Construction and Expression of Prokaryotic Expression Vector of MPT-64 Gene

[Objective]Protective antigen gene MPT-64 was cloned from genomic DNA of Mycobacterium tuberculosis and transferred into prokaryotic competent cells for expression to obtain MPT-64 fusion protein.[Method]Based on the GenBank,primers were designed for amplification of MPT-64 gene,and the recombinant plasmid pET-32a-MPT-64 was constructed.The recombinant plasmid was expressed in prokaryotic expression vector to obtain fusion protein.[Result]Protective antigen gene MPT-64 was successfully cloned.The recombinant plasmid pET-32a-MPT-64 was obtained.MPT-64 fusion protein was successfully expressed.[Conclusion]This study laid solid foundation for the prevention,diagnosis,treatment of tuberculosis and the development of tuberculosis vaccines.

Antigen Gene Cloning and Expression of HIV-1 for AIDS Vaccine Design Ⅲ. HIV-1 Antigen Gene Cloning, in Vitro Expression and Antibody Induction

Objective: To evaluate the humoral immune induction in rats of a candidate AIDS vaccine expressing the gag p24 gene froma subtype B HIV-1 isolate. Methods: The amplified p24 gene was inserted into aneukaryotic expression vector to form the supercoiled DNAvaccine. The linearized expressed DNA vaccine was preparedfrom the expression plasmid by polymerase chain reaction(PCR). The antigen gene expression in rats of the linearizedand supercoiled DNA vaccines were in vitro and in vivodetected. Results: In vitro transcription and Northern hybridizationshowed that the linearized DNA vaccine could synthesizeamounts or p24 mRNA similar to the supercoiled DNA vaccine.Antibody assays of inoculated rats confirmed that thelinearized expression DNA could induce a slightly higherantibody titer than the expression plasmid, while the highestautibody titer had been induced by plasmid plus adjuvantinoculation. Conclusion: The construction of a candidate AIDS vaccinebased on the p24 gene could shed light on a potential IV vaccine, meriting evaluation in a rhesus macaque SHIV-AIDSmodel.

Antigen Gene Cloning and Expression of HIV-1 Toward an AIDS Vaccine Design Ⅰ.Amplification and Sequencing of HIV-1 Antigen Genes

Objective:To amplify antigen genes from patients with human immunodeficiency virus type 1 (HIV-1) in Guangdong Province for candidate AIDS vaccine design. Methods:Viral nucleic acid was isolated from 10 HIV-1 infected individuals' peripheral blood collected during 1995-2000 in Guangdong Province. The viral gag p24 gene and env gp120 gene were amplified by nested-PCR and sequenced. The homologies among HIV-1 isolates were compared with HIV-BLAST. Results: Among 10 HIV-1 isolates, nine are homologous to viruses of subtype B, and one is homologous to viruses of subtype E. Conclusion: Subtype B viruses of HIV-1 are predominantly present in Guangdong Province.

Anti-tumor effects induced by gene vaccines co-expressing truncated human prostate specific membrane antigen gene and mouse 4-1BBL

Objective To investigate the influence of m4-1BBL on anti-tumor effects induced by truncated human prostate specific membrane antigen ( tPSMA ) gene in mice. Methods A eukaryotic expression plasmid encoding tPSMA and m4-1BBL ( pDC316-tPSMA-IRES m4-1BBL) ,pDC316-tPSMA and pDC316 were constructed.

GENE ENGINEERING EB VIRUS MEMBRANE ANTIGEN IN DETECTION OF MA-IgA ANTIBODY(COMPARISON WITH VCA-IgA AND EA-IgA ANTIBODIES)

With gene engineering EB virus membrane antigen as the diagnostic antigen, indirect immunofluo-rescence (IF) assay was used to detect IgA antibody against EB virus membrane antigen (MA-IgA) in sera from 202 nasopharyngeal carcinoma (NPC) patients and 315 controls (normal and patients with other tumors). MA-IgA antibody was positive in 96.8% of the pretreatment NPC patients with a GMT of 1:36.3. MA-IgA detection by this method was more sensitive than EA-IgA detection by IE. In contrast, patients with tumors other than NPC were negative for MA-IgA antibody. 9.1% of VCA-IgA positive persons were MA-IgA positive with a GMT of less than 1:5. No MA-IgA positive was found in VCA-IgA negatives. The results indicated that this method was relatively specific. In the treatment group, the positive rate and GMT of MA-IgA antibody declined with increase in survival time and the decline was faster than VCA-IgA. When recurrence or distant metastasis developed, similar to VCA-IgA and EA-IgA antibodies, the positive rate and GMT of MA-IgA antibody increased to its pretreatment level. Therefore, MA-IgA detection might be valuable in the early diagnosis and monitor of NPC.

Identification and Characterization of Hepatitis B Virus Immune Escape Mutants in Kenya

Hepatitis B Virus (HBV) infections affect about 400 million people globally and cause about 1.4 million deaths annually. The virus displays high levels of genetic variations/mutations, some of which are immune escape mutants. The prevalence of HBV infection in Kenya is high at about 8%. This study aimed at identifying and characterizing HBV immune escape mutants in Kenya. From 547 HBV sequences available in Kenya in NCBI, and HBVdb databases in July 2021, 120 full sequences were retrieved. The S gene sequences at position 1-225, which included the “a” determinant region of the gene were analyzed using various bioinformatics tools such as Bioedit software, and Emboss Cons. The clinical significance was flagged from the search of peer-reviewed journals. Forty-six HBV-positive blood donor samples were obtained from the Kenya National Blood Transfusion Services without personal identifiers, DNA extracted, and sequenced targeting positions 1 to 520 of S genes. Mutations were similarly identified from seventeen sequences after cleaning and analysis. Out of 120 sequences that were extracted from databases and analyzed, 79 different mutations were identified. Fifteen of them were of clinical importance with an occurrence frequency of at least 5% were obtained. The majority (64.6%, n = 51), with S207N and A194V being most dominant, could result in immune escape and reduced HBsAg detection signals while 24.1% (n = 19) could result in immune escape/reduced HBsAg detection signals and high probability of hepatocellular carcinoma. Most likely to occur on the amino acids Alanine, Lysine, Serine, Asparagine, and Valine in decreasing order. The most dominant genotype was found to be Genotype A (N = 10), while four sequences were Genotype D. In contrast to the in-silico studies, the sequences from HBV samples from blood donors did not demonstrate the presence of S207N and A194V mutations and all the genotypes were type A1. Only two (13.3%) samples showed the same mutations of sK122R and sT143S for both in-silico analysis and actual sequenced samples. This study did not identify G145R mutation which is the commonest mutation within the HBsAg immunodominant “a” determinant that is associated with immune escape. The concordance of mutations in “a” determinant region of HBsAg gene among various studies is minimal. The study identified new mutations (sA194Y, sS207, sA194S, sS207I, sP46A, sA194T, sS207I, sP46R, and sT143P) that had not been published before. Four (20%) of the mutations were clinically significant. These included sS207R, sT143S, sC76F and sK122R.

Construction of cDNA Library from NPC Tissue and Screening of Antigenic Genes

To construct cDNA library of nasopharyngeal carcinoma （NPC） and obtain the NPC associated or specific antigens from it, we used a powerful new method to identify the antigens eliciting humoral immune response, which is SEREX （serological identification of antigen by recombinant cDNA expression library）. Autologous serum of NPC patient was used to screen the reactive clones in the human NPC tissue cDNA library consisted of 3.64 × 10^6 recombinants. The 23 exact positive clones were subcloned to monoclonality and the size of cDNA inserts was identified by PCR. Then the nucleotide sequence of cDNA inserts was determined, and the sequence alignments were performed with BLAST software on GenBank database. They represented 16 different antigens. A detailed sequence analysis showed that 10 of 16 genes were high homologous to genes known in GenBank, such as RPL31, SI00 A2, MT2A, etc. However, there were also 6 genes with low homology to genes in GenBank. Furthermore, 3 of 6 genes may be novel genes. The associations of these genes to NPC and the roles that they played in the occurrence and development of NPC should be further revealed.

The Construction of Schistosoma Japonicum Vaccine BCG-Sj26GST and Its Identification

Summary: The expression of foreign gene, Schistosoma Japonicum 26 ku antigen (Sj26GST), in Bacillus Calmette Guerin (BCG), Mycobacterium ( M. smegmatis ) and Escherichia coli ( E. coli ) were studied. The cDNA fragment encoding Sj26GST was amplified by PCR using plasmid pGEX, which could express Sj26GST in E. coli as template. The Sj26GST cDNA was cloned into the downstream of human M. tuberculosis heat shock protein (hsp) 70 promoter with correct reading frame, and then the DNA fragment containing hsp70 promoter and Sj26GST gene were subcloned together into E. coli Mycobacteria shuttle plasmid pBCG 2000 to construct the expression shuttle plasmid pBCG Sj26. The recombinant BCG and M. smegmatis mc 2 155, which were electroplated with pBCG Sj26, could express Sj26GST and the recombinant Schistosoma Japonicum vaccine BCG Sj26GST was made. The recombinant Sj26GST (rSj26GST) were soluble and could be observed on SDS PAGE at molecular weight of 26 ku. The content of rSj26GST accounted for 15 % and 10 % of total bacterial protein in BCG and M. smegmatis respectively. The results of Western blot showed the combination of rSj26GST with antibody of GST.

Association of HLA Alleles(A, B, DRB1) and HIV-1 Infection in the Han Population of Hubei, China

The HIV susceptibility and resistance alleles in the HLA genes were determined by investigating the distribution characteristics of the HLA alleles（A, B, and DRB1） in HIV-infected individuals of the Han population in Hubei, and by comparing these alleles with HIV-negative individuals from the same area. A cohort of 424 HIV-1 infected individuals were chosen as study subjects, and 836 HIV-negative healthy subjects from the same area served as the control population. HLA-A, B, and DRB1 allele typing was performed using polymerase chain reaction-sequence-specific oligonucleotide probes（PCR-SSOP） and polymerase chain reaction-sequencing based typing（PCR-SBT） techniques. Arlequin ver3.0 was used to analyze the allele and haplotype frequencies of HLA-A, B, and DRB 1, whereas Epi Info 7 and SPSS18.0 was used to analyze the differences in the HLA alleles between the HIV-1 positive and HIV-1 negative groups. A＊02：03, DRB1＊01：01, and DRB1＊15：01 alleles and their haplotypes as well as the HLA_Bw4-Bw6 hybrid showed a protective effect on HIV-1 infection. After adjusting for confounding factors such as age and sex, multivariate logistic regression analysis revealed that B＊15：02G, DRB1＊01：01, and DRB1＊15：01 subtypes were the resistance genes of HIV-1 infection, while B＊13：01 might increase susceptibility to HIV-1 infection. The correlation between A＊02：06 and B＊15：01G subtypes and HIV-1 susceptibility was independent of the age and sex of the host. This study demonstrated the influence of genetic factors in humans such as HLA polymorphism on individuals to resist HIV-1 infection. Association studies of HLA polymorphism, susceptibility/resistance to HIV-1 infection, and hosts＇ genetic background are of significant importance for research on HIV-1 pathogenesis and vaccine design.

A Researches on DLA-DRB1 Genotyping by PCR-RFLP Ⅱ.A Study of Serology and Cellularly Defined DLA Haplotypes and Their Segregation

The polymerase chain reaction based restriction fragment length polymorphism (FCR-RFLP)method was used to study DLA class Ⅱgene n dogs.Genomic DNA from 11 DLA homozygous reference dogs representing 8 different haplotypes and 2 families with a total of 16 animals were amplified by the oligonuclectide primer pair (HLA-DRB-AMP-A/B) cross-hybriding HLA-DRB specific and fit for the amplification of DLA-DRE1 gene.The corresponding amplified DNA products were 235 base pairs[1].Amplified DNA was digested by 32 different restriction endonucleasts,whith could recognize allelic variations within DLA-DRB.After digesting only with Hae Ⅲ,HhaI,HitfI,RsaIand Sau96 high polymorphism was revealed respectively and 9 distinct RFLP pattern wert shown, which could be correate to the DLA haplotypes studied. The 8 cellular established DLA-D specificities presentin the reference panel were defined unequivocally by PCR-RFLP and correlated with DLADw5 and Dw6 two subtypes.The segregation pattern of four different DLA-DRE types could be demonstrated in two families.Based on these data we conclude that PCRRFLP typing utilizing the above mentioned priiner pair and endonuleases is a valuable tool to define DLA class Ⅱ types in the dog.

Protective effect of DNA-mediated immunization with a combination of SAG1 and IL-2 gene adjuvant against infection of Toxoplasma gondii in mice

To characterize the immune response induced by SAG1 encoding plasmid combined with IL 2 gene adjuvant in mice and to assess the protective effect of this vaccination against toxoplasmosis Methods Mice were co injected intramuscularly with plasmid encoding Toxoplasma gondii SAG1 plus murine IL 2 expression vector at a dose of 100 μg Booster immunizations were employed 2 more times at 3 week interval As controls, mice were inoculated with PBS or empty plasmid pcDNA3 Humoral and cellular responses were assayed using ELISA for the determination of Ab, Ab isotype and IFN γ, as well as IL 4 To detect the integration and dissemination of DNA in the injected mice, PCR and in situ hybridization were performed All mice were then infected with highly virulent RH tachyzoites of Toxoplasma gondii intraperitoneally Results Significant increases in specific IgG levels were observed in mice after immunization three times with SAG1 expression plasmid With respect to the IgG isotype, co inoculation of IL 2 expression plasmid enhanced the level of IgG2a and the production of IFN γ Challenging mice by vaccinating with combined plasmids with RH tachyzoites resulted in prolonged survival Conclusion Humoral and cytokine responses elicited by SAG1 DNA immunization can be modulated by co inoculation with IL 2 expression plasmid The use of DNA vaccine in combination with an appropriate cytokine gene to prevent T gondii infection warrants further investigation

Growth inhibiting effects of antisense eukaryotic expression vector of proliferating cell nuclear antigen gene on human bladder cancer cells

Objective To explore the growth inhibiting effects on human bladder cancer by antisense RNA targeting the proliferating cell nuclear antigen (PCNA) gene. Methods The eukaryotic expression vector for antisense PCNA cDNA was constructed and transferred into a bladder cancer EJ cell line. The PCNA expression in the cancer cells was detected by RT-PCR and Western blotting assays. The in vitro proliferation activities of the transferred cells were observed by growth curve,tetrazolium bromide (MTT) colorimetry,tritiated thymidine ( 3H-TdR)incorporation, flow cytometry and clone formation testing,while its in vivo anti-tumor effects were detected on nude mice allograft models.Results After the antisense vector,pLAPSN,was transferred,cellular PCNA expression was inhibited at both protein and mRNA levels. The growth rates of EJ cells were reduced from 27.91% to 62.07% ( P <0.01),with an inhibition of DNA synthesis rate by 52.31% ( P <0.01). Transferred cells were blocked at G 0/G 1 phases in cell-cycle assay,with the clone formation ability decreased by 50.81% ( P <0.01). The in vivo carcinogenic abilities of the transferred cancer cells were decreased by 54.23% ( P <0.05). Conclusions Antisense PCNA gene transfer could inhibit the growth of bladder cancer cells in vitro and in vivo,which provided an ideal strategy for gene therapy of human cancers.

Polymorphisms of TAP, LMP and HLA-DM genes in the Chinese

Objective To investigate the distribution of antigen processing genes transporter associated with antigen processing (TAP), low molecular weight proteasome (LMP2) and HLA DM in the Shanghai population and to explore the possible role of these genes in the genetic susceptibility to autoimmune diseases IgA nephropathy(IgAN) and multiple sclerosis(MS) Methods Eighty normal Shanghai Chinese, 60 patients with IgAN and 21 patients with MS were randomly selected and genotyped for antigen processing genes (TAP1, TAP2, LMP2, HLA DMA and DMB) using polymerase chain reaction sequence specific oligonucleotide (PCR SSO) and polymerase chain reaction restriction fragment length polymorphism (PCR RFLP) Two locus linkage disequilibrium analysis was performed Results Four TAP1, 6 TAP2, 2 LMP2, 3 DMA and 4 DMB alleles were observed Statistically significant associations were found between TAP1B TAP2A, TAP1B LMP2H and TAP2D HLA DMA *0101 ( Pc <0 01) There was no association between antigen processing genes and either IgAN or MS Conclusion The polymorphisms of antigen processing genes in this Shanghai population are similar to those observed in the other ethnic populations No association was found between IgAN or MS and any antigen processing genes tested in Shanghai population

Spotlight on chimeric antigen receptor engineered T cell research and clinical trials in China

T cell mediated adoptive immune response has been characterized as the key to anti-tumor immunity. Scientists around the world including in China, have been trying to harness the power of T cells against tumors for decades. Recently, the biosynthetic chimeric antigen receptor engineered T cell(CAR-T) strategy was developed and exhibited encouraging clinical efficacy, especially in hematological malignancies. Chimeric antigen receptor research reports began in 2009 in China according to our Pub Med search results. Clinical trials have been ongoing in China since 2013 according to the trial registrations on clinicaltrials.gov.. After years of assiduous efforts, research and clinical scientists in China have made their own achievements in the CAR-T therapy field. In this review, we aim to highlight CAR-T research and clinical trials in China, to provide an informative reference for colleagues in the field.