Calorie restriction modulates Th-1 and Th-2 cytokine-induced immunoglobulin secretion in young and old C57BL/6 cultured submandibular glands

Immunoglobulin production by the salivary gland plays an important role in oral and upper respiratory tract immunity. Age and/or disease may compromis e salivary gland function. In order to gain insight into the role of calori e restriction (CR) on immunoglobulin (Ig) production, we determined the eff ect of ad libitum (AL) feeding and CR in young (3 months) and old (18-24 mo nths) C57BL/6 mouse submandibular glands (SM). The SM tissues were fragment ed and cultured in the absence (control) or presence of either Th-1 cytokin es, such as interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), or Th-2 cytokines, e.g. IL-4 and IL-5, for seven days. Culture supernatants were th en analyzed for immunoglobulin A (IgA) IgM, and IgG(2a) levels by ELISA. Ag ing increased basal (control) IgA and IgM production by 3.1- and 3.7-fold r espectively, in AL mice. CR prevented the age-dependent rise of both IgA an d IgM, maintaining levels equal to those of young AL mice. Interestingly, a ge resulted in a decrease of Th-1 cytokine-induced IgA and IgM, and increas ed IgG(2a) secretion in AL mice, while Th-2 cytokines did not appear to hav e an age effect. In general, CR suppressed Ig production induced by both Th -1 and Th2 cytokines in young mice. In contrast, CR in old mice resulted in enhanced IgA and IgM production to levels similar to those in their young counterparts, while IgG(2a) was predominantly suppressed by Th-1 and not Th -2 cytokines. The data presented herein show, for the first time, the abili ty of CR to offset age-induced changes in submandibular gland Ig production , which may play a role in maintaining mucosal immune function, including p roper oral health. (Aging Clin. Exp. Res. 11: 383-389, 1999) (C)1999, Editr ice Kurtis.