Murine ?? T Cells Render B Cells Refractory to Commitment of IgA Isotype Switching.

ABSTRACT: ?? T cells are abundant in the gut mucosa and play an important role in adaptive immunity as well as innate immunity. Although ?? T cells are supposed to be associated with the enhancement of Ab production, the status of ?? T cells, particularly in the synthesis of IgA isotype, remains unclear. We compared Ig expression in T cell receptor delta chain deficient (TCR?-/-) mice with wild-type mice. The amount of IgA in fecal pellets was substantially elevated in TCR?-/- mice. This was paralleled by an increase in surface IgA expression and total IgA production by Peyer's patches (PPs) and mesenteric lymph node (MLN) cells. Likewise, the TCR?-/- mice produced much higher levels of serum IgA isotype. Here, surface IgA expression and number of IgA secreting cells were also elevated in the culture of spleen and bone marrow (BM) B cells. Germ-line ? transcript, an indicator of IgA class switch recombination, higher in PP and MLN B cells from TCR?-/- mice, while it was not seen in inactivated B cells. Nevertheless, the frequency of IgA+ B cells was much higher in the spleen from TCR?-/- mice. These results suggest that ?? T cells control the early phase of B cells, in order to prevent unnecessary IgA isotype switching. Furthermore, this regulatory role of ?? T cells had lasting effects on the long-lived IgA-producing plasma cells in the BM.

SUBMITTER: Han HJ 

PROVIDER: S-EPMC6117511 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature