RESUMEN
Immunogenicity and protective efficacy of three Campylobacter jejuni flagellum-secreted proteins, FlaC, FspA1, and FspA2, were compared by use of a mouse model. Mice were immunized intranasally with each protein with or without LTR192G as the adjuvant and challenged intranasally with C. jejuni 81-176 or CG8486. All three proteins were immunogenic, although FspA1 induced the highest levels of serum immunoglobulin G (IgG) and fecal IgA. Although immunogenic, FlaC provided only 18% protection against disease from C. jejuni 81-176. Immunization with FspA1 resulted in 57.8% protection without adjuvant or 63.8% protection with adjuvant against homologous challenge with 81-176. Alternatively, immunization with FspA2 provided 38.4% (without adjuvant) or 47.2% (with adjuvant) protection against disease from homologous challenge with CG8486. In contrast to FspA2, FspA1 provided some heterologous protection against C. jejuni CG8486 when delivered with (31.2%) or without (44.8%) LTR192G. These results suggest that FspA1 may be a good subunit vaccine candidate against C. jejuni disease.
Asunto(s)
Proteínas Bacterianas/inmunología , Vacunas Bacterianas/inmunología , Infecciones por Campylobacter/prevención & control , Campylobacter jejuni/patogenicidad , Flagelos/metabolismo , Flagelina/inmunología , Proteínas Recombinantes/inmunología , Animales , Anticuerpos Antibacterianos/sangre , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/genética , Infecciones por Campylobacter/microbiología , Campylobacter jejuni/genética , Campylobacter jejuni/inmunología , Campylobacter jejuni/metabolismo , Femenino , Flagelina/genética , Flagelina/aislamiento & purificación , Flagelina/metabolismo , Ratones , Ratones Endogámicos BALB C , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , VacunaciónRESUMEN
Helicobacter pylori infection in humans is responsible for the onset of severe gastric disorders and a vaccine would be an improvement over current antibiotic-based treatments. Lipopolysaccharide (LPS; O-chain PSâcoreâlipid A) is a main H. pylori cell wall component, whose O-chain PS exhibits molecular mimicry and therefore any LPS-based vaccine cannot contain O-chain epitopes. Here, the conjugation of de-lipidated H. pylori O:2 LPS to BSA and its immunogenicity in mice is described. IgG antibodies were observed to recognize the LPSs of representative H. pylori serotypes O:1, O:2 and O:5, and more significantly, the core region of H. pylori. This study showed that a monovalent H. pylori LPS conjugate can elicit antibodies that recognize other serotype-specific H. pylori LPSs and specifically the structurally conserved LPS inner-regions.