Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-12-21
pubmed:abstractText
Antimicrobial memory CD8+ T cell responses are not readily expanded by either repeated infections or immunizations. This is a major obstacle to the development of T cell vaccines. Prime-boost immunization with heterologous microbes sharing the same CD8+ epitope can induce a large expansion of the CD8+ response; however, different vectors vary greatly in their ability to boost for reasons that are poorly understood. To investigate how efficient memory T cell expansion can occur, we evaluated immune regulatory events and Ag presentation after secondary immunization with strong and weak boosting vectors. We found that dendritic cells were essential for T cell boosting and that Ag presentation by these cells was regulated by cognate memory CD8+ T cells. When weak boosting vectors were used for secondary immunization, pre-established CD8+ T cells were able to effectively curtail Ag presentation, resulting in limited CD8+ T cell expansion. In contrast, a strong boosting vector, vaccinia virus, induced highly efficient Ag presentation that overcame regulation by cognate T cells and induced large numbers of memory CD8+ T cells to expand. Thus, efficient targeting of Ag to dendritic cells in the face of cognate immunity is an important requirement for T cell expansion.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
180
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
64-71
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Memory CD8+ T cell responses expand when antigen presentation overcomes T cell self-regulation.
pubmed:affiliation
Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural