Optimization on preparation condition of epimedium polysaccharide liposome and evaluation of its adjuvant activity

The aim of this strategy was to investigate whether the adjuvant activity of epimedium polysaccharide (EPS) could be further enhanced after encapsulated with liposome. In preparation of EPS liposome (EPSL) test, an orthogonal L₉ (3⁴) test design was used to optimize the preparation condition of EPSL. In adjuvant activity test, 350 14-day-old chickens were randomly assigned to 7 groups and vaccinated with Newcastle disease (ND) vaccine. Simultaneously, the chickens in experimental groups were injected with EPSL at three doses, EPS and blank liposome, respectively. The activity of lymphocytes proliferation, titer of serum antibody and concentrations of cytokines were determined. Results showed that the optimal preparation condition of EPSL was that ratio of drug to lipid, ratio of soybean phospholipid to cholesterol, ultrasonic time, and water bath temperature were 1:30, 4:1, 10 min and 40 °C, respectively. EPSL could significantly enhance the immune response of ND vaccine and promote cytokines secretion, and its high dose possessed the best efficacy. These findings indicated that liposome encapsulation could significantly improve the adjuvant activity of EPS.     

Liposome and epimedium polysaccharide-propolis flavone can synergistically enhance immune effect of vaccine

Three preparations of epimedium polysaccharide-propolis flavone immunopotentiator (EPI), EPI liposome, EPI suspension and EPI watery solution were prepared. In immune response test, their adjuvanticities were compared in 14-day-old chickens vaccinated with Newcastle disease (ND) vaccine. In immune protection test, the effects of the three preparations on Newcastle disease virus (NDV) infection were compared in chickens vaccinated with ND vaccine then challenged with NDV. The results displayed that EPI liposome could enhance the antibody titer, T lymphocyte proliferation and the concentrations of interferon-γ and interleukin-6, when compared with the other two preparations. In EPI liposome group, the antibody titers, lymphocyte proliferation and protective rate were the highest, while the mortality and morbidity were the lowest, in comparison with the other groups. These results indicated that liposome could enhance the immune effect of EPI on ND vaccine and would be expected as the suitable dosage form of this immunopotentiator.     

Astragalus polysaccharide and sulfated epimedium polysaccharide synergistically resist the immunosuppression

The immunoenhancement of compound polysaccharides, APS-sEPS composed with astragalus polysaccharide (APS) and sulfated epimedium polysaccharide (sEPS), was observed in immunosuppressed model chicken induced by cyclophosphamide (Cy). 11-day-old chickens were injected with Cy once a day for three successive days except vaccine control group. At day-14-old, all chickens were vaccinated with ND vaccine, and in experimental groups simultaneously administrated with APS-sEPS at three dosages, APS and sEPS once a day for three successive days. On days 7, 14, 21 and 28 after the administration, the peripheral T-lymphocyte proliferation, serum antibody titers, IFN-γ, IL-2, IgG and IgM were determined. The results displayed that APS-sEPS could overcome Cy-induced immunosuppression, significantly promote T-lymphocyte proliferation and raised serum antibody titers, IFN-γ, IL-2, IgG and IgM levels, its high and medium doses were superior to single APS or sEPS. This demonstrated that APS and sEPS could synergistically resist the immunosuppression and APS-sEPS was an effective immunopotentiator.     

Specific immunoglobulin response in mice immunized with porins and challenged with Salmonella typhi

Specific antiporin antibody (IgG, IgM, and IgA) response was studied in control, infected, immunized-infected, and immunized mice. The activity of specific IgG immunoglobulins was found to be the highest in immunized and immunized-infected groups in which 87.5% protection had been observed by laboratory potency test in mice; the next-highest activities were those of IgM and IgA immunoglobulins. However, in the infected group the activity of specific IgM and IgG immunoglobulins was almost similar.     

Sulfated modification can enhance the immune-enhancing activity of lycium barbarum polysaccharides

In test in vitro, four sulfated lycium barbarum polysaccharides (sLBPSs) with different degrees of sulfation (DS), sLBPS_0.7, sLBPS_1.1, sLBPS_1.5 and sLBPS_1.9, were added into cultured chicken peripheral lymphocytes and the changes of lymphocytes proliferation were compared by MTT assay taking the non-modified LBPS as control. Two sLBPSs with better efficacy, sLBPS_1.5 and sLBPS_1.9 were selected. In test in vivo, one hundred 14-day-old chickens were averagely divided into five groups randomly. The chickens except blank control group were vaccinated with Newcastle disease vaccine, repeated vaccination at 28 days old. At the same time of the first vaccination, the chickens in three experimental groups were injected with 0.5 mL of sLBPS_1.5, sLBPS_1.9 and LBPS at 4 mg mL⁻¹, in vaccination control group, with 0.5 mL of physiological saline, once a day for three successive days. On days 7, 14, 21 and 28 after the first vaccination, the changes of peripheral lymphocytes proliferation and serum HI antibody titer were determined. The result showed that two sLBPSs could significantly promote lymphocytes proliferation and enhance serum antibody titer. These results indicated that sulfated modification could enhance the immune-enhancing activity of LBPS, which there was a certain relativity with the DS of sulfated polysaccharide. sLBPS_1.5 possessed the best efficacy and would be expected as the component drug of a new-type immunopotentiator.     

Optimization on condition of glycyrrhetinic acid liposome by RSM and the research of its immunological activity

The aim of this study is to prepare glycyrrhetinic acid liposome (GAL) and optimize the preparation condition and to investigate further whether liposome could promote the immunological activity of glycyrrhetinic acid (GA). GAL was prepared using a film-dispersion method and the preparation conditions of GAL were optimized with response surface methodology (RSM). Moreover, GAL prepared under the optimal preparation conditions was added into chicken's T and B lymphocytes in vitro. The optimal preparation conditions for GAL by response surface methodology was as follows: ratio 9:1, soybean phospholipid cholesterol (w/w) 2.5:1 and water bath temperature 31 °C. Under these conditions, the experimental encapsulation efficiency of GAL was 83.46 ± 0.55%, which was close with the predicted value. Therefore, the optimized preparation condition is very reliable. The results showed that GAL could significantly promote T and B lymphocytes proliferation singly or synergistically with PHA and LPS and the concentration of immunoglobulins G (IgG) and immunoglobulins M (IgM). These results indicated that liposome could significantly improve the immunological activity of GA and drug action of GA. GAL demonstrates the significant immunological activity, which provides the theoretical basis for the further experiment in vivo.     

Fractionation of immunoglobulins by liquid-liquid partition chromatography in aqueous two-phase systems

In this paper we show that although immunoglobulins are easily precipitated in solutions containing polyethylene glycol (PEG), especially at pH's where the conformation of the proteins should be close to native, human and rabbit IgG can be solubilized in aqueous dextran/PEG two-phase systems containing glycine and sodium chloride at pH 7.0 and that human IgA and IgM can be solubilized in such systems if the pH is increased to 9.0. Liquid-liquid partition chromatography (LLPC) on Li-ParGel was used to separate immunoglobulins into subfractions. Human IgG, IgM, and IgA all gave three peaks in the system used. These results indicate the possibility of separating different classes of immunoglobulins with this method. Specific IgG antibodies isolated from a rabbit antiserum against human serum proteins gave only two peaks in the LLPC system while the total IgG population gave three, as did human IgG. Thus, partitioning of immunoglobulins seems to be related to antibody activity.     

Ordering of antibodies, that react with cardiac muscle fiber and interstitial connective tissue antigens, in different immunoglobulin classes

Sera of patients suffering from rheumatic diseases and myocarditis were examined on the sections of human and bovine myocardial tissue by indirect immunofluorescence with the use of pure IgG antibodies or monospecific sera against IgG, IgA and IgM. It was shown that antibodies reacting with different myofibers and interstitial connective tissue of the heart belong to the main immunoglobulin classes (IgG, IgA and IgM). There was a significant predominance of IgG antibodies as shown by the frequency of their detection and by the titer height. The predominance of antibodies to certain classes of immunoglobulins did not correlate with a specific disease entity. The frequency of detecting antibodies to a certain immunoglobulin class was in good agreement with the time of the disease onset. Moreover, the frequency of positive reactions due to IgG, IgA, and IgM antibodies correlated with the level of the appropriate immunoglobulins in the test sera.     

Toxoplasma IgG and IgA,but not IgM,antibody titers increase in sera of immunocompetent mice in association with proliferation of tachyzoites in the brain during the chronic stage of infection

Toxoplasma IgG and IgA, but not IgM, antibody titers were significantly higher in immunocompetent mice with cerebral proliferation of tachyzoites during the chronic stage of infection than those treated with sulfadiazine to inhibit the parasite growth. Their IgG and IgA antibody titers correlated significantly with the amounts of tachyzoite-specific SAG1 mRNA in their brains. In contrast, neither IgG, IgA, nor IgM antibody titers increased following two different doses of challenge infection in chronically infected mice. Increased antibody titers in IgG and IgA but not IgM may be a useful indicator suggesting an occurrence of cerebral tachyzoite growth in immunocompetent individuals chronically infected with Toxoplasma gondii.     

IgG and IgM responses in high and low antibody-selected lines of chickens

Kinetics of IgG and IgM as measured by 2-mercaptoethanol-resistant (MER) and susceptible (MES) antibodies to sheep erythrocytes, respectively, were determined as correlated responses in lines of chickens selected for high (HA) and low (LA) antibody response to sheep erythrocytes. Primary response patterns for total, MER, and MES antibody differed according to the genetic line. Total antibody increased rapidly, peaked, and persisted at moderate levels in line HA, whereas both peak and persistency were lower in line LA. Levels of MES peaked and then declined in line HA chickens but persisted at low levels throughout in line LA. Titers of MER antibody were considerably greater in line HA than in line LA both on an absolute basis and as a proportion of total antibody titer. Secondary total titers were greater at five days after injection than at three days and greater for line HA than for line LA chicks. The pattern observed for MER and MES in line LA was similar to that for total antibody, as was MER in line HA. For MES the pattern was reversed in line HA.     

Effects of Selenylation Modification on Immune-Enhancing Activity of Garlic Polysaccharide

The garlic polysaccharide was modified by HNO₃-Na₂SeO₃ method according to orthogonal design L₉(3⁴) to obtain nine selenizing garlic polysaccharides, sGPS₁-sGPS₉. Their effects on chicken peripheral lymphocytes proliferation in vitro were compared by MTT assay. The results showed that sGPSs could significantly promote lymphocytes proliferation, sGPS₃, sGPS₅ and sGPS₆ presented stronger efficacy. In vivo experiment, 14-day-old chickens were injected respectively with sGPS₃, sGPS₅ and sGPS₆ when they were vaccinated with ND vaccine taking unmodified GPS as control. The results showed that three sGPSs could significantly promote lymphocyte proliferation, enhance serum antibody titer, IFN-γ and IL-2 contents. These results indicated that selenylation modification could significantly enhance the immune-enhancing activity of GPS, sGPS₆ possessed the best efficacy and could be as a candidate drug of immunoenhancer. Its optimal modification conditions were 400 mg of sodium selenite for 500 mg of GPS, reaction temperature of 70°C and reaction time of 6 h.     

Isotype specific immune responses in murine experimental toxocariasis

In this work, a murine experimental model of toxocariasis has been developed in BALB/c, C57BL/10 and C3H murine strains orally inoculated with 4,000 Toxocara canis embryonated eggs, in order to investigate the isotype-specific immune responses against excretory-secretory antigens from larvae. T. canis specific IgG+M, IgM, IgG, IgA, IgG1, IgG2a and IgG3 were tested by ELISA. The dynamics of the specific immunoglobulins (IgG+IgM) production showed a contrasting profile regarding the murine strain. Conversely to the results obtained with the IgM isotype, the IgG antibody class showed similar patterns to those obtained with IgG+IgM antibodies, only in the case of the BALB/c strain, being different and much higher than the obtained with IgG+IgM antibodies, when the C3H murine strain was used. The antibodies IgG+IgM tested in BALB/c and C57BL/10 were both of the IgM and IgG isotypes. Conversely, in the C3H strain only IgG specific antibody levels were detected. The IgG1 subclass responses showed a similar profile in the three murine strains studied, with high values in BALB/c, as in the case of the IgG responses.     

IgM-mediated enhancement of in vivo anti-sheep erythrocyte antibody responses: isotype analysis of the enhanced responses

The direct splenic anti-sheep erythrocyte (anti-SRBC) responses as well as the serum IgG1, IgG2a, IgG2b, and IgG3 anti-SRBC responses of CBA/CaJ mice were monitored 4-35 days after immunization with: (1) a suboptimal dose of SRBC, (2) a suboptimal dose of SRBC plus monoclonal IgM anti-SRBC, or (3) a high dose of SRBC. The direct plaque-forming cell (PFC) responses of mice in treatment group 2 were significantly higher than those in group 1 but similar to the responses in group 3. The serum anti-SRBC antibody responses of all IgG subclasses were significantly enhanced by IgM anti-SRBC and were generally even higher than the responses obtained with high doses of SRBC. The relative proportions of each serum IgG subclass were similar in all three groups. These data suggest that the enhancement of suboptimal anti-SRBC antibody responses by IgM anti-SRBC extends through IgM and all of the IgG subclasses and, further, that the isotype profile in antibody-enhanced responses is similar to that obtained with high doses of SRBC.     

Serological Study of Bartonella henselae in Cat Scratch Disease in Japan

It has become clear that Bartonella henselae is a common cause of cat scratch disease (CSD). The indirect fluorescence antibody (IFA) test for detection of IgG and IgM antibodies to B. henselae concerning CSD showed that 5 (50%) of 10 patients with CSD had a serum IgG antibody titer of 1:128 or more and that 2 (20%) patients had a serum IgM antibody titer of 1:20 or more. One of 7 asymptomatic members of patients' families (14%) had IgG antibody to B. henselae at a titer of 1:256. IgM antibody to B. henselae was not detected in sera from the patients' families. Both IgG and IgM antibodies to B. henselae were not detected in sera from the healthy control group. These data suggest that B. henselae may be a cause of CSD in Japan.     

The comparison of immune-enhancing activity of sulfated polysaccharidses from Tremella and Condonpsis pilosula

Based on our previous research, four sulfated polysaccharide (sPSs) from Tremella and Condonpsis pilosula, sTPS_tp, sTPS_70c, sCPPS_tp and sCPPS_50c, were prepared and their effects on splenic lymphocytes proliferation in vitro and the immune response of ND vaccine in chicken were compared taking the unmodified polysaccharide (uPS) TPS_tp as control. The results showed that four sPSs could significantly or numerically stimulate splenic lymphocyte proliferation singly or synergistically with LPS in vitro, sTPS_70c and sCPPS_tp demonstrated better effect; promote peripheral lymphocytes proliferation and enhance serum HI antibody titer in chickens vaccinated with ND vaccine, the actions of sPSs were stronger than that of uPS, and sTPS_70c at medium dosage presented the best efficacy. These indicated that sulfation modification could improve the immune-enhancing activity of TPS and CPPS, sTPS_70c possessed the strongest activity and would be expected as a component of new-type immunopotentiator.     

Comparative evaluation of the functional activity of different immunoglobulin classes in cholera]

The immunological activity of specific immunoglobulins in different forms of cholera infection was studied with the use of the indirect immunofluorescent method. The forms of cholera infection were shown to be related to the physico-chemical spectrum of antibodies: patients with the pronounced clinical symptoms of cholera produced serum IgM, including antigen -- antibody complex, more actively and in a greater amount; patients with faintly pronounced and asymptomatic infection produce highly active IgG. The competitive action of immunoglobulins of different classes in their simultaneous reaction with O antigen of Vibrio cholerae is shown. The mechanism of the competitive action of different immunoglobulin classes is supposed to play some role in the process of the sanation (with highly active IgM) or detoxication (with highly active IgG) of the organism.     

Anti-IgD enhancement of primary antibody responses in rats

The role of membrane IgD in immune responses was examined by treating adult rats with anti-IgD. Anti-IgD when administered to rats in conjunction with optimal or suboptimal doses of either SRBC, a T-dependent antigen, or DNP-Ficoll, a T-independent antigen, enhanced the antibody responses. The greatest enhancement was obtained when anti-IgD was administered before the antigen. The effects of anti-IgD on antibody responses to SRBC were: (i) significant antibody responses to suboptimal antigen concentrations; (ii) greater antibody responses to optimal antigen concentrations; (iii) accelerated antibody responses; (iv) an early shift from IgM to IgG antibodies; (v) prolonged antibody responses. Similar effects on the immune response to DNP-Ficoll were observed with the exception that all antibodies were 2ME sensitive (IgM). These results suggest that an anamnestic type of immune response can be induced in anti-IgD-treated rats when given a primary antigen exposure. Injection of anti-IgD without SRBC or DNP-Ficoll induces B-cell proliferation without detectable antibody production to these antigens, indicating at least two signals are required for the enhanced antibody responses.     

The establishment of human anti-TROP2 antibody IgG and its inhibition function on pancreatic cancer cell proliferation

On the basis of anti-TROP2 Fab antibody, this study seek to construct a eukaryotic expression system of human anti-TROP2 antibody IgG, and to analyse the inhibition function of human anti-TROP2 antibody IgG in the cell proliferation of pancreatic cancer. The heavy and light chain genes of anti-TROP2 antibody were amplified respectively to establish the recombinant expression vector of human anti-TROP2 antibody IgG, named pWS-anti-TROP2. The human anti-TROP2 antibody IgG was obtained through transfecting the plasmids into the CHO dhfr^- cell line, selecting the monoclonal cell strains with high amounts of antibody expression by MTX screening and applying Protein G affinity in purification. The identification and immunologic activity of human anti-TROP2 antibody IgG were researched by Western Blot,SDS-PAGE, ELISA, immunofluorescence assay and flow cytometry method (FCM). MTT assay was conducted to analyse the inhibition effect of human anti-TROP2 antibody IgG on BxPC3 cell proliferation. The human anti-TROP2 antibody IgG eukaryotic expression system was established successfully to express human anti-TROP2 antibody IgG, in which the molecular weight of heavy chain and light chain were consistent with expectation, and it could specifically combine with TROP2 protein, the antibody titer reached 1:6,400. The MTT assay results indicated that human anti-TROP2 antibody IgG had a significant effect on inhibiting the proliferation of BxPC3 cell, and the inhibition function can be gradually increased with improved antibody dose and prolonged time. In the study, the human anti-TROP2 antibody IgG eukaryotic expression system was constructed successfully, the antibody could specifically bind to TROP2 protein on the surface of pancreatic cancer cells, and it is shown to have a significant inhibitory action in pancreatic cancer cell proliferation.     

The mobility of concanavalin A receptors and surface immunoglobulins on rat hepatocyte plasma membranes

Lateral mobilities of lectin receptors and surface immunoglobulins were measured in plasma membranes of hepatocytes prepared by smearing small pieces of rat liver tissue and then using the fluorescence recovery after photobleaching (FRAP) technique. Smears were treated with various doses of fluorescein isothiocyanate (FITC) conjugated concanavalin A (ConA), succinylated ConA (SConA), wheat germ agglutinin (WGA), and soybean agglutinin (SBA), as well as with rabbit anti-rat IgG (RARa/IgG) and goat anti-rat IgM(Fc) (GARa/IgM(Fc] antisera. 10 micrograms/ml ConA and SConA concentrations and a 55 X dilution of the GARa/IgM(Fc) antiserum were found to be suitable for measuring the lateral mobilities dependent on age. Diffusion constant and mobile fractions of receptor complexes were measured in different age groups of female Fisher rats (from 1 to 26 month-old). The FRAP measurements revealed that at least two major receptor sites can be distinguished in cell membranes of compact tissue (similar to the cultured and isolated cells), forming a mobile and an immobile fraction. The mobile fractions of both the lectin receptors and the surface immunoglobulins tended to decrease with age, while the age differences of the diffusion constants were not statistically significant. The observed alterations could be due to the covalent crosslinking of the mobile receptors to immobile patches and/or to the retardation of free diffusion by the cytoskeleton, dependent on age.     

Porcine lactoferrin as feedstuff additive elevates avian immunity and potentiates vaccination

In this study, recombinant porcine lactoferrin (PLF) was used as feedstuff additive to investigate the effects of peripheral lymphocyte proliferation and serum antibody titers in chickens vaccinated against the infectious bursal disease (IBD) virus. Treatment groups were fed three doses of PLF powder in their diet (0.5, 1.0, and 2.0% w/w), and the IBD vaccine was administrated at 1 and 3 weeks of age. At 8, 12, and 16 weeks after vaccination, serum IBD antibody titers were measured via the micro-method and T cell proliferation rates were evaluated. The results revealed that a high dose of PLF led to significant increases in serum IgA, IgG and IBD-specific antibody titers (P < 0.05). PLF administration, at either low or high doses, enhanced the expression of IFN-γ and IL-12 in chicken T lymphocytes. These results suggest that PLF enhances cell-mediated immunity and augment the ability of IBD vaccination to strengthen subsequent anti-viral responses.