Ontogeny of intestinal epithelium immune function: developmental events and environmental modulation

RUMBO M. AND SCHIFFRIN E

CELLULAR AND MOLECULAR LIFE SCIENCES

Año: 2005 vol. 62 p. 1288 - 1296

1420-682X

Intestinal mucosa integrates primary digestive functions with immune functions like pathogen surveillance, antigen transport and induction of mucosal immunity and tolerance. Intestinal adaptive immunity is achieved by mucosa-associated lymphoid tissue (MALT) that combines organized aggregates constituted of antigen-presenting cells and lymphocytes (O-MALT) and widespread distributed effector cells (diffuse or D-MALT). Interaction between intestinal epithelium and O-MALT and D-MALT play a critical role to establish an adequate immune response. In regions associated to O-MALT, lympho-epithelial cross-talks lead to acquisition of specific epithelial phenotype that contribute to O-MALT organization and functionality. Beyond the expression of several innate immune functions, intestinal epithelium may directly take up and present antigens due to the expression of major histocompatibility complex (MHC) and MHC-related molecules. Immune functions of intestinal epithelium are developmentally controlled by a complex genetic program that will be outlined in the present review. The effect of environmental signals on the modulation of this ontogenetic program during development and neonatal life, from bioactive components of amniotic fluid to lactation and bacterial colonization, will be discussed.