Striking phenotypic and functional differences in lamina propria lymphocytes from the large and small intestine of mice

Although intraepithelial T lymphocytes of the large intestine (LI) are known to differ from those of the small intestine (SI) in phenotype and function.. differences in LI and SI lamina propria (LP) lymphocyte populations have not been clearly established. In this work we found striking phenotypic differences between SI and LI LP lymphocyte populations from Balb/c mice analyzed by flow cytometry. In the LI most lymphocytes were B cells and the predominant T cells were TCR-(alpha beta(+), CD8(+). In contrast, in the SI most T lymphocytes were CD4(+) expressing TCR-alpha beta(+), although a higher proportion expressed TCR-gamma delta(+) than in the U. In T cells the expression of adhesion molecules and cytokines was also different between SI and LT. The proportion of LP T cells expressing alpha(4)beta(7) and L-selectin was higher in the LI than in the SI; whereas a greater proportion of cells expressing alpha(E)beta(7) were detected in the SI than in LT. Higher proportions of T cells expressing L-selectin and alpha(4)beta(1) were detected in the intraepithelial compartment of the LI than that of the SI, whereas the number of T cells expressing alpha(E)beta(7) was much higher in the SI than in the LT. The proportion of T cells spontaneously producing IL-2, IFN gamma, and IL-4 at the intraepithelial and lamina propria, in the small and large intestine, was different indicating that distinctive functional features exist in the lymphocyte populations residing at the different intestinal compartments. (c) 2005 Elsevier Inc. All rights reserved.