scholarly journals Shedding of Escherichia coli O157:H7 in Calves Is Reduced by Prior Colonization with the Homologous Strain

2007 ◽  
Vol 73 (11) ◽  
pp. 3765-3767 ◽  
Author(s):  
Stuart W. Naylor ◽  
Allen Flockhart ◽  
Pablo Nart ◽  
David G. E. Smith ◽  
John Huntley ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Protective Immunity ◽  
Escherichia Coli O157 ◽  
Natural Reservoir ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Bacterial Antigens ◽  
Homologous Strain ◽  
Experimental Challenge

ABSTRACT Enterohemorrhagic Escherichia coli O157:H7 has a natural reservoir in the intestinal tracts of cattle. Colonization is asymptomatic and transient, but it is not clear if protective immunity is induced. This study demonstrates that prior colonization induces humoral immune responses to bacterial antigens and reduces bacterial shedding after experimental challenge with the homologous strain.

scholarly journals Correlates of Immune Protection following Cutaneous Immunization with an Attenuated Burkholderia pseudomallei Vaccine

2013 ◽  
Vol 81 (12) ◽  
pp. 4626-4634 ◽  
Author(s):  
Ediane B. Silva ◽  
Andrew Goodyear ◽  
Marjorie D. Sutherland ◽  
Nicole L. Podnecky ◽  
Mercedes Gonzalez-Juarrero ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Protective Immunity ◽  
Burkholderia Pseudomallei ◽  
Partial Protection ◽  
Content Type ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Immune Correlates ◽  
Draining Lymph Nodes

ABSTRACTInfections with the Gram-negative bacteriumBurkholderia pseudomallei(melioidosis) are associated with high mortality, and there is currently no approved vaccine to prevent the development of melioidosis in humans. Infected patients also do not develop protective immunity to reinfection, and some individuals will develop chronic, subclinical infections withB. pseudomallei. At present, our understanding of what constitutes effective protective immunity againstB. pseudomalleiinfection remains incomplete. Therefore, we conducted a study to elucidate immune correlates of vaccine-induced protective immunity against acuteB. pseudomalleiinfection. BALB/c and C57BL/6 mice were immunized subcutaneously with a highly attenuated, Select Agent-excludedpurMdeletion mutant ofB. pseudomallei(strain Bp82) and then subjected to intranasal challenge with virulentB. pseudomalleistrain 1026b. Immunization with Bp82 generated significant protection from challenge withB. pseudomallei, and protection was associated with a significant reduction in bacterial burden in lungs, liver, and spleen of immunized mice. Humoral immunity was critically important for vaccine-induced protection, as mice lacking B cells were not protected by immunization and serum from Bp82-vaccinated mice could transfer partial protection to nonvaccinated animals. In contrast, vaccine-induced protective immunity was found to be independent of both CD4 and CD8 T cells. Tracking studies demonstrated uptake of the Bp82 vaccine strain predominately by neutrophils in vaccine-draining lymph nodes and by smaller numbers of dendritic cells (DC) and monocytes. We concluded that protection following cutaneous immunization with a live attenuatedBurkholderiavaccine strain was dependent primarily on generation of effective humoral immune responses.

scholarly journals Yersinia pestis caf1 Variants and the Limits of Plague Vaccine Protection

2008 ◽  
Vol 76 (5) ◽  
pp. 2025-2036 ◽  
Author(s):  
Lauriane E. Quenee ◽  
Claire A. Cornelius ◽  
Nancy A. Ciletti ◽  
Derek Elli ◽  
Olaf Schneewind
Keyword(s):  
Immune Responses ◽  
Yersinia Pestis ◽  
Protective Immunity ◽  
Wild Type ◽  
Vaccine Protection ◽  
Subunit Vaccines ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Plague Vaccine ◽  
Highly Virulent

ABSTRACT Yersinia pestis, the highly virulent agent of plague, is a biological weapon. Strategies that prevent plague have been sought for centuries, and immunization with live, attenuated (nonpigmented) strains or subunit vaccines with F1 (Caf1) antigen is considered effective. We show here that immunization with live, attenuated strains generates plague-protective immunity and humoral immune responses against F1 pilus antigen and LcrV. Y. pestis variants lacking caf1 (F1 pili) are not only fully virulent in animal models of bubonic and pneumonic plague but also break through immune responses generated with live, attenuated strains or F1 subunit vaccines. In contrast, immunization with purified LcrV, a protein at the tip of type III needles, generates protective immunity against the wild-type and the fully virulent caf1 mutant strain, in agreement with the notion that LcrV can elicit vaccine protection against both types of virulent plague strains.

scholarly journals Yersinia pestis IS1541 Transposition Provides for Escape from Plague Immunity

2009 ◽  
Vol 77 (5) ◽  
pp. 1807-1816 ◽  
Author(s):  
Claire A. Cornelius ◽  
Lauriane E. Quenee ◽  
Derek Elli ◽  
Nancy A. Ciletti ◽  
Olaf Schneewind
Keyword(s):  
Immune Responses ◽  
Yersinia Pestis ◽  
Protective Immunity ◽  
Infectious Agent ◽  
Inhibitory Effect ◽  
Effector Proteins ◽  
Host Cells ◽  
Specific Antibodies ◽  
Humoral Immune ◽  
Humoral Immune Responses

ABSTRACTYersinia pestisis perhaps the most feared infectious agent due to its ability to cause epidemic outbreaks of plague disease in animals and humans with high mortality. Plague infections elicit strong humoral immune responses against the capsular antigen (fraction 1 [F1]) ofY. pestis, and F1-specific antibodies provide protective immunity. Here we asked whetherY. pestisgenerates mutations that enable bacterial escape from protective immunity and isolated a variant with an IS1541insertion incaf1Aencoding the F1 outer membrane usher. Thecaf1A::IS1541insertion prevented assembly of F1 pili and provided escape from plague immunity via F1-specific antibodies without a reduction in virulence in mouse models of bubonic or pneumonic plague. F1-specific antibodies interfere withY. pestistype III transport of effector proteins into host cells, an inhibitory effect that was overcome by thecaf1A::IS1541insertion. These findings suggest a model in which IS1541insertion intocaf1Aprovides for reversible changes in envelope structure, enablingY. pestisto escape from adaptive immune responses and plague immunity.

scholarly journals Novel protein targets of the humoral immune response to Listeria monocytogenes infection in rabbits

2007 ◽  
Vol 56 (7) ◽  
pp. 888-895 ◽  
Author(s):  
Wei Ling Yu ◽  
Hanhong Dan ◽  
Min Lin
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Immune Responses ◽  
Humoral Immune Response ◽  
Protective Immunity ◽  
Rabbit Model ◽  
Protein Targets ◽  
Humoral Immune ◽  
Humoral Immune Responses

The role of the humoral immune response in protective immunity against listerial infection has been overlooked and is essentially unknown. This study aimed to discover the protein targets of Listeria monocytogenes that elicit an antibody response following infection in a rabbit model. A genomic expression library for L. monocytogenes was constructed and differentially screened to identify genes encoding proteins that reacted with antiserum from rabbits infected with live L. monocytogenes serotype 4b (RαL), but not with that from animals immunized with heat-killed bacteria (RαK). Thirty-one clones expressing proteins that reacted exclusively with RαL were identified and sequenced. Sequence analysis, together with Western blot analysis of the proteins expressed from positive clones, led to the identification of eight L. monocytogenes proteins as targets of humoral immune responses during listerial infection: three internalin members (InlA, InlD and InlC2) and five novel proteins of unknown function (designated IspA, IspB, IspC, IspD and IspE, respectively). Exhibition of humoral immune responses to these proteins in actively infected rabbits but not in animals receiving heat-killed L. monocytogenes suggested that they were induced or significantly upregulated in vivo during infection and thus are important in Listeria pathogenesis. With the exception of antibodies to InlA, this is the first demonstration of antibodies to the other seven proteins in infected hosts. These immunogenic proteins may be useful candidates for elucidation of the role of antibodies in protective immunity in the context of listerial infection, as well as potential targets for serodiagnostic reagents and vaccine and drug development.

Sign in / Sign up

Export Citation Format

Share Document