Sooraj Shah ’24
While much focus has been given to the COVID-19 pandemic, autoimmune diseases, such as lupus, also affect seven percent of the American population. Recent research suggests a potential link between mucosal-associated invariant T (MAIT) cells and the two diseases, as both COVID-19 and autoimmune diseases trigger increased MAIT cell response. A study led by Dr. Charles Vorkas, a professor in the Department of Microbiology and Immunology at Stony Brook University, used RNA sequencing to understand how and if MAIT cells respond to the diseases.
Researchers obtained peripheral blood mononuclear cells (PMBCs) from healthy and tuberculosis (TB) donor peripheral blood that consists of white blood cells, platelets, and red blood cells. The cells were cultured and subjected to flow cytometry, a method used to analyze the chemical and physical properties of the PBMCs. Researchers then labeled the cells for tracking and identified MAIT cells with flow cytometry. The cells were then subjected to antigen-specific activation and T-cell receptor stimulation, which enabled monitoring of MAIT cell activity and comparison of responses to healthy donor PBMCs using RNA sequencing.
The results showed that MAIT cells, previously thought to be a one-cell-type T-cell receptor cell, demonstrated heterogeneity. Heterogeneity, in biological terms, is defined as cells having diverse functions. More specifically, the MAIT cells were found to have distinct functions including those indicative of CD4⁺ and CD8⁺ cells. CD4⁺ cells are responsible for regulating the specific antigen immune response, while CD8⁺ cells induce direct cell death by lysis and apoptosis. The complex, multifunctional behavior of MAIT cells, Dr. Vorkas believes, may be a gateway to more targeted treatment.
The discovery of MAIT cells as heterogeneic opens a new door to the targeting of these cells by vaccines and immunotherapy. Future research should be conducted to better understand the specific responses of MAIT cells toward both diseases like COVID-19 and autoimmune conditions. MAIT cell research may lead to improved treatments for such diseases.
 C. Vorkas, et al. Single-cell transcriptional profiling reveals signatures of helper, effector, and regulatory MAIT cells during homeostasis and activation. The Journal of Immunology 208, 1042–1056 (2022). doi : https://doi.org/10.4049/jimmunol.2100522.