Introduction
The progression of lung cancer is known to be linked with an overall weakened antitumor immunity[1] . Therefore, novel approaches for its treatment have been developed with the key objective of inhibiting this attenuated immune mechanism on one hand and activating self-defense [2] . Tremendous progress has been made to unveil the mechanism of the immune cell defense against cancer cells, presenting new and promising therapies based on new immunotherapy, represented in Immune checkpoint inhibitors, Antigen-specific vaccines and Adoptive T cell transfer (CAR T-cell), which augment the immune system in targeting cancer cells [3] . These promising methods can potentially provide long term cancer remission without causing the same side effects evident when using chemotherapeutic agents and radiation. In addition, they hold great promise in improving the prognostic outcomes of lung cancer patients, overcoming the hurdle of the poor overall 5-year survival rate barely ranging between 5-15% [4].
Lung cancer cells elicit an immune response that recruits cytolytic immune cells including cytotoxic T cells (CD8+) and natural killer cells (NK). These cells are able to remove harmful cells via the release of the cytolytic content of their granules such as perforin(Pr), granzymes (Gzs) and interferon-gamma (IFN-γ) into the cytosol of targeted cells ultimately leading to decomposing these cells[5] . Granzymes have the ability to target cells promoting downstream caspase activation and cell death. However, out of this serine protease granzyme family, Granzyme B (GzB) poses the major constituent excreted by CD8+ and NK and holds the strongest apoptotic activity of all Gzs [6] . Therefore, the ability of cancer cells to resist these cytolytic mediators plays a vital role in their continued existence and expansion.
Addressing the functionality of immune cells is of major importance to enable the evolvement of more effective immunotherapeutic approaches. Previous studies have demonstrated that lung cancer is associated with a locally decreased expression of GzB, Pr and IFN-γ by the tumor-infiltrating CD8+ T cells, NK and NK T like cells in the tumor microenvironment by the effect of lung cancer mediators like prostaglandin E2 (PGE2), transforming growth factor (TGF)-β) which have a relationship with assisting tumor cell proliferation, anti-apoptotic properties, angiogenesis and chemotherapeutic resistance [7, 8] . These alterations within the tumor microenvironment were found to impair the functionality of these cells and reduce the effectiveness of the adaptive immune responses against cancer cells. Accordingly, the hypothesis that this dysfunction extends beyond the confined boundaries of the tumor microenvironment has been validated [9] . we conducted the previous study concluded that the numbers of CTLs and NK cells and their expression of GzB were reduced in newly diagnosed lung cancer patients[10] .
In This study, we aim to address the number and functionality of CD4, CD8, NK, NKCD4 and NKCD8T cell in lung cancer patients before, during and after induction of chemotherapy and their intracellular expressions of GzB versus the inflammatory and prognosis cytokines and interleukins correlates it with the clinical response of patients in order to activation conditions with Concanavalin A (Con A) and Interleukin-2 (IL-2) in certain settings of culture in-vitro .