Project description:We set up to characterize the global transcriptome of splenic follicular (FO) B cells from control wild type (Wt) and Igha-deficient (IgAKO) mice with the aim of gaining new insights into how translocated gut antigens may impair IgG production to vaccines in the absence of IgA. Splenic Marginal zone (MZ) B cells were also included in this study, as IgA deficiency impaired IgG responses to T-independent immunogens as well.
2024-01-01 | GSE173361 | GEO
Project description:Spink4 modulates gut microbiota to interfere IgA production
Project description:Immunoglobulin A (IgA)-producing plasma cells derived from conventional B cells in the gut play an important role in maintaining the homeostasis of gut flora. Both T cell-dependent and T cell-independent IgA class switching occurs in the lymphoid structures in the gut, whose formation depends on lymphoid tissue inducers (LTis), a subset of innate lymphoid cells (ILCs). However, our knowledge on the functions of ILCs, the innate counter parts of CD4 T helper cells, in promoting IgA production is still limited. By cell adoptive transfer and utilizing a unique mouse strain, we demonstrated that the generation of IgA-producing plasma cells from B cells in the gut occurred efficiently in the absence of both T cells and ILCs and without engaging TGFβ signaling. Nevertheless, B cell recruitment and/or retention in the gut required NKp46-CCR6+ LTis. Therefore, while ILCs contribute to the accumulation of B cells in the gut through inducing lymphoid structure formation, they are not essential for the T cell-independent generation of IgA-producing plasma cells.
Project description:IgA+ Plasma Cells were sort-purified from the small intestinal lamina prorpia of C57BL/6 mice at four Zeitgeber time points (ZT0, 6, 12 and 18). RNA extracted from these samples was subjected to bulk RNA seq to identify time of day differences in IgA+ PC gene expression.
Project description:To compare gene expression between CD11b+ IgA and CD11b- IgA cells in the small intestine, each cell population was isolated from the murine small intestine. Similar experiment with different sample was performed as described in Gene expression on CD11b+ IgA and CD11b- IgA cells in the small intestine #02
Project description:Krüppel-like factor 2 (KLF2) is a potent regulator of lymphocyte differentiation, activation and migration. However, its functional role in adaptive and humoral immunity remains elusive. Therefore, by using mice with a B cell-specific deletion of KLF2, we investigated plasma cell differentiation and antibody responses. We revealed that the deletion of KLF2 resulted in perturbed IgA plasma cell compartmentalization, characterized by the absence of IgA plasma cells in the bone marrow, their reductions in the spleen, the blood and the lamina propria of the colon and the small intestine, concomitant with their accumulation and retention in mesenteric lymph nodes and Peyer’s patches. Most intriguingly, secretory IgA in the intestinal lumen was almost absent, dimeric serum IgA was drastically reduced and antigen-specific IgA responses to soluble Salmonella flagellin were blunted in KLF2-deficient mice. Perturbance of IgA plasma cell localization was caused by deregulation of CCR9, Integrin chains αM, α4, β7, and sphingosine-1-phosphate receptors. Hence, KLF2 not only orchestrates the localization of IgA plasma cells by fine-tuning chemokine receptors and adhesion molecules but also controls IgA responses to Salmonella flagellin.
Project description:Gut resident IL10+CX3CR1hi macrophages drive development of mucosal tertiary lymphoid structures that serve as ectopic site of the IgA response to enteric infection.