EFFECT OF CYCLOPHOSPHAMIDE ON THE IMMUNE-RESPONSE OF BALB-C MICE BEARING AN IMMUNOGLOBULIN-M PLASMACYTOMA (TEPC-183)

  • 1 January 1981
    • journal article
    • research article
    • Vol. 41  (3) , 801-807
Abstract
Mice bearing TEPC-183, an IgM (k)-secreting plasmacytoma, exhibit severe suppression of their immune responses. Since chemotherapy with cyclophosphamide (CY) is used in the treatment of myeloma, its effect on the immune response was studied. CY was tested at different doses to determine whether a tumor-lytic dose could be established which would minimally impair the immune response. CY was injected at different time intervals in respect to antigen administration; its short- and long-term effects on the immune response were determined. CY (1 mg) suppressed the 6-day primary immune response to the type 3 pneumococcal polysaccharide SSS-lll, and even a secondary response 30 days later. A dose of 3 mg CY was required to suppress the primary and the secondary immune response elicited by 2, 4-dinitrophenyl-hemocyanin. One injection of 1 mg CY per mouse resulted in complete regression of all tumors. Splenectomy did not aid in the recovery of the immune response to SSS-lll but accentuated the impairment. The time of CY administration played a crucial role in affecting the immune response. When CY was administered simultaneously with or 2 days after antigen injection, it was totally suppressive; the immune response was enhanced when CY was given 4 days prior to antigen injection. Minimal effects were observed when CY was given at other time intervals.