The development of human IgG monoclonal antibodies (MoAbs) to HIV has been very difficult and there are few reports on this in the literature. We have developed the methodology and verified our ability to regularly make human IgG anti-HIV MoAb-producing hybridomas from the lymph nodes and spleens of HIV-infected subjects. Eight stable hybridomas producing 2-5ug/ml (106cells)/d have been developed. These react with GP160/120, GP160/41, P55/24 and presumed conformational epitopes. One of these neutralizes HTLV-IIIB and another enhances infectivity. We hypothesize that human anti-HIV MoAbs which can neutralize HIV, mediate ADCC or C'lysis or can be cytotoxic to HIV-infected cells when coupled to toxins may be useful in AIDS prophylaxis or therapy. Furthermore, if anti-idiotype antibodies to our enhancing antibody could be developed using our hybridoma methodology, these might also potentially be useful clinically. In addition, we have also found that lymph node and spleen lymphocytes can be stored in liquid nitrogen and thawed up to one year later to yield cells which can readily be fused and made into hybridomas producing anti-HIV MoAbs. They, and other human anti-HIV MoAbs, may be useful in characterizing the antigens and epitopes recognized during the patient's immune response including those related to antibody mediated enhancement of infection. Lymph nodes and spleens, obtained at clinically relevant surgery will be processed as single cell suspensions, fused with our unique fusion partner (P3U1), screened by ELISA against HIV-infected and non-infected cells and cell lysates as well as defined relevant synthetic GP120 or GP41 epitopes and then cloned and expanded to produce specific MoAbs. These will be characterized for cellular and antigenic reactivity by immunofluorescence, flow cytometry, Western blotting and neutralization/enhancement assays. With our collaborators, we will prepare synthetic peptides which represent the already identified relevant eptitopes or GP120a and GP41 and identify the reactive epitope of each human MoAb. Based on our record of accomplishment, 10-20 MoAbs can be developed and characterized per year. Various clinically relevant experiments such as ADCC, neutralization by mixtures of MoAbs or MoAbs + patient sera, cytotoxicity of toxin-MoAb conjugates will be done to select promising MoAbs for clinical trials as well as potential diagnostic uses. Finally, we have initiated and will further exploit this unique resource and carry on the above described work.
