Antigen-dependent cytokine mRNA expression by individual rhesus macaque T helper cells by flow cytometry

Specific patterns of cytokine secretion by CD4(+) T helper (Th) cells deter mine the nature of immune effector responses. Using a multiparameter, flow cytometric fluorescent in situ hybridization (FISH) assay that detected cyt oplasmic mRNA within intact cells, we assessed antigen-specific cytokine ex pression in rhesus macaque Th cells. In the peripheral lymphocytes of immun ized rhesus macaques, FISH detected antigen-induced cytokine gene expressio n in single Th cells. Analysis of simultaneous cytokine expression by singl e cells demonstrated that the recall immune response consisted of Th cells expressing either a Th1 (IL-2(+)/IFN-gamma(+)) or a Th2 (IL-4(+)/IL-6(+)) c ytokine pattern. In addition to the classic Th subsets, Th cells expressing only one of two Th1 or Th2 defining cytokines were common following antige n restimulation, The data gathered with the FISH assay suggest that, in pri mates, the immune response to recall antigens consists of nonclassic Th cel ls, as well as a mixture of polarized Th1 and Th2 T cells. (C) 2000 Academi c Press.