B lymphocytes

Vitamin A deficiency impairs the growth, activation and function of B lymphocytes. B lymphocytes have been shown to utilize a metabolite of retinol, 14-hydroxy-4,14-retro-retinol, instead of retinoic acid, as a mediator for growth (Buck et al., 1991). The effects of retinol and all-trans-retinoic acid on immunoglobulin synthesis by B lymphocytes have been examined in human cord-blood and adult peripheral-blood mononuclear cells (Israel et al., 1991; Wang and Ballow 1993; Wang et al., 1993; Ballow et al., 1996). A T-cell-dependent antigen was used to induce differentiation of sensitized human B lymphocytes into immunoglobulin-secreting cells, and all-trans-retinoic acid increased the synthesis of IgM and IgG by these cells. Highly purified T lymphocytes incubated with retinoic acid enhanced IgM synthesis by cord-blood B lymphocytes, suggesting that retinoic acid modulates T-cell help through cytokine production (Ballow et al., 1996).

0 0

Post a comment