[Preparation of a polyclonal antibody against human LYZL4 and its expression in the testis].

OBJECTIVE: To prepare a polyclonal antibody against human lysozyme-like protein 4 (LYZL4) expressed in the prokaryotic system and identify the distribution of LYZL4 in the testis. METHODS: The full-length cDNA of LYZL4 was cloned into the pET32a plasmid and the expression of the recombinant LYZL4 (rLYZL4) was induced by IPTG. The rLYZL4 was purified by Ni-NTA and chitin affinity chromatography respectively and its bactericidal activity was observed by bilayer agar plate diffusion assay. The purified rLYZL4 was used as an immunogen to generate the polyclonal antibody, followed by examination of the antibody titer by ELISA and its specificity by Western blot. The distribution of LYZL4 in human tissue, sperm and seminal plasma was identified and its subcellular localization in the testis was determined by immunohistochemistry. RESULTS: rLYZL4 was expressed efficiently in the prokaryotic system and exhibited no bacteriolytic activity against M. lysodeikticus and E. coli. The anti-rLYZL4 polyclonal antibody could bind the recombinant protein with a high sensitivity and specificity. LYZL4 was identified in the testis, epididymis and sperm protein extracts and localized in the acrosomal region of round and elongating spermatids. CONCLUSIONS: An anti-rLYZL4 polyclonal antibody was successfully prepared using the prokaryotic expression system. LYZL4 was detected in the acrosomal region of round and elongating spermatids, suggesting an association with the structure and function of the acrosome.

[Expression of human lysozyme-like protein 6 in the male reproductive system].

OBJECTIVE: To study the expression of human lysozyme-like protein 6 (LYZL6) in the male reproductive system and its physiological role. METHODS: The recombinant P. pastoris strain was cultured and induced with methanol to express LYZL6, followed by purification using chitin affinity chromatography. The bactericidal activity of the recombinant LYZL6 was observed by bilayer agar plate diffusion assay, and then the recombinant protein was used as an immunogen to generate polyclonal antibodies, whose specificity was examined by ELISA. The distribution of LYZL6 in the human tissue and semen was identified by Western blotting and the subcellular localization in the testis was investigated by immunohistochemistry. RESULTS: At pH 5.6, recombinant LYZL6 exhibited a high bacteriolytic activity against M. lysodeikticus. ELISA analysis showed that the anti-LYZL6 polyclonal antibodies could bind the recombinant protein with a high specificity. Western blot manifested the expression of LYZL6 in the testis and epididymis, higher in the former than in the latter. LYZL6 was also detected in the sperm protein extract, while protein bands were not observed in the seminal plasma. Immunodetection with a specific antiserum localized the LYZL6 protein in the late spermatocytes and round spermatids. CONCLUSIONS: LYZL6 has a higher bacteriolytic activity under low pH condition and is bound to spermatozoa after secreted in the testicular epithelia, suggesting that LYZL6 could act as a potential hydrolase for carbohydrates in zona pellucida penetration.

Comparative evaluation of immunization with recombinant protein and plasmid DNA vaccines of fusion antigen ROP2 and SAG1 from Toxoplasma gondii in mice: cellular and humoral immune responses.

The aim of this work was to evaluate immune responses in BALB/c mice vaccinated subcutaneously by recombinant protein, or intramuscularly by plasmid DNA with fusion antigen of rhoptry protein 2 (ROP2) and major surface protein 1 (SAG1) from Toxoplasma gondii (T. gondii). BALB/c mice were immunized with one of three different antigen formulations respectively, which were rROP2-SAG1, pcROP2-SAG1, and pcROP2-SAG1 boosted with rROP2-SAG1. The production of IgG, IgG subclasses, lymphoproliferation, and level of gamma interferon (IFN-γ) were detected after vaccination. The animals vaccinated with rROP2-SAG1 quickly developed specific anti-TLA (T. gondii lysate antigen) antibodies, which continued to rise after immunization. However, production of IgG against TLA in mice vaccinated with pcROP2-SAG1 was relatively slow and maintained a high level after reaching plateau. There are more vigorous specific lymphoproliferative responses observed in mice of group rROP2-SAG1 than in pcROP2-SAG1. Immune responses in mice of group pcROP2-SAG1 boosted with rROP2-SAG1 were similar to the protein immunization group. Three immunization procedures resulted in a similar level of IFN-γ production. Our results indicate that BALB/c mice vaccinated by three immunization procedures induce similar humoral and cellular immunity against infection of T. gondii. Mice immunized with recombinant protein rROP2-SAG1 produce more humoral immune responses than mice immunized with other antigen formulations.

Characterization and expression of HLysG2, a basic goose-type lysozyme from the human eye and testis.

Lysozyme plays an important role in human innate immunity by causing bacterial cell lysis. We describe for the first time, the actual performance of human lysozyme g-like 2 (HLysG2), a mammalian g-type lysozyme. RT-PCR revealed that the HLysG2 gene was transcribed in eye and testis tissues. A spot was detected from human tears using 2D gel electrophoresis and was identified as HLysG2 using MALDI-TOF/TOF MS and a MASCOT search with a matching score of 140 and 27% sequence coverage of the whole amino acid sequence. To gain insight into the in vitro antimicrobial activities of HLysG2, the mature peptide-coding region was cloned into Pichia pastoris for heterogeneous expression. Recombinant HLysG2, had an optimal at pH 6.0 and 30 °C, reached the peak activity of 1.2 × 10(4)U/mg at the sodium ion concentration of 75 mM and showed a higher salt tolerance than human c-type lysozyme (HLysC). Recombinant HlysG2 inhibited Gram-positive bacterial growth and did not inhibit Gram-negative bacterial and Candida albicans growth. Results indicated that HLysG2 is a potent antibacterial protein that may play a role in the innate immunity of the human eye.

[Studies on the establishment of a method to detect HPV 6b E7-specific antibodies of serum and cervical secretion from patients with condyloma acuminatum and its epidemiological significance].

OBJECTIVE: To establish a method for detection of the human papi11omavirus (HPV) 6b E7-specific antibodies in serum and cervical secretion from patients with condyloma acuminatum (CA). METHODS: A full-length HPV 6b E7 gene was amplified by PCR from the CA tissue to construct the recombinant plasmid pET32a(+)/HPV 6b E7. The expression of prokaryotic protein was analyzed by SDS-PAGE and Western blot, then purified with Ni-NTA Agarose affinity column and used as an diagnostic antigen for establishing indirect ELISA method, to detect specific serum IgG and specific cervical secretion sIgA from 56 CA patients, 81 healthy control. Sera from 43 cervical cancer was served as control. HPV 6b DNA from 56 CA patients was identified by PCR. RESULTS: Data showed that the nucleotide homology of cloned sequence was 99.5%, compared to the standard sequences of HPV 6b E7 gene (GenBank accession number: NC001355). A high level expression of E7 fusion protein was obtained in prokaryotic expression system (40 µg/ml). Based on HPV 6b E7 fusion protein being used as coating antigen, results from ELISA showed that the absorbance rates (A) of serum IgG from CA, cervix cancer and healthy control groups were 1.82 ± 0.48, 1.36 ± 0.39 and 1.39 ± 0.27, respectively. The level of IgG antibody in the serum of CA group was significantly higher than that in cervix cancer group and healthy control (P < 0.05). The A values of cervical secretion sIgA in CA and healthy control groups were 0.63 ± 0.26 and 0.53 ± 0.06, respectively, while the level of sIgA antibody in the cervical secretion of CA group was also significantly higher than that in healthy controls (P < 0.05). The positive rate of HPV 6b E7 DNA in CA tissue was 78.6% (44/56) by PCR method. When compared the results measured by PCR, the HPV 6b E7-specific IgG and sIgA antibodies by ELISA used to detect the patients infected with HPV 6b infection, showed that the sensitivity rates were 68.2% (30/44) and 54.6% (24/44) respectively, and the specificity were all 100% (12/12). CONCLUSION: Based on the serum and cervical secretion specific HPV 6b E7 antibodies from patients with CA to diagnose HPV 6b infection, results showed medium sensitivity and high specificity, and could further be used to investigate the epidemiological characteristics of HPV 6b infection.

[Immune response elicited by the recombinant protein and plasmid DNA of complex antigen ROP2-SAG1 from Toxoplasma gondii].

OBJECTIVE: To study the immune response elicited by the recombinant protein vaccine and DNA vaccine of the complex antigen ROP2-SAG1 from Toxoplasma gondii. METHODS: Sixty female BALB/c mice were randomly divided into 4 groups (15 per group). Mice in rROP2-SAGI group were immunized subcutaneously with 2.5 microg rROP2-SAG1 protein formulated in Freund's adjuvant. Mice in control group received only adjuvant emulsified with normal saline. Mice in recombinant plasmid pcROP2-SAG1 and control plasmid pcDNA3.1 groups were each injected intramuscularly with 100 microg of pcROP2-SAG1 and pcDNA3.1, respectively. All the mice received three immunizations at 2-week intervals. Serum samples were collected at 25, 45, and 70 days after immunization for determining antibody IgG, and at 2 weeks after the last immunization IgG1 and IgG2a were detected all by ELISA. Cell counting kit-8 (CCK-8) was used to determine the splenocyte proliferation, and the supernatant of cultured splenocytes was collected for the detection of IFN-gamma by ELISA. RESULTS: The level of IgG continued to rise in rROP2-SAG1 group after immunization, and similarly in pcROP2-SAG1 group. At 2 weeks after the last immunization, level of IgG1 (1.538 +/- 0.183) was higher than that of IgG2a (0.618 +/- 0.122) (P < 0.05) in rROP2-SAG1 group. Whereas no significant difference between IgG1 (1.107 +/- 0.137) and IgG2a (0.830 +/- 0.185) was observed in pcROP2-SAG1 group (P > 0.05). Compared with the pcROP2-SAG1 group (A450 = 0.123 +/- 0.018), more significant proliferation response of splenocytes was observed in rROP2-SAG1 group (0.348 +/- 0.042) (P < 0.05). There was no significant difference (P > 0.05) of IFN-gamma and IL-2 in the supematant of cultured splenocytes between the groups of rROP2-SAG1 and pcROP2-SAG1. CONCLUSION: The antibody level and splenocyte proliferation have been significantly higher in mice immunized with recombinant protein rROP2-SAG1 than those with recombinant plasmid pcROP2-SAG1.

[Immunogenicity of multi-epitopes gene of major outer membrane protein of Chlamydia trachomatis].

OBJECTIVE: To construct a recombinant eukaryotic expression plasmid pcDNA3.1-Ct MOMP168 including Ct MOMP multi-epitopes gene, and evaluate the Ct MOMP-specific humoral and cellular immune response induced by pcDNA3.1-Ct MOMP168 in BALB/c mice. METHODS: Recombinant plasmid pcDNA3.1-Ct MOMP168 including Ct MOMP multi-epitopes gene was constructed. Then, BALB/c mice were randomly assigned to receive (intramuscular injection) either pcDNA3.1-Ct MOMP168 or pcDNA3.1 or PBS (n = 12, 100 microg/time per mouse), and the same immunization schedule was repeated for the third time at 2 week intervals. The titers of anti-Ct MOMP antibody and its antibody subtypes in sera, the cytotoxicity of Ct MOMP-specific cytotoxic T lymphocyte (CTL) in spleen, and the level of cytokine (IFN-gamma, IL-4, IL-10)-producing CD3(+) T cells in spleen were detected by ELISA, LDH release assays and intracellular cytokine staining-fluorescence activated cell sorter (ICS-FACS), respectively. RESULTS: The recombinant plasmid pcDNA3.1-Ct MOMP168 was able to induce Ct-specific antibody response (A(490) = 0.973 +/- 0.136; serum titer was 1:1000) as compared with pcDNA3.1 (A(490) = 0.180 +/- 0.025) and PBS (A(490) = 0.110 +/- 0.015), and the major antibody subtype was IgG2a with statistical significance (F = 106.884, P < 0.05). When the ratio of effector cells and target cells reached to 50:1, the activity of cytotoxic T-lymphocyte in pcDNA3.1-Ct MOMP168 immunized mice (41.71% +/- 8.34%) was significantly higher (F = 22.315, P < 0.05) than that in pcDNA3.1 immunized mice (18.40% +/- 3.45%) and PBS immunized mice (14.50% +/- 2.42%). The levels of CD3(+) IFN-gamma(+) T cells in pcDNA3.1-Ct MOMP168 immunized mice (1.15% +/- 0.16%) were significantly higher (F = 99.638, P < 0.05) than that in pcDNA3.1 immunized mice (0.12% +/- 0.08%) and PBS immunized mice (0.09% +/- 0.03%), while the significant difference in the levels of IL-4(+) CD3(+) T cells and IL-10(+) CD3(+) T cells was not observed (F = 0.886 and 1.112, P > 0.05) between pcDNA3.1-Ct MOMP168 immunized mice (0.13% +/- 0.08% and 0.14% +/- 0.08%) and pcDNA3.1 (0.07% +/- 0.05% and 0.13% +/- 0.06%) or PBS immunized mice (0.08% +/- 0.04% and 0.07% +/- 0.04%). CONCLUSION: In BALB/c mice, the recombinant plasmid pcDNA3.1-Ct MOMP168 might induce not only the generation of Ct-specific antibody, but also the high level of Ct MOMP-specific CD3(+) IFN-gamma(+) T cells.

[Preparation and identification of immune serum against recombinant fusion protein of rhoptry 2 and major surface protein 1 from Toxoplasma gondii].

OBJECTIVE: To prepare and identify immune serum against the recombinant fusion protein of rhoptry 2 (ROP2) and major surface protein 1(P30) from Toxoplasma gondii. METHODS: The constructed recombinant plasmid of pET28b/ROP2-P30 was transformed to a bacterium BL21-Codon Plus (DE3)-RIL strain and was expressed under IPTG induction. Cells were lysed by multiple rounds of sonication to obtain supernatant and inclusion body respectively. The inclusion body was washed with 2 mol/L and 4 mol/L urea to remove the nonspecific protein. The washed products dissolved in 8 mol/L urea were received by SDS-PAGE. Two rabbits were immunized with the fusion protein rROP2-P30 and sera from the rabbits were collected. Immune diffusion test, indirect ELISA and Western-blot were used to detect antibody titer and specificity of the immune serum against rROP2-P30. RESULTS: Immune diffusion test demonstrated that specific immune serum were obtained. Indirect ELISA confirmed that the antibody titer in the serum reached 1:12 800 and the rROP2-P30 was recognized by specific IgG in this serum by Western-blot analysis. CONCLUSION: Specific immune serum against the recombinant fusion protein rROP2-P30 has been prepared.

[Cometabolic biodegradation of nitrogenous heterocyclic compounds indole and pyridine under anoxic conditions].

Based on the traditional theory of denitrification under anoxic conditions, and with the addition of nitrate, experiments were conducted to investigate the cometabolic biodegradation of nitrogenous heterocyclic compounds-indole and pyridine. Results show that the optimum ratio of COD to nitrate (C/N) is 8.4 to approximately 8.9. Under the conditions with temperature of 28 degrees C and pH of 7.0 to approximately 7.5, the nitrate reductase activity (NRA) is in the best state. Addition of pyridine can promote NRA and the degradation of indole. When the initial concentration of indole is 150 mg/L, the concentration ratio of indole to pyridine is 1 to approximately 10, and under the optimum C/N conditions, the degradation of indole meet with zero-order kinetics. There was no accumulation of nitrite during the reaction. When the concentration ratio of pyridine to indole is less than 0.25, with the increase of pyridine concentration, there is a faster augment rate for NRA and the degradation of indole than the situation when the concentration ratio of pyridine to indole is more than 0.25.

[Evaluation of therapeutic effects of Chinese materia medica by tongue image analysis software 1.0 based on tongue colors].

OBJECTIVE: To evaluate the therapeutic effects of Chinese materia medica in treating patients with different syndromes by tongue image analysis software 1.0 based on tongue colors, and to discuss the feasibility of applying this computer science-based techniques into drug evaluation. METHODS: The tongue colors and the areas of tongue fur were examined and analyzed by the tongue image analysis software 1.0 in healthy persons and the patients with different syndromes before and after treatment. The parameters of tongue colors consisted of the followings: the hue (H), the lightness (L), the saturation (S), and the values of red (R), green (G) and blue (B). RESULTS: Obvious differences could be revealed in tongue color index between the healthy persons and the patients in five groups of different syndromes. There also existed some significant differences in those index between patients before and after treatment. CONCLUSION: The tongue image analysis software 1.0 based on tongue colors is helpful to evaluate the therapeutic effects of Chinese materia medica.

[Cloning and expression of the fused gene of rhoptry protein ROP2 and major surface protein P30 from Toxoplasma gondii].

OBJECTIVE: To clone and express the fused gene fragment coding rhoptry protein ROP2 and major surface protein P30 from Toxoplasma gondii as a preparation for the construction of the complex ROP2-P30 antigen by gene engineering. METHODS: The gene fragment encoding P30 was amplified by PCR from T. gondii RH strain and subcloned into the recombinant plasmid pUC119/ROP2 already constructed. The recombinant plasmid pUC119/ROP2-P30 was digested by Sac I/HindIII and inserted into the same site of expression vector pET28b. The recombinant plasmid of pET28b/ROP2-P30 was transformed to E. coli and expressed under the induction of IPTG. RESULTS: The gene fragment 700 bp encoding P30 was obtained from the total DNA of T. gondii by PCR. The recombinant plasmid pET28b/ROP2-P30 was successfully constructed, which was highly expressed in E. coli, a fusion protein with molecular weight of 69000. CONCLUSION: The fusion gene encoding the rhoptry protein ROP2 and the major surface protein P30 of T. gondii has been successfully cloned and expressed to be an expected recombinant fusion protein ROP2-P30 with molecular weight 69000.

[Clinical pathology and pathogenesis of severe acute respiratory syndrome].

BACKGROUND: To explore the pathological features and pathogenesis of severe acute respiratory syndrome (SARS) to provide evidence for the clinical treatment and prevention of SARS. METHODS: Pathological features of 2 cases of full autopsy and 4 cases of needle biopsy tissue samples from the patients who died from SARS were studied by light and electron microscopy. The distribution and quantity of lymphocyte subpopulations in the lungs and immune organs from SARS patients were analyzed by immunohistochemistry. The location and semi-quantitative analysis of SARS coronavirus in the tissue specimens were studied by electron microscopy, in situ hybridization and immunohistochemistry. RESULTS: In total of 6 cases, diffuse alveolar damage and alveolar cell proliferation were common. The major pathological changes of 2 autopsy cases of SARS in lung tissues were acute pulmonary interstitial and alveolar exudative inflammation, and 2 autopsy and one biopsy lung tissues showed alveolar hyaline membrane formation. Terminal bronchiolar and alveolar desquamation of lung tissues in one autopsy and 2 biopsy cases were noted. Among 6 cases, 2 biopsy cases presented early pulmonary fibrosis and alveolar organization. Meanwhile, the immune organs, including lymph nodes and spleens from 2 autopsy cases of SARS whose disease courses were less than 12 days showed extensive hemorrhagic necrosis, reactive macrophage/histocyte proliferation, with relative depression of mononuclear and granulocytic clones in the bone marrows. However, spleen and bone marrow biopsy tissue samples from 4 dead SARS cases whose clinical course lasted from 21 to 40 days presented repairing changes. SARS coronaviruses were mainly identified in type I and II alveolar epithelia, macrophages, and endothelia; meanwhile, some renal tubular epithelial cells, cardiomyocytes, mucosal and crypt epithelial cells of gastrointestinal tracts, parenchymal cells in adrenal glands, lymphocytes, testicular epithelial cells and Leydig's cells were also detected by electron microscopy combined with in situ hybridization. The semi-quantitative analysis of lymphocyte subpopulations revealed that the proportion of CD8+ T lymphocytes were about 80% of the total infiltrative inflammatory cells in the pulmonary interstitium, with a few CD4+ lymphocytes CD3+, CD4+, CD8+ or CD20+ lymphocyte subpopulations were obviously decreased and there was imbalance in number and proportion, while CD57+, CD68+, S-100+ and HLA-DR+ cells were relatively increased in lymph nodes and spleens. CONCLUSIONS: Histologically, the pulmonary changes could be divided into acute inflammatory exudative, terminal bronchiolar and alveolar desquamative and proliferative repair stages or types during the pathological process of SARS. SARS coronavirus was found in multi-target cells in vivo, which means that SARS coronavirus might cause multi-organ damages which were predominant in lungs. There were varying degrees of decrease and imbalance in number and proportion of lymphocyte subpopulations in the immune organs of the patients with SARS. However, these changes may be reversible. It was found that cellular immune responses were predominant in the lungs of SARS cases, which might play an important role in getting rid of coronaviruses in infected cells and inducing immune mediated injury.

[Cut-off period of subclassification and pathological features of severe hepatitis based on clinical and pathological analyses].

BACKGROUND: To explore the cut-off period of subclassification and pathological features of severe hepatitis (SH). METHODS: Based on combined clinical and pathological analyses, the complete clinical and biopsy or autopsy liver tissues data from 196 cases of patients with severe hepatitis were investigated. Meanwhile, proliferative hepatocytes, cholangioepithelia and collagens were identified by a panel of monoclonal antibodies such as those against albumin, cytokeratin 18,19 and collagen I, III with immunohistochemical method. RESULTS: The clinical and pathological analyses indicated the cut-off periods of acute, subacute and chronic SH (ASH,SSH and CSH) were (13.4+/-7.2) d, (77.4+/-69.3) d and (80.5+/-63.2) d, respectively. Among all SH cases, one case of ASH patient presented clinical manifestation and pathological changes of ASH for 21 days, however, one patient with SSH was demonstrated 12 day course by histological examination. The time of cut-off period between ASH and SSH in child cases was shorter than that in adult cases. Histologically, ASH liver tissues showed massive and/or submassive necrosis caused by one attack, with congestive sinusoid frameworks and proliferative cholangioepithelium-like hepatocytes, while SSH liver tissues presented combined fresh and old submassive or massive necrosis caused by multiple attacks, accompanied by obviously proliferative bile ducts and sinusoid framework collapse.However, the pathological changes of CSH showed ASH- or SSH-like lesions on the background of chronic liver injury. CONCLUSION: Our data indicated that the cut-off period between ASH and SSH is in accordance with the Scheme of Viral Hepatitis Prevention and Therapy, China, published in 2000, but excluded a part of child SH cases. In our study, the authors found a few pathological features in ASH and SSH.