Transplacental tumor-preventive effects of polyclonal antibodies generatedagainst the soluble 53 kDa antigen on mammary tumorigenesis in offspring

This study was designed to determine whether immunizing females with polycl onal antibodies generated against the soluble 53 kDa tumor-associated antig en (s53 TAA) has a tumor-preventive effect on their progeny and whether thi s effect is manifested in some biochemical characteristics. Rat females wer e immunized before mating with anti-s53 Ige (50 mu g/rat in Freund's comple te and incomplete adjuvant, three times during a month) and their 5-week-ol d offspring was exposed to the carcinogen (dimethylbenz(a)antracene, 10 mg/ rat). Results of these experiments were studied 3 months later. Vaccination of mothers decreased the tumorigenic effects of DMBA on their offspring. B lood levels of soluble TAA were analyzed in offspring of different groups. Two TAA were isolated from the blood, with molecular masses of 63 and 53 kD a. Their concentrations differed in offspring obtained from different mater nal groups. Vaccination itself resulted in a marked increase in the blood l evels of TAA, not only in the mothers but also in their offspring, however, this increase was not significant in tumor-bearing animals. In offspring f rom non-vaccinated mothers, tumorigenesis resulted in high overexpression o f s53. In offspring from vaccinated mothers, a high blood level of s53 was shown even in tumor-free animals, probably due to maternal vaccination. We conclude that maternal vaccination before pregnancy increases immunoactivit y in offspring and can reduce risk of tumors in those progeny.