Interaction of CD5 and CD72 is involved in regulatory T and B cell homeostasis

Abstract

Regulatory IL-10-producing CD1d(high)CD5(+)CD19(+) B cells and CD4(+)CD25(+)Foxp3(+) T cells have been found to modulate immune responses in autoimmunity, infection, and cancer, but the interaction between these two cell subsets remains unclear. Through cell culture and flow cytometry (FACS), we analyzed the interaction of regulatory T cells (Tregs) and regulatory B cells (Bregs). A neutralizing antibody was used to determine the role of CD5 and CD72 in maintaining regulatory T and B cell homeostasis. We found that CD19(+)CD5(+)CD1d(hi) Bregs induced expansion of CD4(+)Foxp3(+) Tregs, and CD4(+)CD25(+) Tregs also induced expansion of IL-10-expressing Bregs. Once CD72 or CD5 was blocked, both IL-10-expressing Bregs and CD4(+)Foxp3(+)Tregs were reduced in the different cultures. Finally, FACS analysis demonstrated that Foxp3(+)CD4(+)Treg cells were reduced in CD19(Cre) mice defective of CD5 on the surface of B cells. The study suggests that the interaction of CD5 and CD72 plays a critical role in maintaining regulatory T and B cell homeostasis.

IL-10-Producing B Cells Regulate T Helper Cell Immune Responses during 1,3-β-Glucan-Induced Lung Inflammation

“…In the current study, anti-CD22 treatment led to higher level of Th17 response. The negative correlation between B10 and Th17 response was also reported (46). Others believed that B10 could inhibit Th17 response only when Th1 response was absent (47).…”

Lipid mediator lipoxin A4 inhibits tumor growth by targeting IL-10-producing regulatory B (Breg) cells

“…Notably, Breg cells may also use IL-10-independent means to induce Treg cell development. CD5 and CD72 molecules on the surface of IL-10-producing Breg cells have been reported to be involved in the induction of Treg cells [43].…”

Positive and negative functions of B lymphocytes in tumors

“…No difference is observed when co-cultured with non-Breg cells (4.22 ± 0.28 vs. 4.44 ± 0.23, p > 0.05) [52]. Conversely, CD4 + CD25 + Tregs can also induce the expansion of B10 cells [81], thus facilitating a vital interaction between the two cells. A unique Bregs subset called tumor-evoked Bregs (tBregs) is discovered in breast cancer.…”