RE:RE:RE:RE:RE:RE:RE:RE:CD8+ TiLs and T-cell exhaustion"CD8+ T cell exhaustion is a stable dysfunctional state driven by chronic antigen stimulation in the tumor microenvironment (TME). "
https://pubmed.ncbi.nlm.nih.gov/37398660/
CD8+ TiL cells are critical mediators of cytotoxic effector function in cancer, however, in cancer, CD8+ TiL cells undergo a progressive loss of cytokine production and cytotoxicity, a state termed T-cell exhaustion as well as T-cell dysfuntion, resulting in a failure of T-cells to eradicate tumor cells in the tumor microenvironment (TME).
Also, high levels of PD-1 expression contribute to the characteristic dysfunction seen in exhausted CD8+ TiL cells. Correspondingly, in human tumors, a higher proportion of progenitor exhausted cells was associated with a greater likelihood of response to checkpoint blockade. While PD-1 blockade therapies have been successful in multiple tumor types, their effectiveness has been limited to between 10-20% of the patients treated.
Results from ONCY's AWARE-1 study showed that pelareorep treatment upregulated tumor PD-L1 expression, induced the generation and expansion of T cell clones, promoted tumor infiltration of CD8+ TiL cells, and increased the CelTIL score, a measure of tumor cellularity and inflammation associated with favorable clinical outcomes. Besides being able to overcome an immunosuppressive TME, pelareorp is a critical 'facilitator' in 'priming' the adaptive immune system in advance of PD-1 blockade, thus turning a 'cold' tumor into a 'hot' tumor that is more much conducive for PD-1 blockade, and a more effective I/O therapy than either agent alone.
https://www.newswire.ca/news-releases/oncolytics-biotech-r-and-solti-achieve-primary-endpoint-in-aware-1-study-871181269.html