Figure 3.

Absence of SIGN-R1 increases susceptibility to pneumococcal peritonitis. (a) Survival after S. pneumoniae type 2 infection. SIGN-R1^−/− mice (n = 12) or control mice (n = 12) were inoculated intraperitoneally with 10³ S. pneumoniae type 2. SIGN-R1^−/− have reduced survival (P = 0.005). The experiment shown is representative of two, and p-values were obtained using a Log rank test. (b and c) Physical signs of illness in mice with pneumococcal peritonitis. After inoculation with S. pneumoniae (type 2), mice were monitored by a blinded observer for the signs of systemic illness. The presence or absence of piloerection (1 point), with additional hunched posture (2 points), and lack of spontaneous movement (3 points) was scored in control and SIGN-R1^−/− mice inoculated with 10³ S. pneumoniae at 24 h (b) and 30 h (c). The experiment is representative of two. (d) 30 h after inoculation with S. pneumoniae, tail bleeds were performed on control (n = 12) and SIGN-R1^−/− mice (n = 10), and blood was cultured for bacterial growth. More SIGN-R1^−/− mice were bacteremic (P = 0.014); the p-value was obtained using a Fisher's exact test. (e) Survival after S. pneumoniae type 14 infection. SIGN-R1^−/− mice (n = 10) or control mice (n = 10) were inoculated intraperioneally with 10⁵ S. pneumoniae type 14. SIGN-R1^−/− have reduced survival (P = 0.018). Numbers denote individual mice. p-values were obtained using a Log rank test. (f and g) Physical signs of illness in mice with pneumococcal peritonitis. After inoculation with S. pneumoniae (type 14), mice were monitored by a blinded observer for the signs of systemic illness (as described before). (h) 26 h after inoculation with S. pneumoniae, tail bleeds were performed on control (n = 10) and SIGN-R1^−/− mice (n = 10), and blood was cultured for bacterial growth. More SIGN-R1^−/− mice were bacteremic (P = 0.023).