Increased tumor infiltration by mucosal-associated invariant T cells correlates with poor survival in colorectal cancer patients.
The infiltration of tumors by lymphocytes is a prognosis factor in colorectal cancer (CRC). The magnitude and quality of this infiltration have emerged as important component of the clinical outcome in these patients. Specifically, markers associated with functional cell-mediated immunity, i.e., a Th1 immune response, are independent markers of better prognosis, whereas Th17-associated components are deleterious and correlate with poorer survival. Mucosal-associated invariant T (MAIT) cells are a recently described T cell subset with tissue-homing properties. They display a restricted TCR repertoire specific for widely conserved microbial ligands, and display anti-bacterial properties upon release of Th1-like, Th17-like, and/or cytotoxic granules. MAIT-cell-specific transcripts have been found in kidney and brain cancer, but have not been studies in other sites. In this study, we retrospectively analyzed by confocal microscopy the presence of MAIT cells within colorectal tumors as compared with paired healthy tissues. We observed a significant although variable increase, both in density and in proportion of overall tumor-infiltrating T lymphocytes inside the tumors. Importantly, survival curves as well as multivariate analysis showed that patients displaying a higher recruitment of MAIT cells in their tumor, as compared with the neighboring healthy tissue, showed a less favorable clinical outcome. This study suggests that including MAIT-cell-specific markers or transcripts in the analysis of tumor-infiltrating lymphocytes could be a benefit to the diagnosis and follow-up of CRC patients.
EA4666, University of Picardie-Jules Verne, Amiens, France.|ICAP Platform, University of Picardie-Jules Verne, Amiens, France.
Luciane
L
Zabijak
Pathology Department, CHU Amiens, Amiens, France.
Christophe
C
Attencourt
EA4666, University of Picardie-Jules Verne, Amiens, France.|Immunology Laboratory, CHU Amiens, Amiens, France.
Caroline
C
Guignant
Pathology Department, CHU Amiens, Amiens, France.
Denis
D
Chatelain
ICAP Platform, University of Picardie-Jules Verne, Amiens, France.
Paulo
P
Marcelo
EA4666, University of Picardie-Jules Verne, Amiens, France.|Hematology Department, CHU Amiens, Amiens, France.
Jean-Pierre
JP
Marolleau
EA4666, University of Picardie-Jules Verne, Amiens, France. emmanuel.treiner@inserm.fr.|Immunology Laboratory, CHU Amiens, Amiens, France. emmanuel.treiner@inserm.fr.|Inserm UMR1043, CHU Purpan, BP 3028, 31024, Toulouse Cedex 03, France. emmanuel.treiner@inserm.fr.
Emmanuel
E
Treiner
D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D016246:Lymphocytes, Tumor-Infiltrating / Q000378:metabolism*; D008297:Male; D009092:Mucous Membrane / Q000166:cytology; D012189:Retrospective Studies; D016176:T-Lymphocyte Subsets / Q000276:immunology*
Colorectal cancer; IL-17; MAIT cells; Mucosal-associated invariant T cells; Prognosis; Tumor-infiltrating lymphocytes