Role of mesenchymal stem cells and short chain fatty acids in allergy: A prophylactic therapy for future.

Allergic diseases are broadly classified as IgE-mediated type-I hypersensitivity immune reactions due to exposure to typically harmless substances known as allergens. These allergenic substances activate antigen presenting cells, which further triggers T-helper 2 cells immune response and class switch B-cells for synthesis of allergen-specific IgE, followed by classical activation of inflammatory mast cells and eosinophils, which releases preformed mediators involved in the cascade of allergic symptoms. However, the role of Mesenchymal stem cells (MSCs) in tissue repair ability and immunomodulation, makes them as an appropriate tool for treatment of various allergic diseases. Several clinical and preclinical studies show that MSCs could be a promising alternative therapy to allergic diseases. Further, short chain fatty acids, produced from gut microbes by breaking down complex fibre-rich foods, acts through G-coupled receptor mediated activation of MSCs, and their role as key players involved in amelioration of allergic inflammation needs further investigation. Therefore, there is a need for understating the role of SCFAs on the activation of MSCs, which might shed light on the development of new therapeutic regime in allergy treatment. In summary, this review focuses on the underlying of therapeutic role of MSCs in different allergic diseases and the prospects of SCFA and MSC therapy.

Antiviral and immunomodulatory activity of curcumin: A case for prophylactic therapy for COVID-19.

Coronavirus disease-19 (COVID-19), a devastating respiratory illness caused by SARS-associated coronavirus-2 (SARS-CoV-2), has already affected over 64 million people and caused 1.48 million deaths, just 12 months from the first diagnosis. COVID-19 patients develop serious complications, including severe pneumonia, acute respiratory distress syndrome (ARDS), and or multiorgan failure due to exaggerated host immune response following infection. Currently, drugs that were effective against SARS-CoV are being repurposed for SARS-CoV-2. During this public health emergency, food nutraceuticals could be promising prophylactic therapeutics for COVID-19. Curcumin, a bioactive compound in turmeric, exerts diverse pharmacological activities and is widely used in foods and traditional medicines. This review presents several lines of evidence, which suggest curcumin as a promising prophylactic, therapeutic candidate for COVID-19. First, curcumin exerts antiviral activity against many types of enveloped viruses, including SARS-CoV-2, by multiple mechanisms: direct interaction with viral membrane proteins; disruption of the viral envelope; inhibition of viral proteases; induce host antiviral responses. Second, curcumin protects from lethal pneumonia and ARDS via targeting NF-κB, inflammasome, IL-6 trans signal, and HMGB1 pathways. Third, curcumin is safe and well-tolerated in both healthy and diseased human subjects. In conclusion, accumulated evidence indicates that curcumin may be a potential prophylactic therapeutic for COVID-19 in the clinic and public health settings.

Bortezomib treatment diminishes hazelnut-induced intestinal anaphylaxis in mice.

Food allergy is a common health problem and can cause anaphylaxis. Avoidance of the offending food allergen is still the mainstay therapeutic approach. In this study, we investigated the role of plasma cell reduction by proteasome inhibition in a murine model of food allergy and examined the impact of this treatment on the systemic and local immune response. For this purpose, intestinal anaphylaxis was induced in BALB/c mice with the food allergen hazelnut, in conjunction with different adjuvants (alum and Staphylococcal enterotoxin B SEB) and different administration routes (oral and intraperitoneal). In both models, allergy symptoms were observed, but the clinical severity was more pronounced in the hazelnut-alum model than in the hazelnut-SEB model. Accordingly, allergen-specific immunoglobulin E (IgE) against hazelnut was detectable, and mast cell protease-1 in serum was increased after allergen provocation. Treatment with the proteasome inhibitor bortezomib reduced plasma cells and resulted in an abolishment of hazelnut allergen-specific IgE, which was associated with amelioration of clinical symptoms as well as a significant decrease in both CD19(+) and follicular B lymphocytes. Our data demonstrate the importance of allergen-specific IgE in food allergy and point to B cells as potential therapeutic targets for its treatment.

Opposing effects on immune function and skin barrier regulation by the proteasome inhibitor bortezomib in an allergen-induced eczema model.

Proteasome inhibition (PI) has been reported to interfere with antibody-driven autoimmune diseases. The impact of PI on the allergic immune response and on skin diseases like atopic dermatitis (AD) has not been thoroughly explored, however. Here, we examined whether the PI bortezomib interferes with the allergic immune response and the severity of AD by using an established mouse model of allergen-driven dermatitis, to which bortezomib was applied after the establishment of systemic sensitization to ovalbumin. The treatment indeed resulted in a remarkable decrease in total and allergen-specific plasma cells/antibody-secreting cells, as evidenced by flow cytometry and ELISpot, respectively. This was accompanied by rapid reductions in serum antibody titres, including a prominent reduction of the IgE isotype. CD4+ and CD8+ cells were greatly diminished in lesional skin on immunohistological staining. The impressive effects at the level of immune modulation did not result in any improvement in the eczema, however. Following up on this unexpected result, we found that the skin itself was susceptible to bortezomib, by which it was instructed to lower the expression of critical skin barrier genes, especially transglutaminase-1 and filaggrin. Together, bortezomib eliminates plasma cells and decreases immunoglobulin responses, including allergenic IgE. Although anti-inflammatory effects are detectable in the skin, counter-regulatory effects from PI on resident skin cells likely undermine improvement in the eczema. These results caution against the therapeutic use of bortezomib for inflammatory skin disorders, which are characterized by inherently impaired barrier function, especially AD.