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Alternative splicing (AS) is an evolutionarily conserved mechanism that removes introns and ligates exons to generate mature messenger RNAs (mRNAs), extremely improving the richness of transcriptome and proteome. Both mammal hosts and pathogens require AS to maintain their life activities, and inherent physiological heterogeneity between mammals and pathogens makes them adopt different ways to perform AS. Mammals and fungi conduct a two-step transesterification reaction by spliceosomes to splice each individual mRNA (named cis -splicing). Parasites also use spliceosomes to splice, but this splicing can occur among different mRNAs (named trans -splicing). Bacteria and viruses directly hijack the host's splicing machinery to accomplish this process. Infection-related changes are reflected in the spliceosome behaviors and the characteristics of various splicing regulators (abundance, modification, distribution, movement speed, and conformation), which further radiate to alterations in the global splicing profiles. Genes with splicing changes are enriched in immune-, growth-, or metabolism-related pathways, highlighting approaches through which hosts crosstalk with pathogens. Based on these infection-specific regulators or AS events, several targeted agents have been developed to fight against pathogens. Here, we summarized recent findings in the field of infection-related splicing, including splicing mechanisms of pathogens and hosts, splicing regulation and aberrant AS events, as well as emerging targeted drugs. We aimed to systemically decode host-pathogen interactions from a perspective of splicing. We further discussed the current strategies of drug development, detection methods, analysis algorithms, and database construction, facilitating the annotation of infection-related splicing and the integration of AS with disease phenotype.
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Animales , Empalme Alternativo/genética , Empalme del ARN , Empalmosomas/metabolismo , ARN Mensajero/metabolismo , Enfermedades Transmisibles/genética , Mamíferos/metabolismoRESUMEN
【Objective】 To investigate the preventive and therapeutic effects of cepharanthine on nasopharyngeal carcinoma rats through the mitogen-activated protein kinase (MAPK)/extracellular signal regulated kinase (ERK) signaling pathway and its effect on Survivin and X-linked inhibitor of apoptosis protein (XIAP), and B-cell lymphoma/leukemia-2 (Bcl-2). 【Methods】 A rat model of nasopharyngeal carcinoma was established by subcutaneous injection of dinitrosopiperazine (DNP). Then the rats were randomly divided into model group, stephenine group, activator group, inhibitor group, and control group. Interleukin (IL)-1β and IL-18 levels in nasal lavage fluid were detected, HE staining was used to observe pathological changes of nasal mucosa, TUNEL method was used to observe cell apoptosis of nasal mucosa, Western blotting was used to detect ERK, p-ERK, Survivin, XIAP, Bcl-2, Bcl-2 associated X protein (Bax) protein expression of nasal mucosa. 【Results】 The histopathological changes of rat nasal mucosa in stephenine group, activator group and inhibitor group were significantly better than those in model group; the improvement in activator group was worse. Compared with model group, the body mass, Survivin, XIAP, and Bcl-2 protein expressions increased, while the levels of IL-1β and IL-18, the rate of apoptosis and p-ERK1/2 and Bax protein expressions decreased in cephalothin group, activator group and inhibitor group (P<0.05). Compared with cephalothin group, in activator group the body mass, Survivin, XIAP, and Bcl-2 protein expressions decreased, whereas IL-1β and IL-18 levels, the rate of apoptosis, and p-ERK1/2 and Bax protein expressions increased. In inhibitor group, the body mass, Survivin, XIAP, and Bcl-2 protein expressions increased, IL-1β and IL-18 levels, the rate of apoptosis, and p-ERK1/2 and Bax protein expressions decreased (P<0.05). 【Conclusion】 Stephaneine has a certain preventive effect on nasopharyngeal carcinoma rats, which may play an effect by inhibiting the MAPK/ERK pathway.
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The osteoporotic fracture is characterized by difficult treatment and poor prognosis. The studies of bone biology show that bone microenvironment changes during osteoporotic fractures，such as changes in immune factors，abnormal chemotaxis and differentiation of mesenchymal stem cells（MSCs），decreased estrogen secretion and receptor down-regulation and decreased mechanical sensitivity，which affect the fracture healing process. Current studies have shown that by improving the phenotypic polarization of macrophages，enhancing the chemotactic osteogenic activity of MSCs，supplementing estrogen and improving the biomechanical properties of bone can remodel the balance of bone microenvironment，thereby effectively improve the bone quality. The authors explore the effect and mechanism of bone microenvironment on healing of osteoporotic fractures from the perspectives of changes in bone microenvironment and imbalance of bone microenvironment that affect fracture healing and methods of bone microenvironment reconstruction，so as to provide new ideas for clinical treatment of osteoporotic fractures.
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Objective To analyze the changes of Survivin,MSH6 and MSH2 expression in colorectal cancer and explore their relationship with clinical and pathological parameters.Methods 197 cases of colorectal adenocarcinoma and 20 cases of inflammatory intestinal mucosa were detected by immunohistochemistry with Survivin,MSH6 and MSH2,and the correlation between Survivin,MSH6 and MSH2 expression was analyzed.Results In the control group of 20 cases with inflammatory non-tumor intestinal mucosa,the positive expression rate of MSH2,MSH6,Survivin were 95％,95％,10％,respectively.While the positive expression rate of MSH2,MSH6,Survivin were 88.3％,74.1％ and 84.3％ in 197 cases of colorectal cancer.Survivin positive expression rate in colorectal cancer group was significantly higher than that in inflammatory control group (P ＜ 0.05).Survivin expression was correlated with invasion depth and lymph node metastasis in colorectal cancer tissue (P ＜ 0.05),but not with gender,age,tumor size,gross type or degree of differentiation (P ＞ 0.05).MSH2 expression was correlated with tumor size and lymph node metastasis (P ＜ 0.05),but not with gender,age,gross type,depth of infiltration and degree of differentiation (P ＞ 0.05).MSH6 expression was related to gender and lymph node metastasis (P ＜ 0.05),but not to age,tumor size,gross type,infiltration depth and differentiation (P ＞ 0.05).Colorectal cancer tissues showed positive correlation between MSH6 and MSH2 (r =0.326,P ＜ 0.01),positive correlation between MSH2 and Survivin positive expression (r =0.277,P ＜ 0.01),and positive correlation between MSH6 and Survivin positive expression (r =0.435,P ＜ 0.01).Conclusions The positive expression rate of Survivin in colorectal cancer is high.MSH2,MSH6 and Survivin in colorectal cancer play an important role in the development and progression of colorectal cancer,and can provide evidence for the detection of these three factors,including metastasis risk,prognosis assessment and clinical treatment.In particular,Survivin gene may provide evidence for gene therapy.
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Chinese dry eye consensus 2020 updated the definition and classification of dry eye, stressing tear-film instability as the core mechanism of dry eye.The classification criteria are complemented with tear component abnormality as an important category.As a P2Y 2 receptor agonist, diquafosal sodium is a novel pharmaceutical agent for dry eye treatment.Diquaphosol sodium eye drops can promote the secretion of mucin, fluid and lipid, improve the composition of each layer of tear film, and comprehensively improve the stability of tear film.It also has the function of repairing corneal epithelium, so it can be used to treat ocular surface injury caused by dry eye.Targeting at the inflammation involved in the pathogenesis of dry eye, it can inhibit the inflammatory pathways and the expression of inflammatory factors.The advantages and effectiveness of diquaphosol sodium eye drops in the treatment of dry eye have been demonstrated in multi-center clinical trials, and the Chinese dry eye consensus 2020 has identified diquaphosol sodium eye drops as the first-line treatment for fluid deficient dry eyes and one of the first choices in the treatment of mucin-deficient dry eyes.In this paper, the mechanism, clinical efficacy and safety of diquaphosol sodium in different types of dry eyes, the treatment of different abnormal tear film components and the application of diquaphosol sodium in the Chinese dry eye consensus 2020 were reviewed, so as to deepen its new progress in the treatment of dry eye.
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Objective To explore mediating effect of coping style on the relationship between self-esteem and negative emotions among college students with left-behind experience. Methods The investiga-tion was carried out among 663 college students with left-behind experience by multistage sampling method, using coping style scale, self-esteem scale, self-rating anxiety scale and Beck depression inventory. Re-sults Scores of all scales were shown as follows: self-esteem (3. 09±0. 51),anxiety (34. 94±7. 90),de-pression (8. 80±8. 72),solving problem coping (9. 03±2. 57),help-seeking coping (5. 70±2. 24),self-bla-ming coping (3. 54±2. 24),fantasy coping (4. 56±2. 35),avoidance coping (4. 74±2. 02),rationalizing coping (4. 67±2. 32). Anxiety and depression had significantly negative correlations with self-esteem(r=-0. 46,-0. 50,P<0. 01) ,solving problem coping( r=-0. 29,-0. 30,P<0. 01) and help-seeking coping( r=-0. 08,-0. 18,P<0. 01) ,and significantly positive correlations with rationalizing coping( r=0. 32,0. 28,P<0. 01),self-blaming coping(r=0. 45,0. 43,P<0. 01),fantasy coping(r=0. 33,0. 23,P<0. 01) and avoid-ance coping(r=0. 26,0. 23,P<0. 01). There were partially significant mediating effects of solving problem coping(-0. 09,95％CI:-0. 06--0. 13),rationalizing coping(-0. 03,95％CI:-0. 01--0. 05),self-blaming coping(-0. 11,95％CI:-0. 06--0. 15) ,fantasy coping(-0. 02,95％CI:-0. 01--0. 04) ,and non-significant effects of help-seeking coping and avoidance coping in the relationship between self-esteem and negative e-motions. Conclusion Solving problem coping,rationalizing coping,self-blaming coping and fantasy coping play a partial mediating role in the relationship between self-esteem and negative emotions,while the media-ting effect of help-seeking coping and avoidance coping are not significant.
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The expression levels of serum tenascin-C, osteopontin(OPN), and transforming growth factor-β1(TGF-β1) in the patients of diabetic mellitus were measured by ELISA. With the increase of the UACR, the expression of tenascin-C, osteopontin, and transforming growth factor-β1 showed a trend of increase and hypertension will argument this phenomenon. Pearson correlation analysis showed that levels of tenascin-C were positively correlated with HbA1C , body mass index, systolic blood pressure, diastolic blood pressure, UACR, osteopontin, and transforming growth factor-β1.
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Objective To investigate the risk factors and appropriate screening methods for diabetic peripheral neuropathy (DPN ). Methods This research is a multicenter ,randomized ,cross-sectional study. Questionnaires ,physical examinations and laboratory tests were performed on 1054 elderly diabetic outpatients at 13 hospitals in urban and rural areas of Beijing. Patients were screened for DPN with the five physical examinations recommended by the Diabetes Branch of the Chinese Medical Association. They were divided into a confirmed DPN group(n=449 ,42.6％ ) ,a suspected DPN group(n=276 ,26.2％ ) ,and a non-DPN group(n=329 ,31.2％ ).Multivariate logistic regression was used to analyze risk factors for DPN.The sensitivity ,specificity ,Youden index ,and area under the receiver operating characteristic (ROC)curve were calculated and used for evaluating each test and their combinations in screening DPN and for choosing the opitmal test combination. Results The differences in age ,family income ,duration of diabetes ,glycated hemoglobin(HbA1c) ,hypoglycemia ,and dyslipidemia among three groups were statistically significant (all P<0.01). The decision whether or not to initiate metformin therapy ,metformin doses and DPN prevalence in patients on long-term metformin therapy showed statistically significant differences among three groups (all P<0.01). The differences in the prevalences of cerebral infarction ,diabetic retinopathy ,and peripheral vascular disease among three groups were statistically significant (all P< 0.05).Multivariate Logistic regression analysis suggested that levels of HbA1c ,hypoglycemia ,LDL cholesterol ,whether or not metformin use , metformin dose ,and duration of metformin use were risk factors for DPN in elderly diabetics (all P<0.05) . The combined methods of ankle reflex ,vibratory sensation and temperature sensation used for screening DPN showed the best results with a sensitivity of 94.1％ ,specificity of 75.3％ ,an area under the ROC curve of 0.847 ,and a Yoden index of 0.6945. Conclusions The prevalence of DPN in elderly diabetic outpatients at third-level referral hospitals in Beijing is high. Poor glycaemic control ,repeated episodes of hypoglycemia , metformin use and its daily dose and duration are risk factors for DPN in elderly diabetics.We should focus on strengthening the DPN screening and management of high-risk population.Symptoms of peripheral neuropathy plus ankle reflex ,vibratory and temperature sensations are simple ,rapid and reliable DPN-screening methods ,and can be promoted in outpatient department and primary hospitals.
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Parkinson's disease is an incurable disease, the various therapeutic methods can not completely prevent the development of the disease, and the early treatment can achieve the effect of delaying the progress of this disease. The etiology and pathogenesis of the disease are explained by the theory of collateral disease, and the drug therapy of traditional Chinese medicine (TCM) guided by the theory may obtain satisfactory clinical therapeutic effect. The theory is a continuously deepening process to diagnose a disease from syndrome differentiation-disease differentiation-syndrome differentiation, being consistent with the fundamental thought of TCM.
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<p><b>OBJECTIVE</b>To correlate morphological features with mutations of epidermal growth factor receptor (EGFR) in lung adenocarcinomas.</p><p><b>METHODS</b>According to 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society International Multidisciplinary Lung Adenocarcinoma Classification, a total of 72 surgically resected lung adenocarcinomas were collected and classified into different histological subtypes and different cell types (hobnail, columnar and polygonal). EGFR gene mutation was detected with the amplification refractory mutation method provided by the EGFR mutation test kit. The correlation between these subtypes and EGFR mutations were evaluated.</p><p><b>RESULTS</b>Mutations of EGFR were detected in 48.6% (35/72) of lung adenocarcinomas; 19del and L858R were major mutational types (88.6%, 31/35). EGFR mutations were associated with female gender, non-smoking status, and well to moderately differentiated tumor histology. EGFR mutation types were not associated with age, smoking index, lymph node metastasis, stage, status of whether have or not have inclusion bodies or psammoma bodies and mitotic level. Correlations were observed between acinar and papillary adenocarcinoma subtypes and EGFR mutations according to the new classification. EGFR mutation was rare in the subtype of solid adenocarcinoma with mucin production and almost never observed in special subtypes (mainly mucinous and colloid adenocarcinoma). In addition, EGFR mutation was associated with the hobnail cell type.</p><p><b>CONCLUSION</b>Lung adenocarcinomas of predominate acinar and papillary histological subtypes with hobnail cell morphology are good predictors for EGFR mutations.</p>
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Femenino , Humanos , Masculino , Adenocarcinoma , Genética , Patología , Adenocarcinoma Mucinoso , Genética , Patología , Adenocarcinoma Papilar , Genética , Patología , Genes erbB-1 , Neoplasias Pulmonares , Genética , Patología , Metástasis Linfática , Mutación , Receptores ErbB , Genética , Factores Sexuales , FumarRESUMEN
Objective To observe the efficacy and side effects of combined therapy with victoria A acid,arsenic trioxide and chemotherapeutics for newly diagnosed acute promyelocytic leukemia (APL). Methods 40 cases of patients were treated with combined therapy of ATRA, As2O3 and chemotherapy. The efficacy and side effects were analysed. Results 92.5 % (37/40) achieved complete remission(CR). The CR time was 27(22-61) d by average; leukocytes≥ 10×109/L group complete remission was 72.7 % (8/11), leukocytes < 10×l09/L group complete remission was 100 % (29/29). There was a significant different (x2 =8.550, P =0.004). No severe side effects was observed except one who developed retinoic acid syndrom. Conclusion The combined regimen of ATRA and As2O3 with chemotherapy for acute promyelocytic leukemia should be the first choice management.
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Objective To select an optimal non-specific antigen blocking method by using immuno-infiltration assay so as to suit protein chip preparation. Methods Human papillomavirus type 16 L1 protein expressed by insect-baculovirus espressin system was incubated with skimmed milk powder, calf serum, bovine serum albumin (BSA) combinations of five kinds of methods to block the non-specific antigen. PBS was used as control. The effect of eliminating non-specific stain was detected by immuno-infiltration assay. Results After repeated tests, the results showed that the stability and repeatability of blocking effects were poor for the fixing up antigen first and then blocking method, and the blank control was prone to false positive. The infiltration rate of NC membrane would be affected by using skimmed milk powder as a blocking agent because the pore of NC membrane was easily plugged by milk powder particles. The use of calf serum as a blocking agent made it very difficult to determine the result because the calf serum absorbed by NC membrane produced the background; however, when 20g/L BSA was used to blocking before fixing up antibody, the results became satisfactory. Conclusion Fixing up antibody after blocking in immuno-infiltration assay showed that the blocking effect against non-specific antigen was satisfactory, stable and repeatable, indicating this method is a novel optimal blocking method compared with others.
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Objective To assess the efficacy and safety of intensive pulse light (IPL) device for facial rejuvenation and the treatment of hyperpigmented lesions, facial telangiectasias, acne vulgaris and hair removal. Methods One hundred females who claim to improve their skin texture, hair re-moval and patients with hyperpigmented lesions, facial telangiectasias and acne vulgaris were treated with IPL device. Patients received five treatments with the time interval of 3 weeks to 1 month. Pho-tographs were assessed 1 month after the last treatment. Results For facial skin texture, the total im-provement were scored 100 %. For hyperpigmented lesions and facial telangiectasias, the total im-provement reached to 90%. For ache vulgaris, the total improvement reached to 75 %. For hair re-moval, the total improvement was 95 %. Conclusion The IPL device is an effective and safe modality for the improvement of skin texture, hyperpigmented lesions, facial telangiectasias and hair removal, and a novel modality for the treatment of acne vulgaris.
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Objective To construct eukaryotic expression vector of HPV18 L1- E6, E7 chimeric gene and examine the humoral and cellular immune responses induced by this DNA vaccines in mice. Methods The C-terminal of major capsid protein L1 gene and mutant zinc finger domains of early E6/7 oncogenes in HPV18 were integrated and inserted into eukaryotic expression vector pVAX1 to generate vaccines pVAX1-L1E6Mxx, E7Mxx. CHO cells were transiently transfected with the individual construct. Target protein expressions in the lysate of the transfected cells were measured by ELISA and immunocytochemistry. After BALB/c mice were vaccinated with various recombinant plasmids(pVAX1-L1-E6M3 or pVAX1-L1-E7M3) and immunie adjuvants (pLXHDmB7-2 or LTB) through different administration routes (intramuscular or intranasal) , the great cellular immune responses were produced as revealed by delayed-type hypersensitivity (DTH) and lymphocyte proliferation, and the expression of IL-4 and IFN- γ cells in CD4+ and CD8+subpopulations. Results The highly efficient expression of pVAX1-L1E6Mxx, E7Mxx vector in host eukaryotic cells were demonstrated both by ELISA and immunocytochemistry. The level of specific serum IgG against HPV in experiment groups mice was much higher than that of control group, and intranuscular immunization group had the highest antibody level. Intramuscular immunization groups were superior to intranasal immunization groups in DTH response, splenocyte proliferation and CD8+ IFN-γ + cells number, but CD4+ IL4+ cell number was higher in intranasal immunization groups. The immunization groups using pLXHDmB7-2 as adjuvant were superior to other groups in immunoresponse. Conclusion These DNA vaccines produce remarkable cellular and humoral immuneresponses in the mouse and may provide as prophylatic and therapeutic candidates for HPV induced cancer treatment.
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Objective To investigate the effect of surgical treatment of mammary duct fistula.Methods A total of 48 cases of mammary duct fistula were surgically treated,including 39 cases of fistulectomy and partial mastectomy,4 cases of total mastectomy,3 cases of subcutaneous mastectomy,and 2 cases of papillectomy.The incision was primarily sutured in 33 cases and kept open for drainage in 15 cases.Results A follow-up was carried out in the 48 cases for 3 months ~ 8 years(mean,3 years).Out of the 33 cases of primary closure of wound,5 cases developed a recurrence and then were cured by drainage and regular dressing change.The remaining 43 cases were cured on one session. Conclusions Fistulectomy is the basis of the treatment of mammary duct fistula.For a good cosmetic appearance and a short hospital stay,the operation should be performed with primary closure of wound,unless the recurrence is more likely to happen.
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Objective: To observe the clinical effect of Sangjiao Decoction on treatment of type 2diabetes.Methods: 103 cases of type 2 diabetes patients were divided into two groups at random.In test group,52 cases were given conventional western medical hypoglycemic treatment,alimentary control combined with Sangjiao Decoction.In control group,51 cases were given conventional western medical hypoglycemic treatment and alimentary control.The courses of treatment were both 30 days.Results: Sangjiao Decoction can improve clinical symptoms of type 2 diabetes markedly,the total effective rate of test group and control group was 63.46% and 19.61% respectively.Conclusion: Songjiao Decoction has good synergistic results in reduction of blood glucose and treatment of type 2 diabetes.
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Objective Attenuated strains of Shigella are attractive live vaccine candidates for eliciting mucosal immune responses which is a suitable carrier for the prophylactic human papillomaviruses (HPV) vaccine development, To examine the potential of a live Shigella based prophylactic HPV vaccine, HPV16L1should be expressed in attenuated shigella strain. Methods A Shigella large invasive plasmid (icsA/virG) based prokaryotic expression plasmid pHS3199 was constructed. HPV16L1 gene was inserted into plasmid pHS3199 to form pHS3199-HPV16 L1 construct, and pHS3199-hpv16L1 was electroporated into a live attenuated shigella strain sh42. The expression of HPV16L1 protein was demonstrated by Western blotting with monoclonal antibody to HPV16L1, The genetic stability of recombinant strain sh42-HPV16 L1 was monitored by consecutive passage culture. Invasive ability of sh42-HPV16L1 was evaluated by Hela cell infection assay. Results HPV16 L1 protein can be expressed in recombinant strain sh42-HPV16 L1, and the protein stably expressed over 140 generations. The invasive ability of sh42-HPV16L1 was diminished dramatically compared to its parent strain, but not abolished completely. Conclusion HPV16L1 protein was constitutively expressed in the attenuated strain of shigella flexneri sh42, and maintained partial invasive ability. Our strategy may represent a promising vaccine candidate against genital HPV16 infection.
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To prepare carboxyl terminus truncated human papillomavirus type 58 L1 (HPV58L1) protein and evaluate its ability to form virus-like particles, the baculovirus and Sf-9 insect cells was used to express HPV58L1 protein, and pFastBac-Htb containing HPV58L1 gene sequence of carboxyl terminus truncation was generated. Then Sf-9 cells were infected with recombinant baculovirus. After being cultured, the post-infected cells expressing--HPV58L1 protein were harvested and analyzed by SDS-PAGE and Western blot. The ProBond purification system was used for protein purification. The bio-activity of purified protein was identified by mouse erythrocyte hemagglutination assay, and the VLP formation was examined with transmission electron microscope. Our results showed that the recombinant baculovirus was generated and the Sf-9 cells was infected with the recombinant baculovirus, and after collecting, total cellular proteins were extracted. Truncated HPV58L1 protein with MW 58KD was revealed by SDS-PAGE and confirmed by Western blot. The purified L1 proteins under native condition could cause mouse erythrocytes to agglutinate and form VLP. It is concluded that HPV58L1 protein with carboxyl terminus truncation could be efficiently expressed. In baculovirus Sf-9 cells expression system, the purified protein could self-assemble into virions in vitro, and induce agglutination of mouse erythrocytes, indicating that carboxyl terminus truncation does not interfere with the bioactivity of HPV58L1 protein.
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Humanos , Baculoviridae , Genética , Metabolismo , Proteínas de la Cápside , Dióxido de Carbono , Cuerpos de Inclusión Viral , Proteínas Oncogénicas Virales , Genética , Alergia e Inmunología , Papillomaviridae , Fisiología , Proteínas Recombinantes , Virión , Fisiología , Ensamble de VirusRESUMEN
Objective To eukaryotically exp ress B7.1 extracellular domian and investigate its biological activities. Methods Recombinant expression vector pDisplay/B7.1(V+C) wa s transfected into Hela cells by electroporation method. The expression of B7.1( V+C) was identified by immunohistochemistry and in situ hybridization, respectiv ely. In vitro T lymphocyte activation activity was detected by 3H-TdR incoporation method and the aroused cytotoxicity after mixed culture of pDispla y/B7.1(V+C) transfected Hela cell-T cell was observed by MTT method. R esults B7.1(V+C) was expressed successfully on the surface of Hela c ells. The expressed B7.1(V+C) was able to activate T lymphocytes in the pres ence of anti-CD3 monoclonal antibody. Cytotoxicity could be observed when pDisp lay/B7.1(V+C) transfected Hela cells were mixed and co-cultured with T lymphocy tes. Conclusion Eukaryotically expressed B7.1(V+C) main tains its T lymphocyte costimulatory activity, and B7.1(V+C) can be adopted to construct bifunctional molecules for tumor immunotherapy.
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<p><b>OBJECTIVE</b>To develop an efficient expression, purification system of recombinant Escherichia coli heat-labile enterotoxin B subunit (rLTB) and study its activity against mucosal immunoadjuvant by nasal immunization.</p><p><b>METHODS</b>A recombinant, pMMB68-LTB was generated by cloning the LTB cDNA fragment into an expression vector (pMMB68) and transformed it into the host strain marine vibrio VSP60. The relevant target protein was identified using SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. Sephacryl S-100 gel filtration chromatography was carried out for purification of rLTB in engineering bacteria VSP60. BALB/c mice received hen egg lysozyme (HEL) alone or combined with rLTB by nasal administration. After three times immunization, IgG and IgA antibody levels in serum or small intestine wash samples were determined using ELISA.</p><p><b>RESULTS</b>rLTB protein was highly expressed in VSP60. After gel filtration with Sephacryl S-100, the purity of rLTB reached 98.1%, the yield rate was about 52%. After immunization, IgG and IgA antibody responses specific to HEL in system and mucosa of HEL + rLTB groups were significantly increased, compared with the HEL alone group (P < 0.001).</p><p><b>CONCLUSIONS</b>A set of protocols for large-scale rLTB preparation has been established, which is simple, efficient and applicable. The rLTB protein we prepared was proved to be a powerful mucocal adjuvant, which could greatly enhance systemic and mucosal immune responses to nasally co-administered antigen.</p>