Figure 6.

Sensing through MyD88 enhances the potency of mRNA-LNP vaccines but is not required for LNP adjuvanticity

Myd88^−/−, Mavs^−/− and control mice received a single IM immunization with 30 μg PR8 HA mRNA-LNP or 30 μg rHA + eLNP. Tfh and GC B cell responses were examined 12 days after immunization in dLNs by flow cytometry.

(A and B) Tfh cell (CD4⁺B220⁻CD44^hiCD62L⁻Bcl6⁺CXCR5⁺) representative flow cytometry (A) and percentages and absolute numbers (B) in Myd88^−/− and control mice.

(C and D) GC B cell (CD3⁻CD19⁺FAS⁺GL7⁺) and HA-specific GC B cell (RBD⁻HA⁺) representative flow cytometry (C) and percentages and absolute numbers (D).

(E and F) Percentages and absolute numbers of Tfh cells (E) and absolute numbers of GC B cells and HA-specific GC B cells (F) in Mavs^−/− and control mice.

In (A)–(D), n = 7–8 mice/group. In (E) and (F), n = 6 mice/group. Data were combined from three independent experiments in (A)–(D) and two independent experiments in (E) and (F). In (B) and (D)–(F), symbols represent individual animals. Data shown are mean + SEM. Statistical analysis: unpaired two-tailed Mann-Whitney U test was conducted. ^∗p ≤ 0.05, ^∗∗p ≤ 0.01, ^∗∗∗p ≤ 0.001, ^∗∗∗∗p ≤ 0.0001.