Figure 2.

Identification of a novel antigen recognized by LKAb. A) Both commercial anti-CTSG antibody and LKAb bound to a 28 kDa protein in Western blots of lysates from cells overexpressing CTSG. B) Lysates of mouse bone marrow cells were incubated with LKAb for immunopurification. Eluates from these immune complexes bound to the commercial anti-CTSG antibody in Western blots. C) A CTSG enzymatic assay showed that CTSG enzyme activity was present in the eluates and mouse bone marrow total lysates. D) Mouse bone marrow was incubated for 2 d with lentiviruses containing CTSG shRNA, followed by incubation with LKAb (10 μg/ml) or M-CSF (10 ng/ml) for 6 d. The cells were then stained with anti-CD11b and anti-F4/80. FACS analysis showed that the induced macrophage populations were dramatically reduced when CTSG mRNA was silenced. However, M-CSF still induced macrophages when CTSG mRNA was silenced. Right: percentage of macrophages. *P < 0.05; Student’s t test.