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Critical Requirement of GABP? for Normal T Cell Development*  

PubMed Central

GA binding protein (GABP) consists of GABP? and GABP? subunits. GABP? is a member of Ets family transcription factors and binds DNA via its conserved Ets domain, whereas GABP? does not bind DNA but possesses transactivation activity. In T cells, GABP has been demonstrated to regulate the gene expression of interleukin-7 receptor ? chain (IL-7R?) and postulated to be critical in T cell development. To directly investigate its function in early thymocyte development, we used GABP? conditional knock-out mice where the exons encoding the Ets DNA-binding domain are flanked with LoxP sites. Ablation of GABP? with the Lck-Cre transgene greatly diminished thymic cellularity, blocked thymocyte development at the double negative 3 (DN3) stage, and resulted in reduced expression of T cell receptor (TCR) ? chain in DN4 thymocytes. By chromatin immunoprecipitation, we demonstrated in DN thymocytes that GABP? is associated with transcription initiation sites of genes encoding key molecules in TCR rearrangements. Among these GABP-associated genes, knockdown of GABP? expression by RNA interference diminished expression of DNA ligase IV, Artemis, and Ku80 components in DNA-dependent protein kinase complex. Interestingly, forced expression of prearranged TCR but not IL-7R? can alleviate the DN3 block in GABP?-targeted mice. Our observations collectively indicate that in addition to regulating IL-7R? expression, GABP is critically required for TCR rearrangements and hence normal T cell development. PMID:20139079

Yu, Shuyang; Zhao, Dong-Mei; Jothi, Raja; Xue, Hai-Hui



Gadd45? Is Dispensable for Normal Mouse Development and T-Cell Proliferation  

PubMed Central

Gadd45?, a family member of the growth arrest and DNA damage-inducible gene family 45 (Gadd45), is strongly induced by interleukin-2 (IL-2) in peripheral T cells. While in most tissues all Gadd45 family members are expressed, Gadd45? is the only member that is induced by IL-2. Here we show that the IL-2-induced expression of Gadd45? is dependent on a signaling pathway mediated by the tyrosine kinase Jak3 and the transcription factors Stat5a and Stat5b (signal transducer and activator of transcription). Previous studies with ectopically overexpressed Gadd45? in various cell lines implicated its function in negative growth control. To analyze the physiological role of Gadd45? we used homologous recombination to generate mice lacking Gadd45?. Gadd45?-deficient mice develop normally, are indistinguishable from their littermates, and are fertile. Furthermore, hematopoiesis in mice lacking Gadd45? is not impaired and Gadd45?-deficient T lymphocytes show normal responses to IL-2. These data demonstrate that Gadd45? is not essential for normal mouse development and hematopoiesis, possibly due to functional redundancy among the Gadd45 family members. Gadd45? is also dispensable for IL-2-induced T-cell proliferation. PMID:11287618

Hoffmeyer, Angelika; Piekorz, Roland; Moriggl, Richard; Ihle, James N.



T Cells Development Is Different between Thymus from Normal and Intrauterine Growth Restricted Pig Fetus at Different Gestational Stage  

PubMed Central

This experiment was conducted to evaluate the development of T cells in intrauterine growth retarded (IUGR) piglets at different gestational stages, and tentatively explore the relationship between T cells development and the Notch signaling pathway. A total of 18 crossbred (Landrace×Large white) primiparous sows were mated at similar weights and estruses and euthanized at d 60, 90 and 110 of gestation with six replicates for each time point. One IUGR and one normal fetus were picked from each litter. The T-cell subsets, mRNA expression of Delta-like1, Delta-like4, Jagged1, and Notch2 genes in the thymus were investigated. Compared to normal piglets, CD3+CD4?CD8+ cells in IUGR fetuses at d 90 was 0.13% lower (p<0.05). At d 110 of gestation CD8+ T cells in IUGR fetuses was 0.19% lower (p<0.05). The percentage of CD8+ T cells was 3.14% lower (p<0.05) of the total T cells in IUGR pigs at d 60. The abundance of Notch2 and Delta-like4 mRNA at d 110 was 20.93% higher and 0.77% (p<0.05) lower, and Delta-like1 mRNA at d 90 was 0.19% (p<0.05) higher compared to normal pigs. These results suggested that normal fetuses had a greater proportion of T-cell subsets at earlier gestation periods, and the Notch signaling pathway was likely partially responsible for these differences to some degree. PMID:25049796

Lin, Yan; Wang, Junjun; Wang, Xiaoqiu; Wu, Weizong; Lai, Changhua



Cell adhesion molecules involved in intrathymic T cell development.  


During stem cell migration to the thymus, intrathymic maturation of T cells, and emigration of mature T cells out of the thymus, intercellular interactions of developing T cells with a myriad of cell types are required for normal T cell development. Intercellular interactions of T cell precursors with endothelial cells, thymic epithelial cells, fibroblasts, thymic macrophages and dendritic cells are all mediated by adhesion molecules on immature T cells binding to ligands on thymic microenvironment cells. While many receptor-ligand interactions that are important in intrathymic T cell development are known, the adhesion molecules that are important for migration of T cell precursors to the thymus and for emigration of mature thymocytes from the thymus are poorly understood. An emerging concept is that select adhesion molecules at discrete stages of T cell maturation participate in and regulate the complex processes of T cell development. PMID:7693023

Patel, D D; Haynes, B F



Activated ?? T Cells Promote the Activation of Uveitogenic T Cells and Exacerbate EAU Development  

PubMed Central

Purpose. To determine how the activation of ?? T cells affects the generation of uveitogenic ?? T cells and the development of experimental autoimmune uveitis (EAU). Methods. ?? T cells were isolated from B6 mice immunized with the uveitogenic peptide IRBP1–20 and ?? T cells from immunized TCR-??/? mice. Resting ?? T cells were prepared by culture of separated ?? T cells in cytokine-free medium for 3 to 5 days, when they showed downregulation of CD69 expression. Activated ?? T cells were prepared by incubating resting ?? T cells with anti-?? TCR (GL3) for 2 days. Responder ?? T cells were cocultured with immunizing antigen and antigen-presenting cells. The numbers of antigen-specific T cells expressing IL-17 or IFN-? were determined by intracellular staining followed by FACS analysis after stimulation, with or without the addition of purified ?? T cells. The cytokines in the culture medium were measured by ELISA. Results. Highly enriched ?? T cells exert widely different effects on autoreactive ?? T cells in EAU, depending on the activation status of the ?? T cells. Whereas nonactivated ?? T cells had little effect on the activation of interphotoreceptor retinoid-binding protein–specific ?? T cells in vitro and in vivo, activated ?? T cells promoted the generation of uveitogenic T cells and exacerbated the development of EAU. Conclusions. The functional ability of ?? T cells is greatly influenced by their activation status. Activated ?? T cells exacerbate EAU through increased activation of uveitogenic T cells. PMID:21296823

Nian, Hong; Shao, Hui; O'Brien, Rebecca L.; Born, Willi K.; Kaplan, Henry J.



The neurotransmitter glutamate and human T cells: glutamate receptors and glutamate-induced direct and potent effects on normal human T cells, cancerous human leukemia and lymphoma T cells, and autoimmune human T cells.  


Glutamate is the most important excitatory neurotransmitter of the nervous system, critically needed for the brain's development and function. Glutamate has also a signaling role in peripheral organs. Herein, we discuss glutamate receptors (GluRs) and glutamate-induced direct effects on human T cells. T cells are the most important cells of the adaptive immune system, crucially needed for eradication of all infectious organisms and cancer. Normal, cancer and autoimmune human T cells express functional ionotropic and metabotropic GluRs. Different GluR subtypes are expressed in different T cell subtypes, and in resting vs. activated T cells. Glutamate by itself, at low physiological 10(-8)M to 10(-5)M concentrations and via its several types of GluRs, activates many key T cell functions in normal human T cells, among them adhesion, migration, proliferation, intracellular Ca(2+) fluxes, outward K(+) currents and more. Glutamate also protects activated T cells from antigen-induced apoptotic cell death. By doing all that, glutamate can improve substantially the function and survival of resting and activated human T cells. Yet, glutamate's direct effects on T cells depend dramatically on its concentration and might be inhibitory at excess pathological 10(-3)M glutamate concentrations. The effects of glutamate on T cells also depend on the specific GluRs types expressed on the target T cells, the T cell's type and subtype, the T cell's resting or activated state, and the presence or absence of other simultaneous stimuli besides glutamate. Glutamate also seems to play an active role in T cell diseases. For example, glutamate at several concentrations induces or enhances significantly very important functions of human T-leukemia and T-lymphoma cells, among them adhesion to the extracellular matrix, migration, in vivo engraftment into solid organs, and the production and secretion of the cancer-associated matrix metalloproteinase MMP-9 and its inducer CD147. Glutamate induces all these effects via activation of GluRs highly expressed in human T-leukemia and T-lymphoma cells. Glutamate also affects T cell-mediated autoimmune diseases. With regards to multiple sclerosis (MS), GluR3 is highly expressed in T cells of MS patients, and upregulated significantly during relapse and when there is neurological evidence of disease activity. Moreover, glutamate or AMPA (10(-8)M to 10(-5)M) enhances the proliferation of autoreactive T cells of MS patients in response to myelin proteins. Thus, glutamate may play an active role in MS. Glutamate and its receptors also seem to be involved in autoimmune rheumatoid arthritis and systemic lupus erythematosus. Finally, T cells can produce and release glutamate that in turn affects other cells, and during the contact between T cells and dendritic cells, the latter cells release glutamate that has potent effects on the T cells. Together, these evidences show that glutamate has very potent effects on normal, and also on cancer and autoimmune pathological T cells. Moreover, these evidences suggest that glutamate and glutamate-receptor agonists might be used for inducing and boosting beneficial T cell functions, for example, T cell activity against cancer and infectious organisms, and that glutamate-receptor antagonists might be used for preventing glutamate-induced activating effects on detrimental autoimmune and cancerous T cells. PMID:24584970

Ganor, Yonatan; Levite, Mia



Normal Immune Development and Glucocorticoid-Induced Thymocyte Apoptosis in Mice Deficient for the T-Cell Death-Associated Gene 8 Receptor  

PubMed Central

T-cell death-associated gene 8 (TDAG8) is a G-protein-coupled receptor transcriptionally upregulated by glucocorticoids (GCs) and implicated by overexpression studies in psychosine-mediated inhibition of cytokinesis and in GC-induced apoptosis. To examine the physiological function of TDAG8, we generated knockout (KO) mice by homologous recombination. An enhanced green fluorescent protein reporter was knocked into the disrupted tdag8 locus to allow the analysis of TDAG8 expression in living cells. Interestingly, we found that during thymocyte development, TDAG8 expression resembled the dynamic regulation described for known modulators of GC-induced apoptosis, including Bcl-2, Notch1, and GC receptor. TDAG8 was expressed in double-negative cells, was downregulated at the double-positive transition, and was upregulated in single-positive thymocytes. However, despite this striking expression pattern, maturation and selection of thymocytes, as well as major immune functions, were not affected in TDAG8 KO mice. In contrast to previous overexpression results, TDAG8 was dispensable for psychosine-induced formation of multinucleated cells. Furthermore, TDAG8 KO thymocytes showed normal apoptosis following in vivo and in vitro GC treatment. These results, while establishing a useful reporter strain to study T-lymphocyte maturation, argue against a critical role for TDAG8 in immune development, psychosine-mediated inhibition of cytokinesis, and GC-induced cell death. PMID:16382156

Radu, Caius G.; Cheng, Donghui; Nijagal, Amar; Riedinger, Mireille; McLaughlin, Jami; Yang, Li V.; Johnson, James; Witte, Owen N.



Linked T Cell Receptor and Cytokine Signaling Govern the Development of the Regulatory T cell Repertoire  

PubMed Central

Summary Appropriate development of regulatory T cells (Tregs) is necessary to prevent autoimmunity. Neonatal mice, unlike adults, lack factors required for Treg development. It is unclear what these missing factors are. However, signals emanating from the TCR, CD28 and ?c-dependent cytokine receptors are required for Treg development. Herein we demonstrate that expression of a constitutively-active STAT5b transgene (STAT5b-CA) allows for Treg development in neonatal mice and restores Treg numbers in CD28?/? mice. Sequence analysis of TCR genes in STAT5b-CA Tregs indicates that ectopic STAT5 activation results in a TCR repertoire that more closely resembles that of naïve T cells. Using MHCII tetramers to identify antigen-specific T cells, we demonstrate that STAT5 signals divert thymocytes normally destined to become naïve T cells into the Treg lineage. Our data support a two-step model of Treg differentiation in which TCR/CD28 signals induce cytokine responsiveness; STAT5-inducing cytokines then complete the program of Treg differentiation. PMID:18199418

Burchill, Matthew A.; Yang, Jianying; Vang, Kieng B.; Moon, James J.; Chu, H. Hamlet; Lio, Chan-Wang J.; Vegoe, Amanda L.; Hsieh, Chyi-Song; Jenkins, Marc K.; Farrar, Michael A.



T Cell Recruitment in the Brain during Normal Aging.  


Aging-related changes in the peripheral immune response are well documented, but less is known about changes of the immune response in the central nervous system. Reactivity of microglia, effectors of the brain innate immunity, is known to increase in the aged brain, but little attention has been hitherto devoted to T cell recruitment. Data in rodents point to a gradual enhancement of T cell homing to the brain in the steady state since the middle age. Experimental findings also point to enhanced transmigration of lymphocytes as part of an amplified response of the aging brain to acute exogenous inflammatory insults. Thus, available data support the capacity of the aged brain to mount a robust immune response, in contrast with peripheral immunity decline, and indicate that such central response involves recruitment of lymphocytes. These findings open many questions, including blood-brain barrier molecular regulation and infiltrated T cell subtypes during normal aging. The crosstalk between T cells, glia, and neurons also remains to be clarified in the aged brain parenchyma. This intercellular dialogue and related signaling could be relevant for both protection of the aged brain and its vulnerability to neurological disease. PMID:23049498

Gemechu, Jickssa M; Bentivoglio, Marina



T Cell Recruitment in the Brain during Normal Aging  

PubMed Central

Aging-related changes in the peripheral immune response are well documented, but less is known about changes of the immune response in the central nervous system. Reactivity of microglia, effectors of the brain innate immunity, is known to increase in the aged brain, but little attention has been hitherto devoted to T cell recruitment. Data in rodents point to a gradual enhancement of T cell homing to the brain in the steady state since the middle age. Experimental findings also point to enhanced transmigration of lymphocytes as part of an amplified response of the aging brain to acute exogenous inflammatory insults. Thus, available data support the capacity of the aged brain to mount a robust immune response, in contrast with peripheral immunity decline, and indicate that such central response involves recruitment of lymphocytes. These findings open many questions, including blood-brain barrier molecular regulation and infiltrated T cell subtypes during normal aging. The crosstalk between T cells, glia, and neurons also remains to be clarified in the aged brain parenchyma. This intercellular dialogue and related signaling could be relevant for both protection of the aged brain and its vulnerability to neurological disease. PMID:23049498

Gemechu, Jickssa M.; Bentivoglio, Marina



Development of promyelocytic leukemia zinc finger-expressing innate CD4 T cells requires stronger T-cell receptor signals than conventional CD4 T cells  

PubMed Central

MHC class II-expressing thymocytes and thymic epithelial cells can mediate CD4 T-cell selection resulting in functionally distinct thymocyte-selected CD4 (T-CD4) and epithelial-selected CD4 (E-CD4) T cells, respectively. However, little is known about how T-cell receptor (TCR) signaling influences the development of these two CD4 T-cell subsets. To study TCR signaling for T-CD4 T-cell development, we used a GFP reporter system of Nur77 in which GFP intensity directly correlates with TCR signaling strength. T-CD4 T cells expressed higher levels of GFP than E-CD4 T cells, suggesting that T-CD4 T cells received stronger TCR signaling than E-CD4 T cells during selection. Elimination of Ras GTPase-activating protein enhanced E-CD4 but decreased T-CD4 T-cell selection efficiency, suggesting a shift to negative selection. Conversely, the absence of IL-2–inducible T-cell kinase that causes poor E-CD4 T-cell selection due to insufficient TCR signaling improved T-CD4 T-cell generation, consistent with rescue from negative selection. Strong TCR signaling during T-CD4 T-cell development correlates with the expression of the transcription factor promyelocytic leukemia zinc finger protein. However, although modulation of the signaling strength affected the efficiency of T-CD4 T-cell development during positive and negative selection, the signaling strength is not as important for the effector function of T-CD4 T cells. These findings indicate that innate T-CD4 T cells, together with invariant natural killer T cells and ?? T cells, receive strong TCR signals during their development and that signaling requirements for the development and the effector functions are distinct. PMID:22988097

Qiao, Yu; Zhu, Lingqiao; Sofi, Hanief; Lapinski, Philip E.; Horai, Reiko; Mueller, Kristen; Stritesky, Gretta L.; He, Xi; Teh, Hung-Sia; Wiest, David L.; Kappes, Dietmar J.; King, Philip D.; Hogquist, Kristin A.; Schwartzberg, Pamela L.; Sant’Angelo, Derek B.; Chang, Cheong-Hee



Conformational changes in the T cell receptor differentially determine T cell subset development in mice.  


In the thymus, immature T cells differentiate from common precursors to become T cells expressing either the ?? or ?? T cell receptor (TCR) complex. The CD3? subunit of the TCR complex is thought to transduce ligand-induced conformational changes in the TCR by recruiting the cytosolic adaptor protein Nck. To investigate the role of conformational changes in the TCR in T cell development, we generated mice with a germline mutation (C80G) in the extracellular domain of CD3?, which prevents the outside-in transmission of conformational changes in the TCR. The development of ?? T cells in the C80G mice was blocked at an early stage that depends on signaling by a precursor form of the TCR. In contrast, the C80G mutation did not impair the development of some subsets of ?? T cells, including V?1.1(+) cells; however, development of other ?? T cell subsets was blocked. A similar phenotype was observed in mice with a mutation in the cytoplasmic proline-rich sequence (PRS) of CD3?, the binding site for Nck. In a genetic complementation test, the PRS CD3? mutant failed to rescue the wild-type phenotype when expressed in heterozygosity with the C80G mutant. These data suggest that Nck may function as an effector of TCR conformational changes during T cell development. Additional experiments showed differential effects of the C80G mutation on the activation of TCR-dependent signaling pathways, which suggests that there are pathways that are either dependent on or independent of the transmission of conformational change in the receptor. PMID:25468995

Blanco, Raquel; Borroto, Aldo; Schamel, Wolfgang; Pereira, Pablo; Alarcon, Balbino



ShcA Regulates Late Stages of T Cell Development and Peripheral CD4+ T Cell Numbers.  


T cell development in the thymus is a highly regulated process that critically depends upon productive signaling via the preTCR at the ?-selection stage, as well as via the TCR for selection from the CD4(+)CD8(+) double-positive stage to the CD4 or CD8 single-positive stage. ShcA is an adapter protein expressed in thymocytes, and it is required for productive signaling through the preTCR, with impaired signaling via ShcA leading to a developmental block at the ?-selection checkpoint. However, the role of ShcA in subsequent stages of T cell development has not been addressed. In this study, we generated transgenic mice (CD4-Cre/ShcFFF mice) that specifically express a phosphorylation-defective dominant-negative ShcA mutant (ShcFFF) in late T cell development. Thymocytes in CD4-Cre/ShcFFF mice progressed normally through the ?-selection checkpoint, but displayed a significant reduction in the numbers of single-positive CD4(+) and CD8(+) thymocytes. Furthermore, CD4-Cre/ShcFFF mice, when bred with transgenic TCR mouse strains, had impaired signaling through the transgenic TCRs. Consistent with defective progression to the single-positive stage, CD4-Cre/ShcFFF mice also had significant peripheral lymphopenia. Moreover, these CD4-Cre/ShcFFF mice develop attenuated disease in CD4(+) T cell-dependent experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. Collectively, these data identify an important role for the adapter protein ShcA in later stages of thymic T cell development and in peripheral T cell-dependent events. PMID:25595778

Buckley, Monica W; Trampont, Paul C; Arandjelovic, Sanja; Fond, Aaron M; Juncadella, Ignacio J; Ravichandran, Kodi S



The role of ICOS in the development of CD4 T cell help and the reactivation of memory T cells  

E-print Network

The role of ICOS in the development of CD4 T cell help and the reactivation of memory T cells Simmi, Spain 3 Institute of Stem Cell Research, University of Edinburgh, King's Buildings, Edinburgh, UK We have addressed the role of the inducible costimulator (ICOS) in the development of T cell help for B

Maizels, Rick


Studies on the syngeneic mixed lymphocyte reaction. III. Development of a monoclonal antibody with specificity for autoreactive T cells  

PubMed Central

Monoclonal antibodies with specificity for autoreactive murine T cells have been developed. These antibodies inhibit proliferative response of splenic T cells activated by syngeneic spleen cells. These antibodies have no effect on the proliferative response of T cells activated by allogeneic spleen cells or PHA. The number of splenic T cells that react with these monoclonal antibodies is comparable in several normal mouse strains. PMID:6225824



Distinct p21 requirements for regulating normal and self-reactive T cells through IFN-? production.  


Self/non-self discrimination characterizes immunity and allows responses against pathogens but not self-antigens. Understanding the principles that govern this process is essential for designing autoimmunity treatments. p21 is thought to attenuate autoreactivity by limiting T cell expansion. Here, we provide direct evidence for a p21 role in controlling autoimmune T cell autoreactivity without affecting normal T cell responses. We studied C57BL/6, C57BL/6/lpr and MRL/lpr mice overexpressing p21 in T cells, and showed reduced autoreactivity and lymphadenopathy in C57BL/6/lpr, and reduced mortality in MRL/lpr mice. p21 inhibited effector/memory CD4(+) CD8(+) and CD4(-)CD8(-) lpr T cell accumulation without altering defective lpr apoptosis. This was mediated by a previously non-described p21 function in limiting T cell overactivation and overproduction of IFN-?, a key lupus cytokine. p21 did not affect normal T cell responses, revealing differential p21 requirements for autoreactive and normal T cell activity regulation. The underlying concept of these findings suggests potential treatments for lupus and autoimmune lymphoproliferative syndrome, without compromising normal immunity. PMID:25573673

Daszkiewicz, Lidia; Vázquez-Mateo, Cristina; Rackov, Gorjana; Ballesteros-Tato, André; Weber, Kathrin; Madrigal-Avilés, Adrián; Di Pilato, Mauro; Fotedar, Arun; Fotedar, Rati; Flores, Juana M; Esteban, Mariano; Martínez-A, Carlos; Balomenos, Dimitrios



Agonist-selected T cell development requires strong T cell receptor signaling and store-operated calcium entry.  


T cell receptor (TCR) signaling driven by interaction of the TCR with specific complexes of self-peptide and the major histocompatibility complex determines T cell fate in thymic development. However, the signaling pathway through which TCR signal strength regulates distinct T cell lineages remains unknown. Here we have used mice lacking the endoplasmic reticulum Ca2+ sensors stromal interaction molecule 1 (STIM1) and STIM2 to show that STIM-induced store-operated Ca2+ entry is not essential for thymic development of conventional TCR??+ T cells but is specifically required for the development of agonist-selected T cells (regulatory T cells, invariant natural killer T cells, and TCR??+ CD8??+ intestinal intraepithelial lymphocytes). The severe impairment of agonist-selected T cell development is mainly due to a defect in interleukin-2 (IL-2) or IL-15 signaling. Thus, STIM1 and STIM2-mediated store-operated Ca2+ influx, leading to efficient activation of NFAT (nuclear factor of activated T cells), is critical for the postselection maturation of agonist-selected T cells. PMID:23499491

Oh-Hora, Masatsugu; Komatsu, Noriko; Pishyareh, Mojgan; Feske, Stefan; Hori, Shohei; Taniguchi, Masaru; Rao, Anjana; Takayanagi, Hiroshi



Impaired NK1 + T Cell Development and Early IL4 Production in CD1Deficient Mice  

Microsoft Academic Search

The MHC class Ib molecule, CD1, has been conserved throughout mammalian evolution. To assess the function of CD1 in lymphocyte development, we generated mice with targeted disruption of the CD1.1 and CD1.2 genes. CD1-deficient mice have normal numbers of CD4+ and CD8+ T cells but marked reduction in NK1.1-bearing T cells, particularly those with a canonical gene rearrangement of V?14-J?281.

Yi-Hua Chen; Nancy M Chiu; Manas Mandal; Ning Wang; Chyung-Ru Wang



Essential Role of Survivin, an Inhibitor of Apoptosis Protein, in T Cell Development, Maturation, and Homeostasis  

PubMed Central

Survivin is an inhibitor of apoptosis protein that also functions during mitosis. It is expressed in all common tumors and tissues with proliferating cells, including thymus. To examine its role in apoptosis and proliferation, we generated two T cell–specific survivin-deficient mouse lines with deletion occurring at different developmental stages. Analysis of early deleting survivin mice showed arrest at the pre–T cell receptor proliferating checkpoint. Loss of survivin at a later stage resulted in normal thymic development, but peripheral T cells were immature and significantly reduced in number. In contrast to in vitro studies, loss of survivin does not lead to increased apoptosis. However, newborn thymocyte homeostatic and mitogen-induced proliferation of survivin-deficient T cells were greatly impaired. These data suggest that survivin is not essential for T cell apoptosis but is crucial for T cell maturation and proliferation, and survivin-mediated homeostatic expansion is an important physiological process of T cell development. PMID:14699085

Xing, Zheng; Conway, Edward M.; Kang, Chulho; Winoto, Astar



T Cell Development in Mice Lacking All T Cell Receptor z Family Members ( z , h , and Fc e RI g )  

Microsoft Academic Search

Summary The z family includes z , h , and Fc e RI g (Fc g ). Dimers of the z family proteins function as sig- nal transducing subunits of the T cell antigen receptor (TCR), the pre-TCR, and a subset of Fc receptors. In mice lacking z \\/ h chains, T cell development is impaired, yet low numbers of

Elizabeth W. Shores; Masao Ono; Tsutomo Kawabe; Connie L. Sommers; Tom Tran; Kin Lui; Mark C. Udey; Jeffrey Ravetch; Paul E. Love


Preferential recognition of self antigens despite normal thymic deletion of CD4(+)CD25(+) regulatory T cells.  


T cell tolerance to self Ags is in part established in the thymus by induction of apoptosis or anergy of potentially autoreactive thymocytes. Some autospecific T cells nevertheless migrate to peripheral lymphoid organs but are kept under control by the recently identified CD4(+)CD25(+) regulatory T cell subset. Because these cells inhibit autoimmunity more efficiently than useful non-self Ag-specific immune responses, they are probably autospecific, posing important questions as to how they develop in the thymus. In this study we show that significantly more peripheral CD4(+)CD25(+) regulatory T cells recognize self than non-self Ags. However, we also show for a large panel of endogenous superantigens as well as for self peptide/MHC complexes that autospecific CD4(+)CD25(+) thymocyte precursors are normally deleted during ontogeny. Combined, our data firmly establish that the repertoire of regulatory T cells is specifically enriched in autospecific cells despite the fact that their precursors are normally susceptible to thymic deletion. PMID:11823492

Romagnoli, Paola; Hudrisier, Denis; van Meerwijk, Joost P M



Function of the nucleotide exchange activity of vav1 in T cell development and activation.  


The guanine nucleotide exchange factor (GEF) Vav1 is essential for transducing T cell antigen receptor (TCR) signals and therefore plays a critical role in the development and activation of T cells. It has been presumed that the GEF activity of Vav1 is important for its function; however, there has been no direct demonstration of this. Here, we generated mice expressing enzymatically inactive, but normally folded, Vav1 protein. Analysis of these mice showed that the GEF activity of Vav1 was necessary for the selection of thymocytes and for the optimal activation of T cells, including signal transduction to Rac1, Akt, and integrins. In contrast, the GEF activity of Vav1 was not required for TCR-induced calcium flux, activation of extracellular signal-regulated kinase and protein kinase D1, and cell polarization. Thus, in T cells, the GEF activity of Vav1 is essential for some, but not all, of its functions. PMID:20009105

Saveliev, Alexander; Vanes, Lesley; Ksionda, Olga; Rapley, Jonathan; Smerdon, Stephen J; Rittinger, Katrin; Tybulewicz, Victor L J



Function of the Nucleotide Exchange Activity of Vav1 in T cell Development and Activation*  

PubMed Central

The guanine nucleotide exchange factor (GEF) Vav1 is essential for transducing T cell antigen receptor (TCR) signals and therefore plays a critical role in the development and activation of T cells. It has been presumed that the GEF activity of Vav1 is important for its function; however, there has been no direct demonstration of this. Here, we generated mice expressing enzymatically inactive, but normally folded, Vav1 protein. Analysis of these mice showed that the GEF activity of Vav1 was necessary for the selection of thymocytes and for the optimal activation of T cells, including signal transduction to Rac1, Akt, and integrins. In contrast, the GEF activity of Vav1 was not required for TCR-induced calcium flux, activation of extracellular signal–regulated kinase (ERK) and protein kinase D1 (PKD1), and cell polarization. Thus, in T cells, the GEF activity of Vav1 is essential for some, but not all, of its functions. PMID:20009105

Saveliev, Alexander; Vanes, Lesley; Ksionda, Olga; Rapley, Jonathan; Smerdon, Stephen J.; Rittinger, Katrin; Tybulewicz, Victor L. J.



Fractionation of normal and leukemic T-cells by lectin-affinity column chromatography.  


A method for rapid fractionation of normal and leukemic T-cells (Jurkat, RPMI-8402, MOLT-4), using lectin-affinity column chromatography, is described. CNBr-activated Sepharose 6MB was used as a non-mobile phase. The gel was covalently conjugated with Dolichos biflorus agglutinin (DBA) over 24 h. The normal cells were eluted by phosphate buffered saline (Ca(2+) and Mg(2+) free), while the leukemic T-cells, interacting with DBA, were removed by N-acetyl-D-galactosamine or by low-concentrated acetic acid as a mobile phase. The cell fractions were detected spectrophotometrically at 600 nm. The rate of cell elution decreased in the order: normal>leukemic T-cells. The viability and the type of separated T-cell fractions were characterized by flow cytometry, using adequate fluorescent antibodies. The interactions between leukemic T-cells and DBA-saturated Sepharose beads were examined by fluorescent microscopy, using fluorescent isothiocyanate-DBA as a fluorescent marker. PMID:12127693

Ohba, H; Bakalova, R; Moriwaki, S; Nakamura, O



Feedback Regulation of T Cell Development in the Thymus  

Microsoft Academic Search

Recent findings suggest that mature T cells in the thymus may regulate the growth and differentiation of immature thymocytes. Here we use mathematical modeling and computer simulations to identify the thymocyte subsets that might serve as targets for regulation, and the processes that might be affected by regulation. our results suggest that thymocyte development is subject to regulation through two

Ramit Mehr; Alan S. Perelson; Masha Fridkis-Hareli; Amiela Globerson



Normal T-cell turnover in sooty mangabeys harboring active simian immunodeficiency virus infection.  


Sooty mangabeys naturally infected with simian immunodeficiency virus (SIV) remain healthy though they harbor viral loads comparable to those in rhesus macaques that progress to AIDS. To assess the immunologic basis of disease resistance in mangabeys, we compared the effect of SIV infection on T-cell regeneration in both monkey species. Measurement of the proliferation marker Ki-67 by flow cytometry showed that mangabeys harbored proliferating T cells at a level of 3 to 4% in peripheral blood irrespective of their infection status. In contrast, rhesus macaques demonstrated a naturally high fraction of proliferating T cells (7%) that increased two- to threefold following SIV infection. Ki-67(+) T cells were predominantly CD45RA(-), indicating increased proliferation of memory cells in macaques. Quantitation of an episomal DNA product of T-cell receptor alpha rearrangement (termed alpha1 circle) showed that the concentration of recent thymic emigrants in blood decreased with age over a 2-log unit range in both monkey species, consistent with age-related thymic involution. SIV infection caused a limited decrease of alpha1 circle numbers in mangabeys as well as in macaques. Dilution of alpha1 circles by T-cell proliferation likely contributed to this decrease, since alpha1 circle numbers and Ki-67(+) fractions correlated negatively. These findings are compatible with immune exhaustion mediated by abnormal T-cell proliferation, rather than with early thymic failure, in SIV-infected macaques. Normal T-cell turnover in SIV-infected mangabeys provides an explanation for the long-term maintenance of a functional immune system in these hosts. PMID:10627531

Chakrabarti, L A; Lewin, S R; Zhang, L; Gettie, A; Luckay, A; Martin, L N; Skulsky, E; Ho, D D; Cheng-Mayer, C; Marx, P A



T-Cell Receptor V_beta Expression in Normal Human Skin  

Microsoft Academic Search

The skin-associated immune system is the first line of defense against pathogenic attack from the environment and is simultaneously tolerant to localized autoantigens and to antigens of the normal microbial flora. The T-cell receptor (TCR) repertoire of skin lymphocytes may therefore be influenced by the skin microenvironment. We studied the expression of TCR beta-chain variable region (V_beta) genes in normal

David A. Dunn; Anne-Sophie Gadenne; Swarnalatha Simha; Ethan A. Lerner; Michael Bigby; Paul A. Bleicher



Normalizing glycosphingolipids restores function in CD4+ T cells from lupus patients.  


Patients with the autoimmune rheumatic disease systemic lupus erythematosus (SLE) have multiple defects in lymphocyte signaling and function that contribute to disease pathogenesis. Such defects could be attributed to alterations in metabolic processes, including abnormal control of lipid biosynthesis pathways. Here, we reveal that CD4+ T cells from SLE patients displayed an altered profile of lipid raft-associated glycosphingolipids (GSLs) compared with that of healthy controls. In particular, lactosylceramide, globotriaosylceramide (Gb3), and monosialotetrahexosylganglioside (GM1) levels were markedly increased. Elevated GSLs in SLE patients were associated with increased expression of liver X receptor ? (LXR?), a nuclear receptor that controls cellular lipid metabolism and trafficking and influences acquired immune responses. Stimulation of CD4+ T cells isolated from healthy donors with synthetic and endogenous LXR agonists promoted GSL expression, which was blocked by an LXR antagonist. Increased GSL expression in CD4+ T cells was associated with intracellular accumulation and accelerated trafficking of GSL, reminiscent of cells from patients with glycolipid storage diseases. Inhibition of GSL biosynthesis in vitro with a clinically approved inhibitor (N-butyldeoxynojirimycin) normalized GSL metabolism, corrected CD4+ T cell signaling and functional defects, and decreased anti-dsDNA antibody production by autologous B cells in SLE patients. Our data demonstrate that lipid metabolism defects contribute to SLE pathogenesis and suggest that targeting GSL biosynthesis restores T cell function in SLE. PMID:24463447

McDonald, Georgia; Deepak, Shantal; Miguel, Laura; Hall, Cleo J; Isenberg, David A; Magee, Anthony I; Butters, Terry; Jury, Elizabeth C



Essential Role of LAT in T Cell Development  

Microsoft Academic Search

The linker molecule LAT is a substrate of the tyrosine kinases activated following TCR engagement. Phosphorylated LAT binds many critical signaling molecules. The central role of this molecule in TCR-mediated signaling has been demonstrated by experiments in a LAT-deficient cell line. To probe the role of LAT in T cell development, the LAT gene was disrupted by targeting. LAT-deficient mice

Weiguo Zhang; Connie L Sommers; Deborah N Burshtyn; Christopher C Stebbins; Jan B DeJarnette; Ronald P Trible; Alexander Grinberg; Henry C Tsay; Helena M Jacobs; Craig M Kessler; Eric O Long; Paul E Love; Lawrence E Samelson



T-cell responses to neurofilament light protein are part of the normal immune repertoire.  


Multiple sclerosis (MS) is an inflammatory disease of the central nervous system in which axonal damage and degeneration contribute significantly to the progressive irreversible neurological disability. Similar to pathogenic myelin autoimmunity, autoimmune responses to neuronal antigens may contribute to axonal damage and irreversible disability in MS. Auto-antibodies to the axonal cytoskeletal protein neurofilament light (NF-L) are associated with cerebral atrophy in MS and we have recently reported that NF-L autoimmunity is pathogenic in mice. However, the T-cell response to NF-L in MS patients has not been examined. Here, we identify and characterize T-cell proliferative responses to NF-L as compared with myelin oligodendrocyte glycoprotein (MOG) in MS patients and healthy controls. Using a carboxyfluorescein succinimidyl ester dilution assay, we show that while responses to MOG are dominated by CD3(+)CD4(+) T cells, responses to NF-L were observed in both CD3(+)CD4(+) and CD3(+)CD8(+) T-cell populations. Both MOG- and NF-L-reactive cells expressed CD45RO(+), indicative of a memory phenotype. Moreover, in contrast to MOG stimulation which predominantly induced IFN-gamma, both T(h)1- and T(h)2-type T-cell responses to NF-L were observed as indicated by the induction of IFN-gamma, tumor necrosis factor-alpha as well as IL-4. The finding of T-cell responses to NF-L in MS patients may reflect transient activation of pathogenic potential but their presence also in healthy controls indicates that these cells are part of the normal immune repertoire. PMID:19240089

Huizinga, Ruth; Hintzen, Rogier Q; Assink, Karin; van Meurs, Marjan; Amor, Sandra



The Effects of TLR Activation on T-Cell Development and Differentiation  

PubMed Central

Invading pathogens have unique molecular signatures that are recognized by Toll-like receptors (TLRs) resulting in either activation of antigen-presenting cells (APCs) and/or costimulation of T cells inducing both innate and adaptive immunity. TLRs are also involved in T-cell development and can reprogram Treg cells to become helper cells. T cells consist of various subsets, that is, Th1, Th2, Th17, T follicular helper (Tfh), cytotoxic T lymphocytes (CTLs), regulatory T cells (Treg) and these originate from thymic progenitor thymocytes. T-cell receptor (TCR) activation in distinct T-cell subsets with different TLRs results in differing outcomes, for example, activation of TLR4 expressed in T cells promotes suppressive function of regulatory T cells (Treg), while activation of TLR6 expressed in T cells abrogates Treg function. The current state of knowledge of regarding TLR-mediated T-cell development and differentiation is reviewed. PMID:22737174

Jin, Bo; Sun, Tao; Yu, Xiao-Hong; Yang, Ying-Xiang; Yeo, Anthony E. T.



Differential requirement of RasGRP1 for ?? T cell development and activation  

PubMed Central

?? T cells (??T) belong to a distinct T cell lineage that performs immune functions different from ?? T cells (??T). Previous studies have established that Erk1/2 MAPKs are critical for positive selection of ??T cells. Additional evidence also suggests that elevated Erk1/2 activity promotes ??T cell generation. RasGRP1, a guanine nucleotide releasing factor for Ras, plays an important role in positive selection of ??T cells by activating the Ras-Erk1/2 pathway. In this report, we demonstrate that RasGRP1 is critical for TCR-induced Erk1/2 activation in ??T cells but exerts different roles for ??T cell generation and activation. Deficiency of RasGRP1 does not obviously affect ??T cell numbers in the thymus but leads to increased ??T cells, particularly CD4?CD8+ ??T cells, in the peripheral lymphoid organs. The virtually unhindered ??T cell development in the RasGRP1?/? thymus proved to be cell intrinsic, while the increase in CD8+ ??T cells is caused by non-cell-intrinsic mechanisms. Our data provides genetic evidence that decreased Erk1/2 activation in the absence of RasGRP1 is compatible for ??T cell generation. Although RasGRP1 is dispensable for ??T cell generation, RasGRP1-deficient ??T cells are defective in proliferation following TCR stimulation. Additionally, RasGRP1-deficient ??T cells are impaired to produce IL-17 but not IFN?. Together, these observations have revealed that RasGRP1 plays differential roles for ?? and ?? T cell development but is critical for ??T cell proliferation and production of IL-17. PMID:22623331

Chen, Yong; Ci, Xinxin; Gorentla, Balachandra; Sullivan, Sarah A.; Stone, James C.; Zhang, Weiguo; Pereira, Pablo; Lu, Jianxin; Zhong, Xiao-Ping



Essential role for Vav1 in activation, but not development, of gd T cells  

Microsoft Academic Search

Vav1 is a guanine nucleotide exchange factor essential in the development and function of ab lineage T cells. Here we report that in contrast to profound effects on pre-TCR- or ab TCR- dependent events in thymocyte development, Vav1 deficiency has no detectable effect on the development of gd T cells. Strikingly, however, these gd T cells are markedly deficient in

Wojciech Swat; Ramnik Xavier; Atsushi Mizoguchi; Emiko Mizoguchi; Jessica Fredericks; Keiko Fujikawa; Atul K. Bhan; Frederick W. Alt



Statistical Physics of T-Cell Development and Pathogen Specificity  

NASA Astrophysics Data System (ADS)

In addition to an innate immune system that battles pathogens in a nonspecific fashion, higher organisms, such as humans, possess an adaptive immune system to combat diverse (and evolving) microbial pathogens. Remarkably, the adaptive immune system mounts pathogen-specific responses, which can be recalled upon reinfection with the same pathogen. It is difficult to see how the adaptive immune system can be preprogrammed to respond specifically to a vast and unknown set of pathogens. Although major advances have been made in understanding pertinent molecular and cellular phenomena, the precise principles that govern many aspects of an immune response are largely unknown. We discuss complementary approaches from statistical mechanics and cell biology that can shed light on how key components of the adaptive immune system, T cells, develop to enable pathogen-specific responses against many diverse pathogens. The mechanistic understanding that emerges has implications for how host genetics may influence the development of T cells with differing responses to the human immunodeficiency virus (HIV) infection.

Košmrlj, Andrej; Kardar, Mehran; Chakraborty, Arup K.



Defect in recruiting effector memory CD8+ T-cells in malignant pleural effusions compared to normal pleural fluid  

PubMed Central

Background Malignant pleural effusions (MPE) are a common and fatal complication in cancers including lung or breast cancers, or malignant pleural mesothelioma (MPM). MPE animal models and immunotherapy trials in MPM patients previously suggested defects of the cellular immunity in MPE. However only few observational studies of the immune response were done in MPM patients, using questionable control groups (transudate…). Methods We compared T cell populations evaluated by flow cytometry from blood and pleural effusion of untreated patients with MPM (n?=?58), pleural metastasis of adenocarcinoma (n?=?30) or with benign pleural lesions associated with asbestos exposure (n?=?23). Blood and pleural fluid were also obtained from healthy subjects, providing normal values for T cell populations. Results Blood CD4+ or CD8+ T cells percentages were similar in all groups of patients or healthy subjects. Whereas pleural fluid from healthy controls contained mainly CD8+ T cells, benign or malignant pleural effusions included mainly CD4+ T cells. Effector memory T cells were the main T cell subpopulation in pleural fluid from healthy subjects. In contrast, there was a striking and selective recruitment of central memory CD4+ T cells in MPE, but not of effector cells CD8+ T cells or NK cells in the pleural fluid as one would expect in order to obtain an efficient immune response. Conclusions Comparing for the first time MPE to pleural fluid from healthy subjects, we found a local defect in recruiting effector CD8+ T cells, which may be involved in the escape of tumor cells from immune response. Further studies are needed to characterize which subtypes of effector CD8+ T cells are involved, opening prospects for cell therapy in MPE and MPM. PMID:23816056



Development of regulatory T cells requires IL-7R? stimulation by IL-7 or TSLP  

PubMed Central

Interleukin-7 (IL-7), a cytokine produced by stromal cells, is required for thymic development and peripheral homeostasis of most major subsets of T cells. We examined whether regulatory T (Treg) cells also required the IL-7 pathway by analyzing IL-7R??/? mice. We observed a striking reduction in cells with the Treg surface phenotype (CD4, CD25, GITR (glucocorticoid-induced tumor necrosis factor [TNF]-like receptor), CD45RB, CD62L, CD103) or intracellular markers (cytotoxic T-lymphocyte–associated antigen-4, CTLA-4, and forkhead box transcription factor 3, Foxp3). Foxp3 transcripts were virtually absent in IL-7R??/? lymphoid tissues, and no Treg cell suppressive activity could be detected. There are 2 known ligands for IL-7R?: IL-7 itself and thymic stromal lymphopoietin (TSLP). Surprisingly, mice deficient in IL-7 or the other chain of the TSLP receptor (TSLPR) developed relatively normal numbers of Treg cells. Combined deletion of IL-7 and TSLP receptor greatly reduced Treg cell development in the thymus but was not required for survival of mature peripheral Treg cells. We conclude that Treg cells, like other T cells, require signals from the IL-7 receptor, but unlike other T cells, do not require IL-7 itself because of at least partially overlapping actions of IL-7 and TSLP for development of Treg cells. PMID:18664628

Mazzucchelli, Renata; Hixon, Julie A.; Spolski, Rosanne; Chen, Xin; Li, Wen Qing; Hall, Veronica L.; Willette-Brown, Jami; Hurwitz, Arthur A.; Leonard, Warren J.



Regulation of early T cell development by the PHD finger of histone lysine methyltransferase ASH1  

SciTech Connect

We have previously isolated a mammalian homologue of Drosophila discsabsent, small, orhomeotic-1 (ash1) from the murine thymus, and recently shown that its SET domain methylates histone H3 lysine 36 (K36). Expression of ASH1 has been reported to be increased in NOD thymocytes in a BDC2.5 clonotype background, but its function in T cell development has remained elusive. Here we report that the ash1 gene is expressed at high levels in thymocytes of mice deficient for rag1 or tcra genes. ASH1 proteins are present at peri-nuclei and as nuclear speckles in thymocytes. Some of the nuclear ASH1 co-localize with RAG2. Expression of the evolutionarily conserved PHD finger of ASH1 impairs T cell development at the DP stage, and causes increased transcription from the HoxA9 promoter in vitro. Moreover, the C-terminal part of ASH1 interacts with HDAC1 repression complexes, suggesting that the PHD finger of ASH1 may be involved in down-regulation of genes for normal development of {alpha}{beta} T cells.

Tanaka, Yujiro [Genome Structure and Expression, School of Biomedical Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyoku, Tokyo 113-8610 (Japan)], E-mail:; Nakayama, Yasuhiro [Department of Genetics, Yale University School of Medicine, 300 Cedar St., New Haven, CT 06510 (United States); Taniguchi, Masaru [Department of Developmental Immunology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Kioussis, Dimitris [Department of Molecular Immunology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA (United Kingdom)



T-cell receptor V beta expression in normal human skin.  

PubMed Central

The skin-associated immune system is the first line of defense against pathogenic attack from the environment and is simultaneously tolerant to localized autoantigens and to antigens of the normal microbial flora. The T-cell receptor (TCR) repertoire of skin lymphocytes may therefore be influenced by the skin microenvironment. We studied the expression of TCR beta-chain variable region (V beta) genes in normal skin by a polymerase chain reaction-based comparative method. When comparing the amplification of V beta genes in peripheral blood and normal skin, we found that TCR V beta 1, -7, -14, and -16 were often highly expressed in skin relative to peripheral blood, whereas V beta 5.1 was often highly expressed in peripheral blood mononuclear cells but not in skin. These results demonstrate that the TCR repertoire of skin lymphocytes is not determined by random sampling of peripheral blood mononuclear cells but may be molded by the interaction with self antigens and/or the normal microbial flora in the microenvironment of the skin. Images PMID:7679496

Dunn, D A; Gadenne, A S; Simha, S; Lerner, E A; Bigby, M; Bleicher, P A



Macrophages suppress T cell responses and arthritis development in mice by producing reactive oxygen species.  


Reduced capacity to produce ROS increases the severity of T cell-dependent arthritis in both mice and rats with polymorphisms in neutrophil cytosolic factor 1 (Ncf1) (p47phox). Since T cells cannot exert oxidative burst, we hypothesized that T cell responsiveness is downregulated by ROS produced by APCs. Macrophages have the highest burst capacity among APCs, so to study the effect of macrophage ROS on T cell activation, we developed transgenic mice expressing functional Ncf1 restricted to macrophages. Macrophage-restricted expression of functional Ncf1 restored arthritis resistance to the level of that of wild-type mice in a collagen-induced arthritis model but not in a T cell-independent anti-collagen antibody-induced arthritis model. T cell activation was downregulated and skewed toward Th2 in transgenic mice. In vitro, IL-2 production and T cell proliferation were suppressed by macrophage ROS, irrespective of T cell origin. IFN-gamma production, however, was independent of macrophage ROS but dependent on T cell origin. These effects were antigen dependent but not restricted to collagen type II. In conclusion, macrophage-derived ROS play a role in T cell selection, maturation, and differentiation, and also a suppressive role in T cell activation, and thereby mediate protection against autoimmune diseases like arthritis. PMID:17909630

Gelderman, Kyra A; Hultqvist, Malin; Pizzolla, Angela; Zhao, Ming; Nandakumar, Kutty Selva; Mattsson, Ragnar; Holmdahl, Rikard



Differential Function of Themis CABIT Domains during T Cell Development  

PubMed Central

Themis (also named Gasp) is a newly identified Grb2-binding protein that is essential for thymocyte positive selection. Despite the possible involvement of Themis in TCR-mediated signal transduction, its function remains unresolved and controversial. Themis contains two functionally uncharacterized regions called CABIT (cysteine-containing, all-? in Themis) domains, a nuclear localization signal (NLS), and a proline-rich sequence (PRS). To elucidate the role of these motifs in Themis’s function in vivo, we established a series of mutant Themis transgenic mice on a Themis?/? background. Deletion of the highly conserved Core motif of CABIT1 or CABIT2 (Core1 or Core2, respectively), the NLS, or the PRS abolished Grb2-association, as well as TCR-dependent tyrosine-phosphorylation and the ability to induce positive selection in the thymus. The NLS and Core1 motifs were required for the nuclear localization of Themis, whereas Core2 and PRS were not. Furthermore, expression of ?Core1- but not ?Core2-Themis conferred dominant negative-type inhibition on T cell development. Collectively, our current results indicate that PRS, NLS, CABIT1, and CABIT2 are all required for positive selection, and that each of the CABIT domains exerts distinct functions during positive selection. PMID:24586531

Kaji, Kentaro; Takashima, Akiko; Oda, Hiroyo; Tamehiro, Norimasa; Goto, Motohito; Okamura, Tadashi; Patrick, Michael S.; Suzuki, Harumi



Loss of CNS IL-2 gene expression modifies brain T lymphocyte trafficking: Response of normal versus autoreactive Treg-deficient T cells  

PubMed Central

Emerging data from our lab and others suggested that dysregulation of the brain’s endogenous neuroimmunological milieu may occur with the loss of brain IL-2 gene expression and be involved in initiating processes that lead to CNS autoimmunity. We sought to test our working hypothesis that IL-2 deficiency induces endogenous changes in the CNS that play a key role in eliciting T cell homing into the brain. To accomplish this goal, we used an experimental approach that combined mouse congenic breeding and immune reconstitution. In congenic mice without brain IL-2 (two IL-2 KO alleles) that were reconstituted with a normal wild-type immune system, the loss of brain IL-2 doubled the number of T cells that trafficked into the brain in all regions quantified (hippocampus, septum, and cerebellum) compared to mice with two wild-type brain IL-2 alleles and a wild-type peripheral immune system. Congenic mice with normal brain IL-2 (two wild-type IL-2 alleles) that were immune reconstituted with autoreactive Treg-deficient T cells from IL-2 KO mice developed the expected peripheral autoimmunity (splenomegaly) and had a comparable doubling of T cell trafficking into the hippocampus and septum, whereas they exhibited an additional two-fold proclivity for the cerebellum over the septohippocampal regions. Unlike brain trafficking of wild-type T cells, the increased homing of IL-2 KO T cells to the cerebellum was independent of brain IL-2 gene expression. These findings demonstrate that brain IL-2 deficiency induces endogenous CNS changes that may lead to the development of brain autoimmunity, and that autoreative Treg-deficient IL-2 KO T cells trafficking to the brain could have a proclivity to induce cerebellar neuropathology. PMID:21669253

Huang, Zhi; Meola, Danielle; Petitto, John M.



Dysfunction of irradiated thymus for the development of helper T cells  

SciTech Connect

The development of cytotoxic T cells and helper T cells in an intact or irradiated thymus was investigated. C57BL/6 (H-2b, Thy-1.2) mice were whole body-irradiated, or were irradiated with shielding over either the thymus or right leg and tail, and were transferred with 1.5 X 10(7) bone marrow cells from B10.Thy-1.1 mice (H-2b, Thy-1.1). At various days after reconstitution, thymus cells from the recipient mice were harvested and a peanut agglutinin low-binding population was isolated. This population was further treated with anti-Thy-1.2 plus complement to remove host-derived cells and was assayed for the frequency of cytotoxic T cell precursors (CTLp) and for the activity of helper T cells (Th). In the thymus of thymus-shielded and irradiated mice, Th activity reached normal control level by day 25, whereas CTLp frequency remained at a very low level during these days. In the thymus of whole body-irradiated mice, generation of CTLp was highly accelerated while that of Th was retarded, the period required for reconstitution being 25 days and more than 42 days for CTLp and Th, respectively. Preferential development of CTLp was also seen in right leg- and tail-shielded (L-T-shielded) and irradiated recipients. Histological observation indicated that Ia+ nonlymphoid cells were well preserved in the thymus of thymus-shielded and irradiated recipients, whereas in L-T-shielded and irradiated recipients, such cells in the medulla were markedly reduced in number. These results suggest strongly that the generation of Th but not CTLp is dependent on radiosensitive thymic component(s), and that such components may represent Ia+ cells themselves in the medulla or some microenvironment related to Ia+ cells.

Amagai, T.; Kina, T.; Hirokawa, K.; Nishikawa, S.; Imanishi, J.; Katsura, Y.



Evidence for a stepwise program of extrathymic T cell development within the human tonsil  

PubMed Central

The development of a broad repertoire of T cells, which is essential for effective immune function, occurs in the thymus. Although some data suggest that T cell development can occur extrathymically, many researchers remain skeptical that extrathymic T cell development has an important role in generating the T cell repertoire in healthy individuals. However, it may be important in the setting of poor thymic function or congenital deficit and in the context of autoimmunity, cancer, or regenerative medicine. Here, we report evidence that a stepwise program of T cell development occurs within the human tonsil. We identified 5 tonsillar T cell developmental intermediates: (a) CD34+CD38dimLin– cells, which resemble multipotent progenitors in the bone marrow and thymus; (b) more mature CD34+CD38brightLin– cells; (c) CD34+CD1a+CD11c– cells, which resemble committed T cell lineage precursors in the thymus; (d) CD34–CD1a+CD3–CD11c– cells, which resemble CD4+CD8+ double-positive T cells in the thymus; and (e) CD34–CD1a+CD3+CD11c– cells. The phenotype of each subset closely resembled that of its thymic counterpart. The last 4 populations expressed RAG1 and PTCRA, genes required for TCR rearrangement, and all 5 subsets were capable of ex vivo T cell differentiation. TdT+ cells found within the tonsillar fibrous scaffold expressed CD34 and/or CD1a, indicating that this distinct anatomic region contributes to pre–T cell development, as does the subcapsular region of the thymus. Thus, we provide evidence of a role for the human tonsil in a comprehensive program of extrathymic T cell development. PMID:22378041

McClory, Susan; Hughes, Tiffany; Freud, Aharon G.; Briercheck, Edward L.; Martin, Chelsea; Trimboli, Anthony J.; Yu, Jianhua; Zhang, Xiaoli; Leone, Gustavo; Nuovo, Gerard; Caligiuri, Michael A.



Differential requirement for CCR4 and CCR7 during the development of innate and adaptive ??T cells in the adult thymus.  


??T cell development depends upon serial migration of thymocyte precursors through cortical and medullary microenvironments, enabling specialized stromal cells to provide important signals at specific stages of their development. Although conventional ??T cells are subject to clonal deletion in the medulla, entry into the thymus medulla also fosters ??T cell differentiation. For example, during postnatal periods, the medulla is involved in the intrathymic generation of multiple ??T cell lineages, notably the induction of Foxp3(+) regulatory T cell development and the completion of invariant NKT cell development. Although migration of conventional ??T cells to the medulla is mediated by the chemokine receptor CCR7, how other T cell subsets gain access to medullary areas during their normal development is not clear. In this study, we show that combining a panel of thymocyte maturation markers with cell surface analysis of CCR7 and CCR4 identifies distinct stages in the development of multiple ??T cell lineages in the thymus. Although Aire regulates expression of the CCR4 ligands CCL17 and CCL22, we show that CCR4 is dispensable for thymocyte migration and development in the adult thymus, demonstrating defective T cell development in Aire(-/-) mice is not because of a loss of CCR4-mediated migration. Moreover, we reveal that CCR7 controls the development of invariant NKT cells by enabling their access to IL-15 trans-presentation in the thymic medulla and influences the balance of early and late intrathymic stages of Foxp3(+) regulatory T cell development. Collectively, our data identify novel roles for CCR7 during intrathymic T cell development, highlighting its importance in enabling multiple ??T cell lineages to access the thymic medulla. PMID:24990081

Cowan, Jennifer E; McCarthy, Nicholas I; Parnell, Sonia M; White, Andrea J; Bacon, Andrea; Serge, Arnauld; Irla, Magali; Lane, Peter J L; Jenkinson, Eric J; Jenkinson, William E; Anderson, Graham



Differential Requirement for CCR4 and CCR7 during the Development of Innate and Adaptive ??T Cells in the Adult Thymus  

PubMed Central

??T cell development depends upon serial migration of thymocyte precursors through cortical and medullary microenvironments, enabling specialized stromal cells to provide important signals at specific stages of their development. Although conventional ??T cells are subject to clonal deletion in the medulla, entry into the thymus medulla also fosters ??T cell differentiation. For example, during postnatal periods, the medulla is involved in the intrathymic generation of multiple ??T cell lineages, notably the induction of Foxp3+ regulatory T cell development and the completion of invariant NKT cell development. Although migration of conventional ??T cells to the medulla is mediated by the chemokine receptor CCR7, how other T cell subsets gain access to medullary areas during their normal development is not clear. In this study, we show that combining a panel of thymocyte maturation markers with cell surface analysis of CCR7 and CCR4 identifies distinct stages in the development of multiple ??T cell lineages in the thymus. Although Aire regulates expression of the CCR4 ligands CCL17 and CCL22, we show that CCR4 is dispensable for thymocyte migration and development in the adult thymus, demonstrating defective T cell development in Aire?/? mice is not because of a loss of CCR4-mediated migration. Moreover, we reveal that CCR7 controls the development of invariant NKT cells by enabling their access to IL-15 trans-presentation in the thymic medulla and influences the balance of early and late intrathymic stages of Foxp3+ regulatory T cell development. Collectively, our data identify novel roles for CCR7 during intrathymic T cell development, highlighting its importance in enabling multiple ??T cell lineages to access the thymic medulla. PMID:24990081

Cowan, Jennifer E.; McCarthy, Nicholas I.; Parnell, Sonia M.; White, Andrea J.; Bacon, Andrea; Serge, Arnauld; Irla, Magali; Lane, Peter J. L.; Jenkinson, Eric J.; Jenkinson, William E.



Foxp3 programs the development and function of CD4+CD25+ regulatory T cells  

Microsoft Academic Search

CD4+CD25+ regulatory T cells are essential for the active suppression of autoimmunity. Here we report that the forkhead transcription factor Foxp3 is specifically expressed in CD4+CD25+ regulatory T cells and is required for their development. The lethal autoimmune syndrome observed in Foxp3-mutant scurfy mice and Foxp3-null mice results from a CD4+CD25+ regulatory T cell deficiency and not from a cell-intrinsic

Jason D. Fontenot; Marc A. Gavin; Alexander Y. Rudensky



STAT6 expression in T cells, alveolar macrophages and bronchial biopsies of normal and asthmatic subjects  

PubMed Central

Background Asthma is characterised by increased numbers of Th2-like cells in the airways and IgE secretion. Generation of Th2 cells requires interleukin (IL)-4 and IL-13 acting through their specific receptors and activating the transcription factor, signal transducer and activator of transcription 6 (STAT6). STAT6 knockout mice fail to produce IgE, airway hyperresponsiveness and bronchoalveolar lavage eosinophilia after allergen sensitisation, suggesting a critical role for STAT6 in allergic responses. Methods We have investigated the expression of STAT6 in peripheral blood T-lymphocytes, alveolar macrophages and bronchial biopsies from 17 normal subjects and 18 mild-moderate steroid-naïve stable asthmatic patients. Results STAT6 expression was variable and was detected in T-lymphocytes, macrophages and bronchial epithelial cells from all subjects with no difference between normal and stable asthmatic subjects. Conclusions STAT6 expression in different cells suggests that it may be important in regulating the expression of not only Th2-like cytokines in T cells of man, but may also regulate STAT-inducible genes in alveolar macrophages and airway epithelial cells. PMID:22401596



Specificity for the tumor-associated self-antigen WT1 drives the development of fully functional memory T cells in the absence of vaccination.  


Recently, vaccines against the Wilms Tumor antigen 1 (WT1) have been tested in cancer patients. However, it is currently not known whether physiologic levels of WT1 expression in stem and progenitor cells of normal tissue result in the deletion or tolerance induction of WT1-specific T cells. Here, we used an human leukocyte antigen-transgenic murine model to study the fate of human leukocyte antigen class-I restricted, WT1-specific T cells in the thymus and in the periphery. Thymocytes expressing a WT1-specific T-cell receptor derived from high avidity human CD8 T cells were positively selected into the single-positive CD8 population. In the periphery, T cells specific for the WT1 antigen differentiated into CD44-high memory phenotype cells, whereas T cells specific for a non-self-viral antigen retained a CD44(low) naive phenotype. Only the WT1-specific T cells, but not the virus-specific T cells, displayed rapid antigen-specific effector function without prior vaccination. Despite long-term persistence of WT1-specific memory T cells, the animals did not develop autoimmunity, and the function of hematopoietic stem and progenitor cells was unimpaired. This is the first demonstration that specificity for a tumor-associated self-antigen may drive differentiation of functionally competent memory T cells. PMID:21447831

Pospori, Constandina; Xue, Shao-An; Holler, Angelika; Voisine, Cecile; Perro, Mario; King, Judith; Fallah-Arani, Farnaz; Flutter, Barry; Chakraverty, Ronjon; Stauss, Hans J; Morris, Emma C



T-Cell Development in Early Partially Decapitated Chicken Embryos  

PubMed Central

We have evaluated the immunohistological and cytofluorometric changes that occur in the thymus of chicken embryos partially decapitated at 33-38 hr of incubation (DCx embryos) in an attempt to analyze possible neuroendocrinological influences on T-cell differentiation and, indirectly, the ontogeny of the so-called neuroendocrine-immune network. The thymus of DCx embryos shows important variations that profoundly and selectively affect different T-cell subsets, but not the nonlymphoid cell components of thymic stroma. These modifications include the accumulation of cell precursors, mainly DN (CD4- CD8-) cells and immature CD8high CD4- cells, which expand but do not differentiate, resulting in an extreme decline of both DP (CD4+ CD8+) cells and TcR c-expressing cells. Accordingly, both subcapsulary and outer cortex increase in size, whereas the deep cortex and principally the thymic medulla almost disappear in DCx embryos. In contrast, other T-cell subsets of DCx embryos, largely CDgglowCD4- cells and TcR ??-expressing cells do not undergo significant variations throughout thymic ontogeny. PMID:8770560

Moreno, Javier; Vicente, Angeles; Varas, Alberto



Immuno-miRs: critical regulators of T-cell development, function and ageing.  


MicroRNAs (miRNAs) are instrumental to many aspects of immunity, including various levels of T-cell immunity. Over the last decade, crucial immune functions were shown to be regulated by specific miRNAs. These 'immuno-miRs' regulate generic cell biological processes in T cells, such as proliferation and apoptosis, as well as a number of T-cell-specific features that are fundamental to the development, differentiation and function of T cells. In this review, we give an overview of the current literature with respect to the role of miRNAs at various stages of T-cell development, maturation, differentiation, activation and ageing. Little is known about the involvement of miRNAs in thymic T-cell development, although miR-181a and miR-150 have been implicated herein. In contrast, several broadly expressed miRNAs including miR-21, miR-155 and miR-17~92, have now been shown to regulate T-cell activation. Other miRNAs, including miR-146a, show a more T-cell-subset-specific expression pattern and are involved in the regulation of processes unique to that specific T-cell subset. Importantly, differences in the miRNA target gene repertoires of different T-cell subsets allow similar miRNAs to control different T-cell-subset-specific functions. Interestingly, several of the here described immuno-miRs have also been implicated in T-cell ageing and there are clear indications for causal involvement of miRNAs in immunosenescence. It is concluded that immuno-miRs have a dynamic regulatory role in many aspects of T-cell differentiation, activation, function and ageing. An important notion when studying miRNAs in relation to T-cell biology is that specific immuno-miRs may have quite unrelated functions in closely related T-cell subsets. PMID:25093579

Kroesen, Bart-Jan; Teteloshvili, Nato; Smigielska-Czepiel, Katarzyna; Brouwer, Elisabeth; Boots, Anne Mieke H; van den Berg, Anke; Kluiver, Joost



Purification of normal lymphocytes from leukemic T-cells by lectin-affinity adsorbents - correlation with lectin-cell binding.  


Utilization of leukemic T-cells from normal ones, using lectin-affinity adsorbents, is described. CNBr-activated Sepharose 6MB was covalently coupled to Soybean (SBA) or Dolichos Biflorus Agglutinins (DBA), then serves as an affinity probe for separation of leukemic T-cells from normal lymphocytes. The normal lymphocytes were removed almost completely by phosphate buffered saline (Ca(2+) and Mg(2+) free) (PBS(-)) from lectin-affinity column. More than 80% of the leukemic T-cells were retained on the lectin-affinity adsorbent, whereas another 10-15% were easily removed by PBS(-). There was a very good linear correlation between percent of cells, retained on the lectin-affinity adsorbent and percent of cells, interacting with the respective free lectin (r=0.97 for SBA, and r=0.93 for DBA). The viability of normal lymphocytes was not influenced after passing through the columns. In the case of leukemic T-cells - about 90% of the easily removed cells were dead, and another 10% were viable cells, non-interacting with DBA or SBA. PMID:12637153

Bakalova, R; Ohba, H



A role for CD44 in T cell development and function during direct competition between CD44+ and CD44- cells.  


The role of CD44 in T cell biology remains incompletely understood. Although studies using anti-CD44 antibodies have implicated this cell adhesion molecule in a variety of important T cell processes, few T cell defects have been reported in CD44-deficient mice. We have assessed the requirement for CD44 in T cell development and mature T cell function by analyzing mice in which CD44(-/-) and WT cells were produced simultaneously. In mixed (CD44(-/-) + CD44(+/+)) bone marrow chimeras, production of CD44(-/-) T cells was shown to be reduced compared to WT cells due to inefficient intrathymic development. In addition, mature CD44(-/-) CD8(+) T cells generated a substantially lower response than WT T cells after infection of mice with lymphocytic choriomeningitis virus, with the reduction in response apparent in both lymphoid and non-lymphoid tissues. Overall, these results demonstrate a poor capacity of CD44(-/-) T lineage cells to compete with WT cells at multiple levels, implicating CD44 in normal T cell function. PMID:17330818

Graham, Victoria A; Marzo, Amanda L; Tough, David F



Human CD4(+) T cells recognize an epitope within alpha-fetoprotein sequence and develop into TGF-beta-producing CD4(+) T cells.  


There is limited information on the influence of tumor growth on the expansion of tumor-specific TGF-beta-producing CD4(+) T cells in humans. alpha-Fetoprotein (AFP) is an oncofetal Ag and has intrinsic immunoregulatory properties. In this study, we report the identification and characterization of subsets of CD4(+) T cells that recognize an epitope within the AFP sequence (AFP(46-55)) and develop into TGF-beta-producing CD4(+) T cells. In a peptide-specific and dose-dependent manner, AFP(46-55) CD4(+) T cells produce TGF-beta, GM-CSF, and IL-2 but not Th1-, Th2-, Th17-, or Tr1-type cytokines. These cells express CTLA-4 and glucocorticoid-induced TNR receptor and inhibit T cell proliferation in a contact-dependent manner. In this study, we show that the frequency of AFP(46-55) CD4(+) T cells is significantly higher (p = 001) in patients with hepatocellular carcinoma than in healthy donors, suggesting that these cells are expanded in response to tumor Ag. In contrast, tumor necrosis-inducing treatments that are shown to improve survival rate can shift the Th1/TGF-beta-producing CD4(+) T cell balance in favor of Th1 responses. Our data demonstrate that tumor Ags may contain epitopes which activate the expansion of inducible regulatory T cells, leading to evasion of tumor control. PMID:18354237

Alisa, Akeel; Boswell, Sandra; Pathan, Ansar A; Ayaru, Lakshmana; Williams, Roger; Behboudi, Shahriar



Regulation of Lipid Signaling by Diacylglycerol Kinases during T Cell Development and Function  

PubMed Central

Diacylglycerol (DAG) and phosphatidic acid (PA) are bioactive lipids synthesized when the T cell receptor binds to a cognate peptide-MHC complex. DAG triggers signaling by recruiting Ras guanyl-releasing protein 1, PKC?, and other effectors, whereas PA binds to effector molecules that include mechanistic target of rapamycin, Src homology region 2 domain-containing phosphatase 1, and Raf1. While DAG-mediated pathways have been shown to play vital roles in T cell development and function, the importance of PA-mediated signals remains less clear. The diacylglycerol kinase (DGK) family of enzymes phosphorylates DAG to produce PA, serving as a molecular switch that regulates the relative levels of these critical second messengers. Two DGK isoforms, ? and ?, are predominantly expressed in T lineage cells and play an important role in conventional ?? T cell development. In mature T cells, the activity of these DGK isoforms aids in the maintenance of self-tolerance by preventing T cell hyper-activation and promoting T cell anergy. In this review, we discuss the roles of DAG-mediated pathways, PA-effectors, and DGKs in T cell development and function. We also highlight recent work that has uncovered previously unappreciated roles for DGK activity, for instance in invariant NKT cell development, anti-tumor and anti-viral CD8 responses, and the directional secretion of soluble effectors. PMID:23847619

Krishna, Sruti; Zhong, Xiao-Ping



Development of Promyelocytic Zinc Finger and ThPOK-Expressing Innate ?? T Cells Is Controlled by Strength of TCR Signaling and Id3  

PubMed Central

The broad-complex tramtrack and bric a brac-zinc finger transcriptional regulator(BTB-ZF), promyelocytic leukemia zinc finger (PLZF), was recently shown to control the development of the characteristic innate T cell phenotype and effector functions of NK T cells. Interestingly, the ectopic expression of PLZF was shown to push conventional T cells into an activated state that seems to be proinflammatory. The factors that control the normal expression of PLZF in lymphocytes are unknown. In this study, we show that PLZF expression is not restricted to NK T cells but is also expressed by a subset of ?? T cells, functionally defining distinct subsets of this innate T cell population. A second BTB-ZF gene, ThPOK, is important for the phenotype of the PLZF-expressing ?? T cells. Most importantly, TCR signal strength and expression of inhibitor of differentiation gene 3 control the frequency of PLZF-expressing ?? T cells. This study defines the factors that control the propensity of the immune system to produce potentially disease-causing T cell subsets. PMID:20038637

Alonzo, Eric S.; Gottschalk, Rachel A.; Das, Joy; Egawa, Takeshi; Hobbs, Robin M.; Pandolfi, Pier Paolo; Pereira, Pablo; Nichols, Kim E.; Koretzky, Gary A.; Jordan, Martha S.; Sant’Angelo, Derek B.



Development of Human T-Cell Leukemia Virus Type 1-Transformed Tumors in Rats following Suppression of T-Cell Immunity by CD80 and CD86 Blockade  

Microsoft Academic Search

Host immunity influences clinical manifestations of human T-cell leukemia virus type 1 (HTLV-1) infection. In this study, we demonstrated that HTLV-1-transformed tumors could develop in immunocompetent rats by blocking a costimulatory signal for T-cell immune responses. Four-week-old WKA\\/HKm rats were treated with monoclonal antibodies (MAbs) to CD80 and CD86 and subcutaneously inoculated with syngeneic HTLV-1- infected TARS-1 cells. During MAb




Interleukin-7 receptor alpha is essential for the development of gamma delta + T cells, but not natural killer cells  

PubMed Central

Mice that lack a functional gamma c subunit of the receptors for interleukin (IL)-2, IL-4, IL-7, IL-9, and IL-15 display profound defects in lymphoid development. The IL-7/IL-7R system represents a critical interaction for conventional T and B cell development. In this report, the role of IL-7R alpha in the development of lymphoid lineages other than conventional T and B cells was examined. We demonstrate that gamma delta + T cells were absent in IL-7R alpha-deficient mice, whereas the development and function of natural killer cells were normal. Thus, IL-7R alpha function is required for the development of gamma delta + T cells but not natural killer cells. PMID:8691145



Activation of CD4? Foxp3? regulatory T cells proceeds normally in the absence of B cells during EAE.  


B cells and regulatory T (Treg) cells can both facilitate remission from experimental auto immune encephalomyelitis (EAE), a disease of the central nervous system (CNS) used as a model for multiple sclerosis (MS). Considering that B-cell-depletion therapy (BCDT) is used to treat MS patients, we asked whether Treg-cell activation depended on B cells during EAE. Treg-cell proliferation, accumulation in CNS, and augmentation of suppressive activity in the CNS were normal in B-cell-deficient mice, indicating that B cells are not essential for activation of the protective Treg-cell response and thus provide an independent layer of regulation. This function of B cells involved early suppression of the encephalitogenic CD4(+) T-cell response, which was enhanced in B-cell-deficient mice. CD4(+) T-cell depletion was sufficient to intercept the transition from acute-to-chronic EAE when applied to B-cell-deficient animals that just reached the peak of disease severity. Intriguingly, this treatment did not improve disease when applied later, implying that chronic disability was ultimately maintained independently of pathogenic CD4(+) T cells. Collectively, our data indicate that BCDT is unlikely to impair Treg-cell function, yet it might produce undesirable effects on T-cell-mediated autoimmune pathogenesis. PMID:22539290

Hoehlig, Kai; Shen, Ping; Lampropoulou, Vicky; Roch, Toralf; Malissen, Bernard; O'Connor, Richard; Ries, Stefanie; Hilgenberg, Ellen; Anderton, Stephen M; Fillatreau, Simon



Induction of T Cell Development from Hematopoietic Progenitor Cells by Delta-like-1 In Vitro  

Microsoft Academic Search

The molecular interactions provided by the thymic microenvironment that predicate T cell development remain obscure. Here, we show that a bone marrow stromal cell line ectopically expressing the Notch ligand Delta-like-1 loses its ability to support B cell lymphopoiesis, but acquires the capacity to induce the differentiation of hematopoietic progenitors into CD4 CD8 double- and single-positive T cells. Both ??-TCR+

Thomas M. Schmitt; Juan Carlos Zúñiga-Pflücker



Control of Regulatory T Cell Development by the Transcription Factor Foxp3  

Microsoft Academic Search

Regulatory T cells engage in the maintenance of immunological self-tolerance by actively suppressing self-reactive lymphocytes. Little is known, however, about the molecular mechanism of their development. Here we show that Foxp3, which encodes a transcription factor that is genetically defective in an autoimmune and inflammatory syndrome in humans and mice, is specifically expressed in naturally arising CD4+ regulatory T cells.

Shohei Hori; Takashi Nomura; Shimon Sakaguchi



GATA3 controls the expression of CD5 and the T cell receptor during CD4 T cell lineage development.  


The transcription factor GATA3 is essential at multiple stages of T cell development, including the earliest double-negative stages, beta-selection and CD4 single-positive thymocytes. Here, we show that in CD2-GATA3 transgenic mice, with enforced GATA3 expression driven by the CD2 promoter, thymocytes have reduced levels of CD5, which is a negative regulator of TCR signaling participating in TCR repertoire fine-tuning. Reduction of CD5 expression was most prominent in CD4(+)CD8(+) double-positive (DP) cells and was associated with increased levels of the transcription factor E2A. Conversely, GATA3-deficient DP thymocytes showed consistently higher CD5 levels and defective TCR up-regulation during their development towards the CD4(lo)CD8(lo) subpopulation. CD2-GATA3 transgenic mice carrying the MHC class II-restricted TCR DO11.10 also manifested decreased CD5 levels. As in these TCR-transgenic mice reduced CD5 expression cannot result from an effect of GATA3 on repertoire selection, we conclude that enforced GATA3 interferes with the developmentally regulated increase of CD5 levels. Enforced GATA3 expression in DO11.10 transgenic mice was also accompanied by enhanced TCR expression during CD4 positive selection. Because GATA3 is induced by TCR signaling in DP thymocytes, our findings indicate that GATA3 establishes a positive feedback loop that increases TCR surface expression in developing CD4 lineage cells. PMID:17357106

Ling, Kam-Wing; van Hamburg, Jan Piet; de Bruijn, Marjolein J W; Kurek, Dorota; Dingjan, Gemma M; Hendriks, Rudolf W



Thymic Stromal-Cell Abnormalities and Dysregulated T-Cell Development in IL-2-Deficient Mice  

PubMed Central

The role that interleukin-2 (IL-2) plays in T-cell development is not known. To address this issue, we have investigated the nature of the abnormal thymic development and autoimmune disorders that occurs in IL-2-deficient (IL-2–/–) mice. After 4 to 5 weeks of birth, IL-2–/– mice progressively develop a thymic disorder resulting in the disruption of thymocyte maturation. This disorder is characterized by a dramatic reduction in cellularity, the selective loss of immature CD4-8- (double negative; DN) and CD4+8+ (double positive; DP) thymocytes and defects in the thymic stromal-cell compartment. Immunohistochemical staining of sections of thymuses from specific pathogen-free and germ-free IL-2–/– mice of various ages showed a progressive ,loss of cortical epithelial cells, MHC class II-expressing cells, monocytes, and macrophages. Reduced numbers of macrophages were apparent as early as week after birth. Since IL-2–/– thymocyte progenitor populations could mature normally on transfer into a normal thymus, the thymic defect in IL-2–/– mice appears to be due to abnormalities among thymic stromal cells. These results underscore the role of IL-2 in maintaining functional microenvironments that are necessary to support thymocyte growth, development, and selection. PMID:9814585

Reya, Tannishtha; Bassiri, Hamid; Biancaniello, Renée



T cells modulate glycans on CD43 and CD45 during development and activation, signal regulation, and survival  

PubMed Central

Glycosylation affects many essential T cell processes and is intrinsically controlled throughout the lifetime of a T cell. CD43 and CD45 are the two most abundant glycoproteins on the T cell surface and are decorated with O- and N-glycans. Global T cell glycosylation and specific glycosylation of CD43 and CD45 are modulated during thymocyte development and T cell activation; T cells control the type and abundance of glycans decorating CD43 and CD45 by regulating expression of glycosyltransferases and glycosidases. Additionally, T cells regulate glycosylation of CD45 by expressing alternatively spliced isoforms of CD45 that have different glycan attachment sites. The glycophenotype of CD43 and CD45 on T cells influences how T cells interact with the extracellular environment, including how T cells interact with endogenous lectins. This review focuses on changes in glycosylation of CD43 and CD45 occurring throughout T cell development and activation and the role that glycosylation plays in regulating T cell processes, such as migration, T cell receptor signaling, and apoptosis. PMID:22288421

Clark, Mary C.; Baum, Linda G.



The tyrosine kinase Itk suppresses CD8+ memory T cell development in response to bacterial infection  

PubMed Central

Vaccine efficacy depends on strong long-term development of immune memory and the formation of memory CD8+ T cells is critical for recall responses to infection. Upon antigen recognition by naïve T cells, the strength of the TcR signal influences the subsequent effector and memory cells differentiation. Here, we have examined the role of Itk, a tyrosine kinase critical for TcR signaling, in CD8+ effector and memory T cell differentiation during Listeria monocytogenes infection. We found that the reduced TcR signal strength in Itk deficient naïve CD8+ T cells enhances the generation of memory T cells during infection. This is accompanied by increased early Eomesodermin, IL-7R? expression and memory precursor effector cells. Furthermore, Itk is required for optimal cytokine production in responding primary effector cells, but not secondary memory responses. Our data suggests that Itk-mediated signals control the expression of Eomesodermin and IL-7R?, thus regulating the development of memory CD8+ T cells, but not subsequent response of memory cells. PMID:25567129

Huang, Fei; Huang, Weishan; Briggs, Jessica; Chew, Tina; Bai, Yuting; Deol, Simrita; August, Avery



Protecting and rescuing the effectors: roles of differentiation and survival in the control of memory T cell development  

PubMed Central

Vaccines, arguably the single most important intervention in improving human health, have exploited the phenomenon of immunological memory. The elicitation of memory T cells is often an essential part of successful long-lived protective immunity. Our understanding of T cell memory has been greatly aided by the development of TCR Tg mice and MHC tetrameric staining reagents that have allowed the precise tracking of antigen-specific T cell responses. Indeed, following acute infection or immunization, naïve T cells undergo a massive expansion culminating in the generation of a robust effector T cell population. This peak effector response is relatively short-lived and, while most effector T cells die by apoptosis, some remain and develop into memory cells. Although the molecular mechanisms underlying this cell fate decision remain incompletely defined, substantial progress has been made, particularly with regards to CD8+ T cells. For example, the effector CD8+ T cells generated during a response are heterogeneous, consisting of cells with more or less potential to develop into full-fledged memory cells. Development of CD8+ T cell memory is regulated by the transcriptional programs that control the differentiation and survival of effector T cells. While the type of antigenic stimulation and level of inflammation control effector CD8+ T cell differentiation, availability of cytokines and their ability to control expression and function of Bcl-2 family members governs their survival. These distinct differentiation and survival programs may allow for finer therapeutic intervention to control both the quality and quantity of CD8+ T cell memory. Effector to memory transition of CD4+ T cells is less well characterized than CD8+ T cells, emerging details will be discussed. This review will focus on the recent progress made in our understanding of the mechanisms underlying the development of T cell memory with an emphasis on factors controlling survival of effector T cells. PMID:23346085

Kurtulus, Sema; Tripathi, Pulak; Hildeman, David A.



Type C virus particles in a cord T-cell line derived by co-cultivating normal human cord leukocytes and human leukaemic T cells  

Microsoft Academic Search

A recent nationwide survey of the lymphocyte subpopulations of leukaemia and lymphoma in Japan has disclosed a high incidence of adult T-cell leukaemia (ATL)1. One of the striking features of this disease is the clustering of patients in the southwestern part of Japan1,2. We have established a continuous culture line of leukaemic T cells from a patient with ATL3,4. This

Isao Miyoshi; Ichiro Kubonishi; Shizuo Yoshimoto; Tadaatsu Akagi; Yuji Ohtsuki; Yukimasa Shiraishi; Kinya Nagata; Yorio Hinuma



Predominance of “memory” T cells (CD4+, CDw29+) over “naive” T cells (CD4+, CD45R+) in both normal and diseased human skin  

Microsoft Academic Search

Absolute numbers of CD3+ T lymphocytes and their subpopulations were determined and statistically evaluated in the lesional skin of psoriasis, atopic dermatitis, nummular dermatitis, pityriasis rosea, and lichen planus. Skin sections were divided into horizontal layers and the numbers of CD3+ T cells as well as CD4+ inducer and CD8+ suppressor-cytotoxic T-cell subsets were counted. In addition, absolute numbers of

J. D. Bos; C. Hagenaars; P. K. Das; S. R. Krieg; W. J. Voorn; M. L. Kapsenberg



Decidual infiltration of FoxP3? regulatory T cells, CD3? T cells, CD56? decidual natural killer cells and Ki-67 trophoblast cells in hydatidiform mole compared to normal and ectopic pregnancies.  


Hydatidiform moles are considered pre-cancerous lesions of gestational trophoblastic neoplasia and are associated with an aberrant immune response. This preliminary study aimed to evaluate the feasibility of measuring the presence of immune cells as potential prognostic markers for hydatidiform moles. Immunohistochemical staining of FoxP3? regulatory T cells, CD3? T cells, CD56? decidual natural killer cells and Ki-67? trophoblast cells was performed on 32 samples. Samples were from complete hydatidiform moles, partial hydatidiform moles, ectopic pregnancies, gestational age-matched normal elective pregnancy terminations (normal pregnancies) and gestational trophoblastic neoplasias. FoxP3? regulatory T-cell infiltration was highest in the complete hydatidiform moles and lowest in the normal pregnancy samples. The normal pregnancy cases showed significantly fewer FoxP3? regulatory T cells compared to the ectopic pregnancy cases (p=0.037) and compared to the combination of all of the other groups (p=0.044). Normal pregnancy samples also showed the lowest infiltration of CD3? T cells and the highest number of CD56? decidual natural killer cells; conversely, gestational trophoblastic neoplasias showed the highest infiltration of CD3? T cells and the lowest number of CD56? decidual natural killer cells. The numbers of Ki-67? trophoblast cells were highest in the gestational trophoblastic neoplasias (688/1,000 trophoblast cells) and lowest in the partial moles (87/1,000 trophoblast cells). Our results suggest that regulatory T cells may be involved in the progression of complete hydatidiform moles. A larger cohort study is required to assess whether immune cells are effective prognostic markers in gestational trophoblastic diseases. PMID:22002546

Sundara, Yayan T; Jordanova, Ekaterina S; Hernowo, Bethy S; Gandamihardja, Supriadi; Fleuren, Gert Jan



Developmental arrest of NK1.1+ T cell antigen receptor (TCR)- alpha/beta+ T cells and expansion of NK1.1+ TCR-gamma/delta+ T cell development in CD3 zeta-deficient mice  

PubMed Central

The relationship between the structure of the T cell antigen receptor (TCR)-CD3 complex and development of NK1.1+ T cells was investigated. The TCR complex of freshly isolated NK1.1+ TCR-alpha/beta+ thymocytes contained CD3 zeta homodimers and CD zeta-FcR gamma heterodimers, whereas that of the majority of NK1.1- T cells did not contain FcR gamma. The function of CD3 zeta and FcR gamma in the development of NK1.1+ T cells was determined by analyzing CD3 zeta- and FcR gamma- deficient mice. The NK1.1+ T cells from wild-type and CD3 zeta- deficient mice had equal levels of CD3 expression. However, the development of NK1.1+ TCR-alpha/beta+ T cells was almost completely disrupted in thymus and spleen in CD3 zeta-deficient mice, whereas no alteration was observed in FcR gamma-deficient mice. In contrast, the number of novel NK1.1+ TCR-gamma/delta+ thymocytes expressing a surface phenotype similar to NK1.1+ TCR-alpha/beta+ thymocytes increased approximately six times in CD3 zeta-deficient mice. These findings establish the distinct roles of the CD3 zeta chain in the development of the following different thymic T cell compartments: NK1.1- TCR+, NK1.1+ TCR-alpha/beta+, and NK1.1+ TCR-gamma/delta+ thymocytes, which cannot be replaced by CD3 eta or FcR gamma chains. PMID:7650493



Cutting edge: Thymic NK cells develop independently from T cell precursors.  


Although NK cells in the mouse are thought to develop in the bone marrow, a small population of NK cells in the thymus has been shown to derive from a GATA3-dependent pathway. Characteristically, thymic NK cells express CD127 and few Ly49 molecules and lack CD11b. Because these NK cells develop in the thymus, the question of their relationship to the T cell lineage has been raised. Using several different mouse models, we find that unlike T cells, thymic NK cells are not the progeny of Rorc-expressing progenitors and do not express Rag2 or rearrange the TCR? locus. We further demonstrate that thymic NK cells develop independently of the Notch signaling pathway, supporting the idea that thymic NK cells represent bona fide NK cells that can develop independently of all T cell precursors. PMID:20889548

Ribeiro, Vera S G; Hasan, Milena; Wilson, Anne; Boucontet, Laurent; Pereira, Pablo; Lesjean-Pottier, Sarah; Satoh-Takayama, Naoko; Di Santo, James P; Vosshenrich, Christian A J



Normally occurring NKG2D+CD4+ T cells are immunosuppressive and inversely correlated with disease activity in juvenile-onset lupus  

PubMed Central

The NKG2D receptor stimulates natural killer cell and T cell responses upon engagement of ligands associated with malignancies and certain autoimmune diseases. However, conditions of persistent NKG2D ligand expression can lead to immunosuppression. In cancer patients, tumor expression and shedding of the MHC class I–related chain A (MICA) ligand of NKG2D drives proliferative expansions of NKG2D+CD4+ T cells that produce interleukin-10 (IL-10) and transforming growth factor-?, as well as Fas ligand, which inhibits bystander T cell proliferation in vitro. Here, we show that increased frequencies of functionally equivalent NKG2D+CD4+ T cells are inversely correlated with disease activity in juvenile-onset systemic lupus erythematosus (SLE), suggesting that these T cells may have regulatory effects. The NKG2D+CD4+ T cells correspond to a normally occurring small CD4 T cell subset that is autoreactive, primed to produce IL-10, and clearly distinct from proinflammatory and cytolytic CD4 T cells with cytokine-induced NKG2D expression that occur in rheumatoid arthritis and Crohn's disease. As classical regulatory T cell functions are typically impaired in SLE, it may be clinically significant that the immunosuppressive NKG2D+CD4+ T cells appear functionally uncompromised in this disease. PMID:19289577

Dai, Zhenpeng; Turtle, Cameron J.; Booth, Garrett C.; Riddell, Stanley R.; Gooley, Theodore A.; Stevens, Anne M.; Spies, Thomas



From the cradle to the grave: activities of GATA-3 throughout T cell development and differentiation  

PubMed Central

Summary GATA family transcription factors play multiple vital roles in hematopoiesis in many cell lineages, and in particular, T cells require GATA-3 for execution of several developmental steps. Transcriptional activation of the Gata3 gene is observed throughout T-cell development and differentiation in stage-specific fashion. GATA-3 has been described as a master regulator of T-helper 2 (Th2) cell differentiation in mature CD4+ T cells. During T-cell development in the thymus, its roles in the CD4 vs. CD8 lineage choice and at the ?-selection checkpoint are the best characterized. In contrast, its importance prior to ?-selection has been obscured both by the developmental heterogeneity of double negative (DN) 1 thymocytes and the paucity of early T-lineage progenitors (ETPs), a subpopulation of DN1 cells that contains the most immature thymic progenitors that retain potent T-lineage developmental potential. By examining multiple lines of in vivo evidence procured through the analysis of Gata3 mutant mice, we have recently demonstrated that GATA-3 is additionally required at the earliest stage of thymopoiesis for the development of the ETP population. Here, we review the characterized functions of GATA-3 at each stage of T-cell development and discuss hypothetical molecular pathways that mediate these functions. PMID:20969588

Hosoya, Tomonori; Maillard, Ivan; Engel, James Douglas



SAP-Dependent and -Independent Regulation of Innate T Cell Development Involving SLAMF Receptors  

PubMed Central

Signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) plays an essential role in the immune system mediating the function of several members of the SLAM family (SLAMF) of receptors, whose expression is essential for T, NK, and B-cell responses. Additionally, the expression of SAP in double-positive thymocytes is mandatory for natural killer T (NKT) cells and, in mouse, for innate CD8+ T cell development. To date, only two members of the SLAMF of receptors, Slamf1 and Slamf6, have been shown to positively cooperate during NKT cell differentiation in mouse. However, it is less clear whether other members of this family may also participate in the development of these innate T cells. Here, we show that Slamf[1?+?6]?/? and Slamf[1?+?5?+?6]?/?B6 mice have ~70% reduction of NKT cells compared to wild-type B6 mice. Unexpectedly, the proportion of innate CD8+ T cells slightly increased in the Slamf[1?+?5?+?6]?/?, but not in the Slamf[1?+?6]?/? strain, suggesting that Slamf5 may function as a negative regulator of innate CD8+ T cell development. Accordingly, Slamf5?/? B6 mice showed an exclusive expansion of innate CD8+ T cells, but not NKT cells. Interestingly, the SAP-independent Slamf7?/? strain showed an expansion of both splenic innate CD8+ T cells and thymic NKT cells. On the other hand, and similar to what was recently shown in Slamf3?/? BALB/c mice, the proportions of thymic promyelocytic leukemia zinc finger (PLZFhi) NKT cells and innate CD8+ T cells significantly increased in the SAP-independent Slamf8?/? BALB/c strain. In summary, these results show that NKT and innate CD8+ T cell development can be regulated in a SAP-dependent and -independent fashion by SLAMF receptors, in which Slamf1, Slamf6, and Slamf8 affect development of NKT cells, and that Slamf5, Slamf7, and Slamf8 affect the development of innate CD8+ T cells. PMID:24795728

De Calisto, Jaime; Wang, Ninghai; Wang, Guoxing; Yigit, Burcu; Engel, Pablo; Terhorst, Cox



CD16+ monocytes control T-cell subset development in immune thrombocytopenia  

PubMed Central

Immune thrombocytopenia (ITP) results from decreased platelet production and accelerated platelet destruction. Impaired CD4+ regulatory T-cell (Treg) compartment and skewed Th1 and possibly Th17 responses have been described in ITP patients. The trigger for aberrant T-cell polarization remains unknown. Because monocytes have a critical role in development and polarization of T-cell subsets, we explored the contribution of monocyte subsets in control of Treg and Th development in patients with ITP. Unlike circulating classic CD14hiCD16? subpopulation, the CD16+ monocyte subset was expanded in ITP patients with low platelet counts on thrombopoietic agents and positively correlated with T-cell CD4+IFN-?+ levels, but negatively with circulating CD4+CD25hiFoxp3+ and IL-17+ Th cells. Using a coculture model, we found that CD16+ ITP monocytes promoted the expansion of IFN-?+CD4+ cells and concomitantly inhibited the proliferation of Tregs and IL-17+ Th cells. Th-1–polarizing cytokine IL-12, secreted after direct contact of patient T-cell and CD16+ monocytes, was responsible for the inhibitory effect on Treg and IL-17+CD4+ cell proliferation. Our findings are consistent with ITP CD16+ monocytes promoting Th1 development, which in turn negatively regulates IL-17 and Treg induction. This underscores the critical role of CD16+ monocytes in the generation of potentially pathogenic Th responses in ITP. PMID:22915651

Zhong, Hui; Bao, Weili; Li, Xiaojuan; Miller, Allison; Seery, Caroline; Haq, Naznin; Bussel, James



Bystander chronic infection negatively impacts development of CD8(+) T cell memory.  


Epidemiological evidence suggests that chronic infections impair immune responses to unrelated pathogens and vaccines. The underlying mechanisms, however, are unclear and distinguishing effects on priming versus development of immunological memory has been challenging. We investigated whether bystander chronic infections impact differentiation of memory CD8(+) T cells, the hallmark of protective immunity against intracellular pathogens. Chronic bystander infections impaired development of memory CD8(+) T cells in several mouse models and humans. These effects were independent of initial priming and were associated with chronic inflammatory signatures. Chronic inflammation negatively impacted the number of bystander CD8(+) T cells and their memory development. Distinct underlying mechanisms of altered survival and differentiation were revealed with the latter regulated by the transcription factors T-bet and Blimp-1. Thus, exposure to prolonged bystander inflammation impairs the effector to memory transition. These data have relevance for immunity and vaccination during persisting infections and chronic inflammation. PMID:24837104

Stelekati, Erietta; Shin, Haina; Doering, Travis A; Dolfi, Douglas V; Ziegler, Carly G; Beiting, Daniel P; Dawson, Lucas; Liboon, Jennifer; Wolski, David; Ali, Mohammed-Alkhatim A; Katsikis, Peter D; Shen, Hao; Roos, David S; Haining, W Nicholas; Lauer, Georg M; Wherry, E John



Molecular insights into the development of T cell-based immunotherapy for prostate cancer.  


Using a patient's own immune system to fight cancer is a highly active area of cancer research. Four years ago, sipuleucel-T became the first approved cancer vaccine, which was developed to enhance T-cell immunity against metastatic castration-resistant prostate cancer. Other prostate cancer vaccines, including a viral-based vaccine PROSTVAC-VF and a cellular vaccine GVAX, are in development. Moreover, several clinical trials are investigating the role of immune checkpoint blockade in the treatment of prostate cancer. Ipilimumab and nivolumab are potent T cell checkpoint inhibitors that reverse immunologic tolerance in multiple types of cancers. Here we discuss the mechanisms underlying antitumor T cell responses as well as the development of immunotherapies for prostate cancer. PMID:25259804

Dong, Baijun; Minze, Laurie J; Xue, Wei; Chen, Wenhao



Detailed analysis of gene expression during development of T cell lineages in the thymus  

PubMed Central

The genetic mechanisms that promote lineage commitment and eliminate autoreactive cells in the thymus are not well understood. To better understand this process, we have identified and quantitated transcripts in the two major thymocyte lineages by using serial analysis of gene expression. Approximately 25 genes displayed almost complete segregation to one or the other T cell lineage. Commitment to the CD4 lineage was marked by up-regulation of genes associated with increased survival and chaperone function followed by expression of genes that regulate nucleosome remodeling and T cell receptor signaling. Differentiation within the CD8 lineage, on the other hand, was marked by up-regulation of genes that regulate lymphocyte homing, followed by quenching of genes that inhibit apoptosis. Definition of differential gene expression during development of the two major thymocyte lineages will allow insight into mechanisms of T cell development after positive and negative selection. PMID:15190182

McCarty, Nami; Shinohara, Mari L.; Lu, Linrong; Cantor, Harvey



Developing an in vitro model of T cell type of large granular lymphocyte leukemia.  


We developed a strategy that can prolong in vitro growth of T cell type of large granular lymphocyte (T-LGL) leukemia cells. Primary CD8+ lymphocytes from T-LGL leukemia patients were stably transduced with the retroviral tax gene derived from human T cell leukemia virus type 2. Expression of Tax overrode replicative senescence and promoted clonal expansion of the leukemic CD8+ T cells. These cells exhibit features characteristic of leukemic LGL, including resistance to FasL-mediated apoptosis, sensitivity to the inhibitors of sphingosine-1-phosphate receptor and I?B kinases as well as expression of cytotoxic gene products such as granzyme B, perforin and IFN?. Collectively, these results indicate that this leukemia cell model can duplicate the main phenotype and pathophysiological characteristics of the clinical isolates of T-LGL leukemia. This model should be useful for investigating molecular pathogenesis of the disease and for developing new therapeutics targeting T-LGL leukemia. PMID:24183305

Ren, Tong; Yang, Jun; Broeg, Katie; Liu, Xin; Loughran, Thomas P; Cheng, Hua



Developing an in vitro model of T cell type of large granular lymphocyte leukemia  

PubMed Central

We developed a strategy that can prolong in vitro growth of T cell type of large granular lymphocyte (T-LGL) leukemia cells. Primary CD8+ lymphocytes from T-LGL leukemia patients were stably transduced with the retroviral tax gene derived from human T cell leukemia virus type 2. Expression of Tax overrode replicative senescence and promoted clonal expansion of the leukemic CD8+ T cells. These cells exhibit features characteristic of leukemic LGL, including resistance to FasL-mediated apoptosis, sensitivity to the inhibitors of sphingosine-1-phosphate receptor and I?B kinases as well as expression of cytotoxic gene products such as granzyme B, perforin and IFN?. Collectively, these results indicate that this leukemia cell model can duplicate the main phenotype and pathophysiological characteristics of the clinical isolates of T-LGL leukemia. This model should be useful for investigating molecular pathogenesis of the disease and for developing new therapeutics targeting T-LGL leukemia. PMID:24183305

Ren, Tong; Yang, Jun; Broeg, Katie; Liu, Xin; Loughran, Thomas P.; Cheng, Hua



Repertoire Development and the Control of Cytotoxic/Effector Function in Human ?? T Cells  

PubMed Central

T cells develop into two major populations distinguished by their T cell receptor (TCR) chains. Cells with the ?? TCR generally express CD4 or CD8 lineage markers and mostly fall into helper or cytotoxic/effector subsets. Cells expressing the alternate ?? TCR in humans generally do not express lineage markers, do not require MHC for antigen presentation, and recognize nonpeptidic antigens. We are interested in the dominant V?2V?2+ T cell subset in human peripheral blood and the control of effector function in this population. We review the literature on ?? T cell generation and repertoire selection, along with recent work on CD56 expression and defining a cytotoxic/effector lineage within the phosphoantigen-reactive V?2V?2 cells. A unique mechanism for MHC-independent repertoire selection is linked to the control of effector function that is vital to the role for ?? T cells in tumor surveillance. Better understanding of these mechanisms will improve our ability to exploit this population for tumor immunotherapy. PMID:20396597

Urban, Elizabeth M.; Chapoval, Andrei I.; Pauza, C. David



PD-1 is not required for natural or peripherally induced regulatory T cells: Severe autoimmunity despite normal production of regulatory T cells.  


The expression of the coinhibitor PD-1 on T cells is important for the establishment of immune homeostasis. We previously found that PD-1 is particularly critical for the control of self-tolerance during lymphopenia-induced proliferation of recent thymic emigrants (RTEs). Previous studies suggested that PD-1 modulates the generation of Treg cells, particularly peripherally induced Treg (pTreg) cells, and controls Th17 cells. However, these conclusions were derived indirectly from studies on the ligand PD-L1, and not PD-1 itself. Herein we directly tested whether T-cell PD-1 expression was needed for Treg cell generation and examined if a paucity of Treg cells or enhanced Th17 cells could explain the severe lymphopenia-potentiated autoimmunity caused by PD-1 KO RTEs. Employing the murine FoxP3(EGFP) reporter system to simultaneously monitor conversion of WT and PD-1 KO T cells to pTreg cells in the same animal, we found that PD-1 deficiency did not inhibit pTreg cell generation or lead to Th17-cell-mediated autoimmunity. Surprisingly, pTreg cell numbers were increased in PD-1 KO versus WT cell populations. Furthermore, we noted an increased conversion to pTreg cells by RTEs. Our data suggest that the primary role for PD-1 is to restrain T-cell activation/proliferation to self-Ags rather than promote generation of Treg cells. PMID:25236923

Ellestad, Kristofor K; Thangavelu, Govindarajan; Ewen, Catherine L; Boon, Louis; Anderson, Colin C



Kinetics of T-cell receptor-dependent antigen recognition determined in vivo by multi-spectral normalized epifluorescence laser scanning  

NASA Astrophysics Data System (ADS)

Detection of multiple fluorophores in conditions of low signal represents a limiting factor for the application of in vivo optical imaging techniques in immunology where fluorescent labels report for different functional characteristics. A noninvasive in vivo Multi-Spectral Normalized Epifluorescence Laser scanning (M-SNELS) method was developed for the simultaneous and quantitative detection of multiple fluorophores in low signal to noise ratios and used to follow T-cell activation and clonal expansion. Colocalized DsRed- and GFP-labeled T cells were followed in tandem during the mounting of an immune response. Spectral unmixing was used to distinguish the overlapping fluorescent emissions representative of the two distinct cell populations and longitudinal data reported the discrete pattern of antigen-driven proliferation. Retrieved values were validated both in vitro and in vivo with flow cytometry and significant correlation between all methodologies was achieved. Noninvasive M-SNELS successfully quantified two colocalized fluorescent populations and provides a valid alternative imaging approach to traditional invasive methods for detecting T cell dynamics.

Favicchio, Rosy; Zacharakis, Giannis; Oikonomaki, Katerina; Zacharopoulos, Athanasios; Mamalaki, Clio; Ripoll, Jorge



Development of an IL-15-autocrine CD8 T-cell leukemia in IL-15-transgenic mice requires the cis expression of IL-15R?.  


IL-15 has growth-promoting effects on select lymphoid subsets, including natural killer (NK) cells, NK T cells, intraepithelial lymphocytes (IELs), CD8 T cells, and ??-T cells. Constitutive expression of murine IL-15 in IL-15-transgenic mice was reported to cause T-NK leukemia. We investigated whether IL-15 expression is sufficient for leukemic transformation using a human IL-15-transgenic (IL-15Tg) mouse model. We noted that 100% of the mice observed over a 2-year period (n > 150) developed fatal expansions of CD8 T cells with NK markers, and determined that these cells expressed IL-15 receptor alpha (IL-15R?). The expression of IL-15R? on CD8 T cells appears to be required for uncontrolled aggressive lymphoproliferation, because none of the IL-15R?(-/-)-IL-15Tg mice that we followed for more than 2 years developed the fatal disease despite controlled expansion of CD8 T cells. In addition, in contrast to IL-15Tg mice, in which leukemia-like CD8 T cells expressed IL-15R? persistently, acutely activated normal CD8 T cells only transiently expressed IL-15R?. Inhibition of DNA methylation enabled sustained IL-15R? expression induced by activation. We present a scenario for IL-15Tg mice in which CD8 T cells that acquire constitutive persistent IL-15R? expression are at a selective advantage and become founder cells, outgrow other lymphocytes, and lead to the establishment of a leukemia-like condition. PMID:21304101

Sato, Noriko; Sabzevari, Helen; Fu, Song; Ju, Wei; Petrus, Michael N; Bamford, Richard N; Waldmann, Thomas A; Tagaya, Yutaka



Dietary restriction and fasting arrest B and T cell development and increase mature B and T cell numbers in bone marrow.  


Dietary restriction (DR) delays ageing and extends life span. Both long- and short-term DR, as well as short-term fasting provide robust protection against many "neuronal and surgery related damaging phenomena" such as Parkinson's disease and ischemia-reperfusion injury. The exact mechanism behind this phenomenon has not yet been elucidated. Its anti-inflammatory actions prompted us to thoroughly investigate the consequences of DR and fasting on B and T cell compartments in primary and secondary lymphoid organs of male C57Bl/6 mice. In BM we found that DR and fasting cause a decrease in the total B cell population and arrest early B cell development, while increasing the number of recirculating mature B cells. In the fasting group, a significant reduction in peripheral B cell counts was observed in both spleen and mesenteric lymph nodes (mLN). Thymopoiesis was arrested significantly at double negative DN2 stage due to fasting, whereas DR resulted in a partial arrest of thymocyte development at the DN4 stage. Mature CD3(+) T cell populations were increased in BM and decreased in both spleen and mLN. Thus, DR arrests B cell development in the BM but increases the number of recirculating mature B cells. DR also arrests maturation of T cells in thymus, resulting in depletion of mature T cells from spleen and mLN while recruiting them to the BM. The functional relevance in relation to protection against organ damage needs to be determined. PMID:24504160

Shushimita, Shushimita; de Bruijn, Marjolein J W; de Bruin, Ron W F; IJzermans, Jan N M; Hendriks, Rudi W; Dor, Frank J M F



Effect of CD4+CD25+ regulatory T cells in the development of anterior chamber-associated immune deviation  

PubMed Central

AIM To investigate whether CD4+CD25+ regulatory T (Treg) cells play a role in the development of anterior chamber-associated immune deviation (ACAID). METHODS The dynamic changes in the frequency of CD4+CD25+ T cells, CD4+CD25+ FoxP3+ T cells and CD4+CD25+ PD-1+ T cells from spleens of mice with ACAID were analyzed by flow cytometry. Foxp3 mRNA expression in purified CD4+CD25+ T cells was analyzed using real-time PCR. The suppressive effect of purified CD4+CD25+ T cells on the proliferation of CD4+CD25? T cells was evaluated by [3H] thymidine incorporation. A blocking experiment was performed to further address the role of CD4+CD25+ T cells in ACAID. The expression of IL-10 in purified CD4+CD25+ T cells was evaluated by ELISA. RESULTS Increased frequencies of CD4+CD25+ T cells, CD4+CD25+ FoxP3+ T cells and CD4+CD25+ PD-1+ T cells were observed in ACAID. The CD4+CD25+ T cells from mice with ACAID showed enhanced suppressive effect on the proliferation of CD4+CD25? T cells. Treatment of BALB/c mice with anti-CD25 antibody after injection of OVA into the anterior chamber significantly inhibited the induction of ACAID. Furthermore, purified CD4+CD25+ T cells from ACAID mice secreted IL-10. CONCLUSION Our results demonstrate that Treg cells are induced in the mice undergoing ACAID. These Treg cells may play a role in the development of ACAID. PMID:22553601

Ji, Shu-Xing; Yin, Xiao-Lei; Yang, Pei-Zeng



Bioinformatic Description of Immunotherapy Targets for Pediatric T-Cell Leukemia and the Impact of Normal Gene Sets Used for Comparison  

PubMed Central

Pediatric lymphoid leukemia has the highest cure rate of all pediatric malignancies, yet due to its prevalence, still accounts for the majority of childhood cancer deaths and requires long-term highly toxic therapy. The ability to target B-cell ALL with immunoglobulin-like binders, whether anti-CD22 antibody or anti-CD19 CAR-Ts, has impacted treatment options for some patients. The development of new ways to target B-cell antigens continues at rapid pace. T-cell ALL accounts for up to 20% of childhood leukemia but has yet to see a set of high-value immunotherapeutic targets identified. To find new targets for T-ALL immunotherapy, we employed a bioinformatic comparison to broad normal tissue arrays, hematopoietic stem cells (HSC), and mature lymphocytes, then filtered the results for transcripts encoding plasma membrane proteins. T-ALL bears a core T-cell signature and transcripts encoding TCR/CD3 components and canonical markers of T-cell development predominate, especially when comparison was made to normal tissue or HSC. However, when comparison to mature lymphocytes was also undertaken, we identified two antigens that may drive, or be associated with leukemogenesis; TALLA-1 and hedgehog interacting protein. In addition, TCR subfamilies, CD1, activation and adhesion markers, membrane-organizing molecules, and receptors linked to metabolism and inflammation were also identified. Of these, only CD52, CD37, and CD98 are currently being targeted clinically. This work provides a set of targets to be considered for future development of immunotherapies for T-ALL. PMID:24959420

Orentas, Rimas J.; Nordlund, Jessica; He, Jianbin; Sindiri, Sivasish; Mackall, Crystal; Fry, Terry J.; Khan, Javed



Bioinformatic description of immunotherapy targets for pediatric T-cell leukemia and the impact of normal gene sets used for comparison.  


Pediatric lymphoid leukemia has the highest cure rate of all pediatric malignancies, yet due to its prevalence, still accounts for the majority of childhood cancer deaths and requires long-term highly toxic therapy. The ability to target B-cell ALL with immunoglobulin-like binders, whether anti-CD22 antibody or anti-CD19 CAR-Ts, has impacted treatment options for some patients. The development of new ways to target B-cell antigens continues at rapid pace. T-cell ALL accounts for up to 20% of childhood leukemia but has yet to see a set of high-value immunotherapeutic targets identified. To find new targets for T-ALL immunotherapy, we employed a bioinformatic comparison to broad normal tissue arrays, hematopoietic stem cells (HSC), and mature lymphocytes, then filtered the results for transcripts encoding plasma membrane proteins. T-ALL bears a core T-cell signature and transcripts encoding TCR/CD3 components and canonical markers of T-cell development predominate, especially when comparison was made to normal tissue or HSC. However, when comparison to mature lymphocytes was also undertaken, we identified two antigens that may drive, or be associated with leukemogenesis; TALLA-1 and hedgehog interacting protein. In addition, TCR subfamilies, CD1, activation and adhesion markers, membrane-organizing molecules, and receptors linked to metabolism and inflammation were also identified. Of these, only CD52, CD37, and CD98 are currently being targeted clinically. This work provides a set of targets to be considered for future development of immunotherapies for T-ALL. PMID:24959420

Orentas, Rimas J; Nordlund, Jessica; He, Jianbin; Sindiri, Sivasish; Mackall, Crystal; Fry, Terry J; Khan, Javed



Critical roles of RasGRP1 for invariant natural killer T cell development  

PubMed Central

The invariant NKT (iNKT) cell lineage contains CD4+ and CD4- subsets. The mechanisms that control such subset differentiation and iNKT cell maturation in general have not been fully understood. RasGRP1, a guanine nucleotide exchange factor for T cell receptor-induced activation of the Ras-Erk1/2 pathway, is critical for conventional ?? T cell development but dispensable for generating regulatory T cells. Its role in iNKT cells has been unknown. Here we report severe decreases of iNKT cells in RasGRP1-/- mice through cell intrinsic mechanisms. In the remaining iNKT cells in RasGRP1-/- mice, there is a selective absence of the CD4+ subset. Furthermore, RasGRP1-/- iNKT cells are defective in T cell receptor induced proliferation in vitro. These observations establish that RasGRP1 is not only important for early iNKT cell development, but also for the generation/maintenance of the CD4+ iNKT cells. Our data provides genetic evidence that the CD4+ and CD4- iNKT cells are distinct sub-lineages with differential signaling requirements for their development. PMID:21957144

Shen, Shudan; Chen, Yong; Gorentla, Balachandra; Lu, Jianxin; Stone, James C.; Zhong, Xiao-Ping



PP6 Controls T Cell Development and Homeostasis by Negatively Regulating Distal TCR Signaling.  


T cell development and homeostasis are both regulated by TCR signals. Protein phosphorylation and dephosphorylation, which are catalyzed by protein kinases and phosphatases, respectively, serve as important switches controlling multiple downstream pathways triggered by TCR recognition of Ags. It has been well documented that protein tyrosine phosphatases are involved in negative regulation of proximal TCR signaling. However, how TCR signals are terminated or attenuated in the distal TCR signaling pathways is largely unknown. We investigated the function of Ser/Thr protein phosphatase (PP) 6 in TCR signaling. T cell lineage-specific ablation of PP6 in mice resulted in enhanced thymic positive and negative selection, and preferential expansion of fetal-derived, IL-17-producing V?6V?1(+) T cells. Both PP6-deficient peripheral CD4(+) helper and CD8(+) cytolytic cells could not maintain a naive state and became fast-proliferating and short-lived effector cells. PP6 deficiency led to profound hyperactivation of multiple distal TCR signaling molecules, including MAPKs, AKT, and NF-?B. Our studies demonstrate that PP6 acts as a critical negative regulator, not only controlling both ?? and ?? lineage development, but also maintaining naive T cell homeostasis by preventing their premature activation before Ag stimulation. PMID:25609840

Ye, Jian; Shi, Hao; Shen, Ye; Peng, Chao; Liu, Yan; Li, Chenyu; Deng, Kejing; Geng, Jianguo; Xu, Tian; Zhuang, Yuan; Zheng, Biao; Tao, Wufan



Gene therapy with human and mouse T-cell receptors mediates cancer regression and targets normal tissues expressing cognate antigen  

PubMed Central

Gene therapy of human cancer using genetically engineered lymphocytes is dependent on the identification of highly reactive T-cell receptors (TCRs) with antitumor activity. We immunized transgenic mice and also conducted high-throughput screening of human lymphocytes to generate TCRs highly reactive to melanoma/melanocyte antigens. Genes encoding these TCRs were engineered into retroviral vectors and used to transduce autologous peripheral lymphocytes administered to 36 patients with metastatic melanoma. Transduced patient lymphocytes were CD45RA? and CD45RO+ after ex vivo expansion. After infusion, the persisting cells displayed a CD45RA+ and CD45RO? phenotype. Gene-engineered cells persisted at high levels in the blood of all patients 1 month after treatment, responding patients with higher ex vivo antitumor reactivity than nonresponders. Objective cancer regressions were seen in 30% and 19% of patients who received the human or mouse TCR, respectively. However, patients exhibited destruction of normal melanocytes in the skin, eye, and ear, and sometimes required local steroid administration to treat uveitis and hearing loss. Thus, T cells expressing highly reactive TCRs mediate cancer regression in humans and target rare cognate–antigen-containing cells throughout the body, a finding with important implications for the gene therapy of cancer. This trial was registered at as NCI-07-C-0174 and NCI-07-C-0175. PMID:19451549

Johnson, Laura A.; Morgan, Richard A.; Dudley, Mark E.; Cassard, Lydie; Yang, James C.; Hughes, Marybeth S.; Kammula, Udai S.; Royal, Richard E.; Sherry, Richard M.; Wunderlich, John R.; Lee, Chyi-Chia R.; Restifo, Nicholas P.; Schwarz, Susan L.; Cogdill, Alexandria P.; Bishop, Rachel J.; Kim, Hung; Brewer, Carmen C.; Rudy, Susan F.; VanWaes, Carter; Davis, Jeremy L.; Mathur, Aarti; Ripley, Robert T.; Nathan, Debbie A.; Laurencot, Carolyn M.



Dietary Zinc Deficiency in Rodents: Effects on T-Cell Development, Maturation and Phenotypes  

PubMed Central

Zinc deficiency is one of the leading risk factors for developing disease and yet we do not have a clear understanding of the mechanisms behind the increased susceptibility to infection. This review will examine the interrelationships among the hypothalamus-pituitary-adrenal stress axis, p56lck, and T-cell maturation in both zinc deficiency and responses during zinc repletion. We will highlight differences between the adult mouse model (wasting malnutrition) and growing rat model (stunting malnutrition) of dietary zinc deficiency and discuss the use of various controls to separate out the effects of zinc deficiency from the associated malnutrition. Elevated serum corticosterone in both zinc deficient and pair-fed rats does not support the hypothesis that zinc deficiency per se leads to corticosterone-induced apoptosis and lymphopenia. In fact, the zinc deficient rat does not have lymphopenia. Thymocytes from zinc deficient mice and rats have elevated levels of p56lck, a signalling protein with a zinc clasp structure, but this does not appear to affect thymocyte maturation. However, post-thymic T-cell maturation appears to be altered based on the lower proportion of splenic late thymic emigrants in zinc deficient rats. Fewer new T-cells in the periphery could adversely affect the T-cell repertoire and contribute to immunodeficiency in zinc deficiency. PMID:22822446

Blewett, Heather J.; Taylor, Carla G.



CD8+ T Cell-Mediated Immunity during Trypanosoma cruzi Infection: A Path for Vaccine Development?  

PubMed Central

MHC-restricted CD8+ T cells are important during infection with the intracellular protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. Experimental studies performed in the past 25 years have elucidated a number of features related to the immune response mediated by these T cells, which are important for establishing the parasite/host equilibrium leading to chronic infection. CD8+ T cells are specific for highly immunodominant antigens expressed by members of the trans-sialidase family. After infection, their activation is delayed, and the cells display a high proliferative activity associated with high apoptotic rates. Although they participate in parasite control and elimination, they are unable to clear the infection due to their low fitness, allowing the parasite to establish the chronic phase when these cells then play an active role in the induction of heart immunopathology. Vaccination with a number of subunit recombinant vaccines aimed at eliciting specific CD8+ T cells can reverse this path, thereby generating a productive immune response that will lead to the control of infection, reduction of symptoms, and reduction of disease transmission. Due to these attributes, activation of CD8+ T lymphocytes may constitute a path for the development of a veterinarian or human vaccine. PMID:25104879

dos Santos Virgilio, Fernando; Pontes, Camila; Dominguez, Mariana Ribeiro; Ersching, Jonatan; Rodrigues, Mauricio Martins; Vasconcelos, José Ronnie



Identification of Human T Cell Antigens for the Development of Vaccines Against Mycobacterium Tuberculosis  

PubMed Central

Development of a subunit vaccine for Mycobacterium tuberculosis (Mtb) depends on the identification of antigens that induce appropriate T cell responses. Using bioinformatics, we selected a panel of 94 Mtb genes based on criteria which included growth in macrophages, up- or down-regulation under hypoxic conditions, secretion, membrane association, or because they were members of the PE/PPE or EsX families. Recombinant proteins encoded by these genes were evaluated for IFN-? recall responses using PBMC from healthy subjects previously exposed to Mtb. From this screen, dominant human T-cell antigens were identified and 49 of these proteins, formulated in CpG, were evaluated as vaccine candidates in a mouse model of tuberculosis (TB). Eighteen of the individual antigens conferred partial protection against challenge with virulent Mtb. A combination of three of these antigens further increased protection against Mtb to levels comparable to those achieved with BCG vaccination. Vaccine candidates that led to reduction in lung bacterial burden following challenge induced pluripotent CD4 and CD8 T cells, including TH1 cell responses characterized by elevated levels of antigen-specific IgG2c, IFN-? and TNF. Priority vaccine antigens elicited pluripotent CD4 and CD8 T responses in PPD+ donor PBMC. This study identified numerous novel human T cell antigens suitable to be included in subunit vaccines against TB. PMID:19017986

Bertholet, Sylvie; Ireton, Gregory C; Kahn, Maria; Guderian, Jeffrey; Mohamath, Raodoh; Stride, Nicole; Laughlin, Elsa M.; Baldwin, Susan L.; Vedvick, Thomas S.; Coler, Rhea N.; Reed, Steven G.



Regulation of the transcriptional program by DNA methylation during human ?? T-cell development.  


Thymocyte differentiation is a complex process involving well-defined sequential developmental stages that ultimately result in the generation of mature T-cells. In this study, we analyzed DNA methylation and gene expression profiles at successive human thymus developmental stages. Gain and loss of methylation occurred during thymocyte differentiation, but DNA demethylation was much more frequent than de novo methylation and more strongly correlated with gene expression. These changes took place in CpG-poor regions and were closely associated with T-cell differentiation and TCR function. Up to 88 genes that encode transcriptional regulators, some of whose functions in T-cell development are as yet unknown, were differentially methylated during differentiation. Interestingly, no reversion of accumulated DNA methylation changes was observed as differentiation progressed, except in a very small subset of key genes (RAG1, RAG2, CD8A, PTCRA, etc.), indicating that methylation changes are mostly unique and irreversible events. Our study explores the contribution of DNA methylation to T-cell lymphopoiesis and provides a fine-scale map of differentially methylated regions associated with gene expression changes. These can lay the molecular foundations for a better interpretation of the regulatory networks driving human thymopoiesis. PMID:25539926

Rodriguez, Ramon M; Suarez-Alvarez, Beatriz; Mosén-Ansorena, David; García-Peydró, Marina; Fuentes, Patricia; García-León, María J; Gonzalez-Lahera, Aintzane; Macias-Camara, Nuria; Toribio, María L; Aransay, Ana M; Lopez-Larrea, Carlos



Interaction of soybean agglutinin with leukemic T-cells and its use for their in vitro separation from normal lymphocytes by lectin-affinity chromatography.  


A procedure for separation of leukemic T-cells from normal lymphocytes, using lectin-affinity column chromatography, is described. CNBr-activated Sepharose 6MB was used as a non-mobile phase. The gel was covalently coupled with soybean agglutinin (SBA), then served as an affinity probe for fractionation of mixture of normal lymphocytes and leukemic cells. Leukemic cell lines, derived from acute lymphoblastic leukemia (Jurkat, MOLT-4, RPMI-8402), were tested. The elution of normal lymphocytes was carried out by PBS(-). The leukemic T-cells, interacting with SBA, were removed by N-acetyl-D-galactosamine or low-concentration acetic acid. The type and viability of the separated cell fractions were analyzed by flow cytometry and fluorescent microscopy, using adequate fluorescent antibodies. The interaction of leukemic T-cells with free SBA, as well as with SBA-conjugated Sepharose beads, was examined fluorimetrically and visualized by fluorescent microscopy, using FITC-SBA as a marker. The rate of cell elution on SBA-affinity column decreased in order: normal > leukemic T-cells. Both normal lymphocytes and leukemic T-cells were removed in a mixture from SBA-free Sepharose 6MB by PBS(-) and were not fractionated discretely. The leukemic T-cells specifically interacted with SBA as well as with SBA-affinity adsorbent. In contrast, the normal lymphocytes did not interact with free SBA as well as with SBA-conjugated Sepharose beads in the concentrations applied. The method potentially combines a discrete cell fractionation with manifestation of a specific target cytotoxicity of SBA against leukemic T-cells, without any influence on normal lymphocytes. PMID:12833389

Bakalova, R; Ohba, H



APCs expressing high levels of programmed death ligand 2 sustain the development of CD4 T cell memory.  


The role APCs play in the transition of T cells from effector to memory remains largely undefined. This is likely due to the low frequency at which long-lived T cells arise, which hinders analysis of the events involved in memory development. In this study, we used TCR transgenic T cells to increase the frequency of long-lived T cells and developed a transfer model suitable for defining the contribution of APCs to the development of CD4 T cell memory. Accordingly, naive TCR transgenic T cells were stimulated in vitro with Ag presented by different types of APCs and transferred into MHC class II-deficient mice for parking, and the hosts were later analyzed for long-lived T cell frequency or challenged with suboptimal dose of Ag, and the long-lived cells-driven memory responses were measured. The findings indicate that B cells and CD8alpha(+) dendritic cells sustained elevated frequencies of long-lived T cells that yielded rapid and robust memory responses upon rechallenge with suboptimal dose of Ag. Furthermore, both types of APCs had significant programmed death (PD) ligand 2 expression prior to Ag stimulation, which was maintained at a high level during presentation of Ag to T cells. Blockade of PD ligand 2 interaction with its receptor PD-1 nullified the development of memory responses. These previously unrecognized findings suggest that targeting specific APCs for Ag presentation during vaccination could prove effective against microbial infections. PMID:20709947

Ellis, Jason S; Guloglu, F Betul; Tartar, Danielle M; Hoeman, Christine M; Haymaker, Cara L; Cascio, Jason A; Wan, Xiaoxiao; Dhakal, Mermagya; VanMorlan, Amie; Yahng, Seung-Hi; Zaghouani, Habib



Colitis-associated cancer: the role of T cells in tumor development  

Microsoft Academic Search

Chronic inflammation severely increases the risk for cancer development as seen in patients with inflammatory bowel disease\\u000a (IBD). Although the exact mechanisms of inflammation-associated tumor development remain to be shown, a role for the adaptive\\u000a immune system has been implicated in colitis-associated cancer (CAC). In fact, CD4+ effector T cells, which promote chronic\\u000a inflammation in IBD, create a tumor convenient

Maximilian J. Waldner; Markus F. Neurath



Primate lentiviral Nef proteins deregulate T-cell development by multiple mechanisms  

PubMed Central

Background A nef gene is present in all primate lentiviral genomes and is important for high viral loads and progression to AIDS in human or experimental macaque hosts of HIV or SIV, respectively. In these hosts, infection of the thymus results in a decreased output of naive T cells that may contribute to the development of immunodeficiency. We have previously shown that HIV-1 subtype B Nef proteins can block human T-cell development. However, the underlying mechanism(s) and the conservation of this Nef function between different groups of HIV and SIV remained to be determined. Results We investigated whether reduction of thymic output is a conserved function of highly divergent lentiviral Nef proteins including those from both types of human immunodeficiency viruses (HIV-1 and HIV-2), their direct simian counterparts (SIVcpz, SIVgor and SIVsmm, respectively), and some additional SIV strains. We found that expression of most of these nef alleles in thymocyte progenitors impaired T-cell development and reduced thymic output. For HIV-1 Nef, binding to active p21 protein (Cdc42/Rac)-activated kinase (PAK2) was a major determinant of this function. In contrast, selective disruption of PAK2 binding did not eliminate the effect on T-cell development of SIVmac239 Nef, as was shown by expressing mutants in a newly discovered PAK2 activating structural motif (PASM) constituted by residues I117, H121, T218 and Y221, as well as previously described mutants. Rather, down-modulation of cell surface CD3 was sufficient for reduced thymic output by SIVmac Nef, while other functions of SIV Nefs contributed. Conclusions Our results indicate that primate lentiviral Nef proteins impair development of thymocyte precursors into T cells in multiple ways. The interaction of HIV-1 Nef with active PAK2 by HIV-1 seem to be most detrimental, and downregulation of CD3 by HIV-2 and most SIV Nef proteins sufficient for reduced thymic output. Since the reduction of thymic output by Nef is a conserved property of divergent lentiviruses, it is likely to be relevant for peripheral T-cell depletion in poorly adapted primate lentiviral infections. PMID:24237970



Models of Self-Peptide Sampling by Developing T Cells Identify Candidate Mechanisms of Thymic Selection  

PubMed Central

Conventional and regulatory T cells develop in the thymus where they are exposed to samples of self-peptide MHC (pMHC) ligands. This probabilistic process selects for cells within a range of responsiveness that allows the detection of foreign antigen without excessive responses to self. Regulatory T cells are thought to lie at the higher end of the spectrum of acceptable self-reactivity and play a crucial role in the control of autoimmunity and tolerance to innocuous antigens. While many studies have elucidated key elements influencing lineage commitment, we still lack a full understanding of how thymocytes integrate signals obtained by sampling self-peptides to make fate decisions. To address this problem, we apply stochastic models of signal integration by T cells to data from a study quantifying the development of the two lineages using controllable levels of agonist peptide in the thymus. We find two models are able to explain the observations; one in which T cells continually re-assess fate decisions on the basis of multiple summed proximal signals from TCR-pMHC interactions; and another in which TCR sensitivity is modulated over time, such that contact with the same pMHC ligand may lead to divergent outcomes at different stages of development. Neither model requires that T and T are differentially susceptible to deletion or that the two lineages need qualitatively different signals for development, as have been proposed. We find additional support for the variable-sensitivity model, which is able to explain apparently paradoxical observations regarding the effect of partial and strong agonists on T and T development. PMID:23935465

Bains, Iren; van Santen, Hisse M.; Seddon, Benedict; Yates, Andrew J.



Thymic development of autoreactive T cells in NOD mice is regulated in an age-dependent manner1  

PubMed Central

Inefficient thymic negative selection of self-specific T cells is associated with several autoimmune diseases, including type 1 diabetes (T1D). The factors that influence the efficacy of thymic negative selection, and the kinetics of thymic output of autoreactive T cells remain ill-defined. We investigated thymic production of ? cell-specific T cells using a thymus transplantation model. Thymi from different aged NOD mice representing distinct stages of T1D, were implanted into NOD.scid recipients and the diabetogenicity of the resulting T cell pool examined. Strikingly, the development of diabetes-inducing ? cell-specific CD4+ and CD8+ T cells was regulated in an age-dependent manner. NOD.scid recipients of newborn NOD thymi developed diabetes. However, recipients of thymi from 7 and 10 d-old NOD donor mice remained diabetes-free, and exhibited a progressive decline in islet infiltration and ? cell-specific CD4+ and CD8+ T cells. A similar temporal decrease in autoimmune infiltration was detected in some but not all tissues of recipient mice implanted with thymi from NOD mice lacking expression of the autoimmune regulator transcription factor, which develop multi-organ T cell-mediated autoimmunity. In contrast, recipients of 10 d or older thymi lacked diabetogenic T cells but developed severe colitis marked by increased effector T cells reactive to intestinal microbiota. These results demonstrate that thymic development of autoreactive T cells is limited to a narrow time-window, and occurs in a reciprocal manner compared to colonic microbiota-responsive T cells in NOD mice. PMID:24198282

He, Qiuming; Morillon, Y. Maurice; Spidale, Nicholas A.; Kroger, Charles J.; Liu, Bo; Sartor, R. Balfour; Wang, Bo; Tisch, Roland



A Quantitative Increase in Regulatory T Cells Controls Development of Vitiligo  

PubMed Central

T cell cytolytic activity targeting epidermal melanocyte is shown to cause progressive depigmentation and autoimmune vitiligo. Using the recently developed transgenic mice h3TA2 that carry T cell with a HLA-A2 restricted human tyrosinase reactive TCR and develop spontaneous vitiligo from an early age, we addressed the mechanism regulating autoimmune vitiligo. Depigmentation was significantly impaired only in IFN-? knockout h3TA2 mice but not in TNF-? or perforin knockout h3TA2 mouse strains, confirming a central role for IFN-? in vitiligo development. Additionally, the regulatory T cells (Treg) were relatively abundant in h3TA2-IFN-??/? mice, and depletion of Treg employing anti-CD25 antibody fully restored the depigmentation phenotype in h3TA2-IFN-??/? mice mediated in part through upregulation of pro-inflammatory cytokines as IL-17and IL-22. Further therapeutic potential of Treg abundance in preventing progressive depigmentation was evaluated by adoptively transferring purified Treg or using rapamycin. Both adoptive transfer of Treg and rapamycin induced lasting remission of vitiligo in mice treated at the onset of disease, or in mice with established disease. This leads us to conclude that reduced regulatory responses are pivotal to the development of vitiligo in disease-prone mice, and that a quantitative increase in the Treg population may be therapeutic for vitiligo patients with active disease. PMID:24366614

Chatterjee, Shilpak; Eby, Jonathan; Al-Khami, Amir A.; Soloshchenko, Myroslawa; Kang, Hee-Kap; Kaur, Navtej; Naga, Osama; Murali, Anuradha; Nishimura, Michael I.; Le Poole, I. Caroline; Mehrotra, Shikhar



T-cell receptor gamma delta-expressing intraepithelial lymphocytes are present in normal and chronically inflamed human gingiva.  

PubMed Central

The phenotypic profile of leucocytes in diseased and normal gingival tissue was studied in situ and in isolated gingival mononuclear cell (GMC) preparations. T-cell receptor (TcR)gamma delta + cells showed preferential localization to epithelium, both in normal and inflamed gingiva, and were present in crevicular as well as oral epithelium. In normal gingiva > or = 30% of the isolated leucocytes expressed TcR gamma delta, of which the majority were CD4- CD8-, and expressed CD45RA. The proportion of TcR gamma delta + cells in GMC from periodontitis tissue varied between 2 and 32%. In contrast to normal gingiva the majority of TcR gamma delta + cells in diseased tissue were CD8+ and expressed CD45RO. Thus expression of the CD8 antigen on gingival TcR gamma delta + cells is probably a consequence of immune activation. Numerous Langerhans' cells and keratinocytes expressing the major histocompatibility complex (MHC) class I-like antigen, CD1, were present within normal and inflamed gingival epithelium in close proximity to the TcR gamma delta + cells. Most CD1a+ cells were scattered within oral epithelium. CD1c+ cells were localized close to the basal layer of crevicular epithelium. No CD1b+ cells were found. TcR alpha beta + cells, CD4+ and B cells were restricted to lamina propria of periodontitis lesions. The presence of intraepithelial TcR gamma delta + cells in normal gingiva suggests that they constitute the 'first line of defence' against the potentially harmful microflora in the oral cavity. Induction of CD8 and CD45RO antigens on TcR gamma delta + cells in periodontitis tissue indicate that they play a significant role in the disease. CD1 molecules on Langerhans' cells and keratinocytes may be the restriction elements for the CD8+ TcR gamma delta + cells. Images Figure 1 Figure 2 Figure 3 PMID:7685315

Lundqvist, C; Hammarström, M L



C1q regulation of dendritic cell development from monocytes with distinct cytokine production and T cell stimulation.  


The causative association of complement C1q deficiency with systemic lupus erythematosus (SLE), which inevitably involves the breakdown of tolerance, remains poorly explained. Its non-hepatic, macrophage and dendritic cell (DC) origin may be highly relevant. In tissues, C1q is produced by DCs and macrophages which deposits around these cells and we ask whether this pericellular form of C1q regulates DC development from monocytes. DCs cultured on immobilized C1q (C1q-DCs) show similar MHC, CD40, CD80, CD86, CD83 and CCR7 expression as normal DCs, but these cells exhibit increased phagocytosis of apoptotic cells and elevated IL-10 but reduced IL-12 and IL-23 production. Intracellularly, C1q-DCs exhibit increased ERK, p38 and p70S6 kinase activity. By mixed leukocyte reaction, C1q-DCs show reduced Th1 and Th17 induction from allogeneic CD4(+) T cells. LPS and IFN?, which cause normal DCs to induce increased CD25 expression on CD4(+) T cells, attenuate C1q-DC induction of CD25. These imply that the DC pericellular C1q may induce tolerogenic properties in developing DCs. PMID:21429584

Teh, Boon King; Yeo, Joo Guan; Chern, Lai Min; Lu, Jinhua



A Critical Role for Dnmt1 and DNA Methylation in T Cell Development, Function, and Survival  

Microsoft Academic Search

The role of DNA methylation and of the maintenance DNA methyltransferase Dnmt1 in the epigenetic regulation of developmental stage- and cell lineage-specific gene expression in vivo is uncertain. This is addressed here through the generation of mice in which Dnmt1 was inactivated by Cre\\/loxP-mediated deletion at sequential stages of T cell development. Deletion of Dnmt1 in early double-negative thymocytes led

Peggy P. Lee; David R. Fitzpatrick; Caroline Beard; Heidi K. Jessup; Sophie Lehar; Karen W. Makar; Mercedes Pérez-Melgosa; Marianne T. Sweetser; Mark S. Schlissel; Suzanne Nguyen; Sara R. Cherry; Jeff H. Tsai; Sean M. Tucker; William M. Weaver; Anne Kelso; Rudolf Jaenisch; Christopher B. Wilson



Development of T cell lymphoma in HTLV-1 bZIP factor and Tax double transgenic mice.  


Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type 1 (HTLV-1). ATL cells possess a CD4+ CD25+ phenotype, similar to that of regulatory T cells (Tregs). Tax has been reported to play a crucial role in the leukemogenesis of HTLV-1. The HTLV-1 bZIP factor (HBZ), which is encoded by the minus strand of the viral genomic RNA, is expressed in all ATL cases and induces neoplastic and inflammatory disease in vivo. To test whether HBZ and Tax are both required for T cell malignancy, we generated HBZ/Tax double transgenic mice in which HBZ and Tax are expressed exclusively in CD4+ T cells. Survival was much reduced in HBZ/Tax double-transgenic mice compared with wild type littermates. Transgenic expression of HBZ and Tax induced skin lesions and T-cell lymphoma in mice, resembling diseases observed in HTLV-1 infected individuals. However, Tax single transgenic mice did not develop major health problems. In addition, memory CD4+ T cells and Foxp3+ Treg cells counts were increased in HBZ/Tax double transgenic mice, and their proliferation was enhanced. There was very little difference between HBZ single and HBZ/Tax double transgenic mice. Taken together, these results show that HBZ, in addition to Tax, plays a critical role in T-cell lymphoma arising from HTLV-1 infection. PMID:24818712

Zhao, Tiejun; Satou, Yorifumi; Matsuoka, Masao



Fetal Regulatory T Cells and Peripheral Immune Tolerance in utero: Implications for Development and Disease  

PubMed Central

The developing fetus must actively learn to tolerate benign antigens, or suffer the consequences of broken tolerance. Tolerance of self-antigens prevents development of autoimmune diseases, and is achieved by both deletion of autoreactive T cell clones in the thymus (central tolerance) and by the suppressive influence of CD4+CD25+FoxP3+ regulatory T cells (Tregs) in the periphery. Fetal CD4+ T cells have a strong predisposition to differentiate into tolerogenic Tregs that actively promote self-tolerance, as well as tolerance to non-inherited antigens on chimeric maternal cells that reside in most fetal tissues. As the fetus nears birth, a crucial transition must occur between the tolerogenic fetal immune system and a more defensive adult-type immune system that is able to combat pathogens. This paper will review the unique tolerogenic nature of the human fetal immune system and will examine evidence for a novel model of fetal immune development: the layered immune system hypothesis. PMID:23432802

Burt, Trevor D.



Heme Exporter FLVCR Is Required for T Cell Development and Peripheral Survival.  


All aerobic cells and organisms must synthesize heme from the amino acid glycine and the tricarboxylic acid cycle intermediate succinyl CoA for incorporation into hemoproteins, such as the cytochromes needed for oxidative phosphorylation. Most studies on heme regulation have been done in erythroid cells or hepatocytes; however, much less is known about heme metabolism in other cell types. The feline leukemia virus subgroup C receptor (FLVCR) is a 12-transmembrane domain surface protein that exports heme from cells, and it was shown to be required for erythroid development. In this article, we show that deletion of Flvcr in murine hematopoietic precursors caused a complete block in ?? T cell development at the CD4(+)CD8(+) double-positive stage, although other lymphoid lineages were not affected. Moreover, FLVCR was required for the proliferation and survival of peripheral CD4(+) and CD8(+) T cells. These studies identify a novel and unexpected role for FLVCR, a major facilitator superfamily metabolite transporter, in T cell development and suggest that heme metabolism is particularly important in the T lineage. PMID:25582857

Philip, Mary; Funkhouser, Scott A; Chiu, Edison Y; Phelps, Susan R; Delrow, Jeffrey J; Cox, James; Fink, Pamela J; Abkowitz, Janis L



Blockade of T-cell costimulation prevents development of experimental chronic renal allograft rejection.  

PubMed Central

Blocking CD28-B7 T-cell costimulation by systemic administration of CTLA4Ig, a fusion protein which binds B7 molecules on the surface of antigen-presenting cells, prevents rejection and induces tolerance in experimental acute allograft rejection models. We tested the effect of CTLA4Ig therapy on the process of chronic renal allograft rejection using an established experimental transplantation model. F344 kidneys were transplanted orthotopically into bilaterally nephrectomized LEW recipients. Control animals received low dose cyclosporine for 10 days posttransplantation. Administration of a single injection of CTLA4Ig on day 2 posttransplant alone or in addition to the low dose cyclosporine protocol resulted in improvement of long-term graft survival as compared with controls. More importantly, control recipients which received cyclosporine only developed progressive proteinuria by 8-12 weeks, and morphological evidence of chronic rejection by 16-24 weeks, including widespread transplant arteriosclerosis and focal and segmental glomerulosclerosis, while animals treated with CTLA4Ig alone or in addition to cyclosporine did not. Competitive reverse transcriptase-PCR and immunohistological analysis of allografts at 8, 16, and 24 weeks showed attenuation of lymphocyte and macrophage infiltration and activation in the CTLA4Ig-treated animals, as compared with cyclosporine-alone treated controls. These data confirm that early blockade of the CD28-B7 T-cell costimulatory pathway prevents later development and evolution of chronic renal allograft rejection. Our results indicate that T-cell recognition of alloantigen is a central event in initiating the process of chronic rejection, and that strategies targeted at blocking T-cell costimulation may prove to be a valuable clinical approach to preventing development of the process. Images Fig. 3 PMID:8901600

Azuma, H; Chandraker, A; Nadeau, K; Hancock, W W; Carpenter, C B; Tilney, N L; Sayegh, M H



78 FR 69429 - Prospective Grant of Exclusive License: The Development of Modified T-cells for the Treatment of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...License: The Development of Modified T-cells for the Treatment of Multiple Myeloma AGENCY...Chimeric Antigen Receptors Targeting B-cell Maturation Antigen'' [HHS Ref. E-040-2012...receptor (CAR)-expressing human T-cells directed against B-cell Maturation...



Generation of Functional Thymic Epithelium from Human Embryonic Stem Cells that Supports Host T Cell Development  

PubMed Central

SUMMARY Inducing immune tolerance to prevent rejection is a key step toward successful engraftment of stem-cell-derived tissue in a clinical setting. Using human pluripotent stem cells to generate thymic epithelial cells (TECs) capable of supporting T cell development represents a promising approach to reach this goal; however, progress toward generating functional TECs has been limited. Here, we describe a robust in vitro method to direct differentiation of human embryonic stem cells (hESCs) into thymic epithelial progenitors (TEPs) by precise regulation of TGF?, BMP4, RA, Wnt, Shh, and FGF signaling. The hESC-derived TEPs further mature into functional TECs that support T cell development upon transplantation into thymus-deficient mice. Importantly, the engrafted TEPs produce T cells capable of in vitro proliferation as well as in vivo immune responses. Thus, hESC-derived TEP grafts may have broad applications for enhancing engraftment in cell-based therapies as well as restoring age-and stress-related thymic decline. PMID:23684540

Parent, Audrey V.; Russ, Holger A.; Khan, Imran S.; LaFlam, Taylor N.; Metzger, Todd C.; Anderson, Mark S.; Hebrok, Matthias



The cytoplasmic domain of CD4 promotes the development of CD4 lineage T cells  

PubMed Central

Thymocytes must bind major histocompatibility complex (MHC) proteins on thymic epithelial cells in order to mature into either CD8+ cytotoxic T cells or CD4+ helper T cells. Thymic precursors express both CD8 and CD4, and it has been suggested that the intracellular signals generated by CD8 or CD4 binding to class I or II MHC, respectively, might influence the fate of uncommitted cells. Here we test the notion that intracellular signaling by CD4 directs the development of thymocytes to a CD4 lineage. A hybrid protein consisting of the CD8 extracellular and transmembrane domains and the cytoplasmic domain of CD4 (CD884) should bind class I MHC but deliver a CD4 intracellular signal. We find that expression of a hybrid CD884 protein in thymocytes of transgenic mice leads to the development of large numbers of class I MHC-specific, CD4 lineage T cells. We discuss these results in terms of current models for CD4 and CD8 lineage commitment. PMID:8642277



Design and Development of Therapies using Chimeric Antigen Receptor-Expressing T cells  

PubMed Central

Summary Investigators developed chimeric antigen receptors (CARs) for expression on T cells more than 25 years ago. When the CAR is derived from an antibody, the resultant cell should combine the desirable targeting features of an antibody (e.g. lack of requirement for major histocompatibility complex recognition, ability to recognize non-protein antigens) with the persistence, trafficking and effector functions of a T-cell. This article describes how the past two decades have seen a crescendo of research which has now begun to translate these potential benefits into effective treatments for patients with cancer. We describe the basic design of CARs, describe how antigenic targets are selected, and the initial clinical experience with CART cells. Our review then describes our own and other investigators’ work aimed at improving the function of CARs and reviews the clinical studies in hematological and solid malignancies that are beginning to exploit these approaches. Finally, we show the value of adding additional engineering features to CAR-T cells, irrespective of their target, to render them better suited to function in the tumor environment, and discuss how the safety of these heavily modified cells may be maintained. PMID:24329793

Dotti, Gianpietro; Gottschalk, Stephen; Savoldo, Barbara; Brenner, Malcolm K



Control of early stages in invariant natural killer T-cell development  

PubMed Central

Natural killer T (NKT) cells develop in the thymus from the same precursors as conventional CD4+ and CD8+?? T cells, CD4+ CD8+ double-positive cells. In contrast to conventional ??T cells, which are selected by MHC–peptide complexes presented by thymic epithelial cells, invariant NKT cells are selected by lipid antigens presented by the non-polymorphic, MHC I-like molecule CD1d, present on the surface of other double-positive thymocytes, and require additional signals from the signalling lymphocytic–activation molecule (SLAM) family of receptors. In this review, we provide a discussion of recent findings that have modified our understanding of the NKT cell developmental programme, with an emphasis on events that affect the early stages of this process. This includes factors that control double-positive thymocyte lifespan, and therefore the ability to generate the canonical V? rearrangements that characterize this lineage, as well as the signal transduction pathways engaged downstream of the T-cell receptor and SLAM molecules. PMID:21718314

Hu, Taishan; Gimferrer, Idoia; Alberola-Ila, José



Early effector T cells producing significant IFN-gamma develop into memory.  


Currently, transition of T cells from effector to memory is believed to occur as a consequence of exposure to residual suboptimal Ag found in lymphoid tissues at the waning end of the effector phase and microbial clearance. This led to the interpretation that memory arises from slightly activated late effectors producing reduced amounts of IFN-gamma. In this study, we show that CD4 T cells from the early stage of the effector phase in which both the Ag and activation are optimal also transit to memory. Moreover, early effector T cells that have undergone four divisions expressed significant IL-7R, produced IFN-gamma, and yielded rapid and robust memory responses. Cells that divided three times that had marginal IL-7R expression and no IFN-gamma raised base level homeostatic memory, whereas those that have undergone only two divisions and produced IFN-gamma yielded conditioned memory despite low IL-7R expression. Thus, highly activated early effectors generated under short exposure to optimal Ag in vivo develop into memory, and such transition is dependent on a significant production of the cell's signature cytokine, IFN-gamma. PMID:18097018

Bell, J Jeremiah; Ellis, Jason S; Guloglu, F Betul; Tartar, Danielle M; Lee, Hyun-Hee; Divekar, Rohit D; Jain, Renu; Yu, Ping; Hoeman, Christine M; Zaghouani, Habib



Impaired survival of peripheral T cells, disrupted NK/NKT cell development, and liver failure in mice lacking Gimap5  

PubMed Central

The loss of Gimap5 (GTPase of the immune-associated protein 5) gene function is the underlying cause of lymphopenia and autoimmune diabetes in the BioBreeding (BB) rat. The in vivo function of murine gimap5 is largely unknown. We show that selective gene ablation of the mouse gimap5 gene impairs the final intrathymic maturation of CD8 and CD4 T cells and compromises the survival of postthymic CD4 and CD8 cells, replicating findings in the BB rat model. In addition, gimap5 deficiency imposes a block of natural killer (NK)- and NKT-cell differentiation. Development of NK/NKT cells is restored on transfer of gimap5?/? bone marrow into a wild-type environment. Mice lacking gimap5 have a median survival of 15 weeks, exhibit chronic hepatic hematopoiesis, and in later stages show pronounced hepatocyte apoptosis, leading to liver failure. This pathology persists in a Rag2-deficient background in the absence of mature B, T, or NK cells and cannot be adoptively transferred by transplanting gimap5?/? bone marrow into wild-type recipients. We conclude that mouse gimap5 is necessary for the survival of peripheral T cells, NK/NKT-cell development, and the maintenance of normal liver function. These functions involve cell-intrinsic as well as cell-extrinsic mechanisms. PMID:18796632

Schulteis, Ryan D.; Chu, Haiyan; Dai, Xuezhi; Chen, Yuhong; Edwards, Brandon; Haribhai, Dipica; Williams, Calvin B.; Malarkannan, Subramaniam; Hessner, Martin J.; Glisic-Milosavljevic, Sanja; Jana, Srikanta; Kerschen, Edward J.; Ghosh, Soumitra; Wang, Demin; Kwitek, Anne E.; Lernmark, Ake; Gorski, Jack



Helios-positive functional regulatory T cells are decreased in decidua of miscarriage cases with normal fetal chromosomal content.  


Regulatory (Treg) T cells play essential roles in the maintenance of allogeneic pregnancy in mice and humans. Recent data show that Foxp3 expression occurs in both immuno-suppressive Treg and -nonsuppressive effector T (Teff) cells upon activation in humans. Samstein et al. (2012) reported that inducible Treg (iTreg) cells enforce maternal-fetal tolerance in placental mammals. Therefore, we should reanalyze which types of Treg cell play an important role in the maintenance of allogeneic pregnancy. In this study, we studied the frequencies of naïve Treg cells, effector Treg cells, Foxp3(+) Teff cells, Helios(+) naturally occurring Treg (nTreg) cells, and Helios(-) iTreg cells using flow cytometry. The frequencies of effector Treg cells and Foxp3(+) Teff cells among CD4(+)Foxp3(+) cells in the decidua of miscarriage cases with a normal embryo karyotype (n=8) were significantly lower (P=0.0105) and significantly higher (P=0.0258) than those in normally progressing pregnancies (n=11), respectively. However, these frequencies in miscarriages with an abnormal embryo karyotype (n=15) were similar to those in normally progressing pregnancies. The frequencies of these cell populations in the three groups were unchanged in peripheral blood; on the other hand, most of the effector Treg cells in the decidua were Helios(+) nTreg cells and these frequencies were significantly higher than those in peripheral blood, while those among effector Treg and naïve Treg cells in the decidua and peripheral blood were similar among the three groups. These data suggest that decreased Helios(+) effector nTreg might play an important role in the maintenance of pregnancy in humans. PMID:25453751

Inada, Kumiko; Shima, Tomoko; Ito, Mika; Ushijima, Akemi; Saito, Shigeru



Ionizing radiation and autoimmunity: Induction of autoimmune disease in mice by high dose fractionated total lymphoid irradiation and its prevention by inoculating normal T cells  

SciTech Connect

Ionizing radiation can functionally alter the immune system and break self-tolerance. High dose (42.5 Gy), fractionated (2.5 Gy 17 times) total lymphoid irradiation (TLI) on mice caused various organ-specific autoimmune diseases, such as gastritis, thyroiditis, and orchitis, depending on the radiation dosages, the extent of lymphoid irradiation, and the genetic background of the mouse strains. Radiation-induced tissue damage is not the primary cause of the autoimmune disease because irradiation of the target organs alone failed to elicit the autoimmunity and shielding of the organs from irradiation was unable to prevent it. In contrast, irradiation of both the thymus and the peripheral lymphoid organs/tissues was required for efficient induction of autoimmune disease by TLI. TLI eliminated the majority of mature thymocytes and the peripheral T cells for 1 mo, and inoculation of spleen cell, thymocyte, or bone marrow cell suspensions (prepared from syngeneic nonirradiated mice) within 2 wk after TLI effectively prevented the autoimmune development. Depletion of T cells from the inocula abrogated the preventive activity. CD4[sup +] T cells mediated the autoimmune prevention but CD8[sup +] T cells did not. CD4[sup +] T cells also appeared to mediate the TLI-induced autoimmune disease because CD4[sup +] T cells from disease-bearing TLI mice adoptively transferred the autoimmune disease to syngeneic naive mice. Taken together, these results indicate that high dose, fractionated ionizing radiation on the lymphoid organs/tissues can cause autoimmune disease by affecting the T cell immune system, rather than the target self-Ags, presumably by altering T cell-dependent control of self-reactive T cells. 62 refs., 9 figs., 2 tabs.

Sakaguchi, N.; Sakaguchi, S. (Stanford Univ. School of Medicine, CA (United States) Scripps Research Institute, La Jolla, CA (United States) PRESTO, JRDC, Institute of Phical and Chemical Research, Tsukuba, Ibaraki (Japan)); Miyai, K. (Univ. of California, San Diego, LA Jolla, CA (United States))



Development of Tumor-Reactive T Cells After Nonmyeloablative Allogeneic Hematopoietic Stem Cell Transplant for Chronic Lymphocytic Leukemia  

PubMed Central

Purpose Allogeneic NM-HSCT can result in durable remission of chronic lymphocytic leukemia (CLL). It is thought that the efficacy of NM-HSCT is mediated by recognition of tumor cells by T cells in the donor stem cell graft. We evaluated the development of cytotoxic T lymphocytes (CTL) specific for CLL after NM-HSCT to determine if their presence correlated with antitumor efficacy. Experimental Design Peripheral blood mononuclear cells obtained from twelve transplant recipients at intervals after NM-HSCT were stimulated in vitro with CLL cells. Polyclonal T cell lines and CD8+ T cell clones were derived from these cultures and evaluated for lysis of donor and recipient target cells including CLL. The presence and specificity of responses was correlated with clinical outcomes. Results Eight of the 12 patients achieved remission or a major antitumor response and all eight developed CD8+ and CD4+ T cells specific for antigens expressed by CLL. A clonal analysis of the CD8+ T cell response identified T cells specific for multiple minor histocompatibility (H) antigens expressed on CLL in six of the responding patients. A significant fraction of the CD8+ T cell response in some patients was also directed against non-shared tumor-specific antigens. By contrast, CLL-reactive T cells were not detected in the four patients who had persistent CLL after NM-HSCT, despite the development of GVHD. Conclusions The development of a diverse T cell response specific for minor H and tumor-associated antigens expressed by CLL predicts an effective GVL response after NM-HSCT. PMID:19567591

Nishida, Tetsuya; Hudecek, Michael; Kostic, Ana; Bleakley, Marie; Warren, Edus H.; Maloney, David; Storb, Rainer; Riddell, Stanley R.



A genome-wide regulatory network identifies key transcription factors for memory CD8[superscript +] T-cell development  

E-print Network

Memory CD8[superscript +] T-cell development is defined by the expression of a specific set of memory signature genes. Despite recent progress, many components of the transcriptional control of memory CD8[superscript +] ...

Hu, Guangan


Dissecting the effects of endogenous brain IL-2 and normal versus autoreactive T lymphocytes on microglial responsiveness and T cell trafficking in response to axonal injury.  


IL-2 is essential for T-helper regulatory (Treg) cell function and self-tolerance, and dysregulation of both endogenous brain and peripheral IL-2 gene expression may have important implications for neuronal injury and repair. We used an experimental approach combining mouse congenic breeding and immune reconstitution to test the hypothesis that the response of motoneurons to injury is modulated by the combined effects of IL2-mediated processes in the brain that modulate its endogenous neuroimmunological milieu, and IL2-mediated processes in the peripheral immune system that regulate T cell function (i.e., normal versus autoreactive Treg-deficient T cells). This experimental strategy enabled us to test our hypothesis by disentangling the effect of normal versus autoreactive T lymphocytes from the effect of endogenous brain IL-2 on microglial responsiveness (microglial phagocytic clusters normally associated with dead motoneurons and MHC2(+) activated microglia) and T cell trafficking, using the facial nerve axotomy model of injury. The results demonstrate that the loss of both brain and peripheral IL-2 had an additive effect on numbers of microglial phagocytic clusters at day 14 following injury, whereas the autoreactive status of peripheral T cells was the primary factor that determined the degree to which T cells entered the injured brain and contributed to increased microglial phagocytic clusters. Changes in activated MHC2(+) microglial in the injured FMN were associated with loss of endogenous brain IL-2 and/or peripheral IL-2. This model may provide greater understanding of the mechanisms involved in determining if T cells entering the injured central nervous system (CNS) have damaging or proregenerative effects. PMID:22922129

Huang, Zhi; Meola, Danielle; Petitto, John M



Dissecting the Effects of Endogenous Brain IL-2 and Normal Versus Autoreactive T Lymphocytes on Microglial Responsivness and T Cell Trafficking in Response to Axonal Injury  

PubMed Central

IL-2 is essential for T-helper regulatory (Treg) cell function and self-tolerance, and dysregulation of both endogenous brain and peripheral IL-2 gene expression may have important implications for neuronal injury and repair. We used an experimental approach combining mouse congenic breeding and immune reconstitution to test the hypothesis that the response of facial motoneurons to axotomy injury is modulated by the combined effects of IL2-mediated processes in the brain that modulate it’s endogenous neuroimmunological milieu, and IL2-mediated processes in the peripheral immune system that regulate T cell function (i.e., normal vs. autoreactive Treg-deficient T cells). This experimental strategy enabled us test our hypothesis by disentangling the effect of normal versus autoreactive T lymphocytes from the effect of endogenous brain IL-2 on microglial responsivness (microglial phagocytic clusters normally associated with dead motoneurons and MHC2+ activated microglia) and T cell trafficking, using the facial nerve axotomy model of injury. The results demonstrate that the loss of both brain and peripheral IL-2 had an additive effect on numbers of microglial phagocytic clusters at day 14 following injury, whereas the autoreactive status of peripheral T cells was the primary factor that determined the degree to which T cells entered the injured brain and contributed to increased microglial phagocytic clusters. Changes in activated MHC2+ microglial in the injured FMN were associated with loss of endogenous brain IL-2 and/or peripheral IL-2. This model may provide greater understanding of the mechanisms involved in determining if T cells entering the injured central nervous system (CNS) have damaging or proregenerative effects. PMID:22922129

Huang, Zhi; Meola, Danielle; Petitto, John M.



T Cell Factor-1 Controls the Lifetime of CD4+ CD8+ Thymocytes In Vivo and Distal T Cell Receptor ?-Chain Rearrangement Required for NKT Cell Development  

PubMed Central

Natural killer T (NKT) cells are a component of innate and adaptive immune systems implicated in immune, autoimmune responses and in the control of obesity and cancer. NKT cells develop from common CD4+ CD8+ double positive (DP) thymocyte precursors after the rearrangement and expression of T cell receptor (TCR) V?14-J?18 gene. Temporal regulation and late appearance of V?14-J?18 rearrangement in immature DP thymocytes has been demonstrated. However, the precise control of lifetime of DP thymocytes in vivo that enables distal rearrangements remains incompletely defined. Here we demonstrate that T cell factor (TCF)-1, encoded by the Tcf7 gene, is critical for the extended lifetime of DP thymocytes. TCF-1-deficient DP thymocytes fail to undergo TCR V?14-J?18 rearrangement and produce significantly fewer NKT cells. Ectopic expression of Bcl-xL permits V?14-J?18 rearrangement and rescues NKT cell development. We report that TCF-1 regulates expression of ROR?t, which regulates DP thymocyte survival by controlling expression of Bcl-xL. We posit that TCF-1 along with its cofactors controls the lifetime of DP thymocytes in vivo. PMID:25536344

Sen, Jyoti Misra



Polysialic acid governs T-cell development by regulating progenitor access to the thymus.  


Although the polysialyltransferase ST8Sia IV is expressed in both primary and secondary human lymphoid organs, its product, polysialic acid (polySia), has been largely overlooked by immunologists. In contrast, polySia expression and function in the nervous system has been well characterized. In this context, polySia modulates cellular adhesion, migration, cytokine response, and contact-dependent differentiation. Provocatively, these same processes are vital components of immune development and function. We previously established that mouse multipotent hematopoietic progenitors use ST8Sia IV to express polySia on their cell surfaces. Here, we demonstrate that, relative to wild-type controls, ST8Sia IV(-/-) mice have a 30% reduction in total thymocytes and a concomitant deficiency in the earliest thymocyte precursors. T-cell progenitors originate in the bone marrow and are mobilized to the blood at regular intervals by unknown signals. We performed in vivo reconstitution experiments in which ST8Sia IV(-/-) progenitors competed with wild-type cells to repopulate depleted or deficient immune subsets. Progenitors lacking polySi exhibited a specific defect in T-cell development because of an inability to access the thymus. This phenotype probably reflects a decreased capacity of the ST8Sia IV(-/-) progenitors to escape from the bone marrow niche. Collectively, these results provide evidence that polySia is involved in hematopoietic development. PMID:19587240

Drake, Penelope M; Stock, Christina M; Nathan, Jay K; Gip, Phung; Golden, Kevin P K; Weinhold, Birgit; Gerardy-Schahn, Rita; Bertozzi, Carolyn R



Notch-induced T cell development requires phosphoinositide-dependent kinase 1.  


Phosphoinositide-dependent kinase l (PDK1) phosphorylates and activates multiple AGC serine kinases, including protein kinase B (PKB), p70Ribosomal S6 kinase (S6K) and p90Ribosomal S6 kinase (RSK). PDK1 is required for thymocyte differentiation and proliferation, and herein, we explore the molecular basis for these essential functions of PDK1 in T lymphocyte development. A key finding is that PDK1 is required for the expression of key nutrient receptors in T cell progenitors: CD71 the transferrin receptor and CD98 a subunit of L-amino acid transporters. PDK1 is also essential for Notch-mediated trophic and proliferative responses in thymocytes. A PDK1 mutant PDK1 L155E, which supports activation of PKB but no other AGC kinases, can restore CD71 and CD98 expression in pre-T cells and restore thymocyte differentiation. However, PDK1 L155E is insufficient for thymocyte proliferation. The role of PDK1 in thymus development thus extends beyond its ability to regulate PKB. In addition, PDK1 phosphorylation of AGC kinases such as S6K and RSK is also necessary for thymocyte development. PMID:17599070

Kelly, April P; Finlay, David K; Hinton, Heather J; Clarke, Rosie G; Fiorini, Emma; Radtke, Freddy; Cantrell, Doreen A



Core binding factors are necessary for natural killer cell development and cooperate with Notch signaling during T-cell specification  

PubMed Central

CBF? is the non-DNA binding subunit of the core binding factors (CBFs). Mice with reduced CBF? levels display profound, early defects in T-cell but not B-cell development. Here we show that CBF? is also required at very early stages of natural killer (NK)–cell development. We also demonstrate that T-cell development aborts during specification, as the expression of Gata3 and Tcf7, which encode key regulators of T lineage specification, is substantially reduced, as are functional thymic progenitors. Constitutively active Notch or IL-7 signaling cannot restore T-cell expansion or differentiation of CBF? insufficient cells, nor can overexpression of Runx1 or CBF? overcome a lack of Notch signaling. Therefore, the ability of the prethymic cell to respond appropriately to Notch is dependent on CBF?, and both signals converge to activate the T-cell developmental program. PMID:18390836

Guo, Yalin; Maillard, Ivan; Chakraborti, Sankhamala; Rothenberg, Ellen V.



Nonclassical MHC class I-dependent invariant T cells are evolutionarily conserved and prominent from early development in amphibians  

PubMed Central

Human and murine MHC nonclassical class Ib-restricted invariant T (iT) cell subsets, such as invariant natural killer T cells (iNKT) and mucosal-associated invariant T cells, have specialized functions early in immune responses, especially in modulating subsequent adaptive immune responses. Here, we characterize a prominent iT population in the amphibian Xenopus laevis and show the requirement of the class Ib molecule, Xenopus nonclassical gene 10, in its differentiation and function. Using Xenopus nonclassical gene 10 tetramers and RNAi loss of function by transgenesis, we identified a large class Ib-dependent CD8?/CD4? iT subset in unmanipulated frogs and tadpoles. This population is critical for antiviral immunity during early larval stages when classical MHC class Ia function is suboptimal. Furthermore, in young tadpoles with low class Ia expression, deep sequencing revealed additional preponderant invariant T cell receptor (TCR)? rearrangements, implying other iT cell subsets and a predominant selection process mediated by other class Ib molecules. The restriction and requirement of class Ib molecules for development and antiviral immunity of a mammalian iNKT or mucosal-associated invariant T cell counterpart in the amphibian Xenopus show the importance of iT cells in the emergence and evolution of the adaptive immune system. PMID:23940320

Edholm, Eva-Stina; Albertorio Saez, Liz-Marie; Gill, Ann L.; Gill, Steven R.; Grayfer, Leon; Haynes, Nikesha; Myers, Jason R.; Robert, Jacques



Targeted inactivation of the COP9 signalosome impairs multiple stages of T cell development.  


Genetic programs promoting cell cycle progression, DNA repair, and survival are coordinately induced in developing T cells and require rapid turnover of effector molecules. As the COP9 signalosome (CSN) has been placed at the crossroads of these programs in lower organisms, we addressed its role by conditionally deleting CSN5/JAB1, its catalytic subunit, in developing thymocytes. CSN5/JAB1(del/del) thymocytes show defective S phase progression and massive apoptosis at the double-negative (DN) 4-double-positive (DP) transition stage, which is paralleled by altered turnover of selected CSN-controlled substrates, including p53, IkappaB-alpha, and beta-catenin. Combined dysregulation of the p53 and NF-kappaB pathways affects thymocyte survival by altering the mRNA and protein levels of selected Bcl-2 family members. Genetic complementation analysis performed on p53(-/-), Bcl-xL/Bcl-2A1, or T cell receptor transgenic backgrounds indicates that CSN5/JAB1 acts at distinct developmental stages to coordinate proliferation, survival, and positive selection of thymocytes by controlling the induction of defined genetic programs acting downstream of CSN-regulated transcription factors. PMID:18268034

Panattoni, Martina; Sanvito, Francesca; Basso, Veronica; Doglioni, Claudio; Casorati, Giulia; Montini, Eugenio; Bender, Jeffrey R; Mondino, Anna; Pardi, Ruggero



Targeted inactivation of the COP9 signalosome impairs multiple stagesof T cell development  

PubMed Central

Genetic programs promoting cell cycle progression, DNA repair, and survival are coordinately induced in developing T cells and require rapid turnover of effector molecules. As the COP9 signalosome (CSN) has been placed at the crossroads of these programs in lower organisms, we addressed its role by conditionally deleting CSN5/JAB1, its catalytic subunit, in developing thymocytes. CSN5/JAB1del/del thymocytes show defective S phase progression and massive apoptosis at the double-negative (DN) 4–double-positive (DP) transition stage, which is paralleled by altered turnover of selected CSN-controlled substrates, including p53, I?B-?, and ?-catenin. Combined dysregulation of the p53 and NF-?B pathways affects thymocyte survival by altering the mRNA and protein levels of selected Bcl-2 family members. Genetic complementation analysis performed on p53?/?, Bcl-xL/Bcl-2A1, or T cell receptor transgenic backgrounds indicates that CSN5/JAB1 acts at distinct developmental stages to coordinate proliferation, survival, and positive selection of thymocytes by controlling the induction of defined genetic programs acting downstream of CSN-regulated transcription factors. PMID:18268034

Panattoni, Martina; Sanvito, Francesca; Basso, Veronica; Doglioni, Claudio; Casorati, Giulia; Montini, Eugenio; Bender, Jeffrey R.; Mondino, Anna; Pardi, Ruggero



CD4+ T cell expression of MyD88 is essential for normal resolution of Chlamydia muridarum genital tract infection1  

PubMed Central

Resolution of Chlamydia genital tract infection is delayed in the absence of MyD88. In these studies, we first used bone marrow chimeras to demonstrate a requirement for MyD88 expression by hematopoietic cells in the presence of a wild-type epithelium. Using mixed bone marrow chimeras we then determined that MyD88 expression was specifically required in the adaptive immune compartment. Furthermore, adoptive transfer experiments revealed that CD4+ T cell expression of MyD88 was necessary for normal resolution of genital tract infection. This requirement was associated with a reduced ability of MyD88?/? CD4+ T cells to accumulate in the draining lymph nodes and genital tract when exposed to the same inflammatory milieu as wild-type CD4+ T cells. We also demonstrated that the impaired infection control we observed in the absence of MyD88 could not be recapitulated by deficiencies in TLR or IL-1R signaling. In vitro, we detected an increased frequency of apoptotic MyD88?/? CD4+ T cells upon activation in the absence of exogenous ligands for receptors upstream of MyD88. These data reveal an intrinsic requirement for MyD88 in CD4+ T cells during Chlamydia infection and indicate that the importance of MyD88 extends beyond innate immune responses by directly influencing adaptive immunity. PMID:24038087

Frazer, Lauren C.; Sullivan, Jeanne E.; Zurenski, Matthew A.; Mintus, Margaret; Tomasak, Tammy E.; Prantner, Daniel; Nagarajan, Uma M.; Darville, Toni



Annual Vaccination against Influenza Virus Hampers Development of Virus-Specific CD8+ T Cell Immunity in Children?  

PubMed Central

Infection with seasonal influenza A viruses induces immunity to potentially pandemic influenza A viruses of other subtypes (heterosubtypic immunity). We recently demonstrated that vaccination against seasonal influenza prevented the induction of heterosubtypic immunity against influenza A/H5N1 virus induced by infection with seasonal influenza in animal models, which correlated with the absence of virus-specific CD8+ T cell responses. Annual vaccination of all healthy children against influenza has been recommended, but the impact of vaccination on the development of the virus-specific CD8+ T cell immunity in children is currently unknown. Here we compared the virus-specific CD8+ T cell immunity in children vaccinated annually with that in unvaccinated children. In the present study, we compared influenza A virus-specific cellular and humoral responses of unvaccinated healthy control children with those of children with cystic fibrosis (CF) who were vaccinated annually. Similar virus-specific CD4+ T cell and antibody responses were observed, while an age-dependent increase of the virus-specific CD8+ T cell response that was absent in vaccinated CF children was observed in unvaccinated healthy control children. Our results indicate that annual influenza vaccination is effective against seasonal influenza but hampers the development of virus-specific CD8+ T cell responses. The consequences of these findings are discussed in the light of the development of protective immunity to seasonal and future pandemic influenza viruses. PMID:21880755

Bodewes, Rogier; Fraaij, Pieter L. A.; Geelhoed-Mieras, Martina M.; van Baalen, Carel A.; Tiddens, Harm A. W. M.; van Rossum, Annemarie M. C.; van der Klis, Fiona R.; Fouchier, Ron A. M.; Osterhaus, Albert D. M. E.; Rimmelzwaan, Guus F.



Zebrafish Mutants with Disrupted Early T cell and Thymus Development Identified in Early Pressure Screen1  

PubMed Central

Generation of mature T lymphocytes requires an intact hematopoietic stem cell compartment and functional thymic epithelium. We used the zebrafish (Danio rerio) to isolate mutations that affect the earliest steps in T lymphopoiesis and thymic organogenesis. Here we describe the results of a genetic screen in which gynogenetic diploid offspring from heterozygous females were analyzed by whole mount in situ hybridization for the expression of rag-1. In order to assess immediately if a global defect in hematopoiesis resulted in the mutant phenotype, ?-embryonic globin expression was simultaneously assayed for multilineage defects. In this report we present the results obtained with this strategy and show representative mutant phenotypes affecting early steps in T cell development and/or thymic epithelial cell development. We discuss the advantage of this strategy and the general usefulness of the zebrafish as a model system for vertebrate lymphopoiesis and thymic organogenesis. PMID:18729230

Trede, Nikolaus S.; Ota, Tatsuya; Kawasaki, Hirohide; Paw, Barry H.; Katz, Tammisty; Demarest, Bradley; Hutchinson, Sarah; Zhou, Yi; Hersey, Candace; Zapata, Agustin; Amemiya, Chris T; Zon, Leonard I.



microRNA regulation of T lymphocyte immunity: modulation of molecular networks responsible for T cell activation, differentiation and development  

PubMed Central

MicroRNAs (miRNA) are a class of small non-coding RNAs that constitute an essential and evolutionarily conserved mechanism for post-transcriptional gene regulation. Multiple miRNAs have been described to play key roles in T lymphocyte development, differentiation and function. In this review we highlight the current literature regarding the differential expression of miRNAs in various models of mouse and human T cell biology and emphasize mechanistic understandings of miRNA regulation of thymocyte development, T cell activation, and differentiation into effector and memory subsets. We describe the participation of miRNAs in complex regulatory circuits shaping T cell proteomes in a context-dependent manner. It is striking that some miRNAs regulate multiple processes, while others only appear in limited functional contexts. It is also evident that the expression and function of specific miRNAs can differ between mouse and human systems. Ultimately, it is not always correct to simplify the complex events of T cell biology into a model driven by only one or two master regulator miRNAs. In reality, T cell activation and differentiation involves the expression of multiple miRNAs with many mRNA targets and thus, the true extent of miRNA regulation of T cell biology is likely far more vast than currently appreciated. PMID:24099302

Podshivalova, Katie; Salomon, Daniel R.



Development and characterization of Histoplasma capsulatum-reactive murine T-cell lines and clones  

NASA Technical Reports Server (NTRS)

Several Histoplasma capsulatum-reactive murine cloned T-cell lines (TCLs) were isolated from spleens of C57BL/6 mice immunized with viable H. capsulatum yeast cells, using the methodology of Kimoto and Fathman (1980). These T-cells were characterized phenotypically as Thy-1.2(+) Lyt-1(+) L3T4(+) Lyt-2(-), that is, as the helper/inducer phenotype. The cloned T cells proliferate in response to histoplasmin and, in some cases, to heterologous fungal anigens. Upon injection of mice with the antigen, the T-cells mediate local delayed-type hypersensitivity responses and, after stimulation, release regulatory lymphokines.

Deepe, George S., Jr.; Smith, James G.; Denman, David; Bullock, Ward E.; Sonnenfeld, Gerald



Retinoic acid stimulates the cell cycle machinery in normal T cells: involvement of retinoic acid receptor-mediated IL-2 secretion.  


The mechanisms whereby vitamin A stimulates the immune system are poorly understood. In the current study, we attempted to elucidate the potential mechanisms of action of all-trans retinoic acid (atRA) on proliferation of human T lymphocytes. We found that physiological levels of atRA potently augmented T cell proliferation when added in combination with common T cell-stimulating agents. This was reflected in a time- and concentration-dependent stimulation of the cell cycle machinery. The presence of atRA led to elevated levels of cyclin D3, -E, and -A, decreased levels of p27(Kip1), increased activity of cyclin-dependent kinase 2, and enhanced phosphorylation of the retinoblastoma protein (pRB). The atRA-mediated changes in the cell cycle machinery were late events, appearing after 20 h of stimulation, indicating that the effects of atRA were indirect. atRA did not alter the expression of the high-affinity IL-2R. However, the level of IL-2 secreted by T cells was strongly enhanced by atRA. rIL-2 was able to substitute for the effects of atRA on the cell cycle machinery and on DNA synthesis, and blocking the IL-2R markedly inhibited atRA-induced cell proliferation and pRB phosphorylation. A retinoic acid receptor (RAR)-selective agonist and 9-cis-RA had the same potency as atRA on T cell proliferation and IL-2 secretion, whereas a retinoid X receptor-selective agonist had only marginal effects. Furthermore, a RAR-selective antagonist completely suppressed T cell proliferation and pRB phosphorylation induced by atRA. Taken together, these results suggest that atRA stimulates the cell cycle machinery and proliferation of normal human T cells by increasing IL-2 secretion through mechanisms involving RARs. PMID:12421932

Ertesvag, Aase; Engedal, Nikolai; Naderi, Soheil; Blomhoff, Heidi Kiil



Memory phenotype CD8+ T-cells with innate function selectively develop in the absence of active Itk  

PubMed Central

Summary T cells with a memory like phenotype and possessing innate immune function have been previously identified as CD8+CD44hi cells. These cells rapidly secrete IFN? upon stimulation with IL-12/IL-18 and are involved in innate responses to infection with Listeria monocytogenes. The signals regulating these cells are unclear. The Tec kinase Itk regulates T cell activation and we report here that a majority of the CD8+ T cells in Itk null mice have a phenotype of CD44hi similar to memory like innate T cells. These cells are observed in mice carrying an Itk mutant lacking the kinase domain, indicating that active Tec kinase signaling suppresses their presence. These cells carry preformed message for and are able to rapidly produce IFN? upon stimulation in vitro with IL-12/IL-18, and endow Itk null mice the ability to effectively respond to infection with L. monocytogenes or exposure to LPS by secretion of IFN?. Transfer of these cells rescues the ability of IFN? null mice to reduce bacterial burden following L. monocytogenes infection indicating that these cells are functional CD8+CD44hi T cells previously detected in vivo. These results indicate that active signals from Tec kinases regulate the development of memory like CD8+ T cells with innate function. PMID:17724684

Hu, Jianfang; Sahu, Nisebita; Walsh, Elizabeth; August, Avery



Quantitative and Temporal Requirements Revealed for Zap-70 Catalytic Activity During T Cell Development  

PubMed Central

The catalytic activity of Zap-70 is crucial for T cell receptor (TCR) signaling, but the quantitative and temporal requirements for its function in thymocyte development are not known. Using a chemical-genetic system to selectively and reversibly inhibit Zap-70 catalytic activity in a model of synchronized thymic selection, we showed that CD4+CD8+ thymocytes integrate multiple, transient, Zap-70-dependent signals over more than 36 h to reach a cumulative threshold for positive selection, whereas one hour of signaling was sufficient for negative selection. Titration of Zap-70 activity resulted in graded reductions in positive and negative selection but did not decrease the cumulative TCR signals integrated by positively selected OT-I cells, revealing heterogeneity, even among CD4+CD8+ thymocytes expressing identical TCRs undergoing positive selection. PMID:24908390

Au-Yeung, Byron B.; Melichar, Heather J.; Ross, Jenny O.; Cheng, Debra A.; Zikherman, Julie; Shokat, Kevan M.; Robey, Ellen A.; Weiss, Arthur



Blocked negative selection of developing T cells in mice expressing the baculovirus p35 caspase inhibitor.  

PubMed Central

Clonal deletion in the thymus by apoptosis is involved in purging the immune system of self-reactive T lymphocytes (negative selection). Cysteine proteases (caspases) belonging to the CPP32 family are activated during this process. We have produced transgenic mice expressing baculovirus p35, a broad-range caspase inhibitor. Thymocytes from p35 transgenic mice were resistant in vitro to several apoptosis-inducing agents; this resistance correlated with the inhibition of CPP32-like activity. Negative selection in vivo of thymocytes triggered by two exogenous antigens, staphylococcal enterotoxin B superantigen and an antigenic peptide in the F5 T-cell receptor transgenic model, was specifically inhibited in p35 transgenic mice. Our results provide direct evidence for caspase involvement in negative selection during thymocyte development. PMID:9878059

Izquierdo, M; Grandien, A; Criado, L M; Robles, S; Leonardo, E; Albar, J P; de Buitrago, G G; Martínez-A, C



Complementary dendritic cell-activating function of CD8+ and CD4+ T cells: helper role of CD8+ T cells in the development of T helper type 1 responses.  


Dendritic cells (DCs) activated by CD40L-expressing CD4+ T cells act as mediators of "T helper (Th)" signals for CD8+ T lymphocytes, inducing their cytotoxic function and supporting their long-term activity. Here, we show that the optimal activation of DCs, their ability to produce high levels of bioactive interleukin (IL)-12p70 and to induce Th1-type CD4+ T cells, is supported by the complementary DC-activating signals from both CD4+ and CD8+ T cells. Cord blood- or peripheral blood-isolated naive CD8+ T cells do not express CD40L, but, in contrast to naive CD4+ T cells, they are efficient producers of IFN-gamma at the earliest stages of the interaction with DCs. Naive CD8+ T cells cooperate with CD40L-expressing naive CD4+ T cells in the induction of IL-12p70 in DCs, promoting the development of primary Th1-type CD4+ T cell responses. Moreover, the recognition of major histocompatibility complex class I-presented epitopes by antigen-specific CD8+ T cells results in the TNF-alpha- and IFN-gamma-dependent increase in the activation level of DCs and in the induction of type-1 polarized mature DCs capable of producing high levels of IL-12p70 upon a subsequent CD40 ligation. The ability of class I-restricted CD8+ T cells to coactivate and polarize DCs may support the induction of Th1-type responses against class I-presented epitopes of intracellular pathogens and contact allergens, and may have therapeutical implications in cancer and chronic infections. PMID:11854360

Mailliard, Robbie B; Egawa, Shinichi; Cai, Quan; Kalinska, Anna; Bykovskaya, Svetlana N; Lotze, Michael T; Kapsenberg, Martien L; Storkus, Walter J; Kalinski, Pawel



Effector-memory T cells develop in islets and report islet pathology in type 1 diabetes.  


CD8(+) T cells are critical in human type 1 diabetes and in the NOD mouse. In this study, we elucidated the natural history of islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)-specific CD8(+) T cells in NOD diabetes using MHC-tetramer technology. IGRP206-214-specific T cells in the peripheral lymphoid tissue increased with age, and their numbers correlated with insulitis progression. IGRP206-214-specific T cells in the peripheral lymphoid tissue expressed markers of chronic Ag stimulation, and their numbers were stable after diagnosis of diabetes, consistent with their memory phenotype. IGRP206-214-specific T cells in NOD mice expand, acquire the phenotype of effector-memory T cells in the islets, and emigrate to the peripheral lymphoid tissue. Our observations suggest that enumeration of effector-memory T cells of multiple autoantigen specificities in the periphery of type 1 diabetic subjects could be a reliable reporter for progression of islet pathology. PMID:24337380

Chee, Jonathan; Ko, Hyun-Ja; Skowera, Ania; Jhala, Gaurang; Catterall, Tara; Graham, Kate L; Sutherland, Robyn M; Thomas, Helen E; Lew, Andrew M; Peakman, Mark; Kay, Thomas W H; Krishnamurthy, Balasubramanian



Human Leukemia Cell Maturation Induced by a T-Cell Lymphokine Isolated from Medium Conditioned by Normal Lymphocytes  

Microsoft Academic Search

Human myelogeneous leukemia cells in liquid culture can be induced to mature along the monocyte\\/macrophage pathway by a maturation inducer derived from the conditioned medium of activated human T lymphocytes. Serum-free conditioned medium was used for the isolation of the T-cell lymphokine. The maturation inducer was purified ≈ 6000-fold by ammonium sulfate precipitation, low-salt elution from DEAE-Sepharose CL-6B, gel filtration

Kiu Leung; Jen Wei Chiao



Changes in autoreactive T cell avidity during type 1 diabetes development  

PubMed Central

The activation threshold for antigen-specific T cell responses is dependent on the avidity of the trimolecular interaction between TCR, antigen, and MHC. We compared CD4+ T cell avidities for the diabetes-associated autoantigen glutamic acid decarboxylase 555-567 (GAD 555) among serial samples from autoantibody-positive subjects at high risk of progression to type 1 diabetes (T1D). T cells from three at-risk subjects demonstrated significant avidity increases (p<0.05 by F test) over time. This avidity shift correlated with the outgrowth of T cells expressing TCR BV 9, 15, 17 or 20 that demonstrated higher GAD 555 tetramer-binding levels compared to cells expressing other TCR BV genes. Similar analysis of autoantibody-negative, first-degree relatives and T1D patients did not demonstrate similar changes in avidity. These data implicate the outgrowth of T cells expressing higher affinity TCR in a process of antigen-specific T cell avidity maturation during the pre-clinical stage of T1D. PMID:19482555

Standifer, Nathan E.; Burwell, Emily A.; Gersuk, Vivian H.; Greenbaum, Carla J.; Nepom, Gerald T.



Pharmacological Inhibition of Glycogen Synthase Kinase 3 Regulates T Cell Development In Vitro  

PubMed Central

The development of functional T cells requires receptor-mediated transition through multiple checkpoints in the thymus. Double negative 3 (DN3) thymocytes are selected for the presence of a rearranged TCR beta chain in a process termed ?-selection which requires signalling via the pre-TCR, Notch1 and CXCL12. Signal integration by these receptors converges on core pathways including the Phosphatidylinositol–3-kinase (PI3K) pathway. Glycogen Synthase Kinase 3 (GSK3) is generally thought to be negatively regulated by the PI3K pathway but its role in ?-selection has not been characterised. Here we show that developmental progression of DN3 thymocytes is promoted following inhibition of GSK3 by the synthetic compound CHIR99021. CHIR99021 allows differentiation in the absence of pre-TCR-, Notch1- or CXCL12-mediated signalling. It antagonizes IL-7-mediated inhibition of DP thymocyte differentiation and increases IL-7-promoted cell recovery. These data indicate a potentially important role for inactivation of GSK3 during ?-selection. They might help to establish an in vitro stromal cell-free culture system of thymocyte development and offer a new platform for screening regulators of proliferation, differentiation and apoptosis. PMID:23526989

Schroeder, Jan-Hendrik; Bell, Lewis S.; Janas, Michelle L.; Turner, Martin



Regulatory T cell ablation causes acute T cell lymphopenia.  


Regulatory T (Treg) cells enforce T cell homeostasis and maintain peripheral T cell tolerance. Here we report a previously unappreciated phenomenon of acute T cell lymphopenia in secondary lymphoid organs and non-lymphoid tissues triggered by Treg cell depletion that precedes the expansion of self-reactive T cells. Lymphopenia affects both neonates and adults indicating a dominant role of Treg cells in maintaining peripheral T cell numbers regardless of the developmental stage. The lymphopenia was neither triggered by caspase-dependent apoptosis nor macrophage-mediated clearance of T cells, nor diminished survival of naïve or recently activated T cells due to paucity of IL-7. It is possible that transient lymphopenia associated with congenital or acute Treg cell deficiency may contribute to the development of T cell mediated autoimmune disorders. PMID:24466225

Moltedo, Bruno; Hemmers, Saskia; Rudensky, Alexander Y



Regulatory T Cell Ablation Causes Acute T Cell Lymphopenia  

PubMed Central

Regulatory T (Treg) cells enforce T cell homeostasis and maintain peripheral T cell tolerance. Here we report a previously unappreciated phenomenon of acute T cell lymphopenia in secondary lymphoid organs and non-lymphoid tissues triggered by Treg cell depletion that precedes the expansion of self-reactive T cells. Lymphopenia affects both neonates and adults indicating a dominant role of Treg cells in maintaining peripheral T cell numbers regardless of the developmental stage. The lymphopenia was neither triggered by caspase-dependent apoptosis nor macrophage-mediated clearance of T cells, nor diminished survival of naïve or recently activated T cells due to paucity of IL-7. It is possible that transient lymphopenia associated with congenital or acute Treg cell deficiency may contribute to the development of T cell mediated autoimmune disorders. PMID:24466225

Moltedo, Bruno; Hemmers, Saskia; Rudensky, Alexander Y.



Programmed cell death 1 inhibits inflammatory helper T-cell development through controlling the innate immune response  

PubMed Central

Programmed cell death 1 (PD-1) is an inhibitory coreceptor on immune cells and is essential for self-tolerance because mice genetically lacking PD-1 (PD-1?/?) develop spontaneous autoimmune diseases. PD-1?/? mice are also susceptible to severe experimental autoimmune encephalomyelitis (EAE), characterized by a massive production of effector/memory T cells against myelin autoantigen, the mechanism of which is not fully understood. We found that an increased primary response of PD-1?/? mice to heat-killed mycobacteria (HKMTB), an adjuvant for EAE, contributed to the enhanced production of T-helper 17 (Th17) cells. Splenocytes from HKMTB-immunized, lymphocyte-deficient PD-1?/? recombination activating gene (RAG)2?/? mice were found to drive antigen-specific Th17 cell differentiation more efficiently than splenocytes from HKMTB-immunized PD-1+/+ RAG2?/? mice. This result suggested PD-1’s involvement in the regulation of innate immune responses. Mice reconstituted with PD-1?/? RAG2?/? bone marrow and PD-1+/+ CD4+ T cells developed more severe EAE compared with the ones reconstituted with PD-1+/+ RAG2?/? bone marrow and PD-1+/+ CD4+ T cells. We found that upon recognition of HKMTB, CD11b+ macrophages from PD-1?/? mice produced very high levels of IL-6, which helped promote naive CD4+ T-cell differentiation into IL-17–producing cells. We propose a model in which PD-1 negatively regulates antimycobacterial responses by suppressing innate immune cells, which in turn prevents autoreactive T-cell priming and differentiation to inflammatory effector T cells. PMID:24043779

Rui, Yuxiang; Honjo, Tasuku; Chikuma, Shunsuke



Major histocompatibility complex class I-restricted T cells are required for all but the end stages of diabetes development in nonobese diabetic mice and use a prevalent T cell receptor ? chain gene rearrangement  

PubMed Central

Nonobese diabetic (NOD) mice develop insulin-dependent diabetes mellitus due to autoimmune T lymphocyte-mediated destruction of pancreatic ? cells. Although both major histocompatibility complex class I-restricted CD8+ and class II-restricted CD4+ T cell subsets are required, the specific role each subset plays in the pathogenic process is still unclear. Here we show that class I-dependent T cells are required for all but the terminal stages of autoimmune diabetes development. To characterize the diabetogenic CD8+ T cells responsible, we isolated and propagated in vitro CD8+ T cells from the earliest insulitic lesions of NOD mice. They were cytotoxic to NOD islet cells, restricted to H-2Kd, and showed a diverse T cell receptor ? chain repertoire. In contrast, their ? chain repertoire was more restricted, with a recurrent amino acid sequence motif in the complementarity-determining region 3 loop and a prevalence of V?17 family members frequently joined to the J?42 gene segment. These results suggest that a number of the CD8+ T cells participating in the initial phase of autoimmune ? cell destruction recognize a common structural component of Kd/peptide complexes on pancreatic ? cells, possibly a single peptide. PMID:9770521

DiLorenzo, Teresa P.; Graser, Robert T.; Ono, Toshiro; Christianson, Gregory J.; Chapman, Harold D.; Roopenian, Derry C.; Nathenson, Stanley G.; Serreze, David V.



Recombinase-deficient T cell development by selective accumulation of CD3 into lipid rafts.  


The pre-T cell receptor (pre-TCR) promotes the development of thymocytes with productive rearrangement at the TCR beta chain locus by signaling in a ligand-independent fashion. The TCR beta chain associates with the invariant pre-Talpha (pTalpha) chain, which bears specific charged residues in the extracellular portion mediating pre-TCR self-oligomerization. In recombinase-deficient thymocytes, calnexin (CNX) associated with CD3 chains is inefficiently retained in the endoplasmic reticulum (ER) and weakly expressed in the plasma membrane. Deliberate cross-linking of CNX/CD3 complexes mimics pre-TCR signaling. Here, we show that, analogously to the pTalpha chain, surface CNX is palmitoylated and that CD3 prominently accumulated in lipid rafts upon cross-linking. Mutant CNX isoforms devoid of ER retention determined pre-TCR-like signaling and simulated beta selection only when stably translocating CD3 to lipid rafts. Inclusion of the palmitoylated cytoplasmic tail from the pTalpha chain in recombinant CNX strikingly improved the pre-TCR-like signaling efficiency of CNX/CD3 in rafts. This study indicates that lipid rafts in the plasma membrane represent proficient microdomains for the initiation of pre-TCR signaling, and supports the view that beta selection by oligomerized pre-TCR is implemented by the pTalpha cytoplasmic tail. PMID:18350545

Ferrera, Denise; Panigada, Maddalena; Porcellini, Simona; Grassi, Fabio



Definition of regulatory network elements for T cell development by perturbation analysis with PU.1 and GATA-3.  


PU.1 and GATA-3 are transcription factors that are required for development of T cell progenitors from the earliest stages. Neither one is a simple positive regulator for T lineage specification, however. When expressed at elevated levels at early stages of T cell development, each of these transcription factors blocks T cell development within a different, characteristic time window, with GATA-3 overexpression initially inhibiting at an earlier stage than PU.1. These perturbations are each associated with a distinct spectrum of changes in the regulation of genes needed for T cell development. Both transcription factors can interfere with expression of the Rag-1 and Rag-2 recombinases, while GATA-3 notably blocks PU.1 and IL-7Ralpha expression, and PU.1 reduces expression of HES-1 and c-Myb. A first-draft assembly of the regulatory targets of these two factors is presented as a provisional gene network. The target genes identified here provide insight into the basis of the effects of GATA-3 or PU.1 overexpression and into the regulatory changes that distinguish the developmental time windows for these effects. PMID:12027437

Anderson, Michele K; Hernandez-Hoyos, Gabriela; Dionne, Christopher J; Arias, Alexandra M; Chen, Dan; Rothenberg, Ellen V



Monocytes and T cells cooperate to favor normal and follicular lymphoma B-cell growth: role of IL-15 and CD40L signaling.  


Interleukin-15 (IL-15) has been extensively studied for its role in the survival and proliferation of NK and T cells through a unique mechanism of trans-presentation by producer cells. Conversely, whereas activated B cells have been described as IL-15-responding cells, the cellular and molecular context sustaining this effect remains unexplored. In this study, we found that, whereas human B cells could not respond to soluble IL-15, monocytes and lymphoid tissue-derived macrophages but not stromal cells efficiently trans-present IL-15 to normal B cells and cooperate with T-cell-derived CD40L to promote IL-15-dependent B-cell proliferation. Furthermore, CD40L signaling triggers a Src-independent upregulation of STAT5 expression and favors a Src-dependent phosphorylation of STAT5 in response to IL-15. In follicular lymphoma (FL), immunohistochemical studies reported a strong relationship between malignant B cells, infiltrating macrophages and T cells. We show here an overexpression of IL-15 in purified tumor-associated macrophages, and STAT5A in purified tumor B cells. Moreover, FL B cells respond to IL-15 trans-presented by monocytes/macrophages, in particular, in the presence of CD40L-mediated signaling. This cooperation between IL-15 and CD40L reinforces the importance of tumor microenvironment and unravels a mechanism of FL growth that should be considered if using IL-15 as a drug in this disease. PMID:21788945

Epron, G; Ame-Thomas, P; Le Priol, J; Pangault, C; Dulong, J; Lamy, T; Fest, T; Tarte, K



Normal growth and development  


... and development can be divided into four periods: Infancy Preschool years Middle childhood years Adolescence Immediately after ... child's age. Healthy eating habits should begin during infancy. This can help prevent diseases such as type ...


In vitro induction of non-responsiveness in cloned normal inducer T cells by antigen and purified Ia incorporated into planar membranes  

SciTech Connect

Incubation of cytochrome c-specific E/sub ..beta..//sup k/E/sub ..cap alpha..//sup k/-containing planar membranes and an antigenic peptide analogue of moth cytochrome c resulted in a specific increase in cell volume of 40-50% as measured by Coulter Counter analysis. No change in cell volume was seen in the absence of antigen, or when A/sub ..beta..//sup k/A/sub ..cap alpha..//sup k/-planar membranes were used. T cell proliferation was never detected at any time from one to eight days after incubation with E/sub ..beta..//sup k/E/sub ..cap alpha..//sup k/-membranes at a wide range of antigen concentrations. Furthermore, only trace amounts of IL-2 were detected and no increase in IL-2 receptor expression was seen. IL-3 production, however, could be detected. T cells pre-incubated for one day with E/sub ..beta..//sup k/E/sub ..cap alpha..//sup k/-membranes plus antigen became non-responsive to subsequent normal stimulation with antigen and APC. Incorporation of /sup 3/H-thymidine was reduced by more than 90% and the production of both IL-2 and IL-3 was inhibited. Non-responsiveness persisted for at least eight days after exposure to E/sub ..beta..///sup k/E/sub ..cap alpha..//sup k/-membranes plus antigen. In contrast, T cells pre-incubated under control conditions remained fully responsive. These results demonstrate the specific induction of non-responsiveness in inducer T cells by antigen and purified E/sub ..beta..//sup k/E/sub ..cap alpha..//sup k/ in planar membranes.

Quill, H.; Fox, B.; Carlson, L.; Pardoll, D.; Schwartz, R.H.



The Single Positive T Cells Found in CD3- z \\/ h 2 \\/ 2 Mice Overtly React with Self-Major Histocompatibility Complex Molecules upon Restoration of Normal Surface Density of T Cell Receptor-CD3 Complex  

Microsoft Academic Search

Summary CD3- z \\/ h -deficient mice have small thymuses containing cells that show a profound reduction in the surface levels of T cell receptors and terminate their differentiation at the CD4 1 CD8 1 stage. Rather unexpectedly, CD3 2 or very low single positive T cells accumulate over time in the spleen and lymph nodes of CD3- z \\/

Shih-Yao Lin; Laurence Ardouin; Anne Gillet; Marie Malissen; Bernard Malissen


Disruption of T cell signaling networks and development by Grb2 haploid insufficiency  

Microsoft Academic Search

The developmental processes of positive and negative selection in the thymus shape the T cell antigen receptor (TCR) repertoire and require the integration of multiple signaling networks. These networks involve the efficient assembly of macromolecular complexes and are mediated by multimodular adaptor proteins that permit the functional integration of distinct signaling molecules. We show here that decreased expression of the

Qian Gong; Alec M. Cheng; Antonina M. Akk; Jose Alberola-Ila; Guoqing Gong; Tony Pawson; Andrew C. Chan



Regulation of T Cell Development and Activation by Creatine Kinase B  

PubMed Central

Creatine kinase catalyzes the reversible transfer of the N-phosphoryl group from phosphocreatine to ADP to generate ATP and plays a key role in highly energy-demanding processes such as muscle contraction and flagellar motility; however, its role in signal transduction (which frequently involves ATP-consuming phosphorylation) and consequent cell-fate decisions remains largely unknown. Here we report that creatine kinase B was significantly up-regulated during the differentiation of double-positive thymocytes into single-positive thymocytes. Ectopic expression of creatine kinase B led to increased ATP level and enhanced phosphorylation of the TCR signaling proteins. Consequentially, transgenic expression of creatine kinase B promoted the expression of Nur77 and Bim proteins and the cell death of TCR signaled thymocyte. In addition, the activation, proliferation and cytokine secretion of T cells were also enhanced by the expression of creatine kinase B transgene. In contrast, treatment of T cells with specific creatine kinase inhibitor or creatine kinase B shRNA resulted in severely impaired T cell activation. Taken together, our results indicate that creatine kinase B plays an unexpected role in modulating TCR-mediated signaling and critically regulates thymocyte selection and T cell activation. PMID:19337362

Zhang, Yafeng; Li, Hai; Wang, Xiaoming; Gao, Xiang; Liu, Xiaolong



Rearrangement and expression of T cell antigen receptor and gamma genes during thymic development  

PubMed Central

Rearrangement and expression of the T cell antigen receptor and the gamma genes during T cell ontogeny is a regulated process; the gamma genes are rearranged and expressed first, followed by the beta and then the alpha genes. Expression of both functional alpha and beta gene RNA first occurs at day 17 of gestation, along with the expression of T3 delta chain RNA. T cell antigen receptor gene rearrangements occur primarily or exclusively in the thymus, although some gamma gene rearrangements occur outside the thymus in fetal liver cells that may be committed T cell progenitors. There is no gross difference in the extent of beta and gamma gene rearrangements in the adult thymocyte subpopulations that were analyzed, despite the fact that some of these populations cannot respond to antigen and never emigrate from the thymus. Quantitative analysis of rearrangements in total adult thymocyte DNA shows that beta gene rearrangements generally occur on both chromosomal homologs, and that rearrangements occur preferentially to the J beta 2 gene segment cluster. PMID:3487610



Antigen Presenting Cells Expressing High Levels of PD-L2 Sustain the Development of CD4-T Cell Memory1  

PubMed Central

The role APCs play in the transition of T cells from effector to memory remains largely undefined. This is likely due to the low frequency at which long-lived T cells arise which hinders analysis of the events involved in memory development. Herein, we used TCR transgenic T cells to increase the frequency of long-lived T cells and developed a transfer model suitable for defining the contribution of APCs to the development of CD4-T cell memory. Accordingly, naive TCR transgenic T cells were stimulated in vitro with Ag presented by different types of APCs, transferred into MHC class II-deficient (MHC II?/?) mice for parking, and the hosts were later analyzed for long-lived T cell frequency or challenged with suboptimal dose of Ag and the long-lived cells-driven memory responses were measured. The findings indicate that B cells and CD8?+ DCs sustained elevated frequencies of long-lived T cells which yielded rapid and robust memory responses upon re-challenge with sub-optimal dose of Ag. Furthermore, both types of APCs had significant Programmed Death Ligand 2 (PD-L2) expression prior to Ag stimulation, which was maintained at a high level during presentation of Ag to T cells. Blockade of PD-L2 interaction with its receptor Programmed Death (PD-1) nullified the development of memory responses. These previously unrecognized findings suggest that targeting specific APCs for Ag presentation during vaccination could prove effective against microbial infections. PMID:20709947

Ellis, Jason S.; Guloglu, F. Betul; Tartar, Danielle M.; Hoeman, Christine M.; Haymaker, Cara L.; Cascio, Jason A.; Wan, Xiaoxiao; Dhakal, Mermagya; VanMorlan, Amie; Yahng, Seung-Hi; Zaghouani, Habib



The SLAM-Associated Protein (SAP)/Fyn/PKC? Pathway is Required for Thymocyte-mediated CD4 T Cell Development  

PubMed Central

Summary MHC class II-expressing double positive thymocytes induce progression of CD4 T cell development, as efficiently as cortical thymic epithelial cells (cTEC). Because double positive thymocytes expressing CD1d select NKT cells, we investigated whether thymocyte-selected CD4 (T-CD4) T cells require the same signaling components as NKT cells. We therefore examined the role of SAP, Fyn, PKC?, one of the SAP binding receptors Ly108, T-bet, and IL-15R? in T-CD4 T cell development. Using bone marrow chimeras, we found that SAP, Fyn and PKC? are essential for T-CD4 T cell generation, whereas mutations in Ly108, IL-15R? or T-bet had a marginal effect. Furthermore, SAP is critical for IL-4 production by T-CD4 T cells, but the PKC? deficiency did not alter the ability of T-CD4 T cells to produce cytokines. T-bet is necessary to produce the maximum amount of IFN-? for CD4 T cells regardless of the selection pathway. We conclude that, in contrast to mainstream epithelial cell-selected CD4 T cells, the two distinct lineages of T cells selected by thymocytes, i.e. T-CD4 and NKT cells both utilize the SAP/Fyn/PKC? pathway for their development and function. PMID:18031696

Li, Wei; Sofi, M. Hanief; Rietdijk, Svend; Wang, Ninghai; Terhorst, Cox; Chang, Cheong-Hee



Numb-dependent integration of pre-TCR and p53 function in T-cell precursor development  

PubMed Central

Numb asymmetrically segregates at mitosis to control cell fate choices during development. Numb inheritance specifies progenitor over differentiated cell fates, and, paradoxically, also promotes neuronal differentiation, thus indicating that the role of Numb may change during development. Here we report that Numb nuclear localization is restricted to early thymocyte precursors, whereas timed appearance of pre-T-cell receptor (pre-TCR) and activation of protein kinase C? promote phosphorylation-dependent Numb nuclear exclusion. Notably, nuclear localization of Numb in early thymocyte precursors favors p53 nuclear stabilization, whereas pre-TCR-dependent Numb nuclear exclusion promotes the p53 downmodulation essential for further differentiation. Accordingly, the persistence of Numb in the nucleus impairs the differentiation and promotes precursor cell death. This study reveals a novel regulatory mechanism for Numb function based on its nucleus–cytosol shuttling, coupling the different roles of Numb with different stages of T-cell development. PMID:25321479

Martin-Blanco, N M; Checquolo, S; Del Gaudio, F; Palermo, R; Franciosa, G; Di Marcotullio, L; Gulino, A; Canelles, M; Screpanti, I



T-cell recognition of chemicals, protein allergens and drugs: towards the development of in vitro assays.  


Chemicals can elicit T-cell-mediated diseases such as allergic contact dermatitis and adverse drug reactions. Therefore, testing of chemicals, drugs and protein allergens for hazard identification and risk assessment is essential in regulatory toxicology. The seventh amendment of the EU Cosmetics Directive now prohibits the testing of cosmetic ingredients in mice, guinea pigs and other animal species to assess their sensitizing potential. In addition, the EU Chemicals Directive REACh requires the retesting of more than 30,000 chemicals for different toxicological endpoints, including sensitization, requiring vast numbers of animals. Therefore, alternative methods are urgently needed to eventually replace animal testing. Here, we summarize the outcome of an expert meeting in Rome on 7 November 2009 on the development of T-cell-based in vitro assays as tools in immunotoxicology to identify hazardous chemicals and drugs. In addition, we provide an overview of the development of the field over the last two decades. PMID:20717835

Martin, Stefan F; Esser, Philipp R; Schmucker, Sonja; Dietz, Lisa; Naisbitt, Dean J; Park, B Kevin; Vocanson, Marc; Nicolas, Jean-Francois; Keller, Monika; Pichler, Werner J; Peiser, Matthias; Luch, Andreas; Wanner, Reinhard; Maggi, Enrico; Cavani, Andrea; Rustemeyer, Thomas; Richter, Anne; Thierse, Hermann-Josef; Sallusto, Federica



5. T cell immunity and neuroplasticity  

PubMed Central

The proneuronal effects of T cells that impact the brain occur from both T cells trafficking into the brain, and from signals in the periphery (e.g., cytokine release and regulation). Recent data indicates that neuroimmunological changes in the brain can modify intrinsic brain processes that are involved in regulating neuroplasticity (e.g., T-cell/microglial interactions, neurotrophins, neurogenesis). We describe: 1) work from our lab and others showing that injury-induced loss of neuronal phenotype and reversal of motor neuron atrophy are associated with normal T cell immunity, and; 2) research indicating that these and other neuroimmunological processes may be generalizable to mechanisms of neuroplasticity involved in cognitive and emotional behavior. These findings are discussed in relation to our lab’s working hypothesis, that T cell immunosenesence may contribute to alterations in brain neuroplasticity related to aging. Greater understanding of the role of adaptive T cell immunity on neuroplasticity could have important clinical implications for developing novel treatment strategies for neurodegenerative diseases (e.g., Alzheimer’s) and brain injury (e.g., stroke, trauma).

Huang, Zhi; Ha, Grace K.; Petitto, John M.



Exclusive Development of T cell Neoplasms in Mice Transplanted with Bone Marrow Expressing Activated Notch Alleles  

Microsoft Academic Search

Summary Notch is a highly conserved transmembrane protein that is involved in cell fate decisions and is found in organisms ranging from Drosophila to humans. A human homologue of Notch, TAN1, was initially identified at the chromosomal breakpoint of a subset of T-cell lymphoblastic leu- kemias\\/lymphomas containing a t(7;9) chromosomal translocation; however, its role in onco- genesis has been unclear.

Warren S. Pear; Jon C. Aster; Martin L. Scott; Robert E Hasserjian; Benny Softer; Jeffrey Sklar; David Baltimore



An essential role for the transcription factor HEB in thymocyte survival, Tcra rearrangement and the development of natural killer T cells  

PubMed Central

E proteins are basic helix-loop-helix transcription factors that regulate many key aspects of lymphocyte development. Thymocytes express multiple E proteins that are thought to provide cooperative and compensatory functions crucial for T cell differentiation. Contrary to that, we report here that the E protein HEB was uniquely required at the CD4+CD8+ double-positive (DP) stage of T cell development. Thymocytes lacking HEB showed impaired survival, failed to make rearrangements of variable-? (V?) segments to distal joining-? (J?) segments in the gene encoding the T cell antigen receptor ?-chain (Tcra) and had a profound, intrinsic block in the development of invariant natural killer T cells (iNKT cells) at their earliest progenitor stage. Thus, our results show that HEB is a specific and essential factor in T cell development and in the generation of the iNKT cell lineage, defining a unique role for HEB in the regulation of lymphocyte maturation. PMID:20154672

D’Cruz, Louise M; Knell, Jamie; Fujimoto, Jessica K; Goldrath, Ananda W



HTLV-1 Propels Thymic Human T Cell Development in “Human Immune System” Rag2-/- gamma c-/- Mice  

PubMed Central

Alteration of early haematopoietic development is thought to be responsible for the onset of immature leukemias and lymphomas. We have previously demonstrated that TaxHTLV-1 interferes with ß-selection, an important checkpoint of early thymopoiesis, indicating that human T-cell leukemia virus type 1 (HTLV-1) infection has the potential to perturb thymic human ?? T-cell development. To verify that inference and to clarify the impact of HTLV-1 infection on human T-cell development, we investigated the in vivo effects of HTLV-1 infection in a “Human Immune System” (HIS) Rag2-/-?c-/- mouse model. These mice were infected with HTLV-1, at a time when the three main subpopulations of human thymocytes have been detected. In all but two inoculated mice, the HTLV-1 provirus was found integrated in thymocytes; the proviral load increased with the length of the infection period. In the HTLV-1-infected mice we observed alterations in human T-cell development, the extent of which correlated with the proviral load. Thus, in the thymus of HTLV-1-infected HIS Rag2-/-?c-/- mice, mature single-positive (SP) CD4+ and CD8+ cells were most numerous, at the expense of immature and double-positive (DP) thymocytes. These SP cells also accumulated in the spleen. Human lymphocytes from thymus and spleen were activated, as shown by the expression of CD25: this activation was correlated with the presence of tax mRNA and with increased expression of NF-kB dependent genes such as bfl-1, an anti-apoptotic gene, in thymocytes. Finally, hepato-splenomegaly, lymphadenopathy and lymphoma/thymoma, in which Tax was detected, were observed in HTLV-1-infected mice, several months after HTLV-1 infection. These results demonstrate the potential of the HIS Rag2-/-?c-/- animal model to elucidate the initial steps of the leukemogenic process induced by HTLV-1. PMID:21909275

Villaudy, Julien; Wencker, Mélanie; Gadot, Nicolas; Gillet, Nicolas A.; Scoazec, Jean-Yves; Gazzolo, Louis; Manz, Markus G.; Bangham, Charles R. M.; Dodon, Madeleine Duc



Development of ?? T cell subset responses in gnotobiotic pigs infected with human rotaviruses and colonized with probiotic lactobacilli  

Microsoft Academic Search

?? T cell responses are induced by various viral and bacterial infections. Different ?? T cells contribute to activation and regulation of the inflammatory response and to epithelial repair. How ?? T cells respond to rotavirus infection and how the colonization of probiotics influences the ?? T cell response were unknown. In this study, we evaluated by multicolor flow cytometry

Ke Wen; Guohua Li; Wei Zhang; Marli S. P. Azevedo; Linda J. Saif; Fangning Liu; Tammy Bui; Ahmed Yousef; Lijuan Yuan



The ? isoform of diacylglycerol kinase plays a predominant role in regulatory T cell development and TCR-mediated ras signaling.  


Diacylglycerol (DAG) is a critical second messenger that mediates T cell receptor (TCR)-stimulated signaling. The abundance of DAG is reduced by the diacylglycerol kinases (DGKs), which catalyze the conversion of DAG to phosphatidic acid (PA) and thus inhibit DAG-mediated signaling. In T cells, the predominant DGK isoforms are DGK? and DGK?, and deletion of the genes encoding either isoform enhances DAG-mediated signaling. We found that DGK?, but not DGK?, suppressed the development of natural regulatory T (T(reg)) cells and predominantly mediated Ras and Akt signaling downstream of the TCR. The differential functions of DGK? and DGK? were not attributable to differences in protein abundance in T cells or in their localization to the contact sites between T cells and antigen-presenting cells. RasGRP1, a key DAG-mediated activator of Ras signaling, associated to a greater extent with DGK? than with DGK?; however, in silico modeling of TCR-stimulated Ras activation suggested that a difference in RasGRP1 binding affinity was not sufficient to cause differences in the functions of each DGK isoform. Rather, the model suggested that a greater catalytic rate for DGK? than for DGK? might lead to DGK? exhibiting increased suppression of Ras-mediated signals compared to DGK?. Consistent with this notion, experimental studies demonstrated that DGK? was more effective than DGK? at catalyzing the metabolism of DAG to PA after TCR stimulation. The enhanced effective enzymatic production of PA by DGK? is therefore one possible mechanism underlying the dominant functions of DGK? in modulating T(reg) cell development. PMID:24280043

Joshi, Rohan P; Schmidt, Amanda M; Das, Jayajit; Pytel, Dariusz; Riese, Matthew J; Lester, Melissa; Diehl, J Alan; Behrens, Edward M; Kambayashi, Taku; Koretzky, Gary A



The ? Isoform of Diacylglycerol Kinase Plays a Predominant Role in Regulatory T Cell Development and TCR-Mediated Ras Signaling  

PubMed Central

Diacylglycerol (DAG) is a critical second messenger that mediates T cell receptor (TCR)–stimulated signaling. The abundance of DAG is reduced by the diacylglycerol kinases (DGKs), which catalyze the conversion of DAG to phosphatidic acid (PA) and thus inhibit DAG-mediated signaling. In T cells, the predominant DGK isoforms are DGK? and DGK?, and deletion of the genes encoding either isoform enhances DAG-mediated signaling. We found that DGK?, but not DGK?, suppressed the development of natural regulatory T (Treg) cells and predominantly mediated Ras and Akt signaling downstream of the TCR. The differential functions of DGK? and DGK? were not attributable to differences in protein abundance in T cells or in their localization to the contact sites between T cells and antigen-presenting cells. RasGRP1, a key DAG-mediated activator of Ras signaling, associated to a greater extent with DGK? than with DGK?; however, in silico modeling of TCR-stimulated Ras activation suggested that a difference in RasGRP1 binding affinity was not sufficient to cause differences in the functions of each DGK isoform. Rather, the model suggested that a greater catalytic rate for DGK? than for DGK? might lead to DGK? exhibiting increased suppression of Ras-mediated signals compared to DGK?. Consistent with this notion, experimental studies demonstrated that DGK? was more effective than DGK? at catalyzing the metabolism of DAG to PA after TCR stimulation. The enhanced effective enzymatic production of PA by DGK? is therefore one possible mechanism underlying the dominant functions of DGK? in modulating Treg cell development. PMID:24280043

Joshi, Rohan P.; Schmidt, Amanda M.; Das, Jayajit; Pytel, Dariusz; Riese, Matthew J.; Lester, Melissa; Diehl, J. Alan; Behrens, Edward M.; Kambayashi, Taku; Koretzky, Gary A.



Rational development of high-affinity T-cell receptor-like antibodies  

PubMed Central

T-cell interaction with a target cell is a key event in the adaptive immune response and primarily driven by T-cell receptor (TCR) recognition of peptide-MHC (pMHC) complexes. TCR avidity for a given pMHC is determined by number of MHC molecules, availability of coreceptors, and TCR affinity for MHC or peptide, respectively, with peptide recognition being the most important factor to confer target specificity. Here we present high-resolution crystal structures of 2 Fab antibodies in complex with the immunodominant NY-ESO-1157–165 peptide analogue (SLLMWITQV) presented by HLA-A*0201 and compare them with a TCR recognizing the same pMHC. Binding to the central methionine-tryptophan peptide motif and orientation of binding were almost identical for Fabs and TCR. As the MW “peg” dominates the contacts between Fab and peptide, we estimated the contributions of individual amino acids between the Fab and peptide to provide the rational basis for a peptide-focused second-generation, high-affinity antibody library. The final Fab candidate achieved better peptide binding by 2 light-chain mutations, giving a 20-fold affinity improvement to 2–4 nM, exceeding the affinity of the TCR by 1,000-fold. The high-affinity Fab when grafted as recombinant TCR on T cells conferred specific killing of HLA-A*0201/NY-ESO-1157–165 target cells. In summary, we prove that affinity maturation of antibodies mimicking a TCR is possible and provide a strategy for engineering high-affinity antibodies that can be used in targeting specific pMHC complexes for diagnostic and therapeutic purposes. PMID:19307587

Stewart-Jones, Guillaume; Wadle, Andreas; Hombach, Anja; Shenderov, Eugene; Held, Gerhard; Fischer, Eliane; Kleber, Sascha; Nuber, Natko; Stenner-Liewen, Frank; Bauer, Stefan; McMichael, Andrew; Knuth, Alexander; Abken, Hinrich; Hombach, Andreas A.; Cerundolo, Vincenzo; Jones, E. Yvonne; Renner, Christoph



The SLAM-associated protein signaling pathway is required for development of CD4+ T cells selected by homotypic thymocyte interaction.  


MHC class II-expressing double-positive thymocytes induce progression of CD4(+) T cell development as efficiently as cortical thymic epithelial cells do. Because double-positive thymocytes expressing CD1d select natural killer T (NKT) cells, we investigated whether thymocyte-selected CD4(+) (T-CD4) T cells require the same signaling components as NKT cells. Using bone-marrow chimeras, we found that the signaling molecules SAP, Fyn, and PKCtheta were essential for T-CD4 T cell generation, whereas mutations in the Ly108 receptor, interleukin-15 receptor alpha, or the transcription factor T-bet had a marginal effect. Furthermore, SAP was critical for IL-4 production by T-CD4 T cells, but the PKCtheta deficiency did not alter the ability of T-CD4 T cells to produce cytokines. T-bet was necessary to produce the maximum amount of IFN-gamma for CD4(+) T cells regardless of the selection pathway. Thus, in contrast to epithelial cell-selected CD4(+) T cells, the two distinct lineages of T cells selected by thymocytes--i.e., T-CD4 and NKT cells--both utilize the SAP-Fyn-PKCtheta pathway for their development and function. PMID:18031696

Li, Wei; Sofi, M Hanief; Rietdijk, Svend; Wang, Ninghai; Terhorst, Cox; Chang, Cheong-Hee



Influence of HIV and HCV on T cell antigen presentation and challenges in the development of vaccines  

PubMed Central

Some of the central challenges for developing effective vaccines against HIV and hepatitis C virus (HCV) are similar. Both infections are caused by small, highly mutable, rapidly replicating RNA viruses with the ability to establish long-term chronic pathogenic infection in human hosts. HIV has caused 60 million infections globally and HCV 180 million and both viruses may co-exist among certain populations by virtue of common blood-borne, sexual, or vertical transmission. Persistence of both pathogens is achieved by evasion of intrinsic, innate, and adaptive immune defenses but with some distinct mechanisms reflecting their differences in evolutionary history, replication characteristics, cell tropism, and visibility to mucosal versus systemic and hepatic immune responses. A potent and durable antibody and T cell response is a likely requirement of future HIV and HCV vaccines. Perhaps the single biggest difference between the two vaccine design challenges is that in HCV, a natural model of protective immunity can be found in those who resolve acute infection spontaneously. Such spontaneous resolvers exhibit durable and functional CD4+ and CD8+ T cell responses (Diepolder et al., 1995; Cooper et al., 1999; Thimme et al., 2001; Grakoui et al., 2003; Lauer et al., 2004; Schulze Zur Wiesch et al., 2012). However, frequent re-infection suggests partial or lack of protective immunity against heterologous HCV strains, possibly indicative of the degree of genetic diversity of circulating HCV genotypes and subtypes. There is no natural model of protective immunity in HIV, however, studies of “elite controllers,” or individuals who have durably suppressed levels of plasma HIV RNA without antiretroviral therapy, has provided the strongest evidence for CD8+ T cell responses in controlling viremia and limiting reservoir burden in established infection. Here we compare and contrast the specific mechanisms of immune evasion used by HIV and HCV, which subvert adaptive human leukocyte antigen (HLA)-restricted T cell immunity in natural infection, and the challenges these pose for designing effective preventative or therapeutic vaccines. PMID:25352836

John, Mina; Gaudieri, Silvana



The adoptive transfer of cultured T cells for patients with metastatic melanoma.  


T cells have been shown to be capable of rejecting a patient's tumor. Weak responses to current vaccines and the toxicity of exogenously administered cytokines limit the intensity of the T-cell response that can be actively generated in vivo. Adoptive T-cell transfer enhances an intrinsically weak immune response to cancer by activating and expanding tumor reactive T cells in vitro and manipulating the environment of the host at the time of transfer. One can frequently find tumor-reactive T cells in metastatic lesions in patients with melanoma, and expand them in vitro for readministration. When successful, this adoptive cellular immunotherapy has resulted in sustainable curative outcomes. Subsequently, the applicability of adoptive T-cell transfer has been greatly expanded by the development of methods to genetically engineer open-repertoire human T-cells to confer tumor reactivity. This re-direction of T-cell specificity can be achieved by introducing a variety of receptors that ligate tumor-associated antigens and then trigger the normal activation mechanism of T cells. Future T-cell engineering will add a new dimension by reprogramming T-cell functions for optimal tumor rejection. The antigens recognized by T cells, the techniques to procure and grow tumor reactive T cells, the conditioning of the recipient to optimize efficacy, and the results of clinical protocols are reviewed herein. PMID:23438384

Yang, James C



Gallium maltolate inhibits human cutaneous T-cell lymphoma tumor development in mice.  


Cutaneous T-cell lymphomas (CTCLs) represent a heterogeneous group of non-Hodgkin's lymphoma characterized by an accumulation of malignant CD4 T cells in the skin. The group IIIa metal salt, gallium nitrate, is known to have antineoplastic activity against B-cell lymphoma in humans, but its activity in CTCLs has not been elaborated in detail. Herein, we examined the antineoplastic efficacy of a gallium compound, gallium maltolate (GaM), in vitro and in vivo with murine models of CTCLs. GaM inhibited cell growth and induced apoptosis of cultured CTCL cells. In human CTCL xenograft models, peritumoral injection of GaM limited the growth of CTCL cells, shown by fewer tumor formations, smaller tumor sizes, and decreased neovascularization in tumor microenvironment. To identify key signaling pathways that have a role in GaM-mediated reduction of tumor growth, we analyzed inflammatory cytokines, as well as signal transduction pathways in CTCL cells treated by GaM. IFN-?-induced chemokines and IL-13 were found to be notably increased in GaM-treated CTCL cells. However, immunosuppressive cytokines, such as IL-10, were decreased with GaM treatment. Interestingly, both oxidative stress and p53 pathways were involved in GaM-induced cytotoxicity. These results warrant further investigation of GaM as a therapeutic agent for CTCLs. PMID:25371972

Wu, Xuesong; Wang, Timothy W; Lessmann, George M; Saleh, Jamal; Liu, Xiping; Chitambar, Christopher R; Hwang, Sam T



Hierarchical self-tolerance to T cell determinants within the ubiquitous nuclear self-antigen La (SS-B) permits induction of systemic autoimmunity in normal mice.  


Systemic autoimmune diseases are frequently associated with clustering of high titer autoantibody responses towards nuclear self-antigens. Little is known, however, about the extent of immune tolerance to the target nuclear antigens or the events leading to the complex autoantibody responses that are characteristic of systemic autoimmunity. To address these issues, we have examined the mouse immune response to La autoantigen (mLa) and the homologous human La antigen (hLa), which are components of the La(SS-B)/Ro(SS-A) ribonucleoprotein (RNP) complex targeted in systemic lupus erythematosus and primary Sjögren's syndrome. The findings reveal the presence of hierarchical T cell tolerance involving multiple autodeterminants within the La autoantigen expressed by normal H-2k and H-2a mice. At one end of this spectrum, there was no detectable T or B cell autoimmunity observed in mice that were immunized with the immunodominant mLa287-301 determinant, which differed by a single residue in its core sequence from the homologous but highly immunogenic human La288-302 determinant. Interestingly, the mLa287-301 peptide acted as an altered peptide ligand that specifically antagonized the activation of an hLa288-302-specific T cell hybridoma. In contrast to the tolerogenic mLa287-301 determinant, a range of autoimmune potential was identified among poorly tolerizing, subdominant self-peptides present within mouse La autoantigen. Notably, immunization of normal mice with the autologous subdominant La25-44 and La106-129 determinants resulted in limited or no detectable autoantibody response. In contrast, immunization with the subdominant mouse La13-30 determinant induced a proliferative T cell response associated with the appearance of specific autoantibodies recognizing multiple intrastructural (La) and intermolecular components (Ro) of the murine La/Ro RNP. The findings suggest how diversified autoimmunity might follow initiation of immunity to simple peptide mimics of poorly tolerogenic determinants that are present within ubiquitous self-antigens. PMID:8920873

Reynolds, P; Gordon, T P; Purcell, A W; Jackson, D C; McCluskey, J



The c-kit+ maturation pathway in mouse thymic T cell development: lineages and selection.  


Positive selection of T cells begins with TCR alpha beta lo thymic progenitors. Here, we show that the most efficient TCRlo progenitors are c-kit+ with intermediate levels of CD4 and CD8 (DPint). Positive selection of DPint TCRlo c-kit+ cells results in TCRmed CD69+ c-kit+ transitional intermediates that show increased TCRV beta frequencies to selecting superantigen (SAg) that are committed to the CD4 or CD8 pathway. The cells on the c-kit+ maturation pathway maintain Bcl-2 expression. Most DPint c-kit+ progenitors fail positive selection, and become DPhi c-kit- cells that lose Bcl-2 expression. Some DPhi c-kit blast cells can be salvaged to produce mature single-positive (SP) cells. DPint c-kit+ maturation to SP cells can occur in <12 hr in vitro on thymic stromal monolayers. PMID:8769478

Akashi, K; Weissman, I L



ERK1-Deficient Mice Show Normal T Cell Effector Function and Are Highly Susceptible to Experimental Autoimmune  

E-print Network

oligodendrocyte glycoprotein peptide 35­55 and to the prototypic foreign Ag OVA are not impaired as compared- myelitis induced with myelin oligodendrocyte glycoprotein peptide 35­55. Finally, thymocyte development to the prototypic foreign Ag OVA and the self Ag myelin oligodendrocyte glycoprotein (MOG)3 35­55 in ERK1-de


Development and Function of Invariant Natural Killer T Cells Producing TH2- and TH17-Cytokines  

PubMed Central

There is heterogeneity in invariant natural killer T (iNKT) cells based on the expression of CD4 and the IL-17 receptor B (IL-17RB), a receptor for IL-25 which is a key factor in TH2 immunity. However, the development pathway and precise function of these iNKT cell subtypes remain unknown. IL-17RB+ iNKT cells are present in the thymic CD44+/? NK1.1? population and develop normally even in the absence of IL-15, which is required for maturation and homeostasis of IL-17RB? iNKT cells producing IFN-?. These results suggest that iNKT cells contain at least two subtypes, IL-17RB+ and IL-17RB? subsets. The IL-17RB+ iNKT subtypes can be further divided into two subtypes on the basis of CD4 expression both in the thymus and in the periphery. CD4+ IL-17RB+ iNKT cells produce TH2 (IL-13), TH9 (IL-9 and IL-10), and TH17 (IL-17A and IL-22) cytokines in response to IL-25 in an E4BP4-dependent fashion, whereas CD4? IL-17RB+ iNKT cells are a retinoic acid receptor-related orphan receptor (ROR)?t+ subset producing TH17 cytokines upon stimulation with IL-23 in an E4BP4-independent fashion. These IL-17RB+ iNKT cell subtypes are abundantly present in the lung in the steady state and mediate the pathogenesis in virus-induced airway hyperreactivity (AHR). In this study we demonstrated that the IL-17RB+ iNKT cell subsets develop distinct from classical iNKT cell developmental stages in the thymus and play important roles in the pathogenesis of airway diseases. PMID:22346732

Watarai, Hiroshi; Sekine-Kondo, Etsuko; Shigeura, Tomokuni; Motomura, Yasutaka; Yasuda, Takuwa; Satoh, Rumi; Yoshida, Hisahiro; Kubo, Masato; Kawamoto, Hiroshi; Koseki, Haruhiko; Taniguchi, Masaru



Strategy escalation: an emerging paradigm for safe clinical development of T cell gene therapies.  


Gene therapy techniques are being applied to modify T cells with chimeric antigen receptors (CARs) for therapeutic ends. The versatility of this platform has spawned multiple options for their application with new permutations in strategies continually being invented, a testimony to the creative energies of many investigators. The field is rapidly expanding with immense potential for impact against diverse cancers. But this rapid expansion, like the Big Bang, comes with a somewhat chaotic evolution of its therapeutic universe that can also be dangerous, as seen by recently publicized deaths. Time-honored methods for new drug testing embodied in Dose Escalation that were suitable for traditional inert agents are now inadequate for these novel "living drugs". In the following, I propose an approach to escalating risk for patient exposures with these new immuno-gene therapy agents, termed Strategy Escalation, that accounts for the molecular and biological features of the modified cells and the methods of their administration. This proposal is offered not as a prescriptive but as a discussion framework that investigators may wish to consider in configuring their intended clinical applications. PMID:20537174

Junghans, Richard Paul



SAP Protein Dependent Natural Killer T-Like Cells Regulate the Development of CD8+ T Cells with Innate Lymphocyte Characteristics  

PubMed Central

SUMMARY CD8+ T cells are selected via low affinity interaction with MHC class I molecules on thymic epithelial cells (TECs). However, compromised T cell receptor signaling was proposed to force CD8+ T cell selection on hematopoietic cells through a SLAM-associated protein (SAP)-dependent mechanism similar to NKT cells. The outcome is an unconventional CD8+ T cell with phenotypic and functional characteristics of innate lymphocytes. Here we showed that Id3?/ ? CD8+ T cells had an innate-like phenotype and required SAP for their development. However, like conventional CD8+ T cells, Id3?/ ? CD8+ thymocytes were selected on TECs. The requirement for SAP and the innate-like phenotype was not intrinsic to Id3?/ ? CD8+ thymocytes. Rather, an expanded population of NKT-like cells induced the innate phenotype on CD8+ T cells through production of interleukin-4. Our findings reveal that accumulation of NKT-like cells promotes conventional CD8+ thymocytes to acquire innate lymphocyte characteristics. PMID:20674402

Verykokakis, Mihalis; Boos, Markus D.; Bendelac, Albert; Kee, Barbara L.



Epitope-specific CD8+ T cells play a differential pathogenic role in the development of a viral disease model for multiple sclerosis.  


Theiler's virus-induced demyelinating disease has been extensively investigated as a model for persistent viral infection and multiple sclerosis (MS). However, the role of CD8(+) T cells in the development of disease remains unclear. To assess the role of virus-specific CD8(+) T cells in the pathogenesis of demyelinating disease, a single amino acid substitution was introduced into the predominant viral epitope (VP3 from residues 159 to 166 [VP3(159-166)]) and/or a subdominant viral epitope (VP3(173-181)) of susceptible SJL/J mice by site-directed mutagenesis. The resulting variant viruses (N160V, P179A, and N160V/P179A) failed to induce CD8(+) T cell responses to the respective epitopes. Surprisingly, mice infected with N160V or N160V/P179A virus, which lacks CD8(+) T cells against VP3(159-166), did not develop demyelinating disease, in contrast to wild-type virus or P179A virus lacking VP3(173-181)-specific CD8(+) T cells. Our findings clearly show that the presence of VP3(159-166)-specific CD8(+) T cells, rather than viral persistence itself, is strongly correlated with disease development. VP3(173-181)-specific CD8(+) T cells in the central nervous system (CNS) of these virus-infected mice expressed higher levels of transforming growth factor ?, forkhead box P3, interleukin-22 (IL-22), and IL-17 mRNA but caused minimal cytotoxicity compared to that caused by VP3(159-166)-specific CD8(+) T cells. VP3(159-166)-specific CD8(+) T cells exhibited high functional avidity for gamma interferon production, whereas VP3(173-181)-specific CD8(+) T cells showed low avidity. To our knowledge, this is the first report indicating that the induction of the IL-17-producing CD8(+) T cell type is largely epitope specific and that this specificity apparently plays a differential role in the pathogenicity of virus-induced demyelinating disease. These results strongly advocate for the careful consideration of CD8(+) T cell-mediated intervention of virus-induced inflammatory diseases. PMID:23055563

Myoung, Jinjong; Kang, Hyun Seok; Hou, Wanqiu; Meng, Liping; Dal Canto, Mauro C; Kim, Byung S



Molecular Evidence for a Thymus-Independent Partial T Cell Development in a FOXN1?/? Athymic Human Fetus  

PubMed Central

The thymus is the primary organ able to support T cell ontogeny, abrogated in FOXN1?/? human athymia. Although evidence indicates that in animal models T lymphocytes may differentiate at extrathymic sites, whether this process is really thymus-independent has still to be clarified. In an athymic FOXN1?/? fetus, in which we previously described a total blockage of CD4+ and partial blockage of CD8+ cell development, we investigated whether intestine could play a role as extrathymic site of T-lymphopoiesis in humans. We document the presence of few extrathymically developed T lymphocytes and the presence in the intestine of CD3+ and CD8+, but not of CD4+ cells, a few of them exhibiting a CD45RA+ naïve phenotype. The expression of CD3??pT?, RAG1 and RAG2 transcripts in the intestine and TCR gene rearrangement was also documented, thus indicating that in humans the partial T cell ontogeny occurring at extrathymic sites is a thymus- and FOXN1-independent process. PMID:24349129

Fusco, Anna; Panico, Luigi; Gorrese, Marisa; Bianchino, Gabriella; Barone, Maria V.; Grieco, Vitina; Vitiello, Laura; D’Assante, Roberta; Romano, Rosa; Palamaro, Loredana; Scalia, Giulia; Vecchio, Luigi Del; Pignata, Claudio



Rhizoctonia Bataticola Lectin (RBL) Induces Caspase-8-Mediated Apoptosis in Human T-Cell Leukemia Cell Lines but Not in Normal CD3 and CD34 Positive Cells  

PubMed Central

We have previously demonstrated immunostimulatory activity of a fungal lectin, Rhizoctonia bataticola lectin (RBL), towards normal human peripheral blood mononuclear cells. The present study aimed to explore the anticancer activities of RBL using human leukemic T-cell lines, Molt-4, Jurkat and HuT-78. RBL exhibited significant binding (>90%) to the cell membrane that was effectively inhibited by complex glycoproteins such as mucin (97% inhibition) and asialofetuin (94% inhibition) but not simple sugars such as N-acetyl-D-galactosamine, glucose and sucrose. RBL induced a dose and time dependent inhibition of proliferation and induced cytotoxicity in the cell lines. The percentage of apoptotic cells, as determined by hypodiploidy, was 33% and 42% in Molt-4 and Jurkat cells, respectively, compared to 3.11% and 2.92% in controls. This effect was associated with a concomitant decrease in the G0/G1 population. Though initiator caspase-8 and -9 were activated upon exposure to RBL, inhibition of caspase-8 but not caspase-9 rescued cells from RBL-induced apoptosis. Mechanistic studies revealed that RBL induced cleavage of Bid, loss of mitochondrial membrane potential and activation of caspase-3. The expression of the anti-apoptotic proteins Bcl-2 and Bcl-X was down regulated without altering the expression of pro-apoptotic proteins- Bad and Bax. In contrast to leukemic cells, RBL did not induce apoptosis in normal PBMC, isolated CD3+ve cells and undifferentiated CD34+ve hematopoietic stem and progenitor cells (HSPCs). The findings highlight the differential effects of RBL on transformed and normal hematopoietic cells and suggest that RBL may be explored for therapeutic applications in leukemia. PMID:24244478

Pujari, Radha; Eligar, Sachin M.; Kumar, Natesh; Barkeer, Srikanth; Reddy, Vishwanath; Swamy, Bale M.; Inamdar, Shashikala R.; Shastry, Padma



Cytotoxic T cells directed to tumor antigens not expressed on normal melanocytes dominate HLA-A2.1-restricted immune repertoire to melanoma.  


To determine whether HLA-A21 restricted melanoma Ags exist that are not expressed on normal melanocytes, a panel of 478 T cell clones from six HLA-A21+ patients was selected for HLA-A2 restricted lysis of autologous tumor and then tested for differential recognition of HLA-A2.1+ melanomas and normal melanocytes. Four subsets of clones were identified in the panel of 107 HLA-A2-restricted CTL clones. CTL clones from three of the four subsets did not lyse melanocytes, but recognized fresh HLA-A2.1+ melanomas and defined three classes of epitopes, including unique Ags, common melanoma Ags, and Ags shared with neoplastic cells of different histologic origin. These CTL clones did not recognize any of the 10 peptides selected for specific association to HLA-A2.1 and derived from Melan-A/Mart-1, tyrosinase, gp100, or MAGE-3 proteins. By contrast, the fourth subset of HLA-A2.1-restricted CTl clones recognized both melanoma and melanocytes. These CTL clones were directed to a peptide from either Melan-A/Mart-1, tyronise, or gp100. By a limiting dilution assay, designed to evaluate the frequency of HLA-A2-restricted CTL precursors (CTLp) directed to melanoma but not to melanocytes, such precursors were found in the peripheral blood or tumor site of five of six HLA-A2.1+ melanoma patients, and their frequency was much higher than the frequency of CTLp recognizing both tumor cells and the melanocytes. These results suggest that in melanoma patients most of the HLA-A2.1-restricted immune repertoire to melanoma is directly to epitopes expressed in the neoplastic but not in the normal cells of the melanocyte lineage. PMID:8598464

Anichini, A; Mortarini, R; Maccalli, C; Squarcina, P; Fleischhauer, K; Mascheroni, L; Parmiani, G



Development of ?? T cell subset responses in gnotobiotic pigs infected with human rotaviruses and colonized with probiotic lactobacilli.  


?? T cell responses are induced by various viral and bacterial infections. Different ?? T cells contribute to activation and regulation of the inflammatory response and to epithelial repair. How ?? T cells respond to rotavirus infection and how the colonization of probiotics influences the ?? T cell response were unknown. In this study, we evaluated by multicolor flow cytometry the frequencies and distribution of total ?? T cells and three major subsets (CD2-CD8-, CD2+CD8- and CD2+CD8+) in ileum, spleen and blood of gnotobiotic (Gn) pigs at early (3-5 days) and late phases (28 days) after rotavirus infection. The Gn pigs were inoculated with the virulent human rotavirus Wa strain and colonized with a mixture of two strains of probiotics Lactobacillus acidophilus and Lactobacillus reuteri. In naïve pigs, the highest frequency of total ?? T cells was found in blood, followed by spleen and ileum at the early age (8-10 days old) whereas in older pigs (32 days of age) the highest frequency of total ?? T cells was found in ileum and spleen followed by blood. Rotavirus infection significantly increased frequencies of intestinal total ?? T cells and the putatively regulatory CD2+CD8+ ?? T cell subset and decreased frequencies of the putatively proinflammatory CD8- subsets in ileum, spleen and blood at post-infection days (PID) 3 or 5. The three ?? T cell subsets distributed and responded differently after rotavirus infection and/or lactobacilli colonization. The CD2+CD8+ subset contributed the most to the expansion of total ?? T cells after rotavirus infection in ileum because more than 77% of the total ?? T cells there were CD2+CD8+ cells. There was an additive effect between lactobacilli and rotavirus in inducing total ?? T cell expansion in ileum at PID 5. The overall effect of lactobacilli colonization versus rotavirus infection on frequencies of the CD2+CD8+ ?? T cell subset in ileum was similar; however, rotavirus-infected pigs maintained significantly higher frequencies of CD8- subsets in ileum than lactobacilli-colonized pigs. The dynamic ?? T cell responses suggest that ?? T cell subsets may play important roles in different stages of immune responses after rotavirus infection and probiotic colonization. The knowledge on the kinetics and distribution patterns of ?? T cell subsets in naïve pigs and after rotavirus infection or lactobacilli colonization provides the foundation for further mechanistic studies of their functions. PMID:21489639

Wen, Ke; Li, Guohua; Zhang, Wei; Azevedo, Marli S P; Saif, Linda J; Liu, Fangning; Bui, Tammy; Yousef, Ahmed; Yuan, Lijuan



Development of ?? T cell subset responses in gnotobiotic pigs infected with human rotaviruses and colonized with probiotic lactobacilli  

PubMed Central

?? T cell responses are induced by various viral and bacterial infections. Different ?? T cells contribute to activation and regulation of the inflammatory response and to epithelial repair. How ?? T cells respond to rotavirus infection and how the colonization of probiotics influences the ?? T cell response were unknown. In this study, we evaluated by multicolor flow cytometry the frequencies and distribution of total ?? T cells and three major subsets (CD2?CD8?, CD2+CD8? and CD2+CD8+) in ileum, spleen and blood of gnotobiotic (Gn) pigs at early (3–5 days) and late phases (28 days) after rotavirus infection. The Gn pigs were inoculated with the virulent human rotavirus Wa strain and colonized with a mixture of two strains of probiotics Lactobacillus acidophilus and Lactobacillus reuteri. In naive pigs, the highest frequency of total ?? T cells was found in blood, followed by spleen and ileum at the early age (8–10 days old) whereas in older pigs (32 days of age) the highest frequency of total ?? T cells was found in ileum and spleen followed by blood. Rotavirus infection significantly increased frequencies of intestinal total ?? T cells and the putatively regulatory CD2+CD8+ ?? T cell subset and decreased frequencies of the putatively proinflammatory CD8? subsets in ileum, spleen and blood at post-infection days (PID) 3 or 5. The three ?? T cell subsets distributed and responded differently after rotavirus infection and/or lactobacilli colonization. The CD2+CD8+ subset contributed the most to the expansion of total ?? T cells after rotavirus infection in ileum because more than 77% of the total ?? T cells there were CD2+CD8+ cells. There was an additive effect between lactobacilli and rotavirus in inducing total ?? T cell expansion in ileum at PID 5. The overall effect of lactobacilli colonization versus rotavirus infection on frequencies of the CD2+CD8+ ?? T cell subset in ileum was similar; however, rotavirus-infected pigs maintained significantly higher frequencies of CD8? subsets in ileum than lactobacilli-colonized pigs. The dynamic ?? T cell responses suggest that ?? T cell subsets may play important roles in different stages of immune responses after rotavirus infection and probiotic colonization. The knowledge on the kinetics and distribution patterns of ?? T cell subsets in naïve pigs and after rotavirus infection or lactobacilli colonization provides the foundation for further mechanistic studies of their functions. PMID:21489639

Wen, Ke; Li, Guohua; Zhang, Wei; Azevedo, Marli SP; Saif, Linda J; Liu, Fangning; Bui, Tammy; Yousef, Ahmed; Yuan, Lijuan



A targeted mutation at the T-cell receptor alpha/delta locus impairs T-cell development and reveals the presence of the nearby antiapoptosis gene Dad1.  

PubMed Central

Locus control regions are cis gene regulatory elements comprised of DNase I-hypersensitive sites. These regions usually do not stimulate transcription outside of a chromosomal context, and therefore their ability to regulate the expression of genes is thought to occur through the modification of chromatin accessibility. A locus control region is located downstream of the T-cell receptor (TCR) alpha/delta locus on mouse chromosome 14. This locus control region is known to drive T-cell-specific TCR alpha transcription in transgenic mice. In this report, we describe a targeted deletion of this locus control region and show that this mutation acts at a critical checkpoint in alphabeta T-cell development, between the TCR-intermediate and TCR-high stages. Our analysis further reveals that the antiapoptosis gene Dad1 is at the 3' end of the TCR alpha/delta locus and that Dad1 is required for embryogenesis. We show that mouse Dad1 has a broader expression pattern than the TCR genes, in terms of both tissue and temporal specificity. Finally, we report that the chromatin between TCR alpha and Dad1 is DNase I hypersensitive in a variety of cell types, thus correlating with Dad1 expression and raising the possibility that Dad1 regulatory sequences reside in this region. PMID:9121464

Hong, N A; Cado, D; Mitchell, J; Ortiz, B D; Hsieh, S N; Winoto, A



Intrathymic proliferation wave essential for V?14+ natural killer T cell development depends on c-Myc  

PubMed Central

The molecular requirements for invariant V?14-bearing natural killer T cells (iNKT) in the thymus are poorly understood. A minute population of ?500 newly selected CD69+CD24+ stage 0 (ST0) iNKT cells gives rise to ?100 times more CD44neg/loCD24? stage 1 (ST1) cells, which then generate similar frequencies of CD44hiCD24? stage 2 (ST2) and mature iNKT cells. Although the increased number of ST1 compared with ST0 cells indicates the initiation of a proliferation wave in the very early stages of iNKT cell development, details about the controlling mechanism are currently lacking. Here, we show that the transcription factor c-Myc is required for iNKT cell development. Conditional ablation of c-Myc in double-positive thymocytes specifically impacted iNKT but not conventional T cell development. Within the iNKT population, a progressive reduction of iNKT cells was observed starting at ST1 (?50-fold) and ST2 (?350-fold), with a complete lack of mature cells in thymus, spleen, and liver. ST0/ST1 c-Myc-deficient iNKT cells showed reduced proliferation. In contrast, annexin V staining did not reveal increased apoptosis, and transgenic overexpression of BCL-2 did not rescue iNKT cell development in c-Myc-deficient mice. Moreover, expression of known iNKT differentiation factors such as Plzf and Gata3 was not dramatically altered. These, findings provide compelling evidence that c-Myc mediates an intrathymic proliferation wave immediately after agonist selection of iNKT cells and illustrate the importance of this expansion for the generation of mature iNKT cells in vivo. PMID:19423665

Dose, Marei; Sleckman, Barry P.; Han, Jin; Bredemeyer, Andrea L.; Bendelac, Albert; Gounari, Fotini



Tumor-infiltrating regulatory T cells inhibit endogenous cytotoxic T cell responses to lung adenocarcinoma  

PubMed Central

Immune cells comprise a substantial proportion of the tumor mass in human non-small cell lung cancers (NSCLC), but the precise composition and significance of this infiltration is unclear. Herein we examined immune complexity of human NSCLC as well as NSCLC developing in CC10-TAg transgenic mice, and revealed that CD4+ T lymphocytes represent the dominant population of CD45+ immune cells, and relative to normal lung tissue, CD4+FoxP3+ regulatory T cells (Tregs) were significantly increased as a proportion of total CD4+ cells. To assess the functional significance of increased Treg cells, we evaluated CD8+ T cell-deficient/CC10-TAg mice and revealed that CD8+ T cells significantly controlled tumor growth with anti-tumor activity that was partially repressed by Treg cells. However, while treatment with anti-CD25 depleting mAb as monotherapy preferentially depleted Tregs and improved CD8+ T cell-mediated control of tumor progression during early tumor development, similar monotherapy was ineffective at later stages. Since mice bearing early NSCLC treated with anti-CD25 mAb exhibited increased tumor cell death associated with infiltration by CD8+ T cells expressing elevated levels of granzyme A, granzyme B, perforin and interferon-?, we therefore evaluated carboplatin combination therapy resulting in a significantly extended survival beyond that observed with chemotherapy alone, indicating that Treg depletion in combination with cytotoxic therapy may be beneficial as a treatment strategy for advanced NSCLC. PMID:23851682

Ganesan, Anusha-Preethi; Johansson, Magnus; Ruffell, Brian; Beltran, Adam; Lau, Jonathan; Jablons, David M.; Coussens, Lisa M.



Oxidative Stress, T Cell DNA Methylation, and Lupus  

PubMed Central

Objective Lupus develops when genetically predisposed people encounter environmental agents, such as ultraviolet light, silica, infections, and cigarette smoke, that cause oxidative stress, but how oxidative damage modifies the immune system to cause lupus flares is unknown. We previously showed that inhibiting DNA methylation in CD4+ T cells by blocking ERK pathway signaling is sufficient to alter gene expression, and that the modified cells cause lupus-like autoimmunity in mice. We also reported that T cells from patients with active lupus have decreased ERK pathway signaling, have decreased DNA methylation, and overexpress genes normally suppressed by DNA methylation. This study was undertaken to test whether oxidizing agents decrease ERK pathway signaling in T cells, decrease DNA methyltransferase levels, and cause demethylation and overexpression of T cell genes similar to that found in T cells from patients with active lupus. Methods CD4+ T cells were treated with the oxidizers H2O2 or ONOO?. Effects on ERK pathway signaling were measured by immunoblotting, DNA methyltransferase 1 (DNMT-1) levels were measured by reverse transcriptase–polymerase chain reaction (RT-PCR), and the methylation and expression of T cell genes were measured using flow cytometry, RT-PCR, and bisulfite sequencing. Results H2O2 and ONOO? inhibited ERK pathway signaling in T cells by inhibiting the upstream regulator protein kinase C?, decreased DNMT-1 levels, and caused demethylation and overexpression of genes previously shown to be suppressed by DNA methylation in T cells from patients with active lupus. Conclusion Our findings indicate that oxidative stress may contribute to human lupus flares by inhibiting ERK pathway signaling in T cells to decrease DNMT-1 and cause DNA demethylation. PMID:24577881

Li, YePeng; Gorelik, Gabriela; Strickland, Faith M; Richardson, Bruce C



Differential requirement for the SAP-Fyn interaction during natural killer T cell development and function13  

PubMed Central

The adaptor molecule SAP plays a critical role during natural killer T (NKT) cell development in humans and mice. In CD4+ T cells, SAP interacts with the tyrosine kinase Fyn to deliver signals required for TCR-induced TH2-type cytokine production. To determine whether the SAP-dependent signals controlling NKT cell ontogeny rely on its binding to Fyn, we used the OP9-DL1 system to initiate structure function studies of SAP in murine NKT cell development. In cultures containing wild type (WT) hematopoietic progenitors, we noted the transient emergence of cells that reacted with the NKT cell-specific agonist ?-galactosyl ceramide (?-GC) and its analogue PBS57. Sap?/? cells failed to give rise to NKT cells in vitro; however, their development could be rescued by re-expression of WT SAP. Emergence of NKT cells was also restored by a mutant version of SAP (SAP R78A) that cannot bind to Fyn, but with less efficiency than WT SAP. This finding was accentuated in vivo in SapR78A knock-in mice as well as SapR78A competitive bone marrow chimeras, which retained NKT cells but at significantly reduced numbers compared to controls. Unlike SapR78A CD4+ T cells, which produce reduced levels of IL-4 following TCR ligation, ?-GC-stimulated NKT cells from the livers and spleens of SapR78A mice produced TH2 cytokines and activated NK cells in a manner mimicking WT cells. Thus, SAP appears to use differential signaling mechanisms in NKT cells, with optimal ontogeny requiring Fyn binding, while functional responses occur independent of this interaction. PMID:18684920

Nunez-Cruz, Selene; Yeo, W.C. Janice; Rothman, Jennifer; Ojha, Priti; Bassiri, Hamid; Juntilla, Marisa; Davidson, Dominique; Veillette, André; Koretzky, Gary A.; Nichols, Kim E.



Large granular lymphocytes provide an accessory function in the in vitro development of influenza A virus-specific cytotoxic T cells.  


We report that large granular lymphocytes (LGL) have an accessory function in the development of cytotoxic T cells (Tc) through the production of soluble factor(s). LGL and T cells were separated on Percoll gradients and the ability of the separated and of the recombined LGL and T cells to generate influenza A virus-specific Tc activity was measured. When stimulated by virus-infected, irradiated, adherent cells, neither LGL nor T cells cultured separately produced Tc activity. When they were co-cultured, however, even if separated by a 0.22-micron pore size membrane, Tc responses were readily generated from the small T cell precursors and natural killer activity was maintained in the LGL. Thus, LGL were required as accessory cells for Tc responses to occur and the effect was mediated by a soluble factor(s). alpha-Interferon (IFN) was produced in cultures containing LGL and/or stimulating adherent cells, whereas gamma-IFN was only produced in cultures containing both LGL and T cells. Therefore, neither alpha- nor gamma-IFN appeared to be the LGL produced soluble factor that mediated the accessory effect of LGL on Tc responses. PMID:6202775

Burlington, D B; Djeu, J Y; Wells, M A; Kiley, S C; Quinnan, G V



Chung-Yeul-Gue-Soup-Sa-Gan-Tang, traditional Korean medicine, enhances CD4(+) T cell activities and modulates Th1/Th2 lineage development.  


Chung-Yeul-Gue-Soup-Sa-Gan-Tang (CYT), a traditional Korea herbal medicine, has been widely used in Korea for the treatment of various immunological disorders, including allergic asthma. In this study, CYT was examined in vitro and tested for possible immunological effects. The results demonstrated that CYT had no mitogenic effects on unstimulated CD4(+) T cells, but rather increased CD4(+) T cell proliferation upon activation with anti-CD3/CD28 antibody. Under the Th0 condition, CYT also enhanced expression of interleukin (IL)-2 in purified murine CD4(+) T cells assayed by real-time PCR, suggesting that CYT moderately increases the activity of helper T cells upon T cell receptor ligation under the neutral condition. However, the Th1 cells were overpopulated following CYT treatment under the Th1 condition, while Th2 cells were under-populated in the Th2 driven condition. In addition, under Th1/Th2-skewed conditions, the levels of IL-4 were considerably decreased, while the expression of T-bet and interferon-gamma were increased with CYT treatment. Thus, CYT enhances Th1 lineage development from naive CD4(+) T cells both by increasing Th1 specific cytokine secretion and repressing Th2 specific cytokine production. These results suggest that CYT is a desirable agent for the correction of Th2 dominant pathological disorders. PMID:15107575

Ko, Eunjung; Park, Jae-Woo; Rho, Samwoong; Cho, Chongwoon; Park, Seongkyu; Ko, Seonggyu; Lee, Yongwon; Hong, Moo-Chang; Shin, Min-Kyu; Ryu, Ki-Won; Bae, Hyunsu



Vitamin D3 metabolite calcidiol primes human dendritic cells to promote the development of immunomodulatory IL-10-producing T cells.  


Vitamin D is recognized as a potent immunosuppressive drug. The suppressive effects of vitamin D are attributed to its physiologically active metabolite 1,25 dihydroxy vitamin D3 (calcitriol), which was shown, to prime dendritic cells (DCs) to promote the development of regulatory T (Treg) cells. Despite the potential benefit in treating autoimmune diseases, clinical application of calcitriol is hindered by deleterious side effects manifested by hypercalcemia and hypercalciuria. Conversely, the physiological precursors of calcitriol, vitamin D3 (cholecalciferol) and its first metabolite 25-hydroxy vitamin D3 (calcidiol) are widely applied in the clinic due to their low calcimic burden. However, the mechanisms by which cholecalciferol and calcidiol may modulate adaptive immunity remain elusive. This prompted us to unravel the immunosuppressive capacity of these precursors by assessing their influence on DC functions and the subsequent polarization of naïve CD4(+) T cells. In this study we show that, whereas cholecalciferol has insignificant effects on DC maturation and cytokine production, it only weakly primed DCs to induce suppressive T cells. However, like calcitriol, calcidiol not only exerted an inhibitory effect on DC maturation and cytokine production, and primed DCs to promote the development of suppressive IL-10-producing Treg cells. Strikingly, in contrast to the population of IL-10-producing Treg cells induced by calcitriol-primed DCs, the IL-10-producing Treg cells induced by calcidiol-primed DCs exhibited sustained IFN-? production in face of their suppressive capacity. Experiments with the steroid synthesis inhibitor ketoconazole indicated that the immunomodulatory features of the precursors are dependent on their conversion into calcitriol. Collectively, calcidiol is a potent immune modulator, which may be more adequate than calcitriol for the treatment of chronic inflammatory diseases, since it is less hypercalcimic. This may be of particular interest for the treatment of allergic disease, where concurrent suppression and sustained IFN-? production by Treg cells effectively counterbalance the Th2-dominated immune responses. PMID:25236584

Bakdash, Ghaith; van Capel, Toni M M; Mason, Lauren M K; Kapsenberg, Martien L; de Jong, Esther C



The bone marrow of myeloma patients is steadily inhabited by a normal-sized pool of functional regulatory T cells irrespectiveof the disease status  

PubMed Central

Conflicting data have been reported about the frequency and function of regulatory T cells in multiple myeloma. Most studies have investigated peripheral blood rather than bone marrow Tregs and side-by-side comparisons with bone marrow from healthy donors have still not been made. In this study, we show that regulatory T-cells total count, subset distribution, and expression of chemokine receptors are similar in the bone marrow of myeloma patients and healthy donors. Regulatory T cells are not recruited by myeloma cells in the bone marrow and their counts are unaffected by the tumor burden and the disease status. The diversity of T-cell receptor repertoire is highly preserved ensuring broad reactivity and effective suppressor function. Our results indicate that regulatory T cells may not be the main players of immunological tolerance to myeloma cells under base-line conditions, but their fully preserved immune competence may promote their inadvertent activation and blunt T-cell driven anti-myeloma immune interventions even after myeloma cells have successfully been cleared by chemotherapy. PMID:24972771

Foglietta, Myriam; Castella, Barbara; Mariani, Sara; Coscia, Marta; Godio, Laura; Ferracini, Riccardo; Ruggeri, Marina; Muccio, Vittorio; Omedé, Paola; Palumbo, Antonio; Boccadoro, Mario; Massaia, Massimo



Follicular helper T-cells: expanding roles in T-cell lymphoma and targets for treatment.  


Follicular helper T-cells (Tfh cells) are a subset of CD4(+) T-cells that are essential for normal production of high affinity antibodies. Tfh cells characteristically produce IL21 and IL4 and show high expression of surface markers CXCR5, ICOS, PDCD1 (PD-1) and the chemokine CXCL13. In this review we will focus on the emerging links between Tfh cells and subtypes of T-cell non-Hodgkin lymphoma: angioimmunoblastic T-cell lymphoma (AITL) and ~20% of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) have surface marker features of Tfh cells and share a spectrum of genetic abnormalities. The recurrent genetic abnormalities associated with AITL include mutations in epigenetic modifiers such as TET2 and DNMT3A and the motility and adhesion gene, RHOA, is mutated in up to 70% of cases. ~20% of PTCL-NOS demonstrate RHOA mutations and have other characteristics suggesting an origin in Tfh cells. The recognition that specific genetic and surface markers are associated with malignant Tfh cells suggests that the next few years will bring major changes in diagnostic and treatment possibilities. For example, antibodies against IL21, PDCD1 and ICOS are already in clinical trials for autoimmune disease or other malignancies and antibodies against CXCL13 are in pre-clinical development. PMID:24815671

Ahearne, Matthew J; Allchin, Rebecca L; Fox, Christopher P; Wagner, Simon D



Lack of reactive oxygen species breaks T cell tolerance to collagen type II and allows development of arthritis in mice.  


The view on reactive oxygen species (ROS) in inflammation is currently shifting from being considered damaging toward having a more complex role in regulating inflammatory reactions. We recently demonstrated a role of ROS in regulation of animal models for the autoimmune disease rheumatoid arthritis. Low levels of ROS production, due to a mutation in the Ncf1 gene coding for the Ncf1 (alias p47(phox)) subunit of the NADPH oxidase complex, was shown to be associated with increased autoimmunity and arthritis severity in both rats and mice. To further investigate the role of ROS in autoimmunity, we studied transgenic mice expressing collagen type II (CII) with a mutation (D266E) in the immunodominant epitope that mimics the rat and human CII (i.e., mutated mouse collagen or MMC). This mutation results in a stronger binding of the epitope to the MHC class II molecule and leads to more pronounced tolerance and resistance to arthritis induced with rat CII. When the Ncf1 mutation was bred into these mice, tolerance was broken, resulting in enhanced T cell autoreactivity, high titers of anti-CII Abs, and development of severe arthritis. These findings highlight the importance of a sufficient ROS production in maintenance of tolerance to self-Ags, a central mechanism in autoimmune diseases such as rheumatoid arthritis. This is important as we, for the first time, can follow the effect of ROS on molecular mechanisms where T cells are responsible for either protection or promotion of arthritis depending on the level of oxygen species produced. PMID:17641008

Hultqvist, Malin; Bäcklund, Johan; Bauer, Kristin; Gelderman, Kyra A; Holmdahl, Rikard



A Novel Molecular Complex Expressed on Immature B Cells: A Possible Role in T Cell-Independent B Cell Development  

PubMed Central

To identify surface molecules that may play a role in regulating ileal Peyer's patch (PP) B cell growth, we generated monoclonal antibodies (mAbs) and then selected them for a unique reactivity with ileal PP B cells. Flow cytometric analysis identified a mAb (SIC4.8R) that labeled 97% of ileal and 50–60% of jejunal PP sIgM+B cells. SIC4.8R also labeled a subpopulation of cortical thymocytes but few B or T cells in other lymphoid tissues, including bone marrow. Immunohistochemistry revealed intense SIC4.8R staining of B cells in the cortex of ileal PP follicles. SIC4.8R also labeled bovine PP B cells, a murine pro-B cell line, and pre-B cells in human bone marrow. Protein chemistry revealed that a structurally similar molecular complex was expressed on sheep ileal PP B cells and thymocytes and murine pro-B cells. Addition of soluble SIC4.8R to cultured ileal PP B cells reduced apoptotic cell death, elevated proliferative responses, partially inhibited anti-Ig-induced cell death, and induced IL-4 responsiveness. In contrast, soluble SIC4.8R had an antiproliferative effect on a mouse pro-B cell line. Finally, SIC4.8R labeling declined following the stimulation of ileal PP B cells with CD40 ligand. In conclusion, the present investigation determined that SIC4.8R identified a novel molecular complex that is expressed at several stages of T cell-independent B cell development in a variety of mammalian species. This observation confirmed that PP B cells are developmentally distinct from other B cell populations in sheep and suggested that the bone marrow may not be a site of B lymphopoiesis in young lambs. PMID:8828012

Ghia, Paolo; Grawunder, Ulf; Ferrari, Giorgio



Thymic Epithelial Requirement for ?? T Cell Development Revealed in the Cell Ablation Transgenic System with TSCOT Promoter  

PubMed Central

In order to investigate the role of thymic epithelial cell (TEC) subsets during T-cell development, we established a new transgenic system, enabling inducible cell-specific ablation as well as marking the TEC subsets using bicistronic bacterial nitroreductase and EGFP genes. Two different lengths of the TSCOT promoter in transgenic mice, named 3.1T-NE and 9.1T-NE, drive EGFP expression into TECs. In adult life, EGFP expression was located in the medulla with a smaller 3.1 kb TSCOT promoter, while it was maintained in the cortex with a 9.1 kb promoter, suggesting putative TEC specific as well as compartment specific cis elements within two promoters. Nitroreductase induced cell death was specific without bystander killing upon the treatment of prodrugs such as nitrofurantoin and metronidazol. The degree of cell death was dependent on the dose of the prodrug in the cell and the fetal thymic organ cultures (FTOCs). Fetal thymic stromal populations were analyzed based on the expression levels of EpCAM, MHCII, CDR1 and/or UEA-1. EGFP expression patterns varied among subsets indicating the differential TSCOT promoter activity in each TEC subset. Prodrug treatment in FTOCs reduced the numbers of total and subsets of thymocytes. A CD4+CD8+ double positive cell population was highly susceptible in both transgenic lines. Surprisingly, there was a distinct reduction in ?? T cell population only in the 9.1T-NE thymus, indicating that they require a NTREGFP expressing TEC population. Therefore, these results support a division of labor within TEC subsets for the ?? and ?? lineage specification. PMID:23178972

Lee, Gwanghee; Kim, Ki Yeon; Chang, Cheong-Hee; Kim, Moon Gyo



Essential functions for ID proteins at multiple checkpoints in natural killer T cell development  

PubMed Central

Invariant natural killer T (iNKT) cells display characteristics of both adaptive and innate lymphoid cells (ILCs). Like other ILCs, iNKT cells constitutively express ID proteins, which antagonize the E protein transcription factors that are essential for adaptive lymphocyte development. However, unlike ILCs, ID2 is not essential for thymic iNKT cell development. Here we demonstrated that ID2 and ID3 redundantly promoted iNKT cell lineage specification involving the induction of the signature transcription factor PLZF and that ID3 was critical for development of TBET-dependent NKT1 cells. In contrast, both ID2 and ID3 limited iNKT cell numbers by enforcing the post-selection checkpoint in conventional thymocytes. Therefore, iNKT cells show both adaptive and innate-like requirements for ID proteins at distinct checkpoints during iNKT cell development. PMID:24244015

Verykokakis, Mihalis; Krishnamoorthy, Veena; Iavarone, Antonio; Lasorella, Anna; Sigvardsson, Mikael; Kee, Barbara L.



9-cis-retinoic acid inhibits activation-driven T-cell apoptosis: implications for retinoid X receptor involvement in thymocyte development.  


Retinoic acid is a morphogenetic signaling molecule derived from vitamin A and involved in vertebrate development. Two groups of receptors, retinoic acid receptors and retinoid X receptors (RXRs), have been identified. All-trans-retinoic acid is the high-affinity ligand for retinoic acid receptors, and 9-cis-retinoic acid additionally binds RXRs with high affinity. Here we report that although retinoic acid has little inhibitory effect on activation-induced T-cell proliferation, it specifically prevents activation-induced apoptosis of T-cell hybridomas and antigen-specific deletion of immature CD4+CD8+ thymocytes from alpha beta T-cell receptor transgenic mice. 9-cis-Retinoic acid was approximately 10-fold more potent than all-trans-retinoic acid, suggesting that RXRs participate in this process. Thus, although 9-cis-retinoic acid has little immuno-suppressive activity, it is a potent negative regulator of activation-induced T-cell apoptosis, raising the possibility that RXRs may take part in regulating T-cell development. PMID:8392190

Yang, Y; Vacchio, M S; Ashwell, J D



Enforced expression of GATA3 during T cell development inhibits maturation of CD8 single-positive cells and induces thymic lymphoma in transgenic mice  

Microsoft Academic Search

The zinc finger transcription factor GATA-3 is of critical importance for\\u000a early T cell development and commitment of Th2 cells. To study the role of\\u000a GATA-3 in early T cell development, we analyzed and modified GATA-3\\u000a expression in vivo. In mice carrying a targeted insertion of a lacZ\\u000a reporter on one allele, we found that GATA-3 transcription in CD4(+)CD8(+)\\u000a double-positive

M. C. Nawijn; R. Ferreira; G. M. Dingjan; O. Kahre; D. D. Drabek; A. Karis; R. W. Hendriks; F. G. Grosveld



T-cell count  


Thymus derived lymphocyte count; T-lymphocyte count ... T cells are a type of lymphocyte. Lymphocytes are white blood cells. They make up part of the immune system. T cells help the body fight diseases or harmful ...


Retinoic acids exert direct effects on T cells to suppress Th1 development and enhance Th2 development via retinoic acid receptors.  


The vitamin A metabolite, retinoic acid (RA), affects Th1 and Th2 development. The effect is partly exerted through the modulation of antigen-presenting cell functions, but it remains unclear whether RA directly exerts its effect on T cells to influence Th1/Th2 development. To clarify this problem, we used two experimental systems with isolated T cells in vitro. In one system, isolated CD4+CD8+ thymocytes differentiated into Th1 and Th2 by two transient stimulations with defined combinations of ionomycin and phorbol myristate acetate followed by treatment with IL-2 and IL-4 and/or IL-12. In the second system, functional differentiation was induced in purified naive CD4 T cells from DO-11.10 TCR-transgenic and RAG-2-deficient mice with cytokines and antibodies to CD3 and CD28. In both systems, all-trans-RA at > or = 1 nM concentrations suppressed Th1 development, but enhanced Th2 development. 9-cis-RA elicited similar effects. The optimal enhancement of Th2 development in the second system, however, was achieved with a delayed addition of RA. The presence of RA during the initial stimulation period often suppressed Th2 development. The RA receptor (RAR) antagonists, LE540 and LE135, but not the retinoic X receptor (RXR) antagonist, PA452, inhibited the effect of RA on Th1/Th2 development. Accordingly, the RAR agonists, Am80 and Tp80, but not the RXR agonists, HX600 and TZ335, mimicked the effect of RA. The RXR agonists enhanced the effect of the RAR agonists only slightly, if at all. These results indicate that, via RAR, RA directly suppresses Th1 development and directly enhances Th2 development with its timely addition. PMID:12882839

Iwata, Makoto; Eshima, Yuko; Kagechika, Hiroyuki



The role of Ras guanine nucleotide releasing protein 4 in Fc epsilonRI-mediated signaling, mast cell function, and T cell development.  


The RasGRP (Ras guanine nucleotide-releasing protein) family proteins are guanine nucleotide exchange factors that activate Ras GTPases, ultimately leading to MAPK activation and many cellular processes. The RasGRP family has four members. Published studies demonstrate that RasGRP1, RasGRP2, and RasGRP3 play critical roles in T cells, platelets, and B cells, respectively. RasGRP4 is highly expressed in mast cells. Although previous data suggest that it is important in mast cell development and function, the role of RasGRP4 in mast cells and allergic responses has not been clearly demonstrated. In this study, we generated RasGRP4(-/-) mice to examine the function of RasGRP4. Analyses of these mice showed that mast cells were able to develop normally in vivo and in vitro. Despite high levels of RasGRP4 expression in mast cells, RasGRP4 deficiency led to only a modest reduction in Fc?RI-mediated degranulation and cytokine production. Interestingly, mast cells deficient in both RasGRP1 and RasGRP4 had a much more severe block in Fc?RI-mediated signaling and mast cell function. We also made the unexpected finding that RasGRP4 functions during thymocyte development. Our data suggest that after the engagement of immunoreceptors, immune cells likely employ multiple members of the RasGRP family to transduce critical signals. PMID:22262848

Zhu, Minghua; Fuller, Deirdre M; Zhang, Weiguo



The Role of Ras Guanine Nucleotide Releasing Protein 4 in Fc?RI-mediated Signaling, Mast Cell Function, and T Cell Development*  

PubMed Central

The RasGRP (Ras guanine nucleotide-releasing protein) family proteins are guanine nucleotide exchange factors that activate Ras GTPases, ultimately leading to MAPK activation and many cellular processes. The RasGRP family has four members. Published studies demonstrate that RasGRP1, RasGRP2, and RasGRP3 play critical roles in T cells, platelets, and B cells, respectively. RasGRP4 is highly expressed in mast cells. Although previous data suggest that it is important in mast cell development and function, the role of RasGRP4 in mast cells and allergic responses has not been clearly demonstrated. In this study, we generated RasGRP4?/? mice to examine the function of RasGRP4. Analyses of these mice showed that mast cells were able to develop normally in vivo and in vitro. Despite high levels of RasGRP4 expression in mast cells, RasGRP4 deficiency led to only a modest reduction in Fc?RI-mediated degranulation and cytokine production. Interestingly, mast cells deficient in both RasGRP1 and RasGRP4 had a much more severe block in Fc?RI-mediated signaling and mast cell function. We also made the unexpected finding that RasGRP4 functions during thymocyte development. Our data suggest that after the engagement of immunoreceptors, immune cells likely employ multiple members of the RasGRP family to transduce critical signals. PMID:22262848

Zhu, Minghua; Fuller, Deirdre M.; Zhang, Weiguo



Peptide-MHC multimer-based monitoring of CD8 T-cells in HIV-1 infection and AIDS vaccine development.  


The use of MHC multimers allows precise and direct detecting and analyzing of antigen-specific T-cell populations and provides new opportunities to characterize T-cell responses in humans and animals. MHC-multimers enable us to enumerate specific T-cells targeting to viral, tumor and vaccine antigens with exceptional sensitivity and specificity. In the field of HIV/SIV immunology, this technique provides valuable information about the frequencies of HIV- and SIV-specific CD8(+) cytotoxic T lymphocytes (CTLs) in different tissues and sites of infection, AIDS progression, and pathogenesis. Peptide-MHC multimer technology remains a very sensitive tool in detecting virus-specific T -cells for evaluation of the immunogenicity of vaccines against HIV-1 in preclinical trials. Moreover, it helps to understand how immune responses are formed following vaccination in the dynamics from priming point until T-cell memory is matured. Here we review a diversity of peptide-MHC class I multimer applications for fundamental immunological studies in different aspects of HIV/SIV infection and vaccine development. PMID:25373312

Reguzova, Alena Y; Karpenko, Larisa I; Mechetina, Ludmila V; Belyakov, Igor M



Induced and Natural Regulatory T Cells in the Development of Inflammatory Bowel Disease  

PubMed Central

The mucosal immune system mediates contact between the host, and the trillions of microbes that symbiotically colonize the gastrointestinal tract. Failure to tolerate the antigens within this “extended self” can result in inflammatory bowel disease (IBD). Within the adaptive immune system, the most significant cells modulating this interaction are Foxp3+ regulatory T (Treg) cells. Treg cells can be divided into two primary subsets: “natural” Treg (nTreg) cells, and “adaptive” or “induced” Treg (iTreg). Recent research suggests that these subsets serve to play both independent and synergistic roles in mucosal tolerance. Studies from both mouse models and human patients suggest defects in Treg cells can play distinct causative roles in IBD. Numerous genetic, microbial, nutritional, and environmental factors that associate with IBD may also affect Treg cells. In this review we summarize the development and function of Treg cells, and how their regulatory mechanisms may fail, leading to a loss of mucosal tolerance. We discuss both animal models and studies of IBD patients suggesting Treg cell involvement in IBD, and consider how Treg cells may be used in future therapies. PMID:23656897

Mayne, Christopher G.; Williams, Calvin B.



Milk: an exosomal microRNA transmitter promoting thymic regulatory T cell maturation preventing the development of atopy?  


Epidemiological evidence confirmed that raw cow's milk consumption in the first year of life protects against the development of atopic diseases and increases the number of regulatory T-cells (Tregs). However, milk's atopy-protective mode of action remains elusive.This review supported by translational research proposes that milk-derived microRNAs (miRs) may represent the missing candidates that promote long-term lineage commitment of Tregs downregulating IL-4/Th2-mediated atopic sensitization and effector immune responses. Milk transfers exosomal miRs including the ancient miR-155, which is important for the development of the immune system and controls pivotal target genes involved in the regulation of FoxP3 expression, IL-4 signaling, immunoglobulin class switching to IgE and Fc?RI expression. Boiling of milk abolishes milk's exosomal miR-mediated bioactivity. Infant formula in comparison to human breast- or cow's milk is deficient in bioactive exosomal miRs that may impair FoxP3 expression. The boost of milk-mediated miR may induce pivotal immunoregulatory and epigenetic modifications required for long-term thymic Treg lineage commitment explaining the atopy-protective effect of raw cow's milk consumption.The presented concept offers a new option for the prevention of atopic diseases by the addition of physiological amounts of miR-155-enriched exosomes to infant formula for mothers incapable of breastfeeding. PMID:24521175

Melnik, Bodo C; John, Swen Malte; Schmitz, Gerd



Bach2 maintains T cells in a naive state by suppressing effector memory-related genes.  


The transcriptional repressor BTB and CNC homology 2 (Bach2) is thought to be mainly expressed in B cells with specific functions such as class switch recombination and somatic hypermutation, but its function in T cells is not known. We found equal Bach2 expression in T cells and analyzed its function using Bach2-deficient (-/-) mice. Although T-cell development was normal, numbers of peripheral naive T cells were decreased, which rapidly produced Th2 cytokines after TCR stimulation. Bach2(-/-) naive T cells highly expressed genes related to effector-memory T cells such as CCR4, ST-2 and Blimp-1. Enhanced expression of these genes induced Bach2(-/-) naive T cells to migrate toward CCR4-ligand and respond to IL33. Forced expression of Bach2 restored the expression of these genes. Using Chromatin Immunoprecipitation (ChIP)-seq analysis, we identified S100 calcium binding protein a, Heme oxigenase 1, and prolyl hydroxylase 3 as Bach2 direct target genes, which are highly expressed in effector-memory T cells. These findings indicate that Bach2 suppresses effector memory-related genes to maintain the naive T-cell state and regulates generation of effector-memory T cells. PMID:23754397

Tsukumo, Shin-ichi; Unno, Midori; Muto, Akihiko; Takeuchi, Arata; Kometani, Kohei; Kurosaki, Tomohiro; Igarashi, Kazuhiko; Saito, Takashi



Thymic regulatory T cells.  


Several types of T regulatory (Treg) cells have been described in both mice and humans, including natural or professional (CD4+CD25+ T cells) and adaptive (Th3 and Tr1 cells) Treg cells. The former develops in the thymus and results in an endogeneous long-lived population of self-antigen-specific T cells in the periphery poised to prevent potentially autoimmune reactions. The second subset develops as a consequence of activation of mature T cells under particular conditions of sub-optimal antigen exposure and/or costimulation. Natural Treg cells are positively selected in the cortex through their TCR interactions with self-peptides presented by thymic stromal cells. It is likely that this high-affinity recognition results in signals rendering them anergic and able to produce anti-apoptoptic molecules which protect them from negative selection. Recently, small subsets of CD4+CD25+ and of CD8+CD25+ cells sharing similar characteristics have been detected in human fetal and post-natal thymuses. Both CD4+CD25+ and CD8+CD25+ human thymocytes express Foxp3 and GITR mRNA, as well as surface CCR8 and TNFR2 and cytoplasmic CTLA-4 proteins, which are common features of mature Treg cells. Following activation they do not proliferate or produce cytokines, but express surface CTLA-4 and TGF-beta1. They suppress the proliferation of autologous CD4+CD25- thymocytes to allogeneic stimulation by a contact-dependent mechanism related to the combined action of surface CTLA-4 and TGF-beta leading to the inhibition of the IL-2R alpha chain on target T cells. Lastly, both CD4+CD25+ and CD8+CD25+ Treg thymocytes exert strong suppressive activity on Th1, but much lower on Th2 cells, since these latter may escape from suppression via their ability to respond to growth factors other than IL-2. Treg cells that develop in, and emerge from, the thymus are certainly responsible for the maintenance of self-tolerance and prevention of autoimmune disorders. The result that Th1 cells are highly susceptible to the suppressive activity of Treg thymocytes is consistent with the important role of these cells in protecting against the Th1-mediated immune response to autoantigens. PMID:16214099

Maggi, Enrico; Cosmi, Lorenzo; Liotta, Francesco; Romagnani, Paola; Romagnani, Sergio; Annunziato, Francesco



Multilayered specification of the T-cell lineage fate  

PubMed Central

Summary T-cell development from stem cells has provided a highly accessible and detailed view of the regulatory processes that can go into the choice of a cell fate in a postembryonic, stem cell-based system. But, it has been a view from the outside. The problems in understanding the regulatory basis for this lineage choice begin with the fact that too many transcription factors are needed to provide crucial input: without any one of them, T-cell development fails. Furthermore, almost all the factors known to provide crucial functions during the climax of T-lineage commitment itself are also vital for earlier functions that establish the pool of multilineage precursors that would normally feed into the T-cell specification process. When the regulatory genes that encode them are mutated, the confounding effects on earlier stages make it difficult to dissect T-cell specification genetically. Yet both the positive and the negative regulatory events involved in the choice of a T-cell fate are actually a mosaic of distinct functions. New evidence has emerged recently that finally provides a way to separate the major components that fit together to drive this process. Here, we review insights into T-cell specification and commitment that emerge from a combination of molecular, cellular, and systems biology approaches. The results reveal the regulatory structure underlying this lineage decision. PMID:20969591

Rothenberg, Ellen V.; Zhang, Jingli; Li, Long



The challenges and opportunities for the development of a T-cell epitope-based herpes simplex vaccine.  


Herpes simplex virus type 1 and type 2 (HSV-1 & HSV-2) infections have been prevalent since the ancient Greek times. To this day, they still affect a staggering number of over a billion individuals worldwide. HSV-1 infections are predominant than HSV-2 infections and cause potentially blinding ocular herpes, oro-facial herpes and encephalitis. HSV-2 infections cause painful genital herpes, encephalitis, and death in newborns. While prophylactic and therapeutic HSV vaccines remain urgently needed for centuries, their development has been difficult. During the most recent National Institute of Health (NIH) workshop titled "Next Generation Herpes Simplex Virus Vaccines: The Challenges and Opportunities", basic researchers, funding agencies, and pharmaceutical representatives gathered: (i) to assess the status of herpes vaccine research; and (ii) to identify the gaps and propose alternative approaches in developing a safe and efficient herpes vaccine. One "common denominator" among previously failed clinical herpes vaccine trials is that they either used a whole virus or a whole viral protein, which contain both "pathogenic symptomatic" and "protective asymptomatic" antigens and epitopes. In this report, we continue to advocate developing "asymptomatic" epitope-based sub-unit vaccine strategies that selectively incorporate "protective asymptomatic" epitopes which: (i) are exclusively recognized by effector memory CD4(+) and CD8(+) T cells (TEM cells) from "naturally" protected seropositive asymptomatic individuals; and (ii) protect human leukocyte antigen (HLA) transgenic animal models of ocular and genital herpes. We review the role of animal models in herpes vaccine development and discuss their current status, challenges, and prospects. PMID:25446827

Kuo, Tiffany; Wang, Christine; Badakhshan, Tina; Chilukuri, Sravya; BenMohamed, Lbachir



T Cell-Dendritic Cell Interaction in Vivo: Random Encounters Favor Development of Long-Lasting Ties  

NSDL National Science Digital Library

Understanding the complexity of the functional communication between cells composing the immune system is central to improving our capacity to manipulate it and conceive better strategies to combat microbial pathogens. So far, these studies have been based on immunohistochemistry of fixed tissues and in vitro attempts to reproduce functional connections between cells. The application of two-photon laser microscopy to the observation of viable immune cells in their natural environment where foreign antigens are carried to trigger an immune response opens a new era for these studies. They reveal exceptional properties of the locomotion of T cells that facilitate encounters with dendritic cells and the receipt of information that promotes T cell survival, death, or initiation of immune responses. These studies also complement in vitro observations addressing the importance of time of stimulation in determining T cell fates.

Oreste Acuto (Institut Pasteur;Molecular Immunology Unit, Department of Immunology REV)



Upregulation of Nuclear Factor of Activated T-Cells by Nerve Injury Contributes to Development of Neuropathic Pain  

PubMed Central

Nerve injury induces long-term changes in gene expression in the nociceptive circuitry and can lead to chronic neuropathic pain. However, the transcriptional mechanism involved in neuropathic pain is poorly understood. Nuclear factor of activated T-cells (NFATc) is a transcriptional factor regulated by the Ca2+-dependent protein phosphatase calcineurin. In this study, we determined nerve injury–induced changes in the expression of NFATc1–c4 in the dorsal root ganglia (DRG) and spinal cords and their role in the development of neuropathic pain. The mRNA of NFATc1–c4 was detected in the rat DRG and dorsal spinal cord. Nerve injury transiently elevated NFATc1–c3 mRNA levels and persistently increased NFATc4 and C-C chemokine receptor type 2 (CCR2) mRNA levels in the DRG. However, NFATc1–c4 mRNA levels in the spinal cord were not altered significantly by nerve injury. Nerve injury also significantly increased the protein level of dephosphorylated NFATc4 in the DRG. Intrathecal injection of the specific NFATc inhibitor 11R-VIVIT or the calcineurin inhibitor FK-506 (tacrolimus) early after nerve injury significantly attenuated the development of tactile allodynia. In addition, treatment with FK-506 or 11R-VIVIT significantly reduced the mRNA levels of NFATc4 and CCR2 but not large-conductance Ca2+-activated K+ channels, in the DRG after nerve injury. Our findings suggest that peripheral nerve injury causes a time-dependent change in NFATc1–c4 expression in the DRG. Calcineurin-NFATc–mediated expression of pronociceptive cytokines contributes to the transition from acute to chronic pain after nerve injury. PMID:23386250

Cai, You-Qing; Chen, Shao-Rui



Intradermal application of vitamin D3 increases migration of CD14+ dermal dendritic cells and promotes the development of Foxp3+ regulatory T cells  

PubMed Central

The active form of vitamin D3 (VitD) is a potent immunosuppressive drug. Its effects are mediated in part through dendritic cells (DCs) that promote the development of regulatory T cells (Tregs). However, it remains elusive how VitD would influence the different human skin DC subsets, e.g., CD1a+/langerin+ Langerhans cells, CD14+ DDCs and CD1a+ DDCs upon administration through the skin route in their natural environment. We addressed this issue by intradermal (ID) administration of VitD in a human skin explant system that closely resembles physiological conditions. ID injection of VitD selectively enhanced the migration of CD14+ DDCs, a subset known for the induction of tolerance. Moreover, ID injection of VitD repressed the LPS-induced T cell stimulatory capacity of migrating DCs. These migrating DCs collectively induced T cells with suppressive activity and abolished IFN-? productivity. Those induced T cells were characterized by the expression of Foxp3. Thus, we report the novel finding that ID injection of VitD not only modifies skin DC migration, but also programs these DCs in their natural milieu to promote the development of Foxp3+ Tregs. PMID:23291929

Bakdash, Ghaith; Schneider, Laura P.; van Capel, Toni M. M.; Kapsenberg, Martien L.; Teunissen, Marcel B. M.; de Jong, Esther C.



Interleukin (IL) 15/IL-T production by the adult T-cell leukemia cell line HuT-102 is associated with a human T-cell lymphotrophic virus type I region /IL-15 fusion message that lacks many upstream AUGs that normally attenuates IL-15 mRNA translation.  

PubMed Central

We reported previously that the human T-cell lymphotrophic virus type I (HTLV-I)-associated adult T-cell leukemia line HuT-102 produces a cytokine designated interleukin (IL) T that requires interleukin (IL) 2 receptor beta-subunit expression for its action. Using anti-cytokine antibodies, we demonstrated that IL-T is identical to the simultaneously described IL-15. When compared to activated monocytes, IL-15 mRNA expression was 6- to 10-fold greater in HuT-102 cells. The predominant IL-15 message from HuT-102 is a chimeric mRNA joining a segment of the R region of the long terminal repeat of HTLV-I and the 5'-untranslated region (UTR) of IL-15. Normally, by alternative splicing, this 118-nucleotide R element represents the most 5' region of several HTLV-I transcripts including tax, rex, and env. The introduction of the R element eliminated over 200 nucleotides of the IL-15 5'-UTR, including 8 of 10 upstream AUGs that are present in normal IL-15 messages. On analysis of the 5'-UTR of normal IL-15, we demonstrated that the presence of these 10 upstream AUGs interferes with IL-15 mRNA translation. Thus, IL-15 synthesis by the adult T-cell leukemia line HuT- 102 involves an increase in IL-15 mRNA transcription and translation secondary to the production of an HTLV-I R element fusion message that lacks many upstream AUGs. Images Fig. 1 Fig. 4 PMID:8610139

Bamford, R N; Battiata, A P; Burton, J D; Sharma, H; Waldmann, T A



Striking lack of T cell immunodominance in both a multiclade and monoclade HIV-1 epidemic: implications for vaccine development.  


Understanding the impact of HIV diversity on immunological responses to candidate immunogens is critical for HIV vaccine development. We investigated the reactivity and immunodominance patterns of HIV-1 consensus group M Gag and Nef in (i) Cameroon, where individuals infected with the predominant CRF02_AG clade were compared with those infected with diverse non-CRF02_AG clades; and (ii) in a multiclade epidemic, namely Cameroon, compared with a monoclade C epidemic, South Africa. We analyzed 57 HIV-infected individuals from Cameroon and 44 HIV-infected individuals from South Africa for differences in detecting HIV-1 consensus M Gag and Nef T cell responses using the IFN-? ELISpot assay. We found no difference in the predicted epitope coverage between CRF02_AG and non-CRF02_AG viruses for either Gag or Nef. There were no differences in the magnitude and breadth of responses for CRF02_AG and non-CRF02_AG-infected individuals. In contrast, the specificity of epitope targeting was markedly different between the two groups, with fewer than one third (11/38) of peptides commonly recognized in Gag. Furthermore, only one peptide was commonly recognized by at least three individuals from both AG and non-AG groups, indicating poor immunodominance. For Nef, more than half of all targeted peptides (14/27) were recognized by both groups, and four peptides were commonly targeted by at least three individuals. Three times more peptides were exclusively targeted in the diverse non-CRF02_AG group compared to the CRF02_AG group (10 vs. 3). Of note, similar results were obtained when South Africa, a monoclade C epidemic, and Cameroon, a multiclade epidemic, were compared. The central nature of HIV-1 consensus M sequences resulted in their broad recognition, but failed to identify highly immunodominant peptides between homogeneous and diverse HIV epidemics. PMID:24598726

Tongo, Marcel; Zembe, Lycias; Ebong, Eugenie; Roux, Surita; Bekker, Linda-Gail; Williamson, Carolyn; Mpoudi-Ngole, Eitel; Burgers, Wendy A



CD4+ T cells recognize diverse epitopes within GAD65: implications for repertoire development and diabetes monitoring  

PubMed Central

Summary Type 1 diabetes is associated with T?cell responses to ??cell antigens such as GAD65. Single T?cell epitopes have been investigated for immune monitoring with some success, but multiple epitopes may be required to fully characterize responses in all subjects. We used a systematic approach to examine the diversity of the GAD65?specific T?cell repertoire in subjects with DRB1*04:01 haplotypes. Using class II tetramers, we observed responses to 15 GAD65 epitopes, including five novel epitopes. The majority were confirmed to be processed and presented. Upon stimulation with peptides, GAD?specific responses were equally broad in subjects with diabetes and healthy controls in the presence or absence of CD25+ T cells, suggesting that a susceptible HLA is sufficient to generate a potentially autoreactive repertoire. Without depleting CD25+ cells, GAD113–132 and GAD265–284 responses were significantly stronger in subjects with diabetes. Although nearly every individual responded to at least one GAD65 epitope, most were seen in less than half of the subjects tested, suggesting that multiple epitopes are recommended for immune monitoring. PMID:23228173

Yang, Junbao; James, Eddie A.; Sanda, Srinath; Greenbaum, Carla; Kwok, William W.



Major histocompatibility complex class I related molecules control the development of CD4+8- and CD4-8- subsets of natural killer 1.1+ T cell receptor-alpha/beta+ cells in the liver of mice  

PubMed Central

Normal mouse liver contains prominent subsets of CD4+8- and CD4-8- T cell receptor (TCR)-alpha/beta+ cells with intermediate TCR levels. We show here that these cells express the natural killer (NK)1.1 surface antigen and have a restricted TCRV beta repertoire that is highly skewed to V beta 7 and V beta 8. Surprisingly, both CD4+8- and CD4-8- subsets of NK1.1+TCR-alpha/beta+ cells are absent in the liver of beta 2-microglobulin deficient mice, which do not express major histocompatibility complex (MHC) class I or "class I-like" molecules. Analysis of reciprocal radiation bone marrow chimeras established with beta 2-microglobulin deficient and wild-type mice demonstrates that MHC class I expression on radiosensitive (presumably hematopoietic) cells is required for the development of NK1.1+TCR-alpha/beta+ cells in the liver. In the liver of MHC class II deficient mice, the CD4+8- and CD4- 8- subsets of NK1.1+TCR-alpha/beta+ cells develop normally. Collectively our data suggest that NK1.1+TCR-alpha/beta+ cells in liver require interaction with a MHC class I-related ligand on hematopoietic cells for their development. This unusual property of liver T cells is shared by a subset of CD4-8-NK1.1+TCR-alpha/beta+ thymocytes, suggesting a common lineage independent of the mainstream of T cell development. PMID:8046344



Interleukin 17–producing CD4+ effector T cells develop via a lineage distinct from the T helper type 1 and 2 lineages  

Microsoft Academic Search

CD4+ T cells producing interleukin 17 (IL-17) are associated with autoimmunity, although the precise mechanisms that control their development are undefined. Here we present data that challenge the idea of a shared developmental pathway with T helper type 1 (TH1) or TH2 lineages and instead favor the idea of a distinct effector lineage we call 'TH-17'. The development of TH-17

Laurie E Harrington; Robin D Hatton; Paul R Mangan; Henrietta Turner; Theresa L Murphy; Kenneth M Murphy; Casey T Weaver



Follicular T-cell lymphoma: a member of an emerging family of follicular helper T-cell derived T-cell lymphomas.  


Unlike B-cell lymphomas, where knowledge of normal B-cell origin and differentiation has greatly contributed to their classification, the current classification of peripheral T-cell lymphomas is limited by a lack of understanding of their cellular origin. In the current World Health Organization classification of lymphomas, follicular T-cell lymphoma was formally recognized as a morphologic variant of peripheral T-cell lymphoma, not otherwise specified. There is growing evidence, however, that follicular T-cell lymphoma may be a unique clinicopathologic entity based on its morphologic features and derivation from follicular helper T-cells. In addition, there are abundant recent data supporting the concept that follicular helper T-cells can give rise to other types of T-cell lymphoma, including angioimmunoblastic T-cell lymphoma, primary cutaneous CD4+ small/medium T-cell lymphoma, and a subset of neoplasms, in addition to follicular T-cell lymphoma, currently classified as peripheral T-cell lymphoma, not otherwise specified. In this review, we focus primarily on the clinicopathologic, immunophenotypic, and molecular features of follicular T-cell lymphoma and discuss its potential relationship with other types of T-cell lymphoma thought to be derived from follicular helper T-cells. PMID:22959759

Hu, Shimin; Young, Ken H; Konoplev, Sergej N; Medeiros, L Jeffrey



Developments in allergen-specific immunotherapy: from allergen extracts to allergy vaccines bypassing allergen-specific immunoglobulin E and T cell reactivity.  


Allergen-specific immunotherapy (SIT) is the only specific and disease-modifying approach for the treatment of allergy but several disadvantages have limited its broad applicability. We argue that the majority of the possible disadvantages of SIT such as unwanted effects, poor efficacy and specificity as well as inconvenient application are related to the poor quality of natural allergen extracts, which are the active ingredients of all currently available allergy vaccines. Because of the progress made in the field of molecular allergen characterization, new allergy vaccines based on recombinant allergens, recombinant hypoallergenic allergen derivatives and allergen-derived T cell peptides have entered clinical testing and hold promise to reduce the side-effects and to increase the specificity as well as the efficacy of SIT. Here, we present a refined immunotherapy concept, which is based on the use of peptides derived from allergen surfaces that exhibit reduced, allergen-specific IgE as well as T cell reactivity. These peptides when fused to non-allergenic carriers give rise to allergen-specific protective IgG responses with T cell help from a non-allergenic carrier molecule. We summarize the experimental data demonstrating that such peptide vaccines can bypass allergen-specific IgE as well as T cell activation and may be administered at high doses without IgE- and T cell-mediated side-effects. Should these peptide vaccines prove efficacious and safe in clinical trials, it may become possible to develop convenient, safe and broadly applicable forms of SIT as true alternatives to symptomatic, drug-based allergy treatment. PMID:20210812

Focke, M; Swoboda, I; Marth, K; Valenta, R



Epigenetics in T-cell acute lymphoblastic leukemia.  


Normal T-cell development is a strictly regulated process in which hematopoietic progenitor cells migrate from the bone marrow to the thymus and differentiate from early T-cell progenitors toward mature and functional T cells. During this maturation process, cooperation between a variety of oncogenes and tumor suppressors can drive immature thymocytes into uncontrolled clonal expansion and cause T-cell acute lymphoblastic leukemia (T-ALL). Despite improved insights in T-ALL disease biology and comprehensive characterization of its genetic landscape, clinical care remained largely similar over the past decades and still consists of high-dose multi-agent chemotherapy potentially followed by hematopoietic stem cell transplantation. Even with such aggressive treatment regimens, which are often associated with considerable side effects, clinical outcome is still extremely poor in a significant subset of T-ALL patients as a result of therapy resistance or hematological relapses. Recent genetic studies have identified recurrent somatic alterations in genes involved in DNA methylation and post-translational histone modifications in T-ALL, suggesting that epigenetic homeostasis is critically required in restraining tumor development in the T-cell lineage. In this review, we provide an overview of the epigenetic regulators that could be implicated in T-ALL disease biology and speculate how the epigenetic landscape of T-ALL could trigger the development of epigenetic-based therapies to further improve the treatment of human T-ALL. PMID:25510271

Peirs, Sofie; Van der Meulen, Joni; Van de Walle, Inge; Taghon, Tom; Speleman, Frank; Poppe, Bruce; Van Vlierberghe, Pieter



CXC chemokine receptor 4 expressed in T cells plays an important role in the development of collagen-induced arthritis  

Microsoft Academic Search

INTRODUCTION: Chemokines and their receptors are potential therapeutic targets in rheumatoid arthritis (RA). Among these, several studies suggested the involvement of CXC chemokine 4 (CXCR4) and its ligand CXC ligand 12 (SDF-1) in RA pathogenesis. However, the role of these molecules in T-cell function is not known completely because of embryonic lethality of Cxcr4- and Cxcl12-deficient mice. In this report,

Soo-Hyun Chung; Keisuke Seki; Byung-Il Choi; Keiko B Kimura; Akihiko Ito; Noriyuki Fujikado; Shinobu Saijo; Yoichiro Iwakura



Regulation of RasGRP1 Function in T Cell Development and Activation by Its Unique Tail Domain  

PubMed Central

The Ras-guanyl nucleotide exchange factor RasGRP1 plays a critical role in T cell receptor-mediated Erk activation. Previous studies have emphasized the importance of RasGRP1 in the positive selection of thymocytes, activation of T cells, and control of autoimmunity. RasGRP1 consists of a number of well-characterized domains, which it shares with its other family members; however, RasGRP1 also contains an ?200 residue-long tail domain, the function of which is unknown. To elucidate the physiological role of this domain, we generated knock-in mice expressing RasGRP1 without the tail domain. Further analysis of these knock-in mice showed that thymocytes lacking the tail domain of RasGRP1 underwent aberrant thymic selection and, following TCR stimulation, were unable to activate Erk. Furthermore, the deletion of the tail domain led to enhanced CD4+ T cell expansion in aged mice, as well as the production of autoantibodies. Mechanistically, the tail-deleted form of RasGRP1 was not able to traffic to the cell membrane following stimulation, indicating a potential reason for its inability to activate Erk. While the DAG-binding C1 domain of RasGRP1 has long been recognized as an important factor mediating Erk activation, we have revealed the physiological relevance of the tail domain in RasGRP1 function and control of Erk signaling. PMID:22719950

Fuller, Deirdre M.; Zhu, Minghua; Song, Xiaohua; Ou-Yang, Chih-wen; Sullivan, Sarah A.; Stone, James C.; Zhang, Weiguo



Pushing the frontiers of T-cell vaccines: accurate measurement of human T-cell responses  

PubMed Central

There is a need for novel approaches to tackle major vaccine challenges such as malaria, tuberculosis and HIV, among others. Success will require vaccines able to induce a cytotoxic T-cell response – a deficiency of most current vaccine approaches. The successful development of T-cell vaccines faces many hurdles, not least being the lack of consensus on a standardized T-cell assay format able to be used as a correlate of vaccine efficacy. Hence, there remains a need for reproducible measures of T-cell immunity proven in human clinical trials to correlate with vaccine protection. The T-cell equivalent of a neutralizing antibody assay would greatly accelerate the development and commercialization of T-cell vaccines. Recent advances have seen a plethora of new T-cell assays become available, including some like cytometry by time-of-flight with extreme multiparameter T-cell phenotyping capability. However, whether it is historic thymidine-based proliferation assays or sophisticated new cytometry assays, each assay has its relative advantages and disadvantages, and relatively few of these assays have yet to be validated in large-scale human vaccine trials. This review examines the current range of T-cell assays and assesses their suitability for use in human vaccine trials. Should one or more of these assays be accepted as an agreed surrogate of T-cell protection by a regulatory agency, this would significantly accelerate the development of T-cell vaccines. PMID:23252389

Saade, Fadi; Gorski, Stacey Ann; Petrovsky, Nikolai



Regulatory T Cells in B Cell Follicles  

PubMed Central

Understanding germinal center reactions is crucial not only for the design of effective vaccines against infectious agents and malignant cells but also for the development of therapeutic intervention for the treatment of antibody-mediated immune disorders. Recent advances in this field have revealed specialized subsets of T cells necessary for the control of B cell responses in the follicle. These cells include follicular regulatory T cells and Qa-1-restricted cluster of differentiation (CD)8+ regulatory T cells. In this review, we discuss the current knowledge related to the role of regulatory T cells in the B cell follicle. PMID:25360073

Chang, Jae-Hoon



Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis.  


Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch(ICN-TG)). Following exposure of adult Notch(ICN-TG) mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3?g/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch(ICN-TG) offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch(ICN-TG) offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. PMID:25585350

Ahrenhoerster, Lori S; Leuthner, Tess C; Tate, Everett R; Lakatos, Peter A; Laiosa, Michael D



APRIL-Deficient Mice Have Normal Immune System Development  

PubMed Central

APRIL (a proliferation-inducing ligand) is a member of the tumor necrosis factor (TNF) superfamily. APRIL mRNA shows high levels of expression in tumors of different origin and a low level of expression in normal cells. APRIL shares two TNF receptor family members, TACI and BCMA, with another TNF homolog, BLyS/BAFF. BLyS is involved in regulation of B-cell activation and survival and also binds to a third receptor, BR3/BAFF-R, which is not shared with APRIL. Recombinant APRIL and BLyS induce accumulation of B cells in mice, while BLyS deficiency results in severe B-cell dysfunction. To investigate the physiological role of APRIL, we generated mice that are deficient in its encoding gene. APRIL?/? mice were viable and fertile and lacked any gross abnormality. Detailed histological analysis did not reveal any defects in major tissues and organs, including the primary and secondary immune organs. T- and B-cell development and in vitro function were normal as well, as were T-cell-dependent and -independent in vivo humoral responses to antigenic challenge. These data indicate that APRIL is dispensable in the mouse for proper development. Thus, BLyS may be capable of fulfilling APRIL's main functions. PMID:14729948

Varfolomeev, Eugene; Kischkel, Frank; Martin, Flavius; Seshasayee, Dhaya; Wang, Hua; Lawrence, David; Olsson, Christine; Tom, Lucrece; Erickson, Sharon; French, Dorothy; Schow, Peter; Grewal, Iqbal S.; Ashkenazi, Avi



T cells in myositis  

PubMed Central

T cells of both the CD4 and CD8 lineage are commonly found in affected tissues of patients with idiopathic inflammatory myopathies, but understanding the contribution of these cells to immunopathogenesis remains challenging. Given recent advances in identifying more myositis-associated autoantibodies and their putative targets, we suggest that studies on autoreactive T cells targeting those autoantigens are one way forward. Another (so far, more frequently used) approach comes from studies on effector T cells in the context of myositis. This review summarizes recent advances and current hypotheses in both of these contexts. PMID:23270751



CD8+ T cells are effector cells of contact dermatitis to common skin allergens in mice.  


Allergic contact dermatitis (ACD) to strong experimental haptens is mediated by specific CD8+ T cells. Here, we show that similar mechanisms occur for weak haptens, which comprise the vast majority of chemicals responsible for human ACD. We used a model of ACD, that is, the contact hypersensitivity reaction, to test for the allergenicity of three weak haptens involved in fragrance allergy. ACD to weak haptens could not be induced in normal mice. In contrast, mice acutely depleted in CD4+ T cells developed a typical ACD reaction to the three weak fragrance allergens that peaked 24 hours after challenge. Priming of CD8+ T cells was observed in draining lymph nodes 5 days after sensitization and development of ACD was associated with the infiltration of activated CD8+ T cells in the challenged skin. CD8+ T cells were effectors of the ACD reaction as in vivo treatment with depleting anti-CD8 mAbs abrogated the ACD responses and as purified CD8+ T cells could adoptively transfer ACD to naive recipients. In conclusion, our data demonstrate a dominant role of CD8+ T cells as initiators of ACD to weak haptens, and suggest that CD8+ T cells may represent potential targets for preventing or treating ACD. PMID:16456532

Vocanson, Marc; Hennino, Anca; Cluzel-Tailhardat, Magalie; Saint-Mezard, Pierre; Benetiere, Josette; Chavagnac, Cyril; Berard, Frederic; Kaiserlian, Dominique; Nicolas, Jean-François



Expansion of CD4+CD25+ helper T cells without regulatory function in smoking and COPD  

PubMed Central

Background Regulatory T cells have been implicated in the pathogenesis of COPD by the increased expression of CD25 on helper T cells along with enhanced intracellular expression of FoxP3 and low/absent CD127 expression on the cell surface. Method Regulatory T cells were investigated in BALF from nine COPD subjects and compared to fourteen smokers with normal lung function and nine never-smokers. Results In smokers with normal lung function, the expression of CD25+CD4+ was increased, whereas the proportions of FoxP3+ and CD127+ were unchanged compared to never-smokers. Among CD4+ cells expressing high levels of CD25, the proportion of FoxP3+ cells was decreased and the percentage of CD127+ was increased in smokers with normal lung function. CD4+CD25+ cells with low/absent CD127 expression were increased in smokers with normal lung function, but not in COPD, when compared to never smokers. Conclusion The reduction of FoxP3 expression in BALF from smokers with normal lung function indicates that the increase in CD25 expression is not associated with the expansion of regulatory T cells. Instead, the high CD127 and low FoxP3 expressions implicate a predominantly non-regulatory CD25+ helper T-cell population in smokers and stable COPD. Therefore, we suggest a smoking-induced expansion of predominantly activated airway helper T cells that seem to persist after COPD development. PMID:21651772



Reassessing target antigens for adoptive T cell therapy  

PubMed Central

Adoptive T cell therapy can target and kill widespread malignant cells thereby inducing durable clinical responses in melanoma and selected other malignances. However, many commonly targeted tumor antigens are also expressed by healthy tissues, and T cells do not distinguish between benign and malignant tissues if both express the target antigen. As such, autoimmune toxicity from T-cell-mediated destruction of normal tissue has limited the development and adoption of this otherwise promising type of cancer therapy. A review of the unique biology of T-cell therapy and of recent clinical experience compels a reassessment of target antigens that traditionally have been viewed from the perspective of weaker immunotherapeutic modalities. In selecting target antigens for adoptive T-cell therapy, expression by tumors and not by essential healthy tissues is of paramount importance. The risk of autoimmune adverse events can be further mitigated by generating antigen receptors using strategies that reduce the chance of cross-reactivity against epitopes in unintended targets. In general, a circumspect approach to target selection and thoughtful preclinical and clinical studies are pivotal to the ongoing advancement of these promising treatments. PMID:24142051

Hinrichs, Christian S.; Restifo, Nicholas P.



WASH Knockout T Cells Demonstrate Defective Receptor Trafficking, Proliferation, and Effector Function  

PubMed Central

WASH is an Arp2/3 activator of the Wiskott-Aldrich syndrome protein superfamily that functions during endosomal trafficking processes in collaboration with the retromer and sorting nexins, but its in vivo function has not been examined. To elucidate the physiological role of WASH in T cells, we generated a WASH conditional knockout (WASHout) mouse model. Using CD4Cre deletion, we found that thymocyte development and naive T cell activation are unaltered in the absence of WASH. Surprisingly, despite normal T cell receptor (TCR) signaling and interleukin-2 production, WASHout T cells demonstrate significantly reduced proliferative potential and fail to effectively induce experimental autoimmune encephalomyelitis. Interestingly, after activation, WASHout T cells fail to maintain surface levels of TCR, CD28, and LFA-1. Moreover, the levels of the glucose transporter, GLUT1, are also reduced compared to wild-type T cells. We further demonstrate that the loss of surface expression of these receptors in WASHout cells results from aberrant accumulation within the collapsed endosomal compartment, ultimately leading to degradation within the lysosome. Subsequently, activated WASHout T cells experience reduced glucose uptake and metabolic output. Thus, we found that WASH is a newly recognized regulator of TCR, CD28, LFA-1, and GLUT1 endosome-to-membrane recycling. Aberrant trafficking of these key T cell proteins may potentially lead to attenuated proliferation and effector function. PMID:23275443

Piotrowski, Joshua T.; Gomez, Timothy S.; Schoon, Renee A.; Mangalam, Ashutosh K.



In situ recognition of autoantigen as an essential gatekeeper in autoimmune CD8+ T cell inflammation.  


A current paradigm states that non-antigen-specific inflammatory cues attract noncognate, bystander T cell specificities to sites of infection and autoimmune inflammation. Here we show that cues emanating from a tissue undergoing spontaneous autoimmune inflammation cannot recruit naive or activated bystander T cell specificities in the absence of local expression of cognate antigen. We monitored the recruitment of CD8(+) T cells specific for the prevalent diabetogenic epitope islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)(206-214) in gene-targeted nonobese diabetic (NOD) mice expressing a T cell "invisible" IGRP(206-214) sequence. These mice developed islet inflammation and diabetes with normal incidence and kinetics, but their inflammatory lesions could recruit neither naive (endogenous or exogenous) nor ex vivo-activated IGRP(206-214)-reactive CD8(+) T cells. Conversely, IGRP(206-214)-reactive, but not nonautoreactive CD8(+) T cells rapidly homed to and accumulated in the inflamed islets of wild-type NOD mice. Our results indicate that CD8(+) T cell recruitment to a site of autoimmune inflammation results from an active process that is strictly dependent on local display of cognate pMHC and suggest that CD8(+) T cells contained in extralymphoid autoimmune lesions are largely autoreactive. PMID:20439719

Wang, Jinguo; Tsai, Sue; Shameli, Afshin; Yamanouchi, Jun; Alkemade, Gonnie; Santamaria, Pere



T cells promote the regeneration of neural precursor cells in the hippocampus of Alzheimer's disease mice  

PubMed Central

Alzheimer's disease is closely associated with disorders of neurogenesis in the brain, and growing evidence supports the involvement of immunological mechanisms in the development of the disease. However, at present, the role of T cells in neuronal regeneration in the brain is unknown. We injected amyloid-beta 1–42 peptide into the hippocampus of six BALB/c wild-type mice and six BALB/c-nude mice with T-cell immunodeficiency to establish an animal model of Alzheimer's disease. A further six mice of each genotype were injected with same volume of normal saline. Immunohistochemistry revealed that the number of regenerated neural progenitor cells in the hippocampus of BALB/c wild-type mice was significantly higher than that in BALB/c-nude mice. Quantitative fluorescence PCR assay showed that the expression levels of peripheral T cell-associated cytokines (interleukin-2, interferon-?) and hippocampal microglia-related cytokines (interleukin-1?, tumor necrosis factor-?) correlated with the number of regenerated neural progenitor cells in the hippocampus. These results indicate that T cells promote hippocampal neurogenesis in Alzheimer's disease and T-cell immunodeficiency restricts neuronal regeneration in the hippocampus. The mechanism underlying the promotion of neuronal regeneration by T cells is mediated by an increased expression of peripheral T cells and central microglial cytokines in Alzheimer's disease mice. Our findings provide an experimental basis for understanding the role of T cells in Alzheimer's disease. PMID:25317172

Liu, Jing; Ma, Yuxin; Tian, Sumin; Zhang, Li; Zhao, Mengmeng; Zhang, Yaqiong; Xu, Dachuan



Bovine ?? T Cells Are a Major Regulatory T Cell Subset  

PubMed Central

In humans and mice, ?? T cells represent <5% of the total circulating lymphocytes. In contrast, the ?? T cell compartment in ruminants accounts for 15–60% of the total circulating mononuclear lymphocytes. Despite the existence of CD4+CD25high Foxp3+ T cells in the bovine system, these are neither anergic nor suppressive. We present evidence showing that bovine ?? T cells are the major regulatory T cell subset in peripheral blood. These ?? T cells spontaneously secrete IL-10 and proliferate in response to IL-10, TGF-?, and contact with APCs. IL-10–expressing ?? T cells inhibit Ag-specific and nonspecific proliferation of CD4+ and CD8+ T cells in vitro. APC subsets expressing IL-10 and TFG-? regulate proliferation of ?? T cells producing IL-10. We propose that ?? T cells are a major regulatory T cell population in the bovine system. PMID:24890724

Hope, Jayne; Taylor, Geraldine; Smith, Adrian L.; Cubillos-Zapata, Carolina; Charleston, Bryan



Reduction of T Cell Receptor Diversity in NOD Mice Prevents Development of Type 1 Diabetes but Not Sjögren’s Syndrome  

PubMed Central

Non-obese diabetic (NOD) mice are well-established models of independently developing spontaneous autoimmune diseases, Sjögren’s syndrome (SS) and type 1 diabetes (T1D). The key determining factor for T1D is the strong association with particular MHCII molecule and recognition by diabetogenic T cell receptor (TCR) of an insulin peptide presented in the context of I-Ag7 molecule. For SS the association with MHCII polymorphism is weaker and TCR diversity involved in the onset of the autoimmune phase of SS remains poorly understood. To compare the impact of TCR diversity reduction on the development of both diseases we generated two lines of TCR transgenic NOD mice. One line expresses transgenic TCR? chain originated from a pathogenically irrelevant TCR, and the second line additionally expresses transgenic TCR?mini locus. Analysis of TCR sequences on NOD background reveals lower TCR diversity on Treg cells not only in the thymus, but also in the periphery. This reduction in diversity does not affect conventional CD4+ T cells, as compared to the TCRmini repertoire on B6 background. Interestingly, neither transgenic TCR? nor TCRmini mice develop diabetes, which we show is due to lack of insulin B:9–23 specific T cells in the periphery. Conversely SS develops in both lines, with full glandular infiltration, production of autoantibodies and hyposalivation. It shows that SS development is not as sensitive to limited availability of TCR specificities as T1D, which suggests wider range of possible TCR/peptide/MHC interactions driving autoimmunity in SS. PMID:25379761

Kern, Joanna; Drutel, Robert; Leanhart, Silvia; Bogacz, Marek; Pacholczyk, Rafal



Modulation of the innate immune response during Human T-cell Leukemia Virus infection: implication for development of an oncolytic vector.  

E-print Network

??Infection with human T cell Leukemia virus (HTLV-1) can cause Adult T-cell Leukemia (ATL) or the neurological disorder HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). Although the… (more)

Oliere, Stéphanie



Modulation of the innate immune response during human T-cell leukemia virus infection implications for development of an oncolytic virotherapy for ATL.  

E-print Network

??Infection with human T cell Leukemia virus (HTLV-1) can cause Adult T-cell Leukemia (ATL) or the neurological disorder HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). Although the… (more)

Oliere, Stéphanie



Using T-Cells for Transplantation and Autoimmune Therapy

Transplant complications and autoimmune diseases are primarily caused by T-cell immune responses against normal host tissue or transplanted tissues. Current treatment for these disorders is often not effective, and is typically associated with significant side effects, including global immune suppression. Researchers at NCI's Experimental Transplantation and Immunology Branch have developed a cellular therapy to treat graft-vs.-host disease (GVHD) that results from hematopoetic transplant and other autoimmune disorders.


Human T cell subsets.  


Several monoclonal antibodies (mAbs) demonstrate further heterogeneity of CD4 and CD8. Within CD4, two major subsets can be identified with helper/inducer and suppressor/inducer functions. It is argued that suppressor/inducers, identified by CD45R mAbs, are immature or virgin T cells and therefore respond poorly to recall antigens. Helper/inducers are CD45R negative but express the UCHL1 antigen, which appears to be part of CD45. These cells respond well to recall antigens and are therefore mature or memory T cells. Several antigens not related to CD45, such as 4B4, Leu8, TQ1 and 9.3, identify functionally distinct subsets rather than stages of T cell maturation. PMID:2953677

Beverley, P C



Visualizing T Cell Migration in situ  

PubMed Central

Mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid tissues. The structure of secondary lymphoid organs regulates immune responses by promoting optimal cell–cell and cell–extracellular matrix interactions. Naïve T cells are initially activated by antigen presenting cells in secondary lymphoid organs. Following priming, effector T cells migrate to the site of infection to exert their functions. Majority of the effector cells die while a small population of antigen-specific T cells persists as memory cells in distinct anatomical locations. The persistence and location of memory cells in lymphoid and non-lymphoid tissues is critical to protect the host from re-infection. The localization of memory T cells is carefully regulated by several factors including the highly organized secondary lymphoid structure, the cellular expression of chemokine receptors and compartmentalized secretion of their cognate ligands. This balance between the anatomy and the ordered expression of cell surface and soluble proteins regulates the subtle choreography of T cell migration. In recent years, our understanding of cellular dynamics of T cells has been advanced by the development of new imaging techniques allowing in situ visualization of T cell responses. Here, we review the past and more recent studies that have utilized sophisticated imaging technologies to investigate the migration dynamics of naïve, effector, and memory T cells. PMID:25120547

Benechet, Alexandre P.; Menon, Manisha; Khanna, Kamal M.



SOCS3 Deletion in T-Lymphocytes Suppresses Development of Chronic Ocular Inflammation Via Up-regulation of CTLA-4 and Expansion of Regulatory T cells  

PubMed Central

Suppressors of cytokine signaling (SOCS) proteins are negative-feedback regulators of JAK/STAT pathway and SOCS3 contributes to host immunity by regulating the intensity/duration of cytokine signals and inflammatory responses. Mice with Socs3 deletion in myeloid cells exhibit enhanced STAT3-signaling, expansion of Th1 and Th17 cells and developed severe experimental autoimmune encephalomyelitis (EAE). Interestingly, development of the unique IL-17/IFN-?-double producing (Th17/IFN-? and Tc17/IFN-?) subsets that exhibit strong cytotoxic activities and associated with pathogenesis of several autoimmune diseases, has recently been shown to depend on epigenetic suppression of SOCS3 expression, further suggesting involvement of SOCS3 in autoimmunity and tumor immunity. In this study, we generated mice with Socs3 deletion in CD4 T cell compartment (CD4-SOCS3KO) to determine in vivo effects of the loss of Socs3 in the T cell-mediated autoimmune disease, experimental autoimmune uveitis (EAU). In contrast to the exacerbation of EAE in myeloid-specific SOCS3-deleted mice, CD4-SOCS3KO mice were protected from acute and chronic uveitis. Protection from EAU correlated with enhanced expression of CTLA4 and expansion of IL-10 producing Tregs with augmented suppressive activities. We further show that SOCS3 interacts with CTLA4 and negatively regulates CTLA4 levels in T cells, providing mechanistic explanation for the expansion of Tregs in CD4-SOCS3 during EAU. Contrary to in vitro epigenetic studies, Th17/IFN-? and Tc17/IFN-? populations were markedly reduced in CD4-SOCS3KO, suggesting that SOCS3 promotes expansion of Th17/IFN-? subset associated with development of severe uveitis. Thus, SOCS3 is a potential therapeutic target in uveitis and other auto-inflammatory diseases. PMID:24101549

Yu, Cheng-Rong; Kim, Sung-Hye; Mahdi, Rashid M.; Egwuagu, Charles E.



Genetically Modified T Cells for the Treatment of Malignant Disease  

PubMed Central

Summary The broaden application of adoptive T-cell transfer has been constrained by the technical abilities to isolate and expand antigen-specific T cells potent to selectively kill tumor cells. With the recent progress in the design and manufacturing of cellular products, T cells used in the treatment of malignant diseases may be regarded as anticancer biopharmaceuticals. Genetical manipulation of T cells has given T cells desired specificity but also enable to tailor their activation and proliferation potential. Here, we summarize the recent developments in genetic engineering of T-cell-based biopharmaceuticals, covering criteria for their clinical application in regard to safety and efficacy. PMID:24474888

Wieczorek, Agnieszka; Uharek, Lutz



Natural killer T cells are essential for the development of contact hypersensitivity in BALB/c mice.  


Contact hypersensitivity (CHS) has been widely used to study cutaneous immune responses, as a prototype of delayed-type hypersensitivity. Although natural killer T (NKT) cells have been assumed to have an important role in CHS, their role is controversial. Here, we report the role of NKT cells in the sensitization phase of CHS, by promoting the survival and maturation of dendritic cells (DCs) in the draining lymph nodes (LNs). The CHS response was attenuated with Cd1d1(-/-) and Traj18(-/-) BALB/c mice in which NKT cells were absent. In the draining LNs, the number of effector T cells and cytokine production were significantly reduced with NKT cell-deficient mice. NKT cells activated and colocalized with DCs in the draining LNs after sensitization. The number of migrated and mature DCs was reduced in NKT cell-deficient mice 72?hours after FITC application. In in vitro experiments, activated NKT cells enhanced bone marrow-derived DC (BMDC) survivability via tumor necrosis factor (TNF) production from BMDCs. In addition, TNF production from BMDCs was partially suppressed by the neutralizing anti-CD54 or CD154 antibodies. Our data demonstrate that DC-NKT interaction has a pivotal role in the sensitization phase of CHS. PMID:24756110

Shimizuhira, Chihiro; Otsuka, Atsushi; Honda, Tetsuya; Kitoh, Akihiko; Egawa, Gyohei; Nakajima, Saeko; Nakashima, Chisa; Watarai, Hiroshi; Miyachi, Yoshiki; Kabashima, Kenji



Role of CD8(+) T-cell immunity in influenza infection: potential use in future vaccine development.  


Continued circulation of the highly pathogenic avian H5N1 influenza A virus has many people worried that an influenza pandemic is imminent. Compounding this is the realization that H5N1 vaccines based on current influenza vaccine technology (designed to generate protective antibody responses) may be suboptimal at providing protection. As a consequence, there is recent interest in vaccine strategies that elicit cellular immunity, particularly the cytotoxic T lymphocyte response, in an effort to provide protection against a potential pandemic. A major issue is the lack of information about the precise role that these 'hitmen' of the immune system have in protecting against both pandemic and seasonal influenza. We need to know more about how the induction and maintenance of cytotoxic T lymphocytes after influenza infection can impact protection from further infection. The challenge is then to use this information in the design of vaccines that will protect against pandemic influenza and will help optimize CD8(+) killer T-cell responses in other infections. PMID:20477341

La Gruta, Nicole; Kelso, Anne; Brown, Lorena E; Chen, Wiesan; Jackson, David C; Turner, Stephen J



T Cells Are Essential for Bacterial Clearance, and Gamma Interferon, Tumor Necrosis Factor Alpha, and B Cells Are Crucial for Disease Development in Coxiella burnetii Infection in Mice?  

PubMed Central

Coxiella burnetii, the etiological agent of Q fever, has two phase variants. Phase I has a complete lipopolysaccharide (LPS), is highly virulent, and causes Q fever in humans and pathology in experimental animals. Phase II lacks an LPS O side chain, is avirulent, and does not grow well in immunocompetent animals. To understand the pathogenicity of Q fever, we investigated the roles of immune components in animals infected with Nine Mile phase I (NM I) or Nine Mile phase II (NM II) bacteria. Immunodeficient mice, including SCID mice (deficient in T and B cells), SCIDbg mice (deficient in T, B, and NK cells), nude mice (deficient in T cells), muMT mice (deficient in B cells), bg mice (deficient in NK cells), mice deficient in tumor necrosis factor alpha (TNF-??/? mice), and mice deficient in gamma interferon (IFN-??/? mice), were compared for their responses to infection. SCID, SCIDbg, nude, and IFN-??/? mice showed high susceptibility to NM I, and TNF-??/? mice showed modest susceptibility. Disease caused by NM I in SCID, SCIDbg, and nude mice progressed slowly, while disease in IFN-??/? and TNF-??/? mice advanced rapidly. B- and NK-cell deficiencies did not enhance clinical disease development or alter bacterial clearance but did increase the severity of histopathological changes, particularly in the absence of B cells. Mice infected with NM II showed no apparent clinical disease, but T-cell-deficient mice had histopathological changes. These results suggest that T cells are critical for clearance of C. burnetii, either NM I or NM II, that IFN-? and TNF-? are essential for the early control of infection, and that B cells are important for the prevention of tissue damage. PMID:17438029

Andoh, Masako; Zhang, Guoquan; Russell-Lodrigue, Kasi E.; Shive, Heather R.; Weeks, Brad R.; Samuel, James E.



T cells are essential for bacterial clearance, and gamma interferon, tumor necrosis factor alpha, and B cells are crucial for disease development in Coxiella burnetii infection in mice.  


Coxiella burnetii, the etiological agent of Q fever, has two phase variants. Phase I has a complete lipopolysaccharide (LPS), is highly virulent, and causes Q fever in humans and pathology in experimental animals. Phase II lacks an LPS O side chain, is avirulent, and does not grow well in immunocompetent animals. To understand the pathogenicity of Q fever, we investigated the roles of immune components in animals infected with Nine Mile phase I (NM I) or Nine Mile phase II (NM II) bacteria. Immunodeficient mice, including SCID mice (deficient in T and B cells), SCIDbg mice (deficient in T, B, and NK cells), nude mice (deficient in T cells), muMT mice (deficient in B cells), bg mice (deficient in NK cells), mice deficient in tumor necrosis factor alpha (TNF-alpha(-/-) mice), and mice deficient in gamma interferon (IFN-gamma(-/-) mice), were compared for their responses to infection. SCID, SCIDbg, nude, and IFN-gamma(-/-) mice showed high susceptibility to NM I, and TNF-alpha(-/-) mice showed modest susceptibility. Disease caused by NM I in SCID, SCIDbg, and nude mice progressed slowly, while disease in IFN-gamma(-/-) and TNF-alpha(-/-) mice advanced rapidly. B- and NK-cell deficiencies did not enhance clinical disease development or alter bacterial clearance but did increase the severity of histopathological changes, particularly in the absence of B cells. Mice infected with NM II showed no apparent clinical disease, but T-cell-deficient mice had histopathological changes. These results suggest that T cells are critical for clearance of C. burnetii, either NM I or NM II, that IFN-gamma and TNF-alpha are essential for the early control of infection, and that B cells are important for the prevention of tissue damage. PMID:17438029

Andoh, Masako; Zhang, Guoquan; Russell-Lodrigue, Kasi E; Shive, Heather R; Weeks, Brad R; Samuel, James E



Distinctive selection mechanisms govern the T cell receptor repertoire of peripheral CD4-CD8- alpha/beta T cells  

PubMed Central

The T cell receptor (TCR) repertoire of CD4+ and CD8+ alpha/beta T cells is heavily influenced by positive and negative selection events that occur during T cell development in the thymus. The coreceptors CD4 and CD8 appear to be essential for this selection to occur. To gain insight into whether T cells that express TCR alpha/beta but lack either coreceptor (CD4- CD8- TCR alpha/beta or alpha/beta double- negative [DN] cells) are also subject to positive and negative selection, and whether selection can occur in the absence of coreceptors, we have performed an extensive immunogenetic analysis of the TCR V beta repertoire of alpha/beta DN cells in lymph nodes of normal mice. Our results show that alpha/beta DN cells appear to be unaffected by clonal deletion of V beta 5 and V beta 11 in I-E- expressing mice, and do not undergo deletion of V beta 6- and V beta 8.1-expressing T cells in Mls-1a-positive mice. They are also unaffected by positive selection of V beta 17a+ T cells in the context of I-Aq. The results suggest that most selection events require the participation of CD4 and CD8, while alpha/beta DN cells are unselected. This argues that most alpha/beta DN cells probably have never expressed CD4 or CD8. However, a unique form of repertoire selection occurs: enrichment of V beta 17a+ alpha/beta DN cells in I-E+ mice. This could be an instance of coreceptor-independent selection. PMID:1512537



Reactive oxygen species differentially affect T cell receptor-signaling pathways.  


Oxidative stress plays an important role in the induction of T lymphocyte hyporesponsiveness observed in several human pathologies including cancer, rheumatoid arthritis, leprosy, and AIDS. To investigate the molecular basis of oxidative stress-induced T cell hyporesponsiveness, we have developed an in vitro system in which T lymphocytes are rendered hyporesponsive by co-culture with oxygen radical-producing activated neutrophils. We have observed a direct correlation between the level of T cell hyporesponsiveness induced and the concentration of reactive oxygen species produced. Moreover, induction of T cell hyporesponsiveness is blocked by addition of N-acetyl cysteine, Mn(III)tetrakis(4-benzoic acid)porphyrin chloride, and catalase, confirming the critical role of oxidative stress in this system. The pattern of tyrosine-phosphorylated proteins was profoundly altered in hyporesponsive as compared with normal T cells. In hyporesponsive T cells, T cell receptor (TCR) ligation no longer induced phospholipase C-gamma1 activation and caused reduced Ca(2+) flux. In contrast, despite increased levels of ERK1/2 phosphorylation, TCR-dependent activation of mitogen-activated protein kinase ERK1/2 was unaltered in hyporesponsive T lymphocytes. A late TCR-signaling event such as caspase 3 activation was as well unaffected in hyporesponsive T lymphocytes. Our data indicate that TCR-signaling pathways are differentially affected by physiological levels of oxidative stress and would suggest that although "hyporesponsive" T cells have lost certain effector functions, they may have maintained or gained others. PMID:11916964

Cemerski, Saso; Cantagrel, Alain; Van Meerwijk, Joost P M; Romagnoli, Paola



Mathematical Model of Naive T Cell Division and Survival IL-7 Thresholds  

PubMed Central

We develop a mathematical model of the peripheral naive T cell population to study the change in human naive T cell numbers from birth to adulthood, incorporating thymic output and the availability of interleukin-7 (IL-7). The model is formulated as three ordinary differential equations: two describe T cell numbers, in a resting state and progressing through the cell cycle. The third is introduced to describe changes in IL-7 availability. Thymic output is a decreasing function of time, representative of the thymic atrophy observed in aging humans. Each T cell is assumed to possess two interleukin-7 receptor (IL-7R) signaling thresholds: a survival threshold and a second, higher, proliferation threshold. If the IL-7R signaling strength is below its survival threshold, a cell may undergo apoptosis. When the signaling strength is above the survival threshold, but below the proliferation threshold, the cell survives but does not divide. Signaling strength above the proliferation threshold enables entry into cell cycle. Assuming that individual cell thresholds are log-normally distributed, we derive population-average rates for apoptosis and entry into cell cycle. We have analyzed the adiabatic change in homeostasis as thymic output decreases. With a parameter set representative of a healthy individual, the model predicts a unique equilibrium number of T cells. In a parameter range representative of persistent viral or bacterial infection, where naive T cell cycle progression is impaired, a decrease in thymic output may result in the collapse of the naive T cell repertoire. PMID:24391638

Reynolds, Joseph; Coles, Mark; Lythe, Grant; Molina-París, Carmen



T cell–directed therapies: lessons learned and future prospects  

Microsoft Academic Search

Agents interfering with T cell function are therapeutic mainstays for various autoimmune diseases and for transplant approaches to organ failure. The understanding of T cell biology has blossomed since the development of most agents now in use. Here we discuss T cell–specific agents now in use, others recently added to the therapeutic armamentarium and promising agents being investigated in clinical

Eric H Liu; Richard M Siegel; David M Harlan; John J O'Shea



High Epitope Expression Levels Increase Competition between T Cells  

E-print Network

High Epitope Expression Levels Increase Competition between T Cells Almut Scherer, Marcel Salathe epitope ligand. We have developed an individual- based computer simulation model to study T cell competition. Our model shows that the expression level of foreign epitopes per APC determines whether T cell

Bonhoeffer, Sebastian


Deletion of Notch1 converts pro-T cells to dendritic cells and promotes thymic B cells by cell-extrinsic and cell-intrinsic mechanisms.  


Notch1 signaling is required for T cell development and has been implicated in fate decisions in the thymus. We showed that Notch1 deletion in progenitor T cells (pro-T cells) revealed their latent developmental potential toward becoming conventional and plasmacytoid dendritic cells. In addition, Notch1 deletion in pro-T cells resulted in large numbers of thymic B cells, previously explained by T-to-B cell fate conversion. Single-cell genotyping showed, however, that the majority of these thymic B cells arose from Notch1-sufficient cells by a cell-extrinsic pathway. Fate switching nevertheless exists for a subset of thymic B cells originating from Notch1-deleted pro-T cells. Chimeric mice lacking the Notch ligand delta-like 4 (Dll4) in thymus epithelium revealed an essential role for Dll4 in T cell development. Thus, Notch1-Dll4 signaling fortifies T cell commitment by suppressing non-T cell lineage potential in pro-T cells, and normal Notch1-driven T cell development repels excessive B cells in the thymus. PMID:19110448

Feyerabend, Thorsten B; Terszowski, Grzegorz; Tietz, Annette; Blum, Carmen; Luche, Hervé; Gossler, Achim; Gale, Nicholas W; Radtke, Freddy; Fehling, Hans Jörg; Rodewald, Hans-Reimer



CD8 T Cell Tolerance to a Tumor-Associated Self-Antigen Is Reversed by CD4 T Cells Engineered To Express the Same T Cell Receptor  

PubMed Central

Ag receptors used for cancer immunotherapy are often directed against tumor-associated Ags also expressed in normal tissues. Targeting of such Ags can result in unwanted autoimmune attack of normal tissues or induction of tolerance in therapeutic T cells. We used a murine model to study the phenotype and function of T cells redirected against the murine double minute protein 2 (MDM2), a tumor-associated Ag that shows low expression in many normal tissues. Transfer of MDM2-TCR–engineered T cells into bone marrow chimeric mice revealed that Ag recognition in hematopoietic tissues maintained T cell function, whereas presentation of MDM2 in nonhematopoietic tissues caused reduced effector function. TCR-engineered CD8+ T cells underwent rapid turnover, downmodulated CD8 expression, and lost cytotoxic function. We found that MDM2-TCR–engineered CD4+ T cells provided help and restored cytotoxic function of CD8+ T cells bearing the same TCR. Although the introduction of the CD8 coreceptor enhanced the ability of CD4+ T cells to recognize MDM2 in vitro, the improved self-antigen recognition abolished their ability to provide helper function in vivo. The data indicate that the same class I–restricted TCR responsible for Ag recognition and tolerance induction in CD8+ T cells can, in the absence of the CD8 coreceptor, elicit CD4 T cell help and partially reverse tolerance. Thus MHC class I–restricted CD4+ T cells may enhance the efficacy of therapeutic TCR-engineered CD8+ T cells and can be readily generated with the same TCR. PMID:25539815

Ghorashian, Sara; Veliça, Pedro; Chua, Ignatius; McNicol, Anne-Marie; Carpenter, Ben; Holler, Angelika; Nicholson, Emma; Ahmadi, Maryam; Zech, Mathias; Xue, Shao-An; Uckert, Wolfgang; Morris, Emma; Chakraverty, Ronjon



CD8 T cell tolerance to a tumor-associated self-antigen is reversed by CD4 T cells engineered to express the same T cell receptor.  


Ag receptors used for cancer immunotherapy are often directed against tumor-associated Ags also expressed in normal tissues. Targeting of such Ags can result in unwanted autoimmune attack of normal tissues or induction of tolerance in therapeutic T cells. We used a murine model to study the phenotype and function of T cells redirected against the murine double minute protein 2 (MDM2), a tumor-associated Ag that shows low expression in many normal tissues. Transfer of MDM2-TCR-engineered T cells into bone marrow chimeric mice revealed that Ag recognition in hematopoietic tissues maintained T cell function, whereas presentation of MDM2 in nonhematopoietic tissues caused reduced effector function. TCR-engineered CD8(+) T cells underwent rapid turnover, downmodulated CD8 expression, and lost cytotoxic function. We found that MDM2-TCR-engineered CD4(+) T cells provided help and restored cytotoxic function of CD8(+) T cells bearing the same TCR. Although the introduction of the CD8 coreceptor enhanced the ability of CD4(+) T cells to recognize MDM2 in vitro, the improved self-antigen recognition abolished their ability to provide helper function in vivo. The data indicate that the same class I-restricted TCR responsible for Ag recognition and tolerance induction in CD8(+) T cells can, in the absence of the CD8 coreceptor, elicit CD4 T cell help and partially reverse tolerance. Thus MHC class I-restricted CD4(+) T cells may enhance the efficacy of therapeutic TCR-engineered CD8(+) T cells and can be readily generated with the same TCR. PMID:25539815

Ghorashian, Sara; Veliça, Pedro; Chua, Ignatius; McNicol, Anne-Marie; Carpenter, Ben; Holler, Angelika; Nicholson, Emma; Ahmadi, Maryam; Zech, Mathias; Xue, Shao-An; Uckert, Wolfgang; Morris, Emma; Chakraverty, Ronjon; Stauss, Hans J



A Comparative Study of N-glycolylneuraminic Acid (Neu5Gc) and Cytotoxic T Cell (CT) Carbohydrate Expression in Normal and Dystrophin-Deficient Dog and Human Skeletal Muscle  

PubMed Central

The expression of N-glycolylneuraminic acid (Neu5Gc) and the cytotoxic T cell (CT) carbohydrate can impact the severity of muscular dystrophy arising from the loss of dystrophin in mdx mice. Here, we describe the expression of these two glycans in skeletal muscles of dogs and humans with or without dystrophin-deficiency. Neu5Gc expression was highly reduced (>95%) in muscle from normal golden retriever crosses (GR, n?=?3) and from golden retriever with muscular dystrophy (GRMD, n?=?5) dogs at multiple ages (3, 6 and 13 months) when compared to mouse muscle, however, overall sialic acid expression in GR and GRMD muscles remained high at all ages. Neu5Gc was expressed on only a minority of GRMD satellite cells, CD8+ T lymphocytes and macrophages. Human muscle from normal (no evident disease, n?=?3), Becker (BMD, n?=?3) and Duchenne (DMD, n?=?3) muscular dystrophy individuals had absent to very low Neu5Gc staining, but some punctate intracellular muscle staining was present in BMD and DMD muscles. The CT carbohydrate was localized to the neuromuscular junction in GR muscle, while GRMD muscles had increased expression on a subset of myofibers and macrophages. In humans, the CT carbohydrate was ectopically expressed on the sarcolemmal membrane of some BMD muscles, but not normal human or DMD muscles. These data are consistent with the notion that altered Neu5Gc and CT carbohydrate expression may modify disease severity resulting from dystrophin deficiency in dogs and humans. PMID:24505439

Martin, Paul T.; Golden, Bethannie; Okerblom, Jonathan; Camboni, Marybeth; Chandrasekharan, Kumaran; Xu, Rui; Varki, Ajit; Flanigan, Kevin M.; Kornegay, Joe N.



Increased Expression of Phosphorylated FADD in Anaplastic Large Cell and Other T-Cell Lymphomas  

PubMed Central

FAS-associated protein with death domain (FADD) is a major adaptor protein involved in extrinsic apoptosis, embryogenesis, and lymphocyte homeostasis. Although abnormalities of the FADD/death receptor apoptotic pathways have been established in tumorigenesis, fewer studies have analyzed the expression and role of phosphorylated FADD (pFADD). Our identification of FADD as a lymphoma-associated autoantigen in T-cell lymphoma patients raises the possibility that pFADD, with its correlation with cell cycle, may possess role(s) in human T-cell lymphoma development. This immunohistochemical study investigated pFADD protein expression in a range of normal tissues and lymphomas, particularly T-cell lymphomas that require improved therapies. Whereas pFADD was expressed only in scattered normal T cells, it was detected at high levels in T-cell lymphomas (eg, 84% anaplastic large cell lymphoma and 65% peripheral T cell lymphomas, not otherwise specified). The increased expression of pFADD supports further study of its clinical relevance and role in lymphomagenesis, highlighting phosphorylation of FADD as a potential therapeutic target. PMID:25232277

Patel, Suketu; Murphy, Derek; Haralambieva, Eugenia; Abdulla, Zainalabideen A; Wong, Kah Keng; Chen, Hong; Gould, Edith; Roncador, Giovanna; Hatton, Chris SR; Anderson, Amanda P; Banham, Alison H; Pulford, Karen



4-1BB Ligand Signaling to T Cells Limits T Cell Activation.  


4-1BB ligand (4-1BBL) and its receptor, 4-1BB, are both induced on T cells after activation, but little is known about the role of 4-1BBL. In this study we show that 4-1BBL can transmit signals that limit T cell effector activity under tolerogenic conditions. Cross-linking 4-1BBL inhibited IL-2 production in vitro, primarily with suboptimal TCR stimulation. Furthermore, naive 4-1BBL-deficient OT-II transgenic T cells displayed a greater conversion to effector T cells in vivo when responding to soluble OVA peptide in wild-type hosts, whereas development of Foxp3(+) regulatory T cells was not altered. A greater number of effector T cells also differentiated from naive wild-type OT-II T cells when transferred into 4-1BB-deficient hosts, suggesting that APC-derived 4-1BB is likely to trigger 4-1BBL. Indeed, effector T cells that could not express 4-1BBL accumulated in larger numbers in vitro when stimulated with 4-1BB-expressing mesenteric lymph node dendritic cells. 4-1BBL was expressed on T cells when Ag presentation was limiting, and 4-1BBL was aberrantly expressed at very high levels on T cells that could not express 4-1BB. Trans-ligation, Ab capture, and endocytosis experiments additionally showed that T cell-intrinsic 4-1BB regulated internalization of membrane 4-1BBL, implying that the strong induction of 4-1BB on T cells may counteract the suppressive function of 4-1BBL by limiting its availability. These data suggest that 4-1BBL expressed on T cells can restrain effector T cell development, creating a more favorable regulatory T cell to effector cell balance under tolerogenic conditions, and this may be particularly active in mucosal barrier tissues where 4-1BB-expressing regulatory dendritic cells present Ag. PMID:25404362

Eun, So-Young; Lee, Seung-Woo; Xu, Yanfei; Croft, Michael



T Cell Epitope Mapping of JC Polyoma Virus-Encoded Proteome Reveals Reduced T Cell Responses in HLA-DRB1*04:01+ Donors  

PubMed Central

JC polyomavirus (JCV) infection is highly prevalent and usually kept in a persistent state without clinical signs and symptoms. It is only during immunocompromise and especially impaired CD4+ T cell function in the brain, as seen in AIDS patients or natalizumab-treated multiple sclerosis patients, that JCV may cause progressive multifocal leukoencephalopathy (PML), an often life-threatening brain disease. Since CD4+ T cells likely play an important role in controlling JCV infection, we here describe the T cell response to JCV in a group of predominantly HLA-DR-heterozygotic healthy donors (HD) by using a series of overlapping 15-mer peptides spanning all JCV-encoded open reading frames. We identified immunodominant epitopes and compared T cell responses with anti-JCV VP1 antibody production and with the presence of urinary viral shedding. We observed positive JCV-specific T cell responses in 28.6% to 77.6%, humoral immune response in 42.6% to 89.4%, and urinary viral shedding in 36.4% to 45.5% of HD depending on the threshold. Four immunodominant peptides were mapped, and at least one immunogenic peptide per HLA-DRB1 allele was detected in DRB1*01+, DRB1*07+, DRB1*11+, DRB1*13+, DRB1*15+, and DRB1*03+ individuals. We show for the first time that JCV-specific T cell responses may be directed not only against JCV VP1 and large T antigen but also against all other JCV-encoded proteins. Heterozygotic DRB1*04:01+ individuals showed very low T cell responses to JCV together with normal anti-VP1 antibody levels and no urinary viral shedding, indicating a dominant-negative effect of this allele on global JCV-directed T cell responses. Our data are potentially relevant for the development of vaccines against JCV. PMID:23302880

Jel?i?, Ilijas; Aly, Lilian; Binder, Thomas M. C.; Jel?i?, Ivan; Bofill-Mas, Sílvia; Planas, Raquel; Demina, Victoria; Eiermann, Thomas H.; Weber, Thomas; Girones, Rosina; Sospedra, Mireia



Memory CD8+ T cell differentiation  

PubMed Central

In response to infection or effective vaccination, naive antigen-specific CD8+ T cells undergo a dramatic highly orchestrated activation process. Initial encounter with an appropriately activated antigen-presenting cell leads to blastogenesis and an exponential increase in antigen-specific CD8+ T cell numbers. Simultaneously, a dynamic differentiation process occurs, resulting in formation of both primary effector and long-lived memory cells. Current findings have emphasized the heterogeneity of effector and memory cell populations with the description of multiple cellular subsets based on phenotype, function, and anatomic location. Yet, only recently have we begun to dissect the underlying factors mediating the temporal control of the development of distinct effector and memory CD8+ T cell sublineages. In this review we will focus on the requirements for mounting an effective CD8+ T cell response and highlight the elements regulating the differentiation of effector and memory subsets. PMID:20146720

Obar, Joshua J.; Lefrançois, Leo



Liposome-coupled peptides induce long-lived memory CD8 T cells without CD4 T cells.  


CD8(+) T cells provide broad immunity to viruses, because they are able to recognize all types of viral proteins. Therefore, the development of vaccines capable of inducing long-lived memory CD8(+) T cells is desired to prevent diseases, especially those for which no vaccines currently exist. However, in designing CD8(+) T cell vaccines, the role of CD4(+) T cells in the induction and maintenance of memory CD8(+) T cells remains uncertain. In the present study, the necessity or not of CD4(+) T cells in the induction and maintenance of memory CD8(+) T cells was investigated in mice immunized with liposome-coupled CTL epitope peptides. When OVA-derived CTL epitope peptides were chemically coupled to the surfaces of liposomes and inoculated into mice, both primary and secondary CTL responses were successfully induced. The results were further confirmed in CD4(+) T cell-eliminated mice, suggesting that CD4(+) T cells were not required for the generation of memory CD8(+) T cells in the case of immunization with liposome-coupled peptides. Thus, surface-linked liposomal antigens, capable of inducing long-lived memory CD8(+) T cells without the contribution of CD4(+) T cells, might be applicable for the development of vaccines to prevent viral infection, especially for those viruses that evade humoral immunity by varying their surface proteins, such as influenza viruses, HIV, HCV, SARS coronaviruses, and Ebola viruses. PMID:21264321

Taneichi, Maiko; Tanaka, Yuriko; Kakiuchi, Terutaka; Uchida, Tetsuya



T Cell Receptor Signaling Kinetics Takes the Stage  

NSDL National Science Digital Library

It has been long surmised that the strength of stimulation of the T cell receptor (TCR) determines the robustness of TCR-mediated signaling and the magnitude of a T cell response. However, it is becoming evident that the signal from the TCR develops over time to approach its steady-state, affinity-determined maximal extent and that variations in this time have a substantial effect on the responsiveness of T cells. Here, I discuss data that show that the kinetics of signal propagation in various segments of the TCR signaling network can influence the spatiotemporal regulation of the effector functions of T cells and the quality of the T cell response.

Yuri Sykulev (Thomas Jefferson University; Department of Microbiology and Immunology and Kimmel Cancer Center REV)



Fas-Mediated Apoptosis Regulates the Composition of Peripheral ?? T Cell Repertoire by Constitutively Purging Out Double Negative T Cells  

PubMed Central

Background The Fas pathway is a major regulator of T cell homeostasis, however, the T cell population that is controlled by the Fas pathway in vivo is poorly defined. Although CD4 and CD8 single positive (SP) T cells are the two major T cell subsets in the periphery of wild type mice, the repertoire of mice bearing loss-of-function mutation in either Fas (lpr mice) or Fas ligand (gld mice) is predominated by CD4?CD8? double negative ?? T cells that also express B220 and generally referred to as B220+DN T cells. Despite extensive analysis, the basis of B220+DN T cell lymphoproliferation remains poorly understood. In this study we re-examined the issue of why T cell lymphoproliferation caused by gld mutation is predominated by B220+DN T cells. Methodology and Principal Findings We combined the following approaches to study this question: Gene transcript profiling, BrdU labeling, and apoptosis assays. Our results show that B220+DN T cells are proliferating and dying at exceptionally high rates than SP T cells in the steady state. The high proliferation rate is restricted to B220+DN T cells found in the gut epithelium whereas the high apoptosis rate occurred both in the gut epithelium and periphery. However, only in the periphery, apoptosis of B220+DN T cell is Fas-dependent. When the Fas pathway is genetically impaired, apoptosis of peripheral B220+DN T cells was reduced to a baseline level similar to that of SP T cells. Under these conditions of normalized apoptosis, B220+DN T cells progressively accumulate in the periphery, eventually resulting in B220+DN T cell lymphoproliferation. Conclusions/Significance The Fas pathway plays a critical role in regulating the tissue distribution of DN T cells through targeting and elimination of DN T cells from the periphery in the steady state. The results provide new insight into pathogenesis of DN T cell lymphoproliferation. PMID:18941614

Mohamood, Abdiaziz S.; Bargatze, Dylan; Xiao, Zuoxiang; Jie, Chunfa; Yagita, Hideo; Ruben, Dawn; Watson, Julie; Chakravarti, Shukti; Schneck, Jonathan P.; Hamad, Abdel Rahim A.



Induction of Mycobacterium tuberculosis-Specific Primary and Secondary T-Cell Responses in Interleukin-15-Deficient Mice  

PubMed Central

Several studies have provided evidence that interleukin-15 (IL-15) can enhance protective immune responses against Mycobacterium tuberculosis infection. However, the effects of IL-15 deficiency on the functionality of M. tuberculosis-specific CD4 and CD8 T cells are unknown. In this study, we investigated the generation and maintenance of effector and memory T-cell responses following M. tuberculosis infection of IL-15?/? mice. IL-15?/? mice had slightly higher bacterial numbers during chronic infection, which were accompanied by an increase in gamma interferon (IFN-?)-producing CD4 and CD8 T cells. There was no evidence of increased apoptosis or a defect in proliferation of CD8 effector T cells following M. tuberculosis infection. The induction of cytotoxic and IFN-? CD8 T-cell responses was normal in the absence of IL-15 signaling. The infiltration of CD4 and CD8 T cells into the lungs of “immune” IL-15?/? mice was delayed in response to M. tuberculosis challenge. These findings demonstrate that efficient effector CD4 and CD8 T cells can be developed following M. tuberculosis infection in the absence of IL-15 but that recall T-cell responses may be impaired. PMID:15845497

Lazarevic, Vanja; Yankura, David J.; Divito, Sherrie J.; Flynn, JoAnne L.



Overexpression of program death-1 in T cells has mild impact on allograft survival.  


Program death-1 (PD-1), an inhibitory receptor upregulated on T cells upon TCR stimulation, has been shown to attenuate a number of immune responses in vivo, including acute allograft rejection. We tested whether constitutive expression of PD-1 would further inhibit allograft rejection. To this end, we generated transgenic mice expressing T-cell-restricted PD-1 under the control of the Lck proximal promoter and CD2 locus control. PD-1 transgenic (PD-1-Tg) mice did not develop gross abnormalities of thymic development and displayed normal numbers of thymocyte subsets and peripheral T cells. In vitro, PD-1-Tg T cells had reduced proliferative and cytokine secretion capacity upon TCR stimulation and cross-linking of PD-1 resulted in diminished phosphorylation of protein kinase C-theta and Akt, as well as increased activation of the phosphate and tensin homolog. However, only T-cell responses to minor but not major mismatches were reduced in vitro. Similarly, PD-1-Tg mice exhibited prolonged survival of cardiac allografts only in mice transplanted with heart allografts expressing multiple minor mismatches and treated with suboptimal doses of cyclosporine A. We conclude that genetic engineering of T cells to express PD-1 constitutively has only a mild impact on allograft survival. PMID:18076633

Chen, Luqiu; Hussien, Yassir; Hwang, Kwang Woo; Wang, Ying; Zhou, Ping; Alegre, Maria-Luisa



?? T Cells in HIV Disease: Past, Present, and Future  

PubMed Central

Human immunodeficiency virus (HIV) type 1 dysregulates ?? T cells as part of an immune evasion mechanism. Nearly three decades of research defined the effects of HIV on ?? T cells and how this impacts disease. With highly effective antiretroviral therapy providing virus suppression and longer survival, we expected a return to normal for ?? T cells. This is not the case. Even in patients with CD4 T cell reconstitution, normal ?? T cell levels and function are not recovered. The durable damage to V?2 T cells is paralleled by defects in NK, CD8 T cells, and dendritic cells. Whether these consequences of HIV stem from similar or distinct mechanisms are not known and effective means for recovering the full range of cellular immunity have not been discovered. These unanswered questions receive too little attention in the overall program of efforts to cure HIV this disease. Approved drugs capable of increasing V?2 T cell function are being tested in clinical trials for cancer and hold promise for restoring normal function in patients with HIV disease. The impetus for conducting clinical trials will come from understanding the significance of ?? T cells in HIV disease and what might be gained from targeted immunotherapy. This review traces the history and current progress of AIDS-related research on ?? T cells. We emphasize the damage to ?? T cells that persists despite effective virus suppression. These chronic immune deficits may be linked to the comorbidities of AIDS (cancer, cardiovascular disease, metabolic disease, and others) and will hinder efforts to eradicate HIV by cytotoxic T or NK cell killing. Here, we focus on one subset of T cells that may be critical in the pathogenesis of HIV and an attractive target for new immune-based therapies.

Pauza, C. David; Poonia, Bhawna; Li, Haishan; Cairo, Cristiana; Chaudhry, Suchita



Engineering higher affinity T cell receptors using a T cell display system  

PubMed Central

The T cell receptor (TCR) determines the cellular response to antigens, which are presented on the surface of target cells in the form of a peptide bound to a product of the major histocompatibility complex (pepMHC). The response of the T cell depends on the affinity of the TCR for the pepMHC, yet many TCRs have been shown to be of low affinity, and some naturally occurring T cell responses are poor due to low affinities. Accordingly, engineering the TCR for increased affinity for pepMHC, particularly tumor-associated antigens, has become an increasingly desirable goal, especially with the advent of adoptive T cell therapies. For largely technical reasons, to date there have been only a handful of TCRs engineered in vitro for higher affinity using well established methods of protein engineering. Here we report the use of a T cell display system, using a retroviral vector, for generating a high affinity TCR from the mouse T cell clone 2C. The method relies on the display of the TCR, in its normal, signaling competent state, as a CD3 complex on the T cell surface. A library in the CDR3? of the 2C TCR was generated in the MSCV retroviral vector and transduced into a TCR-negative hybridoma. Selection of a high affinity, CD8-independent TCR was accomplished after only two rounds of flow cytometric sorting using the pepMHC SIYRYYGL/Kb (SIY/Kb). The selected TCR contained a sequence motif in the CDR3? with characteristics of several other TCRs previously selected by yeast display. In addition, it was possible to directly use the selected T cell hybridoma in functional assays without the need for sub-cloning, revealing that the selected TCR was capable of mediating CD8-independent activity. The method may be useful in the direct isolation and characterization of TCRs that could be used in therapies with adoptive transferred T cells. PMID:18854190

Chervin, Adam S.; Aggen, David H.; Raseman, John M.; Kranz, David M.



Girls homozygous for an IL-2–inducible T cell kinase mutation that leads to protein deficiency develop fatal EBV-associated lymphoproliferation  

PubMed Central

The fatal immune dysregulation that sometimes follows EBV infection in boys has been linked to mutations in two X chromosome–encoded genes, SLAM-associated protein (SAP) and X-linked inhibitor of apoptosis (XIAP). In this study we describe 2 girls from a consanguineous Turkish family who died after developing severe immune dysregulation and therapy-resistant EBV-positive B cell proliferation following EBV infection. SNP array–based genome-wide linkage analysis revealed IL-2–inducible T cell kinase (ITK) as a candidate gene for this immunodeficiency syndrome. Both girls harbored a homozygous missense mutation that led to substitution of a highly conserved residue (R335W) in the SH2 domain of ITK. Characteristics of ITK deficiency in mouse models, such as absence of NKT cells and high levels of eomesodermin in CD8+ cells, were seen in either one or both of the girls. Two lines of evidence suggested that R335W caused instability of the ITK protein. First, in silico modeling of the mutant protein predicted destabilization of the SH2 domain. Additionally, Western blot analysis revealed that, unlike wild-type ITK, the R335W mutant was nearly undetectable when expressed in 293 T cells. Our results suggest that ITK deficiency causes what we believe to be a novel immunodeficiency syndrome that leads to a fatal inadequate immune response to EBV. Because ITK deficiency resembles EBV-associated lymphoproliferative disorders in boys, we suggest that this molecular cause should be considered during diagnosis and treatment. PMID:19425169

Huck, Kirsten; Feyen, Oliver; Niehues, Tim; Rüschendorf, Franz; Hübner, Norbert; Laws, Hans-Jürgen; Telieps, Tanja; Knapp, Stefan; Wacker, Hans-Heinrich; Meindl, Alfons; Jumaa, Hassan; Borkhardt, Arndt



Polyclonal type II natural killer T cells require PLZF and SAP for their development and contribute to CpG-mediated antitumor response  

PubMed Central

CD1d-restricted natural killer T (NKT) cells are innate-like T cells with potent immunomodulatory function via rapid production of both Th1 and Th2 cytokines. NKT cells comprise well-characterized type I NKT cells, which can be detected by ?-galactosylceramide-loaded CD1d tetramers, and less-studied type II NKT cells, which do not recognize ?-galactosylceramide. Here we characterized type II NKT cells on a polyclonal level by using a J?18-deficient IL-4 reporter mouse model. This model allows us to track type II NTK cells by the GFP+TCR?+ phenotype in the thymus and liver. We found type II NKT cells, like type I NKT cells, exhibit an activated phenotype and are dependent on the transcriptional regulator promyelocytic leukemia zinc finger (PLZF) and the adaptor molecule signaling lymphocyte activation molecule-associated protein (SAP) for their development. Type II NKT cells are potently activated by ?-D-glucopyranosylceramide (?-GlcCer) but not sulfatide or phospholipids in a CD1d-dependent manner, with the stimulatory capacity of ?-GlcCer influenced by acyl chain length. Compared with type I NKT cells, type II NKT cells produce lower levels of IFN-? but comparable amounts of IL-13 in response to polyclonal T-cell receptor stimulation, suggesting they may play different roles in regulating immune responses. Furthermore, type II NKT cells can be activated by CpG oligodeoxynucletides to produce IFN-?, but not IL-4 or IL-13. Importantly, CpG-activated type II NKT cells contribute to the antitumor effect of CpG in the B16 melanoma model. Taken together, our data reveal the characteristics of polyclonal type II NKT cells and their potential role in antitumor immunotherapy. PMID:24550295

Zhao, Jie; Weng, Xiufang; Bagchi, Sreya; Wang, Chyung-Ru



Impaired T cell function in argininosuccinate synthetase deficiency.  


ASS1 is a cytosolic enzyme that plays a role in the conversion of citrulline to arginine. In human and mouse tissues, ASS1 protein is found in several components of the immune system, including the thymus and T cells. However, the role of ASS1 in these tissues remains to be defined. Considerable attention has been focused recently on the role of metabolism in T cell differentiation and function. Based on the expression of ASS1 in the immune system, we hypothesized that ASS1 deficiency would result in T cell defects. To evaluate this question, we characterized immune function in hypomorphic fold/fold mice. Analysis of splenic T cells by flow cytometry showed a marked reduction in T cell numbers with normal expression of activation surface markers. Gene therapy correction of liver ASS1 to enhance survival resulted in a partial recovery of splenic T cells for characterization. In vitro and in vivo studies demonstrated the persistence of the ASS1 enzyme defect in T cells and abnormal T cell differentiation and function. Overall, our work suggests that ASS1 plays a role in T cell function, and deficiency produces primary immune dysfunction. In addition, these data suggest that patients with ASS1 deficiency (citrullinemia type I) may have T cell dysfunction. PMID:25492936

Tarasenko, Tatyana N; Gomez-Rodriguez, Julio; McGuire, Peter J



Kinase Suppressor of Ras 1 Is Not Required for the Generation of Regulatory and Memory T Cells  

PubMed Central

The mammalian target of rapamycin (mTOR) kinase is a critical regulator of the differentiation of helper and regulatory CD4+ T cells, as well as memory CD8+ T cells. In this study, we investigated the role of the ERK signaling pathway in regulating mTOR activation in T cells. We showed that activation of ERK following TCR engagement is required for sustained mTOR complex 1 (mTORC1) activation. Absence of kinase suppressor of Ras 1 (KSR1), a scaffold protein of the ERK signaling pathway, or inhibition of ERK resulted in decreased mTORC1 activity following T cell activation. However, KSR1-deficient mice displayed normal regulatory CD4+ T cell development, as well as normal memory CD8+ T cell responses to LCMV and Listeria monocytogenes infection. These data indicate that despite its role in mTORC1 activation, KSR1 is not required in vivo for mTOR-dependent T cell differentiation. PMID:23431403

Le Borgne, Marie; Filbert, Erin L.; Shaw, Andrey S.



The receptor Ly108 functions as a SAP adaptor-dependent on-off switch for T cell help to B cells and NKT cell development.  


Humans and mice deficient in the adaptor protein SAP (Sh2d1a) have a major defect in humoral immunity, resulting from a lack of T cell help for B cells. The role of SAP in this process is incompletely understood. We found that deletion of receptor Ly108 (Slamf6) in CD4(+) T cells reversed the Sh2d1a(-/-) phenotype, eliminating the SAP requirement for germinal centers. This potent negative signaling by Ly108 required immunotyrosine switch motifs (ITSMs) and SHP-1 recruitment, resulting in high amounts of SHP-1 at the T cell:B cell synapse, limiting T cell:B cell adhesion. Ly108-negative signaling was important not only in CD4(+) T cells; we found that NKT cell differentiation was substantially restored in Slamf6(-/-)Sh2d1a(-/-) mice. The ability of SAP to regulate both positive and negative signals in T cells can explain the severity of SAP deficiency and highlights the importance of SAP and SHP-1 competition for Ly108 ITSM binding as a rheostat for the magnitude of T cell help to B cells. PMID:22683125

Kageyama, Robin; Cannons, Jennifer L; Zhao, Fang; Yusuf, Isharat; Lao, Christopher; Locci, Michela; Schwartzberg, Pamela L; Crotty, Shane



[Psychomotor development and its disorders: between normal and pathological development].  


This article discusses some aspects of psychomotor development and its disorders, with special emphasis on psychomotor retardation. Diagnostic classifications of psychomotor problems, such as DSM-IV and CIE-10, are referred to and their advantages and disadvantages are analyzed. The concept of normality as a synonym for the statistical mean in the context of psychomotor disorders is also analyzed in order to consider its dynamic and variability, thereby avoiding the normality/pathology opposition, while some issues, such as the social and cultural aspects, are highlighted, making it possible to rethink the universality and relativity of psychomotor development. PMID:24061024

Vericat, Agustina; Bibiana Orden, Alicia



The tumor suppressor Ikaros shapes the repertoire of notch target genes in T cells.  


The Notch signaling pathway is activated in many cell types, but its effects are cell type- and stage-specific. In the immune system, Notch activity is required for the differentiation of T cell progenitors, but it is reduced in more mature thymocytes, in which Notch is oncogenic. Studies based on single-gene models have suggested that the tumor suppressor protein Ikaros plays an important role in repressing the transcription of Notch target genes. We used genome-wide analyses, including chromatin immunoprecipitation sequencing, to identify genes controlled by Notch and Ikaros in gain- and loss-of-function experiments. We found that Ikaros bound to and directly repressed the expression of most genes that are activated by Notch. Specific deletion of Ikaros in thymocytes led to the persistent expression of Notch target genes that are essential for T cell maturation, as well as the rapid development of T cell leukemias in mice. Expression of Notch target genes that are normally silent in T cells, but are activated by Notch in other cell types, occurred in T cells of mice genetically deficient in Ikaros. We propose that Ikaros shapes the timing and repertoire of the Notch transcriptional response in T cells through widespread targeting of elements adjacent to Notch regulatory sequences. These results provide a molecular framework for understanding the regulation of tissue-specific and tumor-related Notch responses. PMID:24643801

Geimer Le Lay, Anne-Solen; Oravecz, Attila; Mastio, Jérôme; Jung, Claudia; Marchal, Patricia; Ebel, Claudine; Dembélé, Doulaye; Jost, Bernard; Le Gras, Stéphanie; Thibault, Christelle; Borggrefe, Tilman; Kastner, Philippe; Chan, Susan



Autoimmune melanocyte destruction is required for robust CD8+ memory T cell responses to mouse melanoma  

PubMed Central

A link between autoimmunity and improved antitumor immunity has long been recognized, although the exact mechanistic relationship between these two phenomena remains unclear. In the present study we have found that vitiligo, the autoimmune destruction of melanocytes, generates self antigen required for mounting persistent and protective memory CD8+ T cell responses to melanoma. Vitiligo developed in approximately 60% of mice that were depleted of regulatory CD4+ T cells and then subjected to surgical excision of large established B16 melanomas. Mice with vitiligo generated 10-fold larger populations of CD8+ memory T cells specific for shared melanoma/melanocyte antigens. CD8+ T cells in mice with vitiligo acquired phenotypic and functional characteristics of effector memory, suggesting that they were supported by ongoing antigen stimulation. Such responses were not generated in melanocyte-deficient mice, indicating a requirement for melanocyte destruction in maintaining CD8+ T cell immunity to melanoma. Vitiligo-associated memory CD8+ T cells provided durable tumor protection, were capable of mounting a rapid recall response to melanoma, and did not demonstrate phenotypic or functional signs of exhaustion even after many months of exposure to antigen. This work establishes melanocyte destruction as a key determinant of lasting melanoma-reactive immune responses, thus illustrating that immune-mediated destruction of normal tissues can perpetuate adaptive immune responses to cancer. PMID:21540555

Byrne, Katelyn T.; Côté, Anik L.; Zhang, Peisheng; Steinberg, Shannon M.; Guo, Yanxia; Allie, Rameeza; Zhang, Weijun; Ernstoff, Marc S.; Usherwood, Edward J.; Turk, Mary Jo



The Neutralization Breadth of HIV-1 Develops Incrementally over Four Years and Is Associated with CD4+ T Cell Decline and High Viral Load during Acute Infection ?  

PubMed Central

An understanding of how broadly neutralizing activity develops in HIV-1-infected individuals is needed to guide vaccine design and immunization strategies. Here we used a large panel of 44 HIV-1 envelope variants (subtypes A, B, and C) to evaluate the presence of broadly neutralizing antibodies in serum samples obtained 3 years after seroconversion from 40 women enrolled in the CAPRISA 002 acute infection cohort. Seven of 40 participants had serum antibodies that neutralized more than 40% of viruses tested and were considered to have neutralization breadth. Among the samples with breadth, CAP257 serum neutralized 82% (36/44 variants) of the panel, while CAP256 serum neutralized 77% (33/43 variants) of the panel. Analysis of longitudinal samples showed that breadth developed gradually starting from year 2, with the number of viruses neutralized as well as the antibody titer increasing over time. Interestingly, neutralization breadth peaked at 4 years postinfection, with no increase thereafter. The extent of cross-neutralizing activity correlated with CD4+ T cell decline, viral load, and CD4+ T cell count at 6 months postinfection but not at later time points, suggesting that early events set the stage for the development of breadth. However, in a multivariate analysis, CD4 decline was the major driver of this association, as viral load was not an independent predictor of breadth. Mapping of the epitopes targeted by cross-neutralizing antibodies revealed that in one individual these antibodies recognized the membrane-proximal external region (MPER), while in two other individuals, cross-neutralizing activity was adsorbed by monomeric gp120 and targeted epitopes that involved the N-linked glycan at position 332 in the C3 region. Serum antibodies from the other four participants targeted quaternary epitopes, at least 2 of which were PG9/16-like and depended on the N160 and/or L165 residue in the V2 region. These data indicate that fewer than 20% of HIV-1 subtype C-infected individuals develop antibodies with cross-neutralizing activity after 3 years of infection and that these antibodies target different regions of the HIV-1 envelope, including as yet uncharacterized epitopes. PMID:21389135

Gray, Elin S.; Madiga, Maphuti C.; Hermanus, Tandile; Moore, Penny L.; Wibmer, Constantinos Kurt; Tumba, Nancy L.; Werner, Lise; Mlisana, Koleka; Sibeko, Sengeziwe; Williamson, Carolyn; Abdool Karim, Salim S.; Morris, Lynn



TNF receptor associated factor 3 plays a key role in development and function of invariant natural killer T cells  

PubMed Central

TCR signaling is a prerequisite for early stage development of invariant natural killer T (iNKT) cells, whereas IL-15 signaling is required for expansion and maturation at later stages. In this study, we show that TNF receptor associated factor 3 (TRAF3) plays a critical role in the transition between these two distinct signaling pathways and developmental stages. TRAF3-deficient iNKT cells in CD4CreTRAF3flox/flox (T-TRAF3?/?) mice exhibit defective up-regulation of T-bet and CD122, two critical molecules for IL-15 signaling, and as a consequence, IL-15–mediated iNKT cell proliferation and survival are impaired. Consistently, development of iNKT cells in T-TRAF3?/? mice shows a major defect at developmental stages 2 and 3, but not stages 0 and 1. We further demonstrated that defective T-bet up-regulation occurring during the stage 1 to stage 2 transition results from reduced TCR signaling in TRAF3?/? iNKT cells. In addition, mature TRAF3?/? iNKT cells displayed defective cytokine responses upon TCR stimulation. Collectively, our results reveal that by modulating the relative strength of TCR signaling, TRAF3 is an important regulator of iNKT cell development and functions. PMID:23650438

Yi, Zuoan; Stunz, Laura L.



Stochastic processes in T-cell signaling  

E-print Network

T cells are orchestrators for adaptive immunity. Antigen recognition by T cells is mediated by the interactions between T-cell receptors (TCRs) and peptide-MHC (pMHC) molecules. How T cells can translate stimulatory external ...

Yang, Ming, Ph. D. Massachusetts Institute of Technology




PubMed Central

Anti-retroviral therapy (ART) has improved the quality of life for HIV+ individuals but efficacy requires strict adherence and treatment is not curative. Recently, the use of T cells as therapeutic agents have been in the spotlight in the settings of post-transplant opportunistic infections and cancer. Whether T cell therapy can be harnessed for treating HIV remains to be determined but there are a few studies that seek to answer that question. Infusion of ex vivo expanded HIV-specific T cells showed limited efficacy but no adverse events. Genetically modified T cells expressing CD4 chimeric antigen receptors (CAR) have recently been shown to have persistence that outperforms CARs used for cancers. Although the results have not yet been published for many clinical studies using T cells for HIV, preclinical studies and the clinical data that is available highlight the potential for T cell therapy to decrease or eliminate HIV patients’ dependency on ART. PMID:23557423

Lam, Sharon; Bollard, Catherine



Pinpointing when T cell costimulatory receptor CTLA-4 must be engaged to dampen diabetogenic T cells  

PubMed Central

Engagement of the T cell costimulatory receptor CTLA-4 can potently down-regulate an immune response. For example, in a T cell receptor transgenic mouse model of autoimmune diabetes, CTLA-4 interactions keep pancreatic islet-reactive T cells in check, evidenced by the finding that mAb blockade of CTLA-4 rapidly provokes diabetes in animals that would not normally succumb until many months later. Interestingly, this effect is only observed early in the course of disease, before insulitis is stably entrenched. Here, we have exploited a highly synchronous and easily manipulable transfer system to determine precisely when CTLA-4 must be engaged to check the diabetogenicity of islet-reactive T cells. Our results indicate that CTLA-4 interactions during initial priming of the T cells in the pancreatic lymph nodes are not determinant. Rather, the critical interactions occur when the T cells secondarily reencounter their antigen in the target organ, the pancreatic islets. In addition, we made use of CTLA-4-deficient mice to bolster our interpretation that CTLA-4 engagement has a dampening rather than an enhancing influence on diabetes progression. PMID:11035773

Lühder, Fred; Chambers, Cynthia; Allison, James P.; Benoist, Christophe; Mathis, Diane



PPAR? Negatively Regulates T Cell Activation to Prevent Follicular Helper T Cells and Germinal Center Formation  

PubMed Central

Peroxisome proliferator-activated receptor gamma (PPAR?) is a transcription factor that regulates lipid and glucose metabolism. Although studies of PPAR? ligands have demonstrated its regulatory functions in inflammation and adaptive immunity, its intrinsic role in T cells and autoimmunity has yet to be fully elucidated. Here we used CD4-PPAR?KO mice to investigate PPAR?-deficient T cells, which were hyper-reactive to produce higher levels of cytokines and exhibited greater proliferation than wild type T cells with increased ERK and AKT phosphorylation. Diminished expression of I?B?, Sirt1, and Foxo1, which are inhibitors of NF-?B, was observed in PPAR?-deficient T cells that were prone to produce all the signature cytokines under Th1, Th2, Th17, and Th9 skewing condition. Interestingly, 1-year-old CD4-PPAR?KO mice spontaneously developed moderate autoimmune phenotype by increased activated T cells, follicular helper T cells (TFH cells) and germinal center B cells with glomerular inflammation and enhanced autoantibody production. Sheep red blood cell immunization more induced TFH cells and germinal centers in CD4-PPAR?KO mice and the T cells showed increased of Bcl-6 and IL-21 expression suggesting its regulatory role in germinal center reaction. Collectively, these results suggest that PPAR? has a regulatory role for TFH cells and germinal center reaction to prevent autoimmunity. PMID:24921943

Park, Hong-Jai; Kim, Do-Hyun; Choi, Jin-Young; Kim, Won-Ju; Kim, Ji Yun; Senejani, Alireza G.; Hwang, Soo Seok; Kim, Lark Kyun; Tobiasova, Zuzana; Lee, Gap Ryol; Craft, Joseph; Bothwell, Alfred L. M.; Choi, Je-Min



Actin-Bundling Protein L-Plastin Regulates T Cell Activation  

PubMed Central

Engagement of T cell receptors induces actin rearrangements, which are critical for T cell activation. T cell responses require new actin polymerization, but the significance of higher order actin structures, such as microfilament bundles, is unknown. To determine the role of the actin-bundling protein leukocyte-plastin (L-plastin; LPL) in this process, T cells from LPL?/? mice were studied. LPL?/? T cells were markedly defective in TCR-mediated cytokine production and proliferation. LPL?/? T cells also spread inefficiently on surface with immobilized TCR ligands and formed smaller immunological synapses with APCs, likely due to defective formation of lamellipodia. LPL?/? mice showed delayed rejection of skin allografts after release from immunosuppression. Moreover, LPL?/? mice developed much less severe neurological symptoms in experimental autoimmune encephalomyelitis, which correlated with impaired T cell responses to antigen, manifested by reduced proliferation and production of IFN-? and IL-17. Thus, LPL-dependent actin bundling facilitates the formation of lamellipodia and normal immunological synapses, and thereby enables T cell activation. This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript. This version of the manuscript has not yet been copyedited or subjected to editorial proofreading by The JI; hence, it may differ from the final version published in The JI (online and in print). AAI (The JI) is not liable for errors or omissions in this author-produced version of the manuscript or in any version derived from it by the U.S. National Institutes of Health or any other third party. The final, citable version of record can be found at PMID:21076065

Wang, Chen; Morley, Sharon Celeste; Donermeyer, David; Peng, Ivan; Lee, Wyne P.; Devoss, Jason; Danilenko, Dimitry M.; Lin, Zhonghua; Zhang, Juan; Zhou, Jie; Allen, Paul M.; Brown, Eric J.



Involvement of Foxp3-expressing CD4+ CD25+ regulatory T cells in the development of tolerance induced by transforming growth factor-beta2-treated antigen-presenting cells.  


A growing body of evidence has shown that professional antigen-presenting cells (APC) treated with transforming growth factor-beta (TGF-beta) can induce a systemic antigen (Ag)-specific tolerance, similar to anterior chamber-associated immune deviation (ACAID). However, the exact mechanism for immune tolerance induced by TGF-beta-treated APC has not been elucidated. In this study, we showed that intravenous injection of ovalbumin (OVA)-pulsed APC treated with TGF-beta(2) induced a peripheral tolerance as evidenced by an impaired delayed-type hypersensitivity (DTH) response. CD4(+) T cells from mice receiving an intravenous injection of TGF-beta(2)-treated APC pulsed with OVA could adoptively transfer a specific tolerance to naïve mice. An increased frequency of FoxP3-expressing CD4(+) CD25(+) T cells was observed in mice with tolerance. CD4(+ )CD25(+) T cells from TGF-beta(2)-treated APC-injected mice produced a large amount of TGF-beta(1) and exhibited an in vitro antigen-specific suppressive activity. CD4(+) CD25(+) T cells from TGF-beta(2)-treated APC-injected mice were able to inhibit the antigen-specific DTH response significantly when adoptively transferred to naïve mice. These results indicate that FoxP3-expressing CD4(+) CD25(+) T cells might be actively involved in the development of tolerance induced by TGF-beta(2)-treated APC. PMID:18266851

Zhang, Haining; Yang, Peizeng; Zhou, Hongyan; Meng, Qianli; Huang, Xiangkun



Invariant natural killer T cells developing in the human fetus accumulate and mature in the small intestine.  


Invariant natural killer T (iNKT) cells are CD1d-restricted immunoregulatory lymphocytes that share characteristics of both the innate and adaptive immune systems. Although it has been reported that iNKT cells are present in the human fetal thymus, it is currently unknown how they distribute, differentiate, and function in fetal peripheral lymphoid and non-lymphoid organs. Here, we show that functional human fetal iNKT cells develop and differentiate in a tissue-specific manner during the second trimester. Fetal iNKT cells accumulated in the small intestine, where they gained a mature phenotype and mounted robust interferon (IFN)-? responses. In contrast, iNKT cells in the spleen and mesenteric lymph nodes were less frequently detected, less differentiated, mounted poor IFN-? responses, but proliferated vigorously upon stimulation with ?-galactosylceramide. These data demonstrate that fetal iNKT cells can differentiate and acquire potent effector functions in utero before the establishment of the commensal microflora. PMID:24646938

Loh, L; Ivarsson, M A; Michaëlsson, J; Sandberg, J K; Nixon, D F



Unbalanced Neonatal CD4+ T-Cell Immunity  

PubMed Central

In comparison to adults, newborns display a heightened susceptibility to pathogens and a propensity to develop allergic diseases. Particular properties of the neonatal immune system can account for this sensitivity. Indeed, a defect in developing protective Th1-type responses and a skewing toward Th2 immunity characterize today the neonatal T-cell immunity. Recently, new findings concerning Th17, regulatory helper T-cell, and follicular helper T-cell subsets in newborns have emerged. In some circumstances, development of effector inflammatory Th17-type responses can be induced in neonates, while differentiation in regulatory T-cells appears to be a default program of neonatal CD4+ T-cells. Poor antibody production, affinity maturation, and germinal center reaction in vaccinated neonates are correlated with a limiting expansion of TFH lymphocytes. We review herein the factors accounting for and the implications of the unbalanced neonatal helper T-cell immunity. PMID:25221551

Debock, Isabelle; Flamand, Véronique



Upholding the T cell immune-regulatory function of CD31 inhibits the formation of T/B immunological synapses in vitro and attenuates the development of experimental autoimmune arthritis in vivo.  


CD31, a trans-homophilic inhibitory receptor expressed on both T- and B-lymphocytes, drives the mutual detachment of interacting leukocytes. Intriguingly, T cell CD31 molecules relocate to the immunological synapse (IS), where the T and B cells establish a stable interaction. Here, we show that intact CD31 molecules, which are able to drive an inhibitory signal, are concentrated at the periphery of the IS but are excluded from the center of the IS. At this site, were the cells establish the closest contact, the CD31 molecules are cleaved, and most of the extracellular portion of the protein, including the trans-homophilic binding sites, is shed from the cell surface. T cells lacking CD31 trans-homophilic binding sites easily establish stable interactions with B cells; at the opposite, CD31 signaling agonists inhibit T/B IS formation as well as the ensuing helper T cell activation and function. Confocal microscopy and flow cytometry analysis of experimental T/B IS shows that the T cell inhibitory effects of CD31 agonists depend on SHP-2 signaling, which reduces the phosphorylation of ZAP70. The analysis of synovial tissue biopsies from patients affected by rheumatoid arthritis showed that T cell CD31 molecules are excluded from the center of the T/B cell synapses in vivo. Interestingly, the administration of CD31 agonists in vivo significantly attenuated the development of the clinical signs of collagen-induced arthritis in DBA1/J mice. Altogether, our data indicate that the T cell co-inhibitory receptor CD31 prevents the formation of functional T/B immunological synapses and that therapeutic strategies aimed at sustaining CD31 signaling will attenuate the development of autoimmune responses in vivo. PMID:25277651

Clement, Marc; Fornasa, Giulia; Loyau, Stéphane; Morvan, Marion; Andreata, Francesco; Guedj, Kevin; Khallou-Laschet, Jamila; Larghi, Paola; Le Roux, Delphine; Bismuth, Georges; Chiocchia, Gilles; Hivroz, Claire; Newman, Debra K; Nicoletti, Antonino; Caligiuri, Giuseppina



Development of ultra-super sensitive immunohistochemistry and its application to the etiological study of adult T-cell leukemia/lymphoma.  


Antigen retrieval (AR) and ultra-super sensitive immunohistochemistry (ultra-IHC) have been established for application to archival human pathology specimens. The original ultra-IHC was the ImmunoMax method or the catalyzed signal amplification system (ImmunoMax/CSA method), comprising the streptavidin-biotin complex (sABC) method and catalyzed reporter deposition (CARD) reaction with visualization of its deposition. By introducing procedures to diminish non-specific staining in the original ultra-IHC method, we developed the modified ImmunoMax/CSA method with AR heating sections in an AR solution (heating-AR). The heating-AR and modified ImmunoMax/CSA method visualized expression of the predominantly simple present form of HTLV-1 proviral DNA pX region p40Tax protein (Tax) in adult T-cell leukemia/lymphoma (ATLL) cells in archival pathology specimens in approximately 75% of cases. The simple present form of Tax detected exhibited a close relation with ATLL cell proliferation. We also established a new simplified CSA (nsCSA) system by replacing the sABC method with the secondary antibody- and horse radish peroxidase-labeled polymer reagent method, introducing the pretreatments blocking non-specific binding of secondary antibody reagent, and diminishing the diffusion of deposition in the CARD reaction. Combined with AR treating sections with proteinase K solution (enzymatic-AR), the nsCSA system visualized granular immunostaining of the complex present form of Tax in a small number of ATLL cells in most cases, presenting the possibility of etiological pathological diagnosis of ATLL and suggesting that the complex present form of Tax-positive ATLL cells were young cells derived from ATLL stem cells. The heating-AR and ultra-IHC detected physiological expression of the p53 protein and its probable phosphorylation by Tax in peripheral blood mononuclear cells of peripheral blood tissue specimens from HTLV-1 carriers, as well as physiological and pathological expression of the molecules involved with G1 phase progression and G1-S phase transition (E2F-1, E2F-4, DP-1, and cyclin E) in ATLL and peripheral T-cell lymphoma cells. The ultra-IHC with AR is useful for etiological pathological diagnosis of ATLL since HTLV-1 pathogenicity depends on that of Tax, and can be a useful tool for studies translating advanced molecular biology and pathology to human pathology. PMID:22685351

Hasui, Kazuhisa; Wang, Jia; Tanaka, Yuetsu; Izumo, Shuji; Eizuru, Yoshito; Matsuyama, Takami



Multiple Sclerosis and Regulatory T Cells  

PubMed Central

Multiple sclerosis (MS) is a complex genetic disease characterized by chronic inflammation of the central nervous system (CNS). The pathology of MS is largely attributed to autoreactive effector T cells that penetrate the blood-brain barrier and become activated within the CNS. As autoreactive T cells are present in the blood of both patients with MS and healthy individuals, other regulatory mechanisms exist to prevent autoreactive T cells from causing immune disorders. Active suppression by regulatory T (Treg) cells plays a key role in the control of self-antigen-reactive T cells and the induction of peripheral tolerance in vivo. In particular, the importance of antigen-specific Treg cells in conferring genetic resistance to organ specific autoimmunity and in limiting autoimmune tissue damage has been documented in many disease models including MS. We have found that the frequency of Tregs in MS patients is unchanged from controls, but their function measured in vitro may be diminished, correlating with impaired inhibitory activity in vivo. This review discusses the immunopathology of MS with particular focus given to regulatory T cells and their potential for the development of new therapies to treat this disease. PMID:18763026

Costantino, Cristina Maria; Hutton, Jonathon; Baecher-Allan, Clare; Hafler, David A.



Regulatory T cells as immunotherapy.  


Regulatory T cells (Tregs) suppress exuberant immune system activation and promote immunologic tolerance. Because Tregs modulate both innate and adaptive immunity, the biomedical community has developed an intense interest in using Tregs for immunotherapy. Conditions that require clinical tolerance to improve outcomes - autoimmune disease, solid organ transplantation, and hematopoietic stem cell transplantation - may benefit from Treg immunotherapy. Investigators have designed ex vivo strategies to isolate, preserve, expand, and infuse Tregs. Protocols to manipulate Treg populations in vivo have also been considered. Barriers to clinically feasible Treg immunotherapy include Treg stability, off-cell effects, and demonstration of cell preparation purity and potency. Clinical trials involving Treg adoptive transfer to treat graft versus host disease preliminarily demonstrated the safety and efficacy of Treg immunotherapy in humans. Future work will need to confirm the safety of Treg immunotherapy and establish the efficacy of specific Treg subsets for the treatment of immune-mediated disease. PMID:24575095

Singer, Benjamin D; King, Landon S; D'Alessio, Franco R



Aire-dependent production of XCL1 mediates medullary accumulation of thymic dendritic cells and contributes to regulatory T cell development.  


Dendritic cells (DCs) in the thymus (tDCs) are predominantly accumulated in the medulla and contribute to the establishment of self-tolerance. However, how the medullary accumulation of tDCs is regulated and involved in self-tolerance is unclear. We show that the chemokine receptor XCR1 is expressed by tDCs, whereas medullary thymic epithelial cells (mTECs) express the ligand XCL1. XCL1-deficient mice are defective in the medullary accumulation of tDCs and the thymic generation of naturally occurring regulatory T cells (nT reg cells). Thymocytes from XCL1-deficient mice elicit dacryoadenitis in nude mice. mTEC expression of XCL1, tDC medullary accumulation, and nT reg cell generation are diminished in Aire-deficient mice. These results indicate that the XCL1-mediated medullary accumulation of tDCs contributes to nT reg cell development and is regulated by Aire. PMID:21300913

Lei, Yu; Ripen, Adiratna Mat; Ishimaru, Naozumi; Ohigashi, Izumi; Nagasawa, Takashi; Jeker, Lukas T; Bösl, Michael R; Holländer, Georg A; Hayashi, Yoshio; Malefyt, Rene de Waal; Nitta, Takeshi; Takahama, Yousuke



Relationship between circulating levels of RANTES (regulated on activation, normal T-cell expressed, and secreted) and carotid plaque characteristics: the Atherosclerosis Risk in Communities (ARIC) Carotid MRI Study  

PubMed Central

Aims To assess the relationship between regulated on activation, normal T-cell expressed and secreted (RANTES) and carotid atherosclerotic plaque burden and plaque characteristics. Methods and results Gadolinium-enhanced magnetic resonance imaging (MRI) of the carotid artery was performed in 1901 participants from the Atherosclerosis Risk in Communities (ARIC) Study. Wall thickness and volume, lipid-core volume, and fibrous cap thickness (by MRI) and plasma RANTES levels (by ELISA) were measured. Regression analysis was performed to study the associations between MRI variables and RANTES. Among 1769 inclusive participants, multivariable regression analysis revealed that total wall volume [beta-coefficient (?) = 0.09, P = 0.008], maximum wall thickness (? = 0.08, P = 0.01), vessel wall area (? = 0.07, P = 0.02), mean minimum fibrous cap thickness (? = 0.11, P = 0.03), and high-sensitivity C-reactive protein (? = 0.09, P = 0.01) were positively associated with RANTES. Total lipid-core volume showed positive association in unadjusted models (? = 0.18, P = 0.02), but not in fully adjusted models (? = 0.13, P = 0.09). RANTES levels were highest in Caucasian females followed by Caucasian males, African-American females, and African-American males (P < 0.0001). Statin use attenuated the relationship between RANTES and measures of plaque burden. Conclusion Positive associations between RANTES and carotid wall thickness and lipid-core volume (in univariate analysis) suggest that higher RANTES levels may be associated with extent of carotid atherosclerosis and high-risk plaques. Associations between fibrous cap thickness and RANTES likely reflect the lower reliability estimate for fibrous cap measurements compared with wall volume or lipid-core volume measurements. Statin use may modify the association between RANTES and carotid atherosclerosis. Furthermore, RANTES levels vary by race. PMID:20943669

Virani, Salim S.; Nambi, Vijay; Hoogeveen, Ron; Wasserman, Bruce A.; Coresh, Josef; Gonzalez, Franklyn; Chambless, Lloyd E.; Mosley, Thomas H.; Boerwinkle, Eric; Ballantyne, Christie M.




PubMed Central

Porcine thymus grafts support robust murine and human thymopoiesis, generating a diverse T cell repertoire that is deleted of donor and host-reactive cells, achieving specific xenograft tolerance. Positive selection is mediated exclusively by the xenogeneic thymic MHC. While thymectomized, T cell-depleted normal mice usually remain healthy following xenogeneic thymic transplantation, thymus-grafted congenitally athymic mice frequently develop multiorgan autoimmunity. We investigated the etiology of this syndrome by adoptively transferring lymphocyte populations from fetal pig (FP) thymus (THY)-grafted (FPG) BALB/c nude mice to secondary BALB/c nude recipients. FPG nude mice generated normal numbers of CD25+Foxp3+CD4 T cells, but these cells lacked the capacity to block autoimmunity. Moreover, thymocytes and peripheral CD4+CD25? cells from FPG nude mice, but not those from normal mice, induced autoimmunity in nude recipients. Injection of thymic epithelial cells from normal BALB/c mice into FP THY grafts reduced autoimmunity and enhanced regulatory function of splenocytes. Our data implicate abnormalities in post-thymic maturation, expansion and/or survival of T cells positively selected by a xenogeneic MHC, as well as incomplete intrathymic deletion of thymocytes recognizing host tissue-specific antigens, in autoimmune pathogenesis. Regulatory cell function is enhanced and negative selection of host-specific thymocytes may potentially also be improved by co-implantation of recipient thymicepithelial cells in the thymus xenograft. PMID:19017953

Fudaba, Yasuhiro; Onoe, Takashi; Chittenden, Meredith; Shimizu, Akira; Shaffer, Juanita M.; Bronson, Roderick; Sykes, Megan



Retroviral transduction of peptide stimulated t cells can generate dual t cell receptor-expressing (bifunctional) t cells reactive with two defined antigens  

Microsoft Academic Search

BACKGROUND: Tumors and viruses have developed many mechanisms to evade the immune system, including down-regulation of target antigens and MHC molecules. These immune escape mechanisms may be able to be circumvented by adoptively transferring T cells engineered to express two different T cell receptors, each specific for a different antigen or MHC restriction molecule. METHODS: PBMC from the blood of

Alexander Langerman; Glenda G Callender; Michael I Nishimura



The receptor Ly108 functions as a SAP adaptor dependent on-off switch for T cell help to B cells and NKT cell development  

PubMed Central

Humans and mice deficient in the adaptor protein SAP (Sh2d1a) have a major defect in humoral immunity, due to lack of T cell help for B cells. The role of SAP in this process is incompletely understood. We found that deletion of receptor Ly108 (Slamf6) in CD4+ T cells reversed the Sh2d1a?/? phenotype, eliminating the SAP requirement for germinal centers. This potent negative signaling by Ly108 required immunotyrosine switch motifs (ITSMs) and SHP-1 recruitment, resulting in high amounts of SHP-1 at the T:B synapse, limiting T:B adhesion. Ly108 negative signaling was not only important in CD4+ T cells, as we found that NKT cell differentiation was substantially restored in Slamf6?/?Sh2d1a?/? mice. The ability of SAP to regulate both positive and negative signals in T cells can explain the severity of SAP-deficiency and highlights the importance of SAP and SHP-1 competition for Ly108 ITSM binding as a rheostat for the magnitude of T cell help to B cells. PMID:22683125

Kageyama, Robin; Cannons, Jennifer L.; Zhao, Fang; Yusuf, Isharat; Lao, Christopher; Locci, Michela; Schwartzberg, Pamela L.; Crotty, Shane



Primary intestinal posttransplant T-cell lymphoma.  


There have been only five reported cases of primary posttransplant T-cell lymphoma. We report the first case associated with the use of sirolimus (Rapamycin, Wyeth-Ayerst, Philadelphia, PA). The patient, receiving prednisone, cyclosporine, and sirolimus treatment, developed ascites, diarrhea, and weight loss 7 months after his second renal transplant. Tissue obtained at laparotomy established the diagnosis of primary T-cell lymphoma. Latent membrane protein-1 for Epstein-Barr virus was negative, but in-site hybridization test for Epstein-Barr-encoded RNA was positive. Despite aggressive chemotherapy, the patient died 8 months posttransplant. This is the sixth reported case of primary intestinal posttransplant T-cell lymphoma, but it is the first case associated with the use of sirolimus. The incidence of posttransplant lymphoproliferative disease in patients receiving sirolimus should be studied. PMID:12829924

Michael, J; Greenstein, S; Schechner, R; Tellis, V; Vasovic, L V; Ratech, H; Glicklich, D



Mechanics of T cell receptor gene rearrangement  

PubMed Central

Summary The four T cell receptor genes (Tcra, Tcrb, Tcrg, Tcrd) are assembled by V(D)J recombination according to distinct programs during intrathymic T cell development. These programs depend on genetic factors, including gene segment order and recombination signal sequences. They also depend on epigenetic factors. Regulated changes in chromatin structure, directed by enhancers and promoter, can modify the availability of recombination signal sequences to the RAG recombinase. Regulated changes in locus conformation may control the synapsis of distant recombination signal sequences, and regulated changes in subnuclear positioning may influence locus recombination events by unknown mechanisms. Together these influences may explain the ordered activation and inactivation of T cell receptor locus recombination events, and the phenomenon of Tcrb allelic exclusion. PMID:19362456

Krangel, Michael S.



T cell surface redox levels determine T cell reactivity and arthritis susceptibility.  


Rats and mice with a lower capacity to produce reactive oxygen species (ROS) because of allelic polymorphisms in the Ncf1 gene (which encodes neutrophil cytosolic factor 1) are more susceptible to develop severe arthritis. These data suggest that ROS are involved in regulating the immune response. We now show that the lower capacity to produce ROS is associated with an increased number of reduced thiol groups (-SH) on T cell membrane surfaces. Artificially increasing the number of reduced thiols on T cells from animals with arthritis-protective Ncf1 alleles by glutathione treatment lowered the threshold for T cell reactivity and enhanced proliferative responses in vitro and in vivo. Importantly, T cells from immunized congenic rats with an E3-derived Ncf1 allele (DA.Ncf1E3 rats) that cannot transfer arthritis to rats with an arthritis-associated Dark Agouti (DA)-derived mutated Ncf1 allele (DA.Ncf1DA rats) became arthritogenic after increasing cell surface thiol levels. This finding was confirmed by the reverse experiment, in which oxidized T cells from DA.Ncf1DA rats induced less severe arthritis compared with controls. Therefore, we conclude that ROS production as controlled by Ncf1 is important in regulating surface redox levels of T cells and thereby suppresses autoreactivity and arthritis development. PMID:16908843

Gelderman, Kyra A; Hultqvist, Malin; Holmberg, Jens; Olofsson, Peter; Holmdahl, Rikard



Discrete dynamic modeling of T cell survival signaling networks  

NASA Astrophysics Data System (ADS)

Biochemistry-based frameworks are often not applicable for the modeling of heterogeneous regulatory systems that are sparsely documented in terms of quantitative information. As an alternative, qualitative models assuming a small set of discrete states are gaining acceptance. This talk will present a discrete dynamic model of the signaling network responsible for the survival and long-term competence of cytotoxic T cells in the blood cancer T-LGL leukemia. We integrated the signaling pathways involved in normal T cell activation and the known deregulations of survival signaling in leukemic T-LGL, and formulated the regulation of each network element as a Boolean (logic) rule. Our model suggests that the persistence of two signals is sufficient to reproduce all known deregulations in leukemic T-LGL. It also indicates the nodes whose inactivity is necessary and sufficient for the reversal of the T-LGL state. We have experimentally validated several model predictions, including: (i) Inhibiting PDGF signaling induces apoptosis in leukemic T-LGL. (ii) Sphingosine kinase 1 and NF?B are essential for the long-term survival of T cells in T-LGL leukemia. (iii) T box expressed in T cells (T-bet) is constitutively activated in the T-LGL state. The model has identified potential therapeutic targets for T-LGL leukemia and can be used for generating long-term competent CTL necessary for tumor and cancer vaccine development. The success of this model, and of other discrete dynamic models, suggests that the organization of signaling networks has an determining role in their dynamics. Reference: R. Zhang, M. V. Shah, J. Yang, S. B. Nyland, X. Liu, J. K. Yun, R. Albert, T. P. Loughran, Jr., Network Model of Survival Signaling in LGL Leukemia, PNAS 105, 16308-16313 (2008).

Zhang, Ranran



Gamma delta T cells are needed for ocular immune privilege and corneal graft survival.  


It has been recognized for over a century that the anterior chamber of the eye is endowed with a remarkable immune privilege. One contributing component is the Ag-specific down-regulation of systemic delayed-type hypersensitivity (DTH) that is induced when Ags are introduced into the anterior chamber. This phenomenon, termed anterior chamber-associated immune deviation (ACAID), culminates in the generation of regulatory cells that inhibit the induction (afferent suppression) and expression (efferent suppression) of DTH. Since gamma delta T cells play a major role in other forms of immune regulation, we suspected they might contribute to the induction and expression of ACAID. Mice treated with anti-gamma delta Ab failed to develop ACAID following anterior chamber injection of either soluble Ag (OVA) or alloantigens (spleen cells). Additional experiments with knockout mice confirmed that mice lacking functional gamma delta T cells also fail to develop ACAID. Using a local adoptive transfer of DTH assay, we found that gamma delta T cells were required for the generation of regulatory T cells, but did not function as the efferent regulatory cells of ACAID. The importance of gamma delta T cells in corneal allograft survival was confirmed by blocking gamma delta T cells with GL3 Ab before corneal transplantation. While in vivo treatment with normal hamster serum had no effect on corneal graft survival, infusion of anti-gamma delta Ab resulted in a profound increase in corneal allograft rejection. Thus, gamma delta T cells are needed for sustaining at least one aspect of ocular immune privilege and for promoting corneal allograft survival. PMID:11254685

Skelsey, M E; Mellon, J; Niederkorn, J Y



T-Cell Signaling in HIV-1 Infection  

PubMed Central

HIV exploits the T-cell signaling network to gain access to downstream cellular components, which serves as effective tools to break the cellular barriers. Multiple host factors and their interaction with viral proteins contribute to the complexity of HIV-1 pathogenesis and disease progression. HIV-1 proteins gp120, Nef, Tat and Vpr alter the T-cell signaling pathways by activating multiple transcription factors including NF-?B, Sp1 and AP-1. HIV-1 evades the immune system by developing a multi-pronged strategy. Additionally, HIV-1 encoded proteins influence the apoptosis in the host cell favoring or blocking T-cell apoptosis. Thus, T-cell signaling hijacked by viral proteins accounts for both viral persistence and immune suppression during HIV-1 infection. Here, we summarize past and present studies on HIV-1 T-cell signaling with special focus on the possible role of T cells in facilitating viral infection and pathogenesis PMID:23986795

Abbas, Wasim; Herbein, Georges



T cell-specific inhibition of multiple apoptotic pathways blocks negative selection and causes autoimmunity  

PubMed Central

T cell self-tolerance is thought to involve peripheral tolerance and negative selection, involving apoptosis of autoreactive thymocytes. However, evidence supporting an essential role for negative selection is limited. Loss of Bim, a Bcl-2 BH3-only protein essential for thymocyte apoptosis, rarely results in autoimmunity on the C57BL/6 background. Mice with T cell-specific over-expression of Bcl-2, that blocks multiple BH3-only proteins, are also largely normal. The nuclear receptor Nur77, also implicated in negative selection, might function redundantly to promote apoptosis by associating with Bcl-2 and exposing its potentially pro-apoptotic BH3 domain. Here, we report that T cell-specific expression of a Bcl2 BH3 mutant transgene results in enhanced rescue of thymocytes from negative selection. Concomitantly, Treg development is increased. However, aged BH3 mutant mice progressively accumulate activated, autoreactive T cells, culminating in development of multi-organ autoimmunity and lethality. These data provide strong evidence that negative selection is crucial for establishing T cell tolerance. DOI: PMID:25182415

Burger, Megan L; Leung, Kenneth K; Bennett, Margaux J; Winoto, Astar



CD4+CD25+Foxp3+ Regulatory T Cells Depletion May Attenuate the Development of Silica-Induced Lung Fibrosis in Mice  

PubMed Central

Background Silicosis is an occupational lung disease caused by inhalation of silica dust characterized by lung inflammation and fibrosis. Previous study showed that Th1 and Th2 cytokines are involved in silicosis, but Th1/Th2 polarization during the development of silicosis is still a matter of debate. Regulatory T cells (Treg cells) represent a crucial role in modulation of immune homeostasis by regulating Th1/Th2 polarization, but their possible implication in silicosis remains to be explored. Methodology/Principal Findings To evaluate the implication of Treg cells in the development of silicosis, we generated the Treg-depleted mice model by administration of anti-CD25 mAbs and mice were exposed to silica by intratracheal instillation to establish experimental model of silica-induced lung fibrosis. The pathologic examinations show that the Treg-depleted mice are susceptive to severer inflammation in the early stage, with enhanced infiltration of inflammatory cells. Also, depletion of Treg cells causes a delay of the progress of silica-induced lung fibrosis in mice model. Further study of mRNA expression of cytokines reveals that depletion of Tregs leads to the increased production of Th1-cytokines and decreased production of Th2-cytokine. The Flow Cytometry and realtime PCR study show that Treg cells exert the modulation function both directly by expressing CTLA-4 at the inflammatory stage, and indirectly by secreting increasing amount of IL-10 and TGF-? during the fibrotic stage in silica-induced lung fibrosis. Conclusion/Significance Our study suggests that depletion of Tregs may attenuate the progress of silica-induced lung fibrosis and enhance Th1 response and decelerate Th1/Th2 balance toward a Th2 phenotype in silica-induced lung fibrosis. The regulatory function of Treg cells may depend on direct mechanism and indirect mechanism during the inflammatory stage of silicosis. PMID:21072213

Chen, Ying; Song, Laiyu; He, Qincheng; Chen, Jie



T Cells in Vascular Inflammatory Diseases  

PubMed Central

Inflammation of the human vasculature is a manifestation of many different diseases ranging from systemic autoimmune diseases to chronic inflammatory diseases, in which multiple types of immune cells are involved. For both autoimmune diseases and chronic inflammatory diseases several observations support a key role for T lymphocytes in these disease pathologies, but the underlying mechanisms are poorly understood. Previous studies in several autoimmune diseases have demonstrated a significant role for a specific subset of CD4+ T cells termed effector memory T (TEM) cells. This expanded population of TEM cells may contribute to tissue injury and disease progression. These cells exert multiple pro-inflammatory functions through the release of effector cytokines. Many of these cytokines have been detected in the inflammatory lesions and participate in the vasculitic reaction, contributing to recruitment of macrophages, neutrophils, dendritic cells, natural killer cells, B cells, and T cells. In addition, functional impairment of regulatory T cells paralyzes anti-inflammatory effects in vasculitic disorders. Interestingly, activation of TEM cells is uniquely dependent on the voltage-gated potassium Kv1.3 channel providing an anchor for specific drug targeting. In this review, we focus on the CD4+ T cells in the context of vascular inflammation and describe the evidence supporting the role of different T cell subsets in vascular inflammation. Selective targeting of pathogenic TEM cells might enable a more tailored therapeutic approach that avoids unwanted adverse side effects of generalized immunosuppression by modulating the effector functions of T cell responses to inhibit the development of vascular inflammation. PMID:25352848

Lintermans, Lucas L.; Stegeman, Coen A.; Heeringa, Peter; Abdulahad, Wayel H.



Effacing of the T Cell Compartment by Cardiac Transplantation in Infancy1  

Microsoft Academic Search

For cardiac transplantation in infants, T cells are depleted and the thymus is removed. These manipulations should cause profound defects in the T cell compartment. To test this concept, 20 subjects who underwent cardiac transplantation in infancy and healthy age-matched subjects were studied. The number of T cells in the blood was nearly normal in all subjects 1-10 years after

Brenda M. Ogle; Lori J. West; David J. Driscoll; Scott E. Strome; Raymund R. Razonable; Carlos V. Paya; Marilia Cascalho; Jeffrey L. Platt


Biomarkers in T cell therapy clinical trials  

PubMed Central

T cell therapy represents an emerging and promising modality for the treatment of both infectious disease and cancer. Data from recent clinical trials have highlighted the potential for this therapeutic modality to effect potent anti-tumor activity. Biomarkers, operationally defined as biological parameters measured from patients that provide information about treatment impact, play a central role in the development of novel therapeutic agents. In the absence of information about primary clinical endpoints, biomarkers can provide critical insights that allow investigators to guide the clinical development of the candidate product. In the context of cell therapy trials, the definition of biomarkers can be extended to include a description of parameters of the cell product that are important for product bioactivity. This review will focus on biomarker studies as they relate to T cell therapy trials, and more specifically: i. An overview and description of categories and classes of biomarkers that are specifically relevant to T cell therapy trials, and ii. Insights into future directions and challenges for the appropriate development of biomarkers to evaluate both product bioactivity and treatment efficacy of T cell therapy trials. PMID:21851646



The role of T-cell subsets in the response to anti-CD3 monoclonal antibodies.  


Administration of monoclonal antibodies (mAb) to CD3 elicits an immune response to the mAb and an acute toxic syndrome that has been attributed to the release of cytokines from activated T cells. To clarify the cellular basis for these effects, we used anti-lymphocyte mAb to deplete selected T-cell subsets from BALB/c mice prior to administration of anti-CD3. In our first series of experiments, anti-CD4 repeatedly blocked the immune response to anti-CD3, but did not prevent severe toxicity. This observation suggested that other T-cell subsets might contribute to anti-CD3 induced toxicity. Therefore, we treated mice with mAb to CD8 as well as mAb to CD4 prior to administration of anti-CD3. Despite depletion of > 95% of CD8+ and CD4+ T cells, toxicity was not suppressed. This finding cast doubt on the belief that toxicity is due to activation of either CD4+ or CD8+ T cells by anti-CD3. Therefore, we assessed the role of thymocytes (which are not deleted by the mAb) and gamma delta + T cells. Thymectomy did not prevent toxicity in CD4/CD8-depleted mice, demonstrating that thymocytes are not responsible for toxicity. Anti-alpha beta TCR mAb produced a toxic reaction similar to anti-CD3 whereas anti-gamma delta TCR mAb did not, suggesting that gamma delta+ T cells are not the source of toxic cytokines. In addition, we proved that anti-CD3-induced toxicity was not due to direct effects on macrophages or to other nonspecific factors associated with the hamster mAb. These findings imply that a few residual mature T cells in mice treated with mAb to CD4 and CD8 are sufficient for the full expression of the anti-CD3-induced toxic syndrome. To confirm that both CD4+ and CD8+ T cells can mediate toxicity, we showed that:(i) SCID mice, which normally do not develop anti-CD3-induced toxicity, can be rendered susceptible by reconstitution with purified CD4+ T cells; and (ii) CD4-knockout mice that lack CD4+ T cells but have normal CD8+ T cells are susceptible to anti-CD3-induced toxicity. These findings establish that both CD4+ and CD8+ cells contribute to the toxic effects of anti-CD3, and that relatively few cells are required to mediate the full effect. PMID:1360341

Finck, B K; Yung, C M; Carteron, N L; Wofsy, D



Utilizing Regulatory T Cells Against Rheumatoid Arthritis  

PubMed Central

Regulatory T (Treg) cells are essential for normal immune surveillance systems, and their dysfunction leads to development of diseases, such as autoimmune disorders. CD4+CD25+ Treg cells are well-known suppressive cells, which express the transcription factor Foxp3, are indispensable for the maintenance of immune self-tolerance and homeostasis by suppressing aberrant or excessive immune response. Other Foxp3? Treg cells include Tr1, Th3, CD8+CD28?/?, and Qa1-restricted T cells; however, the contribution of these Treg cells to self-tolerance, immune homeostasis as well as preventing autoimmunity is not well defined. Here, we discuss the phenotypes and function of Foxp3+ Treg cells and the potential use of such Treg cells against rheumatoid arthritis (RA). Of note, even though most expanded populations of Foxp3+ Treg cells exhibit suppressive activity, tissue-associated or antigen-specific Treg cells appear superior in suppressing local autoimmune disorders such as RA. In addition, utilizing tissue-associated Foxp3+ Treg cells from stem cells may stable Foxp3 expression and avoid induction of a potentially detrimental systemic immunosuppression. PMID:25152867

Haque, Mohammad; Fino, Kristin; Lei, Fengyang; Xiong, Xiaofang; Song, Jianxun



The development of autoimmune features in aging mice is closely associated with alterations of the peripheral CD4? T-cell compartment.  


Some signs of potential autoimmunity, such as the appearance of antinuclear antibodies (ANAs) become prevalent with age. In most cases, elderly people with ANAs remain healthy. Here, we investigated whether the same holds true for inbred strains of mice. Indeed, we show that most mice of the C57BL/6 (B6) strain spontaneously produced IgG ANA at 8-12 months of age, showed IgM deposition in kidneys and lymphocyte infiltrates in submandibular salivary glands. Despite all of this, the mice remained healthy. ANA production is likely CD4(+) T-cell dependent, since old (40-50 weeks of age) B6 mice deficient for MHC class II do not produce IgG ANAs. BM chimeras showed that ANA production was not determined by age-related changes in radiosensitive, hematopoietic progenitor cells, and that the CD4(+) T cells that promote ANA production were radioresistant. Thymectomy of B6 mice at 5 weeks of age led to premature alterations in T-cell homeostasis and ANA production, by 15 weeks of age, similar to that in old mice. Our findings suggest that a disturbed T-cell homeostasis may drive the onset of some autoimmune features. PMID:25044476

Nusser, Anja; Nuber, Natko; Wirz, Oliver F; Rolink, Hannie; Andersson, Jan; Rolink, Antonius



C7a, a Biphosphinic Cyclopalladated Compound, Efficiently Controls the Development of a Patient-Derived Xenograft Model of Adult T Cell Leukemia/Lymphoma  

PubMed Central

Adult T-cell leukemia/lymphoma (ATLL) is a highly aggressive disease that occurs in individuals infected with the human T lymphotropic virus type 1 (HTLV-1). Patients with aggressive ATLL have a poor prognosis because the leukemic cells are resistant to conventional chemotherapy. We have investigated the therapeutic efficacy of a biphosphinic cyclopalladated complex {Pd2 [S(?)C2, N-dmpa]2 (?-dppe)Cl2}, termed C7a, in a patient-derived xenograft model of ATLL, and investigated the mechanism of C7a action in HTLV-1-positive and negative transformed T cell lines in vitro. In vivo survival studies in immunocompromised mice inoculated with human RV-ATL cells and intraperitoneally treated with C7a led to significantly increased survival of the treated mice. We investigated the mechanism of C7a activity in vitro and found that it induced mitochondrial release of cytochrome c, caspase activation, nuclear condensation and DNA degradation. These results suggest that C7a triggers apoptotic cell death in both HTLV-1 infected and uninfected human transformed T-cell lines. Significantly, C7a was not cytotoxic to peripheral blood mononuclear cells (PBMC) from healthy donors and HTLV-1-infected individuals. C7a inhibited more than 60% of the ex vivo spontaneous proliferation of PBMC from HTLV-1-infected individuals. These results support a potential therapeutic role for C7a in both ATLL and HTLV-1-negative T-cell lymphomas. PMID:21994769

Guimaraes-Correa, Ana B.; Crawford, Lindsey B.; Figueiredo, Carlos R.; Gimenes, Karina P.; Pinto, Lorena A.; Rios Grassi, Maria Fernanda; Feuer, Gerold; Travassos, Luiz R.; Caires, Antonio C.F.; Rodrigues, Elaine G.; Marriott, Susan J.



The Transcriptional Repressor Gfi1 Affects Development of Early, Uncommitted c-KitT Cell Progenitors and CD4\\/CD8 Lineage Decision in the Thymus  

Microsoft Academic Search

In the thymus, several steps of proliferative expansion and selection coordinate the maturation of precursors into antigen-specific T cells. Here we identify the transcriptional repressor Gfi1 as an important regulator of this maturation process. Mice lacking Gfi1 show reduced thymic cellularity due to an increased cell death rate, lack of proliferation, and a differentiation block in the very early uncommitted

Raif Yücel; Holger Karsunky; Ludger Klein-Hitpass; Tarik Möröy


CD69 overexpression by human T-cell leukemia virus type 1 Tax transactivation.  


Human T-cell leukemia virus type 1 (HTLV-1) infection is associated with the development of adult T-cell leukemia (ATL) and various inflammatory diseases. CD69 is a marker of early activation of lymphocytes. We investigated the effects of HTLV-1 infection on the expression of CD69. The CD69 gene was upregulated in all viral protein Tax-expressing HTLV-1-transformed T-cell lines, except MT-2 and peripheral blood mononuclear cells from patients with ATL compared with uninfected T-cell line, Tax-negative ATL-derived T-cell lines and normal peripheral blood mononuclear cells. Flow cytometric analysis and immunohistochemical analysis confirmed the enhanced expression of CD69 in HTLV-1-transformed T-cell lines and in ATL cells in lymph nodes and skin lesions, and its absence in MT-2 and peripheral blood mononuclear cells. CD69 expression was induced following infection of human T-cell line with HTLV-1, and specifically by Tax. Tax transcriptionally activated CD69 gene through both nuclear factor-?B and cyclic adenosine 3',5'-monophosphate response element-binding protein signaling pathways. Detailed analysis of the CD69 promoter indicated that the Tax-induced expression of CD69 was regulated by multiple cis-acting elements and by the interplay of transcription factors of the nuclear factor-?B, early growth response and cyclic adenosine 3',5'-monophosphate response element-binding protein families. The lack of CD69 expression in MT-2 is due to epigenetic mechanism involving deacetylation, but not methylation. We conclude that CD69 is a Tax-regulated gene, and its regulation by Tax may play a role in cellular activation and HTLV-1-induced disease pathogenesis. PMID:23507197

Ishikawa, Chie; Kawakami, Hirochika; Uchihara, Jun-Nosuke; Senba, Masachika; Mori, Naoki



Host T Cells Affect Donor T Cell Engraftment and Graft-versus-Host Disease after Reduced-Intensity Hematopoietic Stem Cell Transplantation  

PubMed Central

Mixed chimerism in the T cell compartment (MCT) after reduced-intensity stem cell transplantation (RIST) may influence immune repopulation with alloreactive donor T cells. We examined effects of host T cell numbers on donor T cell engraftment and recovery and on acute graft-versus-host disease (GVHD) in a relatively homogeneous patient population with respect to residual host T cells through quantified immune depletion prior to RIST and to donor T cells by setting the allograft T cell dose of 1×105 CD3+ cells/kg. In this setting, two patterns of early donor T cell engraftment could be distinguished by Day +42: (1) early and complete donor chimerism in the T cell compartment (FDCT) and (2) persistent MCT. FDCT was associated with lower residual host CD8+ T cell counts prior to transplant and acute GVHD. With persistent MCT, subsequent development of acute GVHD could be predicted by the direction of change in T cell donor chimerism after donor lymphocyte infusion, and no acute GVHD occurred until FDCT was established. MCT did not affect recovery of donor T cell counts. These observations suggest that the relative number and alloreactivity of donor and host T cells are more important than the absolute allograft T cell dose in determining donor engraftment and acute GVHD after RIST. PMID:17697964

Hardy, Nancy M.; Hakim, Frances; Steinberg, Seth M.; Krumlauf, Michael; Cvitkovic, Romana; Babb, Rebecca; Odom, Jeanne; Fowler, Daniel H.; Gress, Ronald E.; Bishop, Michael R.



HEB-Deficient T-Cell Precursors Lose T-Cell Potential and Adopt an Alternative Pathway of Differentiation? †  

PubMed Central

Early thymocytes possess multilineage potential, which is progressively restricted as cells transit through the double-negative stages of T-cell development. DN1 cells retain the ability to become natural killer cells, dendritic cells, B cells, and myeloid cells as well as T cells, but these options are lost by the DN3 stage. The Notch1 signaling pathway is indispensable for initiation of the T-cell lineage and inhibitory for the B-cell lineage, but the regulatory mechanisms by which the T-cell fate is locked in are largely undefined. Previously, we discovered that the E-protein transcription factor HEBAlt promoted T-cell specification. Here, we report that HEB?/? T-cell precursors have compromised Notch1 function and lose T-cell potential. Moreover, reconstituting HEB?/? precursors with Notch1 activity enforced fidelity to the T-cell fate. However, instead of becoming B cells, HEB?/? DN3 cells adopted a DN1-like phenotype and could be induced to differentiate into thymic NK cells. HEB?/? DN1-like cells retained GATA3 and Id2 expression but had lower levels of the Bcl11b gene, a Notch target gene. Therefore, our studies have revealed a new set of interactions between HEB, Notch1, and GATA3 that regulate the T-cell fate choice in developing thymocytes. PMID:21189289

Braunstein, Marsela; Anderson, Michele K.



High T-cell response to human cytomegalovirus induces chemokine-mediated endothelial cell damage  

PubMed Central

Human cytomegalovirus (CMV) infection has been linked to inflammatory diseases that involve vascular endothelial damage, including vascular disease and chronic transplant rejection. We previously reported that the host CD4+ T-cell response to CMV antigen presented by endothelial cells can produce interferon-? and tumor necrosis factor-? at levels sufficient to drive induction of fractalkine, a key marker of inflammation, in endothelial cells. In this work, we report that donors with high frequencies of antigen-specific T cells to CMV (high responders) induce higher levels of activation-associated chemokines such as fractalkine, RANTES (regulated on activation, normal T cell expressed and secreted), and macrophage inflammatory protein-1?, together with cell-adhesion markers in endothelial cells compared with donors with low levels of CMV-specific T cells (low responders). High-responder cultures had higher levels of leukocyte recruitment and adherence to the endothelial monolayers associated with progressive damage and loss of the endothelial cells. These processes that led to endothelial destruction only required viral antigen and did not require infectious virus. Our findings further support that CMV may represent one member of a class of persistent pathogens in which a high antigen-specific T-cell response defines an important risk factor for development of chronic inflammation and endothelial cell injury. PMID:17519388

Bolovan-Fritts, Cynthia A.; Trout, Rodney N.



Human Hepatic Stellate Cells Inhibit T cell Response through B7-H1 Pathway  

PubMed Central

Background The liver is an immunological privileged organ – liver allografts are accepted across major histocompatibility complex barriers in many species; however, hepatocyte transplants are acutely rejected, suggesting a role for liver non-parenchymal cells in regulating the immune response. We have shown potent immune regulatory activity of hepatic stellate cells (HSCs) in mice. The aim of this study was to examine the immune regulatory activity of human HSCs. Methods HSCs were isolated from normal human livers for analyses of their impact on T cell response. Results HSCs expressed low HLA-DR and co-stimulatory molecules CD40, CD80, but constitutively expressed high levels of CD54. IFN? stimulated HSCs to express B7-H1 in a dose dependent manner, and produce the suppressive cytokines IL-6, IL-10 and TGF?, but not affect expression of HLA-DR, CD40 and CD80. Human HSCs did not stimulate allogeneic T cell proliferative response, indicating they are not professional APC. HSCs markedly inhibited T cell response elicited by either allogeneic APC or CD3/CD28 beads, which was associated with increases in activated CD4 and CD8 T cell apoptosis. Addition of anti-B7-H1 blocking Ab significantly reversed the inhibitory effect. Conclusions Human HSCs demonstrate potent immune regulatory activity via B7-H1-mediated induction of apoptosis in activated T cells. Understanding of the involved mechanisms may lead to development of novel therapeutic approaches for treatment of liver diseases. PMID:23756770

Charles, Ronald; Chou, Hong-Shiue; Wang, Lianfu; Fung, John J.; Lu, Lina; Qian, Shiguang



Characterizing T Cells in SCID Patients Presenting with Reactive or Residual T Lymphocytes  

PubMed Central

Introduction. Patients with severe combined immunodeficiency (SCID) may present with residual circulating T cells. While all cells are functionally deficient, resulting in high susceptibility to infections, only some of these cells are causing autoimmune symptoms. Methods. Here we compared T-cell functions including the number of circulating CD3+ T cells, in vitro responses to mitogens, T-cell receptor (TCR) repertoire, TCR excision circles (TREC) levels, and regulatory T cells (Tregs) enumeration in several immunodeficinecy subtypes, clinically presenting with nonreactive residual cells (MHC-II deficiency) or reactive cells. The latter includes patients with autoreactive clonal expanded T cell and patients with alloreactive transplacentally maternal T cells. Results. MHC-II deficient patients had slightly reduced T-cell function, normal TRECs, TCR repertoires, and normal Tregs enumeration. In contrast, patients with reactive T cells exhibited poor T-cell differentiation and activity. While the autoreactive cells displayed significantly reduced Tregs numbers, the alloreactive transplacentally acquired maternal lymphocytes had high functional Tregs. Conclusion. SCID patients presenting with circulating T cells show different patterns of T-cell activity and regulatory T cells enumeration that dictates the immunodeficient and autoimmune manifestations. We suggest that a high-tolerance capacity of the alloreactive transplacentally acquired maternal lymphocytes represents a toleration advantage, yet still associated with severe immunodeficiency. PMID:23243423

Lev, Atar; Simon, Amos J.; Trakhtenbrot, Luba; Goldstein, Itamar; Nagar, Meital; Stepensky, Polina; Rechavi, Gideon; Amariglio, Ninette; Somech, Raz



B and T cell screen  


Direct immunofluorescence; E-rosetting; T and B lymphocyte assays; B and T lymphocyte assays ... to distinguish between T and B cells. The E-rosetting test identifies T cells and direct immunofluorescence ...


?2 integrins are required for skin homing of primed T cells but not for priming naive T cells  

PubMed Central

?2 integrins are of critical importance for leukocyte extravasation through vascular endothelia and for T cell activation. To elucidate the role of ?2 integrins in T cell–mediated immune responses, allergic contact dermatitis (ACD), irritant dermatitis, and delayed-type hypersensitivity (DTH) were assessed in mice lacking the ?2 integrin subunit, CD18. ACD and DTH responses, but not edema formation, were severely suppressed in CD18–/– mice. Extravasation of CD18–/– T cells into eczematous skin lesions was greatly impaired, whereas migration of Langerhans cell precursors and dendritic cells was normal in CD18–/– mice. CD18–/–lymph nodes (LNs) contained an abnormal population of CD3–CD44high lymphocytes and showed evidence of widespread T cell activation. T cells from regional LNs of sensitized CD18–/– mice proliferated in response to hapten challenge, and subcutaneous injection of sensitized syngeneic LN cells directly into ears of hapten-challenged naive recipients restored the defective ACD in CD18–/– mice, suggesting that CD18 is not required for priming of naive T cells but is indispensable for T cell extravasation. Thus, a dysfunction of T cells, in addition to granulocytes, may contribute to the pathophysiology of leukocyte adhesion deficiency type I, which arises from mutations in the human CD18 gene. PMID:11805130

Grabbe, Stephan; Varga, Georg; Beissert, Stefan; Steinert, Meike; Pendl, Gunther; Seeliger, Stephan; Bloch, Wilhelm; Peters, Thorsten; Schwarz, Thomas; Sunderkötter, Cord; Scharffetter-Kochanek, Karin



ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. Black-Right-Pointing-Pointer Zfat-deficiency leads to reduction in the number of the peripheral T cells. Black-Right-Pointing-Pointer Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Decreased expression of IL-7R{alpha}, IL-2R{alpha} and IL-2 in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7R{alpha} and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2R{alpha} expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

Doi, Keiko [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan) [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute of Life Sciences for the Next Generation of Women Scientists, Fukuoka University, Fukuoka (Japan); Fujimoto, Takahiro [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan) [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Okamura, Tadashi [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan)] [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan); Ogawa, Masahiro [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan)] [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Tanaka, Yoko [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan)] [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Mototani, Yasumasa; Goto, Motohito [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan)] [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan); Ota, Takeharu; Matsuzaki, Hiroshi [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan)] [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Kuroki, Masahide [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan)] [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Tsunoda, Toshiyuki [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan) [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Sasazuki, Takehiko [Institute for Advanced Study, Kyushu University, Fukuoka (Japan)] [Institute for Advanced Study, Kyushu University, Fukuoka (Japan); Shirasawa, Senji, E-mail: [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan) [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan)



MicroRNA-128-3p is a novel oncomiR targeting PHF6 in T-cell acute lymphoblastic leukemia  

PubMed Central

T-cell acute lymphoblastic leukemia arises from the leukemic transformation of developing thymocytes and results from cooperative genetic lesions. Inactivation of the PHF6 gene is frequently observed in T-cell acute lymphoblastic leukemia, suggesting an important tumor suppressive role for PHF6 in the pathobiology of this leukemia. Although the precise function of PHF6 is still unknown, this gene is most likely involved in chromatin regulation, a strongly emerging theme in T-cell acute lymphoblastic leukemia. In this context, our previous description of a cooperative microRNA regulatory network controlling several well-known T-cell acute lymphoblastic leukemia tumor suppressor genes, including PHF6, is of great importance. Given the high frequency of PHF6 lesions in T-cell acute lymphoblastic leukemia and the integration of PHF6 in this microRNA regulatory network, we aimed to identify novel oncogenic microRNAs in T-cell acute lymphoblastic leukemia which suppress PHF6. To this end, we performed an unbiased PHF6 3?UTR-microRNA library screen and combined the results with microRNA profiling data of samples from patients with T-cell acute lymphoblastic leukemia and normal thymocyte subsets. We selected miR-128-3p as a candidate PHF6-targeting, oncogenic microRNA and demonstrated regulation of PHF6 expression upon modulation of this microRNA in T-cell acute lymphoblastic leukemia cell lines. In vivo evidence of an oncogenic role of this microRNA in T-cell acute lymphoblastic leukemia was obtained through accelerated leukemia onset in a NOTCH1-induced T-cell acute lymphoblastic leukemia mouse model upon miR-128-3p over-expression. We conclude that miR-128-3p is a strong novel candidate oncogenic microRNA in T-cell acute lymphoblastic leukemia which targets the PHF6 tumor suppressor gene. PMID:24895337

Mets, Evelien; Van Peer, Gert; Van der Meulen, Joni; Boice, Michael; Taghon, Tom; Goossens, Steven; Mestdagh, Pieter; Benoit, Yves; De Moerloose, Barbara; Van Roy, Nadine; Poppe, Bruce; Vandesompele, Jo; Wendel, Hans-Guido; Van Vlierberghe, Pieter; Speleman, Frank; Rondou, Pieter



Attenuation of Peripheral Regulatory T-Cell Suppression of Skin-Homing CD8+T Cells in Atopic Dermatitis  

PubMed Central

Purpose Cutaneous lymphocyte-associated antigen (CLA)-expressing CD8+T cells have been known to play an important role in the pathogenesis of atopic dermatitis (AD). However, the mechanisms underlying the loss of self-tolerance remain unclear. Regulatory T cells (Tregs) play a key role in the development of homeostasis in the immune system. We, therefore, hypothesized that a reduced ability of Tregs to inhibit autologous CD8+CLA+T cells might be underlying mechanism in AD. Materials and Methods CD8+CLA+T cells and Tregs were obtained from the peripheral blood of AD patients and control volunteers. The frequencies of CD8+CLA+T cells were evaluated. The proliferative responses of CD8+CLA+T cells were assessed by flow cytometry, and the levels of transforming growth factor-?1 (TGF-?1) and interleukin-10 (IL-10) in culture supernatants were detected by enzyme-linked immunosorbent assay. Results Our results revealed higher frequency and increased expression of perforin and granzyme-B in peripheral CD8+CLA+T cells in AD, and lower inhibitory ability of Tregs on proliferation of CD8+CLA+T cells in AD. Meanwhile, the levels of TGF-?1 produced by Tregs were significantly lower in AD, and anti-TGF-?1 abolished such suppression. Conclusion The attenuated inhibitory ability of Tregs on hyper-activated autologous CD8+CLA+T cells, mediated by TGF-?1, plays an important role in the pathogenesis of AD. PMID:25510765

Zhang, Bao-Xiang; Lyu, Jun-Cheng; Liu, Hai-Bo; Feng, Dian-Qin; Zhang, Dian-Cai; Bi, Xing-Jie; Duan, Zhi-Wu



TGF-? Signalling Is Required for CD4+ T Cell Homeostasis But Dispensable for Regulatory T Cell Function  

PubMed Central

TGF-? is widely held to be critical for the maintenance and function of regulatory T (Treg) cells and thus peripheral tolerance. This is highlighted by constitutive ablation of TGF-? receptor (TR) during thymic development in mice, which leads to a lethal autoimmune syndrome. Here we describe that TGF-?–driven peripheral tolerance is not regulated by TGF-? signalling on mature CD4+ T cells. Inducible TR2 ablation specifically on CD4+ T cells did not result in a lethal autoinflammation. Transfer of these TR2-deficient CD4+ T cells to lymphopenic recipients resulted in colitis, but not overt autoimmunity. In contrast, thymic ablation of TR2 in combination with lymphopenia led to lethal multi-organ inflammation. Interestingly, deletion of TR2 on mature CD4+ T cells does not result in the collapse of the Treg cell population as observed in constitutive models. Instead, a pronounced enlargement of both regulatory and effector memory T cell pools was observed. This expansion is cell-intrinsic and seems to be caused by increased T cell receptor sensitivity independently of common gamma chain-dependent cytokine signals. The expression of Foxp3 and other regulatory T cells markers was not dependent on TGF-? signalling and the TR2–deficient Treg cells retained their suppressive function both in vitro and in vivo. In summary, absence of TGF-? signalling on mature CD4+ T cells is not responsible for breakdown of peripheral tolerance, but rather controls homeostasis of mature T cells in adult mice. PMID:24115907

?ledzi?ska, Anna; Hemmers, Saskia; Mair, Florian; Gorka, Oliver; Ruland, Jürgen; Fairbairn, Lynsey; Nissler, Anja; Müller, Werner; Waisman, Ari



Molecular mimicry in T cell-mediated autoimmunity: Viral peptides activate human T cell clones specific for myelin basic protein  

Microsoft Academic Search

Structural similarity between viral T cell epitopes and self-peptides could lead to the induction of an autoaggressive T cell response. Based on the structural requirements for both MHC class 11 binding and TCR recognition of an immunodominant myelin basic protein (MBP) peptide, criteria for a data base search were developed in which the degeneracy of amino acid side chains required

Kai W Wucherpfennig; Jack L Strominger



Evidence for extrathymic T cell maturation after thymectomy in infancy  

PubMed Central

Our previous study showed that children who had been partially or completely thymectomized during heart surgery as infants had lower proportions and numbers of total lymphocytes and reduced proportions of T cells (CD3+), helper T cells (CD4+) and naive T cells (CD3+ CD4+ CD45RA+), but normal proportion of cytotoxic T cells (CD8+). In this study T lymphocytes from a selected group of eight of these children and age- and gender-matched controls were characterized further using flow cytometry to determine phenotypes of T cells and T cell subsets related to T cell regulation and phenotypes suggestive of extrathymic maturation. Immune function was assessed by measuring autoantibodies and antibodies against vaccines. The study group had significantly lower numbers of all the main subsets of T lymphocytes and the composition was different. Thus, the proportions of lymphocytes with the following phenotypes: CD3+, CD2+, CD7+, CD4+, CD62L+, CD4+ CD62L+ and CD4+ CD69? were significantly reduced in the study group compared with the control group, but significantly higher proportions were seen of lymphocytes expressing CD8?+ CD8?? and TCR??+ CD8?+ CD8??. The absolute number and proportion of CD4+ CD25+ cells were reduced but the proportions of the subgroup of naive regulatory T cells (CD4+ CD25+ CD62L+) and non-activated regulatory T cells (CD4+ CD25+ CD69?) were not reduced in the thymectomized children. We conclude that the phenotypic characteristics of T lymphocytes of children who have lost their thymus in infancy are indicative of extrathymic maturation. T regulatory cells appear to be less affected than other subsets by the general reduction in T cell numbers. PMID:16907907

Torfadottir, H; Freysdottir, J; Skaftadottir, I; Haraldsson, A; Sigfusson, G; Ogmundsdottir, H M



T-cell receptor repertoire of circulating gamma delta T-cells in Takayasu's arteritis.  


We studied T-cell receptor (TCR) repertoire of circulating gamma delta (gammadelta) T-cells in 20 patients with Takayasu's arteritis (TA), 20 healthy controls (HC), 7 follow up TA patients, and 10 patients with rheumatoid arthritis (RA) and 5 Wegener's granulomatosis (WG) patients as disease controls. Patients with TA (8.1 +/- 5.1%) compared to HC (3.7 +/- 2.1%, P = 0.014), RA (4.8 +/- 0.6%, P = 0.032), and WG (4.2 +/- 0.8%, P = 0.030) as well as active TA compared to inactive TA (13.9 +/- 4.1% vs. 4.9 +/- 1.5%; P < 0.001) had higher number of gammadelta T-cells. The numbers of Vdelta1+ cells were significantly higher in patients with TA (40.0 +/- 20.8%) than HC (13.1 +/- 8.0%; P = 0.001), RA (19.5 +/- 1.8%, P = 0.004), and WG (17.0 +/- 3.9%, P = 0.007). The numbers of gammadelta T-cells normalized in all the 7 patients after 180 days of follow up (13.9 +/- 4.1% vs. 6.9 +/- 2.5%; P = 0.001). We also observed higher number of activated and IFN-gamma producing gammadelta T-cells in active TA. Our data show that gammadelta T-cells particularly those bearing Vdelta1 TCR may have an important role in the immunopathogenesis of TA. PMID:16307908

Chauhan, Sunil Kumar; Tripathy, Naresh Kumar; Sinha, Nakul; Nityanand, Soniya



Fli-1 regulates the DN2 to DN3 thymocyte transition and promotes ?? T-cell commitment by enhancing TCR signal strength.  


Friend leukemia integration 1 (Fli-1) is a member of the Ets transcription factor family and is expressed during T-cell development; however, the role Fli-1 plays in early T-cell differentiation has not been elucidated. In this report, we demonstrate that in mouse, Fli-1 overexpression retards the CD4(-) CD8(-) double-negative (DN) to CD4(+) CD8(+) double-positive (DP) transition by deregulating normal DN thymocyte development. Specifically, Fli-1 expression moderates the DN2 and DN3 developmental transitions. We further show that Fli-1 overexpression partially mimics strong TCR signals in developing DN thymocytes and thereby enhances ?? T-cell development. Conversely, Fli-1 knockdown by small hairpin RNA reverses the lineage bias from ?? T cells and directs DN cells to the ?? lineage by attenuating TCR signaling. Therefore, Fli-1 plays a critical role in both the DN2 to DN3 transition and ??/?? lineage commitment. PMID:24935715

Smeets, Monique F M A; Wiest, David L; Izon, David J



Selective CD4+ T-cell depletion does not prevent graft-versus-host disease.  


Donor-derived CD4+ T cells may play a role in the development of graft-versus-host disease (GVHD) and graft-versus-leukemia reaction after allogeneic bone marrow transplantation (BMT). Therefore, we evaluated the effect of CD4+ T-cell depletion on GVHD and graft-versus-leukemia reaction after HLA-matched BMT. CD4 depletion was performed using anti-CD4 monoclonal antibodies and immunomagnetic beads, initially in small-scale experiments on bone marrow and granulocyte colony-stimulating factor-mobilized peripheral blood apheresis products. The result was elimination of the CD4+ T cells from both sources (0% and 2+/-1.4% CD4+ cells, respectively). Subsequently, we used this technique for large-scale negative selection of CD4+ T cells from bone marrow grafts of four consenting leukemic patients in relapse (ALL-3, ANLL-1) (M-3, F-1). The large-scale CD4+ T-cell depletion resulted in >98% (n=4) elimination of CD4+ cells. The resulting population included 17.7+/-4.6% CD3+ T cells, 8.9+/-2.5% CD8+ T cells, 0.1+/-0.1% CD16+ natural killer cells, and 2.3+/-3.2% CD34+ hematopoietic progenitor cells. Patients were transplanted with 2.84+/-1.31 x 10(8) viable cells/kg. They received cyclosporine starting on day -1 as GVHD prophylaxis. Engraftment was fast with a white blood cell count of >1 x 10(9)/L on day 13.2+/-0.5, an absolute neutrophil count of >0.5 x 10(9)/L on day 13.8+/-0.5, and a platelet count of >25 x 10(9)/L on day 26.5+/-6.8. Immunological reconstitution was normal, and peripheral blood phenotyping 3 weeks after BMT disclosed 49.0+/-5.0% CD3, 14.3+/-12.4% CD4, and 59.5+/-7.8% CD8 T cells in addition to 17.0+/-3.0% CD16+ and 9.0+/-3.0% CD56 natural killer cells. Three out of four patients developed very early grade IV GVHD beginning on day 12 (10-13) and died 2-4 months after BMT. One patient is alive and well with a follow-up of 36 months. We conclude that selective CD4 T-cell depletion does not prevent GVHD. PMID:9679838

Nagler, A; Condiotti, R; Nabet, C; Naparstek, E; Or, R; Samuel, S; Slavin, S



Force Generation upon T Cell Receptor Engagement  

PubMed Central

T cells are major players of adaptive immune response in mammals. Recognition of an antigenic peptide in association with the major histocompatibility complex at the surface of an antigen presenting cell (APC) is a specific and sensitive process whose mechanism is not fully understood. The potential contribution of mechanical forces in the T cell activation process is increasingly debated, although these forces are scarcely defined and hold only limited experimental evidence. In this work, we have implemented a biomembrane force probe (BFP) setup and a model APC to explore the nature and the characteristics of the mechanical forces potentially generated upon engagement of the T cell receptor (TCR) and/or lymphocyte function-associated antigen-1 (LFA-1). We show that upon contact with a model APC coated with antibodies towards TCR-CD3, after a short latency, the T cell developed a timed sequence of pushing and pulling forces against its target. These processes were defined by their initial constant growth velocity and loading rate (force increase per unit of time). LFA-1 engagement together with TCR-CD3 reduced the growing speed during the pushing phase without triggering the same mechanical behavior when engaged alone. Intracellular Ca2+ concentration ([Ca2+]i) was monitored simultaneously to verify the cell commitment in the activation process. [Ca2+]i increased a few tens of seconds after the beginning of the pushing phase although no strong correlation appeared between the two events. The pushing phase was driven by actin polymerization. Tuning the BFP mechanical properties, we could show that the loading rate during the pulling phase increased with the target stiffness. This indicated that a mechanosensing mechanism is implemented in the early steps of the activation process. We provide here the first quantified description of force generation sequence upon local bidimensional engagement of TCR-CD3 and discuss its potential role in a T cell mechanically-regulated activation process. PMID:21572959

Husson, Julien; Chemin, Karine; Bohineust, Armelle; Hivroz, Claire; Henry, Nelly



PD-1 blockade by CT-011, anti-PD-1 antibody, enhances ex vivo T-cell responses to autologous dendritic cell/myeloma fusion vaccine.  


We have developed a cancer vaccine in which autologous tumor is fused with dendritic cells (DCs) resulting in the presentation of tumor antigens in the context of DC-mediated costimulation. In clinical trials, immunologic responses have been observed, however responses may be muted by inhibitory pathways. The PD1/PDL1 pathway is an important element contributing to tumor-mediated immune suppression. In this study, we demonstrate that myeloma cells and DC/tumor fusions strongly express PD-L1. Compared with a control population of normal volunteers, increased PD-1 expression was observed on T cells isolated from patients with myeloma. It is interesting to note that after autologous transplantation, T-cell expression of PD-1 returned to levels seen in normal controls. We examined the effect of PD-1 blockade on T-cell response to DC/tumor fusions ex vivo. Presence of CT-011, an anti-PD1 antibody, promoted the vaccine-induced T-cell polarization towards an activated phenotype expressing Th1 compared with Th2 cytokines. A concomitant decrease in regulatory T cells and enhanced killing in a cytotoxicity assay was observed. In summary, we demonstrate that PD-1 expression is increased in T cells of patients with active myeloma, and that CT-011 enhances activated T-cell responses after DC/tumor fusion stimulation. PMID:21577144

Rosenblatt, Jacalyn; Glotzbecker, Brett; Mills, Heidi; Vasir, Baldev; Tzachanis, Dimitrios; Levine, James D; Joyce, Robin M; Wellenstein, Kerry; Keefe, Whitney; Schickler, Michael; Rotem-Yehudar, Rinat; Kufe, Donald; Avigan, David



Oligoclonality of human intestinal intraepithelial T cells  

PubMed Central

T cells bearing the T cell receptor alpha/beta (TCR-alpha/beta) are the predominant lymphocyte population in the human intestinal epithelium. To examine if normal intestinal intraepithelial lymphocytes (IEL) have a TCR repertoire distinct from the TCR-alpha/beta repertoire in peripheral blood lymphocytes (PBL), comparative analysis of relative V beta gene usage in IEL and PBL was performed by quantitative polymerase chain reaction. In each of the six individuals examined, one to three V beta families made up more than 40% of the total V beta transcripts detected in the IEL, whereas there was a more even distribution of V beta gene usage in the paired PBL. The predominant V beta families, especially V beta 1, V beta 2, V beta 3, and V beta 6, were frequently shared among IEL of different individuals. PCR cloning and sequence analysis of the predominant V beta 6 family in two individuals revealed an identical V-D-J-C sequence in 13 of 21 clones obtained from one donor, and a different repeated sequence in 18 of 27 clones examined in the second donor. These data suggest that the V beta skewing in IEL is due to an oligoclonal T cell expansion and may reflect the response of the intestinal mucosal immune system to a restricted set of as yet undefined antigens present in the gut. PMID:1730926



Visual Inspection Versus Quantitative Flow Cytometry to Detect Aberrant CD2 Expression in Malignant T Cells  

PubMed Central

Background Abnormal levels of T cell antigen expression occur in T cell neoplasia. We examined CD2 expression in malignant and normal T cells to determine if the level of CD2 expression differed significantly and if quantitation assisted in detecting this difference. Method Flow cytometric immunophenotypic (FCI) evaluation was performed on specimens from 36 patients with mature T cell neoplasia. Abnormal T cells were identified based upon abnormal FCI and morphology. Levels of CD2 expression were quantitated using 1:1 PE conjugates of anti-CD2 and QuantiBRITE bead standards to calculate the antibodies bound per cell (ABC). The efficacy of ABC measurement verses simple examination of dots plots was compared. Results Abnormal levels of CD2 expression were frequently observed in mature T cell malignancies. The CD2 ABC values were highly sensitive in detecting differences between malignant and normal T cells (p=0.0028). In most cases (24/32 specimens, 75%) CD2 ABCs differed by > 20%. CD2 ABCs had high variability in normal T cells. Conclusions CD2 expression by malignant T cells differed significantly from that of normal T-cells by CD2 ABC quantitation. The high variability in normal T cell CD2 ABCs limited the determination of normal reference ranges, and thus its utility in the diagnosis of T cell neoplasia. However, examination of CD2 can help in detection of tumor cells when residual normal T cells are present for comparison. Moreover, the increased sensitivity of CD2 quantitation is valuable in confirming FCI cases where abnormalities in CD2 expression are difficult to appreciate by visual inspection alone. PMID:20020522

Arun, Indu; Wulu, Jacqueline A.; Janik, John E.; Jasper, Gregory A.; Yuan, Constance M.; Venzon, David; Stetler-Stevenson, Maryalice



Chapter 2. Normal Plant Appearance and Development  

Technology Transfer Automated Retrieval System (TEKTRAN)

Most often, agronomists evaluate crop health by examining aboveground plant growth and canopy appearance. It is important to know when stresses occur relative to critical events in the development of the crop. This enables an agronomist to more effectively and efficiently employ management practices...


Movie of normal C. elegans development  

NSDL National Science Digital Library

C. elegans develops from a single cell, the fertilized egg, to a 558-celled worm in about 14 hours. The worm that crawls out of its eggshell has a functioning feeding apparatus, gut, nervous system and muscles. This movie shows that in time lapse.

PhD Bob Goldstein (UNC Chapel Hill Biology Dept,)



Shaping the repertoire of tumor-infiltrating effector and regulatory T cells.  


Many tumors express antigens that can be specifically or selectively recognized by T lymphocytes, suggesting that T-cell-mediated immunity may be harnessed for the immunotherapy of cancer. However, since tumors originate from normal cells and evolve within the context of self-tissues, the immune mechanisms that prevent the autoimmune attack of normal tissues function in parallel to restrict anti-tumor immunity. In particular, the purging of autoreactive T cells and the development of immune-suppressive regulatory T cells (Tregs) are thought to be major barriers impeding anti-tumor immune responses. Here, we discuss current understanding regarding the antigens recognized by tumor-infiltrating T-cell populations, the mechanisms that shape the repertoire of these cells, and the role of the transcription factor autoimmune regulator (Aire) in these processes. Further elucidation of these principles is likely to be critical for optimizing emerging cancer immunotherapies, and for the rational design of novel therapies exhibiting robust anti-tumor activity with limited toxicity. PMID:24712470

Savage, Peter A; Leventhal, Daniel S; Malchow, Sven



BOOK REVIEW The Kidney: From Normal Development to Congenital Disease  

E-print Network

BOOK REVIEW The Kidney: From Normal Development to Congenital Disease Editors: Peter D. Vize. The Kidney: From Normal Development to Congenital Disease, edited by Peter Vize, Adrian Woolf, and Johnathan for improvement down the road. The chapters dealing with congenital disorders are sparse to a fault

Vize, Peter D.


Nfatc2 and Tob1 Have Non-Overlapping Function in T Cell Negative Regulation and Tumorigenesis  

PubMed Central

Nfatc2 and Tob1 are intrinsic negative regulators of T cell activation. Nfatc2-deficient and Tob1-deficient T cells show reduced thresholds of activation; however, whether these factors have independent or overlapping roles in negative regulation of T cell responses has not been previously examined. Here, we show that Nfatc2 knockout (KO) but not Tob1 KO mice have age-associated accumulation of persistently activated T cells in vivo and expansion of the CD44+ memory cell compartment and age-associated lymphocytic infiltrates in visceral organs, without significant changes in numbers of CD4+CD25+Foxp3+ regulatory T cells (Treg). In vitro, CD4+CD25? “conventional” T cells (Tconvs) from both KO strains showed greater proliferation than wild type (WT) Tconvs. However, while Tregs from Nfatc2 KO mice retained normal suppressive function, Tregs from Tob1 KOs had enhanced suppressive activity. Nfatc2 KO Tconvs expanded somewhat more rapidly than WT Tconvs under conditions of homeostatic proliferation, but their accelerated growth capacity was negated, at least acutely, in a lymphoreplete environment. Finally, Nfatc2 KO mice developed a previously uncharacterized increase in B-cell malignancies, which was not accelerated by the absence of Tob1. The data thus support the prevailing hypothesis that Nfatc2 and Tob1 are non-redundant regulators of lymphocyte homeostasis. PMID:24945807

May, Sarah L.; Zhou, Qing; Lewellen, Mitzi; Carter, Cristan M.; Coffey, David; Highfill, Steven L.; Bucher, Christoph M.; Matise, Ilze; Morse, Herbert C.; O’Sullivan, M. Gerard; Schutten, Melissa; Johnson, Charles; Bellgrau, Donald; Blazar, Bruce R.; Modiano, Jaime F.



In healthy primates, circulating autoreactive T cells mediate autoimmune disease.  

PubMed Central

A T cell response against myelin basic protein (MBP) is thought to contribute to the central nervous system (CNS) inflammation that occurs in the human demyelinating disease multiple sclerosis. To test whether MBP-reactive T cells that are normally retrieved from the circulation are capable of inducing CNS disease, MBP-reactive T cell clones were isolated from the peripheral blood of healthy, unimmunized Callithrix jacchus (C. jacchus) marmosets. This primate species is characterized by a natural chimerism of bone marrow elements between siblings that should make possible adoptive transfer of MBP-reactive T cells. We report that MBP-reactive T cell clones efficiently and reproducibly transfer CNS inflammatory disease between members of C. jacchus chimeric sets. The demyelination that is characteristic of experimental allergic encephalomyelitis induced in C. jacchus by immunization against human white matter did not occur after adoptive transfer of the MBP-reactive clones. It was noteworthy that encephalitogenic T cell clones were diverse in terms of their recognition of different epitopes of MBP, distinguishing the response in C. jacchus from that in some inbred rodents in which restricted recognition of MBP occurs. These findings are the first direct evidence that natural populations of circulating T cells directed against a CNS antigen can mediate an inflammatory autoimmune disease. Images PMID:7521889

Genain, C P; Lee-Parritz, D; Nguyen, M H; Massacesi, L; Joshi, N; Ferrante, R; Hoffman, K; Moseley, M; Letvin, N L; Hauser, S L



Mesothelin-specific Chimeric Antigen Receptor mRNA-Engineered T cells Induce Anti-Tumor Activity in Solid Malignancies  

PubMed Central

Off-target toxicity due to the expression of target antigens in normal tissue represents a major obstacle to the use of chimeric antigen receptor (CAR)-engineered T cells for treatment of solid malignancies. To circumvent this issue, we established a clinical platform for engineering T cells with transient CAR expression by using in vitro transcribed mRNA encoding a CAR that includes both the CD3-? and 4-1BB co-stimulatory domains. We present two case reports from ongoing trials indicating that adoptive transfer of mRNA CAR T cells that target mesothelin (CARTmeso cells) is feasible and safe without overt evidence of off-tumor on-target toxicity against normal tissues. CARTmeso cells persisted transiently within the peripheral blood after intravenous administration and migrated to primary and metastatic tumor sites. Clinical and laboratory evidence of antitumor activity was demonstrated in both patients and the CARTmeso cells elicited an antitumor immune response revealed by the development of novel anti-self antibodies. These data demonstrate the potential of utilizing mRNA engineered T cells to evaluate, in a controlled manner, potential off-tumor on-target toxicities and show that short-lived CAR T cells can induce epitope-spreading and mediate antitumor activity in patients with advanced cancer. Thus, these findings support the development of mRNA CAR-based strategies for carcinoma and other solid tumors. PMID:24579088

Beatty, Gregory L.; Haas, Andrew R.; Maus, Marcela V.; Torigian, Drew A.; Soulen, Michael C.; Plesa, Gabriela; Chew, Anne; Zhao, Yangbing; Levine, Bruce L.; Albelda, Steven M.; Kalos, Michael; June, Carl H.



Mesothelin-specific chimeric antigen receptor mRNA-engineered T cells induce anti-tumor activity in solid malignancies.  


Off-target toxicity due to the expression of target antigens in normal tissue represents a major obstacle to the use of chimeric antigen receptor (CAR)-engineered T cells for treatment of solid malignancies. To circumvent this issue, we established a clinical platform for engineering T cells with transient CAR expression by using in vitro transcribed mRNA encoding a CAR that includes both the CD3-? and 4-1BB co-stimulatory domains. We present two case reports from ongoing trials indicating that adoptive transfer of mRNA CAR T cells that target mesothelin (CARTmeso cells) is feasible and safe without overt evidence of off-tumor on-target toxicity against normal tissues. CARTmeso cells persisted transiently within the peripheral blood after intravenous administration and migrated to primary and metastatic tumor sites. Clinical and laboratory evidence of antitumor activity was demonstrated in both patients and the CARTmeso cells elicited an antitumor immune response revealed by the development of novel anti-self antibodies. These data demonstrate the potential of utilizing mRNA engineered T cells to evaluate, in a controlled manner, potential off-tumor on-target toxicities and show that short-lived CAR T cells can induce epitope-spreading and mediate antitumor activity in patients with advanced cancer. Thus, these findings support the development of mRNA CAR-based strategies for carcinoma and other solid tumors. PMID:24579088

Beatty, Gregory L; Haas, Andrew R; Maus, Marcela V; Torigian, Drew A; Soulen, Michael C; Plesa, Gabriela; Chew, Anne; Zhao, Yangbing; Levine, Bruce L; Albelda, Steven M; Kalos, Michael; June, Carl H



Structural and biophysical determinants of ?? T-cell antigen recognition  

PubMed Central

The molecular rules that govern MHC restriction, and allow T-cells to differentiate between peptides derived from healthy cells and those from diseased cells, remain poorly understood. Here we provide an overview of the structural constraints that enable the T-cell receptor (TCR) to discriminate between self and non-self peptides, and summarize studies that have attempted to correlate the biophysical parameters of TCR/peptide–major histocompatibility complex (pMHC) binding with T-cell activation. We further review how the antigenic origin of peptide epitopes affects TCR binding parameters and the ‘quality’ of a T-cell response. Understanding the principles that govern pMHC recognition by T-cells will unlock pathways to the rational development of immunotherapeutic approaches for the treatment of infectious disease, cancer and autoimmunity. PMID:22044041

Bridgeman, John S; Sewell, Andrew K; Miles, John J; Price, David A; Cole, David K



Genetic, hormonal and behavioural influence on spontaneously developing arthritis in normal mice.  

PubMed Central

DBA/1 male mice develop arthritis spontaneously at the age of 4 months. The affected joints show cell-rich pannus formation without T cell infiltration and only limited MHC class II expression. Specific pathogen-free DBA/1 mice from different sources developed the same disease. Analyses of inbred mouse strains with various genetic backgrounds and F1 hybrids revealed that the disease is genetically dependent of DBA/1 recessive genes. However, F1 hybrids between DBA/1 and BXSB spontaneously developed arthritis with earlier onset than DBA/1 mice, suggesting that the BXSB autoimmune gene background had both permissive and contributing effects on the development of arthritis. The complete male preponderance for disease susceptibility was investigated by castration and testosterone treatment of DBA/1 males. No arthritis developed after castration and disease susceptibility was restored by testosterone treatment. Arthritis developed only where more than two males were kept in cages, suggesting an influence by aggressive behaviour. Thus, the spontaneous development of arthritis is dependent on hormonal and behavioural mediated effects and differs from experimental models for rheumatoid arthritis such as type II collagen-induced arthritis and pristane-induced arthritis. We conclude that the spontaneously developing arthritis in the normal DBA/1 strain may be more useful as a disease model for osteoarthritis than for rheumatoid arthritis. Images Fig. 1 Fig. 3 PMID:1606732

Holmdahl, R; Jansson, L; Andersson, M; Jonsson, R



Virus persistence in acutely infected immunocompetent mice by exhaustion of antiviral cytotoxic effector T cells  

Microsoft Academic Search

VIRUSES that are non- or poorly cytopathic have developed various strategies to avoid elimination by the immune system and to persist in the host1-3. Acute infection of adult mice with the noncytopathic lymphocytic choriomeningitis virus (LCMV) normally induces a protective cytotoxic T-cell response that also causes immunopathology4-7. But some LCMV strains (such as DOCILE8 (LCMV-D) or Cl-13 Armstrong (Cl-13) 9)

Demetrius Moskophidis; Franziska Lechner; Hanspeter Pircher; Rolf M. Zinkernagel



Cytotoxic T Cells Mediate Pathology and Metastasis in Cutaneous Leishmaniasis  

PubMed Central

Disease progression in response to infection can be strongly influenced by both pathogen burden and infection-induced immunopathology. While current therapeutics focus on augmenting protective immune responses, identifying therapeutics that reduce infection-induced immunopathology are clearly warranted. Despite the apparent protective role for murine CD8+ T cells following infection with the intracellular parasite Leishmania, CD8+ T cells have been paradoxically linked to immunopathological responses in human cutaneous leishmaniasis. Transcriptome analysis of lesions from Leishmania braziliensis patients revealed that genes associated with the cytolytic pathway are highly expressed and CD8+ T cells from lesions exhibited a cytolytic phenotype. To determine if CD8+ T cells play a causal role in disease, we turned to a murine model. These studies revealed that disease progression and metastasis in L. braziliensis infected mice was independent of parasite burden and was instead directly associated with the presence of CD8+ T cells. In mice with severe pathology, we visualized CD8+ T cell degranulation and lysis of L. braziliensis infected cells. Finally, in contrast to wild-type CD8+ T cells, perforin-deficient cells failed to induce disease. Thus, we show for the first time that cytolytic CD8+ T cells mediate immunopathology and drive the development of metastatic lesions in cutaneous leishmaniasis. PMID:23874205

Novais, Fernanda O.; Carvalho, Lucas P.; Graff, Joel W.; Beiting, Daniel P.; Ruthel, Gordon; Roos, David S.; Betts, Michael R.; Goldschmidt, Michael H.; Wilson, Mary E.; de Oliveira, Camila I.; Scott, Phillip



Adolescent brain development in normality and psychopathology  

PubMed Central

Since this journal’s inception, the field of adolescent brain development has flourished, as researchers have investigated the underpinnings of adolescent risk-taking behaviors. Explanations based on translational models initially attributed such behaviors to executive control deficiencies and poor frontal lobe function. This conclusion was bolstered by evidence that the prefrontal cortex and its interconnections are among the last brain regions to structurally and functionally mature. As substantial heterogeneity of prefrontal function was revealed, applications of neuroeconomic theory to adolescent development led to dual systems models of behavior. Current epidemiological trends, behavioral observations, and functional magnetic resonance imaging based brain activity patterns suggest a quadratic increase in limbically mediated incentive motivation from childhood to adolescence and a decline thereafter. This elevation occurs in the context of immature prefrontal function, so motivational strivings may be difficult to regulate. Theoretical models explain this patterning through brain-based accounts of subcortical–cortical integration, puberty-based models of adolescent sensation seeking, and neurochemical dynamics. Empirically sound tests of these mechanisms, as well as investigations of biology–context interactions, represent the field’s most challenging future goals, so that applications to psychopathology can be refined and so that developmental cascades that incorporate neurobiological variables can be modeled. PMID:24342843




Loss of T cell precursors after spaceflight and exposure to vector-averaged gravity  

NASA Technical Reports Server (NTRS)

Using fetal thymus organ culture (FTOC), we examined the effects of spaceflight and vector-averaged gravity on T cell development. Under both conditions, the development of T cells was significantly attenuated. Exposure to spaceflight for 16 days resulted in a loss of precursors for CD4+, CD8+, and CD4+CD8+ T cells in a rat/mouse xenogeneic co-culture. A significant decrease in the same precursor cells, as well as a decrease in CD4-CD8- T cell precursors, was also observed in a murine C57BL/6 FTOC after rotation in a clinostat to produce a vector-averaged microgravity-like environment. The block in T cell development appeared to occur between the pre-T cell and CD4+CD8+ T cell stage. These data indicate that gravity plays a decisive role in the development of T cells.

Woods, Chris C.; Banks, Krista E.; Gruener, Raphael; DeLuca, Dominick



Impact of sepsis on CD4 T cell immunity.  


Sepsis remains the primary cause of death from infection in hospital patients, despite improvements in antibiotics and intensive-care practices. Patients who survive severe sepsis can display suppressed immune function, often manifested as an increased susceptibility to (and mortality from) nosocomial infections. Not only is there a significant reduction in the number of various immune cell populations during sepsis, but there is also decreased function in the remaining lymphocytes. Within the immune system, CD4 T cells are important players in the proper development of numerous cellular and humoral immune responses. Despite sufficient clinical evidence of CD4 T cell loss in septic patients of all ages, the impact of sepsis on CD4 T cell responses is not well understood. Recent findings suggest that CD4 T cell impairment is a multipronged problem that results from initial sepsis-induced cell loss. However, the subsequent lymphopenia-induced numerical recovery of the CD4 T cell compartment leads to intrinsic alterations in phenotype and effector function, reduced repertoire diversity, changes in the composition of naive antigen-specific CD4 T cell pools, and changes in the representation of different CD4 T cell subpopulations (e.g., increases in Treg frequency). This review focuses on sepsis-induced alterations within the CD4 T cell compartment that influence the ability of the immune system to control secondary heterologous infections. The understanding of how sepsis affects CD4 T cells through their numerical loss and recovery, as well as function, is important in the development of future treatments designed to restore CD4 T cells to their presepsis state. PMID:24791959

Cabrera-Perez, Javier; Condotta, Stephanie A; Badovinac, Vladimir P; Griffith, Thomas S



T cell antigen receptor V gene usage. Increases in V beta 8+ T cells in Crohn's disease.  

PubMed Central

Crohn's disease represents part of a spectrum of inflammatory bowel diseases characterized by immune regulatory defects and genetic predisposition. T cell antigen receptor V gene usage by T lymphocytes was investigated using four MAbs specific for various V gene products. One MAb (Ti3a), reactive with V beta 8 gene products, detected increased numbers of T cells in a subset of Crohn's disease patients as compared with normal controls and ulcerative colitis patients. In family studies there was no apparent inherited predisposition to the use of V beta 8 genes, and there was no association between a restriction fragment length polymorphism of the V beta 8.1 gene and Crohn's disease. The V beta 8+ T cells were concentrated in the mesenteric lymph nodes draining the inflammatory lesions and belonged to both the CD4+ and CD8+ T cell subsets. In contrast, lamina propria and intraepithelial T cells were not enriched in V beta 8+ T cells, suggesting that these cells were participating in the afferent limb of a gut-associated immune response. The expanded V beta 8+ T cells in Crohn's disease appear to result from an immune response to an as yet unknown antigen. Images PMID:1971828

Posnett, D N; Schmelkin, I; Burton, D A; August, A; McGrath, H; Mayer, L F



Store-operated Ca2+ entry through ORAI1 is critical for T cell mediated autoimmunity and allograft rejection1  

PubMed Central

ORAI1 is the pore forming subunit of the Ca2+ release activated Ca2+ (CRAC) channel, which is responsible for store-operated Ca2+ entry (SOCE) in lymphocytes. A role for ORAI1 in T cell function in vivo has been inferred from in vitro studies of T cells from human immunodeficient patients with mutations in ORAI1 and Orai1?/? mice but a detailed analysis of T cell mediated immune responses in vivo in mice lacking functional ORAI1 has been missing. We therefore generated Orai1 knock-in mice (Orai1KI/KI) expressing a nonfunctional ORAI1-R93W protein. Homozygosity for the equivalent ORAI1-R91W mutation abolishes CRAC channel function in human T cells resulting in severe immunodeficiency. Homozygous Orai1KI/KI mice die neonatally but Orai1KI/KI fetal liver chimeric mice are viable and show normal lymphocyte development. T and B cells from Orai1KI/KI mice display severely impaired SOCE and CRAC channel function resulting in a strongly reduced expression of several key cytokines including IL-2, IL-4, IL-17, IFN-? and TNF-? in CD4+ and CD8+ T cells. Cell mediated immune responses in vivo that depend on TH1, TH2 and TH17 cell function were severely attenuated in ORAI1 deficient mice. Orai1KI/KI mice lacked detectable contact hypersensitivity responses and tolerated skin allografts significantly longer than wildtype mice. In addition, T cells from Orai1KI/KI mice failed to induce colitis in an adoptive transfer model of inflammatory bowel disease. These findings reaffirm the critical role of ORAI1 for T cell function and provide new insights into the in vivo functions of CRAC channels for T cell mediated immunity. PMID:20956344

McCarl, Christie-Ann; Khalil, Sara; Ma, Jian; Oh-hora, Masatsugu; Yamashita, Megumi; Roether, Jens; Kawasaki, Takumi; Jairaman, Amit; Sasaki, Yoshiteru; Prakriya, Murali; Feske, Stefan



MEETING ABSTRACT Open Access HTLV-1 propels thymic human T cell  

E-print Network

MEETING ABSTRACT Open Access HTLV-1 propels thymic human T cell development in "human immune system have previously shown that HTLV-1 (Human T cell Leukemia Virus type 1) is able not only to infect for early T cell development. To further clarify the role of the natural HTLV-1 infection on human T

Paris-Sud XI, Université de


Islet-specific T-cell clones from nonobese diabetic mice express heterogeneous T-cell receptors.  

PubMed Central

Nonobese diabetic (NOD) mice spontaneously develop a T-cell-mediated autoimmune disease that is similar in many respects to insulin-dependent diabetes mellitus in humans. T-cell clones that specifically recognize pancreatic islet cell antigens can be derived from NOD mice, and most of these have been diabetogenic upon transfer to healthy recipients. We report herein the sequences of the T-cell receptor alpha and beta chains from four NOD-derived, islet-specific clones. The sequences are quite heterogeneous--in the junctional regions, specifically--so there seems to be little hope for treating this disease with specific anti-T-cell receptor reagents. This result contrasts with the strikingly restricted junctional region sequences reported for the receptors on clones derived from mice with experimental allergic encephalomyelitis, another T-cell-mediated autoimmune disease. We discuss possible explanations for this difference. PMID:2068098

Candéias, S; Katz, J; Benoist, C; Mathis, D; Haskins, K



Antibodies targeting human OX40 expand effector T cells and block inducible and natural regulatory T cell function  

PubMed Central

Current cancer vaccines induce tumor-specific T cell responses without sustained tumor regression because immunosuppressive elements within the tumor induce exhaustion of effector T cells and infiltration of immune-suppressive regulatory T cells (Tregs). Therefore, much effort has been made to generate agonistic Abs targeting members of the TNFR superfamily, such as OX40, 4- 1BB, and GITR, expressed on effector T cells and Tregs, to reinvigorate T cell effector function and block Treg-suppressive function. In this article, we describe the development of a panel of anti-human OX40 agonistic mouse mAbs that could promote effector CD4+ and CD8+ T cell proliferation, inhibit the induction of CD4+ IL-10 -producing type 1 regulatory T cells, inhibit the expansion of ICOS+IL-10+ Tregs, inhibit TGF-b–induced FOXP3 expression on naive CD4+ T cells, and block natural Treg–suppressive function. We humanized two anti–human OX40 mAb clones, and they retained the potency of their parental clones. These Abs should provide broad opportunities for potential combination therapy to treat a wide realm of cancers and preventative vaccines against infectious diseases. PMID:24014877

Voo, Kui S.; Bover, Laura; Harline, Megan L.; Vien, Long T.; Facchinetti, Valeria; Arima, Kazuhiko; Kwak, Larry W.; Liu, Yong J.



Fish T cells: recent advances through genomics  

USGS Publications Warehouse

This brief review is intended to provide a concise overview of the current literature concerning T cells, advances in identifying distinct T cell functional subsets, and in distinguishing effector cells from memory cells. We compare and contrast a wealth of recent progress made in T cell immunology of teleost, elasmobranch, and agnathan fish, to knowledge derived from mammalian T cell studies. From genome studies, fish clearly have most components associated with T cell function and we can speculate on the presence of putative T cell subsets, and the ability to detect their differentiation to form memory cells. Some recombinant proteins for T cell associated cytokines and antibodies for T cell surface receptors have been generated that will facilitate studying the functional roles of teleost T cells during immune responses. Although there is still a long way to go, major advances have occurred in recent years for investigating T cell responses, thus phenotypic and functional characterization is on the near horizon.

Laing, Kerry J.; Hansen, John D.



ZEB2 drives immature T-cell lymphoblastic leukaemia development via enhanced tumour-initiating potential and IL-7 receptor signalling.  


Early T-cell precursor leukaemia (ETP-ALL) is a high-risk subtype of human leukaemia that is poorly understood at the molecular level. Here we report translocations targeting the zinc finger E-box-binding transcription factor ZEB2 as a recurrent genetic lesion in immature/ETP-ALL. Using a conditional gain-of-function mouse model, we demonstrate that sustained Zeb2 expression initiates T-cell leukaemia. Moreover, Zeb2-driven mouse leukaemia exhibit some features of the human immature/ETP-ALL gene expression signature, as well as an enhanced leukaemia-initiation potential and activated Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signalling through transcriptional activation of IL7R. This study reveals ZEB2 as an oncogene in the biology of immature/ETP-ALL and paves the way towards pre-clinical studies of novel compounds for the treatment of this aggressive subtype of human T-ALL using our Zeb2-driven mouse model. PMID:25565005

Goossens, Steven; Radaelli, Enrico; Blanchet, Odile; Durinck, Kaat; Van der Meulen, Joni; Peirs, Sofie; Taghon, Tom; Tremblay, Cedric S; Costa, Magdaline; Farhang Ghahremani, Morvarid; De Medts, Jelle; Bartunkova, Sonia; Haigh, Katharina; Schwab, Claire; Farla, Natalie; Pieters, Tim; Matthijssens, Filip; Van Roy, Nadine; Best, J Adam; Deswarte, Kim; Bogaert, Pieter; Carmichael, Catherine; Rickard, Adam; Suryani, Santi; Bracken, Lauryn S; Alserihi, Raed; Canté-Barrett, Kirsten; Haenebalcke, Lieven; Clappier, Emmanuelle; Rondou, Pieter; Slowicka, Karolina; Huylebroeck, Danny; Goldrath, Ananda W; Janzen, Viktor; McCormack, Matthew P; Lock, Richard B; Curtis, David J; Harrison, Christine; Berx, Geert; Speleman, Frank; Meijerink, Jules P P; Soulier, Jean; Van Vlierberghe, Pieter; Haigh, Jody J



Developing Visualization Support System for Teaching/Learning Database Normalization  

ERIC Educational Resources Information Center

Purpose: In tertiary institution, some students find it hard to learn database design theory, in particular, database normalization. The purpose of this paper is to develop a visualization tool to give students an interactive hands-on experience in database normalization process. Design/methodology/approach: The model-view-controller architecture…

Folorunso, Olusegun; Akinwale, AdioTaofeek



Geometry and development of relay ramps in normal fault systems  

Microsoft Academic Search

Normal fault zones play a major role in the development of basins and in the migration and trapping of hydrocarbons. The mapping of normal fault systems using seismic data requires careful correlation of faults on adjacent sections, a procedure that often leads to the interpretation of faults as having long, continuous, sinuous traces. Recent work involving detailed mapping of fault

D. C. P. Peacock; D. J. Sanderson



Thymoproteasome shapes immunocompetent repertoire of CD8+ T cells.  


How self-peptides displayed in the thymus contribute to the development of immunocompetent and self-protective T cells is largely unknown. In contrast, the role of thymic self-peptides in eliminating self-reactive T cells and thereby preventing autoimmunity is well established. A type of proteasome, termed thymoproteasome, is specifically expressed by thymic cortical epithelial cells (cTECs) and is required for the generation of optimal cellularity of CD8+ T cells. Here, we show that cTECs displayed thymoproteasome-specific peptide-MHC class I complexes essential for the positive selection of major and diverse repertoire of MHC class I-restricted T cells. CD8+ T cells generated in the absence of thymoproteasomes displayed a markedly altered T cell receptor repertoire that was defective in both allogeneic and antiviral responses. These results demonstrate that thymoproteasome-dependent self-peptide production is required for the development of an immunocompetent repertoire of CD8+ T cells. PMID:20045355

Nitta, Takeshi; Murata, Shigeo; Sasaki, Katsuhiro; Fujii, Hideki; Ripen, Adiratna Mat; Ishimaru, Naozumi; Koyasu, Shigeo; Tanaka, Keiji; Takahama, Yousuke