Increased Risk of Thrombocytopenia and Death in Patients with Bacteremia Caused by High Alpha Toxin-Producing Methicillin-Resistant Staphylococcus aureus.

Alpha toxin (Hla) is a major virulence factor of Staphylococcus aureus that targets platelets but clinical data on Hla pathogenesis in bacteremia (SAB) is limited. We examined the link between in vitro Hla activity and outcome. Study isolates obtained from 100 patients with SAB (50 survivors; 50 non-survivors) were assessed for in vitro Hla production by Western immunoblotting in a subset of isolates and Hla activity by hemolysis assay in all isolates. Relevant demographics, laboratory and clinical data were extracted from patients' medical records to correlate Hla activity of the infecting isolates with outcome. Hla production strongly correlated with hemolytic activity (rs = 0.93) in vitro. A trend towards higher hemolytic activity was observed for MRSA compared to MSSA and with high-risk source infection. Significantly higher hemolytic activity was noted for MRSA strains isolated from patients who developed thrombocytopenia (median 52.48 vs. 16.55 HU/mL in normal platelet count, p = 0.012) and from non survivors (median 30.96 vs. 14.87 HU/mL in survivors, p = 0.014) but hemolytic activity of MSSA strains did not differ between patient groups. In vitro Hla activity of MRSA strains obtained from patients with bacteremia is significantly associated with increased risk for thrombocytopenia and death which supports future studies to evaluate feasibility of bedside phenotyping and therapeutic targeting.

Study on the effect of regulation of Cordyceps militaris polypeptide on the immune function of mice based on a transcription factor regulatory network.

BACKGROUND: The pathogenesis of the abnormality of the immune system is still not clear at present. Chemosynthetic drugs, human or animal immune products and microbiological drugs are used as the main drugs in clinics currently, but these drugs have different side effects. So researchers turned to safer natural products in order to find immunomodulatory active substances from natural products and their extracts. METHODS: Immunosuppressed mice were induced by cyclophosphamide and administered with Cordyceps militaris polypeptide (CMP) for the study on the effect of CMP on the immune function of mice and its mechanism. Based on the 1748 differential gene sets selected in our previous work, the transcription factors and their corresponding target genes were screened by integrating the TRED (Transcriptional Regulatory Element Database), a transcriptional factor-target gene regulatory network was constructed, then the role of transcription factors in the regulatory network was elucidated by statistically analyzing the key nodes, and finally, the correlation of network genes with diseases was analyzed by using the DAVID database. RESULTS: The results of animal experiments showed that CMP could increase the immune organ indexes, the number of white blood cells, the degree of delayed allergy and the content of hemolysin in the serum of mice. CMP was found to be involved in the regulation of immune function in mice through genes Kdr, Spp1, Ptgs2, Rel, and Smad3, and transcription factors Ets1, E2f2 and E2f1. E2F2 and E2F1 are members of the E2F family, so we speculated that the E2F family might play an important role, and its main regulatory pathways were the PI3K-Akt signaling pathway and TNF signaling pathway. CONCLUSION: CMP can improve the immunity of mice. CMP can regulate the immune function of mice through multiple genes and transcription factors, and may also play a role in immune-related diseases, such as cancer.

Comparison of ABO antibody titration, IgG subclasses and qualitative haemolysin test to reduce the risk of passive haemolysis associated with platelet transfusion.

BACKGROUND: One of the strategies used to reduce the risk of haemolysis due to ABO-minor incompatible platelet transfusions is to perform a screening test to identify group O donors with high titres of anti-A and anti-B. However, critical immunoglobulin M/ immunoglobulin G (IgM/IgG) titres remain unclear. OBJECTIVE: This study aimed to determine IgM titres of anti-A and anti-B in individual donor serum vs platelet products plasma and identify a possible association between IgM/IgG titres, haemolysin test and IgG subclasses in Brazilian blood donors from group O. METHODS: IgM anti-A and Anti-B titration tests were performed on single-donor serum and platelet product plasma by gel agglutination (GA) at room temperature. For IgG anti-A and anti-B titration, serum was first treated with 0.01 M dithiothreitol (DTT), and the test was performed by GA with incubation at 37°C. Dilution of 1:64 as the cut-off was considered for both IgM/IgG. The qualitative haemolysin test was performed in tube, adding AB fresh serum, with incubation at 37°C. IgG subclasses were determined by GA using specific monoclonal antibodies. RESULTS: An association between anti-A and anti-B IgM titres and haemolysin were demonstrated (P < .001). IgM titres in plasma samples from platelet components correlated to those in single-serum samples. IgG1/IgG3 subclasses were associated with total haemolysis and titres above 64, whereas IgG2/IgG4 subclasses were associated with the absence of haemolysis and titres below 64 (P < .001). CONCLUSION: Our data suggest that a value of 64 as a critical titre can be used as a screening test of anti-A and anti-B IgM to prevent transfusion reactions. This can be a safe and cost-effective approach for managing ABO-incompatible platelet transfusions.

Relieving Sore Throat Formula Exerts a Therapeutic Effect on Pharyngitis through Immunoregulation and NF-κB Pathway.

Relieving Sore Throat Formula (RSTF) is a formula approved by the China Food and Drug Administration and has been used for the treatment of pharyngitis in clinic for many years. However, the potential pharmacological mechanism still remains unknown. We combined multiple methods including bioinformatics data digging, network pharmacology analysis, and pathway analysis to predict the potential target of RSTF. We verified our in silico prediction results with an in vivo/vitro antibacterial effect test, mouse phagocytic index test, proliferation, transformation, and migration of mouse spleen lymphocytes. Alteration of NF-κB pathway was determined by Western blotting, immunofluorescence, and PCR. The in vivo experiments demonstrated that the RSTF could significantly relieve the symptoms of pharyngitis. A rat saliva secretion test showed that RSTF can effectively relieve the xerostomia symptom. A phenol red excretion test showed that RSTF has an eliminating phlegm effect. A hot plate method and granuloma experiment proved that RSTF also have analgesic and anti-inflammatory effects. In silico prediction demonstrates that 70 active compounds of RSTF were filtered out through ADME screening and 84 putative targets correlated with different diseases. Pathway enrichment analysis showed that the candidate targets were mostly related to the response to bacteria and immunity signalling pathways, which are known contributors to pharyngitis. Experimental results confirmed that RSTF exerted therapeutic effects on pharyngitis mainly by antibacterial effect and downregulation of NF-κB activities. It is demonstrated both in silico and in vivo/vitro that RSTF exerted therapeutic effects on pharyngitis mainly through an antibiotic effect and downregulation of NF-κB signalling pathway.

Protective effects of Ulva pertusa polysaccharide and polysaccharide­iron (III) complex on cyclophosphamide induced immunosuppression in mice.

A water-soluble polysaccharide was isolated from marine green algae Ulva pertusa and then chelated with iron to prepare the polysaccharide­iron (III) complex. The immunomodulatory activities of sulfated polysaccharide and polysaccharide­iron (III) complex were investigated through a mice immune-deficiency model. Cyclophosphamide (Cy) was utilized to establish mice immunodeficiency model. Both polysaccharide and polysaccharide­iron (III) complex were proved to promote the proliferation of lymphocyte and enhance the activities of mice macrophages. In mice serum, the levels of cytokines including TNF-α, IFN-γ and IL-10 restored and the contents of hemolysin were also found elevated after treatment with polysaccharide and its iron complex. Besides, it has been shown that both polysaccharide and polysaccharide­iron (III) complex increased the contents of Hb, RBC and HCT in mice blood, and the effect of iron complex was better. All these results suggested that Ulva pertusa polysaccharide could be developed as a healthy function food. It was also noteworthy that the polysaccharide­iron (III) complex showed no negative effect upon the immunomodulatory activity of polysaccharide. Instead, the polysaccharide­iron (III) complex showed excellent hematopoietic capacity perhaps due to the supplement of iron.

Glycosaminoglycan from Apostichopus japonicus induces immunomodulatory activity in cyclophosphamide-treated mice and in macrophages.

This study was designed to systematically elucidate the immunomodulation effect of glycosaminoglycan from Apostichopus japonicus (AHG) in cyclophosphamide (CY)-induced immunosuppression model and potential mechanism responsible for the activation of macrophages. The results showed that the treatment with AHG could increase natural killer (NK) cell cytotoxicity, carbon clearance and marker enzymes activities in CY-induced immunosuppression mice, indicating that the innate immunity experienced recovery to some extent. Moreover, CY-induced reductions in thymus and spleen indices, serum levels of cytokines, immunoglobulins and hemolysin, as well as the ratio of spleen lymphocyte subsets were recovered by AHG, suggesting that AHG could improve the adaptive immunity through cellular immunity and humoral immunity. Delightedly, it was found that AHG at 10 mg/kg body weight could restore the CY-induced immunosuppression in mice to normal level on both innate and adaptive immunity. Furthermore, AHG also promoted both the expression of NO, TNF-α, IL-6, IL-1ß, IL-18 and MCP-1 protein and related mRNA in macrophages. It was revealed that AHG activated macrophages through the phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor-B (NF-κB). In conclusion, AHG exerts remarkable immunomodulatory activities in both innate and adaptive immune system. These findings should have great value for further study on the immunopotentiating mechanisms of this biomacromolecule.

α-Haemolysin production, as a single factor, causes fulminant sepsis in a model of Escherichia coli-induced bacteraemia.

α-Haemolysin (HlyA) from uropathogenic Escherichia coli has been demonstrated to be a significant virulence factor for ascending urinary tract infections. Once the E. coli reach the well-vascularised kidneys, there is a high risk of bacteraemia and a subsequent septic host response. Despite this, HlyA has the potential to accelerate the host response both directly and via its ability to facilitate adenosine triphosphate release from cells. It has not been settled whether HlyA aggravates bacteraemia into a septic state. To address this, we used an E. coli strain in a model of acute urosepsis that was either transfected with a plasmid containing the full HlyA operon or one with deletion in the HlyA gene. Here, we show that HlyA accelerates the host response to E. coli in the circulation. Mice exposed to HlyA-producing E. coli showed massively increased proinflammatory cytokines, a substantial fall in circulating thrombocytes, extensive haematuria, and intravascular haemolysis. This was not seen in mice exposed to either E. coli that do not secrete HlyA or vehicle controls. Consistent with the massive host response to the bacteria, the mice exposed to HlyA-producing E. coli died exceedingly early, whereas mice exposed to E. coli without HlyA production and vehicle controls survived the entire observation period. These data allow us to conclude that HlyA is a virulence factor that accelerates a state of bacteraemia into fulminant sepsis in a mouse model.

Sea cucumber (Codonopsis pilosula) oligopeptides: immunomodulatory effects based on stimulating Th cells, cytokine secretion and antibody production.

This study aimed to investigate the immunomodulating activity of small molecule oligopeptides from sea cucumber (Codonopsis pilosula) (SOP) in mice. Seven assays were performed to determine the immunomodulatory effects, including splenic lymphocyte proliferation and delayed-type hypersensitivity assays (cell-mediated immunity), IgM antibody response of spleen to sheep red blood cells (SRBC) and serum hemolysin level assays (humoral immunity), the carbon clearance assay and the phagocytic capacity of peritoneal cavity phagocytes assay (macrophage phagocytosis), and the NK cell activity assay. Spleen T lymphocyte subpopulations, multiplex sandwich immunoassays of serum cytokine and immunoglobulin levels and enzyme-linked immunosorbent assays for small intestinal secretory immunoglobulin were performed to study the mechanism by which SOP affects the immune system. We found that SOP could improve immune functions in mice, which may be due to the enhancement of the functions of cell-mediated immunity, humoral immunity, macrophage phagocytosis and NK cell activity. From the cellular and molecular assays, we postulated that the immunomodulatory effects are most likely attributed to the stimulation of Th cells, cytokine secretion and antibody production.

TlyA protein of Mycobacterium leprae: a probable bio-marker of active infection.

The extent of pathogenicity of the mycobacterial infections depends on virulence factors that mediate survival inside macrophages. Virulence factors are generally believed to be specific for pathogenic species and mutated/non-functional in nonpathogenic strains. Mycobacterial TlyA can modulate the phagolysosome maturation pathway, immediately after entry into macrophages. Over-expression of open reading frame (ORF) ML1358 (tlyA) in tissues of leprosy patients by partial DNA chip and real time PCR analysis during active infection attracted our interest to explore the properties of this gene at molecular and serological levels, to understand its role in the host. Molecular properties were studied by cloning and expression of the corresponding gene in pASK-iba 43(þ) expression vector in E. coli and bioinformatics tools while sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and ELISA were applied to investigate the serological significance of rTlyA protein in different clinical states of leprosy. We observed that TlyA has a close relation among mycobacteria with specific protein domains in slow growing intracellular adapted pathogenic species. The presence of trans-membrane domains indicates its association to the cell membrane. The study revealed its highly significant sero-reactivity (P value , 0·001) in borderline lepromatous (BL) patients, and those with reversal reaction (RR) and erythema nodosum leprosum (ENL). Its role in active infection, association with the cell membrane, presence in pathogenic species and high sero-reactivity, suggested the tlyA gene as a strong disease progression marker.

On the mechanism of erythrocyte hemolysis induced by photooxidized psoralen.

Contemporary concepts on a possible mechanism of erythrocyte hemolysis induced by photooxidized psoralen - the medicinal photosensitizing furocoumarin - are reviewed. The hypothesis on the mechanochemical mechanism of hemolysis is considered in view of recent data on photoinduced aggregation in photooxidized psoralen solutions. Appropriate chemical structures of photoproduct hemolysins and aggregating photoproducts are discussed.

Prevalence of anti-A and anti-B hemolysis among blood group O donors in Lagos.

BACKGROUND: Group O donor blood is more readily available and is frequently used as universal red cell donor in our environment. The presence of hemolysins in the donors may however lead to hemolysis in the recipients. Attempts have been made to study the prevalence of hemolysins in various populations with results from our environment showing wide variation (20-80%). AIMS: To determine the prevalence and titer of anti-A and anti B hemolysins among blood donors at the Lagos University Teaching Hospital and compare results with that obtained elsewhere. Determine if the practice of transfusion of group O blood to nongroup O recipients is permissible in this environment. MATERIALS AND METHODS: Test for hemolysis was done using the standard tube method. Samples positive for hemolysis were then scored and titrated with the titers read visually and photometrically at 540 nm. RESULTS: Three hundred and fifty blood group O donors with age range 18-58 years and median age of 28 ΁ 8.4 years were enrolled in the study. The overall prevalence of anti-A and/or anti-B hemolysins obtained was 30.3%. Prevalence of anti-A and anti-B hemolysins only was 15.4% and 5.1% respectively whereas both anti-A and anti-B hemolysins were present in 9.7% donor samples. Though anti-A hemolysins were more prevalent than anti-B hemolysins, anti-B hemolysins had higher mean visual (6:7) and spectrophotometric titers (81:101). A visual titer of 8 and above which is considered significant was seen in 18.6% of donor samples. CONCLUSION: Anti-A and anti-B hemolysins exist in significant frequencies and titers among blood group O donors in Lagos. It is recommended that the use of group O donor blood for recipients who are non-O be discouraged. Clinical studies to determine the frequency and severity of hemolysis in non-group O recipients of blood group O are required.

Schisandra polysaccharide evokes immunomodulatory activity through TLR 4-mediated activation of macrophages.

Schisandra chinensis (Turcz.) Baill has been used in traditional Chinese medicine for centuries. Previous studies have shown that Schisandra polysaccharide (SCPP11) has robust antitumor activity in vivo. In this study, the immunomodulatory activity and mechanisms of action of SCPP11 were investigated further to reveal its mechanism of action against tumors. Results showed that SCPP11 increased the thymus and spleen indices, pinocytic activity of peritoneal macrophages, and hemolysin formation in CTX-induced immunosuppressed mice. Moreover, SCPP11 significantly increased immunoglobulin levels, cytokines levels in vivo and induced RAW264.7 cells to secrete cytokines in vitro. RAW264.7 cells pretreated with SCPP11 significantly inhibited the proliferation of HepG-2 cells. In addition, SCPP11 promoted both the expression of iNOS protein and of iNOS and TNF-α mRNA. TLR-4 is a possible receptor for SCPP11-mediated macrophage activation. Therefore, the data suggest that SCPP11 exerted its antitumor activity by improving immune system functions through TLR-4-mediated up-regulation of NO and TNF-α.

Purification, characterization and immunostimulatory activity of polysaccharide from Cipangopaludina chinensis.

In this study, we investigated the purification, preliminary characterization and immunostimulatory activity in vivo of polysaccharide from Cipangopaludina chinensis (CCPS). Firstly, crude CCPS was prepared by hot water extraction. And the crude CCPS was sequentially purified by chromatography of DEAE-52 and Sephadex G-100, resulting in two purified fractions of CCPS-1 and CCPS-2. We found the two fractions were homogeneous heteropolysaccharides mainly composed of rhamnose and glucose with the average molecular weight of 226 and 235 kDa, respectively. CCPS-2 was quite different from CCPS-1. It had much higher content of uronic acid and sulfuric radical. For immunostimulatory activity in vivo, crude CCPS could significantly increase the thymus and spleen indices, enhance the macrophage function, and increase the level of serum hemolysin in cyclophosphamide-treated mice, suggesting CCPS had a potent immunostimulatory activity and could be explored as a potential natural immunomodulatory agent.

Hemolysin from Escherichia coli induces oxidative stress in blood.

Hemolysin (HlyA) produced by some stains of Escherichia coli is considered to be an important virulence factor of those bacteria. On the other hand, reactive oxygen species (ROS) have been reported to be involved in the pathogenesis of different diseases via oxidative stress generation. The purpose of this study was to analyze the capacity of HlyA to induce oxidative stress in whole blood cultures (WBCs). To this end, ROS production, the damage induced in lipids and proteins, and the antioxidant defense system was evaluated in blood cultures exposed to low concentrations of HlyA. We found that HlyA increased the level of free radicals detected by chemiluminescence assay. Moreover, lipid peroxidation and protein damage was significantly increased in cultures treated with HlyA in comparation with those found in control cultures. On the other hand, a decrease in total antioxidant capacity of plasma and in the activity of superoxide dismutase (SOD) was observed in plasma from blood treated with HlyA. Collectively, our data demonstrate that low concentrations of E. coli hemolysin induced oxidative stress in WBCs with the induction of different oxidative damage biomarkers.

Effects of oral Bt-maize (MON810) exposure on growth and health parameters in normal and sensitised Atlantic salmon, Salmo salar L.

Responses to GM maize Bt-maize, MON810) expressing Cry1Ab protein from the soil bacterium Bacillus thuringiensis (Bt) in diets for both normal and immune-sensitised (with soyabean meal (SBM)-induced enteropathy) post-smolt Atlantic salmon were investigated following 33 and 97 d of exposure. Triplicate tanks of salmon were fed one of four diets, all containing 20% whole-kernel meal maize, either Bt-maize or its near-isogenic maternal line, without or with 15% extracted SBM inclusion. The fish fed Bt-maize utilised the feed less efficiently, as revealed by lower protein and mineral digestibilities and lower lipid and energy retention efficiencies. Higher intestinal weight, as well as increased interferon-γ and decreased sodium-glucose co-transporter mRNA expression, and a transient increase in T-helper cell presence, as measured by cluster of differentiation 4 (CD4) protein in the distal intestine (DI), may partly explain the lower nutrient digestibilities and retentions. The Bt-maize seemed to potentiate oxidative cellular stress in the DI of immune-sensitised fish, as indicated by increases in superoxide dismutase and heat shock protein 70 mRNA expression. The data suggest that Cry1Ab protein or other antigens in Bt-maize have local immunogenic effects in salmon DI. No systemic immune responses could be detected, as indicated by haematology, differential leucocyte counts, plasma clinical chemistry, as well as absence of Cry1Ab-specific antibodies and Cry1Ab protein in plasma. The responses to Bt-maize observed in the present study differed from results from earlier studies in salmon and other animals fed the same event Bt-maize. Longer-term experiments and more in-depth studies on intestinal physiology and immune responses are needed to evaluate health implications.

Flavone reduces the production of virulence factors, staphyloxanthin and α-hemolysin, in Staphylococcus aureus.

Staphylococcus aureus is a leading cause of nosocomial infections due to its resistance to diverse antibiotics. This bacterium produces a large number of extracellular virulence factors that are closely associated with specific diseases. In this study, diverse plant flavonoids were investigated to identify a novel anti-virulence compound against two S. aureus strains. Flavone, a backbone compound of flavonoids, at subinhibitory concentration (50 µg/mL), markedly reduced the production of staphyloxanthin and α-hemolysin. This staphyloxanthin reduction rendered the S. aureus cells 100 times more vulnerable to hydrogen peroxide in the presence of flavone. In addition, flavone significantly decreased the hemolysis of human red blood by S. aureus, and the transcriptional level of α-hemolysin gene hla and a global regulator gene sae in S. aureus cells. This finding supported the usefulness of flavone as a potential antivirulence agent against antibiotic-resistant S. aureus.

Polysaccharide extracted from Rheum tanguticum prevents irradiation-induced immune damage in mice.

AIM: To investigate the protective effect of purified fraction 1 polysaccharide extracted from Rheum tanguticum RTP1 on irradiation-induced immune damage in mice. METHODS: Kunming mice were randomly divided into five groups: normal group (NC), irradiation control group (IC), RTP1 low dose (200 mg/kg), middle dose (400 mg/kg) and high dose (800 mg/kg) groups. RTP1 was administered by the gastric route for 14 d, mice in the NC and IC groups being given by 0.9% sodium chloride solution in the same way. The mice in all groups except NC group were irradiated with 2.0 Gy6°Co γ-ray on the fourteenth day. Immune indives of non-specific immune function, cellular immunity and humoral immunity were assessed at the 24th hour after radiation. RESULTS: Compared with the IC group, the spleen index, thymus index, rate of carbon clearance, phagocytic function of macrophages, lymphocyte proliferation, hemolysin value of blood serum and NK activity were increased markedly (P < 0.05 or P < 0.05). CONCLUSION: RTP1 has an obvious protective effects on damage in γ-ray radiated mice.

Effects of feeding Bt MON810 maize to pigs for 110 days on peripheral immune response and digestive fate of the cry1Ab gene and truncated Bt toxin.

BACKGROUND: The objective of this study was to evaluate potential long-term (110 days) and age-specific effects of feeding genetically modified Bt maize on peripheral immune response in pigs and to determine the digestive fate of the cry1Ab gene and truncated Bt toxin. METHODOLOGY/PRINCIPAL FINDINGS: Forty day old pigs (n = 40) were fed one of the following treatments: 1) isogenic maize-based diet for 110 days (isogenic); 2) Bt maize-based diet (MON810) for 110 days (Bt); 3) Isogenic maize-based diet for 30 days followed by Bt maize-based diet for 80 days (isogenic/Bt); and 4) Bt maize-based diet (MON810) for 30 days followed by isogenic maize-based diet for 80 days (Bt/isogenic). Blood samples were collected during the study for haematological analysis, measurement of cytokine and Cry1Ab-specific antibody production, immune cell phenotyping and cry1Ab gene and truncated Bt toxin detection. Pigs were sacrificed on day 110 and digesta and organ samples were taken for detection of the cry1Ab gene and the truncated Bt toxin. On day 100, lymphocyte counts were higher (P<0.05) in pigs fed Bt/isogenic than pigs fed Bt or isogenic. Erythrocyte counts on day 100 were lower in pigs fed Bt or isogenic/Bt than pigs fed Bt/isogenic (P<0.05). Neither the truncated Bt toxin nor the cry1Ab gene were detected in the organs or blood of pigs fed Bt maize. The cry1Ab gene was detected in stomach digesta and at low frequency in the ileum but not in the distal gastrointestinal tract (GIT), while the Bt toxin fragments were detected at all sites in the GIT. CONCLUSIONS/SIGNIFICANCE: Perturbations in peripheral immune response were thought not to be age-specific and were not indicative of Th 2 type allergenic or Th 1 type inflammatory responses. There was no evidence of cry1Ab gene or Bt toxin translocation to organs or blood following long-term feeding.

An immunostimulatory polysaccharide (SCP-IIa) from the fruit of Schisandra chinensis (Turcz.) Baill.

A water-soluble polysaccharide named SCP-IIa was isolated from the water extract of the fruit of Schisandra chinensis (Turcz.) Baill by means of ethanol precipitation, deproteination, anion-exchange and gel-permeation chromatography. The molecular weight of SCP-IIa was ascertained via HPLC, and immuno-modulating effect was evaluated using the immunosuppressed model induced by cyclophosphamide. SCP-IIa was a homogeneous form of polysaccharide, with an average molecular weight of approximately 7700 Da. The detected parameters showed that SCP-IIa increased the thymus and spleen indices, as well as the pinocytic activity of the peritoneal macrophages in immunosuppressed mice. The splenocyte proliferation assay showed that SCP-IIa, in combination with Con A or LPS, positively affected splenocyte proliferation. Moreover, the polysaccharide promoted hemolysin formation. The results suggested that SCP-IIa was involved in immunomodulatory effects leading to the exploration for SCP-IIa as a potential immunostimulant.