Multiple types of immune cells are interspersed among the epithelial cells lining the intestines and are considered to be a first line of defense against pathogens. The survival and interaction of these intraepithelial lymphocytes and their roles in intestinal inflammation are not well understood.

Ali Nazmi, PhD, Danyvid Olivares-Villagómez, PhD, and colleagues have examined the effect of one type of intraepithelial lymphocyte (iCD8alpha) on another (ILC1-like). Using mice with reduced numbers of iCD8alpha cells, they found that these cells play a critical role in the survival of ILC1-like cells, and that this effect is partly mediated by the factor osteopontin.

In a mouse model of intestinal inflammation that involves ILC1-like cells, reduced iCD8alpha cell numbers resulted in milder inflammation and treatment with osteopontin increased disease severity.

The findings, reported in PLOS ONE, implicate iCD8alpha cells in ILC1-like cell survival and intestinal inflammation and add to the growing roles of osteopontin in various biological processes.

This research was supported by the National Institutes of Health (grants DK111671, LM000745) and by the American Association of Immunologists.