CD244 and tuberculosis: Addition of anti-human CD244/2B4 monoclonal antibody clone eBioPP35 to the culture medium of human PBMCs from patients with active TB during M. tuberculosis antigen stimulation resulted in significantly higher frequencies of IFN-γ-producing CD4+ T cells (p = 0.0015) (Fig. 5A and 5B) and increased production of IFN-γ (p = 0.0018) (Fig. 5A and 5C) and also elevated numbers of SFU in ELISPOT assay (p = 0.0024) (Fig. 5D), compared with isotype antibody controls.