Growth failure and AIDS-like cachexia syndrome in HIV-1 transgenic mice

The mechanisms which predispose to growth failure in infants and children infected with immunodeficiency virus type-1 (HIV-1) are not fully understood. The contributions of viral replication and CD4+ T cell depletion to growth failure in an HIV-1 transgenic mouse model were investigated. Mice homozygous for the transgene, a gag-pol deletion mutant of the HIV-1 provirus pNL4-3, exhibited marked cachexia, growth retardation, lymphoproliferation with a reduction in the percentage of CD4+ T cells but an increase in the absolute number of splenic CD4+ and CD8+ T cells, thymic hypoplasia, and early death. Despite the absence of T cells, athymic nude mice, homozygous for the HIV transgene, displayed comparable growth failure. The results indicate that AIDS-like cachexia may be produced by expression of viral envelope or accessory genes, need not be accompanied by absolute depletion of CD4+ T cells, and may occur independent of T cell function.