Project description:T follicular helper cells (TFH) are critical for the development and maintenance of germinal centers (GC) and humoral immune responses. During chronic HIV/SIV infection TFH accumulate, possibly as a result of antigen persistence. The HIV/SIV-associated TFH expansion may also reflect lack of regulation by suppressive follicular regulatory CD4+ T-cells (TFR). TFR are natural regulatory T-cells (TREG) that migrate into the follicle and, similarly to TFH, up-regulate CXCR5, Bcl-6, and PD1. Here we identified TFR as CD4+CD25+FoxP3+CXCR5+PD1hiBcl-6+ within lymph nodes of rhesus macaques (RM) and confirmed their localization within the GC by immunohistochemistry. RNA sequencing showed that TFR exhibit a distinct transcriptional profile with shared features of both TFH and TREG, including intermediate expression of FoxP3, Bcl-6, PRDM1, IL-10, and IL-21. In healthy, SIV-uninfected RM, we observed a negative correlation between frequencies of TFR and both TFH and GC B-cells as well as levels of CD4+ T-cell proliferation. Following SIV infection, the TFR/TFH ratio was reduced with no change in the frequency of TREG or TFR within the total CD4+ T-cell pool. Finally, we examined whether higher levels of direct virus infection of TFR were responsible for their relative depletion post-SIV infection. We found that TFH, TFR and TREG sorted from SIV- infected RM harbor comparable levels of cell-associated viral DNA. Our data suggests that TFR may contribute to the regulation and proliferation of TFH and GC B-cells in vivo and that a decreased TFR/TFH ratio in chronic SIV infection may lead to unchecked expansion of both TFH and GC B-cells. TFR, TFH, TREG and bulk CD4 cells were sorted from spleens of 5 uninfected and 5 infected RM.
Project description:T follicular helper cells (TFH) are critical for the development and maintenance of germinal centers (GC) and humoral immune responses. During chronic HIV/SIV infection TFH accumulate, possibly as a result of antigen persistence. The HIV/SIV-associated TFH expansion may also reflect lack of regulation by suppressive follicular regulatory CD4+ T-cells (TFR). TFR are natural regulatory T-cells (TREG) that migrate into the follicle and, similarly to TFH, up-regulate CXCR5, Bcl-6, and PD1. Here we identified TFR as CD4+CD25+FoxP3+CXCR5+PD1hiBcl-6+ within lymph nodes of rhesus macaques (RM) and confirmed their localization within the GC by immunohistochemistry. RNA sequencing showed that TFR exhibit a distinct transcriptional profile with shared features of both TFH and TREG, including intermediate expression of FoxP3, Bcl-6, PRDM1, IL-10, and IL-21. In healthy, SIV-uninfected RM, we observed a negative correlation between frequencies of TFR and both TFH and GC B-cells as well as levels of CD4+ T-cell proliferation. Following SIV infection, the TFR/TFH ratio was reduced with no change in the frequency of TREG or TFR within the total CD4+ T-cell pool. Finally, we examined whether higher levels of direct virus infection of TFR were responsible for their relative depletion post-SIV infection. We found that TFH, TFR and TREG sorted from SIV- infected RM harbor comparable levels of cell-associated viral DNA. Our data suggests that TFR may contribute to the regulation and proliferation of TFH and GC B-cells in vivo and that a decreased TFR/TFH ratio in chronic SIV infection may lead to unchecked expansion of both TFH and GC B-cells.
Project description:The datasets were obtained to investigate the transcriptional profile of Tfh, Tfr and Treg cells isolated from different human tissues. The comparison between lymphoid tissues with different frequency of the most mature Tfh and Tfr cells allows the investigation of maturation as well as tissue adaptation of those different cell subsets. To address these issues, three different cell populations from three different tissues were sorted by index sorting, with Tfh cells as CD4+CXCR5+ICOS+; Tfr cells as CD4+CXCR5+CD25+ and Treg cells as CD4+CXCR5-CD25+. Smart-seq2 protocol was used mRNA library preparations.
Project description:T follicular helper (Tfh) cells, essential for germinal center reactions, are not identical, with different phenotypes reported. Whether, when and how they generate memory cells are still poorly understood. Here, through single-cell RNA-sequencing analysis of CXCR5+Bcl6+ Tfh cells generated under different conditions, we discovered, in addition to PD-1hi effector Tfh cells, a CD62L+PD1low subpopulation. CD62L-expressing Tfh cells developed independently from PD-1+ cells, and not in direct contact with B cells. More importantly, CD62L+ Tfh cells expressed memory- and stemness-associated genes; with more superior long-term survival, they readily generated PD-1hi cells in the recall response. Finally, KLF2 and IL7R, also highly expressed by CD62L+ Tfh cells, were required to regulate their development. Our work thus demonstrates a novel Tfh memory-like cell subpopulation, which may benefit our understanding on immune responses and diseases.
Project description:Tfh and B cells were cultured together with or without Tfr cells. After 4 days Tfh and B cells were sorted and prepared for 3' targeted RNA-seq.
Project description:Peanut-specific IgE is present with peanut sensitizations at day 1 an day 8, while is absent with peanut sensitizations at day 1 and day 3. Since TFH and TFR cells are import in regulating antibody response in germinal center, we would like to know the different in TFH and TFR cells between D1D3 and D1D8 peanut sensitizations.
Project description:By using RNA-sequencing assay on sorted Sostdc1-EGFP- Tfh, Sostdc1+ Tfh and Non-Tfh cells and single cell RNA-seq assay on sorted CD4+CD44+T cells from Sostdc1-EGFP reporter mice, support the conclusion that Sostdc1+ Tfh cells are a distinct subpopulation of Tfh cells.After performing the RNA-seq assessment and ATAC-seq on Tfr and Treg cells from WT and Sostdc1 KO mice,demonstrated that Sostdc1 ablation predominantly augmented β-catenin-controlled transcriptome, which in turn resulted in Tfr cell failure.
Project description:Transcriptome analyses were done comparing gene regulation of TFH and TFR cells isolated from Peyer’s Patches (PP) and immunized peripheral lymph nodes (pLN) revealing many regulatory patterns common to all follicular cells. However, in contrast to TFH cells, the kinetic but also the extent of regulation regarding many genes was attenuated in pLN TFR cells when compared to those of PP. Additionally, PP but not pLN TFR cells were largely unresponsive to IL2 and expressed Il4 as well as Il21. Together with fundamental differences in gene expression that were found between cells of both compartments this emphasizes specific adaptations of follicular T cell functions to their micro-milieu.
Project description:Transcriptome analyses were done comparing gene regulation of TFH and TFR cells isolated from Peyer’s Patches (PP) and immunized peripheral lymph nodes (pLN) revealing many regulatory patterns common to all follicular cells. However, in contrast to TFH cells, the kinetic but also the extent of regulation regarding many genes was attenuated in pLN TFR cells when compared to those of PP. Additionally, PP but not pLN TFR cells were largely unresponsive to IL2 and expressed Il4 as well as Il21. Together with fundamental differences in gene expression that were found between cells of both compartments this emphasizes specific adaptations of follicular T cell functions to their micro-milieu.