In vivo expansion coincident with excessive in vitro cell death within the memory subset of CD8+ T cells in HIV type 1 infection
| Autor: | Emiliano N. Mugnaini, Jan E. Brinchmann, Mette Sannes, Lise L. Haaheim |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Receptors
Antigen T-Cell alpha-beta Immunology chemical and pharmacologic phenomena Apoptosis HIV Infections CD8-Positive T-Lymphocytes Interleukin 21 CD28 Antigens Antigens CD T-Lymphocyte Subsets Virology Cytotoxic T cell Humans CD40 biology Cell growth T-cell receptor CD28 hemic and immune systems T lymphocyte Molecular biology Infectious Diseases biology.protein HIV-1 Immunologic Memory CD8 |
| Zdroj: | AIDS research and human retroviruses. 15(3) |
| ISSN: | 0889-2229 |
| Popis: | In HIV-1-infected individuals the CD8+ T cell subset is considerably expanded. This has been shown to be caused predominantly by an increase in the number of CD8+CD28- T cells. To characterize further the subsets of CD8+ T cells, we have performed analyses of cell surface phenotype, T cell receptor Vbeta usage, and ability to survive in unstimulated cultures. CD8+CD28- T cells frequently expressed CD45RA. Nonetheless, coincident expression of CD95 (Fas) and high levels of integrins suggested that these cells were immunologically experienced. Contrary to what has been observed in CD8+CD28- T cells from uninfected individuals, a common hierarchy of Vbeta usage was found in CD8+CD28- T cells from HIV-1-infected individuals, which was adhered to by all the study participants, and which was shown to be similar to that observed within CD8+CD28+ T cells. Cells from the memory subsets of CD8+ T cells showed a high incidence of spontaneous death in unstimulated cultures, indicating that these cells have received signals for death by apoptosis in vivo. In contrast, most naive CD8+CD28+CD45RA+ cells survived. The CD8+CD28- memory subset is expanded in vivo despite evidence for coincident excessive cell death in vitro. Our results are consistent with the notion that frequent transitions occur from the memory CD8+CD28+CD45RA- T cell subset to the end-stage CD8+CD28- subset during HIV-1 infection. |
| Databáze: | OpenAIRE |
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