Monoclonal antibodies against leukocytes in the beluga whale, Delphinapterus leucas

抄録

To better understand cetacean immunology, it is important to develop markers that identify specific leukocyte populations. We created a monoclonal antibody (mAb) library against leukocytes of the beluga whale (Delphinapterus leucas), and established five hybridoma clones that produce mAbs. Three of these mAbs (ID: BW-3C3, BW-2G4, and BW-2G6) react with mononuclear leukocytes including lymphocytes and monocytes. mAb BW-3C3 react to a fraction of the lymphocytes. The mAb-positive cells were identical to cells that also stained with polyclonal anti-whale IgM antibodies, indicating that the mAb BW-3C3 specifically reacts to B lymphocytes. mAb BW-2G4 specifically binds to monocytes that possess a reniformed nucleus. mAb BW-2G6 was found to bind to heterogeneous lymphocytes, namely, anti-whale IgM antibody-positive and -negative lymphocyte populations. This indicates that this mAb reacts with B and non-B lymphocyte fractions. The other two mAbs (ID: BW-4B10 and BW-4G12) react with polymorphonuclear granulocytes. Double staining with Giemsa-eosin showed that mAb BW-4B10 and mAb BW-4G12 specifically identify neutrophils and eosinophils, respectively. This panel of mAbs will be a useful tool for classifying leukocytes and for determining their localization in different tissues, which in turn would contribute to our understanding of cetacean immunology and allow evaluation of leukocyte function in infectious diseases.