Transfection of genes encoding lymphocyte differentiation antigens: applications in veterinary immunology

The work conducted so far in this laboratory has demonstrated the application of the use of genes encoding lymphocyte differentiation molecules, in the isolation of homologous genes from other mammalian species, by the technique of cross-species DNA hybridization. The studies have also highlighted the use of transfection as a means of obtaining expression of genes, either from total genomic DNA or cloned in plasmids, which encode lymphocyte antigens. Preliminary work presented in this paper demonstrates the application of these technologies in the isolation and expression of genes for lymphocyte antigens from species in which the gene products have not been fully defined. We favour this approach because it may allow isolation and definition of important immunological molecules independently of the existence of specific antibodies. It therefore seems the most direct way to avoid the frustrating randomness in production of anti lymphocyte subset-specific monoclonal antibodies, and to shorten the time and effort needed to define the specificities of such reagents. Furthermore, the cDNA clones isolated from alternate species (in this case the bovine) have a use in classical immunological studies apart from the application of antibodies made to their products in veterinary immunology. That is, comparisons of the DNA sequences of lymphocyte differentiation antigens from different species provide much important information about structural or functional elements of evolutionarily conserved proteins involved in generation of immune responses.