RESUMO
The development of molecules specific for M. tuberculosis-infected cells has important implications, as these tools may facilitate understanding of the mechanisms regulating host pathogen interactions in vivo. In addition, development of new tools capable to targeting M. tuberculosis-infected cells may have potential applications to diagnosis, treatment, and prevention of tuberculosis (TB). Due to the lack of CD1b polymorphism, M. tuberculosis lipid-CD1b complexes could be considered as universal tuberculosis infection markers. The aim of the present study was to display on the PIII surface protein of m13 phage, a human αß single-chain T-cell receptor molecule specific for CD1b:2-stearoyl-3-hydroxyphthioceranoyl-2´-sulfate-α-α´-D-trehalose (Ac2SGL) which is a complex presented by human cells infected with M. tuberculosis. The results showed the pIII fusion particle was successfully displayed on the phage surface. The study of the recognition of the recombinant phage in ELISA and immunohistochemistry showed the recognition of CD1b:Ac2SGL complexes and cells in human lung tissue from a tuberculosis patient respectively, suggesting the specific recognition of the lipid-CD1b complex.
Assuntos
Antígenos de Bactérias/imunologia , Antígenos CD1/imunologia , Técnicas de Visualização da Superfície Celular , Glicolipídeos/imunologia , Mycobacterium tuberculosis/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Tuberculose/imunologia , Bacteriófago M13 , Linhagem Celular , Genes Codificadores da Cadeia alfa de Receptores de Linfócitos T , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T , Humanos , Pulmão/imunologia , Pulmão/microbiologia , Ativação Linfocitária , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas ViraisRESUMO
A vaccine candidate against cholera was developed in the form of oral tablets to avoid difficulties during application exhibited by current whole cell inactivated cholera vaccines. In this study, enteric-coated tablets were used to improve the protection of the active compound from gastric acidity. Tablets containing heat-killed whole cells of Vibrio cholerae strain C7258 as the active pharmaceutical compound was enteric-coated with the polymer Kollicoat(®) MAE-100P, which protected them efficiently from acidity when a disintegration test was carried out. Enzyme-linked immunosorbent assay (ELISA) anti-lipopolysaccharide (LPS) inhibition test and Western blot assay revealed the presence of V. cholerae antigens as LPS, mannose-sensitive haemagglutinin (MSHA) and outer membrane protein U (Omp U) in enteric-coated tablets. Immunogenicity studies (ELISA and vibriocidal test) carried out by intraduodenal administration in rabbits showed that the coating process of tablets did not affect the immunogenicity of V. cholerae-inactivated cells. In addition, no differences were observed in the immune response elicited by enteric-coated or uncoated tablets, particularly because the animal model and immunization route used did not allow discriminating between acid resistances of both tablets formulations in vivo. Clinical studies with volunteers will be required to elucidate this aspect, but the results suggest the possibility of using enteric-coated tablets as a final pharmaceutical product for a cholera vaccine.
Assuntos
Vacinas contra Cólera/farmacologia , Vibrio cholerae/imunologia , Administração Oral , Análise de Variância , Animais , Anticorpos Antibacterianos/sangue , Carga Bacteriana , Western Blotting , Cólera/prevenção & controle , Vacinas contra Cólera/química , Vacinas contra Cólera/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/sangue , Lipopolissacarídeos/imunologia , Coelhos , Estatísticas não Paramétricas , Comprimidos com Revestimento Entérico/química , Comprimidos com Revestimento Entérico/farmacologia , Vacinas de Produtos Inativados/química , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/farmacologiaRESUMO
BACKGROUND: The World Health Organization considers leptospirosis the most neglected zoonotic disease in the last decades. One of the major obstacles in the developing of vaccines for the prevention of leptospirosis is the absence of cross-protection among unrelated serovars. It is accepted that cross-protection among related serovars is due to antibodies generated against lipopolysaccharides (LPs), whereas a cross-protection among unrelated serovars is rarely observed. OBJECTIVES: The objective of the study was to ascertain the existence of cross-protection among vaccine strains of different serovars. RESULTS: The results of this research demonstrated that a cross-protection among unrelated Leptospira serovars strain is possible. The Canicola strain is able to induce protection against homologous, Ballum and Copenhageni strains. The Mozdok strain induced protection only against a homologous challenge. Other strains showed a moderate cross-protection against a heterologous challenge. CONCLUSIONS: These findings suggest that the Canicola and Mozdok strains are ideal candidates for developing a new vaccine formulation for use in Cuba.
Assuntos
Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/imunologia , Reações Cruzadas , Leptospira/imunologia , Leptospirose/prevenção & controle , Animais , Vacinas Bacterianas/genética , Cricetinae , Modelos Animais de Doenças , Leptospira/classificação , Leptospira/genética , Leptospira/patogenicidade , Leptospirose/sangue , Leptospirose/imunologia , Mesocricetus , Reação em Cadeia da Polimerase , Fatores de Tempo , VirulênciaRESUMO
Research, development, and production of vaccines are still highly dependent on the use of animal models in the various evaluation steps. Despite this fact, there are strong interests and ongoing efforts to reduce the use of animals in vaccine development. Tuberculosis vaccine development is one important example of the complexities involved in the use of animal models for the production of new vaccines. This review summarises some of the general aspects related with the use of animals in vaccine research and production, as well as achievements and challenges towards the rational use of animals, particularly in the case of tuberculosis vaccine development.
RESUMO
Honduras was one of the Central American countries most severely hit by Hurricane Mitch. Torrential rains and heavy flooding created conditions conducive to a leptospirosis outbreak in the country. A group of Cuban scientists studied 68 patients from the Department of Cort�s - one of the country's hardest hit areas - presenting clinical and epidemiological profiles indicative of leptospirosis. Blood and serum samples were taken from all subjects. A microscopic agglutination test (MAT) was used to identify Leptospira strains and to assess protection conferred by vax-SPIRAL® (Cuban leptospirosis vaccine) against the isolated strain. Prevalence of leptospires in the kidneys and liver was also verified. A male predominance was found in the group aged 15-49 years. Municipalities in this Department with the largest number of cases were San Pedro Sula, La Lima, and Chamelec�n. The most frequent symptoms included fever, headache, myalgia, and generalized discomfort. Over 80% of subjects reported presence of rodents in their homes, as well as contact with stagnant water and domestic animals. The strain isolated from positive blood cultures was from the Icterohaemorrhagiae serogroup, which was highly virulent in the animal model used. Protection was 100% in hamsters inoculated with vax-SPIRAL® and subsequently challenged with the Honduran strain. Additionally, macroscopic analysis of organs from immunized animals that survived the challenge showed no signs of leptospirosis infection.
RESUMO
We describe a new method to obtain conjugates against Neisseria meningitidis serogroups A, B, C, Vibrio cholera, and Salmonella typhi and their immunogenicity in Balb/c mice. The saccharides were activated by basic hydrolysis with the generation of amine groups in the saccharidic chain, and these groups were linked to carboxyl groups of tetanus toxoid by via carbodiimida-mediated reaction. The resultant conjugates were administered to mice for the immunogenicity studies. The pirogenicity of LPS was measured by LAL assay. The anti-saccharide IgG, IgG1, and IgG2a antibodies were evaluated. A significant decrease in the pirogenicity of LPS after basic hydrolysis treatment was observed. The conjugates elicited higher titers of anti-polysaccharides or anti-LPS IgG, IgG1, and IgG2a in conjugates than in unconjugated saccharides. The results indicate that we have a new method for obtaining conjugated vaccines and we have demonstrated that after conjugation there was a change in the responses for all saccharides, from thymus-independent to thymus-dependent responses.
Assuntos
Lipopolissacarídeos/química , Toxoide Tetânico/química , Vacinas Conjugadas/química , Animais , Anticorpos Antibacterianos/sangue , Imunoglobulina G/sangue , Lipopolissacarídeos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Neisseria meningitidis/química , Neisseria meningitidis/imunologia , Salmonella typhi/química , Salmonella typhi/imunologia , Toxoide Tetânico/imunologia , Vacinas Conjugadas/isolamento & purificação , Vibrio cholerae/química , Vibrio cholerae/imunologiaRESUMO
The effect of the administration of a commercial preparation of human gamma globulins has been evaluated in a mouse model of intranasal infection with BCG. First, we demonstrated the passage of specific antibodies to saliva and lung lavage following the intranasal or intraperitoneal administration to mice of human gamma globulins. This treatment of mice inhibited BCG colonization of the lungs (p < 0.01). A similar inhibitory effect was observed after infection of mice with gamma globulin opsonized BCG organisms (p < 0.01). These results are relevant for the development of new strategies for the control and treatment of tuberculosis.
Assuntos
Mycobacterium bovis , Tuberculose/prevenção & controle , gama-Globulinas/uso terapêutico , Administração Intranasal , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Infusões Parenterais , Pulmão/imunologia , Pulmão/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium bovis/isolamento & purificação , Fagocitose , Saliva/imunologia , Tuberculose/imunologia , gama-Globulinas/administração & dosagem , gama-Globulinas/farmacocinéticaRESUMO
Immunization of BALB/c mice with an expression genomic library of Toxoplasma gondii induces a Th1-type immune response, with recognition of several T. gondii proteins (21 to 117 kDa) and long-term protective immunity against a lethal challenge. These results support further investigations to achieve a multicomponent anti-T. gondii DNA vaccine.