Adriamycin induced immunomodulation: dependence upon time of administration.

The immunomodulating capabilities of the anti-neoplastic agent, Adriamycin, were investigated. The day of Adriamycin administration to mice was varied from -15 to -1, day 0 being when mice were either immunized or sacrificed and their spleen cells sensitized in culture. Humoral and cellular immune responses against allogeneic or xenogeneic cellular antigens in mice and in culture, as well as phagocytic and ADCC activities were evaluated using spleen cell populations. The cellular responses and phagocytic activities were affected in a cyclical manner with time after Adriamycin's administration. Peaks of increased activity were seen subsequent to day -5 and day -11, administration and low activities following day -1, -3 and day -7, -9 administration. The humoral responses were not affected in a biphasic manner but single peaks of increased activity were seen which corresponded to the times of low cellular cytolytic and phagocytic activities. The ADCC was independent of time of Adriamycin administration. The significance of these findings to the design of therapeutic protocols is discussed.