Conclusion
Our data suggest that CPLX2 inhibits spontaneous secretion of IgM and IgG1 from splenic ASCs. This study provides new insight into the mechanism of antibody secretion of ASCs.
Methods
We examined the expression of CPLXs and SNAREs in lymphocytes. To study the effect of CPLXs on the immune system in vivo, we analyzed the immune phenotype of CPLX2 KO mice. Furthermore, antibodies secretion from the peritoneal cavity, spleen, and bone marrow cells of wild-type (WT) and CPLX2 KO mice were determined.
Results
CPLX2 was detected in B cells but not in T cells, while other CPLXs and SNAREs were expressed at a similar level in both B and T cells. To clarify the function of CPLX2 in B lymphocytes, serum concentrations of immunoglobulin G (IgG), IgA, IgM, and IgE were measured in WT and CPLX2 KO mice using enzyme-linked immunosorbent assay. The level of IgM, which mainly consists of natural antibodies, was higher in KO mice than that in WT mice, while the levels of other antibodies were similar in both types of mice. Additionally, we found that spontaneous secretion of IgM and IgG1 was enhanced from the splenic antibody-secreting cells (ASCs) of CPLX2 KO mice.