Abstract

The dromedary camel as a livestock species significantly impacts the economy of arid and semi-arid regions worldwide. The identification of cross-reactive antibodies against pivotal immune cell markers acts as a valuable method to investigate the immune system of camels. The aim of the present study was to identify new monoclonal antibodies that react with camel leukocyte subsets using flow cytometry and multicolor immunofluorescence. The expression patterns of the tested antibodies indicated cross-reactivity of the anti-bovine CD9 monoclonal antibody clones LT86A and Hl9a with different binding potential. Although all leukocyte subpopulations stained positively with the CD9 antibodies, monocytes showed the highest CD9 abundance, compared to lymphocytes and granulocytes. No cross-reactivity was identified for the tested monoclonal antibodies against equine CD8a (clone: ETC142BA1), mouse CD3 (clone: CD3-12), human CD3 (clone: T3/2/16A9), human CD206 (clone: MMR), and bovine granulocytes (clone: CH138A). The present study revealed that only camel monocytes showed positive staining with the anti-ovine CD5 mAb (clone ST1), which is in contrast to the human and murine systems. The present findings indicated low homogeneity between camels and other species in the antigenic structure of leukocyte antigens, highlighting the need to develop camel-specific mAbs against the main immune cell markers. © The Author(s) 2023. All Rights Reserved.