The influence of immunization of female mice with F9 teratocarcinoma cells on their reproductive performance

Immunization of female 129/TER SV mice with heavily irradiated teratocarcinoma cells expressing F9 antigen significantly interfered with successful pregnancy. Histologic examinations of the uteri and ovaries of immunized and control females revealed normal corpora lutea and pseudopregnant uteri. These features indicate that the immunized females ovulated following the matings and that the mice were endocrinologically intact. No implantation sites were ever observed in the immunized females, suggesting that local anti-F9 antibody in the female reproductive tract interferes with conception or gestation prior to implantation. This alteration could involve sperm function, sperm-egg interactions, or events essential for postfertilization cleavage of the fertilized ovum or the implantation process itself. Since some females developed tumor during the immunization period, we were concerned that infertility in immunized females was due to microfoci of tumor with endocrine or paraendocrine activity. The one female with metastatic tumor who established a pregnancy and the lack of identifiable tumor in histologic specimens of mated females not establishing successful pregnancies make this possibility unlikely. Studies are in progress to determine where in the reproductive chain of events anti-F9 antibody interferes with successful pregnancy.