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 20g/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.

This study aimed to investigate the effects of concentration, intestinal section and borneol on the intestinal absorption of salvianolic acids. The experiment not only studied the intestinal absorption properties of three concentrations of rosmarinic acid, salvianolic acid B and salvianolic acid A at duodenum, jejunum and ileum, but also of salvianolic acids compatible with borneol at different concentrations using single-pass intestinal perfusion model in rat with phenol red as the marker. The results showed that salvianolic acids was stable under weak-acid condition and affected by metabolism enzyme; The Peff and Ka significantly different among three concentrations of rosmarinic acid and salvianolic acid B, whose intestinal absorption were saturated in high concentration, suggesting that the transport mechanisms of rosmarinic acid and salvianolic acid B were similar to active transport or facilitated diffusion; However, there was inconspicuousness in the Peff and Ka of salvianolic acid A at different concentrations, whose absorption was not saturated in high concentration, indicating that the transport mechanisms of salvianolic acid A was passive diffusion; The Peff and Ka in the ileum obviously higher than those in the duodenum and jejunum, namely the ileum was the best absorption section; When concentration of borneol increased, the enhancing effect of intestinal absorption of salvianolic acids increased, but significantly decreased when borneol increased to some degree. The enhancing effect of medium borneol concentration was the optimum. This implied that borneol can enhance the intestinal absorption of salvianolic acids, and the capacity of enhancing effect was influenced by the concentration of borneol.

Objective To construct the human interleukin-18(hIL-18) DNA plasmids vaccine and to express the eukaryotic plasmids vaccine in mammalian cell lines Cos-7 and D5.Methods Gene recombinant technique was used to construct hIL-18 eukaryotic expression vectors.Calcium phosphate method was performed to transect recombinant hIL-18 eukaryotic expression vectors into Cos-7 and D5 cells.In situ hybridization and Western Blot were implemented to verify the transient expression of recombinant hIL-18 in Cos-7 and D5.Results The eukaryotic expression plasmid pVAX1-IL 18 was constructed successfully.hIL-18 was transiently expressed in Cos-7 and D5.Conclusion The eukaryotic expression plasmid pVAX1-IL 18 was constructed.In situ hybridization and Western Blot results proved the successful transient expression of pVAX1-IL 18 in Cos-7 and D5.Therefore,the work has settled the foundation for further biological research on hIL-18,including immunogene therapy through hIL-18.

Objective To express human B7.2 extracellular domain with prokaryote expression system and to evaluate its biological activity in vitro. Methods PCR was used to amplify the extracellular region of human B7. 2which contained both the IgV and IgC domains. The recombinant PGEX-4T-3/hB7. 2 (IgV+C) was obtained by cloning the PCR product into a prokaryote expression plasmid PGEX-4T-3 and was transformed into the host strain of DH5-α. The fusion protein consisted of GST and hB7.2(IgV+C) was identified by SDS-PAGE and Western blotting.T cell activation was observed by exposing purified T lymphocytes to the fusion protein and [3H]-TdR incorporation with the presence of the first signal imitated by anti-CD3 antibody. Results The fusion protein GST-hB7.2 (IgV+C) was produced and detected in inclusive body form from engineered bacterial cells. With the first signal existed,T lymphocytes proliferated when it was co-stimulated by the fusion protein. Conclusion These results indicated that the functional human B7.2(IgV+C) fusion protein can be produced in bacterial cells and the fusion protein displays the co-stimulatory activity in T lymphocytes activation.

Objective To analyze mRNA expressions of 7 cytoklnes which influence the immune response in lym- phocytes in pleural effusion of non-small cell lung cancer patients to evaluate the effect of local tumor microenviron- ment on anti-tumor immune response and to explore the mechanism of tumor escape. Methods Detecting the mRNA expression of IL-2,INF-γ,IL-12,IL-18,IL-10,IL-4 and TGF-β 1 in lymphocytes in pleural effusion of non-small cell lung cancer patients and tuberculotic pleurisy patients on the single cell level by using in situ hybridization. Results In the pleural effusion of non-small cell lung cancer, the mRNA expressions of IL-10,TGF-β1 and IL-4 were signifi- cantly higher than those of IL-2,IL-12,IL-18 and INF-γ,as well as these of control group. The cytokine expression levels of tuberculotic pleurisy patients were very Iow, and there were no significant differences between different cy- tokines. Conclusion Type 2 cytokines are expressed predominantly in the pleural effusion of non-small cell lung can- cer. The increased co-expression of IL-10 and TGF-β1 indicates that they might act Jointly and play a critical role in the immunosuppression of non-small cell lung cancer.

Objective To investigate the role of heparin binding epidermal growth factor-like growth factor(HB-EGF)in active psoriasis vulgaris.Methods HB-EGF mRNA and protein were detected by hy-bridization in situ and immunohistochemistry in normal skin tissues,lesional and non-lesional psoriatic skin of progressive stage.Results In normal skin tissues,the stain of HB-EGF mRNA and protein was located in the basal layer of epidermis(100.00%)and there was only a little expression in the suprabasal layers(16.67%).Focal overexpression was found in the suprabasal layers of non-lesional and peri-lesional psoriat-ic skin(88.00%,80.00%respectively);however,there was no HB-EGF mRNA protein expression in the superabasal layers of the central part of psoriatic lesions(0),and nearly no expression in the basal layer(4.00%).Conclusion HB-EGF may play an important role in the pathogenesis of early psoriasis.

OBJECTIVETo investigate which of the two immunoglobulin (Ig)-like domains, the immunoglobulin variable region homologous domain IgV (hB7.2 IgV) and the immunoglobulin constant region homologous domain IgC (hB7.2 IgC) on the human B7.2 molecule contains receptor binding sites, and to evaluate whether the B7.2 protein expressed in bacteria has biological activity in vitro.

METHODSThree fragments of hB7.2 IgV,hB7.2 IgC and the complete extracellular region of human B7.2 containing both the IgV and IgC domains,hB7.2 Ig (V+C), were amplified by PCR and subcloned into pGEM-Teasy. Three recombinants,pGEX-4T-3-hB7.2 IgV,pGEX-4T-3-hB7.2 IgC and pGEX-4T-3-hB7.2 Ig (V+C), were generated by cloning the fragments into a prokaryote expression plasmid (pGEX-4T-3) and transformed into the host strain E. coli DH5alpha. The relevant target fusion proteins consisting of GST and hB7.2 IgV,hB7.2 IgC and hB7.2 Ig (V+C), were identified by SDS-PAGE and Western blotting. With the presence of the first signal imitated by anti-CD3 antibody, T cell activation was observed by exposing purified T lymphocytes to each soluble form of the three bacterially-produced human B7.2 fusion proteins by [(3)H]-TdR incorporation.

RESULTSThree recombinant fusion proteins of human B7.2, GST-hB7.2 IgV, GST-hB7.2 IgC and GST-hB7.2 Ig (V+C) were produced and detected in inclusion body form from engineered bacteria. With the first signal present,T lymphocytes proliferated when co-stimulated by bacterially-produced either GST-hB7.2 Ig (V+C) or GST-hB7.2 IgV fusion proteins, but not by GST-hB7.2 IgC.

CONCLUSIONSFunctional human B7.2 fusion protein can be produced in bacteria. The IgV-like domain of human B7.2 is sufficient for B7.2 to interact with its counter-receptors and co-stimulate T lymphocytes.

Antigens, CD ; pharmacology ; B7-2 Antigen ; Escherichia coli ; genetics ; Humans ; Immunoglobulin Constant Regions ; pharmacology ; Immunoglobulin Variable Region ; pharmacology ; Lymphocyte Activation ; Membrane Glycoproteins ; pharmacology ; Plasmids ; Recombinant Fusion Proteins ; pharmacology ; T-Lymphocytes ; immunology

OBJECTIVETo 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.

METHODSA 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.

RESULTSrLTB 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).

CONCLUSIONSA 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.

Adjuvants, Immunologic ; administration & dosage ; pharmacology ; Administration, Intranasal ; Animals ; Bacterial Toxins ; administration & dosage ; isolation & purification ; pharmacology ; Blotting, Western ; Electrophoresis, Polyacrylamide Gel ; Enterotoxins ; administration & dosage ; isolation & purification ; pharmacology ; Escherichia coli ; Escherichia coli Proteins ; Immunization ; Mice ; Mice, Inbred BALB C ; Nasal Mucosa ; immunology ; Recombinant Proteins ; administration & dosage ; isolation & purification ; pharmacology