TRANSMISSION OF DENGUE VIRUS-SPECIFIC SUPPRESSOR SIGNAL DEPENDS ON THE PRESENCE OF CALCIUM

The present study was undertaken to investigate the role of calcium in the production of dengue type 2 virus (DV) induced suppressor cytokin e (SF) and in transmission of the suppressor signal via syngeneic macr ophage (M phi) to recruit the second subpopulation of suppressor T(TS2 ) cell. Effect of calcium channel blocking drugs, Verapamil and Nifedi pine, on the production and activity of SF was investigated. The produ ction of SF was inhibited in a dose dependent manner by the calcium ch annel blockers. The suppressor activity of SF was also inhibited by ca lcium channel blocking drugs. SF could not be produced when spleen cel ls were cultured in a calcium free medium, the production being restor ed on substitution with calcium chloride. Treatment of M phi with the calcium channel blockers inhibited the transmission of the suppressor signal from TS1 to TS2 cells in a dose dependent manner. The influx of calcium during transmission of the suppressor signal was studied by m easuring the Ca-45 uptake. Calcium channel blocking drugs inhibited th e Ca-45 uptake by T lymphocytes. Thus, presence of calcium is obligato ry for the production and suppressor activity of SF and it plays a cri tical role in transmission of the suppressor signal.