Suppression of myeloma establishment in adult mice with anti-μ antiserum

Abstract

Uniform suppression of MOPC-104E tumor development was observed in adult BALB/c mice to which 0.4 ml of high titered anti-μ antiserum had been administered intraperitoneally or intravenously one day before subcutaneous tumor implantation. In contrast, when MOPC-104E cells were exposed to anti-μ antiserum in vitro for 10 min and subsequently injected into adult BALB/c mice, inhibition of tumor development was observed in only about half of the subject animals. Nude mice treated intraperitoneally with anti-μ antiserum were also uniformly refractory to MOPC-104E challenge. Anti-μ antiserum exhibited virtually no cytotoxicity against MOPC-104E cells in vitro. These observations suggest that neither complement-mediated cytotoxicity nor T cell-mediated immunity is likely to be the primary mechanism for anti-μ-mediated suppression of myeloma development in adult BALB/c mice. More plausible explanations for this type of suppression include macrophage arming, some type of antibody-dependent cell-mediated cytotoxicity, and/or opsonization.