Genetically engineered HIV type 1 peptides as tools for the determination of anti-V3 loop antibody titers in sera...

Recombinant peptides from Escherichia coli encoding the principal neutralizing domain (PND) and surrounding sequences of gp120 of human immunodeficiency virus type 1 (HIV-1) with a C-terminal polyhistidine tag were expressed and purified on Ni(2+)-nitrilotriacetate agarose. High yields of more than 99% pure protein were obtained. Their serological reactivity with anti-HIV-positive and -negative human sera was compared to chemically synthesized V3 loop peptides. Overall the genetic PND peptides of the HIV-1MN isolate showed higher and broader reactivity patterns (84%) with HIV-positive sera from German patients than the chemically synthesized peptides (74%). By their higher reactivity and easy way of production and purification, recombinant peptides seem to be highly preferable for the determination of antibody titers to the PND of HIV-infected patients.