Immune competence of hereditarily asplenic mice

Abstract

Antibody formation and cellular immunity were studied in congenitally asplenic mice challenged with sheep erythrocytes (SE) and transplants of skin and spleen. Asplenic mice had a significantly lower antibody production than normal animals, albeit higher than splenectomized littermates in the primary and secondary immune responses. The serum levels of immunoglobulin (Ig) M of asplenic mice were deminished after a primary immunization and normal in the secondary response. Although the serum concentration of IgG2 was normal after a single antigenic stimulation, there was a reduction of IgG2 serum levels during the secondary response. The serum concentration of IgG1 was significantly higher in asplenic than normal mice. The number of 19S PFC was markedly reduced throughout the lymphopoietic system of asplenic mice which had a large number of 19S and 7S PFC in the blood stream, when compared to normal littermates, after a single antigen injection. During the secondary immune response there was a great improvement of the number of PFC in lymph nodes of normal and splenectomized mice but not in that of asplenic mice. The number of 7S PFC in other lymphoid tissues of asplenic mice was markedly diminished. Hereditarily asplenic mice had normal cellular immunity as indicated by normal rejection times of spleen and skin allografts. The results are consistent with the concept of decreased antibody production associated with asplenia and demonstrated the important function of the spleen during embryogenesis to achieve normal humoral immunity in adult life.