Allospecific monoclonal antibodies recognizing rat class I and class II histocompatibility antigens

Rat-mouse hybridomas have been developed producing monoclonal antibodies which recognize rat major histocompatibility complex specificities. Splenic lymphocytes from a LEW (RT1l) rat alloimmunized against ACI (Rt1a) splenocytes were used for hybridoma production. The six clones presented demonstrate two patterns of alloreactivity against ACI tissues: clone 36.3 produces an antibody which agglutinates ACI RBCs and binds to ACI splenic lymphocytes and RBCs. Five clones, 65.6, 79.7,1, 79.7.5, 155.3.1, and 189.3.5, from four independent wells produce monoclonal antibodies which bind to ACI splenic lymphocytes but not RBCs. Screening of these six monoclonal antibodies against a reference panel of RBCs and lymphocytes from 15 standard, congenic, and recombinant rat strains indicated that the monoclonal antibody 36.3 detects a RTI.Aa product ( a rat major histocompatibility complex (MHC) Class I antigen) and that 65.6, 79.7.1, 79.7.5, 155.3.1, and 189.3.5 are monoclonal antibodies which recognize a RT1.Ba private specificity (Class II or Ia antigens). These reagents are unique as they are rat monoclonal alloantibodies recognizing private Ia specificities of the rat MHC.