Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2009-10-5
pubmed:abstractText
The T cell branch of the immune system has been extensively studied in the elderly and it is known that the elderly have impaired immune function, mainly due to the chronic antigenic load that ultimately causes shrinkage of the T cell repertoire and filling of the immunologic space with memory T cells. In the present paper, we describe the IgD(-)CD27(-) double-negative B cell population which (as we have recently described) is higher in the elderly. Most of these cells were IgG(+). Evaluation of the telomere length and expression of the ABCB1 transporter and anti-apoptotic molecule, Bcl2, shows that they have the markers of memory B cells. We also show that these cells do not act as antigen presenting cells, as indicated by the low levels of CD80 and DR, nor do they express significant levels of the CD40 molecule necessary to interact with T lymphocytes through the ligand, CD154. Hence, we hypothesize that these expanded cells are late memory or exhausted cells that have down-modulated the expression of CD27 and filled the immunologic space in the elderly. These cells might be the age-related manifestation of time-enduring stimulation or dysregulation of the immune system.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1872-6216
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
681-90
pubmed:meshHeading
pubmed-meshheading:19698733-Adult, pubmed-meshheading:19698733-Age Factors, pubmed-meshheading:19698733-Aged, pubmed-meshheading:19698733-Aged, 80 and over, pubmed-meshheading:19698733-Aging, pubmed-meshheading:19698733-Antigens, CD19, pubmed-meshheading:19698733-Antigens, CD27, pubmed-meshheading:19698733-Antigens, CD40, pubmed-meshheading:19698733-Antigens, CD80, pubmed-meshheading:19698733-B-Lymphocyte Subsets, pubmed-meshheading:19698733-Cells, Cultured, pubmed-meshheading:19698733-Flow Cytometry, pubmed-meshheading:19698733-HLA-DR Antigens, pubmed-meshheading:19698733-Humans, pubmed-meshheading:19698733-Immunoglobulin D, pubmed-meshheading:19698733-Immunologic Memory, pubmed-meshheading:19698733-Ki-67 Antigen, pubmed-meshheading:19698733-Middle Aged, pubmed-meshheading:19698733-P-Glycoprotein, pubmed-meshheading:19698733-Proto-Oncogene Proteins c-bcl-2, pubmed-meshheading:19698733-Telomere, pubmed-meshheading:19698733-Young Adult
pubmed:year
2009
pubmed:articleTitle
A double-negative (IgD-CD27-) B cell population is increased in the peripheral blood of elderly people.
pubmed:affiliation
Gruppo di Studio sull'Immunosenescenza, Dipartimento di Biopatologia e Metodologie Biomediche, Università di Palermo, 90134 Palermo, Italy. gcolonna@unipa.it
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't