The mRNA and lncRNA profiles of the T cells activated by breast tumor-specific DCs pulsed by MDA-MB-231 lysates at day 0, day 1 and day 6

Activation induced cell death (AICD) of T lymphocytes may be exploited by cancers to eliminate cytotoxic T cells (CTLs). Here, we demonstrated excessive apoptosis of tumor antigen-specific CTLs in breast and lung cancers. Interestingly, NKILA, an NF-κB interacting lncRNA, sensitizes CTLs to AICD by inhibiting NF-κB activities after their activation. In vivo, administering CTLs with NKILA silencing into immunocompromised mice with breast cancer patient derived xenografts (PDXs) effectively inhibits PDX growth by increasing CTL infiltration. Clinically, NKILA was overexpressed in the tumor specific CTLs of breast and lung cancers, which was associated with less CTL infiltration in the tumors and shorter patient survival. Our findings present the first evidence that AICD in patient tumor-specific CTLs is crucial to cancer immune evasion, and targeting NKILA in CTLs emerges as a novel anti-tumor immunotherapy. Mononuclear cells were obtained from peripheral blood of three HLA-A2+ healthy donors and cultured for 14 d in serum-free X-VIVO 20 medium (BioWhittaker, Walkersville, Maryland) with human GM-CSF (50 ng/ml; Peprotech) and IL-4 (20 ng/ml; Peprotech). Non-adherent DCs were enriched by depletion of contaminating T and B lymphocytes and pulsed for 20 h with lysates (200 μg protein/1 × 10^6 cells/ml) from MDA-MB-231 (HLA-A2+) that were lysed by 5 freeze/thaw cycles. T cells were incubated for 13 d in RPMI-1640 with 10% human AB serum (PromoCell) and IL-2 (25 U/ml; Peprotech) followed by incubation in the same medium with antigen-specific DCs (5:1) for 6 days. T cells were retrieved from the cocultures at day 0, day 1 and day6. Total RNA was extracted from T cells with indicated treatments (5 x 106 cells) using the TRIzol Reagent (Cat#A33251, Thermo Fisher). The quality of extracted RNA was assessed using the NanoDrop ND-2000 spectrophotometer.