Lymphocytic Choriomeningitis Infection in Neonataily Thymectomized Mice Bearing Diffusion Chambers Containing Thymus.

Normal, nonoperated Swiss mice which had been inoculated intracerebrally with lymphocytic choriomeningitis virus showed a 100-percent mortality within 8 days after virus challenge. Neonatally thymectomized mice, with or without empty intraperitoneal diffusion chambers, were protected from the lethal effects of the virus, with no animals dying within 14 days after inoculation. Cell-tight Millipore diffusion chambers containing newborn thymic tissue, implanted intraperitoneally into neonatally thymectomized mice, restored the susceptibility of 52 percent of these mice to the lethality of the virus infection. The percentage restoration with subcutaneous thymic grafting was similar. A humoral mechanism of action of the tissue in the chamber is proposed.