Endogenous expression of thermo-sensitive ion channels TRPV1 and TRPV4 in immune tissues of avian species (duck, Anas platyrhynchos)

Calcium signaling and body temperature are two important factors governing activation of immune cells. However, molecular identities of major players involved in such critical regulations are still unknown, especially in avian systems. In this work we explored the endogenous expression of Transient Receptor Potential Vanilloid subtype 1 and subtype 4 (TRPV1 and TRPV4) channels, in the immune cells and different tissues of duck (Anas platyrhynchos). TRPV1 and TRPV4 represent two important non-selective ion channels which are also thermo sensitive in nature. Using confocal microscopy we demonstrate that TRPV1 and TRPV4 are expressed endogenously in the duck immune system such as thymus, spleen, caecum and bursa. In thymus, bursa of Fabricius and caecum, these channels are differentially localized in the plasma membrane and intra-cellular regions. In addition, using Flow cytometry we demonstrate very specific expression of these two channels in Peripheral Blood Mononuclear Cells (PBMCs) and CD3+ve T cells. This result is the first report of endogenous expression of TRPV channels in cells and tissues relevant for avian immune system. Such findings may have importance in the context of immune functions and responses to pathological challenges faced by birds. Presence of these two important ion channels in the duck immune system may also have commercial importance in the context of livestock management, food supplement and production of quality poultry products.