Natural Killer cells from primary human head and neck squamous cell carcinomas upregulate NKG2A

• Published in: The Journal of immunology (1950) 2017-05, Vol.198 (1_Supplement), p.130-130.18
• Main Authors: Korrer, Michael J, Kim, Young
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.198.Supp.130.18

Immunotherapy has revolutionized cancer therapy primarily by targeting checkpoint inhibitors found on endogenous immune cells. We analyzed and compared NK cells from the blood and tumor of HNSCC patients by flow cytometry for the expression of NK cell activating and inhibitory receptors. We found that NK cells from the primary tumor, but not the blood of HNSCC patients, significantly downregulated activating receptors NKG2D, DNAM-1, NKp30, CD16 and 2B4. Surprisingly, the majority of inhibitory KIR receptors on tumor-infiltrating NK cells were decreased compared to NK cells from the blood. However, the inhibitory receptors NKG2A and PD-1 were found to be highly overexpressed in tumor-associated NK cells. We believe that this study provides the first in-depth look at NK cells from primary HNSCC tumors. We found that tumor-associated NK cells express a profoundly different phenotype than NK cells from the blood of the same patients, with multiple activating receptors downregulated and the inhibitory receptor NKG2A over-expressed. These results support the therapeutic strategy of targeting NKG2A.