Reversibility of the pathological changes in the follicular dendritic cellnetwork with treatment of HIV-1 infection

Over the course of HIV-1 infection, the lymphoid follicles where the humora l immune response is generated initially increase in size and number and th en progressively involute. In advanced disease, the network of the processe s of follicular dendritic cells (FDCs) that serve as antigen repositories a nd anatomical substrate for B and T cells and antigen to interact is destro yed, contributing to the breakdown of the immune system. Because destructio n of FDCs is associated with deposition of HIV-1, and much of the virus can be cleared from the network with antiretroviral therapy, we investigated t he reversibility of damage. We measured the immunohistochemically stainable FDC compartment by quantitative image analysis, and we documented changes in this compartment at different stages of disease. We show that treatment, initiated even at advanced stages of HIV-1 disease, can slowly reverse pat hological changes in the FDC network.