Preparation and characterization of murine monoclonal antibodies to swine lymphocyte antigens

A panel of monoclonal antibodies (mAb) was developed by the fusion of Sp2/0 myeloma cells and spleen cells from mice immunized with peripheral blood mononuclear cells (PMNC) or T cells from NIH swine leucocyte antigen (SLA) inbred miniature swine. Twenty stable hybridoma clones were isolated that secreted mAb that reacted with swine PMNC, as determined by an enzyme-linked immunosorbent assay (ELISA). The binding profile to swine PMNC and the ability to fix complement of these mAb were investigated by flow cytometric analyses. The molecular weights of the antigens recognized by six of the mAb were determined by immunoprecipitation of 125I surface-labelled PMNC, followed by SDS-PAGE under reducing conditions. The most interesting mAb, 7-34-1 (IgG2a), precipitated a putative MHC class I molecule composed of a 50,000 MW heavy chain and a 12,000 MW light chain (beta 2m). This is the third SLA class I-reactive monoclonal antibody to be described for swine. Properties of the mAb described in this paper, mAb 7-34-1, are different from the two other SLA class I-specific mAb that have been described elsewhere in the literature (mAb 74-11-10 and mAb PT85). Monoclonal antibody 7-34-1 recognized class I antigens of SLA haplotypes a, c and d in an equivalent manner. This mAb should be especially useful as a general anti-SLA class I reagent for experiments on NIH miniature swine.