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.

Evaluation of Protective Immunity of Peptide Vaccines Composed of a 15-mer N-terminal Matrix Protein 2 and a Helper T-Cell Epitope Derived from Influenza A Virus

The matrix protein 2 of influenza A virus (IFAV) has a relatively conserved ectodomain (M2e) composed of 23 amino acids, and M2e-based vaccines have been suggested to induce broad protective immunity in mice. In this study, we investigated whether N-terminal sequence of M2e (nM2e)-based vaccines with more conserved nM2e could induce influenza viral neutralizing activity. We constructed linear peptide vaccines with an nM2e sequence for PR8 virus (nM2Pr) connected to a probable 17-mer IFAV-derived helper T-cell epitope (ThE: T1, T2, or T3) at its N- or C-terminus. The peptide vaccines induced significant production of nM2e Abs regardless of either type or location of the ThE-epitope in BALB/c mice, while only T3 was effective in C57BL/6 mice. The Abs against nM2Pr-T3 elicited broader binding affinities to the nM2e peptides derived from various IFAVs than those against T3-nM2Pr. In addition, the nM2e-based vaccines efficiently protected the immunized mice from the lethal challenge of PR8 virus. These results suggest that the more conserved nM2e without cysteine will be useful for development of universal peptide vaccines than M2e.

Development of Actinobacillus pleuropneumoniae ApxI, ApxII, and ApxIII-specific ELISA methods for evaluation of vaccine efficiency

Among various vaccines against Actinobacillus pleuropneumoniae, subunit vaccines using recombinant proteins of ApxI, ApxII, and ApxIII as vaccine antigens have shown good efficacy in terms of safety and protection. Therefore, subunit vaccines are being applied worldwide and the development of new subunit vaccines is actively being conducted. To evaluate the efficacy of the subunit vaccines, it is important to measure immune responses to each Apx toxin separately. However, the cross-reactivity of antibodies makes it difficult to measure specific immune reactivity to each toxin. In the present study, specific antigen regions among the toxins were identified and cloned to solve this problem. The antigenicity of each recombinant protein was demonstrated by Western blot. Using the recombinant proteins, we developed enzyme-linked immunosorbent assay (ELISA) methods that can detect specific immune responses to each Apx toxin in laboratory guinea pigs. We suggest that the ELISA method developed in this study can be an important tool in the evaluation of vaccine efficiency and vaccine development.

Effect of T-cell immunoglobulin and mucin domain-3 on TRP-2180-188 peptide-stimulated murine spleen lymphocytes co-cultured with B16F10 murine melanoma cells / 中华皮肤科杂志

Objective To evaluate the effect ofT-cell immunoglobulin and mucin domain-3 (TIM-3) on TRP-2180-188 peptide-stimulated murine spleen lymphocytes co-cultured with B16F10 murine melanoma cells.Methods A recombinant plasmid pFUSE-TIM-3-mIgG2Aae1-Fc2 encoding TIM-3 was constructed.Then,the recombinant plasmid and an empty plasmid pFUSE-mIgG2Aae1-Fc2 were transfected into human 293T epithelial cells followed by 48-hour culture for the preparation of supernatants containing TIM-3 and Ig-tail respectively.C57BL/6 mice were immunized with the TRP-2180-188 peptide vaccine for 4 sessions.One week after the last vaccination,C57BL/6 mice were sacrificed,and spleen lymphocytes were collected and then cultured with the TRP-21180-188 peptide and interleukin-2 (IL-2) for 5 days,with lymphocytes untreated with the TRP-2180-188 peptide or IL-2 serving as the control group.Mitomycin-treated B16F10 murine melanoma cells and TRP-2180-188 peptide-stimulated lymphocytes were co-cultured with the presence of supernatants of 293T cells that had been cultured for 48 hours (blank control group),TIM-3-containing supernatants (TIM-3 group) and Ig-tail-containing supernatants (negative control group) separately.After 24 and 48 hours of co-culture,cell counting kit-8 (CCK-8) assay was performed to estimate the proliferative activity of lymphocytes,enzyme-linked immunosorbent assay (ELISA) to determine the supernatant levels of interferon (INF)-γ and tumor necrosis factor (TNF)-α,flow cytometry to determine the percentage of CD8 + T cells in the co-culture system.Results Enzyme digestion and sequence analysis showed that the TIM-3 gene was successfully inserted into the eukaryotic expression plasmid.After 48-hour culture,TIM-3 and Ig-tail expressions were detected in the supernatants of 293T cells transfected with the recombinant plasmid and empty plasmid respectively.As CCK-8 assay showed,the proliferative activity of lymphocytes was significantly lower in the TIM-3 group than in the blank control group and negative control group after 24-and 48-hour culture (78.06％ ± 6.37％ vs.100.00％ ± 10.42％ and 108.70％ ± 9.90％ at 24 hours,42.93％ ± 5.93％ vs.100.00％ ± 6.24％ and 168.00％ ± 2.98％at 48 hours,all P ＜ 0.05),so was the ratio of cellular proliferative activity at 48 hours to that at 24 hours (all P ＜ 0.05).Compared with the blank control group and negative control group,the TIM-3 group showed significantly decreased supernatant levels of IFN-γ and TNF-α after 24-hour (IFN-γ:192.96 γ 5.05 ng/L vs.216.44 ± 7.85 ng/L and 223.67 ±7.79 ng/L,both P＜ 0.05;TNF-α:58.43 ± 0.26 ng/L vs.26.43 ± 0.01 ng/L and 86.85 ± 1.12 ng/L,both P＜ 0.05) and 48-hour culture (IFN-γ:54.95 ± 0.57 ng/L vs.230.06 ± 4.23 ng/L and 167.24 ± 3.33 ng/L,both P ＜ 0.05;TNF-α:30.23 ±0.26 ng/L vs.26.84 ± 0.20 ng/L and 45.34 ± 0.22 ng/L,both P ＜ 0.05).In addition,the median percentage of CD8+ T cells was significantly increased in the TIM-3 group compared with the blank control group and negative control group after 24-and 48-hour culture (3.30％ vs.0.421％ and 2.22％ at 24 hours,4.06％ vs.0.577％ and 0.691％ at 48 hours,all P＜ 0.05).Conclusion TIM-3 in vitro can suppress the proliferative activity of and secretion of IFN-γand TNF-α by lymphocytes,but increase the percentage of CD8 + T cells in the co-culture system of TRP-2180-188 peptide-stimulated lymphocytes and B16F10 cells.

Effection of immune memory of tuberculosis vaccine on memory T cell in mice / 中国医师杂志

Objective Exploring different strengthening immune strategy on long-term immune memory effects for tuberculosis vaccine lays the theoretical foundation.Methods The fusion protein AMM,adjuvant DDA and BCG-PSN mixed built AMM subunit vaccine.Choose only 50 C57BL/6 mice (SPF),according to the table of random number method was divided into 5 groups and each group 10 only,the experiment 1 group injected mice to phosphate buffer solution (PBS) as control; Experiment 2 mice only injected BCG vaccine (BCG) from early; Experiment 3 mice BCG initial free,in 10 weeks with AMM subunit vaccine strengthen immunity; The four mice from early after BCG,respectively on 8 weeks,10 weeks with AMM subunit vaccine strengthen immune mice one time.Experimental 5 groups of mice after BCG initial free,respectively on 6 weeks,8 weeks,10 weeks with AMM subunit vaccine strengthen immune mice a.28 weeks to remove spleen lymphocytes in mice,add 2.5μg/ml Ag85B stimulus 72 h after collecting spleen cell culture supernatant,with ELISA test Ag85B specificity splenic lymphocyte caused IFN ppar-gamma level.Results Spleen cells by antigen Ag85B stimulation,BCG initial free,AMM subunit vaccine strengthen immune once,twice,three times group and PBS compared all had difference (P ＜0.01 orP ＜0.05) ;BCG initial free-AMM subunit vaccine strengthen immune once,twice,three times group and BCG compared all had difference (P ＜0.01 or P ＜0.05) ; BCG initial free-AMM subunit vaccine strengthen immune once and twice or three times group compared with difference (P ＜0.01 orP ＜0.05) ; Initial free-AMM subunit vaccine strengthen immune two group and three times than group difference was statistically significant (P ＞0.05).Conclusion Mice strong immune strengthened the number is not the more the better,the appropriate number of strengthen the immune to induce the most lasting immunity memory,subunit vaccine strengthen immunization strategy may affect the immune memory is one of the important factors.

Research on the apoptosis of malignant melanoma cell induced by transmembrane form of human blood group A mimotope vaccine / 中国医师杂志

Objective To investigate the apoptotic effect of the transmembrane form vaccine of human blood group A mimotope on malignant melanoma cell line B16. Methods B16 cells were transfected with different recombinant plasmid through Lipofectamine 2000 and incubated with different concentration of monoclonal anti-A antibody at 2.5 μg/ml, 5 μg/ml,10 μg/ml and 20 μg/ml. Apoptosis rate of cells was determined with Annexin Ⅴ/PI double staining by flow cytometry. Results Apoptosis rate to P/F-M-pIRES group B16 cells was 74.74% when anti-A monoclonal antibody concentration was 10 μg/ml; apoptosis rate of plasmids carrying peptide/Fas fusion gene such as P/F-M-pIRES group and P/F-pIRES group were significantly higher than M-pIRES group and pIRES group. The apoptosis rate was statistically significantly different between different recombinated plasmid groups (F＝669.707,P＜0.01). The apoptosis rate was statistically significantly different between different antibody groups (F＝106.596,P＜0.01). The interaction between recombinated plasmid groups and antibody groups was statistically significant (F＝34.806,P＜0.01). Conclusions The transmembrane form vaccine of human blood group A mimotope could induce B16 cell apoptosis in vitro. This vaccine may be a promising candidate for potential malignant melanoma therapy.

Immunological properties of Rv1009 domain from Mycobacterium tuberculosis / 中华检验医学杂志

Objective To investigate the immunological properties of Rv1009 domain. Methods BALB/c mice were immunized with Rv1009 domain three times at 2-week interval. ELISA was used to detect the antiRv1009 domain antibody titer in the sera of immunized mice sera. The spleen lymphocytes of the immunized mice were separated and the stimulation index (SI) was measured by MTT colorimetry. Levels of secreted IFN-γ, IL-10 and IL-12 upon specific antigen stimulation were detected by ELISA. The BALB/c mice immunized with Rv1009 domain were intravenously infected with MTB H37Rv. Four weeks after the final injection, the number of CFU in spleens was determined. Results The titer of the specific antibody in sera of the immunized BALB/c mice was 1:12 800. The SI of Rv1009 domain immunized group (2. 40±0. 18) was significantly higher than that of saline immunized group (0.90±0.21). The IFN-γ,IL-10 and IL-12 levels in culture supematant of spleen lymphecytes from the fusion proteins immunized mice was (1 432±30) ng/L, (503±11) ng/L and (311±11) ng/L respectively, significant different from that of saline immunized group[(256±20) ng/L, (76±6) ng/L and(56±8) ng/L,P<0.01]. Four weeks after the final injection,compared with normal saline immunized mice (6.64±0.13), dramatic reduction in MTB replication was observed in the spleen (4.86±0.14) from BALB/c mice immunized with fusion proteins following a subsequent MTB H37Rv challenge, but the protection efficacy of mice immunized with Rv1009 domain was not as good as that of BCG vaccination group (3.81±0.16). Conclusion Rv1009 domain can be used as a candidate for the new TB vaccine.

Cell-penetrating effects of HPV16E7_(49-57) epitope modified by peptide HIV-Tat_(49-57) / 中华皮肤科杂志

Objective To investigate the effects of the intracellular delivery of HPV16E7_(49-57) epi- tope modified by cell-penetrating peptide HIV-Tat_(49-57) and its influential factors.Methods The unique HLA-A2+/H-2kb+ limited CTL epitope of HPV16E7 fused with a cell-penetrating sequence (HIV-Tat_(49-57)) was designed and a 18-mer peptide was synthesized with aid of polypeptide solid phase synthesis technique. The intracellular transport capabilities of these peptides were tested with indirect immunofluorescence assay and laser confocal microscopy.In addition,the CTL epitope and 18-met peptide were used to stimulate PBMC of healthy C57BL/6 mice,and the E7_(49-57) specific CTL responses were measured by LDH cytotoxicity detection kit in PBMC of those mice.Results The HIV-Tat_(49-57) peptide could efficiently assist HPV 16E7_(49-57) peptide in penetrating into BHK cells in a time and dose-dependent manner (P＜0.05).Further- more,the specific CTL activity induced by the 18-mer peptide was much stronger than that induced by the single epitope.Conclusion The results show that HIV-Tat_(49-57) can efficiently deliver the exogenous anti- genic peptide into the cytoplasm of live cells,and induce specific CTL response.This is a new way to de- sign peptide-based vaccine of HPV.