Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 65
Filter
1.
Annu Rev Immunol ; 36: 549-578, 2018 04 26.
Article in English | MEDLINE | ID: mdl-29677469

ABSTRACT

Signaling through the T cell antigen receptor (TCR) activates a series of tyrosine kinases. Directly associated with the TCR, the SRC family kinase LCK and the SYK family kinase ZAP-70 are essential for all downstream responses to TCR stimulation. In contrast, the TEC family kinase ITK is not an obligate component of the TCR cascade. Instead, ITK functions as a tuning dial, to translate variations in TCR signal strength into differential programs of gene expression. Recent insights into TEC kinase structure have provided a view into the molecular mechanisms that generate different states of kinase activation. In resting lymphocytes, TEC kinases are autoinhibited, and multiple interactions between the regulatory and kinase domains maintain low activity. Following TCR stimulation, newly generated signaling modules compete with the autoinhibited core and shift the conformational ensemble to the fully active kinase. This multidomain control over kinase activation state provides a structural mechanism to account for ITK's ability to tune the TCR signal.


Subject(s)
Lymphocyte Activation , Protein-Tyrosine Kinases/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Animals , Biomarkers , Humans , Lymphocyte Activation/immunology , Phospholipase C gamma/metabolism , Phosphorylation , Protein Binding , Protein Interaction Domains and Motifs , Protein-Tyrosine Kinases/chemistry , Receptors, Antigen, T-Cell/metabolism , Signal Transduction , src-Family Kinases/metabolism
2.
Trends Immunol ; 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-39060140

ABSTRACT

The guanine nucleotide exchange factor (GEF) VAV1, a previously 'undruggable' protein integral to T/B lymphocyte antigen-receptor signaling, promotes actin polymerization, immunological synapse formation, T cell activation and differentiation, and cytokine production. With the development of novel modalities for targeting proteins, we hypothesize that interventions targeting VAV1 will have therapeutic potential in T and T/B cell-mediated autoimmune and chronic inflammatory diseases. This opinion is supported by recent CRISPR-Cas9 studies showing VAV1 as a key positive regulator of T cell receptor (TCR) activation and cytokine production in primary human CD4+ and CD8+ T cells; data demonstrating that loss/suppression of VAV1 regulates autoimmunity and inflammation; and promising preclinical data from T and T/B cell-mediated disease models of arthritis and colitis showing the effectiveness of selective VAV1 targeting via protein degradation.

5.
Nat Immunol ; 13(5): 511-8, 2012 Apr 01.
Article in English | MEDLINE | ID: mdl-22473038

ABSTRACT

Innate γδ T cells function in the early phase of immune responses. Although innate γδ T cells have often been studied as one homogenous population, they can be functionally classified into effector subsets on the basis of the production of signature cytokines, analogous to adaptive helper T cell subsets. However, unlike the function of adaptive T cells, γδ effector T cell function correlates with genomically encoded T cell antigen receptor (TCR) chains, which suggests that clonal TCR selection is not the main determinant of the differentiation of γδ effector cells. A high-resolution transcriptome analysis of all emergent γδ thymocyte subsets segregated on the basis of use of the TCR γ-chain or δ-chain indicated the existence of three separate subtypes of γδ effector cells in the thymus. The immature γδ subsets were distinguished by unique transcription-factor modules that program effector function.


Subject(s)
Cell Differentiation/immunology , Receptors, Antigen, T-Cell, gamma-delta/genetics , Receptors, Antigen, T-Cell, gamma-delta/immunology , T-Lymphocyte Subsets/immunology , Thymus Gland/immunology , Transcriptome/immunology , Age Factors , Animals , CD24 Antigen/immunology , CD24 Antigen/metabolism , Cell Differentiation/genetics , Cell Lineage/immunology , Fetus/cytology , Fetus/immunology , Flow Cytometry , Interferon-gamma/immunology , Interferon-gamma/metabolism , Interleukin-17/immunology , Interleukin-17/metabolism , Mice , Mice, Inbred C57BL , Models, Immunological , Mycobacterium tuberculosis/immunology , Mycobacterium tuberculosis/metabolism , Principal Component Analysis , Receptors, Antigen, T-Cell, gamma-delta/classification , T-Lymphocyte Subsets/cytology , T-Lymphocyte Subsets/metabolism , Thymus Gland/cytology , Thymus Gland/metabolism , Transcription Factors/immunology , Transcription Factors/metabolism , Transcriptome/genetics
6.
Proc Natl Acad Sci U S A ; 118(35)2021 08 31.
Article in English | MEDLINE | ID: mdl-34452995

ABSTRACT

The strength of peptide:MHC interactions with the T cell receptor (TCR) is correlated with the time to first cell division, the relative scale of the effector cell response, and the graded expression of activation-associated proteins like IRF4. To regulate T cell activation programming, the TCR and the TCR proximal interleukin-2-inducible T cell kinase (ITK) simultaneously trigger many biochemically separate signaling cascades. T cells lacking ITK exhibit selective impairments in effector T cell responses after activation, but under the strongest signaling conditions, ITK activity is dispensable. To gain insight into whether TCR signal strength and ITK activity tune observed graded gene expression through the unequal activation of distinct signaling pathways, we examined Erk1/2 phosphorylation or nuclear factor of activated T cells (NFAT) and nuclear factor (NF)-κB translocation in naïve OT-I CD8+ cell nuclei. We observed the consistent digital activation of NFAT1 and Erk1/2, but NF-κB displayed dynamic, graded activation in response to variation in TCR signal strength, tunable by treatment with an ITK inhibitor. Inhibitor-treated cells showed the dampened induction of AP-1 factors Fos and Fosb, NF-κB response gene transcripts, and survival factor Il2 transcripts. ATAC sequencing analysis also revealed that genomic regions most sensitive to ITK inhibition were enriched for NF-κB and AP-1 motifs. Specific inhibition of NF-κB during peptide stimulation tuned the expression of early gene products like c-Fos. Together, these data indicate a key role for ITK in orchestrating the optimal activation of separate TCR downstream pathways, specifically aiding NF-κB activation. More broadly, we revealed a mechanism by which variations in TCR signal strength can produce patterns of graded gene expression in activated T cells.


Subject(s)
Protein-Tyrosine Kinases/metabolism , Receptors, Antigen, T-Cell/metabolism , Signal Transduction , T-Lymphocytes/metabolism , Animals , Cells, Cultured , DNA/metabolism , Female , Gene Expression Regulation , Lymphocyte Activation , MAP Kinase Signaling System/genetics , Male , Mice , NF-kappa B/metabolism , NFATC Transcription Factors/metabolism , Signal Transduction/genetics , T-Lymphocytes/enzymology , T-Lymphocytes/immunology
7.
Immunity ; 39(4): 661-75, 2013 Oct 17.
Article in English | MEDLINE | ID: mdl-24120360

ABSTRACT

The transcription factor Blimp-1 regulates the overall accumulation of virus-specific CD8⁺ T cells during acute viral infections. We found that increased proliferation and survival of Blimp-1-deficient CD8⁺ T cells resulted from sustained expression of CD25 and CD27 and persistent cytokine responsiveness. Silencing of Il2ra and Cd27 reduced the Blimp-1-deficient CD8⁺ T cell response. Genome-wide chromatin immunoprecipitation (ChIP) sequencing analysis identified Il2ra and Cd27 as direct targets of Blimp-1. At the peak of the antiviral response, but not earlier, Blimp-1 recruited the histone-modifying enzymes G9a and HDAC2 to the Il2ra and Cd27 loci, thereby repressing expression of these genes. In the absence of Blimp-1, Il2ra and Cd27 exhibited enhanced histone H3 acetylation and reduced histone H3K9 trimethylation. These data elucidate a central mechanism by which Blimp-1 acts as an epigenetic regulator and enhances the numbers of short-lived effector cells while suppressing the development of memory-precursor CD8⁺ T cells.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Epigenesis, Genetic/immunology , Lymphocytic Choriomeningitis/genetics , Lymphocytic choriomeningitis virus/immunology , Transcription Factors/genetics , Amino Acid Sequence , Animals , CD8-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/virology , Disease Progression , Histone Deacetylase 2/genetics , Histone Deacetylase 2/immunology , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/immunology , Histones/genetics , Histones/immunology , Humans , Immunologic Memory , Interleukin-2 Receptor alpha Subunit/antagonists & inhibitors , Interleukin-2 Receptor alpha Subunit/genetics , Interleukin-2 Receptor alpha Subunit/immunology , Lymphocytic Choriomeningitis/immunology , Lymphocytic Choriomeningitis/pathology , Lymphocytic Choriomeningitis/virology , Methylation , Mice , Mice, Transgenic , Molecular Sequence Data , Positive Regulatory Domain I-Binding Factor 1 , RNA, Small Interfering/genetics , RNA, Small Interfering/immunology , Signal Transduction , Transcription Factors/immunology , Tumor Necrosis Factor Receptor Superfamily, Member 7/antagonists & inhibitors , Tumor Necrosis Factor Receptor Superfamily, Member 7/genetics , Tumor Necrosis Factor Receptor Superfamily, Member 7/immunology
8.
Immunity ; 38(4): 681-93, 2013 Apr 18.
Article in English | MEDLINE | ID: mdl-23562159

ABSTRACT

How innate lymphoid cells (ILCs) in the thymus and gut become specialized effectors is unclear. The prototypic innate-like γδ T cells (Tγδ17) are a major source of interleukin-17 (IL-17). We demonstrate that Tγδ17 cells are programmed by a gene regulatory network consisting of a quartet of high-mobility group (HMG) box transcription factors, SOX4, SOX13, TCF1, and LEF1, and not by conventional TCR signaling. SOX4 and SOX13 directly regulated the two requisite Tγδ17 cell-specific genes, Rorc and Blk, whereas TCF1 and LEF1 countered the SOX proteins and induced genes of alternate effector subsets. The T cell lineage specification factor TCF1 was also indispensable for the generation of IL-22 producing gut NKp46(+) ILCs and restrained cytokine production by lymphoid tissue inducer-like effectors. These results indicate that similar gene network architecture programs innate sources of IL-17, independent of anatomical origins.


Subject(s)
High Mobility Group Proteins/metabolism , Interleukin-17/biosynthesis , Intestines/immunology , Lymphocyte Subsets/immunology , T-Lymphocytes/immunology , Animals , Antigens, Ly/metabolism , Autoantigens/genetics , Autoantigens/metabolism , Cell Differentiation/genetics , Cells, Cultured , Gene Regulatory Networks/immunology , Hepatocyte Nuclear Factor 1-alpha/genetics , Hepatocyte Nuclear Factor 1-alpha/metabolism , High Mobility Group Proteins/genetics , Immunity, Innate/genetics , Interleukin-17/genetics , Interleukins/immunology , Lymphoid Enhancer-Binding Factor 1/genetics , Lymphoid Enhancer-Binding Factor 1/metabolism , Mice , Mice, Knockout , Mice, Transgenic , Natural Cytotoxicity Triggering Receptor 1/metabolism , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , Receptors, Antigen, T-Cell, gamma-delta/metabolism , SOXC Transcription Factors/genetics , SOXC Transcription Factors/metabolism , Signal Transduction/immunology , Transcriptional Activation/immunology , Interleukin-22
9.
J Immunol ; 205(2): 335-345, 2020 07 15.
Article in English | MEDLINE | ID: mdl-32493815

ABSTRACT

TCR signal strength is critical for CD8+ T cell clonal expansion after Ag stimulation. Levels of the transcription factor IRF4 control the magnitude of this process through the induction of genes involved in proliferation and glycolytic metabolism. The signaling mechanism connecting graded TCR signaling to the generation of varying amounts of IRF4 is not well understood. In this study, we show that Ag potency regulates the kinetics but not the magnitude of NFAT1 activation in single mouse CD8+ T cells. Consequently, T cells that transduce weaker TCR signals exhibit a marked delay in Irf4 mRNA induction, resulting in decreased overall IRF4 expression in individual cells and increased heterogeneity within the clonal population. We further show that the activity of the tyrosine kinase ITK acts as a signaling catalyst that accelerates the rate of the cellular response to TCR stimulation, controlling the time to onset of Irf4 gene transcription. These findings provide insight into the function of ITK in TCR signal transduction that ultimately regulates IRF4 expression levels in response to variations in TCR signal strength.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Interferon Regulatory Factors/metabolism , Protein-Tyrosine Kinases/metabolism , Animals , Cell Proliferation , Cells, Cultured , Female , Gene Expression Regulation , Interferon Regulatory Factors/genetics , Lymphocyte Activation , Male , Mice , Mice, Knockout , Protein-Tyrosine Kinases/genetics , Receptors, Antigen, T-Cell/metabolism , Signal Transduction
10.
Immunity ; 34(4): 492-504, 2011 Apr 22.
Article in English | MEDLINE | ID: mdl-21497118

ABSTRACT

Polarized segregation of proteins in T cells is thought to play a role in diverse cellular functions including signal transduction, migration, and directed secretion of cytokines. Persistence of this polarization can result in asymmetric segregation of fate-determining proteins during cell division, which may enable a T cell to generate diverse progeny. Here, we provide evidence that a lineage-determining transcription factor, T-bet, underwent asymmetric organization in activated T cells preparing to divide and that it was unequally partitioned into the two daughter cells. This unequal acquisition of T-bet appeared to result from its asymmetric destruction during mitosis by virtue of concomitant asymmetric segregation of the proteasome. These results suggest a mechanism by which a cell may unequally localize cellular activities during division, thereby imparting disparity in the abundance of cell fate regulators in the daughter cells.


Subject(s)
Mitosis , Proteasome Endopeptidase Complex/metabolism , T-Box Domain Proteins/immunology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , Animals , Cell Polarity , Cells, Cultured , Mice , Mice, Inbred C57BL , Phosphorylation , T-Box Domain Proteins/metabolism , T-Lymphocytes/enzymology
11.
PLoS Pathog ; 13(8): e1006544, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28827827

ABSTRACT

Virus infections induce CD8+ T cell responses comprised of a large population of terminal effector cells and a smaller subset of long-lived memory cells. The transcription factors regulating the relative expansion versus the long-term survival potential of anti-viral CD8+ T cells are not completely understood. We identified ZBTB32 as a transcription factor that is transiently expressed in effector CD8+ T cells. After acute virus infection, CD8+ T cells deficient in ZBTB32 showed enhanced virus-specific CD8+ T cell responses, and generated increased numbers of virus-specific memory cells; in contrast, persistent expression of ZBTB32 suppressed memory cell formation. The dysregulation of CD8+ T cell responses in the absence of ZBTB32 was catastrophic, as Zbtb32-/- mice succumbed to a systemic viral infection and showed evidence of severe lung pathology. We found that ZBTB32 and Blimp-1 were co-expressed following CD8+ T cell activation, bound to each other, and cooperatively regulated Blimp-1 target genes Eomes and Cd27. These findings demonstrate that ZBTB32 is a key transcription factor in CD8+ effector T cells that is required for the balanced regulation of effector versus memory responses to infection.


Subject(s)
Arenaviridae Infections/immunology , CD8-Positive T-Lymphocytes/immunology , Immunologic Memory/immunology , Repressor Proteins/immunology , Adoptive Transfer , Animals , Chromatin Immunoprecipitation , Disease Models, Animal , Flow Cytometry , Lymphocyte Activation/immunology , Lymphocytic choriomeningitis virus/immunology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Microscopy, Confocal , Polymerase Chain Reaction , Repressor Proteins/biosynthesis
12.
J Immunol ; 198(3): 1142-1155, 2017 02 01.
Article in English | MEDLINE | ID: mdl-28031335

ABSTRACT

CD4 T cells can differentiate into multiple effector subsets, including ThCTL that mediate MHC class II-restricted cytotoxicity. Although CD4 T cell-mediated cytotoxicity has been reported in multiple viral infections, their characteristics and the factors regulating their generation are unclear, in part due to a lack of a signature marker. We show in this article that, in mice, NKG2C/E identifies the ThCTL that develop in the lung during influenza A virus infection. ThCTL express the NKG2X/CD94 complex, in particular the NKG2C/E isoforms. NKG2C/E+ ThCTL are part of the lung CD4 effector population, and they mediate influenza A virus-specific cytotoxic activity. The phenotype of NKG2C/E+ ThCTL indicates they are highly activated effectors expressing high levels of binding to P-selectin, T-bet, and Blimp-1, and that more of them secrete IFN-γ and readily degranulate than non-ThCTL. ThCTL also express more cytotoxicity-associated genes including perforin and granzymes, and fewer genes associated with recirculation and memory. They are found only at the site of infection and not in other peripheral sites. These data suggest ThCTL are marked by the expression of NKG2C/E and represent a unique CD4 effector population specialized for cytotoxicity.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Cytotoxicity, Immunologic , Influenza A virus , NK Cell Lectin-Like Receptor Subfamily C/analysis , Orthomyxoviridae Infections/immunology , Animals , Biomarkers/analysis , CD4-Positive T-Lymphocytes/chemistry , CD4-Positive T-Lymphocytes/classification , Interferon-gamma/biosynthesis , Lung/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Positive Regulatory Domain I-Binding Factor 1 , Transcription Factors/analysis
14.
Proc Natl Acad Sci U S A ; 112(7): E710-7, 2015 Feb 17.
Article in English | MEDLINE | ID: mdl-25646421

ABSTRACT

Cytosolic DNA-sensing pathways that signal via Stimulator of interferon genes (STING) mediate immunity to pathogens and also promote autoimmune pathology in DNaseII- and DNaseIII-deficient mice. In contrast, we report here that STING potently suppresses inflammation in a model of systemic lupus erythematosus (SLE). Lymphoid hypertrophy, autoantibody production, serum cytokine levels, and other indicators of immune activation were markedly increased in STING-deficient autoimmune-prone mice compared with STING-sufficient littermates. As a result, STING-deficient autoimmune-prone mice had significantly shorter lifespans than controls. Importantly, Toll-like receptor (TLR)-dependent systemic inflammation during 2,6,10,14-tetramethylpentadecane (TMPD)-mediated peritonitis was similarly aggravated in STING-deficient mice. Mechanistically, STING-deficient macrophages failed to express negative regulators of immune activation and thus were hyperresponsive to TLR ligands, producing abnormally high levels of proinflammatory cytokines. This hyperreactivity corresponds to dramatically elevated numbers of inflammatory macrophages and granulocytes in vivo. Collectively these findings reveal an unexpected negative regulatory role for STING, having important implications for STING-directed therapies.


Subject(s)
Autoimmunity/physiology , Membrane Proteins/physiology , Animals , Autoantibodies/biosynthesis , Dendritic Cells/immunology , Gene Expression Regulation/physiology , Interferon Regulatory Factor-3/genetics , Interferon Regulatory Factor-3/physiology , Interferons/physiology , Lymphocyte Activation , Membrane Proteins/genetics , Mice
15.
Nat Rev Immunol ; 7(6): 479-85, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17479128

ABSTRACT

Recent data from three laboratories have identified the TEC kinases, ITK and RLK, as crucial regulators of CD8(+) T-cell development into the conventional lymphocyte lineage. In the absence of ITK and RLK, CD4(+)CD8(+) thymocytes upregulate the T-box transcription factor eomesodermin, and develop into mature CD8(+) T cells that resemble memory cells, exhibit immediate effector cytokine production and depend on IL-15. Furthermore, the selection of these non-conventional 'innate' T cells results from interactions with haematopoietic cells in the thymus. These findings lead to the hypothesis that altered TCR signalling, together with distinct co-stimulatory signals, is the basis for the development of non-conventional T-cell lineages.


Subject(s)
CD8-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/immunology , Models, Immunological , Protein-Tyrosine Kinases/immunology , Signal Transduction/immunology , Animals , Cell Differentiation/immunology , Cell Lineage , Humans , Immunity, Innate
16.
Immunity ; 28(6): 763-73, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18549798

ABSTRACT

Differentiation of naive CD4+ T cells into T helper type 1 (Th1) effector cells requires both T cell receptor (TCR) signaling and cytokines such as interleukin-12 and interferon gamma (IFN-gamma). Here, we report that a third cytokine signal, mediated by the Janus family tyrosine kinase 3 (Jak3) and signal transducer and activator of transcription 5 (STAT5) pathway, is also required for Th1 cell differentiation. In the absence of Jak3-dependent signals, naive CD4+ T cells proliferate robustly but produce little IFN-gamma after Th1 cell polarization in vitro. This defect is not due to reduced activation of STAT1 or STAT4 or to impaired upregulation of the transcription factor T-bet. Instead, we find that T-bet binding to the Ifng promoter is greatly diminished in the absence of Jak3-dependent signals, correlating with a decrease in Ifng promoter accessibility and histone acetylation. These data indicate that Jak3 regulates epigenetic modification and chromatin remodeling of the Ifng locus during Th1 cell differentiation.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , Chromatin Assembly and Disassembly , Cytokines/metabolism , Interferon-gamma/genetics , Janus Kinase 3/metabolism , Th1 Cells/cytology , Th1 Cells/metabolism , Animals , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/immunology , Cell Differentiation , Cytokines/immunology , Epigenesis, Genetic , Interferon-gamma/immunology , Interferon-gamma/metabolism , Mice , Mice, Mutant Strains , Promoter Regions, Genetic , STAT Transcription Factors/metabolism , STAT5 Transcription Factor/metabolism , Signal Transduction , Th1 Cells/immunology
17.
J Immunol ; 195(10): 4822-31, 2015 Nov 15.
Article in English | MEDLINE | ID: mdl-26466958

ABSTRACT

In T cells, the Tec kinases IL-2-inducible T cell kinase (ITK) and resting lymphocyte kinase (RLK) are activated by TCR stimulation and are required for optimal downstream signaling. Studies of CD4(+) T cells from Itk(-/-) and Itk(-/-)Rlk(-/-) mice have indicated differential roles of ITK and RLK in Th1, Th2, and Th17 differentiation and cytokine production. However, these findings are confounded by the complex T cell developmental defects in these mice. In this study, we examine the consequences of ITK and RLK inhibition using a highly selective and potent small molecule covalent inhibitor PRN694. In vitro Th polarization experiments indicate that PRN694 is a potent inhibitor of Th1 and Th17 differentiation and cytokine production. Using a T cell adoptive transfer model of colitis, we find that in vivo administration of PRN694 markedly reduces disease progression, T cell infiltration into the intestinal lamina propria, and IFN-γ production by colitogenic CD4(+) T cells. Consistent with these findings, Th1 and Th17 cells differentiated in the presence of PRN694 show reduced P-selectin binding and impaired migration to CXCL11 and CCL20, respectively. Taken together, these data indicate that ITK plus RLK inhibition may have therapeutic potential in Th1-mediated inflammatory diseases.


Subject(s)
Cell Differentiation/drug effects , Colitis/prevention & control , Protein Kinase Inhibitors/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/immunology , Th1 Cells/immunology , Animals , Cell Differentiation/genetics , Cell Differentiation/immunology , Chemokine CCL20/genetics , Chemokine CCL20/immunology , Chemokine CXCL11/genetics , Chemokine CXCL11/immunology , Colitis/genetics , Colitis/immunology , Colitis/pathology , Interferon-gamma/genetics , Interferon-gamma/immunology , Mice , Mice, Knockout , Protein-Tyrosine Kinases/genetics , Th1 Cells/pathology , Th17 Cells/immunology , Th17 Cells/pathology
18.
J Immunol ; 192(12): 5881-93, 2014 Jun 15.
Article in English | MEDLINE | ID: mdl-24835398

ABSTRACT

In response to acute virus infections, CD8(+) T cells differentiate to form a large population of short-lived effectors and a stable pool of long-lived memory cells. The characteristics of the CD8(+) T cell response are influenced by TCR affinity, Ag dose, and the inflammatory cytokine milieu dictated by the infection. To address the mechanism by which differences in TCR signal strength could regulate CD8(+) T cell differentiation, we investigated the transcription factor, IFN regulatory factor 4 (IRF4). We show that IRF4 is transiently upregulated to differing levels in murine CD8(+) T cells, based on the strength of TCR signaling. In turn, IRF4 controls the magnitude of the CD8(+) T cell response to acute virus infection in a dose-dependent manner. Modest differences in IRF4 expression dramatically influence the numbers of short-lived effector cells at the peak of the infection, but have no impact on the kinetics of the infection or on the rate of T cell contraction. Furthermore, the expression of key transcription factors such as T cell factor 1 and Eomesodermin are highly sensitive to graded levels of IRF4. In contrast, T-bet expression is less dependent on IRF4 levels and is influenced by the nature of the infection. These data indicate that IRF4 is a key component that translates the strength of TCR signaling into a graded response of virus-specific CD8(+) T cells.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Cell Differentiation/immunology , Cell Proliferation , Influenza A virus/immunology , Interferon Regulatory Factors/immunology , Lymphocytic Choriomeningitis/immunology , Lymphocytic choriomeningitis virus/immunology , Orthomyxoviridae Infections/immunology , Acute Disease , Animals , CD8-Positive T-Lymphocytes/pathology , Cell Differentiation/genetics , Influenza A virus/genetics , Interferon Regulatory Factors/genetics , Lymphocytic Choriomeningitis/genetics , Lymphocytic choriomeningitis virus/genetics , Mice , Mice, Knockout , Orthomyxoviridae Infections/genetics , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/immunology , Signal Transduction/genetics , Signal Transduction/immunology , Up-Regulation/genetics , Up-Regulation/immunology
19.
J Immunol ; 193(2): 688-99, 2014 Jul 15.
Article in English | MEDLINE | ID: mdl-24943215

ABSTRACT

T cell development in the thymus produces multiple lineages of cells, including innate T cells such as γδ TCR(+) cells, invariant NKT cells, mucosal-associated invariant T cells, and H2-M3-specific cells. Although innate cells are generally a minor subset of thymocytes, in several strains of mice harboring mutations in T cell signaling proteins or transcriptional regulators, conventional CD8(+) T cells develop as innate cells with characteristics of memory T cells. Thus, in Itk-deficient mice, mature CD4(-)CD8(+) (CD8 single-positive [SP]) thymocytes express high levels of the transcription factor eomesodermin (Eomes) and are dependent on IL-4 being produced in the thymic environment by a poorly characterized subset of CD4(+) thymocytes expressing the transcriptional regulator promyelocytic leukemia zinc finger. In this study, we show that a sizeable proportion of mature CD4(+)CD8(-) (CD4SP) thymocytes in itk(-/-) mice also develop as innate Eomes-expressing T cells. These cells are dependent on MHC class II and IL-4 signaling for their development, indicating that they are conventional CD4(+) T cells that have been converted to an innate phenotype. Surprisingly, neither CD4SP nor CD8SP innate Eomes(+) thymocytes in itk(-/-) or SLP-76(Y145F) mice are dependent on γδ T cells for their development. Instead, we find that the predominant population of Eomes(+) innate itk(-/-) CD4SP thymocytes is largely absent in mice lacking CD1d-specific invariant NKT cells, with no effect on innate itk(-/-) CD8SP thymocytes. In contrast, both subsets of innate Eomes(+)itk(-/-) T cells require the presence of a novel promyelocytic leukemia zinc finger-expressing, SLAM family receptor adapter protein-dependent thymocyte population that is essential for the conversion of conventional CD4(+) and CD8(+) T cells into innate T cells with a memory phenotype.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Protein-Tyrosine Kinases/immunology , Signal Transduction/immunology , Animals , Antigens, CD1d/immunology , Antigens, CD1d/metabolism , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Cell Differentiation/genetics , Cell Differentiation/immunology , Cell Proliferation , Flow Cytometry , Interleukin-15/deficiency , Interleukin-15/genetics , Interleukin-15/immunology , Interleukin-4/immunology , Interleukin-4/metabolism , Kruppel-Like Transcription Factors/immunology , Kruppel-Like Transcription Factors/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Natural Killer T-Cells/immunology , Natural Killer T-Cells/metabolism , Promyelocytic Leukemia Zinc Finger Protein , Protein-Tyrosine Kinases/deficiency , Protein-Tyrosine Kinases/genetics , Rats , Receptors, Antigen, T-Cell, alpha-beta/immunology , Receptors, Antigen, T-Cell, alpha-beta/metabolism , Receptors, Antigen, T-Cell, gamma-delta/immunology , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Signal Transduction/genetics , T-Box Domain Proteins/immunology , T-Box Domain Proteins/metabolism , Thymocytes/immunology , Thymocytes/metabolism
20.
J Immunol ; 193(2): 673-87, 2014 Jul 15.
Article in English | MEDLINE | ID: mdl-24928994

ABSTRACT

T cell development in the thymus produces multiple lineages of cells, including innate T cells. Studies in mice harboring alterations in TCR signaling proteins or transcriptional regulators have revealed an expanded population of CD4(+) innate T cells in the thymus that produce IL-4 and express the transcription factor promyelocytic leukemia zinc finger (PLZF). In these mice, IL-4 produced by the CD4(+)PLZF(+) T cell population leads to the conversion of conventional CD8(+) thymocytes into innate CD8(+) T cells resembling memory T cells expressing eomesodermin. The expression of PLZF, the signature invariant NKT cell transcription factor, in these innate CD4(+) T cells suggests that they might be a subset of αß or γδ TCR(+) NKT cells or mucosal-associated invariant T (MAIT) cells. To address these possibilities, we characterized the CD4(+)PLZF(+) innate T cells in itk(-/-) mice. We show that itk(-/-) innate PLZF(+)CD4(+) T cells are not CD1d-dependent NKT cells, MR1-dependent MAIT cells, or γδ T cells. Furthermore, although the itk(-/-) innate PLZF(+)CD4(+) T cells express αß TCRs, neither ß2-microglobulin-dependent MHC class I nor any MHC class II molecules are required for their development. In contrast to invariant NKT cells and MAIT cells, this population has a highly diverse TCRα-chain repertoire. Analysis of peripheral tissues indicates that itk(-/-) innate PLZF(+)CD4(+) T cells preferentially home to spleen and mesenteric lymph nodes owing to increased expression of gut-homing receptors, and that their expansion is regulated by commensal gut flora. These data support the conclusion that itk(-/-) innate PLZF(+)CD4(+) T cells are a novel subset of innate T cells.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Cell Differentiation/immunology , Cell Proliferation , Kruppel-Like Transcription Factors/immunology , Protein-Tyrosine Kinases/immunology , Receptors, Antigen, T-Cell, alpha-beta/immunology , Animals , Antigens, CD1d/immunology , Antigens, CD1d/metabolism , CD4-Positive T-Lymphocytes/metabolism , Cell Differentiation/genetics , Cells, Cultured , Flow Cytometry , Gene Expression/immunology , H-2 Antigens/genetics , H-2 Antigens/immunology , H-2 Antigens/metabolism , Interleukin-4/genetics , Interleukin-4/immunology , Interleukin-4/metabolism , Kruppel-Like Transcription Factors/metabolism , Lymph Nodes/immunology , Lymph Nodes/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Promyelocytic Leukemia Zinc Finger Protein , Protein-Tyrosine Kinases/deficiency , Protein-Tyrosine Kinases/genetics , Receptors, Antigen, T-Cell, alpha-beta/genetics , Receptors, Antigen, T-Cell, alpha-beta/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Spleen/immunology , Spleen/metabolism , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Thymocytes/immunology , Thymocytes/metabolism , beta 2-Microglobulin/immunology , beta 2-Microglobulin/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL