Figure 5.

M. tb Rv1507A protein elicits IgG response in immunized mice and exhibits immunoreactivity in sera of Tuberculosis patient. BALB/c mice were immunized with either purified M. tb Rv1507A protein or infected with Rv1507A knock-in M. smegmatis (Ms_Rv1507A) and control M. smegmatis (Ms_Vc). The level of IgG in the mouse sera was tested using ELISA and measured spectrophotometrically (492nm) (A). Sera were collected from pulmonary TB patients (n = 31) or control volunteers (n = 19). Immunoreactivity of human sera against Rv1507A was tested as described in methods and measured spectrophotometrically (450 nm) (B). Receiver operating characteristics (ROC) curve to assess the cut-off value of ELISA depicting % sensitivity and % specificity (C). Data are shown as mean ± SEM. Statistical significance was determined with one tailed Mann–Whitney test. p < 0.05 was considered significant. **p < 0.01, ****p < 0.0001.