Biomedical subjects

Hui Yan

Publications and source records attributed to Hui Yan.

At least 19 recordsLinked to original sources

PubMed2026

Identification and differential regulation of proteasome β family genes by viral infection and cytokines in grass carp (Ctenopharyngodon idella).

Proteasome β (PSMB) subunits are essential components of the proteasome complex and play important roles in antigen processing and immune regulation. In this study, we identified 14 Psmb genes in grass carp (Ctenopharyngodon idella), including seven constitutive Psmbs (Psmb1-7), three immunoproteasome genes (Psmb8-10), two thymoproteasome-related paralogs (Psmb11a and Psmb11b), and two telelost-specific members (Psmb12 and Psmb13). Comparative genomic analyses showed that grass carp Psmb genes are highly conserved in genomic organization, gene synteny, and predicted β-subunit-like protein structures, supporting the evolutionary conservation of the proteasome β-subunit family in fish. Phylogenetic and syntenic analyses further revealed lineage-specific expansion of immunoproteasome-related Psmb genes in teleost fish, with Psmb12 and Psmb13 likely derived from duplications of Psmb9 and Psmb10, respectively. Tissue expression analysis suggested functional divergence among duplicated Psmb members, as constitutive Psmbs were relatively enriched in the brain, whereas immunoproteasome-related and teleost-specific Psmbs were highly expressed in immune- and mucosa-associated tissues. Moreover, GCRV-I infection rapidly induced Psmb8-10 and Psmb11b expression in CIK cells. IFN-γ induced a broader set of Psmb genes than IFNa, whereas IL-10 selectively suppressed several Psmbs. Together, these findings highlight the evolutionary conservation, expansion, and immune-related diversification of the Psmb family in teleost fish.

Animals↗

PubMed2026

Integrated analysis of gut microbiota, serum metabolomics, and proteomics reveals novel associations with clinical symptoms in patients with cerebral infarction.

BACKGROUND: Cerebral infarction (CI) is a major cause of adult disability and mortality worldwide. Mounting evidence supports the critical role of the gut-brain axis in cerebrovascular disease progression. This study aimed to characterize the alterations in gut microbiota, serum metabolome, and serum proteome in patients with CI, and to identify multi-omics signatures associated with clinical symptoms. METHODS: A total of 20 CI patients and 20 healthy controls (HC) were enrolled. Fecal microbiota was profiled using 16 S rRNA gene high-throughput sequencing. Serum metabolomics and proteomics were analyzed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and data-independent acquisition (DIA) proteomics, respectively. Spearman correlation and multi-omics integration were applied to explore the associations among microbiota, metabolites, proteins, and clinical indicators. RESULTS: CI patients displayed significant gut microbiota dysbiosis, with a markedly lower gut microbiota health index (GMHI) and higher microbiota disorder index (MDI) compared with HC (P < 0.001). The genera g_norank_o_RF39 and Oxalobacter were significantly enriched in CI patients, whereas Clostridium_sensu_stricto_1 and Agathobacter were enriched in HC. Metabolomic analysis identified 445 differential metabolites, mainly involved in glycerophospholipid metabolism, phenylalanine metabolism, and caffeine metabolism. Proteomic analysis revealed 140 differentially expressed proteins linked to inflammatory responses, calcium signaling, and NF-κB signaling. Multi-omics integration showed that signature gut microbiota was strongly correlated (P < 0.005) with key serum metabolites and proteins implicated in CI pathogenesis. CONCLUSIONS: This integrated multi-omics study revealed distinct gut microbiota, serum metabolomic, and proteomic alterations in CI patients. The microbiota-metabolite-protein regulatory axes provide novel insights into the gut-brain axis in CI and may serve as potential diagnostic biomarkers or therapeutic targets.

Humans↗

PubMed2025

Identification of mitophagy-related biomarkers with immune cell infiltration in psoriasis.

BACKGROUND: Psoriasis is an inflammatory disorder characterized by scaly erythematous plaques and significant comorbidities. Recent studies have suggested that impaired mitophagy, the cellular mechanism for removing dysfunctional mitochondria, may contribute to the pathogenesis of psoriasis. METHODS: In this study, we analyzed bulk RNA sequencing data from 167 healthy individuals and 177 patients with psoriasis obtained from the Gene Expression Omnibus database (GSE30999 and GSE54456). Mitophagy-related genes were isolated using weighted gene co-expression network analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed and protein-protein interaction networks were constructed for the functional enrichment of genes associated with mitophagy. The correlations between genes associated with mitophagy, signaling pathways, and immune cell infiltration were analyzed. The potential diagnostic value of genes associated with mitophagy was evaluated using receiver operating characteristic (ROC) curves, which were validated in imiquimod-induced psoriatic skin lesions in mice. RESULTS: We identified 3,839 differentially expressed genes between healthy individuals and patients with psoriasis, and 23 genes were selected as hub genes showing a high correlation with mitophagy in psoriasis. GO and KEGG analyses revealed that hub and associated genes were significantly correlated with skin functions, such as epidermal development and keratinocyte differentiation. In addition, mitophagy-related genes were negatively associated with pro-inflammatory and pro-proliferation pathways in psoriasis. Among the immune cells, CD4+ T cells were most significantly affected by mitophagy-related genes. ROC analysis demonstrated that mitophagy-related genes, especially ACER1, C1ORF68, CST6, FLG2, GJB3, GJB5, GPRIN2, KRT2, and SPRR4 were potential biomarkers of psoriasis for use in diagnosis or treatment. CONCLUSIONS: Mitophagy-related genes play crucial roles in psoriasis and have potential use as biomarkers, providing insights into disease mechanisms and therapeutic targets. Further research may lead to the development of new strategies for psoriasis management.

Psoriasis↗

PubMed2006

Preparation and photocatalytic properties of YVO4 nanopowders.

YVO(4) photocatalysts with different grain sizes were obtained by annealing the YVO(4) nanopowders synthesized via microwave irradiation. The products were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), surface area and porosity analyzer, and ultraviolet-visible (UV-vis) spectrophotometer. Photocatalytic measurements showed that the YVO(4) nanopowders with grain size of about 5 nm possess superior photocatalytic properties in decolorization of methyl orange solution.

Azo Compounds↗

PubMed2006

Proteolytic cleavage of Livin (ML-IAP) in apoptotic melanoma cells potentially mediated by a non-canonical caspase.

BACKGROUND: Several inhibitor of apoptosis proteins (IAPs) are cleaved during apoptosis. Studies of the melanoma-associated IAP (ML-IAP) Livin, using recombinant molecules, have implicated both caspases 3/7 and the serine protease Omi/HtrA2 in its proteolytic cleavage. OBJECTIVE: To characterize the apoptotic cleavage of Livin in melanocytic cells, and evaluate the role of known proteases. METHODS: We assessed the capacity of a variety of stimuli to induce Livin cleavage in human melanoma cell lines and normal human melanocytes. The role of caspases and Omi was examined using caspase inhibitors and RNAi, respectively. A potential caspase substrate was further examined by site-directed mutagenesis. Deletion mapping was used to identify the cleavage site. RESULTS: Livin cleavage was observed in multiple human melanoma cell lines in response to a variety of apoptotic stimuli (UVB, 4-TBP, cisplatin, TNF, Bax), and not affected by the addition of various protease inhibitors or RNAi-mediated silencing of Omi/HtrA2. Livin cleavage induced by 4-TBP, but not UVB or cisplatin, was blocked by the pan-caspase inhibitor zVAD-fmk. Mutation of Asp52 to Glu in Livin did not affect cleavage, while either mutation of Asp52 to Ala, deletion of Asp52, or deletion of the adjacent region (residues 53-61) abrogated cleavage. CONCLUSION: Livin cleavage, induced by multiple apoptotic stimuli in melanoma cells, likely occurs in an Omi-independent fashion at residue 52 within its potential caspase substrate (DHVD52). However, relative insensitivity of the apoptotic cleavage to zVAD-fmk, or Asp52 to Glu mutation, suggests the involvement of a non-canonical caspase.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Pilot-scale in situ bioremedation of uranium in a highly contaminated aquifer. 2. Reduction of u(VI) and geochemical control of u(VI) bioavailability.

In situ microbial reduction of soluble U(VI) to sparingly soluble U(IV) was evaluated at the site of the former S-3 Ponds in Area 3 of the U.S. Department of Energy Natural and Accelerated Bioremediation Research Field Research Center, Oak Ridge, TN. After establishing conditions favorable for bioremediation (Wu, et al. Environ. Sci. Technol. 2006, 40, 3988-3995), intermittent additions of ethanol were initiated within the conditioned inner loop of a nested well recirculation system. These additions initially stimulated denitrification of matrix-entrapped nitrate, but after 2 months, aqueous U levels fell from 5 to approximately 1 microM and sulfate reduction ensued. Continued additions sustained U(VI) reduction over 13 months. X-ray near-edge absorption spectroscopy (XANES) confirmed U(VI) reduction to U(IV) within the inner loop wells, with up to 51%, 35%, and 28% solid-phase U(IV) in sediment samples from the injection well, a monitoring well, and the extraction well, respectively. Microbial analyses confirmed the presence of denitrifying, sulfate-reducing, and iron-reducing bacteria in groundwater and sediments. System pH was generally maintained at less than 6.2 with low bicarbonate level (0.75-1.5 mM) and residual sulfate to suppress methanogenesis and minimize uranium mobilization. The bioavailability of sorbed U(VI) was manipulated by addition of low-level carbonate (< 5 mM) followed by ethanol (1-1.5 mM). Addition of low levels of carbonate increased the concentration of aqueous U, indicating an increased rate of U desorption due to formation of uranyl carbonate complexes. Upon ethanol addition, aqueous U(VI) levels fell, indicating that the rate of microbial reduction exceeded the rate of desorption. Sulfate levels simultaneously decreased, with a corresponding increase in sulfide. When ethanol addition ended but carbonate addition continued, soluble U levels increased, indicating faster desorption than reduction. When bicarbonate addition stopped, aqueous U levels decreased, indicating adsorption to sediments. Changes in the sequence of carbonate and ethanol addition confirmed that carbonate-controlled desorption increased bioavailability of U(VI) for reduction.

Bacteria↗

PubMed2006

Activation of dual apoptotic pathways in human melanocytes and protection by survivin.

Apoptosis resistance in melanoma is a primary cause of treatment failure. Apoptotic pathways in melanocytes, from which melanoma arises, are poorly characterized. Human melanocytes were susceptible to apoptosis following exposure to UV radiation (UVB, 24-48 hours), 4-tert-butylphenol (4-TBP, 1-4 hours), and cisplatin (24-48 hours). These responses were associated with Bid cleavage, caspase activation (caspases 3, 8, and 9), mitochondrial depolarization and release of cytochrome c, Smac/DIABLO, and apoptosis-inducing factor (AIF), but not endonuclease G. The apoptotic responses and AIF release were caspase-independent, as they were not blocked by zVal-Ala-Asp(OMe)-fluoromethyl ketone (zVAD-fmk). While RNA interference-mediated knockdown of AIF protected melanocytes against apoptosis induced by serum withdrawal, apoptotic responses to UVB, cisplatin, and 4-TBP were not compromised by AIF knockdown, even in the presence of zVAD-fmk. Finally, adenoviral-mediated expression of Survivin, an inhibitor of apoptosis expressed in melanoma but not melanocytes, protected melanocytes against UVB-induced apoptosis. Survivin expression in melanocytes partially blocked caspase activation and release of mitochondrial release of AIF, cytochrome c, and Smac induced by UVB. These data indicate that multiple stimuli can activate both caspase-dependent and caspase-independent apoptotic pathways in melanocytes, and that endogenous expression of Survivin in melanoma may contribute to apoptosis resistance by multiple mechanisms.

Amino Acid Chloromethyl Ketones↗

PubMed2006

Thermoreversible protein hydrogel as cell scaffold.

A thermoreversible fibrillar hydrogel has been formed from an aqueous lysozyme solution in the presence of dithiothreitol (DTT). Its physical properties and potential as a tissue engineering scaffold have been explored. Hydrogels were prepared by dissolving 3 mM protein in a 20 mM DTT/water mixture, heating to 85 degrees C and cooling at room temperature. No gel was observed for the equivalent sample without DTT. The elastic nature of the gel formed was confirmed by rheology, and the storage modulus of our gel was found to be of the same order of magnitude as for other cross-linked biopolymers. Micro differential scanning calorimetry (microDSC) experiments confirmed that the hydrogel was thermally reversible and that gelation and melting occurs through a solid-liquid-like first-order transition. Infrared spectroscopy of the hydrogel and transmission electron microscopy studies of very dilute samples revealed the presence of beta-sheet-rich fibrils that were approximately 4-6 nm in diameter and 1 mum in length. These fibrils are thought to self-assemble along their long axes to form larger fibers that become physically entangled to form the three-dimensional network observed in both cryo-scanning electron microscopy (cryo-SEM) and small-angle neutron scattering (SANS) studies. The hydrogel was subsequently cultured with 3T3 fibroblasts and cells spread extensively after 7 days and stretched actin filaments formed that were roughly parallel to each other, indicating the development of organized actin filaments in the form of stress fibers in cells.

Animals↗

PubMed2006

The correlation evaluation of a tumor tracking system using multiple external markers.

The purpose of this study is to evaluate the correlations between external markers and internal targets for radiation therapy of lung cancer patients. Using an infrared camera system coupled with a clinical simulator, the simultaneous motions of multiple external markers and an internal target were obtained. The correlation between external and internal signals was analyzed using a cross-covariance function. A linear regression model was employed to generate a composite signal from multiple external markers in order to predict the internal target motion. The external and internal signals, and their correlations, demonstrated a wide range of variation with respect to marker location, motion dimension, and breathing pattern. The performance of the composite signal indicates that when more external signals were taken into account, the mean correlation between the composite signal and internal signal was improved. This implies that a combination of multiple external signals might be an improved way to predict internal target motion. Also, since the characteristics of respiratory signals can vary significantly, certain methods of preprocessing and external signal combination are necessary.

Artifacts↗

PubMed2006

[Expressions of Her-2, EGFR, PS-2 and ER in breast cancer and their clinical implications].

OBJECTIVE: To detect the expressions of human epidermal growth factor receptor 2 (Her-2), epidermal growth factor receptor (EGFR), presenilin 2 (PS-2) and estrogen receptor (ER) in breast cancer and discuss their clinical implications. METHODS: The expressions of Her-2, EGFR, PS-2 and ER were measured immunohistochemically in 108 patients with breast cancer. RESULTS: The positive expression rates of Her-2, EGFR, PS-2 and ER were 37.0%, 40.7%, 57.4% and 53.7% respectively in the breast cancer patients. The expression of Her-2 was not correlated with EGFR, but inversely correlated with PS-2 and ER. The expressions of Her-2 and EGFR, PS-2, ER were correlated with the histological grades (P<0.05), and Her-2, EGFR and ER expressions with lymph node metastasis (P<0.05). The expressions of Her-2, EGFR, PS-2 and ER did not correlate to the pathological types, patient's age and tumor size (P>0.05). CONCLUSION: Expressions of Her-2 and EGFR often suggests an unfavorable prognosis while expressions of PS-2 and ER suggest a more favorable one. Expressions of Her-2, EGFR, PS-2 and ER are useful prognostic factors in breast cancer patients.

Adult↗

PubMed2006

[Inhibition of rhodiola on the growth of EVC-304 cell line].

AIM: To observe the effect of rhodiola on human umbilical vein endothelial cell line EVC-304. METHODS: EVC-304 was cultured and divided into two groups: control group and rhodiola-treated group. Three days after treatment, cell survival rate-drug concentration curve was obtained by counting the survival cells, and cells in each group were stained by Wright's stain and observed under microscope. Cell cycle was determined by flow cytometry (FCM). RESULTS: The survival cells in rhodiola-treated group was much less than those in control group. More cells in rhodiola-treated group stayed in G(1) phase while less in S phase when compared with those in control group by FCM. CONCLUSION: Rhodiola can inhibit the growth of human endothelial cell line EVC-304, perhaps through inhibiting the proliferation of the cells. This may lay the foundation for the mechanism study and clinical application of rhodiola in prevention of pulmonary artery hypertension.

Cell Cycle↗

PubMed2005

Adaptive prediction of internal target motion using external marker motion: a technical study.

An adaptive prediction approach was developed to infer internal target position by external marker positions. First, a prediction model (or adaptive neural network) is developed to infer target position from its former positions. For both internal target and external marker motion, two networks with the same type are created. Next, a linear model is established to correlate the prediction errors of both neural networks. Based on this, the prediction error of an internal target position can be reconstructed by the linear combination of the prediction errors of the external markers. Finally, the next position of the internal target is estimated by the network and subsequently corrected by the reconstructed prediction error. In a similar way, future positions are inferred as their previous positions are predicted and corrected. This method was examined by clinical data. The results demonstrated that an improvement (10% on average) of correlation between predicted signal and real internal motion was achieved, in comparison with the correlation between external markers and internal target motion. Based on the clinical data (with correlation coefficient 0.75 on average) observed between external marker and internal target motions, a prediction error (23% on average) of internal target position was achieved. The preliminary results indicated that this method is helpful to improve the predictability of internal target motion with the additional information of external marker signals. A consistent correlation between external and internal signals is important for prediction accuracy.

Algorithms↗

PubMed2005

Natural humics impact uranium bioreduction and oxidation.

Although humic substances occur ubiquitously in soil and groundwater, their effect on the biological reduction of uranium(VI) and subsequent reoxidation of U(IV) is poorly understood. This study investigated the role of humics in enhancing the bioreduction of U(VI) in laboratory kinetic studies, in field push-pull tests, and in the presence or absence of metal ions such as Ca2+ and Ni2+, which are known to inhibit the biological reduction of U(VI). Results from laboratory experiments indicate that, under strict anaerobic conditions, the presence of humic materials enhanced the U(VI) reduction rates (up to 10-fold) and alleviated the toxicity effect of Ni2+ on microorganisms. Humic acid was found to be more effective than fulvic acid in enhancing the reduction of U(VI). Such an enhancement effect is attributed to the ability of these humics in facilitating electron-transfer reactions and/or in complexing Ca2+ and Ni2+ ions. Similarly, field push-pull tests demonstrated a substantially increased rate of U(VI) reduction when humic acid was introduced into the site groundwater. However, humics were also found to form complexes with reduced U(IV) and increased the oxidation of U(IV) (when exposed to oxygen) with an oxidation halflife on the order of a few minutes. Both of these processes render uranium soluble and potentially mobile in groundwater, depending on site-specific and dynamic geochemical conditions. Future studies must address the stability and retention of reduced U(IV) under realistic field conditions (e.g., in the presence of dissolved oxygen and low concentrations of complexing organics).

Biodegradation, Environmental↗

PubMed2005

Use of oxidoreduction potential as an indicator to regulate 1,3-propanediol fermentation by Klebsiella pneumoniae.

Anaerobic fermentation was relatively difficult to optimize due to lack of monitoring parameters. In this paper, a new method was reported using extracellular oxidoreduction potential (ORP) to monitor 1,3-propanediol (1,3-PD) biosynthesis process by Klebsiella pneumoniae. In batch fermentation, cell growth, 1,3-propanediol production and by-products distribution were studied at four different ORP levels: 10, -140, -190 and -240 mV. From the results, the ORP level of -190 mV was preferable, which resulted in fast cell growth and high 1,3-propanediol concentration. The NAD+/NADH ratio was determined at different ORP levels, and a critical NAD+/NADH ratio of 4 was defined to divide fermentation environments into two categories: relatively oxidative environment (NAD+/NADH>4) and relatively reductive environment (NAD+/NADH<4). The former was correlative with high 1,3-propanediol productivity and high specific growth rate. The mechanism of ORP regulation was discussed. It is suggested that ORP regulation of fermentation might be due to its influence on the ratio of NAD+/NADH, which determined metabolic flux. Furthermore, a batch fermentation of modulating ORP following a profile in different levels corresponding to different fermentation stage was tested. The 1,3-PD concentration was 22.3% higher than that of constant ORP fermentation at -190 mV. Therefore, ORP is a valuable parameter to monitor and control anaerobic fermentation production.

Anaerobiosis↗

PubMed2005

Bioreduction of uranium in a contaminated soil column.

The bioreduction of soluble uranium [U(VI)] to sparingly soluble U(IV) species is an attractive remedial technology for contaminated soil and groundwater due to the potential for immobilizing uranium and impeding its migration in subsurface environments. This manuscript describes a column study designed to simulate a three-step strategy proposed for the remediation of a heavily contaminated site at the U.S. Department of Energy's NABIR Field Research Center in Oak Ridge, TN. The soil is contaminated with high concentrations of uranium, aluminum, and nitrate and has a low, highly buffered pH (approximately 3.5). Steps proposed for remediation are (i) flushing to remove nitrate and aluminum, (ii) neutralization to establish pH conditions favorable for biostimulation, and (iii) biostimulation for U(VI) reduction. We simulated this sequence using a packed soil column containing undisturbed aggregates of U(VI)-contaminated saprolite that was flushed with an acidified salt solution (pH 4.0), neutralized with bicarbonate (60 mM), and then biostimulated by adding ethanol. The column was operated anaerobically in a closed-loop recirculation setup. However, during the initial month of biostimulation, ethanol was not utilized, and U(VI) was not reduced. A bacterial culture enriched from the site groundwaterwas subsequently added, and the consumption of ethanol coupled with sulfate reduction immediately ensued. The aqueous concentration of U(VI) initially increased, evidently because of the biological production of carbonate, a ligand known to solubilize uranyl. After approximately 50 days, aqueous U(VI) concentrations rapidly decreased from approximately 17 to <1 mg/L. At the conclusion of the experiment,the presence of reduced solid phase U(IV) was confirmed using X-ray absorption near edge structure spectroscopy. The results indicate that bioreduction to immobilize uranium is potentially feasible at this site; however, the stability of the reduced U(IV) and its potential reoxidation will require further investigation, as do the effects of groundwater chemistry and competitive microbial processes, such as methanogenesis.

Bacteria, Anaerobic↗

PubMed2005

Infection of human and non-human cells by a highly fusogenic primary CD4-independent HIV-1 isolate with a truncated envelope cytoplasmic tail.

Truncation of the envelope cytoplasmic tail has enabled FIV, SIV, and some laboratory HIV-1 strains to acquire broader cellular tropism and enhanced fusogenicity. Here we have characterized a primary CD4-independent HIV-1 isolate (92UG046-T8) with a truncated cytoplasmic tail that was able to infect and induce syncytia in primary lymphocytes from human, chimpanzee, and monkey, as well as CD4-negative cell lines from human and monkey. Increased syncytia were also noticeable with 293 cells expressing the cloned envelope from the 92UG046-T8 isolate suggesting envelope-mediated cellular fusion. Except pooled serum from HIV-1-infected individuals, monoclonal anti-envelope antibodies or antibodies/antagonists against CD4, CXCR4, and CCR5 were not able to prevent infection by the 92UG046-T8 isolate. This is the first report showing a primary HIV-1 variant with truncated cytoplasmic tail which is highly fusogenic and can infect a broad range of cells from human and non-human origins. In vivo evolution of similar HIV-1 mutants may have important implications in AIDS pathogenesis.

Animals↗

PubMed2005

Competitive complexation of metal ions with humic substances.

The surface complexation model was applied to simulate the competitive complexation of Ni, Ca and Al with humic substances. The presence of two types of binding sites in humic acid, carboxylic and phenolic functional groups, were assumed at both low and high pH conditions. Potentiometric titrations were used to characterize the intrinsic acidity constants of the two binding sites and their concentrations. It was found that the diffuse-layer model (DLM) could fit the experimental data well under different experimental conditions. Ni and Ca ions strongly compete with each other for reactions with the humic acid but Al showed little influence on the complexation of either Ni or Ca due to its hydrolysis and precipitation at pH approximately 5. The surface complexation constants determined from the mono-element systems were compared with those obtained from the multiple-element system (a mixture of the three metal ions). Results indicate little changes in the intrinsic surface complexation constants. Modeling results also indicate that high concentrations of Ca in the contaminated groundwater could strongly inhibit the complexation of Ni ions whereas an increase in pH and the humic concentration could attenuate such competitive interactions. The present study suggests that the surface complexation model could be useful in predicting interactions of the metal ions with humic substances and potentially aid in the design of remediation strategies for metal-contaminated soil and groundwater.

Adsorption↗

PubMed2005

[Soluble expression and characterization of the immunoreactive multiepitope antigen of Toxoplasma gondii in E.coli].

OBJECTIVE: To obtain soluble expression product of immunoreactive recombinant multiepitope antigen of Toxoplasma gondii from E.coli. METHODS: The gene encoding the multiple epitopes (MEG) of Toxoplasma gondii was amplified by PCR from the original plasmid containing MEG gene and cloned into the prokaryotic soluble expression vector pET32a. After identification by enzyme digestion and sequencing, the positive recombinant plasmid pET32a-MEG was transformed into BL21(DE3), which was induced with IPTG for expression of the target antigen. The relative molecular mass, solubility and antigenicity of the expression products were analyzed by SDS-PAGE and Western blotting. RESULTS: The recombinant expression plasmid pET32a-MEG was successfully constructed and the highly efficient expression of the antigen was achieved after IPTG induction of E.coli. Improvement of the induction condition increased the expression product which accounted for about 28% of the total bacterial protein. The target protein, with good solubility and a relative molecular mass of about 31 000, was purified by immobilized metal affinity chromatography (Ni-NTA resin) and could be well recognized by mouse and rabbit antisera derived by infection of the animals with Toxoplasma gondii B36 and RH, respectively. CONCLUSION: The recombinant multiepitope antigen has good antigenicity and potential value in diagnosis and vaccine development of toxoplasmosis.

Animals↗