Immunoenhancing Properties Research Articles

The Polysaccharides from Pinellia ternata and Their Derivatives: Preparation, Structure Characteristics, and Activities in Vitro.

Three polysaccharides, PTC, PTH, and PTB, were extracted from Pinellia ternata using three different extraction conditions: room temperature water, hot water, and 2 % Na2CO3 solution. PTC and PTH were composed of rhamnose, glucose, galactose, mannose, glucuronic acid, galacturonic acid, and arabinose, which combine to form complex structures. PTB was composed solely of glucose and rhamnose. Further analysis indicated that PTC and PTB exhibited triple-helix structures. PTC showed the highest scavenging capacity against DPPH, superoxide anion, and hydroxyl radicals, with half maximal inhibitory concentrations (IC50) of 1004.1, 1584.1, and 1584.1 μg/mL, respectively. Additionally, PTC, PTH, and PTB were subjected to sulfation, phosphorylation, and selenization, resulting in the production of nine derivates. The distinctive absorptive bands of these derivates were determined through infrared spectroscopy. Selenized and sulfated derivates have shown significant antitumor and immunoenhancing properties. Our findings revealed that at 400 μg/mL, the inhibition rate of selenated PTB on HeLa cells was 54.2 % and that on HepG2 cells was 43.1 %. Additionally, selenized PTC displayed significant immunoenhancing activity, with a proliferation rate of 63.7 % at 400 μg/mL in RAW264.7 cells. These results provide valuable evidence supporting the consideration of polysaccharides from Pinellia ternata as a potential candidate for the development of antineoplastic drugs.

Immunoenhancing and antioxidant potentials of kimchi, an ethnic food from Korea, as a probiotic and postbiotic food

Kimchi, the traditional lactic fermented vegetables from Korea, is globally praised for its potential as a functional food owing to the presence of beneficial microorganisms known as probiotics. However, the serving of kimchi in traditional Korean dishes often involves cooking at high temperature, thus killing the probiotics. Recently, non-viable or inactivated microorganisms and their metabolites, known as postbiotics, were shown to confer health benefits when consumed, thus giving rise to a novel potential of kimchi as a postbiotic food with health functionalities. The present study aimed to explore the potential of uncooked and cooked kimchi, both as a probiotic and postbiotic food, respectively, using an animal model. Mice were fed by AIN-76 diet enriched in 10% freeze-dried uncooked or cooked kimchi for 28 days prior to kill. Several parameters related to immune system and antioxidant were evaluated. Exposure of kimchi toward heat in steaming process killed the microorganisms in kimchi, but did not alter its antioxidant activity. Interestingly, the consumption of uncooked and cooked kimchi stimulated the growth of lactic acid bacteria in the intestine indifferently, as shown in the fecal matter. In addition, kimchi supplementation, either uncooked or cooked, increased the number of splenic lymphocytes and intestinal IgA, supporting the role of kimchi in the immune system. Furthermore, kimchi supplementation reduced the level of lipid peroxidation in the fecal matter, indicating its antioxidant activity in vivo. Taken together, the findings in this study suggest the potential of kimchi both as a probiotic and postbiotic food with antioxidant and immunoenhancing properties.

Injectable Hydrogel Mucosal Vaccine Elicits Protective Immunity against Respiratory Viruses.

Intranasal vaccines, eliciting mucosal immune responses, can prevent early invasion, replication, and transmission of pathogens in the respiratory tract. However, the effective delivery of antigens through the nasal barrier and boosting of a robust systematic and mucosal immune remain challenges in intranasal vaccine development. Here, we describe an intranasally administered self-healing hydrogel vaccine with a reversible strain-dependent sol-gel transition by precisely modulating the self-assembly processes between the natural drug rhein and aluminum ions. The highly bioadhesive hydrogel vaccine enhances antigen stability and prolongs residence time in the nasal cavity and lungs by confining the antigen to the surface of the nasal mucosa, acting as a "mucosal mask". The hydrogel also stimulates superior immunoenhancing properties, including antigen internalization, cross-presentation, and dendritic cell maturation. Furthermore, the formulation recruits immunocytes to the nasal mucosa and nasal-associated lymphoid tissue (NALT) while enhancing antigen-specific humoral, cellular, and mucosal immune responses. Our findings present a promising strategy for preparing intranasal vaccines for infectious diseases or cancer.

Structural Characterization and Immunoenhancing Properties of Polysaccharide CPTM-P1 from Taxus media.

Polysaccharides extracted from Taxus media hrough an aqueous method were further refined by removing proteins via the Sevag technique and purified by dialysis. The separation of these polysaccharides was accomplished using a DEAE-cellulose chromatog-raphy column, yielding two distinct fractions, named CPTM-P1 and CPTM-P2. Notably, CPTM-P1 emerged as the primary polysaccharide component within Taxus media. Consequently, a comprehensive analysis focusing exclusively on CPTM-P1 was undertaken. The molecular weight of CPTM-P1 was established through gel permeation chromatography (GPC), and its monosaccharide composition was deciphered using HPLC-MS. The structure was further elucidated through nuclear magnetic resonance (NMR) spectroscopy. The molecular weight of CPTM-P1 was determined to be 968.7 kDa. The monosaccharide composition consisted of galactose (Gal), arabinose (Ara), galacturonic acid (Gal-UA), glucose (Glc), rhamnose (Rha), xylose (Xyl), mannose (Man), fucose (Fuc), glucuronic acid (Glc-UA), and ribose (Rib). The proportional distribution of these components was 30.53%, 22.00%, 5.63%, 11.67%, 11.93%, 1.69%, 8.50%, 1.23%, 5.63%, and 1.17%, respectively. This confirmed CPTM-P1 as an acidic heteropolysaccharide with a glycuronic acid backbone. Moreover, CPTM-P1 showed immunoenhancing properties, effectively augmenting the secretion of nitric oxide and cytokines (TNF-α, IL-1β, and IL-6). Additionally, it significantly enhances the phagocytic capacity of RAW264.7 cells. These findings underscore the potential application of these polysaccharides in functional foods and pharmaceuticals, providing a solid scientific basis for further exploration and utilization of Taxus media polysaccharides.

Angelica gigas polysaccharide induces CR3-mediated macrophage activation and the cytotoxicity of natural killer cells against HCT-116 cells via NF-κB and MAPK signaling pathways

Angelica gigas (A. gigas) is traditional medicinal herb that mainly exists in Korea and northeastern China. There have been relatively few studies conducted thus far on its polysaccharides and their bioactivities. We purified and described a novel water-soluble polysaccharide derived from A. gigas and investigated its immunoenhancing properties. The basic components of crude and purified polysaccharides (F1 and F2) were total sugar (41.07% - 70.55%), protein (1.12–10.33%), sulfate (2.9–5.5%), and uronic acids (0.5–31.05%) in total content. Our results demonstrated that the crude and fractions' molecular weights (Mw) varied from 42.2 to 285.2 × 103 g/mol. As the most effective polysaccharide, F2 significantly stimulated RAW264.7 cells to release nitric oxide (NO) and express several cytokines. Furthermore, F2 increased the expression of tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-ɣ), natural killer cytotoxicity receptors (NKp44), and granzyme-B in NK-92 cells and enhanced the cytotoxicity against HCT-116 cells. In our experiments, we found that F2 stimulated RAW264.7 cells and NK-92 cells via MAPK and NF-κB pathways. The monosaccharide and methylation analysis of the high immunostimulant F2 polysaccharide findings revealed that the polysaccharide was primarily composed of 1 → 4, 1 → 6, 1 → 3, 6, 1 → 3 and 1 → 3, 4, 6 galactopyranose residues, 1 → 3 arabinofuranose residues, 1 → 4 glucopyranose residues. These results demonstrated that the F2 polysaccharide of A. gigas which possesses potential immunostimulatory attributes, could be used to create a novel functional food.

Intranasal vaccination with influenza HA/GO-PEI nanoparticles provides immune protection against homo- and heterologous strains

Intranasal (i.n.) immunization is a promising vaccination route for infectious respiratory diseases such as influenza. Recombinant protein vaccines can overcome the safety concerns and long production phase of virus-based influenza vaccines. However, soluble protein vaccines are poorly immunogenic if administered by an i.n. route. Here, we report that polyethyleneimine-functionalized graphene oxide nanoparticles (GP nanoparticles) showed high antigen-loading capacities and superior immunoenhancing properties. Via a facile electrostatic adsorption approach, influenza hemagglutinin (HA) was incorporated into GP nanoparticles and maintained structural integrity and antigenicity. The resulting GP nanoparticles enhanced antigen internalization and promoted inflammatory cytokine production and JAWS II dendritic cell maturation. Compared with soluble HA, GP nanoparticle formulations induced significantly enhanced and cross-reactive immune responses at both systemic sites and mucosal surfaces in mice after i.n. immunization. In the absence of any additional adjuvant, the GP nanoparticle significantly boosted antigen-specific humoral and cellular immune responses, comparable to the acknowledged potent mucosal immunomodulator CpG. The robust immune responses conferred immune protection against challenges by homologous and heterologous viruses. Additionally, the solid self-adjuvant effect of GP nanoparticles may mask the role of CpG when coincorporated. In the absence of currently approved mucosal adjuvants, GP nanoparticles can be developed into potent i.n. influenza vaccines, providing broad protection. With versatility and flexibility, the GP nanoplatform can be easily adapted for constructing mucosal vaccines for different respiratory pathogens.

Phagocytosis enhancement, endotoxin tolerance, and signal mechanisms of immunologically active glucuronoxylomannan from Auricularia auricula-judae

Glucuronoxylomannan (AAPS) from the edible wood ear mushroom Auricularia auricula-judae has been demonstrated to exhibit immunostimulatory properties through its binding to TLR4. However, the mechanisms of immune modulation by AAPS in mammalian cells remains unclear. In the present study, we demonstrated that AAPS induced immunostimulatory effects were regulated by reactive oxygen species, mitogen-activated protein kinases, protein kinase C-α and NF-κB. AAPS remarkably increased the phagocytosis and bactericidal activity of macrophages. In lipopolysaccharide-activated macrophages, AAPS induced endotoxin tolerance like effect characterized by the downregulation of nitric oxide, interleukin-6 and TNF-α via the downregulation of NF-κB activation. Our findings provide firm scientific evidences for the immunoenhancing properties of wood ear mushroom, and the potential of AAPS to be strong candidates for the development of new carbohydrate-based nutraceutical supplements in the management of immunity related disorders in the future.

1944P Hyperglycemia increased nivolumab-induced cardiotoxicity, enhanced immunoresistance of ERɑ+, PR+, HER2- breast cancer cells modulating growth factors and NLRP3 expression

Type 2 diabetes and metabolic syndrome are negative prognostic factors in breast cancer patients. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, achieving unprecedented efficacy in multiple malignancies. We aimed to study if hyperglycemia could enhance ICI-induced cardiotoxicity in cardiomyocites and immunoresistance in human breast cancer cells. Finally, we evaluated if the treatment with an SGLT-2 inhibitor (empagliflozin) could revert these effects during hyperglycemic condition. Human cardiomyocytes (HL-1 cells) and PD-1+ ERɑ+, PR+, HER2- breast cancer cells (MCF-7 cell line) were exposed to nivolumab (100 nM) at high glucose (25 mM) low glucose (5.5 mM) for 72 h. After the incubation period, we performed the following tests: determination of cell viability, through analysis of mitochondrial dehydrogenase activity; NLRP3, p65/NF-kB and leukotrienes expression through ELISA method. Nivolumab-induced cardiotoxicity was enhanced by 2,7-fold during exposure to 25 mM glucose (High Glucose; HG) compared to 5.5 mM glucose (Low Glucose; LG) in human adult cardiomyocytes. Moreover, IC50 value of nivolumab against MCF7-cells increased significantly under HG vs LG (P<0.01). Moreover, during high glucose condition, cardiomyocytes and human breast cancer cells exposed to nivolumab, increases the expression of NLRP3, p65/NF-kB, leukotrienes and cytokines. Notably, hyperglycemia increases significantly the intracellular calcium (iCa2+) content in cardiomyocytes during incubation with nivolumab, probably increasing the metabolic susceptibility to damages induced by ICI. Shifting from HG to LG, as well as the administration of 50 nM empagliflozin reduced the magnitude of cardiotoxic effects, indicating cardioprotective and immuno-enhancing properties. To our knowledge these results are the first evidence that hyperglycemia exacerbates ICI-induced cardiotoxicity and immunoresistace and set the stage to preclinical and clinical trials aimed to decrease glucose through dietary or lifestyle changes or through new hypoglycemic drugs (gliflozins).

Improved proliferation of antigen-specific cytolytic T lymphocytes using a multimodal nanovaccine.

The present study investigated the immunoenhancing property of our newly designed nanovaccine, that is, its ability to induce antigen-specific immunity. This study also evaluated the synergistic effect of a novel compound PBS-44, an α-galactosylceramide analog, in boosting the immune response induced by our nanovaccine. The nanovaccine was prepared by encapsulating ovalbumin (ova) and an adjuvant within the poly(lactic-co-glycolic acid) nanoparticles. Quantitative analysis of our study data showed that the encapsulated vaccine was physically and biologically stable; the core content of our nanovaccine was found to be released steadily and slowly, and nearly 90% of the core content was slowly released over the course of 25 days. The in vivo immunization studies exhibited that the nanovaccine induced stronger and longer immune responses compared to its soluble counterpart. Similarly, intranasal inhalation of the nanovaccine induced more robust antigen-specific CD8+ T cell response than intraperitoneal injection of nanovaccine.

A polysaccharide fraction from Achillea millefolium increases cytokine secretion and reduces activation of Akt, ERK and NF-κB in THP-1 monocytes

Achillea millefolium has been used in traditional medicine for a number of ailments, including skin inflammation and wounds. A polysaccharide fraction (Am-25-d) isolated from aqueous extract from A. millefolium had an average molecular weight of 270kDa and a monosaccharide composition of GalA, Gal, Ara, Xyl, Rha in molar ratio of 28:26:23:9:7. THP-1 cells primed with IFN-γ and stimulated with LPS in the presence of Am-25-d secreted more IL-1β, IL-8, IL-10, IL-12p40, IL-23 and TNF-α than THP-1 cells stimulated in the absence of Am-25-d. However, when added to unstimulated cells Am-25-d did not increase secretion of the cytokines examined. Stimulating THP-1 monocytes in the presence of Am-25-d led to decreased nuclear concentrations of NF-κB and phosphorylation of ERK1/2 and Akt kinases compared with that when the cells were stimulated without Am-25-d. These findings indicate that Am-25-d isolated from A. millefolium has immunoenhancing properties that may be mediated via the Akt pathway.

Mushroom polysaccharides as potential prebiotics with their antitumor and immunomodulating properties: A review

Mushrooms seem to be a potential source for prebiotics as they contain different polysaccharides such as chitin, hemicellulose, α- and β-glucans, mannans, xylans and galactans. Among mushroom polysaccharides, β-(1→3)-D-glucans, and their peptide/protein derivates (polysaccharide-peptide/protein complexes), proteoglycans are essential prebiotics and found to play vital role in immunomodulating and antitumor activities. These prebiotic compounds display immunomodulating and antitumor activity similar to those effected by immune effector cells such as lymphocytes, macrophages, hematopoietic stem cells, T cells, dendritic cells (DCs) and natural killer (NK) cells that play essential roles in innate and adaptive immunity, resulting in production of biologic response modifiers. Several glucans and heteroglycans were found with their significant immunoenhancing properties which could stimulate the macrophages, splenocytes and thymocytes. Thus this review aims to summarize and explore the potential of mushroom polysaccharides as prebiotics with their antitumor and immunomodulating properties for the development of nutraceutical foods and drugs.

Immunoenhancing properties of the anti-tumor effects of adoptively transferred T cells with chemotherapeutic cyclophosphamide by co-administration of bone marrow cells

In this study we aimed to determine the anti-tumor efficacy of co-treatment of adoptively transferred T cells with bone marrow either harvested from naïve mice or G-CSF activated after treatment with the anti-cancer drug cyclophosphamide (CTX) as a source enriched in stem cells. CTX-treated Swiss Albino (CD-1) mice were injected with 2×105 Ehrlich ascetic carcinoma (EAC) cell line and then adoptively transferred with in vitro co-activated T cells with or without bone marrow one day post CTX treatment. All mice were vaccinated with tumor lysate and Hiltonol®. The results showed that co-transfer of activated T cells with bone marrow provided the highest antitumor effect and induced marked increase in numbers of splenocytes, leucocytes and bone marrow cells. Interestingly, T cells derived from EAC tumor-bearing host induced higher effects than those from normal mice. In sum, our data suggest that combination of CTX and activated transferred T cells with bone marrow induces proliferation and expansion of immune cells, which are functional and can be exploited in vivo to foster more effective antitumor adoptive immunotherapy strategies.

Synthesis of conformationally constrained γ-d-glutamyl-meso-diaminopimelic acid derivatives as ligands of nucleotide-binding oligomerization domain protein 1 (Nod1)

Nod1, an important member of the pattern recognition receptor family, remains a virtually unexploited target. Harnessing its innate immune stimulatory properties still remains an unfulfilled goal of medicinal chemistry. Nucleotide-binding oligomerization domain protein 1 (Nod1) agonists have been shown to boost the inflammatory responses against pathogenic microbes and could thus constitute a new class of broad spectrum antimicrobial agents. To gain additional insight into the structure/activity relationships of Nod1 agonistic compounds, a series of novel, conformationally constrained γ-d-glutamyl-meso-diaminopimelic acid (iE-DAP) analogs have been designed and synthesized. Ramos-Blue cells expressing Nod1 were used to screen and validate our compounds for their Nod1-agonist activity. Their immunomodulatory properties were subsequently determined in vitro, by evaluating their capacity to induce pro-inflammatory cytokine and chemokine production from human peripheral blood mononuclear cells (PBMC), by themselves and in synergy with lipopolysaccharide (LPS), a Toll-like receptor 4 (TLR4) ligand. The synthesized iE-DAP analogs were shown to possess immuno-enhancing properties as a result of their potent and specific Nod1-agonistic effect. The activity of the compound exhibiting the greatest capacity to induce pro-inflammatory cytokine release from PBMC surpassed that of lauroyl-γ-d-glutamyl-meso-diaminopimelic acid (C12-iE-DAP).

Effects of &lt;i&gt;Gan Lian Yuping Feng&lt;/i&gt; powder on the antibody titers to infectious laryngotracheitis vaccine and some nonspecific immune indexes in chickens

The study was conducted in order to investigate the immuno-enhancing property of the Chinese herbal formula, Gan lian Yu ping feng powder. Three hundred and thirty six 45-day-old chicks were randomly divided into eight groups. The chicks in groups A, B, C were orally given 0.25 g/mL (low-), 0.5 g/mL (middle-) and 1.0 g/mL (high) dose of Gan lian Yu ping feng powder in the drinking water respectively for 3 days consecutively. They were then immunised with infectious laryngotracheitis vaccine (ILTV) on the 4th day. Groups D, E, F were given 0.25 g/mL, 0.5 g/mL and 1.0 g/mL dose of Gan lian Yu ping feng powder respectively after the immunisation for three days consecutively. Group G was Wen du qing (a government approved herbal product for ILT) control group, and group H was blank control group. At 52, 59, 73, 87 days of age, 8 chicks of each group were selected randomly for blood sampling to determine the levels of IFN-γ, IL-4 and the antibody of ILT. Then the chickens were sacrificed, with the thymus, spleen and Bursa of Fabricius being weighed for the calculation of immune organ indexes. The results showed that high and middle dosages of Gan lian Yu ping feng powder given at the day before immunisation and 3 days after immunisation elevated not only the contents of IFN-γ, the antibody titers of ILT (P<0.01) and the immune organ indexes (P<0.05) significantly, but also reduced the contents of IL-4. There was a significantly different degree of enhancement in the content of IFN-γ, the antibody of ILT (P<0.01) and the immune organ index (P<0.05). The results indicate that Gan lian Yu ping feng powder effectively improves the immunity in chickens.

Glucan from hot aqueous extract of an ectomycorrhizal edible mushroom, Russula albonigra (Krombh.) Fr.: structural characterization and study of immunoenhancing properties

A water soluble glucan (PS-I) was isolated from the hot aqueous extract of the fruit bodies of an ectomycorrhizal edible mushroom, Russula albonigra (Krombh.) Fr. The total hydrolysis, methylation analysis, periodate oxidation, and NMR (1H, 13C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC) studies revealed the presence of the following repeating unit in the polysaccharide: [Display omitted] This glucan showed excellent activation of macrophages as well as splenocytes and thymocytes in vitro.

Effects of Chinese herbal recipes on immunity in immunosuppressive mice.

The Chinese herbal formula consisting of Astragalus membranaceus, Epimedium brevicornum, Paeoniae Alba Radix and Radix Ophiopogonis in proper proportions were adopted in order to investigate the immunoenhancing properties of the herbal formula. Fifty ICR mice were randomly divided into 5 groups (NS- NS+Hy-L+Hy-M+Hy-H+Hy ). The mice in hydrocortisone (Hy) groups were injected with hydrocortisone i.p. to induce the immunosuppressive condition. The mice in group NS were administered with normal saline as controls. The mice in groups NS+Hy-L+Hy-M+Hy-H+Hy were administered with normal saline, low, moderate and high dose of the herbal prescription respectively by gavage for 6 days. The level of serum hemolysin, the function of antibody function cell-AFC-and CD4⁺/CD8⁺ T cell ratio were measured at the end of experiments. The results showed that the level of serum hemolysin, the function of AFC and CD4⁺/CD8⁺ T cell ratio in L+Hy-M+Hy-H+Hy groups increased significantly compared with those in NS or NS+Hy groups. These results indicate that Chinese herbal medicine prescription can enhance humoral immunity and cellular immune function of the immunosuppressive mouse.

Immunomodulatory Properties of Novel Nucleotide Oligomerization Domain 2 (Nod2) Agonistic Desmuramyldipeptides

There is a pressing need for the development of novel adjuvants for human use. The minimal bioactive structure of bacterial peptidoglycan (PGN), muramyldipeptide (MDP), and its derivative murabutide (MB) have long been known for their adjuvant activities. For this reason, a series of novel desmuramyldipeptides have been designed and synthesized as part of our search for therapeutically useful MDP analogues. Since nucleotide oligomerization domain 2 (Nod2) is a putative receptor for MDP, we used engineered HEK293 cells overexpressing Nod2 to screen and validate our compounds for their Nod2-agonist activity. Their immunomodulatory properties were subsequently assessed in vitro by evaluating their effect on proinflammatory cytokine production of phorbol 12-myristate 13-acetate (PMA)/ionomycin-stimulated human peripheral blood mononuclear cells (PBMCs). Herein, we present novel desmuramyldipeptides, the most active of them possessing immunoenhancing properties as a result of their potent Nod2-agonistic effect.

Structural characterization and study of immunoenhancing properties of a glucan isolated from a hybrid mushroom of Pleurotus florida and Lentinula edodes

A water soluble glucan isolated from hot aqueous extract of fruit bodies of an edible hybrid mushroom Pfle1r of Pleurotus florida and Lentinula edodes showed macrophages, splenocytes, and thymocytes activation. The glucan consists of terminal, (1→3,6)-linked, and (1→6)-linked β-d-glucopyranosyl moieties in a molar ratio of nearly 1:1:3. On the basis of acid hydrolysis, methylation, periodate oxidation study, and NMR studies (1H, 13C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC), the structure of the repeating unit of the glucan was established as: [Display omitted]

Heteroglycan from an alkaline extract of a somatic hybrid mushroom (PfloVv1aFB) of Pleurotus florida and Volvariella volvacea: structural characterization and study of immunoenhancing properties

A water soluble heteroglycan, isolated from the alkaline extract of the fruit bodies of the somatic hybrid mushroom (PfloVv1aFB), raised through protoplast fusion between the strains of Pleorutus florida and Volverilla volvacea, was found to consist of (1→3)-, (1→6)-, (1→3,4)-linked, and terminal β-d-Glcp along with (1→2,6)-α-d-Galp and terminal α-d-Manp in a relative proportion of approximately 1:1:1:1:1:1. This polysaccharide exhibited strong immunostimulating activity of macrophages as well as splenocytes and thymocytes. Structural investigation was carried out using sugar analysis, methylation analysis; periodate oxidation study, and NMR experiments (1H, 13C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of the above mentioned experiments, the structure of the repeating unit of the polysaccharide was established as: [Display omitted]

Structural characterization and study of immunoenhancing properties of heteroglycan isolated from a somatic hybrid mushroom (PfloVv1aFB) of Pleurotus florida and Volvariella volvacea

A water soluble polysaccharide isolated from the hot aqueous extract of the fruit bodies of the somatic hybrid mushroom (PfloVv1aFB), raised through protoplast fusion between the strains of Pleurotus florida and Volvariella volvacea was found to consist of d-glucose, d-galactose, and d-mannose in a molar ratio of nearly 4:1:1 and showed macrophage, splenocyte, and thymocyte activation. On the basis of sugar analysis, methylation analysis, periodate oxidation, and NMR studies (1H, 13C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC and HMBC), the structure of the repeating unit of the polysaccharide was established as:▪