Down-regulation of macaque gamma delta plus T cells in lymphoid compartments after rectal infection with SIV smmPBj14

The dynamics of T cells expressing the gamma delta T-cell receptor in mucos ae and other compartments during the course of human immunodeficiency virus (HIV)-1 infection are poorly understood. To examine the impact of an acqui red immunodeficiency syndrome virus on the gamma delta + T-cell population, rectal inoculation of macaques with simian immunodeficiency virus (SIV)-PB j14 was used as a model. After rectal inoculation, five macaques were sacri ficed on days 4, 5, or 7 and then assessed for changes in the gamma delta T -cell receptor repertoire in different lymphoid compartments. There was dec reased representation of gamma delta + T cells in the intestinal mucosae, b lood, and spleens. Overall, the reduced number of total gamma delta + T cel ls was consistent with decreases in the V gamma or V delta T-cell sub-popul ations. Nevertheless, there was no consistent deletion or expansion of a se lected V gamma + or V delta + cell sub-population. These results demonstrat e that SIV-PBj14 replication and dissemination after mucosal inoculation re sulted in a decline of detectable gamma delta + T cells, suggesting that ma caque gamma delta + T cells are susceptible to down-regulation or destructi on during acute SIV-PBj14 infection.