Morphohistology and Biometric Characteristics of Cecal Tonsils of Sonali Chicken at Post-Hatching Ages

Knowledge of basic structures is prerequisite for acquiring an in-depth idea about the physiology and immunology of the lymphoid system. The study evaluates the age related histomorphometry of cecal tonsil of Sonali chicken at different postnatal stages in Bangladesh as literatures regarding this are very scarce. The investigation was carried out on 25 healthy Sonali chickens representing different stage of postnatal life: days 1, 14, 28, 42, and 56 (n=5). After ethically sacrifice (cervical subluxation method), cecal tonsil was collected and subjected for both gross and histological studies. Haematoxylin and Eosin stain was done for microscopic study. Morphologically, cecal tonsils were located bilaterally at the junction of small and large intestine. It had tubular structure and yellowish white in color. All gross parameters (weight, length, and width) found to be increased significantly (P<0.05) throughout the whole study period. Weight was measured 0.022±0.001 g at day 1 and noticed 0.181±0.016 g at the end of study tenure. The microscopic observations revealed that at day 28 encapsulated lymphatic nodules was present along with the diffuse lymphocytes at the lamina propria and submucosa layer, which was absent at the previous study groups. At day 1, only small infiltration of lymphocytes was identified and at day 14, lymphocytes were aggregating to form lymphatic nodules. After that, age related development was noticed in histological features. The findings would be a milestone to give an idea about the gut health and immune status of Sonali chicken and provide a basis for further immunization research.

Macroscopic assessment of protective effect of cryopreserved placenta extract in ibuprofen-induced gastroenterocolonopathy

Background. Over-the-counter use of nonsteroidal anti-inflammatory drugs leads to their uncontrolled consumption among the population, which in some cases makes it impossible to prevent and timely detect adverse drug effects, and their effectiveness does not always satisfy clinicians. The purpose was to characterize the cytoprotective properties of cryopreserved placenta extract according to the condition of the mucous membrane of the proximal (esophagus and stomach) and distal (small and large intestine) parts of the gastrointestinal tract on the model of ibuprofen-induced esophagogastroenterocolonopathy. Mate­rials and methods. In vivo experimental studies were performed on 28 male rats. Subchronic ibuprofen-induced gastrointestinal lesions were reproduced by intragastric administration of ibuprofen to rats at a dose of 310 mg/kg. The condition of the gastrointestinal tract mucous membrane was assessed macroscopically on a scale. Results. The therapeutic and prophylactic efficacy of esomeprazole statistically significantly (р < 0.05) took place in the proximal parts of the gastrointestinal tract but had little effect on the prevalence of ulcerative lesions in the intestine. At the same time, unlike esomeprazole, which is known to have only gastroprotective activity, cryopreserved placenta extract had a cytoprotective effect both in the stomach and in the distal parts of the gastrointestinal tract — small and large intestine. Thus, the prevalence of ibuprofen-induced both entero- and colonopathy on the background of the study of the extract was almost twice lower than in rats that did not receive correction drugs. Conclusions. It is established that the use of cryopreserved placenta extract in the treatment-and-prophylactic mode has comparable to esomeprazole gastroprotective activity. In addition, it was found that the use of the studied cryoextract was accompanied by a decrease in the multiplicity of ulcerative defects in the small and large intestine of rats, by 4.6 and 3.8 times, respectively, compared to the control animals.

The small and large intestine contain transcriptionally related mesenchymal stromal cell subsets that derive from embryonic Gli1+ mesothelial cells

Intestinal fibroblasts (FB) play essential roles in intestinal homeostasis. Here we show that the small and large intestinal lamina propria (LP) contain similar FB subsets that locate in specific anatomical niches and express distinct arrays of epithelial support genes. However, there were tissue specific differences in the transcriptional profile of intestinal FB subsets in the two sites. All adult intestinal LP mesenchymal stromal cells (MSC), including FB, smooth muscle cells (SMC) and pericytes derive from Gli1-expressing embryonic precursors which we identify as mesothelial cells. Trajectory analysis suggested that adult SMC and FB derive from distinct embryonic intermediates, and that adult FB subsets develop in a linear trajectory from CD81+ FB. Finally, we show that colonic subepithelial PDGFRαhi FB comprise several functionally and anatomically distinct populations that originate from an Fgfr2-expressing FB intermediate. Collectively our results provide novel insights into MSC diversity, location, function and ontogeny, with implications for our understanding of intestinal development, homeostasis and disease.

Electromagnetic Fields Modify Redox Balance in the Rat Gastrointestinal Tract

Objective: The aim of the study was to assess the influence of electromagnetic fields with divergent physical properties on the prooxidative and antioxidative balances in homogenates of the tongue, salivary glands, esophagus, stomach, and small and large intestines of rats.Material and Methods: Forty rats were randomly divided into four equal groups, namely, a control group, a group exposed to low-frequency electromagnetic fields (LF-EMFs; frequency: 50 Hz; intensity: 10 kV/m; magnetic induction: 4.3 pT), a group exposed to radiofrequency electromagnetic fields (RF-EMFs) emitted by mobile phones (frequency: 900 MHz), and a group exposed simultaneously to LF-EMFs and RF-EMFs emitted by mobile phones. After 28 consecutive days of the experiment, the following pro- and antioxidative markers were assessed in the gastrointestinal tract homogenates: superoxide dismutase (SOD) and its two isoenzymes (Mn-SOD, Cu,Zn-SOD) catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), total antioxidative capacity (TAC), total oxidative status (TOS), and malondialdehyde (MDA).Results: In rats exposed to LF-EMFs, higher concentrations of the markers of prooxidant processes, MDA or TOS, were observed in the salivary glands, esophagus, and small intestine homogenates in comparison with the control group. Additionally, in the group of rats opposite to the control, antioxidant activity was observed. The main differences included a higher activity of Cu,Zn-SOD in homogenates of the tongue, salivary glands, and esophagus as well as decreased activity of CAT in homogenates of the tongue, esophagus, and small intestine. In animals exposed to RF-EMFs, the concentration of TOS was higher in the large intestine than in control rats. The main difference of antioxidant activity was presented by decreased Cu,Zn-SOD in homogenates of the salivary glands, stomach, small and large intestine as well as CAT in homogenates of the tongue, esophagus, stomach, and small and large intestine. Moreover, in rats exposed simultaneously to LF-EMFs and RF-EMFs, a lower concentration of TOS was observed. Antioxidant activity was presented by a decreased activity of CAT in homogenates of the tongue, esophagus, stomach, and small and large intestine in comparison to the control group.Conclusion: Among those applied in the study, electromagnetic fields of a low-frequency caused the most significant disturbances of oxidative stress in the rat gastrointestinal tract.

The small and large intestine contain transcriptionally related mesenchymal stromal cell subsets that derive from embryonic Gli1+ mesothelial cells

Intestinal fibroblasts (FB) play essential roles in intestinal homeostasis. Here we show that the small and large intestinal lamina propria (LP) contain similar FB subsets that locate in specific anatomical niches and express distinct arrays of epithelial support genes. However, there were tissue specific differences in the transcriptional profile of intestinal FB subsets in the two sites. All adult intestinal LP mesenchymal stromal cells (MSC), including FB, smooth muscle cells (SMC) and pericytes derive from Gli1-expressing embryonic precursors which we identify as mesothelial cells. Trajectory analysis suggested that adult SMC and FB derive from distinct embryonic intermediates, and that adult FB subsets develop in a linear trajectory from CD81+ FB. Finally, we show that colonic subepithelial PDGFRαhi FB comprise several functionally and anatomically distinct populations that originate from an Fgfr2-expressing FB intermediate. Collectively our results provide novel insights into MSC diversity, location, function and ontogeny, with implications for our understanding of intestinal development, homeostasis and disease.

The ALPK1 pathway drives the inflammatory response to Campylobacter jejuni in human intestinal epithelial cells

The Gram-negative bacterium Campylobacter jejuni is a major cause of foodborne disease in humans. After infection, C. jejuni rapidly colonizes the mucus layer of the small and large intestine and induces a potent pro-inflammatory response characterized by the production of a large repertoire of cytokines, chemokines, and innate effector molecules, resulting in (bloody) diarrhea. The virulence mechanisms by which C. jejuni causes this intestinal response are still largely unknown. Here we show that C. jejuni releases a potent pro-inflammatory compound into its environment, which activates an NF-κB-mediated pro-inflammatory response including the induction of CXCL8, CXCL2, TNFAIP2 and PTGS2. This response was dependent on a functional ALPK1 receptor and independent of Toll-like Receptor and Nod-like Receptor signaling. Chemical characterization, inactivation of the heptose-biosynthesis pathway by the deletion of the hldE gene and in vitro engineering identified the released factor as the LOS-intermediate ADP-heptose and/or related heptose phosphates. During C. jejuni infection of intestinal cells, the ALPK1-NF-κB axis was potently activated by released heptose metabolites without the need for a type III or type IV injection machinery. Our results classify ADP-heptose and/or related heptose phosphates as a major virulence factor of C. jejuni that may play an important role during Campylobacter infection in humans.

Neglected roles of IgG Fc-binding protein secreted from airway mucin-producing cells in protecting against SARS-CoV-2 infection

Both innate immunity and acquired immunity are involved in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. The induction of Abs that neutralize the virus has been described, and certain Abs against endemic coronaviruses may cross-react with SARS-CoV-2. Detailed mechanisms to protect against the pandemic of SARS-CoV-2 remain unresolved. We previously reported that IgG Fc-binding protein (Fcγbp), a unique, large molecular weight, and mucin-like secretory Fc receptor protein, secreted from goblet cells of human small and large intestine, mediates the transportation of serum IgG onto the mucosal surface. In this review, we show that mucous bronchial gland cells and some goblet cells are immunoreactive for Fcγbp. Fcγbp traps the cross-reactive (both neutralizing and non-neutralizing) IgG bound to the virus and can consequently eliminate the virus from the mucosal surface to decrease viral loads. Fcγbp can also suppress immune overreaction by interfering with Fc-binding by macrophages and competing with complement fixation. Fcγbp secreted from mucin-producing cells of the airway functions as an important anti-infection mucosal defense. The Fcγbp-mediated mechanism can be a key factor in explaining why SARS-CoV-2 is less infective/lethal in children, and may also be involved in the unique Ab response, recurrent infection, and effects of serum therapy and vaccination.

Oral Vaccination Reduces the Effects of Lawsonia intracellularis Challenge on the Swine Small and Large Intestine Microbiome

Porcine proliferative enteropathy remains one of the most prevalent diseases in swine herds worldwide. This disease is caused by Lawsonia intracellularis, an intracellular bacterial pathogen that primarily colonizes the ileum. In this study, we evaluated changes to the microbiome of the ileal mucosa, ileal digesta, cecal digesta, and feces subsequent to challenge with L. intracellularis and to an oral live vaccine against L. intracellularis. Given that gut homogenates have been used since 1931 to study this disease, we also characterized the microbial composition of a gut homogenate from swine infected with L. intracellularis that was used as challenge material. The L. intracellularis challenge led to a dysbiosis of the microbiome of both the small and large intestine marked by an increase of pathobionts including Collinsella, Campylobacter, Chlamydia, and Fusobacterium. This microbiome response could play a role in favoring L. intracellularis colonization and disease as well as potentially predisposing to other diseases. Vaccination altered both small and large intestine microbiome community structure and led to a significant 3.03 log10 reduction in the amount of L. intracellularis shed by the challenged pigs. Vaccination also led to a significant decrease in the abundance of Collinsella, Fusobacterium, and Campylobacter among other microbial changes compared with non-vaccinated and challenged animals. These results indicate that L. intracellularis infection is associated with broad changes to microbiome composition in both the large and small intestine, many of which can be mitigated by vaccination.

Clostridium piliforme infection (Tyzzer disease) in horses: retrospective study of 25 cases and literature review

Tyzzer disease (TD) is caused by Clostridium piliforme, a gram-negative and obligate intracellular bacterium. The disease occurs in multiple species. A triad of lesions, namely colitis, hepatitis, and myocarditis, is described in cases of TD in some species, such as rats and mice. We carried out a retrospective analysis of 25 equine cases with a diagnosis of TD; 24 of 25 cases occurred in foals <45 d old; the remaining foal was 90 d old. There were 12 males and 12 females; no sex information was available for one foal. The affected breeds were Quarter Horse, Thoroughbred, Arabian, Paint, and Hanoverian. Most of the cases (19 of 25) occurred in the spring. There were 9 cases of sudden death; the remaining animals had diarrhea, fever, distended abdomen, depression, weakness, non-responsiveness, and/or recumbency. Gross findings included icterus, hepatomegaly with acinar pattern, serosal hemorrhages, pulmonary edema, and/or fluid content in small and large intestine. Microscopically, all foals had severe, multifocal, necrotizing hepatitis. Necrotizing lymphohistiocytic colitis was observed in 10 of 25 foals, and multifocal necrotizing myocarditis was found in 8 of 25. Gram-negative, Steiner-positive, intracytoplasmic filamentous bacteria were observed in hepatocytes, enterocytes, and myocardiocytes, respectively. PCR detected C. piliforme DNA in the liver (24 of 24), colon (20 of 24), and heart (5 of 25). Our results indicate that necrotic hepatitis is the hallmark of TD in horses; the so-called triad of lesions is not a consistent characteristic of the disease in this species.