Antitumor antibodies and immunoglobulin class and subclass levels in Corynebacterium parvum-treated mice.

Changes in immunoglobulin class and subclass levels and the development of antitumor antibodies were assessed in normal and tumor-bearing mice challenged with Corynebacterium parvum. C. parvum administration resulted in a marked increase in certain immunoglobulin levels, especially Ig G2b, and in the development of antibodies reacting with syngeneic and allogeneic tumor cells. The serologic changes induced by C. parvum were dependent on the dose and route of administration; preliminary studies suggested that they may have been largly independent of T-cell function. These changes were suppressed by the administration of gold salts, which also inhibited the antitumor effect of C. parvum.