Strain-specific helper T cell profile in the gut-associated lymphoid tissue

Banana Lectin: A Novel Immunomodulatory Strategy for Mitigating Inflammatory Bowel Disease

Compared to the general population, patients with inflammatory bowel disease (IBD) are less likely to be vaccinated, putting them at an increased risk of vaccine-preventable illnesses. This risk is further compounded by the immunosuppressive therapies commonly used in IBD management. Therefore, developing new treatments for IBD that maintain immune function is crucial, as successful management can lead to better vaccination outcomes and overall health for these patients. Here, we investigate the potential of recombinant banana lectin (rBanLec) as a supporting therapeutic measure to improve IBD control and possibly increase vaccination rates among IBD patients. By examining the therapeutic efficacy of rBanLec in a murine model of experimental colitis, we aim to lay the foundation for its application in improving vaccination outcomes. After inducing experimental colitis in C57BL/6 and BALB/c mice with 2,4,6-trinitrobenzene sulfonic acid, we treated animals orally with varying doses of rBanLec 0.1-10 µg/mL (0.01-1 µg/dose) during the course of the disease. We assessed the severity of colitis and rBanLec's modulation of the immune response compared to control groups. rBanLec administration resulted in an inverse dose-response reduction in colitis severity (less pronounced weight loss, less shortening of the colon) and an improved recovery profile, highlighting its therapeutic potential. Notably, rBanLec-treated mice exhibited significant modulation of the immune response, favoring anti-inflammatory pathways (primarily reduction in a local [TNFα]/[IL-10]) crucial for effective vaccination. Our findings suggest that rBanLec could mitigate the adverse effects of immunosuppressive therapy on vaccine responsiveness in IBD patients. By improving the underlying immune response, rBanLec may increase the efficacy of vaccinations, offering a dual benefit of disease management and prevention of vaccine-preventable illnesses. Further studies are required to translate these findings into clinical practice.

Allergen extraction: Factors influencing immunogenicity and sensitivity of immunoassays

Food allergy prevalence is increasing worldwide, therefore there is a high demand for reliable tests to correctly diagnose this disease. Knowledge of proteins allergenicity and how they react both in the body and in diagnostic tests is necessary to adequately assess the potential immunogenicity of both natural foods and those produced through biotechnological processes. Thus, our aim was to analyze the factors that influence the protein extraction of foods in terms of, immunogenicity and immunoassays sensitivity. Peanut proteins were extracted using four distinct extraction buffers with different pH values (physiological saline, tris buffer, borate buffer with and without β-mercaptoethanol), the protein concentration was determined by the Lowry method and polyacrylamide electrophoresis (SDS-PAGE) was used to compare the protein profile of each extract. The immunogenicity of each extract was verified by sensitizing two mouse strains (Balb/c and C57Bl/6) with a solution containing 100 μg of the extracted proteins and was determined by ELISA. Results show that extraction with the distinct buffers resulted in protein solutions with different yields and profiles. The immunogenicity of the different extracts also demonstrated distinct patterns that varied depending on the extraction methods, mouse strain and in vitro test. Immunoreactivity varied in accordance with the protein extract used to coat the microtitration plates. In conclusion, the protein profile in the extracts is critically influenced by the salt composition and pH of the extraction buffers, this in turn influences both in vivo immunogenicity and in vitro immunoreactivity.

Induction of food tolerance is dependent on intestinal inflammatory state

Food allergies are usually managed by food avoidance. Hidden allergens in food, due to cross-contamination and/or allergenic additives added during production, place an important concern in today's increasing food allergy cases worldwide. Previous studies showed that the introduction of unacquainted food components, in an inflamed intestine, results in sensitization to this food. Thus, our aim was to evaluate the kinetics of multiple food allergy induction. Adult male C57BL/6 mice were divided into five groups, four of which were submitted to an intestinal inflammation induction protocol to peanuts. Egg white (OVA) diluted 1:5 v/v in distilled water was instilled by gavage 6h-before (PRIOR), concomitant (AT) and 6h-after (DURING) the onset of the peanut challenge diet. Positive control (POS CONT) and NEG CONT received saline per gavage. Finally, animals were challenged with subcutaneous injections of OVA. Results showed no changes in diet intake were observed. Anti-OVA polyisotypic IgG antibody titers significantly increased in AT. Flow cytometry revealed significant decrease in CD4⁺CD25⁺Foxp3⁺ and significant increase in TCD8⁺ in AT. Histomorphometrically, AT and DURING were classified as Infiltrative and Partial Destruction stages. PRIOR was classified as Infiltrative, while POS CONT was classified as Partial Destruction. NEG CONT was classified as Normal. Together, our results confirm that the introduction of unfamiliar food only a few hours before the initiation of a gut inflammation process is able to induce oral tolerance, however the introduction of a dietary protein concomitant to the onset or during an ongoing gut inflammation may induce multiple allergies.

Food protein-induced enterocolitis syndrome: Dynamic relationship among gastrointestinal symptoms, immune response, and the autonomic nervous system

OBJECTIVE

To explore the relationship among gastrointestinal (GI) symptoms, immune response, and autonomic nervous system (ANS) in food protein-induced enterocolitis syndrome (FPIES) in relation to the current understanding of disease phenotype and pathogenesis.

DATA SOURCES

Relevant studies related to FPIES, GI symptomatology, and ANS were reviewed. Literature search was performed using PubMed, with keyword combinations including but not limited to FPIES, allergic GI disorders, ANS, autonomic dysfunction, dysautonomia, GI, diarrhea, vomiting, neuroimmune, and clinical phenotyping tools.

STUDY SELECTIONS

Peer-reviewed case-control studies, observational studies, reviews and guidelines, and systematic reviews related to FPIES and ANS were selected for review.

RESULTS

There is limited research directly relating GI symptoms and FPIES to the ANS and immunologic response. To support the proposed mechanisms of action related to patient symptoms, studies relevant to coexisting GI-autonomic processes and FPIES immunologic triggers were examined. These related disease processes were extrapolated to FPIES based on the current knowledge of FPIES phenotype and pathogenesis.

CONCLUSION

The etiology of FPIES and the underlying mechanisms triggering symptoms are not well understood. On the basis of the exaggerated GI symptoms and hemodynamic response observed, the ANS likely plays an important role in FPIES, possibly as a compensatory response. The trigger for this cascade of symptoms may be related to the disruption of immunologic homeostasis that typically contributes to immune tolerance. To more accurately evaluate FPIES pathophysiology necessitates understanding the diverse spectrum of presenting symptoms. A consistent and comprehensive symptom assessment tool may improve our understanding of this dynamic relationship.

Strain specific response of mice to IMQ-induced psoriasis

OBJECTIVES

Psoriasis is an autoimmune, inflammatory disease that needs a reliable animal model. Imiquimod (IMQ)-induced psoriasis is a widely used preclinical tool for psoriasis research. However, this model is sensitive to the genetic variation of mice. The present study explores mice's genetic background on disease stability and severity induced by IMQ.

METHODS

Three distinct strains of mice (Balb/c, C57BL/6, and Swiss albino) were divided into four groups (Vaseline, IMQ, IMQ+Clobetasol, and IMQ+Curcumin). Psoriasis area severity index (PASI) score, ear/back skin thickness, body weight alterations, and histopathological examination were employed to analyze disease severity. The spleen index studied the systemic effect. Strain effect on oxidative stress induced by IMQ was evaluated by estimating antioxidant factors, superoxide dismutase (SOD), catalase, and glutathione (GSH).

RESULTS

IMQ application resulted in increased PASI score, thickness, and alterations in body weight, confirming disease development in all the mice. However, the disease stability/severity between these strains was not identical. Although IMQ application caused splenomegaly, IMQ+curcumin treated C57BL/6 mice demonstrated a synergistic effect of IMQ and curcumin on the spleen resulting in increased splenomegaly. Decreased cellular enzyme activity in SOD, Catalase, and levels of GSH was observed in IMQ challenged mice, indicating the participation of the redox system in the genesis of the disease that was comparable among the strains.

CONCLUSIONS

These results indicate the existence of strain-dependent development of the disease. The Swiss model was found to be better in terms of disease severity and stability than other models. Further, a detailed mechanistic study might help to explain the pathological difference between these strains.

Role of Type I Interferon (IFN) in the Respiratory Syncytial Virus (RSV) Immune Response and Disease Severity

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract disease in children <2 years of age. Increased morbidity and mortality have been reported in high-risk patients, such as premature infants, patients with cardiac disease, and severely immune compromised patients. Severe disease is associated with the virulence of the virus as well as host factors specifically including the innate immune response. The role of type I interferons (IFNs) in the response to RSV infection is important in regulating the rate of virus clearance and in directing the character of the immune response, which is normally associated with protection and less severe disease. Two RSV non-structural proteins, NS1 and NS2, as well as the envelope G glycoprotein are known to suppress type I IFN production and a robust type I IFN response to RSV does not occur in human infants or neonatal mouse models of RSV infection. Additionally, presence of type I IFNs are associated with mild symptoms in infants and administration of IFN-α prior to infection of neonatal mice with RSV reduces immunopathology. This evidence has driven RSV prophylaxis and therapeutic efforts to consider strategies for enhancing type I IFN production.

Oral neonatal antibiotic treatment perturbs gut microbiota and aggravates central nervous system autoimmunity in Dark Agouti rats

Gut microbiota dysbiosis has been considered the essential element in the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Antibiotics were administered orally to Dark Agouti (DA) rats early in their life with the aim of perturbing gut microbiota and investigating the effects of such intervention on the course of EAE. As a result, the diversity of the gut microbiota was reduced under the influence of antibiotics. Mainly, Firmicutes and Actinobacteria were replaced by Proteobacteria and Bacteroidetes, while decreased proportions of Clostridia and Bacilli classes were accompanied by an increase in Gamma-Proteobacteria in antibiotic-treated animals. Interestingly, a notable decrease in the Helicobacteraceae, Spirochaetaceae and Turicibacteriaceae was scored in antibiotic-treated groups. Also, levels of short chain fatty acids were reduced in the faeces of antibiotic-treated rats. Consequently, aggravation of EAE, paralleled with stronger immune response in lymph nodes draining the site of immunization, and increased inflammation within the CNS, were observed in antibiotic-treated DA rats. Thus, the alteration of gut microbiota leads to an escalation of CNS-directed autoimmunity in DA rats. The results of this study indicate that antibiotic use in early life may have subsequent unfavourable effects on the regulation of the immune system.

Functional and Histological Gender Comparison of Age-Matched Rats after Moderate Thoracic Contusive Spinal Cord Injury

Spinal cord injury (SCI) afflicts hundreds of thousands of Americans, and most SCI (∼80%) occurs in males. In experimental animal models, however, many studies used females. Funding agencies like the National Institutes of Health recommend that new proposed studies should include both genders due to variations in gender response to injuries, diseases, and treatments. However, cost and considerations for some animal models, such as SCI, affect investigators in adapting to this recommendation. Research has increased comparing gender effects in various disease and injury models, including SCI. However, most studies use weight-matched animals, which poses issues in comparing results and outcomes. The present study compared histologic and functional outcomes between age-matched male and female Sprague-Dawley rats in a moderate thoracic contusion SCI model. Cresyl violet and eosin staining showed no significant differences in lesion volume between genders after 9 weeks post-SCI (p > 0.05). Luxol fast blue-stained spared myelin was similar between genders, although slightly greater (∼6%) in spared myelin, compared with cord volume (p = 0.044). Glial reactivity and macrophage labeling in the lesion area was comparable between genders, as well. Basso, Beattie, Bresnahan (BBB) functional scores were not significantly different between genders, and Hargreaves thermal hyperalgesia and Gridwalk sensorimotor analyses also were similar between genders, compared with uninjured gender controls. Analysis of covariance showed weight did not influence functional recovery as assessed through BBB (p = 0.65) or Gridwalk assessment (p = 0.63) in this study. In conclusion, our findings suggest age-matched male and female rats recover similarly in a common clinically relevant SCI model.

A histomorphometric classification system for normal and inflamed mouse duodenum-Quali-quantitative approach

Gut-associated intestinal lymphoid tissue, the largest secondary lymphoid organ in the human body, constantly samples antigens from the gut lumen, presenting as a default response the activation of TCD4⁺ FOXP3⁺ regulatory T cells that secrete a profile of anti-inflammatory cytokines maintaining gut homeostasis denominated from an immunological perspective as mucosal tolerance. However, when antigens are sampled in an inflammatory setting, the immune response may either be protective, in the case of harmful pathogens, or cause further inflammatory reactions as in food allergy, inflammatory bowel diseases, coeliac disease or food protein-induced enterocolitis syndrome. Therefore, there is a need for accurate and consistent experimental models. However, a drawback in comparing these models is the lack of a classification system similar to that which is already used for humans. Thus, the aim of this work was to propose a classification system of the small intestinal histomorphology in experimental mice. To do this we used a mouse antigen-specific gut inflammation model developed by our research group. Duodenum sections stained with haematoxylin-eosin and Alcian blue were scanned using the APERIO scanning system and analysed with the ImageScope^® software. The evaluated parameters were villus area, villus height and width, enterocyte count, mononuclear intra-epithelial leucocyte and goblet cell counts, and architectural and cellular ratios. Food-sensitized animals challenged with a diet containing the corresponding food allergen presented, as for humans, time-dependent shortened and widened villi accompanied by leucocyte infiltrate and loss of goblet cells. With these data, we were able to establish a classification system for experimental intestinal inflammation in mice thus permitting better comparisons among and between experiments than has been possible previously.

Gut microbiome and bone

The gut microbiome is now viewed as a tissue that interacts bidirectionally with the gastrointestinal, immune, endocrine and nervous systems, affecting the cellular responses in numerous organs. Evidence is accumulating of gut microbiome involvement in a growing number of pathophysiological processes, many of which are linked to inflammatory responses. More specifically, data acquired over the last decade point to effects of the gut microbiome on bone mass regulation and on the development of bone diseases (such as osteoporosis) and of inflammatory joint diseases characterized by bone loss. Mice lacking a gut microbiome have bone mass alteration that can be reversed by gut recolonization. Changes in the gut microbiome composition have been reported in mice with estrogen-deficiency osteoporosis and have also been found in a few studies in humans. Probiotic therapy decreases bone loss in estrogen-deficient animals. The effect of the gut microbiome on bone tissue involves complex mechanisms including modulation of CD4⁺T cell activation, control of osteoclastogenic cytokine production and modifications in hormone levels. This complexity may contribute to explain the discrepancies observed betwwen some studies whose results vary depending on the age, gender, genetic background and treatment duration. Further elucidation of the mechanisms involved is needed. However, the available data hold promise that gut microbiome manipulation may prove of interest in the management of bone diseases.

Protective effects of carbonyl iron against multiple low-dose streptozotocin-induced diabetes in rodents

Particulate adjuvants have shown increasing promise as effective, safe, and durable agents for the stimulation of immunity, or alternatively, the suppression of autoimmunity. Here we examined the potential of the adjuvant carbonyl iron (CI) for the modulation of organ-specific autoimmune disease-type 1 diabetes (T1D). T1D was induced by multiple low doses of streptozotocin (MLDS) that initiates beta cell death and triggers immune cell infiltration into the pancreatic islets. The results of this study indicate that the single in vivo application of CI to MLDS-treated DA rats, CBA/H mice, or C57BL/6 mice successfully counteracted the development of insulitis and hyperglycemia. The protective action was obtained either when CI was applied 7 days before, simultaneously with the first dose of streptozotocin, or 1 day after MLDS treatment. Ex vivo cell analysis of C57BL/6 mice showed that CI treatment reduced the proportion of proinflammatory F4/80⁺ CD40⁺ M1 macrophages and activated T lymphocytes in the spleen. Moreover, the treatment down-regulated the number of inflammatory CD4⁺ IFN-γ⁺ cells in pancreatic lymph nodes, Peyer's patches, and pancreas-infiltrating mononuclear cells, while simultaneously potentiating proportion of CD4⁺ IL17⁺ cells. The regulatory arm of the immune system represented by CD3⁺ NK1.1⁺ (NKT) and CD4⁺ CD25⁺ FoxP3⁺ regulatory T cells was potentiated after CI treatment. In vitro analysis showed that CI down-regulated CD40 and CD80 expression on dendritic cells thus probably interfering with their antigen-presenting ability. In conclusion, particulate adjuvant CI seems to suppress the activation of the innate immune response, which further affects the adaptive immune response directed toward pancreatic beta cells.