Fig. 6.
Lyme carditis in CD11b-deficient mice involves increased inflammation and deficient control of B. burgdorferi. CD11b-deficient and wild-type controls were infected with 1 × 105 spirochetes by s.c. injection in the midline of the back. (A and B) After being euthanized, the mice were analyzed histologically for signs of arthritis (B) and carditis (A and B). *Student's t test, P < 0.05. n = 11 in each group. (C) Percentages of hearts positive for B. burgdorferi recA targets by qPCR. *χ2, P < 0.05. n = 16 in each group. (D) The levels of tnf gene expression in the hearts of the infected mice were analyzed by qRT-PCR relative to actin levels. *Student's t test, P < 0.05. n = 11 in each group. The results represent two to three independent experiments with 5–6 mice per group. (E) TNF production by B6 and CD11b-deficient BMMs in response to B. burgdorferi stimulation. BMMs were stimulated with live spirochetes at increasing m.o.i. for 16 h, followed by the analysis of the stimulation supernatants for TNF by ELISA.