Factors Affecting the Lymphoid Cells in the Small Intestinal Epithelium of the Mouse

Abstract

The ontogeny of the lymphoid cells in conventional and germ-free mice has been studied. Development is similar in both groups up to the age of 4 weeks. During the first 2 weeks of neonatal life, few cells are present, but the numbers increase rapidly between 2 and 4 weeks of age. The number of cells continues to increase in conventional mice, but remains static in germ-free mice. Exposing adult germ-free mice to a conventional environment results in an increase in the size of the epithelial lymphocyte population to that characteristic of conventional mice. Rearing conventional weanling mice on antibiotic-treated drinking water does not prevent the post-weaning increase in lymphoid cell numbers. The results are interpreted as showing that the lymphoid cell population in the intestinal epithelium is part of the second-level or peripheral lymphoid tissue rather than part of the first-level systems such as the thymus and bursa of Fabricius.

Enteric Flora Expands Gut Lamina Propria CX3CR1+ Dendritic Cells Supporting Inflammatory Immune Responses under Normal and Inflammatory Conditions

“…Axenic animals are characterized by more slender and shorter ileal villi compared with SPF animals (43) in which CX 3 CR1 + DCs are located. Intestinal villi of GF mice are more uniform compared with SPF animals (44).…”

Intraepithelial lymphocytes of human gut: isolation, characterisation and study of natural killer activity.

“…That they may participate in the mucosal immune defence is suggested by low number in germ free animals,1 12 and the frequency of digestive diseases in T-immunodeficient patients.13 They are increased in several enteropathies such as coeliac disease,7 14 cow's milk intolerance, 15 and in graft-versus-host disease, where some evidence suggests their involvement in a cellular reaction responsible for epithelial damage. 16 17 Recently, their morphological similarity with the peripheral blood large granular lymphocytes that mediate natural killer activity18 has suggested that intraepithelial lymphocytes may be natural killer cells.…”

Intraepithelial lymphocytes in the jejunal mucosa of malnourished rats.

“…One possible explanation for their location would be that the intestinal epithelium is an important site on the migration pathways of young T cells, perhaps because of the large amounts of antigen which may be present in the intestinal lumen (Ferguson, 1977). Although data on antigen excess, either microbial or alimentary, are not available, it is known that germ-free animals deprived of microbial antigens have low IEL counts (Glaister, 1973;Ecknauer and Lohrs, 1976) and that removal of food antigen from healthy animals does not induce a decrease of IEL counts (Ferguson, 1976); on the other hand, it is suggested that the increase of IEL counts in coeliac disease must be due to antigen stimulation (Mavromichalis et al, 1976). It might be hypothesised, therefore, that an increase of intestinal IEL could be occurring in malnutrition, in which intestinal infection, bacterial overgrowth in the small bowel, or partial digestion of food protein antigens is likely to occur.…”