FIG. 1.
Endogenous TNF-α is a key positive regulator of the in vivo anti-PspA, anti-PsaA and, to a lesser extent, anti-PC response to R36A. Mice were injected i.p. with 0.5 mg of anti-TNF-α MAb (XT22) or the same amount of control rat IgG1 MAb (GL113) or saline. Twenty-four hours later mice were injected i.p. with R36A (2 × 108 CFU/mouse). Sera were collected 1 week after primary immunization with R36A for determination of anti-PC titers and 2 weeks after immunization for determination of anti-PspA and anti-PsaA titers by ELISA. Values represent arithmetic means ± SEM of eight mice per group. *, P < 0.05. Data are representative of three similar experiments.