We next investigated if the expansion of systemic SPAS-1+ CD8+ T cells was concomitant with increases of non-recirculating SPAS-1+ T cells in NLT distal to the tumor, specifically within the salivary gland, contralateral skin, and liver. Tumor neoantigen-specific SPAS-1+ T cells were significantly increased in each organ following dual therapy, when compared to anti-CTLA-4 monotherapy treatment (Fig. 7a). As these T cells also expressed CD69 and, in some cases CD103 (Fig. 7b; Supplementary Fig. 7a) surface markers consistent with tissue residency, we wanted to formally test if this increased population of cells was tissue-resident. To this end, we performed parabiosis surgery on tumor-free animals that had undergone therapy with either surgical tumor resection or IRE ablation to remove the tumor mass, followed in both cases by treatment with anti-CTLA-4 (Fig. 7c). After equilibration of blood (Fig. 7d), SPAS-1+ T cells isolated from salivary gland, contralateral skin, and liver showed a profound host bias (Fig. 7e, f), similar to that observed above (Fig. 3c). For example, over 90% of all tumor-specific T cells isolated in the SG were bona fide tissue-resident memory T cells. Thus, we concluded that dual therapy significantly amplified the number of SPAS-1+ CD8+ T cells in all NLTs assayed compared to mice that did not receive IRE. Taken together our data suggest tumor control after dual therapy is associated with increased frequency of SPAS-1-specific CD8+ T cells in circulation as well as in NLTs.
Ereflect Ultimate Memory 2011 Setup Free
2ff7e9595c
Comments