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Reduced CD21 (CR2) and CD54 (ICAM-1) expression in MT2 cells with HIV-1 or HIV-2 strains
C Larcher1, N Julen, W M Prodinger
1Institut für Hygiene, Universität Innsbruck, Austria.
Abstract:
Alterations in the expression of cell-surface receptors have been reported in HIV-infected cells for CD4, CD25 (IL-2 receptor), CD2, CD3 and CD8 and CD26. In the present study we provide evidence that CD21 is down-regulated in the human T-lymphoblastoid cell line MT2 after infection with HIV-1 and -2 isolates. The same effect was observed with ICAM-1 (CD54). CD21 expression was monitored by means of fluorescence intensity, its functional ability to bind to C3d and by quantitative measurement of CD21-antigen in supernatants and cell lysates using an immunoassay. In addition, the decrease of CD21 and ICAM-1-specific mRNA suggests a mechanism at a transcriptional level. Our data suggest that HIV might have a direct influence on the receptor expression.
Insights
Human immunodeficiency virus (HIV) infection down-regulates CD21 and ICAM-1 cell-surface receptors in T-lymphoblastoid cells. This suggests HIV directly impacts receptor expression at a transcriptional level.
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- Cell-surface receptor expression is altered in HIV-infected cells.
- Previous studies reported changes in CD4, CD25, CD2, CD3, CD8, and CD26 expression.
Purpose of the Study:
- To investigate the effect of HIV infection on CD21 and ICAM-1 (CD54) expression in human T-lymphoblastoid MT2 cells.
- To elucidate the mechanism underlying observed changes in receptor expression.
Main Methods:
- Monitoring CD21 expression via fluorescence intensity and C3d binding assays.
- Quantitative immunoassay for CD21-antigen in cell supernatants and lysates.
- Measurement of CD21 and ICAM-1 specific mRNA levels.
Main Results:
- HIV-1 and HIV-2 infection led to down-regulation of CD21 expression in MT2 cells.
- A similar decrease in ICAM-1 expression was observed.
- Reduced CD21 and ICAM-1 mRNA levels indicate a transcriptional regulation mechanism.
Conclusions:
- HIV infection directly influences the expression of CD21 and ICAM-1 on T-lymphoblastoid cells.
- The observed down-regulation occurs at the transcriptional level.