Figure 3. Antibody responses arise from cognate T-B interaction and are not associated with inflammation.

(a) Peptide co-assemblies are proposed to function similar to an adjuvanted peptide-protein conjugate, as described in the text. (b) Antibody responses required co-assembled fibers; mice injected simultaneously with separate solutions of E214Q11 and PADREQ11 fibers failed to raise a response by 7 days after a boost (n = 5 mice per group, two-tailed t-test). (c) Peptide assemblies did not induce recruitment of inflammatory cells after i.p. injection. Cells in the peritoneal lavage fluid were analyzed 20 hr after injection. N = 4 mice per group. *, p <0.05 compared to EQ11 group, by two-way ANOVA with Dunnett correction for multiple comparisons. The immunizations were as follows (100 μL per injection): E-Q11 (1 mM E214-Q11, 1 mM Q11), E-Q11 +Alum (2 mM E214-Q11, 2 mM Q11, mixed 1:1 v/v with Imject Alum), E-Q11/PQ11 (1 mM E214-Q11, 0.95 mM Q11, 0.05 mM PADRE-Q11), PBS (saline). Abbreviations: Macrophages (mac), conventional dendritic cells (cDC), inflammatory DCs (iDC), plasmacytotoid DC (pDC), neutrophils (neut), inflammatory monocytes (iMono), eosinophils (eosi), as defined in ref (^[19]). (d,e) C57Bl/6 mice were immunized and boosted with 2 mM OVAQ11 alone, co-assembled with 0.1 mM PADREQ11, or adjuvanted with Imject alum. (e) The pOVA-specific IgG titers were enhanced by co-assembly with PADREQ11 (p = 0.051 by two-way ANOVA over 9 weeks) to levels that equaled the alum-adjuvanted response after one boost. (e) After immunization co-assembled fibers, the T cell response was divided between pOVA and PADRE instead of being focused exclusively on pOVA. Mean + standard deviation is shown; n = 5 mice per group.