CYTOTOXIC EFFECTOR CELL GRANULES RECOGNIZED BY THE MONOCLONAL-ANTIBODY TIA-1 ARE PRESENT IN CD8-NODES OF HUMAN IMMUNODEFICIENCY VIRUS-1-INFECTED PATIENTS( LYMPHOCYTES IN LYMPH)

A novel monoclonal antibody (mAB) TIA-1, which recognizes a 15-kd gran ule-associated protein of cytotoxic T lymphocytes and natural killer c ells, has been applied to sections of lymph nodes with human immunodef iciency virus (HIV)-induced lymphadenopathy (follicular hyperplasia an d lymphocyte depletion). The protein recognized by this mAB induces ap optosis in permeabilized lymphocytes in vitro. While this mAB reacted with approximately 46% of paracortical CD8+ cells in control nodes. It reacted with 75% of such cells in HIV-induced follicular hyperplasia. Germinal centers of the control nodes contained few TIA-1+ cells; in follicular hyperplasia caused by HIV-1, almost all germinal center CD8 + cells were TIA-1+. Both in the control nodes and in HIV-induced foll icular hyperplasia the majority of TIA-1+ cells coexpressed CD45R0. A marked loss of CD8+TIA-1+ cells was seen in lymphocyte-depleted nodes of patients with AIDS. The loss of these cytotoxic T lymphocytes may h ave a significant impact on the progression of the disease.