MONOCLONAL-ANTIBODIES AGAINST HIV TYPE-1 INTEGRASE - CLUES TO MOLECULAR-STRUCTURE

Eleven murine hybridoma clones were selected for their ability to prod uce anti-HIV-1 integrase (IN) antibodies. Competition and epitope mapp ing studies allowed segregation of the monoclonal antibodies (MAbs) in to four distinct classes. The five MAbs that comprise the first class showed high affinity for epitopes within an N-terminal domain of 58 am ino acids that includes a conserved zinc finger moth. The second class , with two MAbs, showed high affinity for epitopes within 29 amino aci ds at the C terminus. Another two MAbs, which constitute the third cla ss, displayed moderate affinities for epitopes that mapped to regions within the highly conserved catalytic core referred to as the D,D(35)E domain. One of these MAbs showed significant cross-reactivity with HI V-2 LN and weak, but detectable, cross-reactivity with RSV IN. The rem aining two MAbs, which comprise the fourth class, exhibited fairly low binding affinities and appeared to recognize epitopes in the zinc fin ger moth domain as well as the C-terminal half of the LN protein. The MAbs can be used for immunoprecipitation and immunoblotting procedures as well as for purification of HIV-1 IN protein by affinity chromatog raphy. We show that several can also be used to immunostain viral ZN s equences in HIV-1-infected T cells, presumably as a component of Gag-P ol precursors. Finally, analysis of our mapping and competition data s uggests a structure for mature ZN in which the C terminus approaches t he central core domain, and the N and C termini touch or are proximal to each other. These MAbs should prove useful for further analyses of the structure and function of IN both in vitro and in vivo.