Monoclonal antibodies against human immunodeficiency virus type 1 integrase: epitope mapping and differential effects on integrase activities in vitro

Abstract

Human immunodeficiency virus type 1 (HIV-1) integrase (IN) catalyzes the integration of viral DNA into the host chromosome, an essential step in retroviral replication. As a tool to study the structure and function of this enzyme, monoclonal antibodies (MAbs) against HIV-1 IN were produced. Epitope mapping demonstrated that the 17 MAbs obtained could be divided into seven different groups, and a selection of MAbs representing these groups were tested for their effect on in vitro activities of IN. Four groups of MAbs recognized epitopes within the region of amino acids (aa) 1 to 16, 17 to 38, or 42 to 55 in and around the conserved HHCC motif near the N terminus of IN. MAbs binding to these epitopes inhibited end processing and DNA joining and either stimulated or had little effect on disintegration and reintegration activities of IN. Two MAbs binding to epitopes within the region of aa 56 to 102 in the central core or aa 186 to 250 in the C-terminal half of the protein showed only minor effects on the in vitro activities of IN. Three MAbs which recognized an epitope within the region of aa 262 to 271 of HIV-1 IN cross-reacted with HIV-2 IN. MAbs binding to this epitope clearly inhibited end processing and DNA joining and stimulated or had little effect on disintegration. In contrast to the N-terminal-specific MAbs, these C-terminal-specific MAbs abolished reintegration activity of IN.

Anti‐integrase abzymes from the sera of HIV‐infected patients specifically hydrolyze integrase but nonspecifically cleave short oligopeptides

“…Therefore, it was interesting to analyze a possible homology of obmOP25, obmOP21, and rtOP to the complete protein sequence of IN. According to the literature, HIV IN has seven AGDs corresponding to its residues 5-22 (AGD1), 14-35 (AGD2) (Yi et al, 2000), 58-141 (AGD3), 141-172 (AGD4), 248-264 (AGD5) (Bizub-Bender et al, 1994), 208-228 (AGD6), and 251-271(AGD7) (Nilsen et al, 1996). Figure 6 demonstrates the sequence alignment of the nonspecific OPs and HIV IN.…”

Efavirenz enhances the proteolytic processing of an HIV‐1 pol polyprotein precursor and reverse transcriptase homodimer formation

“…Delaviridine was purchased from Biomol (Plymouth Meeting, PA). The monoclonal antibodies mAb 5B2 and mAb 6G5 were generously provided by Dag Helland and recognize both HIV-1 RT subunits [23] and the N-terminal 16 amino acids of the HIV-1 IN, respectively [24].…”

HIV integrase: a target for drug discovery

“…Recent developments of combinatorial libraries added another dimension to the entire pool of drug-lead compounds, since these complex libraries are independent of any functional bias. Building blocks of [72,144,145] combinatorial libraries are nucleotides, carbohydrates, amino acids or derivatives of these compounds, which results in complex libraries of millions of compounds.…”

“…Another class of IN inhibitors based on amino acids consists of antibodies. Several monoclonal antibodies have been described that target different IN domains [72,144,145]. The observations that HIV IN can accommodate 1 289-307 (1997) [300] and process other nucleotide or other phosphorylsubstrate analogues in the active site [24,25] suggest the possibility that nucleotide or nucleoside analogues might inhibit IN activity, especially those that are mimetic to the conserved viral DNA termini.…”