Production and Characterization of Monoclonal-Antibodies Differentiating Subpopulations of Porcine B-Lymphocytes in Blood and Lymphoid-Tissues

Monoclonal antibodies (mAbs) against various subclasses of immunoglobulin molecules are important reagents for the characterization and differentiation of serum immunoglobulins (Ig) generated during immune responses. Furthermore, Ig-specific mAbs can be powerful tools for the detection of B lymphocytes in blood and lymphoid organs. Here we describe two mAbs generated in our laboratories, named 1G6 and 2E8, which react with distinct epitopes on porcine immunoglobulin molecules. MAb 1G6 recognizes an epitope of an immunoglobulin chain with apparent molecular mass of 25 Kd. This chain represents an immunoglobulin light chain and might be the porcine equivalent of the murine and human kappa chain. MAb 2E8 is directed against porcine IgM molecules, recognizing an epitope of the porcine mu chain. The use of these mAbs was shown to avoid some common disadvantages of anti-Ig polyclonal antisera, like the high background staining of cells and tissue culture sections in immunohistochemistry. Furthermore, the use of these mAbs in two-color flow cytometry (FCM) versus a polyclonal anti-porcine Ig antiserum enables distinct B-lymphocyte subpopulations in blood and lymphoid organs to be detected. Our mAbs seem therefore to represent important and powerful reagents to identify and characterize porcine Ig isotypes and surface-Ig positive porcine B lymphocytes; their discriminating power between distinct B lymphocyte subpopulations could prove useful in different fields of both applied fundamental immunological research