Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2001-9-20
pubmed:abstractText
Ag-specific proliferation of CD4+ T cells is regulated, in part, by costimulatory signals through CD28. The proliferative response during primary activation is an important determinant of the ability of the T cell to respond to Ag re-encounter. Proliferation of mature CD4+ T cells during lymphopenia (homeostatic proliferation) requires interaction with endogenous peptide MHC. However, the role of costimulation during homeostatic proliferation is unclear, as is the ability of homeostatic proliferation to regulate secondary T cell responses. Using a TCR transgenic system and serial adoptive transfers we find that homeostatic proliferation of CD4+ T cells occurs for at least 5 wk after adoptive transfer into recombination-activating gene (RAG)-/- recipients. Two discrete populations of proliferating T cells can be resolved, one that is highly proliferative and dependent on CD28 signaling, and the other that contains cells undergoing low levels of CD28-independent proliferation. Importantly, naive CD4+ T cells that have undergone homeostatic proliferation acquire both phenotypic and functional characteristics of true memory cells. These studies indicate that functional memory T cells can be generated by encounters with endogenous Ags only. This mechanism of T cell regeneration is possibly active during lymphopenia due to viral infections, such as HIV, transplantation, or cancer therapy, and may explain selected autoimmune diseases.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
167
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3699-707
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11564785-Adoptive Transfer, pubmed-meshheading:11564785-Animals, pubmed-meshheading:11564785-Antigens, CD28, pubmed-meshheading:11564785-CD4-Positive T-Lymphocytes, pubmed-meshheading:11564785-Cells, Cultured, pubmed-meshheading:11564785-Cytokines, pubmed-meshheading:11564785-Fluoresceins, pubmed-meshheading:11564785-Fluorescent Dyes, pubmed-meshheading:11564785-Genes, RAG-1, pubmed-meshheading:11564785-Homeostasis, pubmed-meshheading:11564785-Immunologic Memory, pubmed-meshheading:11564785-Immunophenotyping, pubmed-meshheading:11564785-Kinetics, pubmed-meshheading:11564785-Lymphocyte Activation, pubmed-meshheading:11564785-Lymphopenia, pubmed-meshheading:11564785-Mice, pubmed-meshheading:11564785-Mice, Knockout, pubmed-meshheading:11564785-Ovalbumin, pubmed-meshheading:11564785-Succinimides, pubmed-meshheading:11564785-T-Lymphocyte Subsets
pubmed:year
2001
pubmed:articleTitle
A closer look at homeostatic proliferation of CD4+ T cells: costimulatory requirements and role in memory formation.
pubmed:affiliation
Department of Medicine, University of Pennsylvania, 415 Curie Blvd., Philadelphia, PA 19104, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't