Cyclophosphamide (Cy)-facilitated adoptive immunotherapy of a Cy-resistant tumour. Evidence that Cy permits the expression of adoptive T-cell mediated immunity by removing suppressor T cells rather than by reducing tumour burden.
A cyclophosphamide (Cy)-resistant immunogenic tumour, the L5178Y lymphoma, was used to demonstrate that Cy-treatment of a host bearing this tumour enables passively transferred tumour-sensitized T cells to cause complete tumour regression without any need for Cy to cause a reduction in tumour burden. It was shown that whereas infusion of tumour-sensitized T cells from immune donors had very little effect on growth of the tumour, and whereas treatment with 150 mg/kg of Cy caused appreciable enhancement of tumour growth, combination therapy with Cy plus immune T cells caused complete tumour regression and resulted in long-term survival. Evidence that Cy treatment facilitated the expression of adoptive immunity against the L5178Y lymphoma by eliminating tumour-induced suppressor T cells consisted of the demonstration that tumour regression caused by combination treatment with Cy and immune T cells could be inhibited by infusing the recipient with Cy-sensitive, L3T4+ T cells from tumour-bearing but not from normal donors.
Awwad
M
M
Trudeau Institute, Inc., Saranac Lake, NY 12983.
North
R J
RJ
D000818:Animals; D003131:Combined Modality Therapy; D003520:Cyclophosphamide / Q000627:therapeutic use*; D007116:Immunization, Passive; D007940:Leukemia L5178 / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D007942:Leukemia, Experimental / Q000628:therapy*; D051379:Mice; D008815:Mice, Inbred Strains; D013601:T-Lymphocytes / Q000637:transplantation; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects*; D013997:Time Factors
D003520:Cyclophosphamide