Fig. 2. HSD tumor immunity is mediated by elevated NK cell frequency and activation.

Tumor-infiltrating immune cells isolated from B16 melanoma were profiled for immune cell population through flow cytometry after excising the tumor at the end point. The results from immunophenotyping was then analyzed by using graph pad and was plotted as bar graphs representing mean % positive cells ± SEM along with representative FACS zebra plot and (A) representative t-distributed stochastic neighbor embedding (tSNE) plot depicting clusters and counts of NK, γδT, CD4, and CD8 cells. (B) B16 melanoma progression in RAG1^−/− mice and its (C) survival cure. (D to F) Immunophenotyping for NK cells; expression of CD107a, CD96, and PD1 molecule on NK cells; and expression of IFNγ and TNFα by NK cells. (G) Relative mRNA expression of NK cell–associated genes from tumor-infiltrating immune cells samples. (H) Schematic representation for (I) progression of B16 melanoma in the presence of HSD with or without NK cell depletion and (J) its profiling for NK cells. (K) Schematic representation for the effect of neutralization of IFNγ on (L) B16 melanoma progression and (M) changes in NK cells and IFNγ expressed by NK cells. (N) Levels of serum cytokines evaluated through ELISA. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 (Student’s t test or one-way ANOVA).