Fig. 1: Optimizing immunization with iv4/iv9 in an adoptive transfer model.

a–f CD45.1⁺ wild-type mice (WT) received 500,000 CD45.2⁺ iGL-VRC01 cells, followed by immunization with iv4/iv9 or PBS formulated with either sigma adjuvant system (SAS) or Saponin/Monophosphoryl Lipid A nanoparticle (SMNP) the next day as indicated. Blood, spleens, and lymph nodes were collected 14 days later (a). ELISA was used to measure total serum IgG titers against eOD-GT8 (b) and eOD-GT8 KO (c). Frequency of CD45.2⁺ cells as proportion of total B cells in the spleen (d) or lymph nodes (e). Frequency of CD45.2⁺ cells as a proportion of germinal center (GC) cells in the lymph nodes (f). g CD45.1⁺ mice received indicated number of CD45.2⁺ iGL-VRC01 cells. h 24 h later, the frequency of CD45.2⁺ cells present in the spleens was analyzed by flow cytometry. P values are reported as determined by the Kruskal–Wallis test with Dunn’s multiple comparisons, and the dashed line indicates half the lowest dilution tested. i and j CD45.1⁺ WT mice received 5000 CD45.2⁺ iGL-VRC01 cells and were immunized 24 h later with iv4/iv9 + SMNP or PBS + SMNP. The frequency of CD45.2⁺ cells was measured in the spleen (i) or lymph nodes (j) 14 days later. Each data point represents one mouse. P values determined by Mann-Whitney tests. a and g were created using BioRender.