[Tumor vaccines-therapeutic vaccination against cancer]. / Tumorvakzinierung ­ therapeutische Vakzinierung gegen Krebs.

Tumor cells always exhibit differences to normal cells. These differences can be recognized by the immune system, enabling the destruction of tumor cells by T cells, as was impressively demonstrated by the success of immune checkpoint inhibition, e.g., in malignant melanoma. Many cancers, however, do not respond to this kind of therapy. In these cases, vaccination against tumor antigens could be very helpful. Nevertheless, all of the efforts made in this respect during the past 30 years have been virtually futile. With current knowledge and technology there is new hope.

Vacunas terapéuticas del virus del papiloma humano: revisión de la evidencia actual / Therapeutic vaccines of the human papilloma virus: current evidence review

Resumen: OBJETIVO: Evaluar la inmunogenicidad de los distintos tipos de vacunas terapéuticas y de su efecto en las lesiones causadas por el virus del papiloma humano (VPH) después de su aplicación. Además, analizar los estudios de seguridad y las perspectivas de las vacunas terapéuticas contra el VPH. METODOLOGÍA: Estudio retrospectivo efectuado mediante la búsqueda bibliográfica sistemática en la base de datos PubMed, sin restricción de fecha de publicación. Criterio de inclusión: ensayos clínicos aleatorizados (metanálisis y revisiones sistemáticas). Criterios de exclusión: ensayos clínicos en fase preclínica del desarrollo y publicaciones en idiomas distintos al inglés o español. RESULTADOS: Se seleccionaron 30 artículos publicados entre 2000 y 2020. Entre ellos, 5 ensayos clínicos aleatorizados con vacunas terapéuticas que ya han finalizado o aún están en estudio. Las 25 publicaciones restantes incluyen: metanálisis y revisiones sistemáticas de aspectos seleccionados con objetivos primarios y secundarios. CONCLUSIONES: Las vacunas terapéuticas contra VPH se encuentran en fase experimental; hasta ahora se han conseguido resultados prometedores con algunas de ellas. Si bien existen distintos tipos de vacunas terapéuticas, los mejores resultados se han conseguido con las basadas en ADN. Las vacunas VGX-3100 y TS, en fase III, han demostrado diferencias significativas en el aclaramiento viral y la regresión de las lesiones de alto grado en pacientes vacunadas. Una vacuna terapéutica efectiva tendría una repercusión inmediata en la morbilidad y mortalidad por lesiones asociadas al virus.

Abstract: OBJECTIVE: To assess the immunogenicity of different types of therapeutic vaccines and their effect on human papillomavirus (HPV) lesions after application. In addition, to analyze the safety studies and prospects of therapeutic HPV vaccines. METHODOLOGY: Retrospective study based on a systematic literature search of the PubMed database, with no publication date restrictions. Inclusion criteria: randomized clinical trials (meta-analyses and systematic reviews). Exclusion criteria: clinical trials in the pre-clinical phase of development and publications in languages other than English or Spanish. RESULTS: 30 articles published between 2000 and 2020 were selected. Among them, 5 randomized clinical trials with therapeutic vaccines that have already been completed or are still under study. The remaining 25 publications include: meta-analyses and systematic reviews of selected aspects with primary and secondary objectives. CONCLUSIONS: Therapeutic HPV vaccines are in the experimental phase; so far promising results have been achieved with some of them. Although different types of therapeutic vaccines exist, the best results have been achieved with DNA-based vaccines. The VGX-3100 and TS vaccines, in phase III, have demonstrated significant differences in viral clearance and regression of high-grade lesions in vaccinated patients. An effective therapeutic vaccine would have an immediate impact on morbidity and mortality from virus-associated lesions.

Avances en el desarrollo de una vacuna efectiva contra Cryptosporidium parvum: una revisión de la literatura / Advances in the development of an effective vaccine against Cryptosporidium parvum: An review of the literature / Avanços no desenvolvimento de uma vacina eficaz contra Cryptosporidium parvum: uma revisão da literatura

Introducción. Cryptosporidium parvum es un parásito zoonótico altamente prevalente, asociado a enfermedad diarreica en población inmunocomprometida, niños y terneros menores de 30 días. Esta infección puede ocasionar deshidratación, alteración del estado de conciencia, retraso en el desarrollo global y, en algunos casos, la muerte del paciente. A pesar de la alta prevalencia de C. parvum, no existen medicamentos completamente efectivos ni una vacuna aprobada para prevenir dicha enfermedad. Objetivo. Realizar una revisión de la literatura sobre candidatos vacunales contra C. parvum. Método. Revisión documental mediante la búsqueda de la literatura de los últimos 20 años, disponible en las bases de datos PubMed central, WEB OF SCIENCE, Embase, REDALYC y LILACS. Resultados. Las vacunas atenuadas, recombinantes, basadas en ADN, expresadas en vectores bacterianos y sintéticas han mostrado resultados prometedores en la inducción de inmunogenicidad contra los antígenos de C. parvum, siendo el antígeno de superficie de 15 kilodaltons de Cryptosporidium parvum (cp15), el antígeno inductor de una mejor respuesta inmune celular y humoral en el modelo murino estudiado. Conclusión. Se espera que la incorporación de nuevas técnicas para la selección de antígenos promisorios y la ejecución de una gran cantidad de ensayos in vivo, favorezcan el desarrollo de una vacuna totalmente efectiva contra C. parvum. Aunque el camino para lograr este objetivo será largo y difícil, se convierte en la mejor alternativa para controlar una de las enfermedades de interés en salud pública, con mayor impacto en la población inmunocomprometida.

Introduction. Cryptosporidium parvum is a highly prevalent zoonotic parasite, associated with diarrheal disease in immunocompromised population, children and calves under 30 days. This infection is associa- ted to dehydration, delayed global development and, in some cases, the death of the patient. Despite the high prevalence of C. parvum, there are no fully effective medications and an approved vaccine to prevent such disease. Objective. To conduct a thorough review of the literature on vaccine candidates against C. parvum. Method Documentary review by searching the literature of the last 20 years, available in the central PubMed, WEB OF SCIENCE, Embase, REDALYC and LILACS databases. Results. Attenuated, recombinant, DNA-based, expressed in bacterial vectors and synthetic vaccines have shown promising results in inducing immunogenicity against C. parvum, being the Cryptospori- dium parvum 15 kiloDalton surface antigen (cp15), the antigen inducer of a better cellular and humoral immune response in the murine model studied. Conclusion. It is expected that the incorporation of new techniques for the selection of promising antigens and the execution of a large number of in vivo assays will favor the development of a fully effective vaccine against C. parvum. Although the way to achieve this goal will be long and difficult, it will become the best alternative to control one of the diseases with the greatest impact on the immu- nocompromised population.

Introdução. O Cryptosporidium parvum é um parasita zoonótico de alta prevalência associado à doença diarreica em populações imunocomprometidas, crianças e bezerros com menos de 30 dias. Essa infecção pode causar desidratação, alteração do estado de consciência, atraso no desenvolvi- mento global e, em alguns casos, a morte do paciente. Apesar da alta prevalência de C. parvum, não existem medicamentos totalmente eficazes e uma vacina aprovada para prevenir a doença. Objetivo. Realizar uma revisão literária dos candidatos à vacina contra C. parvum. Método. Revisão documental, mediante pesquisa da literatura dos últimos 20 anos, disponível nas bases de dados PubMed central, WEB OF SCIENCE, Embase, REDALYC e LILACS. Resultados. Vacinas atenuadas, recombinantes e baseadas em DNA, expressas em vetores bacteria- nos e sintéticos, mostraram resultados promissores na indução de imunogenicidade contra antígenos de C. parvum, sendo o antígeno de superfície de 15 kilodaltons de Cryptosporidium parvum (cp15) o antígeno indutor de uma melhor resposta imune celular e humoral no modelo murino estudado. Conclusão. Se espera que a incorporação de novas técnicas para a seleção de antígenos promissores e a execução de um grande número de ensaios in vivo favoreçam o desenvolvimento de uma vacina totalmente eficaz contra C. parvum. Embora o caminho para alcançar este objetivo seja longo e difícil, torna-se a melhor alternativa para controlar uma das doenças de interesse na saúde pública com maior impacto na população imunocomprometida.

Study on immune effect of DNA vaccine pIRES2-MLAA34-HSP70 constructed by SOE-PCR / 重庆医学

Objective To construct the DNA vaccine pIRES2-MLAA34-HSP70,and to detect its immune effect.Methods The acute monocytic leukemia associated antigen gene MLAA-34 and heat-shock protein (HSP)70 gene were extracted by using RT-PCR.The specific overlapping primer was designed,and the fusion gene MLAA34-HSP70 was amplified by using SOE-PCR technique.Then the DNA vaccine pIRES2-MLAA34-HSP70 was constructed,and BALB/c mice were immunized with this DNA vaccine.The splenic lymphocyte killing activity was detected by using MTT,levels of IL-2,IL-4 and IFN-γ were also detected by using ELISA.Results The MLAA34-HSP70 gene (2 956 bp) and the DNA vaccine pIRES2-MLAA34-HSP70 was amplified and constructed successfully.The killing efficiency of DNA vaccine pIRES2-MLAA34-HSP70 in U937 cells was significantly higher than that in other experimental groups and control group (P＜0.01),and levels of IL-4,IL-2 and IFN-γin DNA vaccine pIRES2-MLAA34-HSP70 group were significantly higher than those in the other experimental groups and control group (P＜0.01).Conclnsion The DNA vaccine pIRES2-MLAA34-HSP70 is constructed successfully.It is shown that the DNA vaccine induces strong humoral immunity,which could enhance immune responses to tumor cells and specificlly kill MLAA34 positive cells.

Construction of a DNA Vaccine Encoding Mtb32C and HBHA Genes of Mycobacterium tuberculosis.

BACKGROUND: Tuberculosis (TB) is a contagious disease caused by Mycobacterium tuberculosis. Development of a new vaccine for tuberculosis requires immunogenic antigens capable of inducing suitable and long-lasting T cell immunity. The emergence of multidrugs and extensively drug-resistant strains of M. tuberculosis has made it a global public health concern. OBJECTIVES: DNA vaccine is a straightforward method to introduce antigens to the host. In the present study, two immunodominant mycobacterial antigens (Mtb32C and HBHA) were isolated and cloned into pcDNA3.1 (+) to design and construct a new DNA vaccine. This vector is capable of producing new potent chimeric protein. MATERIALS AND METHODS: Mtb32C (Rv0125) and heparin-binding haemagglutinin adhesion (HBHA) genes were amplified using polymerase chain reaction (PCR) of M. tuberculosis H37Rv genome and ligated into pcDNA3.1 (+). Colony-PCR and restriction enzyme analysis were used to confirm the accuracy of the cloning procedure. RESULTS: In the current study, recombinant pcDNA3.1 (+) vector containing Mtb32C and HBHA genes was successfully constructed. The desired size of DNA fragment was observed using single and double digestion methods. CONCLUSIONS: Mtb32C and HBHA genes were successfully isolated from H37Rv genome and cloned into an eukaryotic expression vector. This vector can be considered as a vaccine to evaluate immune responses in animal models.

kgp, rgpA, and rgpB DNA vaccines induce antibody responses in experimental peri-implantitis.

BACKGROUND: Peri-implantitis is the key factor for implant failure. This study aims to evaluate kgp, rgpA, and rgpB DNA vaccines to induce an immune response and prevent peri-implantitis. METHODS: The kgp, rgpA, and rgpB genes were amplified by polymerase chain reaction (PCR) from Porphyromonas gingivalis (Pg) ATCC 33277 and cloned into the pVAX1 vector. Titanium implants were placed into the mandibular bone of dogs. Three months later, the animals were divided into four groups, immunized with pVAX1-kgp, pVAX1-rgpA, pVAX1-rgpB, or pVAX1. Cotton ligatures infiltrated with Pg were tied around the neck of the implants. Immunoglobulin (Ig)G and IgA antibodies were detected by enzyme-linked immunosorbent assay before and after immunization. RESULTS: The kgp, rgpA, and rgpB genes were successfully cloned into the pVAX1 plasmid. Animals immunized with pVAX1-kgp and pVAX1-rgpA showed higher titers of IgG and IgA antibodies compared to those before immunization (P <0.05) and compared to those that were immunized with pVAX1 and pVAX1-rgpB, whereas there were no significant differences in the animals treated with pVAX1 and pVAX1-rgpB. Furthermore, among these, the kgp DNA vaccine was more effective. The bone losses of the groups with pVAX1-kgp and pVAX1-rgpA were significantly attenuated. CONCLUSION: pVAX1-kgp and pVAX1-rgpA DNA vaccines enhanced immunity responses and significantly retarded bone loss in experimental peri-implantitis animal models, whereas pVAX1-rgpB was ineffective.

Preliminary observation on antitumor effect of HPV58 composite DNA vaccine / 中华妇产科杂志

Objective To initially observe the antitumor immune of PVAX1-HPV58mE6E7FcGB composite DNA vaccine.Methods Before detecting immune effect of the vaccine,the B16-HPV58E6E7 tumor cell line was built which could steadily express HPV58E6E7 fusion gene.Then,HPV58E6E7-GST fusion protein as an antigen was expressed and purified.Before or after immunized with the vaccine,the C57BL/6 mice were challenged by B16-HPV58E6E7 cells.Anti-tumor transplantation and tumor growth inhibition experiment were performed to observe prevention and treatment effects on the vaccine.Specific humoral and cellular immune responses in the immunized mice were detected by ELISA,enzyme linked immunospot assay (ELISPOT) and cytotoxic T lymphocyte (CTL) method.Results In the anti-tumor transplantation experiment,tumor formation rate was only 9/15 in the mice which were immunized by PVAX1-HPV58mE6E7FcGB vaccine,time before tumor formation was the longest [(13.6 ± 1.7) days] and tumor growth was the slowest in the vaccine group.In tumor growth inhibition experiment,inhibition rate reached 81.4％ in the vaccine group.Except tumor formation rate,all data in the vaccine group was superior to the pure antigen PVAX1-HPV58mE6E7Fc group (P ＜ 0.05).Humoral immune effect showed that both the vaccine and the pure antigen could induce specific antibody in the immunized mice,and the highest titer were 1 ∶ 25600 and 1 ∶ 12800,respectively.Although there was not significant difference of antibody titer between the vaccine and the pure antigen group (P ＞ 0.05),the number of activated T cells in the vaccine group was almost four times as that in the pure antigen group [(219 ±34)/4 × 105 spleen lymphocytes versus (55 ±25)/4 × 105 spleen lymphocytes,P ＜ 0.05],and the highest specific CTL that vaccine induced was significantly higher than that of pure antigen (43.3％ versus 31.3％,P ＜ 0.05).Conclusions Humoral and cellular immune response could be effectively stimulated by PVAX1-HPV58mE6E7FcGB composite DNA vaccine.Growth of B16-HPV58E6E7 cells was significantly inhibited in the immunized mice.The cellular immune effect on the vaccine was superior to the pure antigen.Therefore,PVAX1-HPV58mE6E7FcGB could be used as a candidate vaccine for immune therapy to the HPV58 positive tumors and precancerous lesions.

Construction and identification of a eukaryotic expression vector of fusion protein containing avian H5N1 influenza virus hemagglutinin antigen and the cholera toxin B subunit / 中华传染病杂志

Objective To construct a eukaryotic vector which contains avian H5N1 influenza virus hemagglutinin (HA) antigen and the cholera toxin B subunit (CTB) and to investigate its expression in COS7 cells,and the ability to induce specific immune responses in vivo in different periods.Methods After cloned by polymerase chain reaction (PCR),CTB and HA genes were digested with BamH Ⅰ and connected into CTB-HA gene with T4 ligase.The connected gene was referred to as CH.After double digestion,CH gene was inserted into a eukaryotic recombinant plasmid pCI-neo.The pCI-CH plasmid was then transfected into COS7 cells.Western blot was used to detect the expression of HA antigen.After New Zealand white rabbits were immunized,the titer of HA antigen-specific antibody in serum and its specificity with other strains such as H1N1,H9N1,H3N2 and influenza B virus were determined by indirect enzyme-linked immunosorbent assay.Results The pCI-CH vector (DNA vaccine) was successfully constructed,which could be efficiently expressed in COS7 cells and induce specific antibodies against pCI-CH in rabbits.Cross reactions indicated that DNA vaccine pCI-CH specific antisera could not only react with H5N1 strain (P/N＞2.1),but also H1N1,H9N1 and H3N2 strains,but did not cross react with influenza B virus.Conclusion The newly constructed avian H5N1 influenza virus nucleic acid vaccine has good immunogenicity.

Immunogenicity evaluation of a recombinant adenovirus containing the PIB and NspA genes of Neisseria gonorrhoeae in mice / 中华皮肤科杂志

Objective To evaluate the immunogenicity of a recombinant adenovirus containing the porin IB (PIB) gene and Neisseria surface protein A (NspA) gene of N.gonorrhoeae in BALB/c mice.Methods A recombinant adenovirus containing the PIB gene and NspA gene of N.gonorrhoeae (pAdEasy-1-PN) was constructed in previous studies.Thirty BALB/c mice were randomly and equally divided into 5 groups:low-,medium-and high-dose experiment group intramuscularly immunized with 104,106,and 108 50％ tissue culture infective dose (TCID50) of the recombinant adenovirus pAdEasy-1-PN,respectively,pAdEasy-1 control group immunized with 106 TCID50 of pAdEasy-1,blank control group immunized with sodium chloride physiological solution.Immunization was carried out twice at a 4-week interval.Serum samples were collected at 0,3 and 5 weeks after the first immunization,and spleens were removed at 5 weeks followed by the isolation of spleen lymphocytes.Enzyme linked immunosorbent assay (ELISA) was performed to determine the serum levels of PIB-specific and NspA-specific antibodies,methyl thiazolyl tetrazolium (MTT) assay to evaluate the proliferaton activity of spleen lymphocytes after stimulation by the recombinant PIB and NspA antigens.A slide agglutination test was used to estimate the anti-bacterial activity of murine serum.The complement-dependent bacteriolytic activity of murine serum was also evaluated.Statistical analysis was carried out by t test.Results Both humoral and cellular immune response specific to PIB and NspA were elicited by the recombinant adenovirus in mice.At 3 and 5 weeks after the immunization,significant differences were observed in the serum levels of PIB-specific (F =285.72,564.83,respectively,both P ＜ 0.01) and NspA-specific (F =521.57,542.61,respectively,both P ＜ 0.01)antibodies.Also,the proliferation index was statistically different among these groups in spleen lymphocytes stimulated with PIB and NspA (F =171.61,233.96,respectively,both P ＜ 0.01).The vaccination efficiency was positively correlated with the inoculation dose of recombinant pAdEasy-1-PN,and 108 TCID50 per dose proved to be the optimal dose for immunization.The sera from mice immunized with pAdEasy-1-PN could agglutinate N.gonorrhoeae and kill it in the presence of complement.Conclusions The recombinant adenovirus pAdEasy-1-PN containing PIB and NspA genes could induce specific humoral and cellular immune response in mice,and may be a potential vaccine against N.gonorrhoeae.

Immune enhancing effects of interleukin 2 genetic adjuvant on DNA vaccine against Chlamydia trachomatis serovar E / 中华皮肤科杂志

ObjectiveTo study the effect of a recombinant plasmid encoding mouse interleukin 2 (mlL-2) on the immunogenicity of DNA vaccine against Chlamydia trachomatis(Ct) serovar E.Methods BALB/c mice were divided into 4 groups to be intramuscularly inoculated with blank plasmid(negative control group),DNA vaccine against Ct serovar E(DNA vaccine group),DNA vaccine against Ct serovar E and a recombinant plasmid containing mIL-2(combination group),and inactivated Ct serovar E elementary bodies (positive control group),respectively.The immunological effects were evaluated by posterior foot pad thickness,proliferation level of spleen lymphocytes,serum level of IL-4 and interferon (IFN)-γ in mice,and the capability to clear Ct genital tract infection.ResultsThe proliferation index of spleen lymphocytes in the combination group and positive control group was similar(3.64 ± 0.41 vs.3.77 ± 0.34),but was significantly different from that in the blank control group and DNA vaccine group (1.37 ± 0.21 and 2.52 ± 0.30).The serum level of IL-4 was(38.49 ± 12.24) pg/ml in the positive control group,significantly higher than in the negative control group,DNA vaccine group and combination group ((25.37 ± 18.93),(24.75 ± 8.49),(21.74 ± 6.43) pg/ml,respectively).With respect to the serum level of IFN-γ,the combination group and positive control group were similar ((1923.3 ± 518.1) pg/ml vs.(2712.5 ± 887.2) pg/ml),but were significantly different from the negative control group and vaccine group((310.8 ± 160.7) pg/ml and(601.3 ± 357.9) pg/ml).Six days after Ct challenge,the exfoliated cells from genital tract were positive for Ct culture in the negative control group,but negative in the other 3 groups.ConclusionIL-2 genetic adjuvant can enhance the immune response,especially Th1 type response,induced by the DNA vaccine against Ct serovar E.

Construction of DNA vaccine with Neisseria gonorrhoeae porin B fused with B subunit of Escherichia coli heat-labile enterotoxin and study on its immune responses in mouse / 中华传染病杂志

Objective To investigate the specific humoral immune response and cellular immune response induced by DNA vaccine with Neisseria gonorrhoeae porin B (PorB) fused with B subunit of Escherichia coli heat-labile enterotoxin B (LTB) in mice. Methods Target genes of porB, ltB and ltB-porB were amplified by polymerase chain reaction (PCR) and cloned into eukaryotic vector pcDNA3.1(-). The recombinants were identified by PCR, enzyme digestion and DNA sequencing.The vectors were transfected into Hela cells, and expressed proteins were checked by cytoimmunofluorescence. Female BALB/c mice were intranasally immunized with recombination vectors. The humoral immune response and cellular immune response were detected by enzyme linked immunosorbent assay (ELISA) and methyl thiazolyl tetrazolium (MTT) colorimetric assay. The expressions of recombination vectors in intranasal mucosal tissues of the immunized mice were detected by immunohistochemistry. The means between groups were compared by analysis of variance. Results All the three recombinants were expressed in Hela cells and intranasal mucosal tissues. The PorB specific IgG in serum and sIgA in vaginal secretions in DNA vaccine immunized mice were significantly higher than those in controls (P＜0.01 ; P＜0.05). Moreover, the sIgA level in pcDNA3.1 (-)/ltB-porB group was higher than that in peDNA3, 1(-)/porB group (P＝0. 002). The levels of interferon-gamma (IFN-γ) and interleukin-4 (IL-4) in the supernatants and stimulation index (SI) of spleen lymphocyte culture in pcDNA3, 1(-)/porB group were (170.04±23.89) pg/mL, (114.68±14.27) pg/mL and 1. 68±0.19, respectively; and those in pcDNA3, 1(-)/ltB-porB group were (161.42±27.50) pg/mL, (124.16±19.04) pg/mL and 1.73±0.28, respectively; which were both higher than those in pcDNA3.1(-)/ phosphate buffered saliae (PBS) group (P＜0. 01; P＜0.05) and pcDNA3.1 (-)/ltB group (all P＜0.05), while there was no significant difference between pcDNA3.1 (-)/ltB-porB group and pcDNA3. 1 (-)/porB group (0. 998, 0. 696, 0. 994; all P＞0.05). Conclusions The constructed DNA vaccines are all successfully expressed in Hela cells and murine intranasal mucosal tissues. The mucosal immunization of the vaccines [pcDNA3. 1 (- )/porB and pcDNA3.1 ( -)/ltBporB] could induce humoral immune response and cellular immune response, especially mucosal immune response. It is confirmed that mucosal adjuvant LTB could promote PorB to induce higher level of mucosal immune response in mice.

Ubiquitin and ESAT6 antigen fusion gene DNA vaccine induced stronger cellular immune response in mice / 第二军医大学学报

Objective: To construct Mycobacterium tuberculosis ESAT6 (pE) antigen DNA vaccine and ubiquitin-ESAT6 fusion gene (pUE) DNA vaccine. Methods: The constructed DNA vaccines were intramuscularly inoculated into female BALB/c mice separately. The serum antibodies (including IgG, IgG1, and IgG2a), Cytokines (IFN-γ and IL-4), and cytotoxic T lymphocytes response were detected in the immunized mice. Results: Mice in pE group had a higher serum level of IgG (P< 0.01) and a lower value of IgG2a /IgG1 ([2.28±0.40] vs [3.87±0.60],P<0.05) than mice in pUE group. Besides, mice in pUE group secreted more IFN-γ than those in pE group (P<0.01), but secreted less IL-4 (P<0.01). Furthermore, pUE enhanced the activity of CTL. The results showed that pUE DNA vaccine induced weaker humoral immune response, but stronger cellular immune responses compared to pE DNA vaccine. Conclusion: The pUE DNA vaccine constructed in this study sheds new lights on the prophylactic and therapy of tuberculosis.

Cellular immune responses induced by DNA vaccine against Chlamydia trachomatis E serotype / 中华皮肤科杂志

Objective To study cellular immune responses induced by DNA vaccine against Chlamydia trachomatis (Ct) serotype E. Methods BALB/c mice were divided into three groups to be intramuscularly immunized by blank plasmid (negative control group), DNA vaccine against Ct serotype E (vaccine group), and inactivated Ct elementary body (positive control group), respectively. Two weeks after the last immunization,delayed-type hypersensitivity (DTH) response was evaluated; MTT assay was performed to detect the proliferation of spleen lymphocytes, ELISA to measure the serum level of interferon-γin mice. Some immunized mice underwent a genital challenge with Ct elementary body followed by isolation of Ct from exfoliated epithelial cells in genital tract and pathological examination of cervical tissue from the challenged mice. Results Compared to negative control group, vaccine group and positive control group experienced a stronger DTH response.The lymphocyte stimulating index and serum level of IFN-γwere highest in the positive control group (3.81 ±0.30, 2891.7 ± 1048.8 μg/L), followed by vaccine group (2.35 ± 0.25, 593.3 ± 342.6 μg/L) and negative control group (1.48 ± 0.15, 309.2 ± 157.9 μg/L), and significant difference was observed between the three groups (P ＜ 0.05 or 0.01 ). After Ct challenge, Ct was isolated from exfoliated epithelial cells and cervical tissue was damaged in the negative control group, while in the other two groups, Ct was undetected and genital tract tissue was intact. Conclusions The DNA vaccine against Ct serotype E could induce Ct-specific cellular immune responses to some extent, and offer a protection against vaginal challenge with Ct.

Determination of antigen-specific CTL induced by the gene vaccine in vitro with MHC pentamer / 中华检验医学杂志

Objective To determine the antigen-specific CTL in PBMC induced by a fusional family-gene vaccine of the immunoglobulin heavy chain variable gene framework region combined with the sequence of cytokine CM-CSF in vitro with MHC pentamer. Methods Peripheral blood samples were collected from two healthy donors and two patients. One was follicular lymphoma and another was hair cell leukemia. PBMC were isolated by density gradient centrifugalization with Ficoll and then subsequently differentiated into immature DCs (imDCs) induced by recombinant human GM-CSF and recombinant human IL-4. Gene gun was used to deliver the plasmids of the gene vaccine or the control plasmids into the imDCs. RT-PCR and ELISA assay were used to detect IgHVl-GM-CSF mRNA and GM-CSF in order to validate the transfection of the vaccine. After adding the cytokine cocktail, the imDCs became mature DCs. Then the mature DCs were co-cultured with lymphocytes from the blood samples for the induction of the antigen-specific CTL. The cultured cells were classified into vaccine group and control group and harvested at different time points of 0 d,7d, 17 d and 24 d after transfection. The subset of CD3+CD8+ T cells was analyzed by FCM assay. Finally, the CTL levels were detected with fluorescently labeled MHC pentamer antibody targeting vaccine epitopes. Results With the induction of cytokines, the imDCs with typical morphology were generated in PBMC. After delivering, the efficient expressions of the vaccine in the imDCs were determined by RT-PCR. And ELISA results also confirmed that GM-CSF was produced at a level of (28 ±6) ng/106 cells of the imDCs loaded with the vaccine, which was significantly different from that of control group (10 ± 3) ng/106 cells (t = 5. 191, P <0.01). FCM assay result showed that the CD3+ CD8+ T cells increased in a stepwise pattern during the culture. For control group, the levels at 0 d,7d, 17d and 24 d were ( 34. 24 ± 2. 72 )% , (46.06 ± 3.08)%, ( 65. 34 ± 4. 26 )% and (73.86 ±4.85 )% , respectively. For vaccine group, the results were (32. 28 ± 2. 08 ) % , (45. 32 ± 3. 81)% , ( 63. 37 ± 4. 21)% and (75. 01 ±3. 20)%. The differences between each time point had statistical significance (F = 176. 966 ,P <0.01) ,but there was no statistical differences between vaccine group and control group ( F = 0.657,P>0.05). The MHC pentamer analysis showed that the DCs loaded with IgHV1-GM-CSF fusional vaccine could efficiently induce the antigen-specific CTL response and the CTL levels increased gradually with the culture time, with the highest level of 4. 36% in the lymphoma blood and 3. 89% in the hair cell leukemia blood. Conclusions MHC pentamer assay could efficiently determine the antigen-specific CTLs response induced by the gene vaccine of family IgHV frame region in vitro. It could be a useful method for monitoring of anti-tumor cell immunity and evaluating of diagnosis and prognosis of the tumors in clinical application.

Adjuvant effect of granulocyte-macrophage colony-stimulating factor coding gene on cellular immunity of Japanese encephalitis virus DNA vaccine / 中华传染病杂志

Objective To study the adjuvant effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) coding gene on cellular immunity induced by Japanese encephalitis (JE) virus DNA vaccine. Methods GM-CSF coding gene was amplified by nested-reverse transcriptase-polymerase chain reaction (RT-PCR) technique from BALB/c murine spleen cells. Recombinant plasmids pJME/GM-CSF and pGM-CSF were constructed by JE virus (JEV) prM-E protein with GM-CSF coding gene or GM-CSF coding gene only, respectively. The plasmids were transfected into China hamster ovary (CHO) cells by Lipofectamine 2000. The coding protein expressions and distributions were detected by immunofluorescence. The BALB/c mice were vaccinated with indicated immunogens with or without GM-CSF gene. The changes of T lymphocyte subsets in the spleen and levels of intracellular cytokines, such as interferon (IFN)-γ and interleukin (IL)-4 of splenic cells from mice immunized with different immunogens were evaluated by flow cytometry. The cytotoxicity T lymphocyte (CTL) activity was assessed by lactate dehydrogenase (LDH). The data were compared by one-factor analysis of variance and least significant difference. Results The constructed recombinant pGM-CSF and pJME/GM-CSF were confirmed by restrict enzyme digestion and DNA sequencing. The expressions of the above proteins were mainly in the cytoplasm and minor on cell membrane. The percentage of CD4+ T lymphocytes in pJME/GM-CSF vaccinated group was (33.90±0.79)%, which was significantly higher than that of in other groups (t values were 9. 818, 6. 804, 6.594, 10.061, 9.380, and 17.675, all P<0.05). The percentages of CD4+T lymphocytes in pJME +pGM-CSF (0) and pJME+pGM-CSF (-3) vaccinated groups were (29.83±0.61)% and (29.70±0.51)%, respectively, which were both higher than that in pJME+pGM-CSF (+3) vaccinated group of (27.69+0.50)% (t=3.466, t=3.255, both P<0.05). The percentages of CD8+ T cells in pJME/GM-CSF and pJME+pGM-CSF vaccinated groups were both higher than that in empty vector (pcDNA 3.1+) group and JE inactivated vaccine vaccinated group (t values were 3.811, 2.627, 10.537, and 3.811, all P<0.05). The CTL activity in pJME/GM-CSF vaccinated group was (51.48±0.10)%, which was higher than those in other groups (t values were 22.868, 13.823, 5.377, 32.287, 34.632, and 53.795, all P<0.05). The IFN-γ/IL-4 ratios in pJME/GM-CSF, pJME+pGM-CSF (0) and pJME + pGM-CSF (-3) vaccinated groups were (19.13±1.36), (12.32±0.82) and (7.05±0.43), respectively, which were higher than those in other groups (P<0.05). Conclusion GM-CSF coding gene could enhance the cellular immune response induced by Japanese encephalitis DNA vaccine.

Increased in vivo immunological potency of HB-110, a novel therapeutic HBV DNA vaccine, by electroporation

Pulse-induced permeabilization of cellular membranes, generally referred to as electroporation (EP), has been used for years as a tool to increase macromolecule uptake in tissues, including nucleic acids, for gene therapeutic applications, and this technique has been shown to result in improved immunogenicity. In this study, we assessed the utility of EP as a tool to improve the efficacy of HB-110, a novel therapeutic DNA vaccine against chronic hepatitis B, now in phase 1 of clinical study in South Korea. The potency of HB-110 in mice was shown to be improved by EP. The rapid onset of antigen expression and higher magnitude of humoral and cellular responses in electric pulse-treated mice revealed that EP may enable a substantial reduction in the dosage of DNA vaccine required to elicit a response similar in magnitude to that achievable via conventional administration. This study also showed that EP-based vaccination at 4-week-intervals elicited a cellular immune response which was about two-fold higher than the response elicited by conventional vaccination at 2-week intervals. These results may provide a rationale to reduce the clinical dose and increase the interval between the doses in the multidose vaccination schedule. Electric pulsing also elicited a more balanced immune response against four antigens expressed by HB-110: S, preS, Core, and Pol.

DNA vaccines for cervical cancer: from bench to bedside

More than 99% of cervical cancers have been associated with human papillomaviruses (HPVs), particularly HPV type 16. The clear association between HPV infection and cervical cancer indicates that HPV serves as an ideal target for development of preventive and therapeutic vaccines. Although the recently licensed preventive HPV vaccine, Gardasil, has been shown to be safe and capable of generating significant protection against specific HPV types, it does not have therapeutic effect against established HPV infections and HPV-associated lesions. Two HPV oncogenic proteins, E6 and E7, are consistently co-expressed in HPV-expressing cervical cancers and are important in the induction and maintenance of cellular transformation. Therefore, immunotherapy targeting E6 and/or E7 proteins may provide an opportunity to prevent and treat HPV-associated cervical malignancies. It has been established that T cell-mediated immunity is one of the most crucial components to defend against HPV infections and HPV-associated lesions. Therefore, effective therapeutic HPV vaccines should generate strong E6/E7-specific T cell-mediated immune responses. DNA vaccines have emerged as an attractive approach for antigen-specific T cell-mediated immunotherapy to combat cancers. Intradermal administration of DNA vaccines via a gene gun represents an efficient way to deliver DNA vaccines into professional antigen-presenting cells in vivo. Professional antigen-presenting cells, such as dendritic cells, are the most effective cells for priming antigen-specific T cells. Using the gene gun delivery system, we tested several DNA vaccines that employ intracellular targeting strategies for enhancing MHC class I and class II presentation of encoded model antigen HPV-16 E7. Furthermore, we have developed a strategy to prolong the life of DCs to enhance DNA vaccine potency. More recently, we have developed a strategy to generate antigen-specific CD4+ T cell immune responses to further enhance DNA vaccine potency. The impressive pre- clinical data generated from our studies have led to several HPV DNA vaccine clinical trials.

The Effects of Intradermal Vaccination with DNA Encoding for the T-cell Receptor on the Induction of Experimental Autoimmune Encephalomyelitis in B10.PL Mice

Intradermal gene administration was found to induce a more profound immune response than direct intramusclular gene injection. We performed intradermal vaccination of B10.PL mice with DNA encoding for the V 8.2 region of the T-cell receptors (TCR). Three weeks later, these mice were immunized with rat myelin basic protein (MBP). Daily mean clinical scores and mortality rate were lower in this group compared with controls. The proliferative responses of lymph node cells to rat MBP were slightly less in the vaccination groups than in the control groups (p<0.05). However, we detected no differences between the two groups with regard to the production of MBP-specific IgG, IgG1, & IgG2a antibodies. The levels of cytokine mRNA expression in the vaccination groups were observed higher than in the control groups without antigen-specific stimulation, but all of cytokine expressions between the vaccination and control groups after antigen-specific stimulation were identical. These results demonstrate that intradermal DNA vaccines encoding for TCR might prove to be useful in the control of autoimmune disease.

The Specific Immune Response Elicited by Recombinant CRT120/HPV6bE7 DNA Vaccine in Mice / 中华皮肤科杂志

Objective To investigate the cellular immune response to the recombinant DNA vaccine CRT120/HPV6bE7 in mice. Methods The recombinant encoding HPV6bE7, linked with CRT120, was constructed in pcDNA3.1 eukaryotic vector with the report gene GFP. The pcDNA3.1-GFP -HPV6bE7 was transfected into B16 cells by a lipofectamine kit. The C57BL/6 mice were vaccinated with recombinant DNA plamids. The T-cell phenotype in the peripheral blood lymphocytes of the immunized mice was measured by flow cytometry. The CTL activity of the lymphocytes from the spleens and lymph nodes, and the levels of IL-2 and IFN-? were analyzed. Results The constructed recombinant plasmid CRT120/HPV6bE7 was analyzed. Positive transfected cell clones were established and could stably express the target gene HPV6bE7. Compared with HPV6bE7, CRT120/HPV6bE7 plasmid enhanced to a greater extent CD8+ T-lymphocyte differentiation, the number of TCR?? T-lymphocytes and the levels of IL-2 and IFN-? (all P

Prophylactic Effects of a HSV-2DNA Vaccine in Guinea Pigs / 中华皮肤科杂志

Objective To observe the prophylactic effects of a HSV-2gD2DNA vaccine in guinea pigs challenged with HSV-2strains.Methods Female guinea pigs were divided into3groups with10each,which was immunized intramuscularly with100?g of pc-gD plasmids(recombinant HSV-2DNA vac-cine),or with pcDNA3blank plasmids,with normal saline as control,respectively.Two booster injections were given on day7and day21.Sera were collected for virus neutralization test on day0,day28,and day56.The animals were challenged with HSV-2strain sav intravaginally,and lesions induced on the external genital skin were scored between day1and day21after challenge.Results The titer of neutralizing anti-body to HSV-2was much higher in the sera from animals immunized by pc-gD plasmids than that from ani-mals immunized by pcDNA3blank plasmids or normal saline.Furthermore,the lesion scores on external genital skin were significantly decreased in pc-gD group than those in other two groups with either primary or recurrent infections.Conclusion The constructed gD2vaccine can efficiently protect guinea pigs from genital infection and reduce recurrent infection induced by latent herpes simplex virus.