Delayed-type Hypersensitivity Response Research Articles

Immunomodulatory Effects of Citrus Species Ethanol Extracts on Cellular Immune Responses in Wistar Rats and Mice

Currenty, Citrus reticulata has been found to modulate RAW 264.7 macrophage cell line. In the present study, the immunomodulatory effects of Citrus species peel extracts, including Citrus microcarpa, C. limon L., C. sinensis L. and C. hystrix were investigated on cellular immune responses in Wistar rats and mice. Mice were treated with ethanol extracts of Citrus species orally at dosages of 25, 50 and 100 mg/kg bw for 7 days. The phagocytosis activity of the extracts was examined using the carbon clearance method. Meanwhile, oral administration of Citrus species ethanol extracts at dosages of 17.5, 35 and 70 mg/kg bw was administered to Wistar rats to assess the effect of extracts on the delayed-type hypersensitivity (DTH) response using paw edema-method. Thin Layer Chromatography (TLC)-densitometry analysis was also performed. In both animal models, all extracts enhanced the cellular immune responses. Amongst the samples, C. sinensis, at the dose of 100 mg/kg bw in mice and 70 mg/kb bw in rats, demonstrated the highest stimulation on phagocytosis activity and DTH response, respectively. Except C. microcarpa, rutin was found in all Citrus species. The results indicate that Citrus species, particularly C. sinensis, have the potential to be developed into a potent immunostimulatory agent. HIGHLIGHTS The immunomodulatory effects Citrus species were investigated using mice and rats as animal models. Citrus microcarpa, C. limon, C. sinensis L. and C. hystrix were able to stimulate phagocytosis in mice and delayed-type hypersensitivity response in rats. Citrus sinensis demonstrated the highest stimulation on phagocytosis activity and delayed-type hypersensitivity response. Rutin was found in all Citrus species, except in microcarpa peels extract. GRAPHICAL ABSTRACT

Intranasal Trans-Sialidase Vaccine Mitigates Acute and Chronic Pathology in a Preclinical Oral Chagas Disease Model

Chagas disease, caused by Trypanosoma cruzi, leads to severe complications in 30% of infected individuals, including acute myocarditis and chronic fibrosing cardiomyopathy. Despite the significant burden of this disease, there is currently no licensed vaccine available to prevent it. This study aimed to evaluate the mucosal and systemic immunogenicity as well as the prophylactic efficacy of a mucosal vaccine candidate and its impact on both acute and chronic cardiomyopathy. The results showed that the nasal administration of trans-sialidase (TS) plus c-di-AMP (TS+A) vaccine elicited a NALT expression of IFN-γ, IL-17a and IL-4 mRNA as well as a nasal-specific production of IgA. An in vivo challenge with TS also triggered increased proliferation of lymphocytes from the NALT, sentinel cervical lymph node, and spleen. TS+A immunization increased the plasma levels of Th1/Th2/Th17 cytokines and elicited an evident cellular response by which to judge enhanced delayed-type hypersensitivity responses following a TS footpad challenge. After oral infection, TS+A-vaccinated mice showed significantly reduced parasitemia and parasite load in the heart, muscles and intestines, while markers of hepatic and muscle damage as well as clinical manifestations of acute infection were strongly diminished. TS+A also attenuated acute myocarditis and the expression of inflammatory markers in the heart. The protection conferred by TS+A extended into the chronic phase, where it resulted in a clear reduction in chronic myocarditis, fibrosis and functional electrocardiographic abnormalities, associated with a decreased expression of the pro-fibrotic TGF-β. These results revealed that it is possible to develop a mucosal vaccine against T. cruzi based on TS and c-di-AMP that is capable of reducing the development of Chagas cardiomyopathy, the hallmark of Chagas disease.

Antioxidant and immunomodulatory activities of ethanol extracts from Syzygium cumini L. Skeels and Pogostemon cablin Benth

Syzygium cumini and Pogostemon cablin are mostly cultivated in tropical climates for culinary and perfumery purposes, yet their potential medicinal properties remain underreported. The aim of this study was to examine the antioxidant and immunomodulatory activities of ethanol extracts from S. cumini (EESC) and P. cablin (EEPC). Reflux extraction was carried out using 96% ethanol on the collected plant specimens to produce EESC and EEPC. Secondary metabolites of each extract were identified using gas chromatography-mass spectrometry (GC-MS). The extracts were measured for total phenol and flavonoid levels and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. The immunomodulatory activity test was carried out in vivo by assessing several parameters, including the phagocytic index via the carbon clearance method, organ indices, antibody titers, and delayed-type hypersensitivity (DTH) response, using sheep red blood cells (SRBC) as antigens. The extracts were also examined for their anti-inflammatory activity in acute and chronic inflammation models. In the DPPH antioxidant test, EESC and EEPC had IC50 values of 12.33 µg/mL and 182.17 µg/mL, respectively. Both extracts showed immunosuppressant activity, marked by a phagocytic index of <1. EESC yielded lower organ indices for the liver (p=0.025 at 200 mg/kg BW), spleen (p=0.028 at 100 mg/kg BW), and thymus (p=0.032 at 200 mg/kg BW) compared to the control group. For EEPC, lower organ indices were observed in the liver at 100 mg/kg BW (p=0.005) and 200 mg/kg BW (p=0.031). In the primary antibody titer and DTH tests, both EESC and EEPC showed immunosuppressant activity at 200 and 400 mg/kg BW (p<0.05). The extracts suppressed both the innate and adaptive immune systems. Both EEPC (p=0.004) and EESC at 100 mg/kg BW (p=0.03) significantly reduced serum TNF-α levels. In conclusion, EESC and EEPC have the potential as immunosuppressive and anti-inflammatory agents.

Antigenic reactivity of Leishmania (Viannia) lainsoni axenic amastigote proved to be a suitable alternative for optimizing Montenegro skin test

BackgroundLaboratory diagnosis of American cutaneous leishmaniasis (ACL) requires a tool amenable to the epidemiological status of ACL in Brazil. Montenegro skin test (MST), an efficient immunological tool used for laboratory diagnosis of ACL, induces delayed-type hypersensitivity (DTH) response to the promastigote antigens of Leishmania; however, human immune responses against infection are modulated by the amastigote of the parasite. Leishmania (V.) lainsoni induces strong cellular immunity in humans; therefore, the antigenic reactivity of its axenic amastigote (AMA antigen) to MST was evaluated for the laboratory diagnosis of ACL.MethodsAmong 70 individuals examined, 60 had a laboratory-confirmed diagnosis of ACL; 53 had localized cutaneous leishmaniasis (LCL), and 7 had mucosal leishmaniasis (ML). Patients were treated at the Evandro Chagas Institute’s leishmaniasis clinic, Pará State, Brazil. Ten healthy individuals with no history of ACL (control group) were also examined. Leishmania (V.) braziliensis promastigote antigen (PRO) was used to compare the reactivity with that of AMA antigen. Paired Student’s t-test, kappa agreement, and Spearman test were used to evaluate the reactivity of AMA and PRO.ResultsThe mean reactivity of AMA in ACL patients was 19.4 mm ± 13.3, which was higher (P < 0.001) than that of PRO: 12.1 mm ± 8.1. MST reactivity according to the clinical forms revealed that AMA reactivity in LCL and ML, 18.8 mm ± 13.3 and 24.3 mm ± 13.7, was higher (P < 0.001) than that of PRO, 11.8 mm ± 8.2 and 14.6 mm ± 8.4, respectively.ConclusionAMA reactivity was higher than that of PRO, indicating that AMA is a promising alternative for optimizing MST in the laboratory diagnosis of ACL.Graphical abstract

Cellular immunity to nucleoproteins (NP) of Crimean-Congo hemorrhagic fever virus (CCHFV) and Hazara Virus (HAZV).

Crimean-Congo Hemorrhagic Fever Virus (CCHFV) is a globally significant vector-borne pathogen with no internationally-licensed preventative and therapeutic interventions. Hazara virus (HAZV), on the other hand, a related Orthonairovirus, has not been reported as a human pathogen. HAZV has been proposed as a surrogate model for studying CCHFV, bisosafety level 4 (BSL-4) agent. Previously, we investigated the humoral immune responses between NPs of these viruses and in this study, we extended the scrutiny to cellular immune responses elicited by NPs of CCHFV and HAZV. Here, mice were immunized with recombinant CCHFV NP and HAZV NP to evaluate the correlates of cell-mediated immunity (CMI). Delayed-type hypersensitivity (DTH) responses were assessed by challenging immunized mice with CCHFV-rNP or HAZV-rNP on the footpad and lymphocyte proliferation assays (LPAs) were performed by stimulating splenocytes in vitro with CCHFV-rNP or HAZV-rNP to compare cellular immune responses. In all test groups, strong DTH and LPA responses were detected against homologous and heterologous challenging antigens. To assess the cytokine response, an RT-qPCR -specific for cytokine mRNAs was utilized. Interestingly, CCHFV NP stimulated groups exhibited a significantly elevated mRNA level of interleukin 17A (IL-17) compared to HAZV NP, indicating a notable difference in immune responses. This study presents comparison between CMI elicited by NPs of CCHFV and HAZV and contributes to the understanding of a highly pathogenic virus, particularly in the context of the declaration of CCHFV by World Health Organization's (WHO) as a major viral threat to the world.

501 The effect of dietary camelina, flaxseed, and canola oil supplementation on skin fatty acid profile, inflammation and immune responses in healthy adult horses

Abstract As n-6 and n-3 fatty acids (FA) have pro- and anti-inflammatory effects, respectively, supplemental oils have the potential to impact inflammation, the immune response, and skin and coat health. This study aimed to evaluate the effects of camelina (CAM), in comparison to canola (OLA) and flaxseed (FLX) oil on the skin FA profile, inflammation, and the immune response in horses. Horses [n = 24; 14.2 ± 4.8 yr; 518 ± 63 kg body weight (BW)] were acclimated to sunflower oil over 4 wk. Groups were balanced by location, age, weight, sex, and breed and randomly assigned one of the three treatments (CAM, OLA, FLX). Horses were fed their assigned oil at a dose of 0.37 g/kg BW for 16 wk. Skin samples were collected on wk 16, and the skin FA composition was analyzed by gas chromatography. On wk 10 and 12, keyhole limpet hemocyanin (KLH) was administered intramuscularly to each horse to stimulate a systemic immune response. Blood was collected on wk 14 and 16 for the evaluation of plasma KLH immunoglobulin G (IgG) concentrations using a modified ELISA protocol and results were presented as optical density units. On wk 12, after the first KLH injection, a delayed-type hypersensitivity (DTH) test was performed by intradermally injecting KLH and the area of swelling was measured using the software ImageJ at 0.5-, 1-, 8-, 24-, 48-, 72-, and 96-h post-injection. Data were analyzed using the GLIMMIX procedure of SAS considering the effects of treatment, time, and their interaction as fixed, and the effects of horse and location as random. Repeated measures on horses were modelled using a spatial power covariance structure. Significance was declared at P ≤ 0.05 and when fixed effects were significant, means were separated using Tukey-Kramer adjustments. Immune and inflammatory responses were produced by the KLH injections; however, there were no differences among treatment groups regarding KLH antibody and DTH response (P &amp;gt; 0.44). The percentages of palmitic (P = 0.02) and stearic acid (P = 0.03) in the skin at wk 16 were greater in FLX as compared with CAM but neither differed from the OLA. The percentage of linoleic acid (P = 0.01) was greater in CAM than OLA but neither differed from FLX at wk 16. The percentage of all other FA was similar among treatment groups (P &amp;gt; 0.06). These results suggest that CAM is comparable to FLX and OLA regarding support of an immune and inflammatory response, and the oil FA composition was not reflected in the skin FA profile after feeding for 16 wk as hypothesized. In conclusion, at the dose provided, CAM supports a similar immune and inflammatory response to KLH as FLX and OLA; however, the lack of incorporation of FA from the diet into the skin should be further explored.

Immunomodulation Induced in BALB/c Mice after Subacute Exposure to Hydroalcoholic Extract of Artimisia Dracunculus.

Tarragon, with the scientific name of Artemisia dracunculus, is a perennial herbaceous plant with a wide spectrum of pharmacologic properties. In the current investigation, BALB/c mice were used to examine the immunomodulatory effects of hydroalcoholic extract of tarragon (HET). Mice were treated with hydroalcoholic extract of Artimisia dracunculus (HET) at two doses (250 and 500 mg/kg) for 14 days. The host hematological parameters, spleen cellularity histopathology, hemagglutination titer assay (HA), delayed-type hypersensitivity (DTH) responses, IFN-γ and IL-4 levels produced by spelenocytes, and the proliferation of lymphocytes were assayed. HET at a high dose significantly could increase the number of white blood cells and lymphocytes compared to the control group. The lymphocyte proliferation in exposure to PHA significantly increased in the HET group at both doses compared to the control group, whilst this index in the presence of LPS increased significantly for the 500 mg/kg-HET group only. Moreover, in the HA and DTH tests, HET significantly increased the proliferation of lymphocytes as compared with the control group. Furthermore, HET significantly increased the amount of IFN-γ parallel to a decrease in the level of IL-4 in compared to the control group. Based on our findings, HET has potent immunostimulant characteristics. More investigation into tarragon's potential to be used in the treatment of disorders caused by a weakened immune response should be conducted.

Human Milk Oligosaccharides in Combination with Galacto- and Long-Chain Fructo-Oligosaccharides Enhance Vaccination Efficacy in a Murine Influenza Vaccination Model.

Early-life nutrition significantly impacts vaccination efficacy in infants, whose immune response to vaccines is weaker compared to adults. This study investigated vaccination efficacy in female C57Bl/6JOlaHsd mice (6 weeks old) fed diets with 0.7% galacto-oligosaccharides (GOS)/long-chain fructo-oligosaccharides (lcFOS) (9:1), 0.3% human milk oligosaccharides (HMOS), or a combination (GFH) for 14 days prior to and during vaccination. Delayed-type hypersensitivity (DTH) was measured by assessing ear swelling following an intradermal challenge. Influvac-specific IgG1 and IgG2a levels were assessed using ELISAs, while splenic T and B lymphocytes were analyzed for frequency and activation via flow cytometry. Additionally, cytokine production was evaluated using murine splenocytes co-cultured with influenza-loaded dendritic cells. Mice on the GFH diet showed a significantly enhanced DTH response (p < 0.05), increased serological IgG1 levels, and a significant rise in memory B lymphocytes (CD27+ B220+ CD19+). GFH-fed mice also exhibited more activated splenic Th1 cells (CD69+ CXCR3+ CD4+) and higher IFN-γ production after ex vivo restimulation (p < 0.05). These findings suggest that GOS/lcFOS and HMOS, particularly in combination, enhance vaccine responses by improving memory B cells, IgG production, and Th1 cell activation, supporting the potential use of these prebiotics in infant formula for better early-life immune development.

Pigment Dispersion Contributes to Ocular Immune Privilege in a DBA/2J Mouse Model of Pigmentary Glaucoma.

To investigate the effects of anterior chamber pigment dispersion on ocular immune privilege and the possible mechanisms involved in a DBA/2J mouse model of pigmentary glaucoma. DBA/2J mice were utilized as a pigment dispersion model, and age-matched C57BL/6J mice were used as the control group in this study. Proteins in the aqueous humor (AH) and serum were quantified using the bicinchoninic acid assay. Immune cells in the AH were detected using hematoxylin and eosin staining and immunocytochemistry. The expression of TGF-β2 in the AH and cytokine levels (IL-10, IFN-γ) in serum were measured using ELISA. Anterior chamber-associated immune deviation (ACAID) was induced in DBA/2J mice by injecting antigens into the anterior chamber. Delayed-type hypersensitivity (DTH) assays were used to assess the induction of ACAID. In DBA/2J mice, before and after pigment dispersion, following anterior chamber injection of pigment particles, and after ACAID modeling, the expression of regulatory T cells (Tregs) was detected using flow cytometry. Compared to C57BL/6J mice, the protein concentration, immune cell count, and TGF-β2 levels in the AH were elevated in DBA/2J mice. Protein concentration and IL-10 levels in serum were increased, while IFN-γ levels were decreased in DBA/2J. Additionally, the expression of Treg cells in the spleen of DBA/2J mice was significantly increased after pigment dispersion and anterior chamber injection of pigment particles. At 3 and 6 months, DTH responses in DBA/2J mice were not inhibited, thus preventing ACAID induction. However, the opposite was observed at 9 months in DBA/2J mice. Furthermore, the ACAID group exhibited an augmented expression of Treg cells. Dispersion of pigment particles in the anterior chamber of the eye enhances the state of ocular immune privilege by influencing the immunosuppressive microenvironment and inducing more Treg cells to reestablish ACAID.

Изучение некоторых функциональных характеристик ферментативных гидролизатов пищевых белков

Food allergy is a matter of global concern, proteins being a popular allergen worldwide. Enzymatic protein hydrolysates serve as hypoallergenic components in functional foods. This article describes enzymatic hydrolysates of egg and soy proteins as potential antigens, sensitizers, and antioxidants. The research featured soy protein isolate and egg albumin. The protein hydrolysates were obtained in a two-step process with pepsin and trypsin to measure hydrolysis, total antioxidant activity, and residual antigenicity. The sensitizing ability of native proteins and their hydrolysates was studied using a delayed-type hypersensitivity (DTH) skin test of paw swelling in mice. The egg albumin and soy protein were hydrolyzed by sequentially adding the proteases, i.e., pepsin and trypsin. The degree of protein hydrolysis was calculated against total nitrogen and its contents in non-hydrolyzed raw materials and hydrolysate. It was 82.6% for the egg hydrolysate and 88.3% for the soy hydrolysate, the total antioxidant activity being 114.3 and 91.4 mg/100 mL, respectively. The residual antigenicity of the hydrolysates determined by ELISA in a sandwich version was 1.55×10–4 and 3.30×10–4 RU, respectively. The native egg and soy proteins demonstrated good allergenic properties, and the DTH response index increased fivefold. The hydrolysates reduced the DTH response indices by an average of 3.5 for egg hydrolysate and 2.6 times for soy hydrolysate. The resulting enzymatic hydrolysates of egg albumin and soy protein demonstrated a high degree of hydrolysis and antioxidant activity. They had low residual antigenicity (10–4) and low sensitizing ability. The resulting enzymatic hydrolysates could be used as hypoallergenic components and antioxidants in new functional foods.

The effect of modified Qiyuan paste on mice with low immunity and sleep deprivation by regulating GABA nerve and immune system

BackgroundLow immunity and sleep disorders are prevalent suboptimal health conditions in contemporary populations, which render them susceptible to the infiltration of pathogenic factors. LJC, which has a long history in traditional Chinese medicine for nourishing the Yin and blood and calming the mind, is obtained by modifying Qiyuan paste. Dendrobium officinale Kimura et Migo has been shown to improve the immune function in sleep-deprived mice. In this study, based on the traditional Chinese medicine theory, LJC was prepared by adding D. officinale Kimura et Migo to Qiyuan paste decoction.MethodsIndicators of Yin deficiency syndrome, such as back temperature and grip strength, were measured in each group of mice; furthermore, behavioral tests and pentobarbital sodium-induced sleep tests were performed. An automatic biochemical analyzer, enzyme-linked immunosorbent assay kit, and other methods were used to determine routine blood parameters, serum immunoglobulin (IgG, IgA, and IgM), cont (C3, C4), acid phosphatase (ACP) and lactate dehydrogenase (LDH) levels in the spleen, serum hemolysin, and delayed-type hypersensitivity (DTH) levels. In addition, serum levels of γ-aminobutyric acid (GABA) and glutamate (Glu) were detected using high-performance liquid chromatography (HPLC). Hematoxylin–eosin staining and Nissl staining were used to assess the histological alterations in the hypothalamus tissue. Western blot and immunohistochemistry were used to detect the expressions of the GABA pathway proteins GABRA1, GAD, GAT1, and GABAT1 and those of CD4+ and CD8+ proteins in the thymus and spleen tissues.ResultsThe findings indicated that LJC prolonged the sleep duration, improved the pathological changes in the hippocampus, effectively upregulated the GABA content in the serum of mice, downregulated the Glu content and Glu/GABA ratio, enhanced the expressions of GABRA1, GAT1, and GAD, and decreased the expression of GABAT1 to assuage sleep disorders. Importantly, LJC alleviated the damage to the thymus and spleen tissues in the model mice and enhanced the activities of ACP and LDH in the spleen of the immunocompromised mice. Moreover, serum hemolysin levels and serum IgG, IgA, and IgM levels increased after LJC administration, which manifested as increased CD4+ content, decreased CD8+ content, and enhanced DTH response. In addition, LJC significantly increased the levels of complement C3 and C4, increased the number of white blood cells and lymphocytes, and decreased the percentage of neutrophils in the blood.ConclusionsLJC can lead to improvements in immunocompromised mice models with insufficient sleep. The underlying mechanism may involve regulation of the GABA/Glu content and the expression levels of GABA metabolism pathway-related proteins in the brain of mice, enhancing their specific and nonspecific immune functions.Graphical

Anti-inflammatory Property of Ethanolic Extract of Cleome spinosa Leaves in an in vivo Model of Delayed-type Hypersensitivity

Objectives Delayed-type hypersensitivity (DTH) reactions represent a clinically important class of immune responses that have wide-ranging implications in various health and disease conditions. The existing anti-inflammatory drugs to treat DTH have several shortcomings including severe side-effects. Thus, a new plant-derived anti-inflammatory drug with no or less toxicity would be effective in treating DTH. The Cleome genus has been routinely used to cure various ailments including inflammation. This study investigates the anti-inflammatory properties of the ethanolic leaf extract of Cleome spinosa (CSE) in a DTH model for the first time. Materials and Methods DTH response was induced by 2, 4-di nitro-fluorobenzene in the mouse foot pad. Histological sectioning of the paw was carried out to find changes in the architecture of the tissue. Serum tumour necrosis factor-alpha (TNF-α) was estimated through enzyme linked immunosorbent assay (ELISA), and the bioactive compounds present in CSE were analysed through reversed phase-high-performance liquid chromatography. Results With CSE treatment, the oedema in the resensitized paw alleviated faster with no loss of digits compared to the controls. Histological study of the resensitized paw showed less dermal and sub-dermal thickening and less collagen deposition that regained normal tissue architecture during the healing process with CSE treatment. CSE treatment did not show any adverse haematological and histopathological changes in the visceral organs of mice. The level of serum TNF-α was found to be significantly lower with CSE treatment. CSE was found to be rich in phenol, flavonoids, tocopherol, carotene and phytosteroids. Conclusion The anti-inflammatory and immunomodulatory role of CSE against hapten-induced deleterious DTH inflammation suggests its therapeutic potential in treating inflammatory diseases and combating infections.

Immunomodulatory Effects of Ethanol Extract of Lime Peel on Phagocytosis Activity and Delayed-Type Hypersensitivity Response

The natural human environment is inhabited by various organisms, including those harmful to the body such as bacteria, viruses, fungi, and other pathogens. This condition weakens the immune system's response to pathogens, making the body more susceptible to diseases such as rheumatoid arthritis, cancer, and other inflammations. In some cases, this condition can be fatal, leading to death. This study aims to examine the immunomodulatory effects of Ethanol Extract of Lime Peel on phagocytosis activity and delayed-type hypersensitivity response in experimental animals. The research methods include sample collection and processing, plant identification, extract preparation, and immunomodulatory effect testing. Phytochemical screening results showed the presence of alkaloids, glycosides, flavonoids, tannins, and steroids in the extract of the lime peel. Simplicia and ethanol extract of lime peel characterization yielded results meet the standards of the Indonesian Herbal Pharmacopoeia 2nd edition. Immunomodulatory effect testing was conducted through phagocytosis activity and delayed-type hypersensitivity response assays. The results showed that the extract at doses of 25, 50, and 100 mg/kgBW had immunostimulatory effects in enhancing phagocytosis activity, while doses of 17.5 mg/kgBW, 35 mg/kgBW, and 70 mg/kgBW significantly increased delayed-type hypersensitivity response compared to the negative control. These findings indicate the potential of ethanol extract of Citrus aurantifolia as an immunomodulator that can enhance the body's immune system. This study provides an important contribution to the development of immunomodulatory therapy derived from natural ingredients such as lime peel for managing immunity-related diseases with lower side effects.

Immune Regulation by TNF Receptor-associated Factor 5

The tumor necrosis factor receptor (TNFR)-associated factor (TRAF) family of molecules are intracellular adaptors that regulate cellular signaling through members of the TNFR and Toll-like receptor superfamily. Mammals have seven TRAF molecules numbered sequentially from TRAF1 to TRAF7. Although TRAF5 was identified as a potential regulator of TNFR superfamily members, the in vivo function of TRAF5 has not yet been fully elucidated. We identified an unconventional role of TRAF5 in interleukin-6 (IL-6) receptor signaling involving CD4+ T cells. Moreover, TRAF5 binds to the signal-transducing glycoprotein 130 (gp130) receptor for IL-6 and inhibits the activity of the janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway. In addition, Traf5-deficient CD4+ T cells exhibit significantly enhanced IL-6-driven differentiation of T helper 17 (Th17) cells, which exacerbates neuroinflammation in experimental autoimmune encephalomyelitis. Furthermore, TRAF5 demonstrates a similar activity to gp130 for IL-27, another cytokine of the IL-6 family. Additionally, Traf5-deficient CD4+ T cells display significantly increased IL-27-mediated differentiation of Th1 cells, which increases footpad swelling in delayed-type hypersensitivity response. Thus, TRAF5 functions as a negative regulator of gp130 in CD4+ T cells. This review aimed to explain how TRAF5 controls the differentiation of CD4+ T cells and discuss how the expression of TRAF5 in T cells and other cell types can influence the development and progression of autoimmune and inflammatory diseases.

Antimicrobial and Antiplasmodial Activities of Endophytic Fungi Associated with Psidium guajava

Infections due to antimicrobial-resistant microorganisms have become widespread in recent years. Thus, searching for novel antimicrobial agents to combat such pathogens has become crucial. The current study aimed to evaluate the antimicrobial, antiplasmodial, and immunomodulatory activities of the extracts of endophytic fungi isolated from Psidium guajava. Isolation, identification, fermentation, and extraction of the secondary metabolites of the fungal endophytes were carried out following standard procedures. The extracts were subjected to High-Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) analysis to detect their bioactive components. The Antimicrobial activity and Minimum Inhibitory Concentration of the fungal extracts were evaluated against pure cultures of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumonia using Agar well diffusion and Agar dilution method respectively. The acute toxicity study (LD50) was carried out using Lorke’s method. The extracts were tested in vivo in mice for antiplasmodial activity against Plasmodium berghei and in vitro against Plasmodium falciparum using Peter and Reyley's curative test method and WHO standardized micro-test system with modification respectively. The immunomodulatory activity of the extracts was evaluated by cyclophosphamide-induced myelosuppression (hematological parameters). Active extracts were further subjected to Delayed-Type Hypersensitivity Response (DTHR) and Haemagglutination Inhibition Assay using Sheep Red Blood Cells as antigens. The result showed Alternaria sp. (PGL1, PGL2, PGL3), from P. guajava. The HPLC-DAD analysis revealed the presence of bioactive compounds previously reported to have antimicrobial, antiplasmodial, and immunomodulatory properties. The fungal extracts exhibited varying degrees of antimicrobial activity. The LD50 of the fungi extracts was&gt;5000 mg/kg in mice. The extracts at 100 and 200 mg/kg body weight in mice showed varying degrees of antiplasmodial activity. Growth of P. berghei was significantly (p&lt;0.001) inhibited, curative effect ranges from 59.09 – 100%. Schizont maturation of P. falciparum isolates was inhibited and the highest level of inhibition was observed at 1 mg/ml (p&lt;0.05). The fungal extracts reversed the effect of cyclophosphamide-induced reduction in total white blood cell counts and % neutrophil. This study showed that the tested plant harbors species of endophytic fungi that contain numerous secondary metabolites. The endophytic fungi showed prophylactic, immunostimulatory, and antiplasmodial activities, which can be exploited to develop antimicrobial, antiplasmodial, and immunomodulatory agents.

Chicory root powder included as a prebiotic in different cereal-based diets for dogs: Influences on gut health, metabolic and immunological status

The present experiment was conducted to study the influence of chicory root powder as a prebiotic on gut health, metabolic, and immunological status of dogs fed with different cereal-based diets. Sixteen Labrador dogs, fed either a wheat (WT) or sorghum (SG) based diet, each without (C) or with (P) supplemental chicory root powder at 10 g/kg diet, were divided into four equal groups namely WT-C, WT-P, SG-C and SG-P. The digestibility of DM, OM, and total carbohydrates was significantly (p < 0.05) higher with the SG-C diet than with the other diets. Faecal ammonia was reduced (p = 0.002) in the WT-P group; however, there were no differences (p > 0.05) observed in the faecal pH and contents of lactate, acetate, propionate and total short chain fatty acids (SCFAs). The faecal lactobacilli population was higher (p = 0.001) in both the prebiotic-supplemented groups with a similar trend (p = 0.079) for bifidobacteria. Coliform counts were reduced (p = 0.002) in prebiotic-supplemented diets irrespective of cereals. There were significant (p < 0.05) variations in haemoglobin and haematocrit values among the dietary groups. The delayed-type hypersensitivity response to intradermal phytohemagglutinin (PHA-P) was higher (p<0.001) in both the prebiotic-supplemented groups; a similar trend was evident in the humoral immune response measured as antibody response to sheep erythrocytes. The peripheral lymphocyte subpopulations of CD4+ and CD8+ varied with prebiotic supplementation of the sorghum-based diet. Overall, the findings implies that tailoring the dietary composition to include specific cereals may optimize the beneficial effects of prebiotics in supporting canine health.

Immunomodulatory effects of epiphytic Loranthus micranthus leaf extracts collected from two host plants: Psidium guajava and Parkia biglobosa

BackgroundImmunological abnormalities are implicated in the pathogenesis of many chronic diseases. Due to the drug-related adverse effects of currently available orthodox immunomodulators, natural immunomodulators are being looked upon as potential agents to replace them in therapeutic regimens. This research aimed to investigate the immunomodulatory potential of L. micranthus extracts epiphytic on Psidium guajava (LMPGE) and Parkia biglobosa (LMPBE).MethodsPhytochemical screening and acute toxicity testing were carried out to identify the phytoconstituents and safety profiles of the extracts. The extracts’ innate and adaptive immunomodulatory potentials were determined in experimental animals using in vivo leucocyte mobilization, delayed-type hypersensitivity (DTH) response, hemagglutination antibody titre, and cyclophosphamide-induced myelosuppression models. Levamisole was used as the standard drug throughout the study.ResultsCompared to LMPBE, LMPGE contained significantly (p < 0.05) more tannins, cyanogenic glycosides, saponins, reducing sugars, glycosides, flavonoids, and alkaloids. Furthermore, the groups treated with the extracts had a significant (p < 0.05) increase in the total number of leucocytes, neutrophils, basophils, and antibody titers relative to the untreated control. In the same way, the treatment raised TLC in cyclophosphamide-intoxicated rats, with 250 mg/kg b. w. of LMPGE and LMPBE recording 9712.50 ± 178.00 and 8000.00 ± 105.00 × 109 /L, respectively, compared to 3425.00 ± 2 5.00 × 109 /L in the untreated group. Overall, LMPGE was more effective.ConclusionsThe findings from this study suggest that L. micranthus epiphytic in Psidium guajava and Parkia biglobosa has possible immune stimulating potential.

The immunostimulatory effects of fucoidan on the cellular and humoral immune response in Wistar rats.

Natural product active ingredients are currently being studied rigorously worldwide and offer a viable substitute for traditional immunotherapy for various medical disorders. The objective of the study was to investigate the immunostimulatory properties of fucoidan in albino Wistar rats. For the current study, forty rats were divided into five groups of rats that were used in good condition. In-vivo experiments of fucoidan were carried out in Wistar albino rats, such as the cyclophosphamide-caused myelosuppression, the delayed-type hypersensitivity (DTH) response, the phagocytic activity, the haemagglutinating antibody (HA) titer, and the neutrophil adhesion test. The phagocytic index increased significantly in response to Fucoidan in a dose-dependent manner, as well as enhanced DTH reaction, and HA titer caused by sheep red blood cells sheep red blood cells. Additionally, fucoidan decreased myelosuppression in rats after cyclophosphamide treatment and enhanced neutrophil adhesion with nylon fiber. These findings imply that fucoidan has immunostimulant properties and could potentially utilised to treat immune-depression diseases.

Comparative analysis of the effects of cyclophosphamide and dexamethasone on intestinal immunity and microbiota in delayed hypersensitivity mice.

The T cell-mediated delayed-type hypersensitivity (DTH) response is critical for elucidating cellular immune mechanisms, especially the role of memory T cells upon antigen re-exposure. This study aimed to investigate the specific effects of the immunosuppressive drugs Cyclophosphamide (CY) and Dexamethasone (DEX) on intestinal immunity and microbiota in a DTH mouse model, contributing to a more nuanced understanding of their immunomodulatory mechanisms. Female BALB/c mice were sensitized to 2,4-dinitrofluorobenzene (DNFB) and randomly allocated into control, CY, and DEX groups. The impact of CY and DEX on immune function was assessed through measurement of thymus and spleen indices, lymphocyte proliferation in mesenteric lymph nodes (MLNs) using MTT assay, and flow cytometric analysis of T cell subsets and TCR expression. Intestinal secretory IgA (sIgA) was quantified by ELISA, and gut microbiota diversity was evaluated using 16S rRNA gene sequencing. CY and DEX significantly reduced the immune function in DNFB-induced sensitized mice, as indicated by decreased thymus and spleen indices, MLN enlargement, intestinal sIgA content, and ear swelling degree. Flow cytometry revealed that CY increased the proportion of total CD3+ T cells but reduced CD3+CD69+ activated T cells and CD3+TCRγ/δ+ T cells, while DEX increased CD3+CD4+ helper T cells. Both drugs induced distinct changes in gut microbiota diversity and structure, with CY enhancing α diversity and DEX reducing it. The study demonstrates that CY and DEX have distinct regulatory effects on the immune organ index, distribution of T cell subsets, and diversity and structure of gut microbiota on DTH-induced immune responses mice, suggesting their differential influence on intestinal mucosal immunity. These findings have implications for the development of targeted immunotherapies and understanding the interplay between immunosuppressive drugs and gut microbiota.

In Vitro and In Vivo Methods for Analysis of Nanoparticles' Potential toInduce Delayed-Type Hypersensitivity Reactions.

Delayed-type hypersensitivity (DTH) reactions are among the common reasons for drug withdrawal from clinical use during the post-marketing stage. Several in vivo methods have been developed to test DTH responses in animal models. They include the local lymph node assay (LLNA) and local lymph node proliferation assay (LLNP). While LLNA is instrumental in testing topically administered formulations (e.g., creams), the LLNP was proven to be predictive of drug-mediated DTH in response to small molecule pharmaceuticals. Global efforts in reducing the use of research animals lead to the development of in vitro models to predict test-materials' mediated DTH. Two such models include theanalysis of surface marker expression in human cell lines THP-1 and U-937. These tests are known as the human cell line activation test (hCLAT) and myeloid U937 skin sensitization test (MUSST or U-SENS), respectively. Here we describe experimental procedures for all these methods, discuss their in vitro-in vivo correlation, and suggest a strategy for applying these tests to analyze engineered nanomaterials and nanotechnology-formulated drug products.