A method for identification of HIV gp140 binding memory B cells in human blood

Abstract

Antibodies to HIV are potentially important reagents for basic and clinical studies. Historically, these reagents have been produced by random cloning of heavy and light chains in phage display libraries [Burton, D.R., Barbas, C.F. III, Persson, M.A.A., Koenig, S., Chanock, R.M., and Lerner, R.A., (1991), A large array of human monoclonal antibodies to type 1 immunodeficiency virus from combinatorial libraries of asymptomatic seropositive individuals. Proc. Natl. Acad. Sci. U. S. A. 88, 10134-10137.] and electrofusion techniques [Buchacher, A., Predl, R., Tauer, C., Purtscher, M., Gruber, G., Heider, R., Steindl, F., Trkola, A., Jungbauer, A., and Katinger, H., (1992), Human monoclonal antibodies against gp41 and gp120 as potential agent for passive immunization. Vaccines 92, 191-195]. Here we describe a method to identify and potentially enrich human memory B cells from HIV infected patients that show serum titers of neutralizing antibodies. When biotinylated gp140 is used to stain peripheral blood mononuclear cells it identifies a distinct population of gp140 binding B cells by flow cytometry.

Figure 1. Gp140 staining of peripheral blood B cells

Gating strategy for GP140 binding IgG⁺ B cells from a HIV-1 infected patient and healthy control. 1A and 1b show the patient and control respectively. The plots on the left show the gating on lymphocytes according to their size and granularity, the plots in the middle indicate the gating for IgG⁺CD19⁺ B cells and the plots on the right show the gating of IgG⁺CD19⁺gp140⁺ cells. Numbers indicate the frequency of cells in the lymphocyte gate (left) and the frequency of CD19+IgG+ B cells (center) and gp140- binding CD19+IgG+ B cells (right) among all gated lymphocytes.