Sensitivity to androgen. A possible factor in sex differences in the immune response.

In strains of mice with high or low sensitivity to androgen, previous studies demonstrated that sex differences in the levels of certain Igs occurred only in the high androgen responder (HAR) strain, but not in the low androgen responder (LAR) strain. HAR C57L/J males, whether intact or castrated, had lower levels of IgM and IgG2 than C57L/J females, and lower levels of IgM and IgG2 than LAR A/J mice (Cohn & Hamilton, 1976). The current study indicates that the pattern of low immune response characteristic of HAR males in non-specific responses also occurs in response to three different antigens and is evident in another HAR strain, the RF/J. Results show that in response to type 3 pneumococcal polysaccharide (SIII), HAR C57L/J males consistently produced lower levels of antibody than C57L/J females, whereas LAR A/J males and females produced similar levels of anti-SIII. HAR C57L/J males also produced significantly lower levels of anti-SIII than LAR A/J males following restricted doses of SIII (50 ng). Altering the concentration of circulating testosterone in HAR C57L/J males had no effect on their anti-SIII responses. In assays of another pair of HAR and LAR strains, the RF/J and 129/J, HAR RF/Js had significantly lower anti-SIII responses than LAR 129/Js. In response to bovine serum albumin (BSA), HAR C57L/J mice showed sex differences in anti-BSA responses both 14 and 21 days after immunization, whereas HAR A/J mice showed sex differences on day 14 only, before peak responses developed. Of all mice assayed, however, HAR C57L/J males had the lowest levels of anti-BSA on both days. When strains differing in sensitivity to androgen and H-2 type were assayed for antibody to bovine gamma-globulin (B-IgG), RF/J females produced comparatively high antibody responses as expected for H-2 strains, but HAR RF/J males produced the lowest levels of antibody of all mice assayed. The results of these studies support and extend earlier observations of an apparent correlation in male mice between high sensitivity to androgen and poor immune responsiveness.