CHARACTERISTIC OF LYMPHOID TISSUE ASSOCIATED WITH THE INTESTIN OF WHITE RATS

Intestinal lymphoid tissue plays an important role in the presentation of antigens to immunocompetent cells and participation in the subsequent immune response. The elements of the system are dynamic, they form and disappear depending on the presence of stress factors of various nature. The article presents the parameters of intestinal lymphoid tissue in clinically healthy rats.

Spatial distribution of LTi-like cells in intestinal mucosa regulates type 3 innate immunity

Lymphoid tissue inducer (LTi)-like cells are tissue resident innate lymphocytes that rapidly secrete cytokines that promote gut epithelial integrity and protect against extracellular bacterial infections.Here, we report that the retention of LTi-like cells in conventional solitary intestinal lymphoid tissue (SILT) is essential for controlling LTi-like cell function and is maintained by expression of the chemokine receptor CXCR5. Deletion of Cxcr5 functionally unleashed LTi-like cells in a cell intrinsic manner, leading to uncontrolled IL-17 and IL-22 production. The elevated production of IL-22 in Cxcr5-deficient mice improved gut barrier integrity and protected mice during infection with the opportunistic pathogen Clostridium difficile. Interestingly, Cxcr5−/− mice developed LTi-like cell aggregates that were displaced from their typical niche at the intestinal crypt, and LTi-like cell hyperresponsiveness was associated with the local formation of this unconventional SILT. Thus, LTi-like cell positioning within mucosa controls their activity via niche-specific signals that temper cytokine production during homeostasis.

Influence of subalin probiotic on Blue Frost fox intestinal lymphoid tissue formation

For research, Blue Frost fox puppies were used at the age of 2 months. 2 groups of animals of 30 heads in each group were formed by the analog method. The experimental animal group received subalin courses with the basic diet according to the scheme: 5 days of probiotic in the amount of 10 - 20 * 107 CFU/kg, for two months in courses with 10 days break, only 4 courses.

Anatomically remote education of B cells is required for colonic health

Mucosa-associated lymphoid tissues contain roughly 80% of all immune cells and produce virtually all of the body’s IgA1–3. Although the majority of IgA-secreting cells educated within a mucosal site home back to the same anatomic region, some cells are also found in distant mucosal tissues2–6. These observations underlie the notion of a common mucosal immune system, which holds that anatomically unrelated mucosal sites are functionally connected by a shared immune system2,3. However, the ontological basis of this separation between site of immune education and functionality has remained elusive. Here we show that mice lacking Peyer’s patches (PPs)—small-intestinal lymphoid tissue covered by antigen-sampling M cells—have no immunologic defect in the small-intestinal lamina propria. Surprisingly, the primary immunological abnormality in PP-deficient mice was a reduction in colonic B cells, including plasmablasts but not plasma cells. Adoptive transfer experiments conclusively demonstrated that PP-derived cells preferentially give rise to colonic—but not small-intestinal—B cells and plasmablasts. Finally, these PP-derived colonic B cells were critical for restraining colonic inflammation. Thus, PPs bridge the small-intestinal and colonic immune systems and provide a clear example of immune education being required in an anatomic compartment distinct from the effector site. Our findings, which highlight that the majority of fecal IgA is produced by colonic plasmablasts that originate from PPs, will help inform design of mucosal vaccines.