Evaluation of MAIT cells in patient recently diagnosed as cancer breast and its correlation with clinical outcome.

Mucosal Associated Invariant T cells are a population of unconventional T cells which are enriched in mucosal tissues such as the lung and gut but are also present in other tissues including the skin, adipose tissue and the liver [4,5,6,7]. Unlike conventional T cells, MAIT cells are not restricted by MHC but recognize the MHC-related protein MR1. MAIT cells express a semi-invariant TCR α-chain (Vα7.2-Jα33/20/12 in humans) and a limited repository of TCR-β chains, mostly from the TRBV20 and TRBV6 gene families [8,9]

MAIT cells can also be activated independent of TCR engagement, via pro-inflammatory cytokines such as IL-18 [10,11,12]. Upon activation, MAIT cells can rapidly respond, producing a milieu of cytokines including interferon-gamma , tumor necrosis factor alpha and interleukin-17 [11,14]. MAIT cell cytokine profiles can vary depending on their tissue localization [15].

Peripheral MAIT cells are potent producers of IFNγ and TNFα, whereas IL-17 producing MAIT cells are rare in the periphery but are more abundant in, for example, the female genital mucosa [16]. In addition to cytokine production, A central role in immune protection against cancer is played by T lymphocytes, particularly CD8+ T cells .Their infiltration in tumor cell nests is usually associated with a favorable prognosis and may predict outcome of therapies with drugs that block immune inhibitory receptors (checkpoint blockade.

A recent meta-analysis reported that tumor-infiltrating CD8+ lymphocytes can be identified in 48% of all breast cancers .Interestingly, triple-negative breast cancers show the highest incidence of lymphocyte predominance. Moreover, TILs were found to be prognostic in triple-negative breast cancer, and higher levels of TILs were predictive for trastuzumab benefit in HER2+ disease. These findings suggest that therapies that enforce immune responses could potentially improve patient survival.

Inclusion Criteria:

• Female patients admitted at South Egypt cancer institute who diagnosed as breast cancer based on full clinical, radiologic and pathologic assays

Exclusion Criteria:

1. Patients receive any anti-cancer therapy.
2. Patients diagnosed with other concomitante cancer or chronic disease

female

Female patients admitted at South Egypt cancer institute who diagnosed as breast cancer based on full clinical, radiologic and pathologic assays