Evaluation of attenuated Salmonella choleraesuis-mediated inhibin recombinant DNA vaccine in rats.

DNA vaccination has been studied intensively as a potential vaccine technology. We evaluated the effect of an attenuated Salmonella choleraesuis-mediated inhibin DNA vaccine in rats. First, 15 rats were treated with different doses of an inhibin vaccine to evaluate vaccine safety. Next, 30 rats were divided into 3 groups and injected intramuscularly with the inhibin vaccine two (T1) or three times (T2) or with control bacteria (Con) at 4-week intervals. The inhibin antibody levels increased [positive/negative well (P/N) value: T1 vs Con = 2.39 ± 0.01 vs 1.08 ± 0.1; T2 vs Con = 2.36 ± 0.1 vs 1.08 ± 0.1, P < 0.05] at week 2 and were maintained at a high level in T1 and T2 until week 8, although a small decrease in T2 was observed at week 10. Rats in the T1 group showed more corpora lutea compared with the Con group (10.50 ± 0.87 vs 7.4 ± 0.51, P < 0.05). Estradiol (0.439 ± 0.052 vs 0.719 ± 0.063 ng/mL, P < 0.05) and progesterone (1.315 ± 0.2 vs 0.737 ± 0.11 ng/mL, P < 0.05) levels differed significantly at metestrus after week 10 between rats in the T1 and Con groups. However, there were no significant differences in body, ovary, uterus weights, or pathological signs in the ovaries after immunization, indicating that this vaccine is safe. In conclusion, the attenuated S. choleraesuis-mediated inhibin vaccine may be an alternative to naked inhibin plasmids for stimulating ovarian follicular development to increase the ovulation rate in rats.

HCV-specific immune responses induced by CIGB-230 in combination with IFN-α plus ribavirin.

AIM: To analyze hepatitis C virus (HCV)-specific immune responses in chronically infected patients under triple therapy with interferon-α (IFN-α) plus ribavirin and CIGB-230. METHODS: CIGB-230 was administered in different schedules with respect to IFN-α plus ribavirin therapy. Paired serum and peripheral blood mononuclear cells (PBMC) samples from baseline and end of treatment were analyzed. The HCV-specific humoral response was tested by enzyme-linked immunosorbent assay, neutralizing antibodies were evaluated by cell culture HCV neutralization assays, PBMC proliferation was assayed by carboxyfluorescein succinimidyl ester staining and IFN-γ secretion was assessed by enzyme-linked immunospot. Data on virological and histological response and their association with immune variables are also provided. RESULTS: From week 12 to week 48, all groups of patients showed a significant reduction in mean leukocyte counts. Statistically significant reductions in antibody titers were frequent, but only individuals immunized with CIGB-230 as early add-on treatment sustained the core-IgG response, and the neutralizing antibody response was enhanced only in patients receiving CIGB-230. Cell-mediated immune responses also tended to decline, but significant reductions in IFN-γ secretion and total absence of core-specific lymphoproliferation were exclusive of the control group. Only CIGB-230-immunized individuals showed de novo induced lymphoproliferative responses against the structural antigens. Importantly, it was demonstrated that the quality of the CIGB-230-induced immune response depended on the number of doses and timing of administration in relation to the antiviral therapy. Specifically, the administration of 6 doses of CIGB-230 as late add-on to therapy increased the neutralizing antibody activity and the de novo core-specific IFN-γ secretion, both of which were associated with the sustained virological response. CONCLUSION: CIGB-230, combined with IFN-α-based therapy, modifies the immune response in chronic patients. The study provides evidence for the design of more effective therapeutic vaccine interventions against HCV.

BHT-3009, a myelin basic protein-encoding plasmid for the treatment of multiple sclerosis.

Even though the etiology of multiple sclerosis (MS) remains largely unknown, research data support the hypothesis that autoimmunity plays a major role in disease development. Several disease-modifying agents have been approved for the treatment of MS; however, there is still a need for antigen-specific treatments that combine efficacy and safety. DNA vaccination represents a new therapeutic alternative in this respect. Preclinical studies in different models of autoimmunity have demonstrated that injection of plasmid DNA encoding a self-antigen in mice restores self-tolerance, leaving immunity against infectious and tumor antigens intact. Based on this evidence, the first DNA vaccine for MS has been created. Bayhill Therapeutic Inc's BHT-3009 encodes full-length, human myelin basic protein (MBP), and has recently been evaluated in a phase I/II and a phase II clinical trial. BHT-3009 was safe and well tolerated in both trials, inducing immune tolerance that extended beyond MBP to other myelin antigens. In addition, a reduction in the number of active lesions was observed, which was accompanied by a decrease in clinical relapse rates, particularly in patients with high immunological activity at baseline. BHT-3009 appears to be a promising new approach for the treatment of MS, although further clinical trials are warranted to confirm the early findings.

Development and evaluation of a recombinant DNA vaccine candidate expressing porcine circovirus 2 structural protein: [revision] / Desenvolvimento e avaliação de um candidato à vacina de DNA recombinante expressando a proteína estrutural do circovírus suíno: [revisão]

Porcine circovirus 2 (PCV2) is generally associated with the porcine circovirosis syndrome, which is considered an important disease of swine and has potentially serious economic impact on the swine industry worldwide. This article describes the construction of a recombinant plasmid expressing the PCV2 structural protein and the evaluation of cellular and humoral immune responses produced by this recombinant vaccine in BALB/c mice. The vaccine candidate was obtained and analyzed in vivo, in an effort to determine the ability to induce a specific immune response in mice. DNA was extracted from a Brazilian PCV2 isolate and the gene coding for Cap protein was amplified by PCR and inserted into an expression plasmid. Groups of BALB/c mice were inoculated intra-muscularly and intradermally in a 15-day interval, with 100 µg and 50 µg of the vaccine construct, respectively. Another group was inoculated intramuscularly with 100 µg of empty plasmid, corresponding to the control group. Seroconversion and cellular response in BALB/c mice were compared and used for vaccine evaluation. Seroconversion was analyzed by ELISA. After a series of 3 immunizations the spleen cells of the immunized animals were used to perform lymphocyte proliferation assays. Seroconversion to PCV2 was detected by ELISA in the animals inoculated with the vaccine construct when compared with control groups. Lymphocyte proliferation assays showed a stronger cell proliferation in the inoculated animals compared with the control group. Thus, the vaccine candidate construct demonstrated to be able to induce both humoral and cellular responses in inoculated mice.

O circovírus suíno 2 (PCV2) é geralmente associado à síndrome da circovirose suína, que é considerada uma importante doença de suínos e possui um sério impacto econômico na suinocultura mundial. Este trabalho descreve a construção de um plasmídeo recombinante que expressa a proteína estrutural do PCV2 e a avaliação das respostas imune humoral e celular por meio de vacinação em camundongos BALB/c. O candidato vacinal foi submetido a análises in vivo, determinando a capacidade de induzir resposta imune específica em camundongos. O DNA de um isolado brasileiro de PCV2 foi extraído e o gene que codifica para a proteína do capsídeo foi amplificado por PCR e inserido num plasmídeo de expressão. Grupos de camundongos BALB/c foram inoculados por via intramuscular e intradérmica a cada 15 dias, com 100µg e 50µg da construção vacinal, respectivamente. Outro grupo foi inoculado com 100µg do plasmídeo original, correspondente ao grupo controle. A soroconversão e a resposta celular dos grupos de camundongos BALB/c vacinados foram comparados como parâmetros de avaliação vacinal. A soroconversão foi avaliada por um teste de ELISA. Após 3 imunizações, as células esplênicas dos animais imunizados foram utilizadas nos ensaios de linfoproliferação. A soroconversão para o PCV2 foi detectada por ELISA nos animais inoculados com a construção vacinal quando comparados com o grupo controle. Nos ensaios de linfoproliferação foi observada uma grande proliferação celular nos animais inoculados comparados ao grupo controle. Portanto, o candidato vacinal demonstrou ser capaz de induzir tanto uma resposta humoral e celular nos camundongos inoculados.

Development and evaluation of a recombinant DNA vaccine candidate expressing porcine circovirus 2 structural protein: [revision] / Desenvolvimento e avaliação de um candidato à vacina de DNA recombinante expressando a proteína estrutural do circovírus suíno: [revisão]

Porcine circovirus 2 (PCV2) is generally associated with the porcine circovirosis syndrome, which is considered an important disease of swine and has potentially serious economic impact on the swine industry worldwide. This article describes the construction of a recombinant plasmid expressing the PCV2 structural protein and the evaluation of cellular and humoral immune responses produced by this recombinant vaccine in BALB/c mice. The vaccine candidate was obtained and analyzed in vivo, in an effort to determine the ability to induce a specific immune response in mice. DNA was extracted from a Brazilian PCV2 isolate and the gene coding for Cap protein was amplified by PCR and inserted into an expression plasmid. Groups of BALB/c mice were inoculated intra-muscularly and intradermally in a 15-day interval, with 100 µg and 50 µg of the vaccine construct, respectively. Another group was inoculated intramuscularly with 100 µg of empty plasmid, corresponding to the control group. Seroconversion and cellular response in BALB/c mice were compared and used for vaccine evaluation. Seroconversion was analyzed by ELISA. After a series of 3 immunizations the spleen cells of the immunized animals were used to perform lymphocyte proliferation assays. Seroconversion to PCV2 was detected by ELISA in the animals inoculated with the vaccine construct when compared with control groups. Lymphocyte proliferation assays showed a stronger cell proliferation in the inoculated animals compared with the control group. Thus, the vaccine candidate construct demonstrated to be able to induce both humoral and cellular responses in inoculated mice.(AU)

O circovírus suíno 2 (PCV2) é geralmente associado à síndrome da circovirose suína, que é considerada uma importante doença de suínos e possui um sério impacto econômico na suinocultura mundial. Este trabalho descreve a construção de um plasmídeo recombinante que expressa a proteína estrutural do PCV2 e a avaliação das respostas imune humoral e celular por meio de vacinação em camundongos BALB/c. O candidato vacinal foi submetido a análises in vivo, determinando a capacidade de induzir resposta imune específica em camundongos. O DNA de um isolado brasileiro de PCV2 foi extraído e o gene que codifica para a proteína do capsídeo foi amplificado por PCR e inserido num plasmídeo de expressão. Grupos de camundongos BALB/c foram inoculados por via intramuscular e intradérmica a cada 15 dias, com 100µg e 50µg da construção vacinal, respectivamente. Outro grupo foi inoculado com 100µg do plasmídeo original, correspondente ao grupo controle. A soroconversão e a resposta celular dos grupos de camundongos BALB/c vacinados foram comparados como parâmetros de avaliação vacinal. A soroconversão foi avaliada por um teste de ELISA. Após 3 imunizações, as células esplênicas dos animais imunizados foram utilizadas nos ensaios de linfoproliferação. A soroconversão para o PCV2 foi detectada por ELISA nos animais inoculados com a construção vacinal quando comparados com o grupo controle. Nos ensaios de linfoproliferação foi observada uma grande proliferação celular nos animais inoculados comparados ao grupo controle. Portanto, o candidato vacinal demonstrou ser capaz de induzir tanto uma resposta humoral e celular nos camundongos inoculados.(AU)

New types of immunotherapy in children.

Injection immunotherapy has been shown to be particularly beneficial in treating allergic rhinitis, mild to moderate asthma, and anaphylaxis caused by bee and wasp venom. It also produces a long-term, antigen-specific, protective immune effect and is the only treatment that offers the possibility of reducing the risk of asthma development in children with allergic rhinitis. Nonetheless, the potentially severe side effects associated with this form of immunotherapy limit its widespread use. Diverse preparations are being developed to increase its safety and improve its efficacy. These include alternative routes of administration, particularly the sublingual route; use of novel adjuvants, such as CpG oligonucleotides and mycobacterial vaccines; and other approaches, such as peptide immunotherapy, recombinant allergens, DNA vaccination, and combined therapy. Some of these immunotherapy forms have been evaluated in children.

Evaluación de la protección de los trabajadores de un hospital del IPSS con vacuna DNA recombinante contra el virus de la hepatitis B / Evaluation of the protection of the workers hospital IPSS with recombinant DNA vaccine against hepatitis B virus

Se realiza la titulación e anticuerpos contra el antígeno de superficie del virus de hepatitis B en un grupo de trabajadores del Hospital G. Almenara I. del Instituto Peruano de Seguridad Social, para valorara la respuesta inmunológica a la vacuna recombinante contra la hepatitis viral B. La decisión de proteger a los trabajadores del hospital de una posible contaminación con el virus de la hepatitis B se fundamenta en la alta prevalencia de marcadores virales corroborada en una investigación previa en 62 empleados de esta institución. De 2,418 trabajdores que fueron vacunados con Euvax B, se seleccionaron 337 (190 mujeres y 147 hombres). Todos recibieron tres dosis de la vacuna DNA recombinante con el esquema 0,1,2. La titulación se realizó 21 días después de recibida la tercera dosis. La edad promedio fue de 36.5 años. Los resultados fueron: 336 (99.7 por ciento) seroconvirtieron. Se obtuvo seroprotección en 322 (95.5 por ciento), quedando desprotegidos 14 (4.2 por ciento), uno de los cuales no seroconvirtió (0.3 por ciento). El 100 por ciento de las mujeres fueron seroprotegidas, siendo la media de las menores de 40 años mayor que la de las mayores de 40 y en los varones hubo mayor número de seroprotegidos entre los menores de 40 años. El paciente que no seroconvirtió fue mayor de 40 años. La media de los valores de titulación fue mayor en las mujeres. Se concluye que la vacuna evaluada fue inmunogénicamente afectiva, en títulos algo superiores a los reportados por la literatura y que la mejor respuesta se obtuvo en las mujeres menores de 40 años.

[The reactogenicity of Heberbiovac-HB vaccine at different doses]. / Reactogenicidad de la vacuna Heberbiovac-HB a diferentes dosis.

Reactogenicity was measured after applying the Heberbiovac-HB recombinant vaccine against hepatitis B virus to three groups of children aged 6-9 years. The vaccine was derived from yeast cells, administered at doses of 10, 5, and 2.5 g, with a schedule of 0, 1 and 6 months. The overall observed symptomatology was low (12.2%) in the three groups with 10.7%, 13.5%, and 12.3% for 10, 5, and 2.5 g, respectively. The predominant symptoms and signs were febricula (7.0%), local pain (3.1%), and erythema (1.2%). No significant differences were found when making a comparison between groups and sexes. An acceptable reactogenicity of the immunogen was confirmed, thus its use is recommended for the protection against hepatitis B virus.