An early expansion of CD8alphabeta T cells, but depletion of resident CD8alphaalpha T cells, occurs in the intestinal epithelium during primary simian immunodeficiency virus infection.

Abstract

OBJECTIVES:

To evaluate changes in the phenotypic heterogeneity and function of CD8 T cells in the intestinal epithelium during primary SIV infection.

DESIGN:

Previous studies have shown an increased prevalence of CD8 T cells in the intestinal epithelium in HIV and SIV infections. As intestinal CD8 T cells are a heterogeneous population we evaluated their phenotypic distribution (CD8alphabeta, CD8alphaalpha) and function [interferon (IFN)-gamma production] during primary SIV infection.

METHODS:

The phenotype and functional potential of CD8 intestinal intraepithelial lymphocytes (IEL) prior to and following SIV infection were determined using flow cytometry.

RESULTS:

IEL were found to harbor CD8alphabetaCD3, CD8alphaalphaCD3 and CD8alphaalpha+CD3- T-cell subsets. Most of the CD8CD4 double positive IEL expressed CD8alphaalpha homodimers. In primary SIV infection the frequency of CD8alphabetaCD3 T cells increased dramatically whereas the frequency of CD8alphaalpha T cells declined. A higher frequency of CD8alphabetaKi-67 IEL was observed following SIV infection suggesting that local cell proliferation might have contributed to an increased prevalence of CD8alphabeta IEL. In contrast, a severe depletion of CD8alphaalphaCD4 IEL occurred which contributed to the depletion of CD8alphaalpha IEL. The CD8alphabeta IEL were the major producers of IFN-gamma in the intestinal epithelium and the frequency of IFN-gamma-producing CD8alphabeta IEL was enhanced considerably in primary infection.

CONCLUSIONS:

CD8alphabeta IEL may be important in generating early antiviral responses at the intestinal epithelium. However, alterations in CD8 T-cell subsets and their function may reflect early immunopathogenic events in the intestinal mucosa.

• Authors: J J Mattapallil, E Reay, S Dandekar
• Journal: AIDS (London, England) (AIDS) Vol. 14 Issue 6 Pg. 637-46 (Apr 14 2000) ISSN: 0269-9370 [Print] England
• PMID: 10807186 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Receptors, Antigen, T-Cell, alpha-beta
• Interferon-gamma

Topics

• Animals
• CD4-Positive T-Lymphocytes (immunology)
• CD8-Positive T-Lymphocytes (immunology)
• Interferon-gamma (metabolism)
• Intestinal Mucosa (immunology, virology)
• Jejunum (immunology, virology)
• Lymphocyte Activation
• Macaca mulatta
• Phenotype
• Receptors, Antigen, T-Cell, alpha-beta (metabolism)
• Simian Acquired Immunodeficiency Syndrome (immunology, virology)
• Simian Immunodeficiency Virus (immunology, isolation & purification)
• T-Lymphocyte Subsets (immunology)