Monoclonal antibodies to rat sarcomata. I. Immunization procedures and source of lymphoid cells for hybridoma production.

Hybridomas secreting monoclonal antibodies with specificity for Hooded rat fibrosarcomata have been obtained by fusion of the rat myeloma Y3 Ag 1.2.3. (Galfre, Milstein & Wright, 1979) with cells taken from spleens or lymph nodes of immunized syngeneic and allogeneic donors. Two of the monoclonal antibodies, both derived from he spleens of tumour bearers, showed specificity for individual tumours one for MC24 (M10/76) and the other for HSNTC (11/160). These two antibodies had a long half-life in the blood when injected intravenously showing that they had a low affinity for normal tissue antigens. Monoclonal antibodies exhibiting broad tumour specificity or extensive cross-reactivity with normal cells were secreted by many of the hybridomas derived from both syngeneic and allogeneic rats that had been hyperimmunized with tumour cells. These results are discussed in relation to the production of monoclonal anti-tumour antibodies for use in experimental therapy.