Cross-reactivity of a monoclonal antibody with bovine, equine, ovine, and porcine peripheral blood B lymphocytes.
Ficoll-thrombin purified suspensions of bovine, equine, ovine, and porcine peripheral blood lymphocytes were fractionated on nylon-wool columns. The percentages of surface immunoglobulin (SIg+)-bearing lymphocytes in the adherent (B-cell enriched) and nonadherent (T-cell enriched) fractions were determined for individual animals using fluorescein isothiocyanate conjugated species-specific anti-Ig sera. Subsequently, the human leukocyte antigen DR-specific monoclonal antibody, H4, was tested for its ability to recognize a cross-reactive antigen on the fractionated lymphocytes, using the microcytotoxicity technique. The H4 plus complement killed a percentage of lymphocytes equivalent to the percentage of SIg+ lymphocytes in the adherent and nonadherent fractions. In a parallel experiment, a 2 fluorochrome technique was used to visualize bovine lymphocytes that were SIg+ and H4+. Lymphocytes that were SIg+ also stained with ethidium bromide (orange fluorescence) after complement-mediated cytotoxicity. Seemingly, H4 recognizes an evolutionarily conserved major histocompatibility complex encoded class-II-like determinant on the B lymphocytes of cattle, horses, sheep, and swine.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002417:Cattle / Q000276:immunology*; D003429:Cross Reactions; D003601:Cytotoxicity Tests, Immunologic; D005455:Fluorescent Antibody Technique; D006736:Horses / Q000276:immunology*; D012756:Sheep / Q000276:immunology*; D013045:Species Specificity; D013552:Swine / Q000276:immunology*
D000911:Antibodies, Monoclonal