LACK OF EVIDENCE FOR THE DICHOTOMY OF T(H)1 AND T(H)2 PREDOMINANCE INHIV-INFECTED INDIVIDUALS

A switch from a T helper 1 (T(H)1) cytokine phenotype to a T(H)2 pheno type has been proposed as a critical element in the progression of hum an immunodeficiency virus (HIV) disease. Here, constitutive cytokine e xpression was analyzed in unfractionated and sorted cell populations i solated from peripheral blood and lymph nodes of HIV-infected individu als at different stages of disease. Expression of interleukin-2 (IL-2) and IL-4 was barely detectable (or undetectable) regardless of the st age of disease. CD8(+) cells expressed large amounts of interferon gam ma and IL-10, and the levels of these cytokines remained stably high t hroughout the course of infection. Furthermore, similar patterns of cy tokine expression were observed after stimulation in vitro of purified CD4(+) T cell populations obtained from HIV-infected individuals at d ifferent stages of disease. These results indicate that a switch from the T(H)1 to the T(H)2 cytokine phenotype does not occur during the pr ogression of HIV disease.