CONCLUSION: AN INTEGRATED VIEW

Taken together, HIV infection is associated with an increased level of T cell apoptosis, which, by itself, is not inappropriate, because it is part of the physiological response to immune activation.

FIGURE 19.1 Increased naive T cell consumption due to immune hyperactivation. Thymic output of T cells to the naive compartment is low and constant in healthy as well as in HIV-infected adults. As one ages, upon encountering infections, naive cells will enter the memory/effector T cell pool, leading to a gradual decrease in the naive T cell compartment. Upon infection, activated and expanded cells will die of activation-induced cell death (AICD). During HIV infection, the same process occurs, only at a faster rate due to chronic immune activation by the virus. (Adapted from Hazenberg, M.D., et al., Nat. Immunol., 1, 285-289, 2000.)

ACKNOWLEDGMENT

We would like to thank Rob de Boer for critical reading of this manuscript. This research has been financially supported by AIDS Fond Netherlands (grants 7010 and 7011) and The Netherlands Organization for Scientific Research (916.36.003).

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