Fig. 7. Anti-FcγRIIIB-antigen conjugate is anti-tumorigenic  in FcγR humanized mice and converts human neutrophils into nAPCs that activate autologous T cells.

a, b Schematic for the timeline of indicated treatments for examining the effect of 3G8-fOva on B16F10-Ova tumor growth (top panel). Tumor volume was assessed at indicated times after s.c. injection of B16F10-Ova melanoma cells. The number of mice per group is in parenthesis (lower panel). Representative images of harvested tumors are shown, scale bar = 5 mm (a). Spleens of indicated mice from (a) at tumor harvest were analyzed for frequency of Ova-peptide specific effector CD8⁺ T cells (CD62L^lo CD44^hi) using MHCI-tetramers (tet+), and CD4⁺ and Treg (Foxp3⁺, CD4⁺) cells (b). c Neutrophils from a patient with primary myelofibrosis (a myeloproliferative neoplasm, MPN) or acute myeloid leukemia (AML) (AML-2.1, AML-2.2 representing two independent blow draws) were treated with 3G8-conjugate (3G8-fOva) or isotype, cultured for 2 days and then co-cultured with autologous T cells and analyzed for IFN-γ secretion on a human IFN-γ ELISpot plate. The percent nAPC generation is shown in the table (avg ± s.e.m.). T cell responses quantified as the number of spots per 1 × 10⁶ cells on a human IFN-γ ELISpot plate is reported and representative images of the same are shown. d Autologous T cell responses against diphtheria toxin (Dipt) or tetanus toxoid (Tet) loaded isotype or 3G8-fOva (3G8-conj) treated neutrophils from normal human volunteers were evaluated using an IFN-γ ELISpot plate as in (c). Representative images are shown. Data are mean ± s.e.m. One-way analysis of variance and Dunnett’s multiple comparison test was used for comparison of multiple groups except for a), for which statistical analysis is described in Supplementary Fig. 7a. *p < 0.05, **p < 0.005.