Previous Article | Next Article ![]()
Journal of Virology, July 1999, p. 5373-5380, Vol. 73, No. 7
Institute of Microbiology, University of
Padua Medical School, Padua, Italy 351212;
Oregon Regional Primate Research Center,
Received 22 December 1998/Accepted 25 March 1999
A soluble form of the CD4 receptor (sCD4) can either enhance or
inhibit the infection of cells by simian immunodeficiency virus (SIV)
and human immunodeficiency virus. We investigated the basis for these
varying effects by studying the entry of three SIV isolates
into CD4-positive and CD4-negative cells expressing different chemokine
receptors. Infection of CD4-negative cells depended upon the viral
envelope glycoproteins and upon the chemokine receptor,
with CCR5 and gpr15 being more efficient than STRL33. Likewise,
enhancement of infection by sCD4 was observed when CCR5- and
gpr15-expressing target cells were used but not when those expressing
STRL33 were used. The sCD4-mediated enhancement of virus infection of
CD4-negative, CCR5-positive cells was related to the sCD4-induced
increase in binding of the viral gp120 envelope glycoprotein to CCR5. Inhibitory effects of sCD4 could
largely be explained by competition for virus attachment to cellular
CD4 rather than other detrimental effects on virus infectivity (e.g., disruption of the envelope glycoprotein spike). Consistent
with this, the sCD4-activated SIV envelope
glycoprotein intermediate on the virus was long-lived.
Thus, the net effect of sCD4 on SIV infectivity appears to
depend upon the degree of enhancement of chemokine receptor binding and
upon the efficiency of competition for cellular CD4.
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Effects of Soluble CD4 on Simian Immunodeficiency
Virus Infection of CD4-Positive and CD4-Negative Cells
*
Corresponding author. Mailing address: Department of
Cancer Immunology and AIDS, Dana-Farber Cancer Institute, 44 Binney
St., JFB 824, Boston, MA 02115. Phone: (617) 632-3371. Fax: (617)
632-4338. E-mail: joseph_sodroski{at}dfci.harvard.edu.
Journal of Virology, July 1999, p. 5373-5380, Vol. 73, No. 7
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|