Figure 1.

Human Hematopoietic Cells Can Secrete Broadly Neutralizing Antibodies In Vitro

PGT128 or VRC01 bNAb secretion by human THP-1 monocytic cell line (A), primary human CD3⁺ T cells (B), adult (C), or fetal liver CD34⁺ cells (D) was quantified by ELISA from cell-free supernatants at the indicated time points following transduction. GFP expression was determined at the same time points by flow cytometry and represented as dashed lines (right y axes). THP-1 cells were cultured at a cell density of 4 × 10⁵ cells/mL, T cells at 2 × 10⁶ cells/mL, and adult and fetal liver HSPCs at 1 × 10⁶ cells/mL. (E) TZM-bl neutralization assay using cell-free supernatants harvested from the indicated human fetal liver cells (5 days post-transduction) measured at 2 days post-infection with HIV-1 BaL. Data are represented as means of two to three replicates from one representative experiment. Error bars represent SDs.