Evaluation of immunomodulatory potential of probiotic conditioned medium on murine macrophages

Probiotics are a mixture of beneficial live bacteria and/or yeasts that naturally exist in our bodies. Recently, numerous studies have focused on the immunostimulatory effects of single-species or killed multi-species probiotic conditioned mediums on macrophages. This study investigates the immunostimulatory effect of commercially available active, multi-species probiotic conditioned medium (CM) on RAW264.7 murine macrophages. The probiotic CM was prepared by culturing the commercially available probiotic in a cell-culture medium overnight at 37 °C, followed by centrifugation and filter-sterilization to be tested on macrophages. The immunostimulatory effect of different dilution percentages (50%, 75%, 100%) of CM was examined using the MTT assay, proinflammatory cytokine (tumor necrosis factor TNF-alpha) production in macrophages, migration, and phagocytosis assays. For all the examined CM ratios, the percentages of cell viability were > 80%. Regarding the migration scratch, TNF-alpha and phagocytosis assays, CM demonstrated a concentration-dependent immunostimulatory effect. However, the undiluted CM (100%) showed a significant (p-value < 0.05) stimulatory effect compared to the positive and negative controls. The findings suggest that the secretions and products of probiotics, as measured in the CM, may be closely associated with their immune-boosting effects. Understanding this relationship between probiotic secretions and immune function is crucial for further exploring the potential benefits of probiotics in enhancing overall health and well-being.

Structure-activity relationship of fucoidans and alginates obtained from Cystoseira indica in a biorefinery concept

A sequential extraction process was employed to isolate fucoidan and alginate from brown seaweed Cystoseira indica. Extraction process was designed to evaluate the effects of acid concentrations (0.025, 0.05, 0.1 and 0.2 M HCl) and temperatures (room temperature, 60 °C and 80 °C) on sensory, structural and immunostimulatory properties of fucoidans and following results on Na+-alginates. The amounts of isolated fucoidans (0.193-0.658 g/5 g powder) and Na+-alginates (2.877-3.383 g/ 5 g powder) greatly varied among different extractions. Fucoidans were composed of neutral sugars, mainly fucose (15.74-47.64 %) and galactose (18.66-26.88 %) units, with varying amounts of sulfates (8.76-12.40 %) and uronic acids (0.46-8.90 %). The weight average molecular weights (Mw) of fucoidans (234.6-1990.0 × 103 g/mol) and Na+-alginates (358.4-2318.3 × 103 g/mol) were closely controlled by extraction condition. Both fucoidan and Na+-alginate molecules noticeably induced RAW264.7 murine macrophage cells to exert proinflammatory response, producing considerable levels of NO, IL-1β, TNF-α and IL-6 through NF-κB and MAPKs signaling pathways. Altogether, extraction process of fucoidan not only exerted determining effect on its structure and cell activation capacity, but also influenced the quality of Na+-alginate obtained in the next step.

Comparison of immunotherapy mediated by apoptotic bodies, microvesicles and exosomes: apoptotic bodies' unique anti-inflammatory potential

Immunotherapy, including immunostimulation and immunosuppression, has seen significant development in the last 10 years. Immunostimulation has been verified as effective in anti-cancer treatment, while immunosuppression is used in the treatment of autoimmune disease and inflammation. Currently, with the update of newly-invented simplified isolation methods and the findings of potent triggered immune responses, extracellular vesicle-based immunotherapy is very eye-catching. However, the research on three main types of extracellular vesicles, exosomes, microvesicles and apoptotic bodies, needs to be more balanced. These three subtypes share a certain level of similarity, and at the same time, they have their own properties caused by the different methods of biogensis. Herein, we summarized respectively the status of immunotherapy based on each kind of vesicle and discuss the possible involved mechanisms. In conclusion, we highlighted that the effect of the apoptotic body is clear and strong. Apoptotic bodies have an excellent potential in immunosuppressive and anti-inflammatory therapies .

Four polysaccharides isolated from Poria cocos mycelium and fermentation broth supernatant possess different activities on regulating immune response

Four polysaccharide fractions were isolated and purified from the culture supernatant and mycelium of Poria cocos, and differences in their immunomodulatory activity were investigated. The average molecular weights of EPS-0M, EPS-0.1M, IPS-0M, and IPS-0.1M were 1.77 × 10³, 2.01 × 10³, 0.03 × 10³ and 4.97 × 10³ kDa, respectively. They all mainly consisted of 5 monosaccharides, including glucose, mannose, galactose, fucose and rhamnose, but with different molar ratios. At a dose of 50 μg/mL, EPS-0M, EPS-0.1M, and IPS-0.1M significantly increased the production of nitric oxide (NO), as well as the mRNA and protein levels of pro-inflammatory factors including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in RAW264.7 cells, suggesting that they enhanced macrophage-mediated innate immunity. Moreover, based on the in vitro inflammation model of lipopolysaccharide (LPS)-stimulated RAW264.7 cells, EPS-0M, EPS-0.1M and IPS-0M but not IPS-0.1M could inhibit the LPS-induced excessive inflammatory response, including NO, IL-6, TNF-α, IL-1β production and gene transcription. Interestingly, IPS-0M showed a relatively poor immunostimulatory effect, but had the strongest inhibitory effect against the LPS-induced RAW264.7 inflammatory response. Furthermore, our results indicate that the nuclear factor-kappa B (NF-κB) pathway is associated with the immunomodulatory effects of the polysaccharide samples on RAW264.7 cells. This study can provide a reference for the more targeted application of different polysaccharide components from Poria cocos for human health.

Structural characterization, and in vitro immunostimulatory and antitumor activity of an acid polysaccharide from Spirulina platensis

In this study, a novel heteropolysaccharide named SP90-1 with immunostimulatory and antitumor activity was purified and characterized from Spirulina platensis. SP90-1 has a molecular weight of 63.92 kDa and mainly consists of rhamnose (Rha), glucose (Glc), galactose (Gal) and glucuronic acid (GlcA), followed by the minor components Fuc and Xyl. The backbone of SP90-1 was determined to be →2)-α-d-Rhap-(1 → 2,3)-α-d-Rhap-(1 → 4)-β-d-Glcp-(1 → [3)-β-d-Rhap-(1→]₃, with branches at the O-3 of Rha, consisting of the side chains 4-Galp and 4-GlcpA. SP90-1 was found to significantly enhance phagocytic capacity, promote the secretion of nitric oxide (NO), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in RAW264.7 cells, and remarkably inhibit the growth of A549 lung cancer cells. These findings demonstrate that SP90-1 could potentially be further explored for immunomodulatory biomedical applications.

Polysaccharide extracted from Taraxacum platycarpum root exerts immunomodulatory activity via MAPK and NF-κB pathways in RAW264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Taraxacum platycarpum Dahlst. (Korean dandelion) is a medicinal herb used in traditional medicine in Korea to treat various disease such as furuncles, mammitis, hepatitis, jaundice. Moreover, a decoction prepared from T. platycarpum leaves and stems is an effective treatment for cancer, glycosuria, liver disease, pleurodynia, and stomach problems.

AIM OF THE STUDY

The main objective of this work was to study the composition and structural properties of polysaccharides (TPP) from Taraxacum platycarpum Dahlst. root and investigate the immunostimulatory activity on RAW264.7 cells.

MATERIALS AND METHODS

TPP was extracted from T. platycarpum using hot water extraction, ethanol precipitation method and its fractionated using DEAE-Sepharose fast flow column. The composition, molecular weight, and structural characterization of TPP and its fractions were evaluated by various techniques. Further, the immunostimulatory activity of polysaccharides was tested on murine macrophage cell line RAW264.7 by various in vitro assays. The structure effect of TPP on RAW264.7 cells was studied by the removal of sulfate (desulfation) and protein (deproteinization) contents from TPP.

RESULTS

We obtained three fractions namely TPP-1, TPP-2, and TPP-3 which mainly consisted of carbohydrates (75.55, 52.71, and 48.41%), sulfate (8.42, 15.19, and 27.67%), uronic acid (1.27, 6.56, and 4.39%), and protein (8.15, 24.85, and 9.73%). The average molecular weight of the fractions was 56.7, 108.2, and 132.3 × 10³ g/mol, respectively. The polysaccharides activate the RAW264.7 cell to produce a significant amount of NO and upregulate the various mRNA expression by the activation of MAPK and NF-κB pathways via TLR4, TLR2, and CR3 receptors. The structurally modified deproteinated derivative (DP-TPP-2) more effectively decreases the NO production which means the protein content of TPP-2 mainly contributes to the RAW264.7 cells activation. The structure of DP-TPP-2 primarily consists of 1 → 2)-Galp, 1 → 6)-Glup, 1 → 2) - Rhap, and 1 → 5) - Arap glycosidic linkages.

CONCLUSIONS

The present study demonstrated that the polysaccharide isolated from T. platycarpum shows admirable immunostimulatory by the activation of MAPK and NF-κB pathways through TLR4, TLR2, and CR3 receptors. The protein content of polysaccharides mainly contributes to the RAW264.7 cells activation. Our study results could be useful for developing a new immunostimulant agent.

Heterologous expression and characterization of a novel glycoside hydrolase family 55 β-1,3-glucanase, AcGluA, from Archangium sp. strain AC19

Some microbial-associated molecular patterns (MAMPs), like glucan oligosaccharides, can be recognized by pattern recognition receptors (PRRs) of plant to elicit further immunity response. In this study, a novel glycoside hydrolase family 55 β-1,3-glucanase (AcGluA) from Archangium sp. strain AC19 was cloned and expressed in Escherichia coli. Among the reported β-1, 3-glucanases from the glycoside hydrolase 55 family, the purified AcGluA exhibited the highest activity on laminarin at pH 6.0 and 60 °C with 112.3 U/mg. Activity of AcGluA was stable in the range of pH 4.0-9.0 and at temperatures below 60 °C. The K_m and V_max of AcGluA for laminarin were 3.5 mg/ml and 263.5 μmol/(ml·min). AcGluA hydrolyzed laminarin into a series of oligosaccharides, suggesting it was an endo-β-1,3-glucanase. The high dose of oligosaccharides (1600 mg/l) had conspicuous biocontrol efficacy on the defense of rice seedlings to Magnaporthe oryzae, which provided a new idea for the development of green biopesticide.Key points• The AcGluA was determined bacteria-derived β-1,3-glucanases in the GH55 family.• The AcGluA showed the highest activity towards laminarin among reported GH55 family.• The hydrolysates of laminarin showed conspicuous biocontrol efficacy to M. oryzae.

In vivo immunostimulatory effect of the amoebocyte lysate and plasma of Asian horseshoe crab, Tachypleus gigas in a piscine model

Antimicrobial proteins/peptides are becoming a new generation of immunostimulants for prevention and disease control in human and animals, including aquatic animals. As the haemolymph of horseshoe crabs (Tachypleus) contains broad ranges of bioactive compounds, we have explored the in vivo immunostimulating potential of amoebocyte lysate and plasma using a fish model. Indian major carp, Labeo rohita, yearlings were injected intraperitoneally with two doses of lysate and plasma at 50 and 100 µg protein per fish. No abnormalities and/or mortalities were recorded in any group. L. rohita injected with 50 µg lysate and 100 µg plasma protein showed significant enhancement (P < 0.01) of various haematological and immunological parameters. There was a significant rise in the total protein and globulin content, myeloperoxidase and respiratory burst activity following injection with 50 µg lysate and 100 µg plasma protein. The agglutinating and haemagglutinating activities were increased albeit not significantly (P > 0.01) in any groups. On the contrary, a significantly high hemolysin titre was recorded in fish that received 100 µg plasma protein. Following challenge with Aeromonas hydrophila, both lysate and plasma protein(s) cross protected the fish after 30 days. The highest survival (50%) was recorded in group injected with 50 µg lysate protein, followed by 45% in both 100 µg lysate and plasma protein injected groups.

Immunostimulatory effects of the intracellular polysaccharides isolated from liquid culture of Ophiocordyceps sinensis (Ascomycetes) on RAW264.7 cells via the MAPK and PI3K/Akt signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Chinese Cordyceps (DongChong XiaCao), a parasitic complex of a fungus Ophiocordyceps sinensis and a caterpillar, is a traditional Chinese medicine. Polysaccharides extracted from O. sinensis have immunomodulatory effects on macrophages. However, the mechanism of polysaccharides on macrophage and the composition of polysaccharides are not known.

AIM OF STUDY

We aimed to investigate composition and structure of the intracellular polysaccharides from O. sinensis mycelia (designed as OSP), and evaluate its the immunomodulatory effect on macrophages and its underlying mechanism.

MATERIALS AND METHODS

We performed a liquid-state fermentation of O. sinensis to produce mycelia. The DEAE-Sephadex-A25 cellulose column and Sephadex-G100 gel column chromatography were employed to purify and character the intracellular OSP. Macrophages RAW264.7 cells were employed to evaluate OSP's immunomodulatory activity and the possible mechanism responsible for the activation of macrophages in vitro.

RESULTS

The average molecular weight of OSP was distributed at 27,972 Da, OSP was composed of xylose, mannose, glucose, and galactose with the ratio of 2.9 : 6.6 : 166 : 2.6, with a trace amount of fucose, arabinose and rhamnose. The phagocytosis of RAW264.7 cells was improved significantly and remarkable changes were observed in the morphology with OSP-treated cells. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis demonstrated that OSP had an ability to regulate the mRNA expression of pro-inflammatory and anti-inflammatory cytokines, and to induce the mRNA expression level of iNOS in a concentration dependent manner in RAW264.7 cells. Western blotting analysis showed that the regulation of NO and cytokines was mediated through mitogen-activated protein kinase (MAPK) and PI3K/Akt signaling pathways.

CONCLUSION

This study demonstrated that OSP was with a capacity to activate macrophage cells RAW264.7 for an improvement of immunomodulation activities, which was through regulation of inflammatory mediators via MAPK and PI3K/Akt signaling pathways.

Immunomodulatory sulfated polysaccharides from Caulerpa racemosa var. peltata induces metabolic shifts in NF-κB signaling pathway in RAW 264.7 macrophages

Algal polysaccharide activates macrophages to alter physiologic biomarkers to drive the immunomodulatory phenotype, but it lacks specific biomarkers involved in the biochemical underpinning process. Here, we undertook an extensive analysis of the RAW 264.7 macrophages induced by an immunostimulating sulfated polysaccharide from Caulerpa racemosa var. peltata (CRVP-1) employing combined transcriptomic, proteomic, and metabolomic analyses to reveal the molecular details occurring in the CRVP-1-induced immunomodulatory process. The omics profiling of CRVP-1-activated macrophage demonstrated a total of 8844 genes (4354 downregulated and 4490 upregulated), 1243 proteins (620 downregulated and 623 upregulated), and 68 metabolites (52 downregulated and16 upregulated). Further, the co-mapped correlation network of omics combined with Western blot and immunofluorescence staining indicated that the cluster of differentiation 14 (CD14) might assist Toll-like receptor 4 (TLR4) involved in nuclear factor kappa-B (NF-κB) signaling pathway to drive the immunomodulatory phenotype. Together, our results discover novel physiologic biomarkers in the immunomodulatory activities of algal polysaccharides.

Purification, characterization and immunostimulatory effects of polysaccharides from Anemarrhena asphodeloides rhizomes

The crude polysaccharide was extracted from A. asphodeloides rhizomes and further purified to produce two fractions F₁ (50.0%) and F₂ (19.6%). The chemical constitutions of the polysaccharides were neutral sugars (51.4%-89.7%), uronic acids (1.0%-30.2%) and sulfate esters (3.4%-8.1%), with various ratios of monosaccharides including rhamnose (1.4%-6.1%), arabinose (7.1%-21.2%), xylose (0.2%-4.8%), mannose (39.9%-79.0%), glucose (6.0%-11.1%) and galactose (2.6%-22.0%). The molecular properties of the polysaccharides were investigated by the HPSEC-UV-MALLS-RI system, revealing the M_w 130.0 × 10³-576.5 × 10³ g/moL, R_g 87.6-382.6 nm and SV_g 0.3-54.3 cm³/g. The polysaccharides stimulated RAW264.7 cells to produce considerable amounts of NO and up-regulate the expression of TNF-α, IL-1 and COX-2 genes. Polysaccharides exhibited the growth inhibitory effects on cancer cells lines of AGS, MKN-28 and MKN-45, in which F₂ fraction exhibited prominent bioactivities. The AGS cells treated with F₂ experienced condensed cytoplasm, shrinkage of nucleus and chromatin marginalization with the highest number of cells at early-stage apoptosis reaching 54.6%. The inhibitory effect of F₂ polysaccharide on AGS cells was through MAPKs and STAT3 signaling pathways. The backbone of the F₂ was mainly linked by (1 → 4)-linked mannopyranosyl and (1 → 3)-linked galactopyranosyl. Taken together, the polysaccharide from A. asphodeloides rhizomes could be utilized as medicinal, pharmacological and functional food ingredients.

Comprehensive analysis of oral administration of Vitamin E on the early stage of Trypanosoma brucei brucei infection

Reinforcement of the body with exogenous antioxidants have been shown to mitigate the negative effects of African trypanosomiasis on the host and contribute greatly to their survival. This study was therefore conducted to evaluate the effects of oral administration of Vitamin E on the early stage of Trypanosoma brucei brucei infection. To achieve this, parasite free healthy rats were acclimatized for 2 weeks before they were divided into three groups. Two of the groups were infected by intraperitoneal inoculation of 1 × 10⁴ parasites/rat and monitored for the presence of Trypanosoma brucei brucei. Blood samples were collected from the infected rats from the second day post infection to detect the presence of parasites. Vitamin E treatment started day 4 post infection at the onset of parasitaemia. Parasites were monitored till the end of the study. The blood glucose level was determined using a glucometer; the lipid profile, liver and kidney biomarkers, electrolytes and protein were determined by colorimetric method using commercial kits. Haematological parameters were analysed using a sysmex haematology analyser. The results of this study showed that the infection adversely affected the biomarkers examined showing its negative effect on liver, kidney, haematological parameters and host electrolyte balance. Treatments with Vitamin E was however able to mitigate the negative effect of this infection. In conclusion, the treatment was able to ameliorate the anaemia and organ damage caused by Trypanosoma brucei brucei, extend the life span of the treated rats and greatly delay the time taken to get to the second stage of the infection.

Purification, structural analysis and mechanism of murine macrophage cell activation by sulfated polysaccharides from Cystoseira indica

Sulfated polysaccharides were isolated and purified from the water extract of Cystoseira indica using DEAE Sepharose Fast Flow column to evaluate their structure and macrophage stimulating capacity. Crude and fractionated polysaccharides, CIF1 and CIF2, were mostly composed of neutral sugars (73.1%-78.6%) with relatively lower amounts of acidic sugars (1.3%-9.0%) and sulfate esters (6.9%-9.7%). The polymer chains of polysaccharides were mainly built of different levels of glucose (2.1%-30.8%), fucose (17.2%-24.4%), mannose (17.8%-20.6%) and galactose (16.7%-17.3%). The weight average molecular weight (Mw) of polysaccharides varied between 573.1 × 103 g/mol to 1146.6 × 103 g/mol. The CIF2 polysaccharide, as the most immunostimulating polysaccharide, remarkably induced the release of nitric oxide and inflammatory cytokines including TNF-α, IL-1β, IL-6 and IL-10 from RAW264.7 murine macrophage cells through NF-κB and PAMKs transduction signaling pathways via cell surface TLR4. The interconnections of sugars in CIF2 polysaccharide were complex with (1→3)-fucopyranose, (1→2,3,4)-glucopyranose, (→1)-galactopyranose, (→1)-xylopyranose, (1→2)-rhamnopyranose and (1→2,3)-mannopyranose units being the most predominant residues.

Isolation, purification, and characterization of novel polysaccharides from lotus (Nelumbo nucifera) leaves and their immunostimulatory effects

In this study, a crude water-soluble polysaccharide (LLWP-C) was extracted from lotus leaves and further purified by size exclusion chromatography, to obtain the two main polysaccharides, LLWP-1 and LLWP-3. Physical and chemical analyses showed that they were homogeneous polysaccharides in β-type glycosidic linkage. LLWP-1 was devoid of helical conformation, had a molecular weight of 85.1 kDa and was mainly composed of Rha, Ara, Gal, Glu, and GalA in a molar ratio of 7.0:24.8:28.0:6.0:26.4. LLWP-3 showed a helical conformation, had a molecular weight of 12.5 kDa and consisted mainly of Rha, Ara, Gal, Glu, Man, and GalA in a molar ratio of 6.6:9.8:15.0:8.9:6.1:47.2. It was demonstrated that LLWP-C and both purified LLWP-1 and LLWP-3 could effectively enhance the proliferation, phagocytosis, nitric oxide (NO), and cytokine secretions by activating corresponding mRNA expression in macrophages, via MAPK and NF-κB pathways. LLWP-3 displayed the greatest immunostimulatory potential, followed by LLWP-1 and LLWP-C. These findings suggest that polysaccharides extracted from lotus leaf exert immunostimulatory activity that could be further investigated to develop functional foods and natural immunopotentiating therapeutic agents.

Stimulating T Cells Against Cancer With Agonist Immunostimulatory Monoclonal Antibodies

Elimination of cancer cells through antitumor immunity has been a long-sought after goal since Sir F. Macfarlane Burnet postulated the theory of immune surveillance against tumors in the 1950s. Finally, the use of immunotherapeutics against established cancer is becoming a reality in the past 5years. Most notable are the monoclonal antibodies (mAbs) directed against inhibitory T-cell receptors cytotoxic T lymphocyte antigen-4 and programmed death-1. The next generation of mAbs targeting T cells is designed to stimulate costimulatory receptors on T cells. Here we review the recent progress on these immunostimulatory agonist antibodies against the costimulatory receptors CD137, GITR, OX40, and CD27.

High potency of lipid conjugated TLR7 agonist requires nanoparticulate or liposomal formulation

Conjugation of small molecule agonists of Toll-like receptor 7 (TLR7) to proteins, lipids, or polymers is known to modulate potency, and the physical form or formulation of these conjugates is likely to have a major effect on their immunostimulatory activity. Here, we studied the effect of formulation on potency of a 1,2‑di‑(9Z‑octadecenoyl)‑sn‑glycero‑3‑phosphoethanolamine (DOPE) conjugated TLR7 agonist (DOPE-TLR7a) alongside assessing physical form using Dynamic Light Scattering (DLS), Nanosight Particle Tracking (NTA) analysis and Small Angle X-ray Scattering (SAXS). A very high potency of DOPE-TLR7a conjugate (EC₅₀ around 9 nM) was observed either when prepared by direct dilution from DMSO or when formulated into 400-700 nm large multilamella liposomes containing dimethyldioctadecylammonium bromide salt (DDA) and DOPE. When prepared by dissolution in DMSO followed by dilution in aqueous culture medium, 93 ± 5 nm nanoparticles were formed. Without dilution from solution in DMSO, no nanoparticles were observed and no immunostimulatory activity could be detected without this formulation step. SAXS analysis of the conjugate after DMSO dissolution/water dilution revealed a lamellar order with a layer spacing of 68.7 Å, which correlates with arrangement in groups of 3 bilayers. The addition of another immunostimulatory glycolipid, trehalose‑6,6‑dibehenate (TDB), to DOPE:DDA liposomes gave no further increase in immunostimulatory activity beyond that provided by incorporating DOPE-TLR7a. Given the importance of nanoparticle or liposomal formulation for activity, we conclude that the major mechanism for increased potency when TLR7 agonists are conjugated to macromolecules is through alteration of physical form.

Anti-Inflammatory and Immunostimulatory Activities of Astragalosides

Astragalus membranaceus (Fisch) Bge (Huang-Qi) is a well-known herbal medicine with tonic property and has been widely used to treat cancer and other immune disorders in China and Southeast Asia for thousands of years. Accumulating evidence suggests that Huang-Qi possesses both immune-boosting and anti-inflammatory/immune-regulatory effects clinically, leaving the mechanism elusive. Recently, we discovered that Astragaloside (ASI), a major active component of Huang-Qi, is able to increase CD45 phosphatase activity. In this paper, we reviewed the recent progress of ASIs in immunoregulatory and anti-inflammatory activities, including the induction of T-cell activation, regulation of effector/regulatory T-cell balance, enhancement of CD45 phosphatase activity, inhibition of pro-inflammatory cytokine and, NF-[Formula: see text]B pathway. Finally, we hypothesized that inducing interferon-[Formula: see text] (IFN-[Formula: see text]) activity by activating CD45 protein tyrosine phosphatase (PTPase) may be involved in the protective role of ASI in two contrary immune-associated diseases. These pharmacological properties highlight the traditional uses of Astragalus and provide a new direction for subsequent research and the clinical application of this traditional herbal.

LongoVital- An Imminent Therapeutic Modality: An Unseen Drug Review with Advanced Features and Hypothesis

Herbal medication still happens to be the backbone of the major world's population essentially because of the assumption that these drugs are free of any side effects and easily available. LongoVital (LV) is a herbal preparation with documented immune-modulatory and immune-stimulatory effects in man. Various studies conducted to date, have shown LV to have prolonged and beneficial impact in the treatment of orofacial diseases, when administered in recommended daily doses. With its combined antimicrobial and immunostimulatory effects, LV can be regarded as an emerging therapeutic modality in the treatment of orofacial diseases.

Immunostimulatory potential and proteome profiling of Leishmania donovani soluble exogenous antigens

Isolation of the soluble exogenous antigens (SEAgs), its immune response study and proteome profiling is an essential prerequisite for understanding the molecular pathogenesis of Leishmania donovani. The immunostimulatory potential of L. donovani SEAgs, purified from culture of L. donovani clinical isolate, was evaluated for their ability to induce cellular responses in treated/cured hamsters. SEAgs induced significant proliferative responses in lymphocytes (SI 5.6 ± 2.3; P < 0.01) isolated from cured hamster. In addition, significant NO production in response to SEAgs was also noticed in macrophages of hamsters, mouse and human cell lines (J774A-1 and THP1). Western blot analyses with antibodies against proteophosphoglycan (PPG; surface-expressed and secreted molecule) of L. donovani revealed that PPG molecules are also present in L. donovani SEAgs. Mass spectrometry (MS)-based proteome analysis of 12 protein bands of SEAgs through MALDI-TOF/TOF endorsed the identification of some Th1-stimulatory immunogenic proteins. These immunogenic proteins may offer increased hope for the discovery of new promising vaccine candidates against visceral leishmaniasis (VL). The overall results suggest that immunostimulatory molecules are present in the SEAgs, which may be further exploited, for developing a subunit vaccine against VL a fatal human disease.

An engineered Fc variant of an IgG eliminates all immune effector functions via structural perturbations

The Fc variant of IgG2, designated as IgG2σ, was engineered with V234A/G237A /P238S/H268A/V309L/A330S/P331S substitutions to eliminate affinity for Fcγ receptors and C1q complement protein and consequently, immune effector functions. IgG2σ was compared to other previously well-characterized Fc 'muted' variants, including aglycosylated IgG1, IgG2m4 (H268Q/V309L/A330S/P331S, changes to IgG4), and IgG4 ProAlaAla (S228P/L234A/L235A) in its capacity to bind FcγRs and activate various immune-stimulatory responses. In contrast to the previously characterized muted Fc variants, which retain selective FcγR binding and effector functions, IgG2σ shows no detectable binding to the Fcγ receptors in affinity and avidity measurements, nor any detectable antibody-dependent cytotoxicity, phagocytosis, complement activity, or Fc-mediated cytokine release. Moreover, IgG2σ shows minimal immunogenic potential by T-cell epitope analysis. The circulating half-life of IgG2σ in monkeys is extended relative to IgG1 and IgG2, in spite of similar in vitro binding to recombinant FcRn. The three-dimensional structure of the Fc, needed for assessing the basis for the absence of effector function, was compared with that of IgG2 revealing a number of conformational differences near the hinge region of the CH2 domain that result from the amino acid substitutions. Modeling reveals that at least one of the key interactions with FcγRs is disrupted by a conformational change that reorients P329 to a position that prevents it from interacting with conserved W90 and W113 residues of the FcγRs. Inspection of the structure also indicated significant changes to the conformations of D270 and P329 in the CH2 domain that could negatively impact C1q binding. Thus, structural perturbations of the Fc provide a rationale for the loss of function. In toto, these properties of IgG2σ suggest that it is a superior alternative to previously described IgG variants of minimal effector function, for future therapeutic applications of non-immunostimulatory mAb and Fc-fusion platforms.