Figure 1. NEF expression in CD4 T cells blocks their T helper function resulting in a lack of antibody production.

• A
  Outline of the experimental setup to assess the immunomodulatory effects of HIV‐1 NEF on the generation of humoral immune responses. Antigen‐specific interactions are established using HEL‐OVA as model antigen with HEL‐specific SW_HEL B cells (B_HEL) and OVA‐specific OT‐II CD4 T cells (CD4_OT‐II).
• B, C
  Levels of anti‐HEL IgG in serum as measured by ELISA at the indicated days post‐immunization with HEL‐OVA/CFA following adoptive transfer of B_HEL cells without CD4_OT‐II cells (no T‐cell control) or with control CD4_OT‐II cells or NEF‐expressing CD4_OT‐II cells. (B) NEF WT of HIV‐1_SF2 (C) patient‐derived NEF variants. Shown are relative levels of HEL IgG production with the mean of IgG levels in mice receiving control cells between days 12–14 post‐immunization arbitrarily set to 1. Each dot represents one animal. Bars represent mean values with SD from 2 to 10 mice analyzed from 3 (B) and 2 (C) independent experiments. Statistical significance was assessed by Mann–Whitney U‐test. ***P ≤ 0.001, *P ≤ 0.05.