Adrenaline-induced mobilization of T cells in HIV-infected patients

The present study aimed to investigate lymphocyte mobilization from peripheral cell reservoirs in HIV-infected patients. Nine HIV-infected patients on stable highly active anti-retroviral therapy (HAART), eight treatment-naive HIV-infected patients and eight HIV(-) controls received a 1-h adrenaline infusion. The adrenaline infusion induced a three-fold increase in the concentration of lymphocytes in all three groups. All HIV-infected patients mobilized significantly higher numbers of CD8(+) cells but less CD4(+) cells. All subjects mobilized CD45RA(+)CD62L(+) and CD8(+)CD28(+) cells to a lesser extent than CD45RO(+)CD45RA(-) and CD8(+)CD28(-)cells. Furthermore, high numbers of CD8(+)CD38(+) cells were mobilized only in the HIV-infected patients. It was therefore predominantly T cells with an activated phenotype which were mobilized after adrenaline stimulation. It is concluded that the HIV-associated immune defect induced an impaired ability to mobilize immune-competent cells in response to stress stimuli. Furthermore, the study does not support the idea that CD4(+) T cells are trapped in lymph nodes by HIV antigens, because untreated and HAART-treated HIV-infected patients mobilized similar numbers of CD4(+) T cells. Finally, no evidence was found for the existence of a HAART-induced non-circulating pool of CD4(+) T cells.