Characterization of mutant flagellin proteins. Characterization of mutant flagellin proteins. Diagram of flagellin proteins used in this study (A). Circular dichroism melting curves are shown for the proteins. Melting temperature (Tm) values were determined as the inflection point of the sigmoidal melting curve (B). Coomassie-stained SDS-PAGE gel of FliCΔNaip5/6 and FliCΔTLR5 used in this study (C). WT mice were injected i.p. with 30 μg of FliC (n = 5), FliCΔNaip5/6 (n = 5), or FliCΔTLR5 (n = 5). Serum was collected 2 and 4 h after injections and cytokine levels were determined by ELISA. IL-12/23p40 (D) and IL-18 (E) statistical analysis was done using one-way ANOVA with Bonferroni multiple comparisons posttest. ***p < 0.001. Américo H. López-Yglesias et al. ImmunoHorizons 2019;3:422-432 Copyright © 2019 The Authors