IMMUNOHISTOCHEMICAL RETRIEVAL OF THE PRINCIPAL HIV ANTIGENS P24, GP41, AND GP120 IN FORMALIN-FIXED TISSUE - AN INVESTIGATION USING HIV-INFECTED LYMPHOBLASTS AND POSTMORTEM BRAIN-TISSUE FROM AIDS CASES

This paper describes the use of an autoclaving procedure followed by i mmunocytochemistry to enhance the detection of the human immunodeficie ncy virus (HIV) antigens p24, gp41, and gp120. This procedure greatly improved the detection rate of the p24 and gp41 HIV surface antigens i n formalin fixed, paraffin wax embedded, HIV positive central nervous system (CNS) tissue while restricting staining to areas of the CNS sho wing evidence of neuropathology. However, the technique did not improv e retrieval of the gp120 antigen in either HIV positive, formalin fixe d CNS tissue or HIV infected T lymphoblasts. The inclusion of the high temperature autoclave step was validated using both HIV infected lymp hoblasts and preadsorption of the specific antibodies with the appropr iate recombinant HIV proteins. Using the methodology described here, f ormalin fixed CNS tissue from potential or known HIV positive cases ca n be processed reliably and safely. To ensure the reliability of this technique, it is recommended that an assessment of both the p24 and gp 41 antigens is undertaken.