La batalla decisiva contra la fiebre tifoidea en Santiago de Chile en el siglo XX

Hasta 1983, cuando alcanzaba la increíble tasa de 118 casos por 100.000 habitantes, la fiebre tifoidea era la peor amenaza infecciosa en Santiago, Chile, ciudad que figuraba junto a Ciudad de México, El Cairo y Bombay, como una de las con mayor endemia en el mundo. El Ministerio de Salud respondió formando el Comité de Tifoidea de Chile, con participación de expertos nacionales y del grupo de Myron Levine, de la Universidad de Maryland, que llevó a cabo ingeniosas investigaciones, culpando al río Mapocho, cuyas aguas contaminadas con Salmonella typhi regaban los predios agrícolas vecinos, conformando así un ciclo largo de infección. Las vacunas antitíficas ensayadas (oral Ty21a atenuada y polisacárido capsular Vi inyectable) no mostraron eficacia, los portadores crónicos no se trataron, pero una campaña sanitaria a través de la televisión contribuyó decisivamente a mejorar los hábitos higiénicos de la población, fortalecida por el pánico que causó la llegada del cólera en 1991, y la fiebre tifoidea prácticamente desapareció del escenario.

Until 1983, when reached the incredible frequency of 118 cases for 100.000 habitants, typhoid fever was the worst infectious threat in Santiago, Chile, city that appeared next to Mexico City, Cairo and Bombay, as one of the most endemic in the world. The Ministry of Health responded with the creation of The Chilean Typhoid Committee, with the participation of national experts and Myron Levine's group, which carried out ingenious investigations blaming the Mapocho River, whose waters contaminated with Salmonella typhi irrigated the neighboring farms, thus conforming a long cycle of infection. Typhoid vaccines tested (strain Ty 21a oral and Vi capsular polysaccharide) did not show efficacy, chronic carriers were not treated, but a health campaign on television made a decisive contribution to improving hygiene habits of the population, strengthened by the panic caused by the arrival of cholera in 1991, and typhoid fever practically disappeared from the stage.

Advances in the application of yeast surface display technology / 生物工程学报

Yeast surface display (YSD) is a technology that fuses the exogenous target protein gene sequence with a specific vector gene sequence, followed by introduction into yeast cells. Subsequently, the target protein is expressed and localized on the yeast cell surface by using the intracellular protein transport mechanism of yeast cells, whereas the most widely used YSD system is the α-agglutinin expression system. Yeast cells possess the eukaryotic post-translational modification mechanism, which helps the target protein fold correctly. This mechanism could be used to display various eukaryotic proteins, including antibodies, receptors, enzymes, and antigenic peptides. YSD has become a powerful protein engineering tool in biotechnology and biomedicine, and has been used to improve a broad range of protein properties including affinity, specificity, enzymatic function, and stability. This review summarized recent advances in the application of YSD technology from the aspects of library construction and screening, antibody engineering, protein engineering, enzyme engineering and vaccine development.

Oral and nasal vaccination: current prospects, challenges, and impact of nanotechnology-based delivery systems

Abstract Currently, mucosal vaccine administration has stood out as an easier and non-invasive application method. It can also be used to induce local and systemic immune responses. In the COVID-19 pandemic context, nasal and oral vaccines have been developed based on different technological platforms. This review addressed relevant aspects of mucosal vaccine administration, with emphasis on oral and nasal vaccinations, in addition to the importance of using nanotechnology-based delivery systems to enable these strategies.

Therapeutic effect of oral vaccine based on glutamate decarboxylase 65 on streptozotocin-induced type 1 diabetic mice / 中国药科大学学报

@#To investigate the therapeutic effect of oral vaccine based on glutamate decarboxylase 65 (GAD65) on streptozotocin (STZ) -induced type 1 diabetic (T1D) mice, the mice model of T1D was established by intraperitoneal injection of low dose multiple STZ. CTB-GADIII encapsulated with calcium alginate (Ca-Alg-GADIII) was formulated using crosslinking technology with sodium alginate and calcium chloride, and was administered intragastric to T1D mice once a week for 5 consecutive weeks.Blood glucose and body weight of the mice were recorded weekly, and pharmacodynamics against T1D of Ca-Alg-GADIII were investigated by glucose tolerance assay (OGTT) and pancreatic histopathological analysis. The levels of glutamic acid decarboxylase antibody (GADA), and insulin autoantibody (IAA) and related cytokines (IL-4, IFN-γ, TGF-β1) in serum were detected by ELISA, and the CD4 + T cell subsets were detected by flow cytometry. The immunological mechanism of oral vaccine against T1D was preliminarily discussed. The results showed that the disease-related indicators improved in immunized mice: fasting blood glucose improved, glucose tolerance and insulin secretion increased, pancreatic injury decreased, autoantibodies like GADA and IAA titers significantly decreased, and CD4 + T cell immune balance in mesenteric lymph node (MLN) and pancreatic lymph node (PLN) improved to some extent. The results suggest that oral vaccine Ca-Alg-GADIII has some therapeutic effect on STZ-induced T1D mice.

An oral Aujeszky's disease vaccine (YS-400) induces neutralizing antibody in pigs

PURPOSE: Aujeszky's disease (AD) is an economically important disease affecting both wild and domestic pigs of the species Sus scrofa. A previous study yielded serological evidence of AD in Korean wild boars, which could spread AD to other animals. A new Aujeszky's disease virus (ADV) bait vaccine is required to prevent AD outbreaks in swine. In the present study, we investigated the safety and immunogenicity of a gE-deleted marker vaccine, strain YS-400, in young domestic pigs. MATERIALS AND METHODS: The YS-400 strain was propagated in Vero cells, and the trial ADV bait vaccine (a vaccine blister in a matrix including an attractant) was prepared. Pigs were orally immunized with the vaccine (2 mL, 10(7.5) TCID(50)/mL) delivered using a syringe or in the bait vaccine. The animals were observed for 9 weeks after vaccination, and immunogenicity was assessed using a virus neutralization (VN) test and enzyme linked immunosorbent assay. RESULTS: The YS-400 strain was non-pathogenic to pigs when given orally and induced high VN titers (1:32-1:128) 6 weeks post-administration. Of the pigs given the ADV bait vaccine twice or three times, 40% were seropositive by 2 weeks, and 100% were seropositive by 7 weeks after the first dose. Pigs that consumed the AD bait vaccine three times developed VN titers that were slightly higher than those of pigs given the vaccine twice. CONCLUSION: Domestic pigs given the trial ADV bait vaccine exhibited no adverse effects and developed high VN titers against ADV, indicating that the YS-400 strain is safe and can prevent ADV infection in domestic pigs.

Pattern of cytokine and chemokine production by THP-1 derived macrophages in response to live or heat-killed Mycobacterium bovis bacillus Calmette-Guérin Moreau strain

Tuberculosis has great public health impact with high rates of mortality and the only prophylactic measure for it is the Mycobacterium bovisbacillus Calmette-Guérin (BCG) vaccine. The present study evaluated the release of cytokines [interleukin (IL)-1, tumour necrosis factor and IL-6] and chemokines [macrophage inflammatory protein (MIP)-1α and MIP-1β] by THP-1 derived macrophages infected with BCG vaccine obtained by growing mycobacteria in Viscondessa de Moraes Institute medium medium (oral) or Sauton medium (intradermic) to compare the effects of live and heat-killed (HK) mycobacteria. Because BCG has been reported to lose viability during the lyophilisation process and during storage, we examined whether exposing BCG to different temperatures also triggers differences in the expression of some important cytokines and chemokines of the immune response. Interestingly, we observed that HK mycobacteria stimulated cytokine and chemokine production in a different pattern from that observed with live mycobacteria.

Advance in oral vaccine / 中国药学杂志

Oral vaccine can stimulate the immunity of intestinal mucosa effectively after entering the gastrointestinal orally. It is a more ideal way of immunity compared with the traditional injection vaccine, since oral vaccine delivery mode is simple and quick while the results of immunity is stable and durable. There are many types of oral vaccines, including live attenuated vaccine, DNA vaccine and transgenic plant vaccine. Oral vaccine vehicle has more types, which not only can enhance the body to absorb the antigen but also can enhance the immune effect of the protective antigen effectively. In this paper, the mechanism about immunologic effect and recent advance on the research progression of oral vaccine are reviewed, what would provide ideas for related basic research.

Strategic model of national rabies control in Korea

Rabies is an important zoonosis in the public and veterinary healthy arenas. This article provides information on the situation of current rabies outbreak, analyzes the current national rabies control system, reviews the weaknesses of the national rabies control strategy, and identifies an appropriate solution to manage the current situation. Current rabies outbreak was shown to be present from rural areas to urban regions. Moreover, the situation worldwide demonstrates that each nation struggles to prevent or control rabies. Proper application and execution of the rabies control program require the overcoming of existing weaknesses. Bait vaccines and other complex programs are suggested to prevent rabies transmission or infection. Acceleration of the rabies control strategy also requires supplementation of current policy and of public information. In addition, these prevention strategies should be executed over a mid- to long-term period to control rabies.

Immune response after rabies oral immunization in mice

The objective of this study was to formulate an anti-rabies oral vaccine from the cell culture vaccine PV TECPAR to elicit the production of antibodies against the rabies in mice. A vaccine was developed using 10(7.5) DL50/0.03 ml viral antigens homogenised in lanovaseline to facilitate oral administration. Mice were vaccinated two times for seroconversion. Sera of the vaccinated mice showed a higher level of antibody production than the control group. These results could be used to direct the development of an anti-rabies oral vaccine.

Ginsan Enhances Humoral Antibody Response to Orally Delivered Antigen

BACKGROUND: There have been several reports describing the capability of ginseng extracts as an adjuvant. In this study, we tested if ginsan, a polysaccharide extracted from Panax ginseng, was effective in enhancing antibody response to orally delivered Salmonella antigen. METHODS: Ginsan was treated before oral salmonella antigen administration. Salmonella specific antibody was determined by ELISA. mRNA expression was determined by RT-PCR. Cell migration was determined by confocal microscopy and flow cytometry. COX expression was detected by western blot. RESULTS: Ginsan treatment before oral Salmonella antigen delivery significantly increased both secretory and serum antibody production. Ginsan increased the expression of COX in the Peyer's patches. Various genes were screened and we found that CCL3 mRNA expression was increased in the Peyer's patch. Ginsan increased dendritic cells in the Peyer's patch and newly migrated dendritic cells were mostly found in the subepithelial dome region. When COX inhibitors were treated, the expression of CCL3 was reduced. COX inhibitor also antagonized both the migration of dendritic cells and the humoral immune response against oral Salmonella antigen. CONCLUSION: Ginsan effectively enhances the humoral immune response to orally delivered antigen, mediated by CCL3 via COX. Ginsan may serve as a potent vaccine suppliment for oral immunization.

A predictive model for the level of sIgA based on IgG levels following the oral administration of antigens expressed in Sacchromyces cerevisiae

Oral vaccination may be the most efficient way of inducing an immune response at the remote mucosal site through the common mucosal immune network. Antigenspecific secretory IgA (sIgA) is the major immunoglobulin type generally detected in the secretions of experimental animals following an effective oral immunization. Actinobacillus pleuropneumoniae causing disease in the lung of pig initially interacts, colonizes, and infects the host tissues at the mucosal surface of the respiratory tract. Also, importantly for A. pleuropneumoniae protection, the quantity of sIgA in the lung had merits associated with the mucosal immunity. However, there is no simple method to monitor the level of sIgA as an indicator for the induction of local immune responses by an oral vaccination in the target tissue. Therefore, the relationship between sIgA and IgG was analyzed to evaluate the induction of local immune responses by an oral immunization with Saccharomyces cerevisiae expressing the apxIA and apxIIA genes of A. pleuropneumoniae in this study. The correlation coefficient of determination (r2 x 100) for paired samples in both vaccinated and control groups showed a significant positive-relationship between IgG in sera and sIgA in the lung or intestine. These results indicated that IgG antibody titers in sera could be useful to indirectly predict local immune response, and sIgA, in the lung or intestine to evaluate the efficacy of an oral vaccination.

Preparation of Oral Vaccine Microspheres for Newcastle Disease Virus / 中国药房

OBJECTIVE:To study the preparation technique for oral vaccine microspheres.METHODS:Newcastle dis-ease virus(NDV)vaccine was used as model drug,and PLGA as carrying agent to prepare NDV-PLGA oral microspheres by W/O/W emulsifying-solvent evaporation technique.Orthogonal design experiment was carried out to determine the influence of NDV volume,PLGA concentration,stirring speed and protectants at inner aqueous phase on the shape,size,adhesion and activity of microspheres.The valence of drug release in microspheres was measured by hemagglutination.RESULTS:The best condition for preparing NDV microspheres was found to be200?l of NDV,4%PLGA,stirring speed at8000r/min,and BSA as protectant.CONCLUSION:The established technique is the optimal choice for preparation of oral vaccine micro-spheres.

Preparation and immunologenicity study of HpaA-CtxB fusion protein to Helicobacter pylori in mice / 中国免疫学杂志

Objective:To explore the immune response in mice fed orally with the conjugated antigen of HpaA-CtxB(HCTB).Methods:A recombinant strain which could express bivalent antigen of HpaA and CtxB subunit was constructed. HpaA and CtxB gene was amplified by PCR. The DNA products of HpaA and CtxB were inserted into a prokaryotic expression vector pQE-30 respectively, and then translated into E.coli strain DH5? to express HCTB fusion protein. Its immunogenicity was analyzed by Western blot. After purification, to fed mice by oral immunization. The change of antigen-specific ASC antibody(IgG and IgA) in the mucosa of the animals were detected by ELISPOT and ELISA assay. Results:HCTB fusion gene was sequenced as 1 161 bp, the fusion protein encoded polypeptides of 387 amino acid residues.The molecular weight was 40 kD analysed by SDS-PAGE. The level of soluble expression product was about 41.67% of total cell protein. After affinity chromatography, the purity of fusion protein was above 92%.Western blot analysis confirmed that fusion protein could be specifically recognized by the serum of anti-HpaA and anti-CT. Antigen-specific ASC and antibody response in animals immunized with HCTB or HpaA was determined by ELISPOT and ELISA. The results showed that the number of sIgA and IgG-ASC increased significantly in PP and gastric mucosa, especially those of the sIgA-ASC by orally immunization with HCTB. The levels of specific antibody were also higher than those of controls. Conclusion:The results indicated that the oral immunization with HCTB induces effective mucosal immune respones and produced higher levels sIgA. The recombinant fusion protein HCTB can be used as an effective oral vaccine for prevention and treatment of infection of Hp.