1,25-dihydroxyvitamin D3 and 1,24-dihydroxyvitamin D3 suppress invitro antibody response to T cell-dependent antigen

Summary 1,25-Dihydroxyvitamin D 3 and 1,24-dihydroxyvitamin D 3 suppressed an antibody response to sheep red blood cells (SRBC, T cell-dependent antigen) by murine splenocytes, in concentrations ranging from 10 −10 –10 −7 M. These suppressive effects were markedly abrogated when T cell-depleted lymphocytes were cultured in the presence of a supernatant of concanavalin A-stimulated spleen cells. On the contrary, neither of them suppressed antibody response to trinitrophenyl-lipopolysaccharide (T cell-independent antigen). These results suggest that the suppressive effect of active vitamin D 3 on anti-SRBC response was mediated by the inhibition of T cells.