Journal
JOURNAL OF EXPERIMENTAL MEDICINE
Volume 192, Issue 1, Pages 63-75Publisher
ROCKEFELLER UNIV PRESS
DOI: 10.1084/jem.192.1.63
Keywords
cytotoxic T lymphocytes; HIV; cytokines; tetramers; perforin
Categories
Funding
- NIAID NIH HHS [R01 AI44595] Funding Source: Medline
Ask authors/readers for more resources
Thc use of peptide-human histocompatibility leukocyte antigen (HLA) class I tetrameric complexes to identify antigen-specific CD8(+) T cells has provided a major development in our understanding of their role in controlling viral infections. However, questions remain about the exact function of these cells, particularly in HIV infection. Virus-specific cytotoxic T lymphocytes exert much of their activity by secreting soluble factors such as cytokines and chemokines. We describe here a method that combines the use of tetramers and intracellular staining to examine the functional heterogeneity of antigen-specific CD8(+) T cells es vivo. After stimulation by specific peptide antigen, secretion of interferon (IFN)-gamma, tunlor necrosis factor (TNF)-alpha, macrophage inflammatory protein (MIP)-1 beta, and perforin is analyzed by FACS(R) within the tetramer-positive population in peripheral blood. Using this method, we have assessed the functional phenotype of HIV-specific CD8(+) T cells compared with cytomegalovirus (CMV)-specific CD8(+) T cells: in HIV chronic infection. We show that the majority of circulating CD8(+) T cells specific for CMV and HIV antigens are functionally active with regards to the secretion of antiviral cytokines ill response to antigen, although a subset of tetramer-staining cells was identified that secretes IFN-gamma and MIP-1 beta but not TNF-alpha. However, a striking filming is that HIV-specific CD8(+) T cells express significantly lower levels of perforin than CMV-specific CD8(+) T cells. This lack of perforin is linked with persistent CD27 expression on HIV-specific cells, suggesting impaired maturation, and specific lysis ex vivo is lower for HIV-specific compared with CMV-specific cells from the same donor. Thus, HIV-specific CD8(+) T cells are impaired in cytolytic activity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available