Accessing Complexity: The Dynamics of Virus-Specific T Cell Responses

• Published in: Annual review of immunology Vol. 18; no. 1; pp. 561 - 592
• Main Authors: Doherty, Peter C, Christensen, Jan P
• Format: Journal Article
• Language: English
• Published: Palo Alto, CA 94303-0139 Annual Reviews 01-01-2000; 4139 El Camino Way, P.O. Box 10139 Annual Reviews, Inc; USA
• Subjects: AIDS/HIV; Animals; CD4 antigen; CD8 antigen; CD8-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - virology; cell-mediated immunity; Humans; Immunologic Memory - immunology; inflammation; memory; pneumonia; recall response; T-Lymphocytes - immunology; T-Lymphocytes - virology; tetramers; Viruses - immunology
• ISSN: 0732-0582; 1545-3278
• DOI: 10.1146/annurev.immunol.18.1.561

The cellular dynamics of the immune system are complex and difficult to
measure. Access to this problematic area has been greatly enhanced by the
recent development of tetrameric complexes of MHC class I glycoprotein +
peptide (tetramers) for the direct staining of freshly isolated,
antigen-specific CD8
+
T cells. Analysis to date with both
naturally acquired and experimentally induced infections has established that
the numbers of virus-specific CD8
+
T cells present during both
the acute and memory phases of the host response are more than tenfold in
excess of previously suspected values. The levels are such that the
virus-specific CD8
+
set is readily detected in the human
peripheral blood lymphocyte compartment, particularly during persistent
infections. Experimentally, it is now possible to measure the extent of cycling
for tetramer
+
CD8
+
T cells during the acute and
memory phases of the host response to viruses. Dissection of the phenotypic,
functional, and molecular diversity of CD8
+
T cell populations
has been greatly facilitated. It is hoped it will also soon be possible to
analyze CD4
+
T cell populations in this way. Though these are
early days and there is an enormous amount to be done, our perceptions of the
shape of virus-specific cell-mediated immunity are changing rapidly.