Immunosuppression by Leukemia Viruses

Abstract

Abstract Specific antibody-forming cells contained in spleen cell suspensions from normal immunized donor mice were adoptively transferred to both normal and Friend disease virus-infected recipient mice. There was little or no suppression with time in the number of the transferred antibody-forming cells in infected animals as compared to controls, under conditions in which there was a marked suppression of antibody-forming cells in mice directly challenged with antigen. A study of the cytokinetics of the antibody plaque response in infected and control recipients indicated that the largest number of plaque-forming cells (PFC) could be determined in recipient spleens between 1 and 3 days after cell transfer. However, there were significant numbers of PFC in recipient spleens 6 and 9 days after transfer. Infection of recipient mice simultaneously or 3 days before cell transfer did not result in an inhibition of the expected number of PFC. In most instances there was a 60% to 70% increase in the number of plaque-forming cells in spleens of mice infected the same day as cell transfer during the subsequent 3 days. Recipient mice infected 8 days before cell transfer generally had 25% to 40% fewer antibody-forming cells in their spleens on the peak day after cell transfer, as compared to control recipients. However, there were almost normal numbers of antibody- forming cells 6 to 9 days after transfer, as compared to controls and the other groups of infected recipients. The results of these experiments have been interpreted as indicating that the immunosuppressive effects of a murine leukemia virus such as Friend disease virus do not occur at the level of mature antibody-forming cells.