Send to:

Choose Destination
See comment in PubMed Commons below
Genes Immun. 2005 Dec;6(8):663-71.

Characterization of the human CD5 endogenous retrovirus-E in B lymphocytes.

Author information

  • 1Laboratory of Immunology, Brest University Medical School, 2 avenue Foch, BP824, F-29609 Brest, France.


All T lymphocytes and some B lymphocytes express CD5. This coreceptor is encoded by one gene that consists of 11 exons. We have previously described a B cell-specific alternative exon 1, leading to the synthesis of a protein, devoid of leader peptide, and, therefore, retained in the cytoplasm. The novel exon 1 originates from a human endogenous retrovirus (HERV) at a time interval between the divergence of New World monkeys from Old World monkeys, and prior to the divergence of humans from Old World monkeys. Based on sequence similarity to gamma-retroviruses, it was categorized as class I: based on the specificity of its primer binding site, it was allotted to the subclass E, and based on its location within the cd5 gene, named HERV-E.CD5. Alternative transcripts were detected in lymphoid organs including fetal liver (not adult liver), more particularly in CD5-negative cell surface B-1b than in CD5-positive cell surface B-1a, and not at all in B-2 cells. By alignment of 5' long terminal repeats, HERV-E.CD5 was distinguished from similar proviruses. This could be central to the regulation of membrane expression of CD5 in human B lymphocytes, and, thereby, to the strength of the B-cell antigen receptor signaling.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Nature Publishing Group
    Loading ...
    Write to the Help Desk