| First Author | Verkoczy L | Year | 2013 |
| Journal | J Immunol | Volume | 191 |
| Issue | 5 | Pages | 2538-50 |
| PubMed ID | 23918977 | Mgi Jnum | J:205800 |
| Mgi Id | MGI:5546467 | Doi | 10.4049/jimmunol.1300971 |
| Citation | Verkoczy L, et al. (2013) Induction of HIV-1 broad neutralizing antibodies in 2F5 knock-in mice: selection against membrane proximal external region-associated autoreactivity limits T-dependent responses. J Immunol 191(5):2538-50 |
| abstractText | A goal of HIV-1 vaccine development is to elicit broadly neutralizing Abs (BnAbs). Using a knock-in (KI) model of 2F5, a human HIV-1 gp41 membrane proximal external region (MPER)-specific BnAb, we previously demonstrated that a key obstacle to BnAb induction is clonal deletion of BnAb-expressing B cells. In this study of this model, we provide a proof-of-principle that robust serum neutralizing IgG responses can be induced from pre-existing, residual, self-reactive BnAb-expressing B cells in vivo using a structurally compatible gp41 MPER immunogen. Furthermore, in CD40L-deficient 2F5 KI mice, we demonstrate that these BnAb responses are elicited via a type II T-independent pathway, coinciding with expansion and activation of transitional splenic B cells specific for 2F5's nominal gp41 MPER-binding epitope (containing the 2F5 neutralization domain ELDKWA). In contrast, constitutive production of nonneutralizing serum IgGs in 2F5 KI mice is T dependent and originates from a subset of splenic mature B2 cells that have lost their ability to bind 2F5's gp41 MPER epitope. These results suggest that residual, mature B cells expressing autoreactive BnAbs, like 2F5 as BCR, may be limited in their ability to participate in T-dependent responses by purifying selection that selectively eliminates reactivity for neutralization epitope-containing/mimicked host Ags. |
