Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 12, 1997
Publication Date: N/A
Interpretive Summary: The Second International Swine CD Workshop was successful in identifying a whole panel of new anti-CD3 monoclonal antibodies (mAbs), an important CD antigen that is expressed in all T-cells, subset for which previously no mAb had been identified. Five anti-CD3 workshop mAb were reactive with cloned porcine CD3 epsilon chain that had been expressed on transfected COS cells by British scientists, thus, these 5 mAb were assigned as reactive with epitopes of porcine CD3 epsilon chain and were designated as reactive with epitopes CD3a or CD3b based on reciprocal binding inhibition studies. All 3 CD3a reactive mAb caused proliferation of blood lymphocytes in the presence of phorbol myristic acetate (PMA). As a result of this workshop, 6 anti-CD3 mAb have now been defined in swine, three of which react with the CD3a epitope that when bound will cause T cell proliferation in the presence of PMA. Production of mAb which recognize the important pan-T cell determinant, the CD3 molecule, will enable scientists to clearly differentiate swine T cells and to assess fully functions of this important subpopulation as they define swine immune cell interactions. The international workshop enables scientists worldwide to independently verify the reactivity of panels of mAb and thus to precisely identify important new reagents to aid analyses of swine immune responses particularly those involved in controlling disease and vaccine responses.
Among the 57 monoclonal antibodies analyzed within the T-cell group from the Second Swine CD Workshop, 6 mAb fell within clusters T10 and T11 (No. 088, STH164; No. 148, FY1A3; No. 149, FY2C1; No. 150, FY1H2; No. 151, FY2A11; No. 169, BB23-8E6). The mAb within these two groups gave a similar appearance on flow cytometry and stained all peripheral blood T-cells as defined by wCD4 and w CD8 staining. All six mAb precipitated a 24 kDa protein. On the basis of inhibition analyses performed as part of the workshop and from published data, the mAb define at least 3 epitope groups. There is only minimal stimulation of resting peripheral lymphocytes, but four of the mAb produce strong stimulation in the presence of PMA. With the exception of STH164, all have been shown to react with CD3E-transfected COS cells. The new mAb therefore react with 3 epitopes on porcine CD3E designated CD3a (BB23-8E6, FY2A11), CD3b (FY1A3, FY2C1), and CD3c (FY1H2). mAb STH164 appears to be reactive with another epitope, however, since its reactivity with CD3 has not been confirmed it is designated as wCD3.