Pattern of CD14, CD16, CD163 and CD172a expression on water buffalo (Bubalus bubalis) leukocytes

•The study expands monoclonal antibodies available to define and study buffalo monocytes.•Cross-reactive monoclonal antibodies that recognize buffalo CD16 and CD163 orthologues were identified.•Buffalo CD14+ monocytes co-express CD16, CD163 and CD172a.•Buffalo granulocytes co-express CD16 and CD172a. Previous studies on the immune system of water buffalo (Bubalus bubalis) using cross-reactive monoclonal antibodies (mAbs) revealed significant similarities and differences to the bovine immune system. Herein, we extend these studies and document the pattern of expression of CD14, CD16, CD163 and CD172a on buffalo leukocytes using a set of cross-reactive mAbs that are known to recognize conserved epitopes within orthologous molecules in cattle, sheep and goats. Buffalo leukocytes were isolated and subjected to mAb labelling for flow cytometry. Single color flow cytometry confirmed mAbs recognition of buffalo orthologues of CD14, CD16, CD163 and CD172a, and revealed consistent patterns of expression similar to that reported in other ruminants. Multicolor flow cytometry revealed that buffalo CD14+ monocytes uniquely co-express CD16, CD163 and CD172a, whereas buffalo granulocytes co-express CD16 and CD172a. This study expands mAbs available to define and study the buffalo monocytes, and also extends information available on the unique features of the buffalo immune system.