Flow cytometric determination of cytokines in activated murine T helper lymphocytes: Expression of interleukin‐10 in interferon‐γ and in interleukin‐4‐expressing cells

Abstract

In an immune response, effector functions are controlled by T helper (Th) 1 cytokines [interferon‐γ (IFN‐γ), interleukin (IL)‐2 and tumor necrosis factor‐β] and Th 2 cytokines (IL‐4, IL‐5 and IL‐10). Here we analyze by multiparameter immunofluorescence to what extent IL‐2, IL‐4, IL‐5, IL‐10 and IFN‐γ are co‐expressed in individual normal murine Th cells upon activation in vitro with the bacterial superantigen Staphylococcus aureus enterotoxin B, presented in the context of major histocompatibility complex class II. IL‐2 and IFN‐γ are co‐expressed by some, but not by other Th cells. Expression of IL‐4 and IFN‐γ is exclusive. IL‐10 is co‐expressed in individual cells either with IL‐4 or with IFN‐γ. No IL‐5‐expressing cells are detected. While IL‐10‐ and IL‐4‐co‐expressing Th cells correspond to classical Th 2 cells, cells co‐expressing IL‐10 and IFN‐γ could be involved in negative‐feedback regulation of a Th 1 response. Apart from such functional implications, our results show that IL‐2, IL‐4, IL‐5, IL‐10 and IFN‐γ are expressed independently of each other in individual murine Th cells.