Toll like Receptor 2 engagement on CD4+T cells promotes TH9 differentiation and function

Abstract Defects of the common gamma chain subunit of the cytokine receptors (γc) or of Jak3, a tyrosine kinase required for γc signal transduction, result in T−B+ severe combined immunodeficiency (SCID). However, atypical cases, characterized by progressive development of T lymphocytes, have been also reported. We describe a child with SCID caused by Jak3 gene defects, which strongly but not completely affect Jak3 protein expression and function, who developed a substantial number (>3,000/μL) of autologous CD3+CD4+ T cells. These cells showed a primed/activated phenotype (CD45R0+ Fas+HLA-DR+ CD62Llo), defective secretion of T-helper 1 and T-helper 2 cytokines, reduced proliferation to mitogens, and a high in vitro susceptibility to spontaneous (caused by downregulation of bcl-2 expression) as well as activation-induced cell death. A restricted T-cell receptor repertoire was observed, with oligoclonal expansion within each of the dominant segments. These features resemble those observed in γc-/y and in Jak3−/−mice, in which a population of activated, anergic T cells (predominantly CD4+) also develops with age. These results suggest that residual Jak3 expression and function or other Jak3-independent signals may also permit the generation of CD4+ T cells that undergo in vivo clonal expansion in humans; however, these mechanisms do not allow development of CD8+ T cells, nor do they fully restore the functional properties of CD4+ T lymphocytes.

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Differential Expression and Function of α-Mannosidase I in Stimulated Naive and Memory CD4+ T Cells

Journal of Immunotherapy ◽

10.1097/cji.0b013e31821dcf23 ◽

2011 ◽

Vol 34 (5) ◽

pp. 428-437 ◽

Cited By ~ 8

Author(s):

Inga Gebuhr ◽

Kathrin Keeren ◽

Katrin Vogt ◽

Conny Höflich ◽

Christine Appelt ◽

...

Keyword(s):

T Cells ◽

Differential Expression ◽

Cd4 T Cells ◽

And Function ◽

Memory Cd4 T Cells

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Protective effect of Lactobacillus reuteri DSM 17938 against experimental necrotizing enterocolitis is mediated by Toll-like receptor 2

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00084.2017 ◽

2018 ◽

Vol 315 (2) ◽

pp. G231-G240 ◽

Cited By ~ 13

Author(s):

Thomas K. Hoang ◽

Baokun He ◽

Ting Wang ◽

Dat Q. Tran ◽

J. Marc Rhoads ◽

...

Keyword(s):

T Cells ◽

Necrotizing Enterocolitis ◽

Immune Modulation ◽

Lactobacillus Reuteri ◽

Inflammatory Responses ◽

Cow Milk ◽

Toll Like Receptor ◽

Toll Like Receptor 2 ◽

Anti Inflammatory

Lactobacillus reuteri DSM 17938 (LR 17938) has been shown to reduce the incidence and severity of necrotizing enterocolitis (NEC). It is unclear if preventing NEC by LR 17938 is mediated by Toll-like receptor 2 (TLR2), which is known to mediate proinflammatory responses to bacterial cell wall components. NEC was induced in newborn TLR2−/− or wild-type (WT) mice by the combination of gavage-feeding cow milk-based formula and exposure to hypoxia and cold stress. Treatment groups were administered formula supplemented with LR 17938 or placebo (deMan-Rogosa-Sharpe media). We observed that LR 17938 significantly reduced the incidence of NEC and reduced the percentage of activated effector CD4+T cells, while increasing Foxp3+ regulatory T cells in the intestinal mucosa of WT mice with NEC, but not in TLR2−/− mice. Dendritic cell (DC) activation by LR 17938 was mediated by TLR2. The percentage of tolerogenic DC in the intestine of WT mice was increased by LR 17938 treatment during NEC, a finding not observed in TLR2−/− mice. Furthermore, gut levels of proinflammatory cytokines IL-1β and IFN-γ were decreased after treatment with LR 17938 in WT mice but not in TLR2−/− mice. In conclusion, the combined in vivo and in vitro findings suggest that TLR2 receptors are involved in DC recognition and DC-priming of T cells to protect against NEC after oral administration of LR 17938. Our studies further clarify a major mechanism of probiotic LR 17938 action in preventing NEC by showing that neonatal immune modulation of LR 17938 is mediated by a mechanism requiring TLR2. NEW & NOTEWORTHY Lactobacillus reuteri DSM 17938 (LR 17938) has been shown to protect against necrotizing enterocolitis (NEC) in neonates and in neonatal animal models. The role of Toll-like receptor 2 (TLR2) as a sensor for gram-positive probiotics, activating downstream anti-inflammatory responses is unclear. Our current studies examined TLR2 −/− mice subjected to experimental NEC and demonstrated that the anti-inflammatory effects of LR 17938 are mediated via a mechanism requiring TLR2.

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T-bet represses collagen-induced arthritis by suppressing Th17 lineage commitment through inhibition of RORγt expression and function

Scientific Reports ◽

10.1038/s41598-021-96699-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Masaru Shimizu ◽

Yuya Kondo ◽

Reona Tanimura ◽

Kotona Furuyama ◽

Masahiro Yokosawa ◽

...

Keyword(s):

T Cells ◽

Cd4 T Cells ◽

T Helper 1 ◽

Collagen Induced Arthritis ◽

Over Expression ◽

Th17 Differentiation ◽

And Function ◽

Arthritic Joints

AbstractT-bet is a key transcription factor for the T helper 1 lineage and its expression level is negatively correlated to inflammation in patients with rheumatoid arthritis (RA). Our previous study using T-bet transgenic mice revealed over-expression of T-bet completely suppressed collagen-induced arthritis (CIA), a murine model of RA, indicating a potential suppressive role of T-bet in the pathogenesis of autoimmune arthritis. Here, we show T-bet-deficiency exacerbated CIA. T-bet in CD4 + T cells, but not in CD11c + dendritic cells, was critical for regulating the production of IL-17A, IL-17F, IL-22, and TNFα from CD4 + T cells. T-bet-deficient CD4 + T cells showed higher RORγt expression and increased IL-17A production in RORγt-positive cells after CII immunization. In addition, T-bet-deficient naïve CD4 + T cells showed accelerated Th17 differentiation in vitro. CIA induced in CD4-Cre T-betfl/fl (cKO) mice was more severe and T-bet-deficient CD4 + T cells in the arthritic joints of cKO mice showed higher RORγt expression and increased IL-17A production. Transcriptome analysis of T-bet-deficient CD4 + T cells revealed that expression levels of Th17-related genes were selectively increased. Our results indicate that T-bet in CD4 + T cells repressed RORγt expression and function resulting in suppression of arthritogenic Th17 cells and CIA.

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