Nucleotide-free diet impairs T-helper cell functions in antibody production in response to T-dependent antigens in normal C57B1/6 mice.

We have previously shown that polynucleotides enhance in vitro antibody production in response to T-dependent antigens. This study examines the importance of dietary nucleotides on in vivo antibody production in response to antigen stimuli. C57Bl/6 mice fed a nucleotide-free diet for more than 3 wk demonstrated significantly lower antibody production to T-dependent antigens both in vivo and in vitro compared with control mice fed a nonpurified diet. Numbers of immunoglobulin M and G secreting cells in the spleen were also lower in mice fed a nucleotide-free diet after the challenge of T-dependent antigens compared to the controls. Responses to T-independent antigens remained intact in mice fed a nucleotide-free diet. T-helper cells from mice fed a nucleotide-free diet were less capable of inducing T-dependent antibody production in vitro compared with those from mice fed a nonpurified diet. Intraperitoneal injection of a mononucleotide-nucleoside mixture restored T-helper cell functions and T-dependent antibody production in mice fed a nucleotide-free diet. These results may indicate the importance of dietary nucleotides in maintaining optimal T-helper cell functions for humoral immune responses in response to T-dependent antigens.