Molecular characterization of a human anti-HIV 1 monoclonal antibody revealed a CD26-related motif in CDR2

Mimicking the humoral immune response in vitro results in antigen‐specific isotype switching supported by specific autologous T helper cells: generation of human HIV‐1‐neutralizing IgG monoclonal antibodies from naive donors

“…Briefly, peripheral blood mononuclear cells (PBMC) were treated with L-leucyl-L-leucine methyl ester (LeuLeuOMe) (Bachem Feinchemikalien AG, Budendorf, Switzerland) [5]. An in vitro stimulation was performed by culturing LeuLeuOMe-treated PBMC on irradiated (4000 rad) PBMC at 1 : 1 ratio (1 x lo6 cells/ml) in RPMI 1640 medium, supplemented with 5 % human serum and 10 pM ptt.…”

“…Wells containing antigen-specific antibodies were identified and immediately subjected to electrofusion as previously described [5] , with modifications described by Steenbakkers et al [9] for fusion of non-transformed B cells. The fusion medium was an iso-osmolar solution (280 mM sorbitol, 0.5 mM magnesium acetate, 0.1 mM calcium acetate, 1 mg/ml bovine serum albumin, pH 6.9-7.1) and the fusion partner was the mouse x human heteromyeloma cell line K6H6/B5 [lo], which was maintained in medium, supplemented with 10 % FCS.…”

“…The primary in vitro immunization was performed, as previously described [5]. Briefly, PBMC were isolated from healthy donors who were HIV-1 seronegative for at least 6 months after blood donation.…”

“…The induction of a primary, antigen-specific IgM response against a peptide containing both a B and T cell epitope, was recently demonstrated to be dependent on specific T memory cells in vitro [5]. In the present investigation, we have simulated in vitro some of the signaling occurring in germinal centers, by exposing primary immunized human B cells to rescue and proliferation signals, in analogy to the basal light zone events, and later to antigen-specific T helper cells of the Tho type, which mimicks apical light zone differentiation.…”

Pseudopeptide TASP Inhibitors of HIV Entry Bind Specifically to a 95-kDa Cell Surface Protein

“…Accordingly, throughout the years, several potential cofactors of CD4 have been proposed (1). By biochemical approaches, different cell surface proteins have been reported to interact with the V3 loop of gp120 (15)(16)(17)(18)(19)(20) and gp41 (21)(22)(23)(24); however, in most cases the relationship between the interaction and a putative role in HIV infection has not been determined. We have previously reported that CD26, through a potential interaction with the V3 loop, may serve as a cofactor of HIV entry (25)(26)(27).…”