Characterization of anti-channel catfish MHC class IIβ monoclonal antibodies

This study characterizes four monoclonal antibodies (mAb) developed against the major histocompatibility complex (MHC) class II β chain of the channel catfish, Ictalurus punctatus. Immunoprecipitations using catfish clonal B cells revealed that each of these mAbs immunoselected proteins of approximately 32 and 36 kD, which are of the appropriate sizes for MHC class II α and β chains, respectively. Cell distribution studies using a fluorescence-activated cell sorter (FACS) combined with RT-PCR analyses demonstrated that MHC class II β is expressed at a high density on catfish clonal macrophage, B and T cell lines, on alloantigen stimulated leukocytes, and on lipopolysaccharide-induced B-cell blasts. Collectively, these results demonstrate the potential importance of these antibodies as reagents in future studies dealing with the functional role of MHC class II molecules in immune recognition of self from non-self.