The Immunophenotype of Blood Mononuclear Cells in Three Age Groups of Dromedary Camels (Camelus dromedarius)

Age related changes in the immune system were described for different humoral and cellular immune components in man and animal. Studies on the development of the cellular immune system in camels are limited. Therefore, the present study compared the three age groups of camels regarding the immunophenotype of mononuclear cells in their blood. Thirty-four dromedary camels were divided, based on their age, into three groups (G) with camels in G1 aged 3 - 11 month, camels in G2 aged 2 - 5 years, and G3 camels aged 6 - 10 years. The immunophenotype of mononuclear cells was analysed by flow cytometry. The results revealed higher percentage of lymphocytes in G1 and G2 than G3, while lymphocyte absolute numbers were only higher in G1 than the other two groups. Within lymphocytes, the absolute numbers of WC1+ T cells and B cells were highest in G1 compared to the other two groups, while the absolute numbers of CD4+ T cells did not show significant differences between the groups. In addition, the reduced abundance of CD11ahigh and CD44high lymphocytes together with the reduced expression of CD9 on lymphocytes and MHC II on monocytes indicate the reduced maturity of the camel immune system during the first year of life. In conclusion, the present study identified significant age-related changes in the immunophenotype of mononuclear cells in camel blood. The changes are characterised by a decrease in the number of lymphocyte, gd T cells, and B cells. In addition, age was associated with an expansion in activated lymphocytes and monocytes in camel blood. Intrinsic membrane proteins designated aquaporins promote the selective movement of water or other and non-rutting seasons at different levels.