Similar Datasets
Project description:Gamma Delta (gd) T cells play unique protective roles in different settings of acute and chronic infections. However, what they respond to and how they function in the acute versus chronic phases of the same infection remains unclear. It is well documented that cytolytic gd T cells that express Vg9Vd2 TCRs and respond to phosphoantigens (pAgs) expand in acute Mycobacterium tuberculosis (Mtb) infection in humans. However, most infections with Mtb manifest as a chronic, clinically asymptomatic state. While past work indicates that gd T cells contribute to Mtb infection control, their response during this phase of Mtb infection is not well understood. Here, we analyze peripheral blood gd T cells from a South African adolescent cohort and show that a unique CD8+ gd T cell subset with features of “memory inflation” expand in chronic Mtb infection. Using targeted scRNA-seq coupled with surface protein expression and multiparametric single cell pseudotime trajectory analysis, we identify the differentiation paths that these CD8+ gd T cells follow to develop into effectors in this infection state.
2022-10-31 | GSE216654 | GEO
Project description:Gamma Delta (gd) T cells play unique protective roles in different settings of acute and chronic infections. However, what they respond to and how they function in the acute versus chronic phases of the same infection remains unclear. It is well documented that cytolytic gd T cells that express Vg9Vd2 TCRs and respond to phosphoantigens (pAgs) expand in acute Mycobacterium tuberculosis (Mtb) infection in humans. However, most infections with Mtb manifest as a chronic, clinically asymptomatic state. While past work indicates that gd T cells contribute to Mtb infection control, their response during this phase of Mtb infection is not well understood. Here, we analyze peripheral blood gd T cells from a South African adolescent cohort and show that a unique CD8+ gd T cell subset with features of “memory inflation” expand in chronic Mtb infection.
2022-10-31 | GSE216652 | GEO
Project description:Osteoclasts (OCs) and much less dendritic cells (DCs) induce significant expansion and functional activation of NK cells, and furthermore, the OC-expanded NK cells preferentially increase the expansion and activation of CD8+ T cells by targeting CD4+ T cells. When autologous OCs were used to expand patient NK cells much lower percentages of expanded CD8+ T cells, decreased numbers of expanded NK cells and decreased functions of NK cells could be observed, and the addition of allogeneic healthy OCs increased the patients' NK function. Mechanistically, OC-expanded NK cells were found to lyse CD4+ T cells but not CD8+ T cells suggesting potential selection of CD8+ T cells before their expansion by OC activated NK cells. In agreement, Increased IFN-γ secretion, and NK cell-mediated cytotoxicity and higher percentages of CD8+ T cells, in various tissue compartments of oral tumor-bearing hu-BLT mice in response to immunotherapy by OC-expanded NK cells were observed. Thus, our results indicate an important relationship between NK and CD8+ T cells.
| S-EPMC7683603 | biostudies-literature
Project description:Polymorphisms in the type III interferon IFN-?3 and the killer cell immunoglobulin-like receptor (KIR) genes controlling the activity of natural killer (NK) cells can predict spontaneous resolution of acute hepatitis C virus (HCV) infection. We hypothesized that IFN-?3 polymorphism may modulate NK cell function during acute HCV.We monitored the plasma levels of type III IFNs in relation to the phenotype and the function of NK cells in a cohort of people who inject drugs (PWID) during acute HCV infection with different outcomes.Early acute HCV was associated with high variability in type III IFNs plasma levels and the favorable IFN-?3 CC genotype was associated with higher viral loads. Reduced expression of Natural Killer Group Protein 2A (NKG2A) was associated with lower IFN-?3 plasma levels and the CC genotype. IFN-? production by NK cells was higher in individuals with the CC genotype during acute infection but this did not prevent viral persistence. IFN-?3 plasma levels did not correlate with function of NK cells and IFN-?3 prestimulation did not affect NK cell activation and function.These results suggest that IFN-?3 polymorphism indirectly influences NK cell phenotype and function during acute HCV but other factors may act in concert to determine the outcome of the infection.
| S-EPMC5004291 | biostudies-literature
Project description:Inhibition of type 1 interferon (IFN-I) signaling promotes the control of persistent virus infection, but the underlying mechanisms remain poorly understood. Here, we report that genetic ablation of Ifnar1 specifically in natural killer (NK) cells led to elevated numbers of T follicular helper cells, germinal center B cells, and plasma cells and improved antiviral T cell function, resulting in hastened virus clearance that was comparable to IFNAR1 neutralizing antibody treatment. Antigen-specific B cells and antiviral antibodies were essential for the accelerated control of LCMV Cl13 infection following IFNAR1 blockade. IFNAR1 signaling in NK cells promoted NK cell function and general killing of antigen-specific CD4 and CD8 T cells. Therefore, inhibition of IFN-I signaling in NK cells enhances CD4 and CD8 T cell responses, promotes humoral immune responses, and thereby facilitates the control of persistent virus infection.
| S-EPMC7997497 | biostudies-literature
Project description:Innate memory phenotype (IMP) CD8(+) T cells are nonconventional ?? T cells exhibiting features of innate immune cells and are significantly increased in the absence of ITK. Their developmental path and function are not clear. In this study, we show hematopoietic MHC class I (MHCI)-dependent generation of Ag-specific IMP CD8(+) T cells using bone marrow chimeras. Wild-type bone marrow gives rise to IMP CD8(+) T cells in MHCI(-/-) recipients, resembling those in Itk(-/-) mice, but distinct from those derived via homeostatic proliferation, and independent of recipient thymus. In contrast, MHCI(-/-) bone marrow does not lead to IMP CD8(+) T cells in wild-type recipients. OTI IMP CD8(+) T cells generated via this method exhibited enhanced early response to Ag without prior primary stimulation. Our findings suggest a method to generate Ag-specific "naive" CD8(+) IMP T cells, as well as demonstrate that they are not homeostatic proliferation cells and can respond promptly in an Ag-specific fashion.
| S-EPMC4033301 | biostudies-literature
Project description:The anti-Müllerian hormone triggers the regression of uterus and fallopian tubes in male embryos; if there are problems in the synthesis or action of this protein, Müllerian structures persist in an otherwise phenotypic male. The most frequent clinical presentation of Persistent Mullerian Duct syndrome is cryptorchidism and inguinal hernia. The few cases reported in adults are incidental findings or inguinal hernias. However, we present an adult male with history of bilateral cryptorchidism with unsuccessful orchidopexy, who presents with a large abdominal mass with the finding of a seminomatous tumor and persistence of Müllerian structures, in whom the variant c.916delC (p.Leu306Cysfs*29) in the AMHR2 gene not previously reported was documented.
| S-EPMC6844334 | biostudies-literature
Project description:Pregnant women are particularly susceptible to complications of influenza A virus infection, which may result from pregnancy-induced changes in the function of immune cells, including natural killer (NK) cells. To better understand NK cell function during pregnancy, we assessed the ability of the two main subsets of NK cells, CD56dim, and CD56bright NK cells, to respond to influenza-virus infected cells and tumor cells. During pregnancy, CD56dim and CD56bright NK cells displayed enhanced functional responses to both infected and tumor cells, with increased expression of degranulation markers and elevated frequency of NK cells producing IFN-?. To better understand the mechanisms driving this enhanced function, we profiled CD56dim and CD56bright NK cells from pregnant and non-pregnant women using mass cytometry. NK cells from pregnant women displayed significantly increased expression of several functional and activation markers such as CD38 on both subsets and NKp46 on CD56dim NK cells. NK cells also displayed diminished expression of the chemokine receptor CXCR3 during pregnancy. Overall, these data demonstrate that functional and phenotypic shifts occur in NK cells during pregnancy that can influence the magnitude of the immune response to both infections and tumors.
| S-EPMC6820503 | biostudies-literature
Project description:The number of naive T cells decreases and susceptibility to new microbial infections increases with age. Here we describe a previously unknown subset of phenotypically naive human CD8(+) T cells that rapidly secreted multiple cytokines in response to persistent viral antigens but differed transcriptionally from memory and effector T cells. The frequency of these CD8(+) T cells, called 'memory T cells with a naive phenotype' (TMNP cells), increased with age and after severe acute infection and inversely correlated with the residual capacity of the immune system to respond to new infections with age. CD8(+) TMNP cells represent a potential new target for the immunotherapy of persistent infections and should be accounted for and subtracted from the naive pool if truly naive T cells are needed to respond to antigens.
| S-EPMC4955715 | biostudies-literature
Project description:The human lung T cell compartment contains many CD8? T cells specific for respiratory viruses, suggesting that the lung is protected from recurring respiratory infections by a resident T cell pool. The entry site for respiratory viruses is the epithelium, in which a subset of lung CD8? T cells expressing CD103 (?E integrin) resides. Here, we determined the specificity and function of CD103?CD8? T cells in protecting human lung against viral infection. Mononuclear cells were isolated from human blood and lung resection samples. Variable numbers of CD103?CD8? T cells were retrieved from the lung tissue. Interestingly, expression of CD103 was seen only in lung CD8? T cells specific for influenza but not in those specific for EBV or CMV. CD103? and influenza-reactive cells preferentially expressed NKG2A, an inhibitor of CD8? T cell cytotoxic function. In contrast to CD103?CD8? T cells, most CD103?CD8? cells did not contain perforin or granzyme B. However, they could quickly upregulate these cytotoxic mediators when exposed to a type I IFN milieu or via contact with their specific antigen. This mechanism may provide a rapid and efficient response to influenza infection, without inducing cytotoxic damage to the delicate epithelial barrier.
| S-EPMC3104744 | biostudies-literature