The CD4+ T-cell network and the cytokine profile after HIV-1 infection

The present article discusses CD4+ T-cell interaction and cytokine production after HIV-1 infection and progression to AIDS. On the basis of the experience of the author with biological fluids obtained from patients suspected of having AIDS and the recently available data concerning this matter, a model is proposed for the CD4+ T-cells network and CD4+ T-cells destruction during this infection. The mechanism of cellular killing involves apoptosis and preferential destruction of activated TH0/TH2-type cells. This type of cells is generated as an immune response to HIV-1 itself or to allergens and helminth infestations. The virus replicates more effectively in activated TH0/TH2-type cells and this contributes to the development of full-blown AIDS. The author has previously proposed the hypothesis of an elevation in IL-5 production during later stages of the disease and the use of eosinophilia of unknown etiology as a prognostic marker of AIDS in developing countries (Caterino-de-Araujo (1994). Immunology Today, 15: 498-499). At the present time, this proposition is confirmed and the use of eosinophilia as an indicator of a shift to a TH0/TH2-type response that predicts progression to AIDS is justified.