Altered spleen-tumor TCR Vβ sharing and clonality with intrapleural VV-IL-2 therapy To identify changes in the splenic and tumor CDR3 migration and expansion, (A) the absolute number of shared TCR Vβ unique CDR3s between tumor and spleen was compared across systemic anti–PD-1 alone (n = 7), intrapleural VV-IL-2 alone (n = 9), and combination anti–PD-1 and VV-IL-2 (n = 8) treatment in the MPD mouse model. Compared with mice treated with anti–PD-1, combination therapy increased the number of shared TCR Vβ unique CDR3s. B, The fraction of spleen TCRVβ CDR3s found in TILTCRs was increased with VV-IL-2 treatment compared with anti–PD-1 therapy. C, TCRVβ clonality and the (D) alpha index, measures of highly clonal populations, were compared between spleen and tumor across treatments. Anti–PD-1 treated TILs exhibited the highest clonality with VV-IL-2 and combination therapy increasing spleen-specific clonality. P values are reported (*P < .05, **P < .01, ***P < .001).