Investigating mucosal associated invariant T (MAIT) cells in lymphangioleiomyomatosis (LAM)

Title: Investigating mucosal associated invariant T (MAIT) cells in lymphangioleiomyomatosis (LAM)
Author(s): S. Boyle A. Hogan A. Jouida MP. Keane C. McCarthy
Institution: University College Dublin
Poster: Click to view poster
Category: ILD
Abstract: Lymphangioleiomyomatosis (LAM) is a rare metastasising neoplasm that predominantly affects women of childbearing age. Abnormal proliferation of smooth muscle-like cells causes cystic destruction of lung parenchyma.(1) Mucosal associated invariant T (MAIT) cells are unconventional lymphocytes that are implicated in the pathogenesis of numerous diseases.(2) The aim of this research was to investigate if MAIT cells are altered in LAM.
Blood samples were obtained from a LAM patient cohort (n=10; 100% female) and healthy controls (n=8; 100% female). The peripheral blood mononuclear cells were stained using monoclonal antibodies specific for CD3, CD161, CD8 and TCR V alpha 7.2. MAIT cell frequency and phenotype were examined using multi-colour intracellular flow cytometry. The Mann-Whitney test was used to compare the groups.
There was no difference in CD3+ lymphocyte population (p=0.6965) or CD8+ T cell population (p=0.8112). MAIT cell frequency was reduced in the periphery of LAM patients (p<0.005). Additionally, the frequency of CD8+ MAIT cells was reduced in LAM patients (p<0.05).
MAIT cell frequency and the proportion of CD8+ MAIT cells are reduced in the periphery of LAM patients. Further studies are necessary to investigate the impact of LAM cells and the LAM tumour microenvironment on MAIT cell phenotypes, functional responses, and metabolism.

The author would like to acknowledge funding from the Pathological Society of Great Britain and Ireland.

1. O'Mahony A, Lynn E, Murphy D, Fabre A, McCarthy C. Lymphangioleiomyomatosis: a clinical review. Breathe. 2020;16(2):200007. DOI: 10.1183/20734735.0007-2020
2. Godfrey D, Koay H, McCluskey J, Gherardin N. The biology and functional importance of MAIT cells. Nature Immunology. 2019;20(9):1110-1128. DOI: 10.1038/s41590-019-0444-8