AN INCREASE IN P50 P65 NF-KAPPA-B BINDING TO THE HIV-1 LTR IS NOT SUFFICIENT TO INCREASE VIRAL EXPRESSION IN THE PRIMARY HUMAN ASTROCYTE/

Human astrocytes can be infected with HIV-1 both in vivo and in vitro. The amount of HIV-1 p24 structural protein production is low in compa rison to that of the macrophage. Several weeks following infection or transfection, however, coculivation with uninfected lymphocytes or sti mulation with the cytokines TNF-alpha and IL1-beta will increase viral production from this cell type. In the present study we demonstrate t hat phorbol 12-myristate 13-acetate (PMA) also increases HIV-1 p24 pro duction from the primary human astrocyte. Using electrophoretic mobili ty shift assay (EMSA) in combination with supershift studies using spe cific antibodies, we demonstrate that PMA, like TNF-alpha increases th e p50/p65 form of NF-kB. Furthermore we demonstrate that the protein k inase inhibitor H7 inhibits PMA- and TNF-alpha-associated increases in HIV-1 expression at a time when it has little to no inhibitory effect on the associated increases in p50/p65 NF-kB. Thus, unless p50/p65 NF -kB or its binding is affected by H7 in a manner that cannot be resolv ed by EMSA, an increase in this form of NF-kB is not always sufficient to increase HIV-1 expression from the astrocyte. (C) 1994 Academic Pr ess, Inc.