B lymphocytes
B lymphocytes (B cells) are an important part of the human adaptive
immune response and humoral immune response. Studies have found that B
cells play an important role in anti-tumor immune response[84].
According to the analysis of the TCGA database, tumor infiltrating B
cells (TIB) abundance is significantly higher in the NSCLC with EGFR
mutation[85]. Studies have found that B cells usually existed in a
tissue called tertiary lymphoid structure (TLS), and TLS was associated
with a good prognosis[86]. The main function of B cells is humoral
immune response, in lung tissue, B cells differentiate into plasma
cells, which produce specific antibodies and recognize tumor associated
antigens[86, 87]. In addition, activated TIB can activate tumor
infiltrating T cells (TIT) through presenting tumor antigen to TIT and
activating the anti-tumor effect of TIT[88]. However, regulatory B
cell (Breg), a subtype of B cells, can inhibit immunity and promote
tumor proliferation and metastasis[89]. It has been found that Breg
can weaken the response of T cells and NK cells and facilitate the
immune suppressive activity of regulatory T cells (Treg) by
up-regulating immune regulatory ligands through secreting
immunosuppressive factors such as IL-10, TGF-β[90]. Therefore, the
relationship between B cells and EGFR-TKIs is complicated and needs
further study.