[Humoral reactions in BALC/c mice with sarcomatous Moloney-induced tumor]. / Gumoral'nye reaktsii myshei BALB/c pri induktsii opukholi sarkomatoznym virusom Moloni.

In a progressive course of the blastomatous process induced by MSV-Moloney the antitumor antibodies level in the whole blood serum was practically unchanged, while the level of antibody-forming cells (AFC) in the spleen of these mice was considerably decreased as compared with that in the spleen of intact mice of the same age. If the tumor development was followed by its subsequent resorption, a biphase character of enhancement of the cytotoxic activity both of the whole serum and its fractions was noted. In the utmost developed tumor a reduced AFC level was observed, while in its resorption -- a gradual restoration of the AFC values up to the level characteristic of intact animals of the same age group.

Effect of influenza virus on the immune responsiveness of animals.

Infection of mice with A/Hong Kong/1/68 (H3N2) and A/PR8/34 (H0N1) influenza virus strains resulted in a significant inhibition of the formation of antibody-producing cells in response to administration of sheep erythrocytes and a reduced capacity of spleen cells to induce "graft-versus-host" reaction. The immunosuppression caused by influenza infection was observed for a long period of time post infection (3--6 months). The extent of inhibition of antibody production depended on the dose of virus, route of inoculation, the sequence of infection and immunization and the internal between them. Heat-inactivated virus exerted no immunosuppressive effect.