Tumor infiltrating lymphocyte therapy for renal cell carcinoma: methods for ex vivo expansion and T-cell memory induction

Tumor infiltrating lymphocyte (TIL) therapy is a personalized treatment for locally advanced or metastatic cancer. TIL therapy requires the surgical excision of a portion of the malignant tissue and subsequent ex vivo expansion of tumor reactive immune cells, primarily T-lymphocytes (T-cells), prior to reinfusion into the patient. TIL therapy has been shown to be efficacious in numerous forms of cancer; however, a lack of consistent in vitro TIL production has hindered the development of this potentially curative cell therapy for renal cell carcinoma (RCC). I (Mitchell W. Braun) report my work, in the Godwin research laboratory, which has aimed to advance the prospect of TIL therapy for RCC. A novel method for TIL expansion has been developed that has shown a 94% success rate for creating TIL cultures from clear cell RCC. This method generates a TIL product with an optimal phenotype relative to other established TIL production protocols, namely the pre-rapid expansion protocol (PreREP)/REP and FTD + beads method. PreREP involves IL-2 supplementation alone as the source of exogenous stimulation during the first phase of expansion. The fresh tumor digests (FTD) + beads method involves supplementation of IL-2, as well as anti-CD3/CD28 beads to initiate TIL cultures. Relative to the PreREP and FTD + beads protocols, our method involves adherent cell depletion (ACD), referred to as panning, and generates significantly fewer regulatory (CD4+/CD25+/FOXP3+) (p=0.049, p=0.005), tissue-resident memory (CD8+/CD103+) (p=0.027, p=0.009), PD1+/TIM-3+ double-positive (p=0.009, p=0.011) and TIGIT+ T-cells (p=0.049, p=0.026), respectively. These phenotypic changes were achieved while increasing the average tumor reactive T-cell yield in the final TIL product. However, using this method a majority of the CD8+ expanded TILs bear an effector-memory or effector phenotype, which is sub-iv optimal for adoptive transfer and similar to the other protocols. Therefore, various methods to induce a less differentiated phenotype during in ...