Adaptive immunity does not contribute to neonatal sepsis survival. Kaplan-Meier sepsis survival curves. (A) Sepsis survival in C57BL/6 and RAG-1–deficient adult mice following administration of cecal slurry (1 mg/g LD₁₀). Adult sepsis survival in RAG-1–null mice (■) was significantly less (36%; P < .05 by Fisher exact test) than C57BL/6 wild-type adults (□; 100%). (B) Sepsis survival in C57BL/6 and RAG-1–deficient neonatal mice following administration of cecal slurry (1.3 mg/g LD₇₀). Neonatal sepsis survival was not statistically different in C57BL/6 wild-type (♦) or RAG-1–deficient (◇) mice. (C) Sepsis survival in wild-type C57BL/6 neonates following anti-GITR (■) or isotype control (□) pretreatment followed by administration of cecal slurry (1.3 mg/g LD₇₀). Neonatal sepsis survival was not statistically different in anti-GITR (■) or isotype control (□) pretreatment groups.