INTERSEX DIFFERENCE IN PRODUCTION OF ALLOANTIBODIES AND GROWTH OF TUMOR ALLOGRAFTS IN MICE

Abstract

The comparisons of immune responses to tumor allografts in male and female mice showed intersex differences. Production of humoral antibodies is, in general, higher in females. Since the time course of titers differs for hemagglutinating and cytotoxic antibodies as well as with the sex, the titer of the same antibody may be higher in males at certain time intervals when the peak is delayed and the production in females is already declining. In recipients specifically presensitized with spleen extract as well as in controls, the growth of allogeneic tumor (SaI) exhibits quantitative intersex differences being reduced in females. In the initial phase of growth, following the spleen extract, the facilitation (enhancement) of the tumor allograft is apparent only in males, whereas in females it is delayed. The facilitating effect of antibodies passively transferred from males or females corresponds mainly to the sex and strain of the recipient, only rarely to the sex of the producer. In the CBA strain mice, females are more resistant to the growth of SaI and also mortality from the primary tumor is lower in females, but the frequency of metastases in females is higher. In the IC strain, where the sex effect on tumor growth is particularly pronounced, the consequences of castration are concordant with the inferred hormonal control of the allograft response. In males, the relatively high percentage of lethal spontaneous takes (60%) is reduced following castration (to 13%), whereas the opposite trend is observed in females, namely an increase from 0% in sham-operated controls to 23% in the castrated group.