Abstract
Infection of mice with the lactic dehydrogenase virus (LDV) resulted in an elevated level of gamma-globulin. Histologic examination of the spleen and lymph nodes revealed that the number of germinal centers was greatly increased. Immunization with human gamma-globulin showed that the capacity of the virus-infected animal to produce anti-human gamma-globulin was greatly enhanced and that the virus acted as an adjuvant. From these experiments it is concluded that a virus infection (LDV) can affect the immunologic response of the host to a heterologous antigen.