Transmission of BCG-associated tumor resistance from maternal to newborn guinea pigs.

Resistance to line-10 hepatocarcinoma was studied in the newborn offspring of inbred strain-2 Sewall Wright guinea pigs that had recovered from this tumor after prior administration of subcellular components of Mycobacterium bovis strain BCG. These mothers gave birth to 15 offspring, 53% of which resisted repeated challenges with this tumor. Offspring of mothers who had been given only BCG components were similarly tested. Complete protection was observed in 23.5% of 17 babies and attenuation of disease in many others. All control offspring from normal, untreated mothers succumbed to this tumor. Resistance was associated with delayed cutaneous hypersensitivity reactions to tumor and mycobacterial antigens.