Group Of Polysaccharides Research Articles

A polysaccharide from Periplaneta americana promotes macrophage M2 polarization, exhibiting anti-inflammatory and wound-healing activities

A miscellaneous polysaccharide, PAP55–3-1, with a molecular weight of 23.03 kDa, was isolated from Periplaneta americana through extraction with dilute alkali solution, ethanol precipitation, and column chromatography purification. Structural analysis shows that PAP55–3-1 is mainly composed of five monosaccharides: galactosamine hydrochloride, glucosamine hydrochloride, galactose, glucose and mannose. Its main glycosidic bonds are: Manp-(1→, Galp-(1→, →3)-Galp-(1→, →3,6)-Manp-(1→, →2,6)-Manp-(1→, →6)-Manp-(1→, →4)-Galp-(1→, →6-Glcp-(1→, →6)-Galp-(1→, →2)-Manp-(1 →, →3,4)-Glcp-(1→, →3,6)-Galp-(1→. In vitro experiments demonstrated that PAP55–3-1 can effectively inhibit reactive oxygen species (ROS) and O2− production following H2O2−induction. After H2O2−induction, HIF-1α (hypoxia-inducible factor) was translocated in mitochondria PAP55–3-1 increased localization of HIF-1α was located on mitochondria to maintain the stability of mitochondrial function stability, thereby effectively inhibiting H2O2-induced mitochondrial oxidative damage. Additionally, PAP55–3-1 inhibited the M1 polarization of macrophages stimulated by H2O2 and promoted the phenotype polarization of macrophages from M1 to M2, displaying anti-inflammatory and pro-repair properties. In vivo experimental results indicated that PAP55–3-1 promoted wound healing in mice. Immunohistochemical experiments revealed a reduction in CD68 expression and increase in CD206 expression in both positive and the high-dose polysaccharide group control group. This further demonstrated that PAP55–3-1 promotes the phenotype polarization of macrophages from M1 to M2, exerting anti-inflammatory and wound-healing activities.

Recovery of Selenium-Enriched Polysaccharides from Cardamine violifolia Residues: Comparison on Structure and Antioxidant Activity by Different Extraction Methods.

The residues from selenium-enriched Cardamine violifolia after the extraction of protein were still rich in polysaccharides. Thus, the recovery of selenium polysaccharides (SePSs) was compared using hot water extraction and ultrasonic-assisted extraction techniques. The yield, extraction rate, purity, specific energy consumption, and content of total and organic selenium from different SePS extracts were determined. The results indicated that at conditions of 250 W (ultrasonic power), 30 °C, and a liquid-to-material ratio of 30:1 extracted for 60 min, the yield of SePSs was 3.97 ± 0.07%, the extraction rate was 22.76 ± 0.40%, and the purity was 65.56 ± 0.35%, while the total and organic selenium content was 749.16 ± 6.91 mg/kg and 628.37 ± 5.93 mg/kg, respectively. Compared to traditional hot water extraction, ultrasonic-assisted extraction significantly improves efficiency, reduces energy use, and boosts both total and organic selenium content in the extract. Measurements of particle size, molecular weight, and monosaccharide composition, along with infrared and ultraviolet spectroscopy, revealed that ultrasonic-assisted extraction breaks down long-chain structures, decreases particle size, and changes monosaccharide composition in SePSs, leading to lower molecular weight and reduced dispersity. The unique structure of SePSs, which integrates selenium with polysaccharide groups, results in markedly improved antioxidant activity and reducing power, even at low concentrations, due to the synergistic effects of selenium and polysaccharides. This study establishes a basis for using SePSs in functional foods.

Study of the Effects of Alfalfa Bioactive Substances and Polysaccharides on the Lactation Performance and Immune Function of Dairy Cows

Background: The aim of this study was to investigate the effects of alfalfa polysaccharides on the lactation performance and immune function of dairy cows. Methods: A total of 84 healthy Holstein cows were selected and randomly divided into 7 groups, including the control Group A0, the alfalfa polysaccharide groups (AP1, AP2, AP3) and the alfalfa extract groups (AE1, AE2, AE3). Each group had three replicates and each replicate had four cows. The daily rations of the dairy cows in the AP group and the AE group were supplemented with alfalfa polysaccharide powder and alfalfa extract at concentrations of 1, 2 and 3 kg/t, those in the A0 group served as a control. Result: (1) the milk production of dairy cows in the AE groups was extremely significantly greater (p less than 0.01) than that in A0 group and AP groups. The milk protein content of cows in the AP2 and AE2 groups was significantly greater (P less than 0.05) than that in the A0 group (2) The interleukin-2 (IL-2) levels in the serum of cows in the AP2, AP3, AE2 and AE3 groups were greater than those in the A0 and AP1 groups and the IgM antibody levels in the AP group and the AE group were extremely significantly greater than those in the A0 and AP1 groups (P less than 0.01). The IgA antibody level in the serum of dairy cows in the AP2, AP3, AE2 and AE3 groups was significantly (P less than 0.01) greater than that in the A0, AP1 and AE1 groups. In summary, the alfalfa extract improved both the lactation performance and immunity of dairy cows, indicating comprehensive effects. Alfalfa polysaccharides at a concentration of 2 kg/t improved the immunity of dairy cows.

Interaction of biochar with extracellular polymers of resistant bacteria restrains Pb(II) adsorption onto their composite: Macro and micro scale investigations

Pb(II) sequestration in extracellular polymers-biochar composites (EPS-BC) was explored using macroscopic models and microscopic technology. The results showed that the actual adsorption capacity of EPS-BC was 52.2% lower than the calculated capacity based on adsorption onto pure components due to the interaction of polysaccharide and amide group in extracellular polymers with biochar, which masked the reactive sites related to Pb(II) in EPS-BC. The bond of Pb–O (40.8%) and Pb–OOC (31.5%) mainly contributed to Pb(II) speciation on the EPS-BC surfaces. Furthermore, each Pb atom coordinated with 6O atoms in the first shell and with 0.5C atoms in the second shell, indicating that the carboxyl group in composite was complexed with Pb(II) as a monodentate inner-sphere structure. The findings provide an in-depth understanding of the adsorption mechanism of heavy metals by extracellular polymers coupled with biochar at molecular scale, guiding bioremediation with respect to heavy metal contamination.

Nutrition and health effects of pectin: A systematic scoping review of human intervention studies.

Pectin is composed of a group of complex polysaccharides that are naturally found in various plants and are associated with a range of beneficial health effects. Health outcomes from dietary pectin can vary depending on botanical origin, dietary dose and structure of pectin. The objective of this scoping review is to build a comprehensive overview of the current evidence available on intervention studies conducted in humans and to better understand the possible knowledge gaps in terms of structure-function relationships across the different health-related effects. PubMed and Embase databases were searched using PRISMA-ScR guidelines, yielding 141 references (from the initial 3704), representing 134 intervention studies performed between 1961 and 2022 that met inclusion criteria. Studies were divided into six categories, which included gut health, glycaemic response and appetite, fat metabolism, bioavailability of micronutrients, immune response and other topics. Review of these human intervention studies identified a variety of cohort characteristics and populations (life stage, health status, country), sources/types of pectin (i.e. citrus, sugarbeet, apple, other and non-defined), intervention timeframes (from one single intake to 168 d) and doses (0.1-50 g/d) that were tested for health outcomes in people. Gut health, post-prandial glucose regulation and maintenance of blood cholesterol represented the largest categories of studied outcomes. Further research to strengthen the structure-function relationships for pectin with health properties and associated outcomes is warranted and will benefit from a more precise description of physico-chemical characteristics and molecular compositions, such as degree of esterification, weight, degree of branching, viscosity, gel formation and solubility.

Research progress in the synthesis of 3'- and 6'-sialactose by Escherichia coli

Human milk oligosaccharides (HMOs) are a structurally complex group of unbound polysaccharides, representing the third-largest solid component in breast milk. They play a crucial role in the intestinal health and immune system development of infants. Sialylated HMOs, including 3'-sialactose (3'-SL) and 6'-sialactose (6'-SL), are major components of HMOs, playing significant roles in immune regulation, anti-inflammatory processes, and promotion of probiotic growth. Currently, the cost-effective production of high-value sialactose by microbial fermentation with readily available raw materials has become a research hotspot due to the high nutritional value and potential applications of sialylated HMOs in infant food. This paper summarizes the functions and biosynthesis of 3'-SL and 6'-SL. Furthermore, it reviews the research progress in the synthesis of sialactose by Escherichia coli, offering valuable insights for future industrial production.

Exopolysaccharides from Weissella cibaria isolated from oats: isolation, characterisation and its application in improving the texture of set‐type yogurt

SummaryIn this study, a lactic acid bacteria strain isolated from oats was used as a producer to obtain exopolysaccharide (EPS) using MRS agar plates. The findings indicated that the bacterial strain identified as Weissella cibaria (accession number: PP515290) was shown to have good probiotic activity, adapt better to alkaline than acidic conditions, and efficiently produce EPS at concentrations of up to 7.93 g L−1. SEM images showed a smooth surface and compact particle whereas FTIR confirmed the basic functional groups of polysaccharides in the sample. Meanwhile, XRD analysis demonstrated a non‐crystalline amorphous structure and thermal analysis indicated two‐phase thermal decomposition with maximum rate at 210 °C. Subsequently, EPS from W. cibaria was applied as stabiliser in set‐type yogurt (ex situ) in comparison with yogurt using mixed culture with W. cibaria (in situ) and traditional starter culture (control). The results showed that the addition of 2% EPS significantly improved syneresis (14.31%) compared to co‐culture (27.50%) and control (29.80%) as well as increased hardness of yogurt during 2‐week refrigeration.

Low concentrations of methyl jasmonate promote plant growth and mitigate Cd toxicity in Cosmos bipinnatus

Cadmium (Cd) is a biologically non-essential heavy metal, a major soil pollutant, and extremely harmful to plants. The phytohormone methyl jasmonate (MeJA) plays an important role in plant heavy-metal resistance. However, the understanding of the effects of MeJA supply level on alleviating Cd toxicity in plants is limited. Here, we investigated how MeJA regulated the development of physiological processes and cell wall modification in Cosmos bipinnatus. We found that low concentrations of MeJA increased the dry weight of seedlings under 120 µM Cd stress by reducing the transport of Cd from roots to shoots. Moreover, a threshold concentration of exogenous MeJA increased the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in plant roots, the concentration of Cd in the root cell wall, and the contents of pectin and hemicellulose 1 polysaccharides, through converting Cd into pectin-bound forms. These results suggested that MeJA mitigated Cd toxicity by modulating root cell wall polysaccharide and functional group composition, especially through pectin polysaccharides binding to Cd, with effects on Cd transport capacity, specific chemical forms of Cd, and homeostatic antioxidant systems in C. bipinnatus.

Cross-linking impacts the physical properties of mycelium leather alternatives by targeting hydroxyl groups of polysaccharides and amino groups of proteins

Cross-linking, also called tanning, improves mechanical properties of leather and also increases its enzymatic and thermal stability. As a final product, leather has an ultimate tensile strength (σ) of 8–25 MPa and an elongation at break (ε) of >30 %. Mycelium-based materials are a sustainable alternative to leather. Here, the effect of cross-linkers was assessed on mechanical properties of Schizophyllum commune mycelium sheets. To this end, glutaraldehyde and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC) were used as well as extracts of Ligustrum vulgare leaves, and bark of Acacia mearnsii and Caesalpinia spinosa. Untanned sheets had a σ of 7.8 MPa and an ε of 15.2 %, while the best overall combination of strength and elasticity was obtained with 0.1 % glutaraldehyde with a σ of 11.1 MPa and an ε of 14.6 %. Cross-linking also increased enzymatic stability and reduced mycelial water absorption but did not result in increased thermal stability. Fourier transform infrared spectroscopy (FTIR), 1D nuclear magnetic resonance spectroscopy (NMR), and amino acid analysis showed that glutaraldehyde bound both protein amino groups and polysaccharide hydroxyl groups by forming Schiff bases and acetals, respectively. Together, synthetic and vegetable cross-linkers can be used to obtain mycelium materials with leather-like tensile strength.

Effects of Different Drying Methods on the Structural Characteristics and Multiple Bioactivities of Rosa roxburghii Tratt Fruit Polysaccharides.

Drying conditions significantly impact the compositions and microstructures of polysaccharides, leading to various effects on their chemical characteristics and bioactivities. The objective of this study was to investigate how different industrial drying techniques, i.e., hot air drying, infrared drying, microwave vacuum drying, and freeze drying, affect the structural properties and biological activities of polysaccharides extracted from Rosa roxburghii Tratt fruit (RRTP). Results revealed that these drying methods significantly altered the extraction yield, molecular weights, monosaccharide ratios, contents of uronic acid and total sugars, gelling properties, particle sizes, thermal stability, and microstructures of RRTPs. However, the monosaccharide composition and functional groups of polysaccharides remained consistent across the different drying techniques. Biological activity assays demonstrated that RRTPs, particularly those processed through microwave vacuum drying (MVD-RRTP), exhibited excellent anti-linoleic acid oxidation, robust anti-glycosylation effects, and significant α-glucosidase inhibition in vitro. The outcomes of this research demonstrate that microwave vacuum drying serves as an effective pre-extraction drying method for RRTPs, enhancing their biological activities. This technique is particularly advantageous for preparing RRTPs intended for use in functional foods and pharmaceuticals, optimizing their health-promoting properties for industrial applications.

Evaluation of candidate International Standards for meningococcal capsular polysaccharide groups W and Y

Two candidate International Standards for meningococcal capsular group W and Y (MenW and MenY, respectively) polysaccharides were assessed for their suitability as quantitative standards in various physicochemical assays. The study was designed to evaluate the intended purpose of these standards, namely, to standardize the quantification of the respective polysaccharide content in meningococcal polysaccharide and conjugate vaccines and their intermediate components. Twelve laboratories from eleven different countries participated in the collaborative study of candidate preparations for International Standards for MenW and MenY polysaccharide (coded 16/152 and 16/206, respectively). Unitage was assigned using the Resorcinol assay. Our proposals, on the basis of data from the Resorcinol assay were: 1) candidate standard for MenW polysaccharide (16/152) to be assigned a content of 1.015 ± 0.071 mg MenW polysaccharide per ampoule (expanded uncertainty with coverage factor k = 2.13, corresponding to a 95 % level of confidence) and 2) candidate standard for MenY polysaccharide (16/206) be assigned a content of 0.958 ± 0.076 mg MenY polysaccharide per ampoule (expanded uncertainty with coverage factor k = 2.26, corresponding to a 95 % level of confidence). The amount of polysaccharide per ampoule remained consistent under all stability conditions over a 36-month period.

Structural characterization and immunomodulating assessment of ultra-purified water extracted fucoidans from Saccharina latissima, Alaria esculenta and Laminaria hyperborea

Fucoidans, a group of high molecular weight polysaccharides derived mainly from brown algae, are characterized by their high fucose content, degree of sulfation (DS), and intra- and interspecific structural variation. Fucoidans are increasingly recognized due to various reported bioactivities, potentially beneficial for human health. To unlock their potential use within biomedical applications, a better understanding of their structure-functional relationship is needed. To achieve this, systematic bioactivity studies based on well-defined, pure fucoidans, and the establishment of standardized, satisfactory purification protocols are required. We performed a comprehensive compositional and structural characterization of crude and ultra-purified fucoidans from three kelps: Saccharina latissima (SL), Alaria esculenta (AE) and Laminaria hyperborea (LH). Further, the complement-inhibiting activity of the purified fucoidans was assessed in a human whole blood model. The purification process led to fucoidans with higher DS and fucose and lower concentrations of other monosaccharides. Fucoidans from SL and LH resembles homofucans, while AE is a heterofucan rich in galactose with comparably lower DS. Fucoidans from SL and LH showed complement-inhibiting activity in blood and blood plasma, while no inhibition was observed for AE under the same conditions. The results emphasize the importance of high DS and possibly fucose content for fucoidans' bioactive properties.

Deciphering the genetic architecture of β-glucan content in oats (Avena sativa L.) through QTL mapping

Oat is a cereal grain grown for human and animal nutrition. It is known for its high dietary fibre content, phytochemicals, and nutritional value. The primary component of oat fibre is β-glucan, a group of polysaccharides comprising mixed-linkage (1,3) (1,4)-D-glucose units. The β-glucan concentrations of oat cultivars usually range from 3 to 6% and are considered a polygenic trait controlled by multiple genes with additive effects. The primary goal of this study was to identify quantitative trait loci (QTLs) for β-glucan content. Two contrasting parents for β-glucan content, OL10 (5.8%) and OL11 (0.8%), were selected from 91 germplasm lines, and an F2:4 mapping population was generated for QTL mapping. Five genotypes with the highest levels of β-glucan content were observed. The QTLs affecting β-glucan content were identified using QTL cartographer, employing single marker analysis (SMA) and composite interval mapping (CIM). Two putative QTL regions were identified, one on linkage group (LG) 1 and the other on LG 4, with LOD (logarithm of the odds) scores of 3.7 and 4.3, respectively, explaining 31 and 33% of the phenotypic variation. The information generated is important in identifying the genomic regions responsible for β-glucan content in oats.

Modeling 1-Cyano-4-Dimethylaminopyridine Tetrafluoroborate (CDAP) Chemistry to Design Glycoconjugate Vaccines with Desired Structural and Immunological Characteristics.

Glycoconjugation is a well-established technology for vaccine development: linkage of the polysaccharide (PS) antigen to an appropriate carrier protein overcomes the limitations of PS T-independent antigens, making them effective in infants and providing immunological memory. Glycoconjugate vaccines have been successful in reducing the burden of different diseases globally. However, many pathogens still require a vaccine, and many of them display a variety of glycans on their surface that have been proposed as key antigens for the development of high-valency glycoconjugate vaccines. CDAP chemistry represents a generic conjugation strategy that is easily applied to PS with different structures. This chemistry utilizes common groups to a large range of PS and proteins, e.g., hydroxyl groups on the PS and amino groups on the protein. Here, new fast analytical tools to study CDAP reaction have been developed, and reaction conditions for PS activation and conjugation have been extensively investigated. Mathematical models have been built to identify reaction conditions to generate conjugates with wanted characteristics and successfully applied to a large number of bacterial PSs from different pathogens, e.g., Klebsiella pneumoniae, Salmonella Paratyphi A, Salmonella Enteritidis, Salmonella Typhimurium, Shighella sonnei and Shigella flexneri. Furthermore, using Salmonella Paratyphi A O-antigen and CRM197 as models, a design of experiment approach has been used to study the impact of conjugation conditions and conjugate features on immunogenicity in rabbits. The approach used can be rapidly extended to other PSs and accelerate the development of high-valency glycoconjugate vaccines.

Land Degradation Affects Soil Microbial Properties, Organic Matter Composition, and Maize Yield

Land degradation severely affects soil functions, thereby weakening crop productivity. However, the quantitative effects of the soil organic matter (SOM) composition and soil microbial properties on maize yield remain unclear under different levels of land degradation. Here, a gradient of land degradation was selected for sampling in the Horqin Sandy Land in northeast China. The results show that the relative abundances of aliphatic and aromatic groups decreased by 21.51% and 86.01% with increasing land degradation, respectively, and the considerable increase in polysaccharide groups led to a decrease in stability and resistance to SOM decomposition. Microbial properties, such as microbial biomass carbon, basic respiration, qCO2, and enzyme activities, decreased as a result of land degradation. The phospholipid fatty acid content and the ratio between bacteria and fungi markedly decreased with an increasing level of land degradation, and the ratio of G+ to G− markedly increased. Correlation analysis confirmed that the microbial properties were significantly related to the SOM composition, and the random forest model indicated that fungi were key factors affecting maize yield (7.15%, p < 0.05). Moreover, the results of the structure equation modelling revealed that land degradation reduced the soil physiochemical properties, resulting in a decrease in microorganisms, causing variations in the SOM composition and directly leading to a decrease in crop yield. The effect of microorganisms (β = 0.84 ***) on maize yield was greater than that of the SOM composition (β = 0.53 **). Our investigation can provide a theoretical basis for the conservation of the cropland in Horqin Sandy Land.

Preliminary Screening on Antibacterial Crude Secondary Metabolites Extracted from Bacterial Symbionts and Identification of Functional Bioactive Compounds by FTIR, HPLC and Gas Chromatography-Mass Spectrometry.

Secondary metabolites, bioactive compounds produced by living organisms, can unveil symbiotic relationships in nature. In this study, soilborne entomopathogenic nematodes associated with symbiotic bacteria (Xenorhabdus stockiae and Photorhabdus luminescens) were extracted from solvent supernatant containing secondary metabolites, demonstrating significant inhibitory effects against E. coli, S. aureus, B. subtilus, P. mirabilis, E. faecalis, and P. stutzeri. The characterization of these secondary metabolites by Fourier transforms infrared spectroscopy revealed amine groups of proteins, hydroxyl and carboxyl groups of polyphenols, hydroxyl groups of polysaccharides, and carboxyl groups of organic acids. Furthermore, the obtained crude extracts were analyzed by high-performance liquid chromatography for the basic identification of potential bioactive peptides. Gas chromatography-mass spectrometry analysis of ethyl acetate extracts from Xenorhabdus stockiae identified major compounds including nonanoic acid derivatives, proline, paromycin, octodecanal derivatives, trioxa-5-aza-1-silabicyclo, 4-octadecenal, methyl ester, oleic acid, and 1,2-benzenedicarboxylicacid. Additional extraction from Photorhabdus luminescens yielded functional compounds such as indole-3-acetic acid, phthalic acid, 1-tetradecanol, nemorosonol, 1-eicosanol, and unsaturated fatty acids. These findings support the potential development of novel natural antimicrobial agents for future pathogen suppression.

Polysaccharide of sunflower (Helianthus annuus L.) stalk pith inhibits cancer proliferation and metastases via TNF-α pathway

The decoctions of sunflower (Helianthus annuus L. HAL) stalk pith have been used to treat advanced cancer, and polysaccharide of sunflower stalk pith (HSPP) was key ingredient of the decoctions. To forage specially structured HSPP with anti-tumor effects and to uncover its mechanisms of anticancer activity, syngeneic mouse model of lung carcinoma metastasis was established and the HSPP was found to contain long-chain fatty acid. Encouragingly, the mean survival of the polysaccharide group (47.3 ± 12.8 d) and its sub-fractions group HSPP-4 (50.7 ± 13.0 d) was significantly increased compared with control group (38.7 ± 12.7 d) or positive control group (41.8 ± 13.4 d), (n = 20, P < 0.01 vs. the control group or positive control group). Furthermore, the HSPP exerted inhibitory effects on the tumor cells' metastasis. Eventually, it is postulated that the polysaccharide could inhibit tumor proliferation and metastasis by reduction of TNF-α from the macrophage.

Modulation of cyclophosphamide-induced immunosuppression and intestinal flora in broiler by deep eutectic solvent extracted polysaccharides of Acanthopanax senticosus.

The aim of this experiment was to investigate the modulation effect of Acanthopanax senticosus polysaccharide (ASPS-PD) extracted with deep eutectic solvent on cyclophosphamide-induced immunosuppression in broilers and its modulation of the gut microbiota of broilers. The 108 one-day-old broilers were divided into six groups, including the control group, the Cyclophosphamide (CY) model group, the ASPS-PD control group, the ASPA-PD high and low dose groups and the Astragalus polysaccharide group. Body weight, feed intake, feed conversion ratio, and immune organ index of broilers at 7, 14, and 21 days were determined; IL-2, IFN-γ, and lgG1 levels were determined by enzyme-linked immunosorbent assay (ELISA); Broiler caeca feces were analyzed by amplification and 16S rRNA sequencing. The results showed that ASPS-PD can restore growth performance, increase immune organ index and improve serum cytokine levels of IL-2 and IFN-γ and immunoglobulin lgG1 levels in CY-treated broilers. The analysis of cecum flora showed that ASPS-PD can promote the proliferation of beneficial bacteria and reduce the number of harmful bacteria, regulating intestinal flora. Therefore, ASPA-PD may be a potential novel immunomodulator to ameliorate CY-induced immunosuppression and intestinal flora dysregulation in broiler.

Using Surface Immunogenic Protein as a Carrier Protein to Elicit Protective Antibody to Multiple Serotypes for Candidate Group B Streptococcal Glycan Conjugate Vaccines.

Group B Streptococcus (GBS) is a life-threatening opportunistic pathogen, particularly in pregnant women, infants, and the elderly. Currently, maternal vaccination is considered the most viable long-term option for preventing GBS mother-to-infant infection, and two polysaccharide conjugate vaccines utilizing CRM197 as a carrier protein have undergone clinical phase II trials. Surface immunogenic protein (Sip), present in all identified serotypes of GBS strains so far, is a protective surface protein of GBS. In this study, the type Ia capsular polysaccharide (CPS) of GBS was utilized as a model to develop candidate antigens for a polysaccharide conjugate vaccine by coupling it with the Sip of GBS and the traditional carrier protein CRM197. Serum analysis from immunized New Zealand rabbits and CD1 mice revealed that there was no significant difference in antibody titers between the Ia-Sip group and Ia-CRM197 group; however, both were significantly higher than those observed in the Ia polysaccharide group. Opsonophagocytosis and passive immune protection results using rabbit serum indicated no significant difference between the Ia-Sip and Ia-CRM197 groups, both outperforming the Ia polysaccharide group. Furthermore, serum from the Ia-Sip group had a cross-protective effect on multiple types of GBS strains. The challenge test results in CD1 mice demonstrated that the Ia-Sip group provided complete protection against lethal doses of bacteria and also showed cross-protection against type III strain. Our study demonstrates for the first time that Ia-Sip is immunogenic and provides serotype-independent protection in glycan conjugate vaccines, which also indicates Sip may serve as an excellent carrier protein for GBS glycan conjugate vaccines and provide cross-protection against multiple GBS strains.

Effects of Lily Polysaccharide on Immune Function and Intestinal Flora in Immunosuppressed Mice

The major goal of this study was to explore the effect of lily polysaccharides on immune function and intestinal flora in immunosuppressed mice. The immunosuppressed mouse model was established by treating mice with cyclophosphamide orally for 3 days and measuring post-treatment changes in immunological indexes. Also, the distribution of intestinal flora was determined by 16S DNA sequence analysis of cecal DNA. Compared with the cyclophosphamide group, there was a significant increase in the body weight and thymus index and a decrease in the liver index. The hepatocyte morphology, liver plate, and hepatic sinus arrangement of mice in the high- and low-concentration lily polysaccharide groups were corrected to varying degrees, and the contents of IgA and IgG in the serum of mice in the low-concentration lily polysaccharide group and the positive control group increased significantly. The contents of tumor necrosis factor-α and interleukin-6 in the colon decreased, while the contents of interleukin-10 increased significantly. The levels of aspartate transaminase, alanine aminotransferase, and malondialdehyde in the liver decreased significantly, while that of superoxide dismutase increased significantly. Compared with the blank group, lily polysaccharide increases the intestinal flora of immunosuppressed mice, mainly by increasing the abundance of beneficial bacteria such as Muribaculaceae (previously known as S24-7), Bacteroides, and Butyrimionas and decreasing the harmful bacteria such as Prevotella, Dorea, and Adlercreutzia.