Effect of HIV-1 infection on lymphocyte proliferation in gut-associated lymphoid tissue.

OBJECTIVE: To determine the change in the percentage of proliferative and activated lymphocytes in gut-associated lymphoid tissue (GALT) in HIV-1-infected subjects compared with that in uninfected controls.

METHODS: We measured the percentage of proliferative (Ki-67+) and activated (CD-69+, HLA-DR+, CD45RO+) lymphocytes from GALT and peripheral blood in chronically HIV-1-infected (12) and uninfected (9) individuals.

RESULTS: The percentage of proliferative GALT CD4+ T cells was increased in HIV-1-infected control subjects compared with that in uninfected controls (p <.007). Based on immunohistochemical staining, proliferative T cells were principally located in the parafollicular area surrounding lymphoid aggregates. The percentage of activated GALT lymphocytes, however, was not significantly different in HIV-1-infected individuals, whereas it was significantly increased in the peripheral blood of HIV-1-infected individuals. The percentage of peripheral blood lymphocytes trafficking to the intestine was also not significantly different in HIV-1-infected individuals compared with that in uninfected controls.

CONCLUSIONS: CD4+ T cell proliferation in GALT is increased in HIV-1 infection without a significant alteration in the percentage of peripheral blood T cells trafficking to the gastrointestinal mucosa.