Invariant natural killer T cells from rhesus macaque spleen and peripheral blood are phenotypically and functionally distinct populations.

Background: Natural killer T cells (NKT) possess dual functions of innate and adaptive immune systems, controlling viral infections and regulating autoimmune diseases. Non-human primates (NHP) are penultimate models for advancing therapeutic immunoregulatory strategies for translational application in humans, though, little is known about NHP NKT cells. Here we characterized rhesus macaque NKT cells ex vivo.

Methods: The frequency, phenotype and intracellular cytokine production of V alpha 24+ 6B11+ invariant NKT (iNKT) cells were analyzed by multi-color flow cytometry. V alpha 24J alpha Q mRNA expression was analyzed by real-time RT-PCR.

Results: The frequencies of peripheral blood (PB) and spleen V alpha 24+ 6B11+ iNKT cells were not significantly different. The iNKT cell subset in spleen was significantly increased for CD4+ CD8+ and CD3+ CD56+ co-expression as well as intracellular interleukin-4 production, which was rarely observed in circulating PB.

Conclusion: Spleen iNKT cells in rhesus macaques are Th2 biased and display phenotypically and functionally distinct profiles from their PB counterpart.