Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/1/2008
Publication Date: 11/1/2008
Citation: Moulana, M., Evenhuis, J., Kountikov, E.I., Wilson, M., Bengten, E., Miller, N.W., Mcconnell, T. 2008. Characterization of anti-channel catfish MHC class II monoclonal antibodies. Veterinary Immunology and Immunopathology. 126:120-130. Interpretive Summary: The lack of viable tools or reagents is a major obstacle and area of interest for defining fish immune function. In an effort to resolve this problem four antibodies specific for the major histocompatibility complex class II beta (MHCIIb) molecule of the channel catfish were tested against several immune related cell lines and tissues. These antibodies were also compared to previously characterized catfish specific antibodies, by a fluorescence activated cell sorter (FACS), for cell surface staining on the peripheral blood leukocytes (white blood cells) and kidney cells of the channel catfish. These four antibodies showed that a high amount of MHCIIb was expressed on the surface of B cells (antibody producing cells). This finding corroborate the previous finding that fish B cells are important cells in the engulfing and presentation of pathogen molecules to induce a proper immune response. Also, these antibodies were able to recognize and bind to the surface of a variety of white blood cell types suggesting that the MHCIIb is an important molecule in self versus non-self recognition. This paper illustrates the importance of these antibodies as useful tools for study of the immune system in the channel catfish.
Technical Abstract: This study characterizes four monoclonal antibodies (mAb) developed against the major histocompatibility complex (MHC) class II beta 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 a and b chains, respectively. Cell distribution studies using a fluorescence-activated cell sorter (FACS) combined with RT-PCR analyses demonstrated that MHC class II beta is expressed at a high density on catfish B and T clonal cell lines, on alloantigen stimulated leukocytes, and on lipopolysaccharide-induced B-cell blasts. The finding that B cells expressed high levels of MHC class II indicate that catfish B cells can act as antigen presenting cells and may be related to the recent finding that teleost B cells are potent and proficient phagocytic cells. 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.