The transition from HLA-I positive to HLA-I negative primary tumors: the road to escape from T-cell responses.

The transition from HLA-I positive to HLA-I negative primary tumors: the road to escape from T-cell responses. Curr Opin Immunol. 2018 Mar 19;51:123-132 Authors: Aptsiauri N, Ruiz-Cabello F, Garrido F Abstract MHC/HLA class I loss in cancer is one of the main mechanisms of tumor immune escape from T-cell recognition and destruction. Tumor infiltration by T lymphocytes (TILs) and by other immune cells was first described many years ago, but has never been directly and clearly linked to the destruction of HLA-I positive and selection of HLA-I negative tumor cells. The degree and the pattern of lymphocyte infiltration in a tumor nest may depend on antigenicity and the developmental stages of the tumors. In addition, it is becoming evident that HLA-I expression and tumor infiltration have a direct correlation with tumor tissue reorganization. We observed that at early stages (permissive Phase I) tumors are heterogeneous, with both HLA-I positive and HLA-negative cancer cells, and are infiltrated by TILs and M1 macrophages as a part of an active anti-tumor Th1 response. At later stages (encapsulated Phase II), tumor nests are mostly HLA-I negative with immune cells residing in the peri-tumoral stroma, which forms a granuloma-like encapsulated tissue structure. All these tumor characteristics, including tumor HLA-I expression pattern, have an important clinical prognostic value and should be closely and routinely investigated in different ...
Source: Current Opinion in Immunology - Category: Allergy & Immunology Authors: Tags: Curr Opin Immunol Source Type: research