Preparation and activity detection of chicken egg yolk IgY antibody against human papillomavirus 16 type L1 main capsid protein / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare highly specific chicken egg yolk IgY antibody against human papillomavirus 16 type L1 main capsid protein (HPV16L1) for detection of HPV16L1.</p><p><b>METHODS</b>Purified HPV16L1 protein was used to immunize the hens, from which the eggs were collected since one week after the first immunization. The egg yolk was separated and the IgY antibody purified by PEG-6000 method. The bioactivity of the antibody was tested using enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry was performed to detect the HPV16L1 in the CHO cells transfected with the recombinant pcDNA-EGFP-HPV16L1 plasmid (containing EGFP-HPV16L1 fusion gene) for assessing the specific affinity of IgY to HPV16L1.</p><p><b>RESULTS</b>After 3 immunizations of the hens, the titer of the purified IgY antibody against HPV16L1 from the egg yolk reached 1:10240. The IgY bound specifically to the EGFP-HPV16L1 protein expressed in the transfected CHO cells.</p><p><b>CONCLUSION</b>High titer IgY can be prepared by immunization of the hens with HPV16L1 protein, and the prepared IgY can be used for HPV16L1 detection at the cellular level.</p>

Identification of metastasis-associated proteins of ovarian cancer by proteomics / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the differenal protein expression profiles of ovarian tumor cell lines with distinct metastatic abilities.</p><p><b>METHODS</b>The ovarian cancer cell line HO8910 and HO8910pm, derived from same parental cells but exhibited different metastatic ability, were investigated by two-dimensional gel electrophoresis (2-DE)-MALDI-TOF-MS proteomic approach.</p><p><b>RESULTS</b>Thirty-nine proteins were detected by 2-DE to have expression disparity levels over 2 folds between two cell lines. Eighteen of them were identified by MALDI-TOF-MS. The proteins are involved in apoptosis, extra cellular matrix (ECM), cytoskeleton, growth factor, glycolysis, protein metabolism and immune system.</p><p><b>CONCLUSION</b>The data are valuable for the identification of differentially expressed proteins involved in the biological behavior of human ovarian cancer.</p>

Small interfering RNA-mediated MAPK p42 silencing induces apoptosis of HeLa cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of small interfering RNA (siRNA)-induced MAPK p42 silencing on the survival of HeLa cells.</p><p><b>METHODS</b>Two siRNAs targeting at the MAPK p42 gene and one random siRNA were synthesized respectively by Silencer siRNA Construction Kit and transfected into HeLa cells by Lipofectamin 2000. The expression of p42(MAPK) in the transfected HeLa cells was analyzed by Western blotting and immunohistochemistry, and the morphology of cells were observed with electron microscope. TUNEL assay and Annexin V/PI staining were employed for detecting the cell apoptosis.</p><p><b>RESULTS</b>The expression of p42(MAPK) in the HeLa cells was remarkably suppressed after transfection with the two siRNAs, reduced by about 2.5 and 3.2 folds respectively in comparison with the negative control. Chromatin margination in the cell nuclei were observed in the transfected cells, and TUNEL assay and Annexin V/PI staining further confirmed the occurrence of cell apoptosis.</p><p><b>CONCLUSION</b>In vitro MAPK p42 siRNA-1 and siRNA-2 transfection can specifically silence the gene expression and induce apoptosis of HeLa cells.</p>

Inhibition of the expression of p42MAPK in HeLa cell line by RNA interference / 中华病理学杂志

<p><b>OBJECTIVE</b>To screen for siRNAs that inhibit the expression of p42(MAPK) in HeLa cell line.</p><p><b>METHODS</b>Three p42(MAPK) siRNAs and one random siRNA were synthesized using Silencer siRNA Construction Kit, and labeled with Cy-3 for measurement of transfection effect. SiRNAs were transfected into HeLa cells by Lipofectamin 2000. The expression of p42(MAPK) was analyzed by Western blot. The biological effect of siRNAs on HeLa cell growth was monitored by MTT and flow cytometry.</p><p><b>RESULTS</b>Two siRNAs (siRNA-2 and siRNA-3) among three tested were identified to be able to downregulate the p42(MAPK) expression. A concurrent growth retardation of HeLa cell line was observed in comparison with the control.</p><p><b>CONCLUSION</b>Inhibition of p42(MAPK) expression with siRNA technique can inhibit the proliferation of HeLa cells.</p>

Mechanism of augmented anti-tumor immunity in reconstituted lymphopenic mice immunized with melanoma vaccine / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore mechanisms of the augmented anti-tumor immunity observed in reconstituted lymphopenic mice (RLM) receiving melanoma vaccination.</p><p><b>METHODS</b>The study is to investigate the anti-tumor immunity of tumor vaccination during early immune reconstitution period following irradiation and cyclophosphamide (CY)-induced lymphopenia. Lymphopenic mice were subsequently reconstituted with naive splenocytes from syngeneic mice and immunized with irradiated melanoma cells F10 (irradiation experiment) and GM-CSF-modified D5 melanoma cells (D5-G6) (CY experiment). Controls included normal C57BL/6 mice receiving the corresponding vaccination, un-immunized naive mice and RLM. 8 - 10 days after vaccination, tumor vaccine draining lymph nodes (TVDLN) were harvested and phenotyped by FACS analysis. T cells purified from TVDLN were stimulated with anti-CD3 and anti-TCRbeta and proliferation was assessed by [(3)H]-TdR incorporation and FACS assay was performed for CD69 expression.</p><p><b>RESULTS</b>The augmented anti-tumor immunity correlated with a significant increase in the percentage of T cells with activation/memory phenotype in the TVDLN of vaccinated RLM, compared to that of the controls. There was also a significant increase in the density of DCs in TVDLNs. The activation threshold of T cells generated from vaccinated RLM was significantly decreased, resulting in markedly enhanced proliferating capability upon anti-CD3 stimulation.</p><p><b>CONCLUSION</b>This study suggests that the augmented anti-tumor immunity observed in vaccinated RLM is due to down regulated activation threshold of T cells during lymphopenia-driven T cell proliferation, which may in turn facilitate the breaking down of immune tolerance to weak tumor antigens upon vaccination with tumor cell vaccines.</p>

Mechanism of apoptosis induced by indole-3-acetic acids combined with horseradish peroxidase in leukemia cell line K562 / 中国实验血液学杂志

To investigate the possible mechanism of apoptosis induced by indole-3-acetic acid (IAA) combined with horseradish peroxidase in leukemia cell line K562, cell proliferation and apoptosis of K562 cell were examined by MTT assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), respectively; the activity of superoxide dismutase (SOD) and the quantitative change of MDA were measured by biochemical method; changes of free radical were determined by 2, 7-dichlorofluorescin diacetate (DCFH-DA) probe with confocal microscopy. The results showed that of MTT assay and TUNEL indicated that IAA/HRP could significantly inhibit cell proliferation (P < 0.05) and induce apoptosis of K562 cell (P < 0.01), at the same time a positive correlation was found between apoptosis rate and IAA concentration (r = 0.971, P < 0.01). The activity of SOD and the quantitative of MDA increased, accompanied with a rise in IAA concentration. Results detected by DCFH-DA probe indicated that the fluorescence intensity of intracellular free radical increased, as compared with control, and a positive correlation was found. It is concluded that IAA/HRP can inhibit proliferation of K562 cells and induce K562 cell apoptosis, its mechanism may be related with the increase of intracellular free radical due to the effects of IAA/HRP.

New strategy of cancer immunotherapy: irradiation or chemotherapeutics-induced lymphopenia combined with immune reconstitution and tumor vaccine / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To test whether vaccination performed during irradiation or chemotherapeutics-induced lymphopenia-driven T cell proliferation could augment the antitumor immunity.</p><p><b>METHODS</b>The study composed of two parts, investigating the anti-tumor efficacy of performing tumor vaccination during early immune reconstitution period following sublethal total body irradiation and cyclophosphamide (Cy)-induced lymphopenia, respectively. Mice were subsequently reconstituted with naïve splenocytes from syngeneic mice and were named RLM (Reconstituted lymphopenic mice). Immunization/vaccination (F10) and adoptive immunotherapy (D5-G6) were used to explore anti-tumor immune responses in vaccinated irradiation/RLM and vaccinated Cy/RLM, respectively. Both normal C57BL/6 mice and RLM were vaccinated with irradiated, weakly immunogenic F10 melanoma cells and subsequently challenged with F10 cells. In addition, to determine the role of CD4(+) and CD8(+) T cells in the protective anti-tumor immune response, irradiation/RLM were depleted of these subpopulations by administration of the appropriate mAb around challenge. In the second part, adoptive immunotherapy was used to evaluate the anti-tumor immune responses under chemotherapeutics-induced lymphopenic condition. Both normal mice and RLM (Cy-treated) were vaccinated with GM-CSF-modified D5 melanoma cells (D5-G6) and tumor vaccine draining lymph nodes (TVDLN) were harvested 9-10 days later. Effector T cells were generated in vitro from TVDLN cells and adoptively transferred to mice bearing 3-day pre-established pulmonary metastases (D5). Recipient mice were sacrificed 2 weeks later after tumor inoculation and pulmonary metastases were enumerated.</p><p><b>RESULTS</b>Significantly greater protection was induced in vaccinated irradiation/RLM, compared to vaccinated normal mice (63.2% vs 16.7%). Protective immunity in RLM depended on CD8(+) T cells. Increase in the interval between reconstitution and vaccination significantly decrease the protection. Effector T cells generated from vaccinated Cy-treated RLM demonstrated significantly higher in vivo anti-tumor efficacy over those of vaccinated normal mice.</p><p><b>CONCLUSION</b>This study suggests that vaccination of RLM could elicit augmented antitumor immunity compared to normal hosts, highlighting the potential clinical benefit of performing tumor vaccination during irradiation or chemotherapeutics-induced lymphopenia in cancer patients.</p>

Expression of IgVH and B7-1 in proteome of the human colorectal carcinoma cell lines / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To conduct a proteomic analysis of human colorectal carcinoma cell lines LS174T and SW480 by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS).</p><p><b>METHODS</b>The total proteins of human colorectal carcinoma cell lines LS174T and SW480 were separated with 2-DE using immobilized pH gradient strips and analyzed by MALDI-TOF-MS to obtain peptide mass fingerprints (PMFs). Proteins were identified by using Mascot software to search protein databases.</p><p><b>RESULTS</b>Good resolution 2-DE maps were obtained. Some proteins including immunoglobulin heavy chain variable region (IgVH) and co-stimulatory molecule B7-1 were identified. IgVH and B7-1 were confirmed by electrospray ionization tandem spectrometry (ESI-MS/MS) and immunocytochemistry.</p><p><b>CONCLUSION</b>There are IgVH and B7-1 expressions in human colorectal carcinoma cell lines LS174T and SW480. Results obtained will help to elucidate the mechanisms of tumor immune escape.</p>

Humoral immune response and in vitro neutralizing antibody assay on co-delivery of protein HPV16L1 virus-like particle with HPV16L1 gene / 中华病理学杂志

<p><b>OBJECTIVE</b>To compare humoral immune response by co-inoculating mice with antigen HPV16L1 virus-like particle (VLP) and HPV16L1 recombinant plasmids and then observing the neutralizing antibody activity in vitro.</p><p><b>METHODS</b>C57BL/6 mice were injected intramuscularly/subcutaneously with pcDNA-L1 plasmids plus HPV16L1 VLP. Serum IgG levels were detected by ELISA, antibody neutralizing protective activities were determined by hemagglutination inhibition and HPV16L1 VLP binding inhibition assay.</p><p><b>RESULTS</b>Serum antibody titers and neutralizing antibody activities were increased in HPV16L1 plasmids plus HPV16L1 VLP proteins in co-immunized mice when compared with controls.</p><p><b>CONCLUSION</b>Co-inoculation of the HPV16L1 VLP protein can enhance production of neutralizing antibody activities against aimed antigen, which should be a more promising strategy for effective HPV16 prophylactic vaccine development.</p>

Poorly-immunogenic tumor is capable of inducing proliferation of CD4 (+) CD25 (+) regulatory T-lymphocytes in vitro / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the distribution of regulatory T-lymphocytes in the splenocytes cocultured with syngeneic low-immunogenic tumor cells, as compared with that of highly-immunogenic tumor cells, to investigate the mechanism underlining tumor evasion.</p><p><b>METHODS</b>Three different immunogenic tumor cells were cocultured with syngeneic splenocytes individually to mimic cancer immunity in vitro. The proliferation response of splenocytes was measured by thymidine incorporation. The distribution of TR cells, CD4(+) IFN-gamma (+) T cells and CD4(+) IL-10(+) T cells were analyzed by flow cytometry. The secretion of IFN-gamma and IL-10 in supernatants was measured by ELISA assay.</p><p><b>RESULTS</b>The stimulation Index of splenocytes cocultured with syngeneic highly-immunogenic H22 or FBL3 was much higher than that of poorly immunogenic melanoma D5. In each group, stimulation Index of splenocytes cocultured with allogeneic tumor cells was higher than that of the corresponding tumor immunity model. In addition, compared with those of highly-immunogenic tumors, there were more TR, CD4(+)IL-10(+) and less CD4 (+)IFN-gamma(+) T cells in the splenocytes, and higher IL-10 and lower IFN-gamma levels in the supernatant of the splenocytes stimulated with low-immunogenic D5 cells.</p><p><b>CONCLUSION</b>Poorly-immunogenic tumor cells can induce the proliferation of TR cells, which may play an important role in tumor evasion.</p>

Carboxyl terminus truncated HPV58 virus L1 protein expressed with baculovirus system and its bioactivity / 生物工程学报

To prepare carboxyl terminus truncated human papillomavirus type 58L1 protein, and study on its in vitro bioactivity. PCR was used to amplify carboxyl terminus truncated HPV 58L1 gene, the product was inserted into the PUCMT cloning vector, preparing recombinant PFastBacHTb containing carboxyl terminus truncated HPV58L1 gene. Further more, the recombinant plasmid PfastbacHTb was used to transform DH10Bac cells, constructing recombinant Baculovirus, then the recombinant virus was successfully used to infect Sf-9 insect cells. After incubating at 27 degrees C for 72 hours, the infected cells were collected and total cellular proteins were extracted. The target protein with MW 58KD was revealed by SDS-PAGE and confirmed by Western blot. The interested protein was purified by ProBond purification system. The purified interested protein was identified to self-assemble into VLPs by Transmission electron microscope, and induce murine erythrocyte hemagglutination, indicating that the given proteins had the conformation of VLPs, collecting, HPV58L1 proteins with carboxyl terminus truncation could be efficiently expressed in baculovirus Sf-9 cells expression system, it has identical in vitro bioactivity to the wild type HPV58L1, The present study is fundmental for preparing HPV58L1 prophylactic vaccine.

Preliminary study of HPV16 L1/E6-E7 chimeric recombinant DNA vaccine plasmid construction and expression in CHO cell / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To develop HPV16 L1/E6 and L1/E7 prophylactic and therapeutic DNA vaccines.</p><p><b>METHODS</b>The nucleotides within HPV 16 E6 and E7 genes, which are responsible for viral transforming activity, were mutated by mega primer site-directed mutagenesis method. The correctly mutated E6 and E7 fragments were separately cloned into an eukaryotic expression vector pVAX1, together with HPV 16 L1 gene, generating chimeric recombinants plasmids 1MpVAX1-L1E6, 2MpVAX1-L1E6, 1MpVAX1-L1E7, 2MpVAX1-L1E7 and 3MpVAX1-L1E7. CHO cells were transiently transfected with the individual DNA vaccines by calcium phosphate method. Target protein expressions in the extracts of the transfected cell lines were measured by ELISA and immunohistochemistry, with HPV 16 L1 and E6 specific monoclonal antibodies.</p><p><b>RESULTS</b>ELISA showed the P/N ratios in the cell extracts transfected with L1E6 and L1E7 plasmids were greater than 2.1. Immunohistochemistry revealed brownish precipitant signal in cytoplasm and nuclei of the transfected cells.</p><p><b>CONCLUSIONS</b>Successful constructions of prophylactic and therapeutic DNA vaccine plasmids may be useful for future animal experiment and clinical trial.</p>