis (F4). One patient (0.3%) had FibroScan® failure. A high proportion of HIV-HCV co-infected patients had chronic HCV infection. HCV GT1 was predominant, and 62% of patients had liver disease warranting prompt treatment (>=F2). PMID:27917597

Increased B7-H1 expression on dendritic cells correlates with programmed death 1 expression on T cells in simian immunodeficiency virus-infected macaques and may contribute to T cell dysfunction and disease progression.

PubMed

Xu, Huanbin; Wang, Xiaolei; Pahar, Bapi; Moroney-Rasmussen, Terri; Alvarez, Xavier; Lackner, Andrew A; Veazey, Ronald S

2010-12-15

Suppression of dendritic cell (DC) function in HIV-1 infection is thought to contribute to inhibition of immune responses and disease progression, but the mechanism of this suppression remains undetermined. Using the rhesus macaque model, we show B7-H1 (programmed death [PD]-L1) is expressed on lymphoid and mucosal DCs (both myeloid DCs and plasmacytoid DCs), and its expression significantly increases after SIV infection. Meanwhile, its receptor, PD-1, is upregulated on T cells in both peripheral and mucosal tissues and maintained at high levels on SIV-specific CD8(+) T cell clones in chronic infection. However, both B7-H1 and PD-1 expression in SIV controllers was similar to that of controls. Expression of B7-H1 on both peripheral myeloid DCs and plasmacytoid DCs positively correlated with levels of PD-1 on circulating CD4(+) and CD8(+) T cells, viremia, and declining peripheral CD4(+) T cell levels in SIV-infected macaques. Importantly, blocking DC B7-H1 interaction with PD-1(+) T cells could restore SIV-specific CD4(+) and CD8(+) T cell function as evidenced by increased cytokine secretion and proliferative capacity. Combined, the results indicate that interaction of B7-H1-PD-1 between APCs and T cells correlates with impairment of CD4(+) Th cells and CTL responses in vivo, and all are associated with disease progression in SIV infection. Blockade of this pathway may have therapeutic implications for HIV-infected patients.