Fig. 5

IgG-producing plasma-like B cells exert a different effect on tumor cells in different stages of lung cancer. a IgG-producing plasma-like B cells isolated from patient at stage III lung cancers promote proliferation of A549 cells. The left panel shows a schematic of the experiment design. CD20⁻BCMA⁺ B cells isolated from stage I or stage III lung tumors were co-cultured with A549 cells, and the cell growth was determined by CCK8 assays (right panel). b The function of CD20⁻BCMA⁺ B cells on A549 cells was exerted in a cell-cell interaction-independent manner. The left panel showed a schematic of the experiment design. The culture supernatant of the CD20⁻BCMA ⁺ B cells isolated from stage I or stage III lung tumors was used to treat A549 cells, and the cell growth was determined by CCK8 assays (right panel). c The level of IgG produced by plasma-like B cells had no significant difference between stage I and stage III. The amount of IgG was determined by ELISA experiments. d The pathology IgG in stage I and stage III exerts different functions on A549 cells. The left panel showed a schematic of the experiment design. The purified IgG was validated by western blot using antibodies against the human IgG (right panel). e The pathology IgG isolated from stage III NSCLC but not stage I promoted the cell growth of A549 cells