Linked Life Data

17982068

Source:http://linkedlifedata.com/resource/pubmed/id/17982068

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2007-11-5
pubmed:abstractText
As in mammals, B cell maturation in the amphibian Xenopus involves somatic hypermutation (SHM) and class switch recombination to diversify the B cell receptor repertoire in response to Ag stimulation. Unlike mammals, however, the resulting increase in Ab affinity is poor in Xenopus, which is possibly related to the absence of germinal centers and a suboptimal selection mechanism of SHM. In mammals, both SHM and class switch recombination are mediated by the activation-induced cytidine deaminase enzyme and under Ag-dependent regulation. Given its evolutionary conservation in jawed vertebrates, we used activation-induced cytidine deaminase as a marker to monitor and localize B cell maturation in Xenopus upon immune responses and during early development. In adult, Xenopus laevis AID (XlAID) was detected mainly in the spleen, where cells expressing XlAID were preferentially distributed in follicular B cell zones, although some XlAID(+) cells were also found in the red pulp. XlAID was markedly up-regulated in the spleen with different kinetics upon bacterial stimulation and viral infection. However, during secondary anti-viral response XlAID was also noticeably expressed by PBLs, suggesting that XlAID remains active in a subset of circulating B cells. During ontogeny, XlAID expression was detected as early as 5 days postfertilization in liver before the first fully differentiated B cells appear. Concomitant with appearance of mature B cells XlAID was up-regulated upon bacterial stimulation or viral infection at later larval stages. This study highlights the conserved involvement of XlAID during Ag-dependent B cell responses in Xenopus but also suggests another role in B cell differentiation earlier in ontogeny.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
179
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6783-9
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:17982068-Animals, pubmed-meshheading:17982068-Antigens, Bacterial, pubmed-meshheading:17982068-Antigens, Viral, pubmed-meshheading:17982068-B-Lymphocytes, pubmed-meshheading:17982068-Bacterial Infections, pubmed-meshheading:17982068-Biological Evolution, pubmed-meshheading:17982068-Cell Differentiation, pubmed-meshheading:17982068-Cytidine Deaminase, pubmed-meshheading:17982068-Enzyme Activation, pubmed-meshheading:17982068-Gene Expression Regulation, Developmental, pubmed-meshheading:17982068-Gene Expression Regulation, Enzymologic, pubmed-meshheading:17982068-Germinal Center, pubmed-meshheading:17982068-Immunoglobulin Class Switching, pubmed-meshheading:17982068-Larva, pubmed-meshheading:17982068-Liver, pubmed-meshheading:17982068-Mammals, pubmed-meshheading:17982068-Receptors, Antigen, B-Cell, pubmed-meshheading:17982068-Recombination, Genetic, pubmed-meshheading:17982068-Somatic Hypermutation, Immunoglobulin, pubmed-meshheading:17982068-Spleen, pubmed-meshheading:17982068-Up-Regulation, pubmed-meshheading:17982068-Virus Diseases, pubmed-meshheading:17982068-Xenopus Proteins, pubmed-meshheading:17982068-Xenopus laevis
pubmed:year
2007
pubmed:articleTitle
Localization and differential expression of activation-induced cytidine deaminase in the amphibian Xenopus upon antigen stimulation and during early development.
pubmed:affiliation
Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural