Fig. 6: 10E8-GT10.3 improves sustenance of 10E8-UCA^H B cells in GCs.

a, Location of mutations introduced in 10E8-GT10.2 to generate 10E8-GT10.3 (MPER, purple; scaffold backbone, cyan; mutations, orange). b, Affinities of human 10E8-UCA^H/UCA^L Fab and Fabs of 10E8-UCA^H/mouse^L antibodies (sorted based on B220⁺IgM⁺ expression on B cells) to 10E8-GT10.2 12mer and 10E8-GT10.3 12mer in nanoparticle SPR assays. Symbols represent individual antibodies, and lines represent 10E8-UCA^H/mouse^L medians. c,d, Representative flow cytometry plots of CD45.2⁺ and CD45.1⁺ B cells (c) and percentages of CD45.2⁺ B cells (d) in spleen GCs at days 7, 14 and 21 p.i. in CD45.1 wild-type mice transferred with CD45.2 10E8-UCA^H B cells to reach 1:10⁴ 10E8-UCA^H B cells and immunized 1 day later with 5 µg of 10E8-GT10.2 12mer, 10E8-GT10.3 12mer or 10E8-GT9-KO 12mer with alhydrogel. Data in d are pooled from two independent experiments (n = 5–8). Error bars indicate mean ± s.d. from mice in pooled groups. Significance was calculated with a Student’s t-test (unpaired, two tailed). e, Affinities of mAbs expressed from epitope-specific 10E8-UCA^H CD45.2⁺GT10⁺⁺KO⁻ GC B cells (GT10.3-10E8-UCA^H mAbs) and endogenous CD45.1⁺GT10⁺⁺KO⁻ GC B cells (GT10.3-WT mAbs) at days 7, 14 and 21 p.i. with 10E8-GT10.3 12mer as in c and the affinity for corresponding iGL sequences (naive), as measured by monomer SPR assay. Circles represent individual antibodies, and lines indicate median values. f, Representative immunohistochemistry image of a spleen section at day 21 p.i. from a mouse immunized with 10E8-GT10.3 12mer and alhydrogel, as in c (left), and percentage of total GCs containing CD45.2⁺ B cells (right). White boxes show GCs with CD45.2⁺ B cells. Scale bar, 200 μm (left). g, Phylogenetic tree of IGHV sequences from 10E8-UCA^H B cells, colorized on the basis of affinities at day 21 p.i., as in e.