In an attempt to correlate host and parasite-related events occurring during the course of a primary Giardia infection in the mouse we have measured epithelial cell kinetics, enzymes, and intraepithelial lymphocytes at different stages of the infection. New methods were developed for the accurate measurement of parasite numbers and distribution within the gut. In jejunum a modest decrease in vi...

Murine gut intraepithelial (IEL) T cell receptor (TCR)-alpha/beta lymphocytes bearing CD8alpha/13 or CD8alpha/alpha coreceptors have been shown previously to express different oligoclonal TCR beta chain repertoires in the same mouse, in agreement with other evidence indicating that these two populations belong to different ontogenic lineages, with only CD8alpha/beta+ IELs being fully thymus dep...

It is clear from experimental studies in mice that T cell maturation can occur outside the thymus, especially in the intestine. There is little sound evidence so far that extrathymic T cell maturation occurs to any significant extent in human gut, and, postnatally, there is abundant evidence that the gut mucosa is an immune effector organ. Here, we describe a large population of T lymphocytes i...

The gastrointestinal tract forms the largest surface in our body with constantly being exposed to various antigens, which provides unique microenvironment for the immune system in the intestine. Accordingly, the gut epithelium harbors the most T lymphocytes in the body as intraepithelial lymphocytes (IELs), which are phenotypically and functionally heterogeneous populations, distinct from the c...

Ways of accelerating recovery of the mucous membrane immune system in lethally irradiated mice following syngeneic bone marrow transplantation were studied over a 35-day period by quantification of jejunal intraepithelial lymphocytes (lEis) and lamina propria plasma cells. Recovery after a low bone marrow dose allowing 1 00% animal survival (IBM) was compared with a high (five times minimal) do...

iii Populärvetenskaplig sammanfattning på svenska v Abbreviations list viii List of papers in the thesis ix 1 Introduction 1 1.1 General overview of the immune system 1 1.2 Lymphocytes 2 1.2.1 B-lymphocytes 2 1.2.2 T-lymphocytes 2 1.2.2.1 Extrathymic T-cell maturation 4 1.2.3 T-helper cells 5 1.2.4 Regulatory T-cells 6 1.2.5 Natural killer T-cells 7 1.2.6 γδT-cells 7 1.2.7 Cytotoxic ...

The gut environment has been found to significantly influence autoimmune diseases such as multiple sclerosis; however, immune cell mechanisms are unclear. Here we show that the gut epithelium of myelin oligodendrocyte glycoprotein(35-55)-specific T-cell receptor transgenic mice contains environmental stimuli-induced intraepithelial lymphocytes (IELs) that inhibit experimental autoimmune encepha...