Figure 3.

Osteopontin promotes in vitro IEL survival. (A) Indicated FACS-enriched IEL populations from WT mice were left untreated or treated with recombinant murine osteopontin (rOPN; 2 μg/ml), with or without anti-mouse CD44 (5 μg/ml). After the indicated time points, cell survival was determined. Data are representative of three independent experiments. Biological replicas consisted of two to three pooled IEL preparations from individual mice; each experiment consisted of 3 biological replicas. (B) Enriched CD45⁺ splenocytes were treated as in (A). Data are representative of two independent experiments (n = 3). (C) FACS-enriched TCRβ⁺CD44⁺ spleen cells from WT and Spp-1^−/− mice were treated as in (A). Data are representative of two independent experiments (n = 3). (D) Neonatal human IEL were incubated in the presence or absence of recombinant human osteopontin (2 μg/ml) and anti-human CD44 (5μg/ml). After the indicated time points, cell survival was determined. Each symbol represents an individual human: circle, small intestine from 1-day old patient presenting volvulus and necrosis; square, ileum and colon from 17-day old patient presenting necrotizing enterocolitis; triangle, jejunum from 12-day old patient presenting necrotizing enterocolitis; diamond and hexagon, de-identified individuals. (E) PBMC from adult humans were treated as in (D). Data are representative of two independent experiments (n = 3). *P<0.05, **P<0.01, ***P<0.001 (One-way ANOVA).