Vitamin A depletion and repletion: Effects on antibody response to the capsular polysaccharide of Streptococcus pneumoniae, type III (SSS-III)

To determine the ability of young rats to produce antibody against pneumococcal polysaccharide (SSS-III), weanling rats were fed a semipurified diet containing no retinol (A-) or 4 μg retinol/g diet (A+). Splenic antibody response specific to SSS-III was 17% (p ≤ 0.05) of control for A- Sprague-Dawley rats; similarly, the response of retinol-depleted Lewis rats was 22% (p ≤ 0.05) of pair-fed controls. No kinetic differences were observed in the antibody response between A- and control Lewis rats. Retinol depletion more markedly reduced the antibody response of male than female rats despite equally low tissue retinol concentrations. For both strains, retinol repletion near the time of immunization normalized antibody production. When male Lewis rats were fed the A- diet longer, the antibody response of A- rats was only 3% of pair-fed controls; repletion again normalized antibody production. Thus, retinol supplementation near the time of immunization can restore the immune response in previously compromised A- rats.