Mouse strain and sex differences in the number and distribution of salivary gland IgA plasma cells.

OBJECTIVE

Salivary immunoglobulin A (IgA) produced by IgA plasma cells (PCs) in the salivary glands (SGs) plays a key role in maintaining immune homeostasis in the oral mucosa. We investigated differences by sex and mouse strain in salivary IgA concentration and IgA PC distribution among the major SGs.

METHODS

Pilocarpine-induced saliva was collected from male and female BALB/c and C57BL/6 mice, and salivary IgA concentrations were assessed using ELISA. Cells were isolated from the parotid, submandibular, and sublingual glands and analyzed using flow cytometry to quantify IgA PCs.

RESULTS

Salivary IgA concentrations were higher in BALB/c mice than in C57BL/6 mice, with no sex-related differences. Total numbers of IgA PCs in the three major SGs were consistently higher in BALB/c mice than in C57BL/6 mice, with no sex differences. In both strains, male mice exhibited parotid gland-dominant distribution of IgA PCs, whereas female mice exhibited submandibular/sublingual gland-dominant distribution.

CONCLUSIONS

The present results reveal distinct strain and sex differences in salivary IgA concentrations and in numbers and distribution of SG IgA PCs.