Mesenteric lymph nodes

About: Mesenteric lymph nodes is a research topic. Over the lifetime, 2839 publications have been published within this topic receiving 94439 citations. The topic is also known as: mesenteric lymph node & mesenteric glands.

Cutting edge: cure of colitis by CD4+CD25+ regulatory T cells.

Abstract: CD4(+)CD25(+) regulatory T cells have been shown to prevent T cell-mediated immune pathology; however, their ability to ameliorate established inflammation has not been tested. Using the CD4(+)CD45RB(high) T cell transfer model of inflammatory bowel disease, we show that CD4(+)CD25(+) but not CD4(+)CD25(-)CD45RB(low) T cells are able to cure intestinal inflammation. Transfer of CD4(+)CD25(+) T cells into mice with colitis led to resolution of the lamina propria infiltrate in the intestine and reappearance of normal intestinal architecture. CD4(+)CD25(+) T cells were found to proliferate in the mesenteric lymph nodes and inflamed colon. They were located between clusters of CD11c(+) cells and pathogenic T cells and found to be in contact with both cell types. These studies suggest that manipulation of CD4(+)CD25(+) T cells may be beneficial in the treatment of chronic inflammatory diseases.

A Discrete Subpopulation of Dendritic Cells Transports Apoptotic Intestinal Epithelial Cells to T Cell Areas of Mesenteric Lymph Nodes

Abstract: This study identifies a dendritic cell (DC) subset that constitutively transports apoptotic intestinal epithelial cell remnants to T cell areas of mesenteric lymph nodes in vivo. Rat intestinal lymph contains two DC populations. Both populations have typical DC morphology, are major histocompatibility complex class IIhi, and express OX62, CD11c, and B7. CD4+/OX41+ DCs are strong antigen-presenting cells (APCs). CD4−/OX41− DCs are weak APCs and contain cytoplasmic apoptotic DNA, epithelial cell–restricted cytokeratins, and nonspecific esterase (NSE)+ inclusions, not seen in OX41+ DCs. Identical patterns of NSE electrophoretic variants exist in CD4−/OX41− DCs, intestinal epithelial cells, and mesenteric node DCs but not in other DC populations, macrophages, or tissues. Terminal deoxynucleotidyl transferase–mediated dUTP-biotin nick-end labeling (TUNEL)-positive DCs and strongly NSE+ DCs are present in intestinal lamina propria. Peyer's patches and mesenteric but not other lymph nodes contain many strongly NSE+ DCs in interfollicular and T cell areas. Similar DCs are seen in the ileum and in T cell areas of mesenteric nodes in gnotobiotic rats. These results show that a distinct DC subset constitutively endocytoses and transports apoptotic cells to T cell areas and suggest a role for these DCs in inducing and maintaining peripheral self-tolerance.

Pretreatment of Mice with Streptomycin Provides a Salmonella enterica Serovar Typhimurium Colitis Model That Allows Analysis of Both Pathogen and Host

Abstract: Salmonella enterica subspecies 1 serovar Typhimurium is a principal cause of human enterocolitis. For unknown reasons, in mice serovar Typhimurium does not provoke intestinal inflammation but rather targets the gut-associated lymphatic tissues and causes a systemic typhoid-like infection. The lack of a suitable murine model has limited the analysis of the pathogenetic mechanisms of intestinal salmonellosis. We describe here how streptomycin-pretreated mice provide a mouse model for serovar Typhimurium colitis. Serovar Typhimurium colitis in streptomycin-pretreated mice resembles many aspects of the human infection, including epithelial ulceration, edema, induction of intercellular adhesion molecule 1, and massive infiltration of PMN/CD18(+) cells. This pathology is strongly dependent on protein translocation via the serovar Typhimurium SPI1 type III secretion system. Using a lymphotoxin beta-receptor knockout mouse strain that lacks all lymph nodes and organized gut-associated lymphatic tissues, we demonstrate that Peyer's patches and mesenteric lymph nodes are dispensable for the initiation of murine serovar Typhimurium colitis. Our results demonstrate that streptomycin-pretreated mice offer a unique infection model that allows for the first time to use mutants of both the pathogen and the host to study the molecular mechanisms of enteric salmonellosis.

Translocation of Certain Indigenous Bacteria from the Gastrointestinal Tract to the Mesenteric Lymph Nodes and Other Organs in a Gnotobiotic Mouse Model

Abstract: Viable bacteria were not cultured from the mesenteric lymph nodes, spleens, or livers of specific-pathogen-free (SPF) mice. Viable enteric bacteria, primarily indigenous Escherichia coli and lactobacilli, were present in the mesenteric lymph nodes of gnotobiotic mice inoculated intragastrically with the whole cecal microflora from SPF mice but not in the nodes of control SPF mice similarly inoculated. These indigenous E. coli also were cultured from the mesenteric lymph nodes of 96% of gnotobiotic mice monoassociated with E. coli but from none of the mesenteric lymph nodes of SPF mice inoculated with the E. coli. Furthermore, viable E. coli were detected in the mesenteric lymph nodes of these monoassociated gnotobiotes for as long as 112 days after inoculation. Indigenous Lactobacillus acidophilus also translocated to the mesenteric lymph nodes of gnotobiotic mice monoassociated with L. acidophilus. Apparently, there are mechanisms active in SPF mice inhibiting translocation of indigenous bacteria from the gastrointestinal tract to the mesenteric lymph nodes, spleens, and livers, whereas these mechanisms are either absent or reduced in gnotobiotic mice. Indigenous E. coli maintained higher population levels in the gastrointestinal tracts of the gnotobiotes compared with their population levels in SPF mice, suggesting that high bacterial population levels might promote translocation of certain bacteria from the gastrointestinal lumen to the mesenteric lymph nodes. Gnotobiotic and SPF mice, therefore, provide experimental models for determining the nature of the mechanisms operating to confine indigenous bacteria to the gastrointestinal tract in normal, healthy animals.

Total parenteral nutrition promotes bacterial translocation from the gut.

Abstract: Bacterial translocation from the gut may be the primary event in many disease processes. The purpose of this study was to examine the route of nutrient administration on bacterial translocation from the gut. Each of 90 female Fischer rats underwent placement of a central venous catheter and was randomized to one of three groups. Group I (control) received food and water ad libitum. Group II received standard TPN solution orally from a bottle sipper and drank the solution ad libitum. Group III underwent TPN via the central catheter by pair feeding of the animals with group II. Animals were fed for 2 weeks, and liver, spleen, mesenteric lymph nodes, blood, and cecum were aseptically obtained for culture. A statistically significant difference (p less than 0.014) was found between translocation rates of parenterally fed animals compared with enterally fed animals. Two thirds of the animals (18/27) fed parenterally had culture-positive mesenteric lymph nodes compared with one third (9/27) of the enterally fed group and none (0/30) of the control group. A statistically significant increase in the cecal bacterial count was demonstrated in the animals fed the TPN solution, independent of route. Parenteral nutrition promotes bacterial translocation from the gut by increasing the cecal bacterial count and impairing intestinal defense.