Abstract
Mononuclear phagocytes which express the HIV entry receptor CD4 have been implicated as possible sites of virus replication in brain, but there is still considerable uncertainty as to which cells in the CNS express CD4 Ag. Although it is not susceptible to HIV infection the rat provides a model to define expression of the CD4 Ag on MO in brain. We report that the CD4 epitopes W3/25 and OX35 are found only on monocytes, MO, microglia, and occasional lymphocytes and not on neurons, other glia, or endothelium. CD4 Ag levels are modulated during microglial differentiation, after reactivation after local inflammation, and within the intact blood brain barrier. MO and microglia also express other potential plasma membrane binding and entry sites for HIV viz Fc and complement receptors that are regulated independently of CD4.
Full Text
The Full Text of this article is available as a PDF (486.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Crocker P. R., Jefferies W. A., Clark S. J., Chung L. P., Gordon S. Species heterogeneity in macrophage expression of the CD4 antigen. J Exp Med. 1987 Aug 1;166(2):613–618. doi: 10.1084/jem.166.2.613. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Funke I., Hahn A., Rieber E. P., Weiss E., Riethmüller G. The cellular receptor (CD4) of the human immunodeficiency virus is expressed on neurons and glial cells in human brain. J Exp Med. 1987 Apr 1;165(4):1230–1235. doi: 10.1084/jem.165.4.1230. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jefferies W. A., Brandon M. R., Hunt S. V., Williams A. F., Gatter K. C., Mason D. Y. Transferrin receptor on endothelium of brain capillaries. Nature. 1984 Nov 8;312(5990):162–163. doi: 10.1038/312162a0. [DOI] [PubMed] [Google Scholar]
- Jefferies W. A., Green J. R., Williams A. F. Authentic T helper CD4 (W3/25) antigen on rat peritoneal macrophages. J Exp Med. 1985 Jul 1;162(1):117–127. doi: 10.1084/jem.162.1.117. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maddon P. J., Dalgleish A. G., McDougal J. S., Clapham P. R., Weiss R. A., Axel R. The T4 gene encodes the AIDS virus receptor and is expressed in the immune system and the brain. Cell. 1986 Nov 7;47(3):333–348. doi: 10.1016/0092-8674(86)90590-8. [DOI] [PubMed] [Google Scholar]
- Perry V. H., Brown M. C., Gordon S. The macrophage response to central and peripheral nerve injury. A possible role for macrophages in regeneration. J Exp Med. 1987 Apr 1;165(4):1218–1223. doi: 10.1084/jem.165.4.1218. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perry V. H., Hume D. A., Gordon S. Immunohistochemical localization of macrophages and microglia in the adult and developing mouse brain. Neuroscience. 1985 Jun;15(2):313–326. doi: 10.1016/0306-4522(85)90215-5. [DOI] [PubMed] [Google Scholar]
- Porterfield J. S. Antibody-dependent enhancement of viral infectivity. Adv Virus Res. 1986;31:335–355. doi: 10.1016/s0065-3527(08)60268-7. [DOI] [PubMed] [Google Scholar]
- Robinson A. P., White T. M., Mason D. W. Macrophage heterogeneity in the rat as delineated by two monoclonal antibodies MRC OX-41 and MRC OX-42, the latter recognizing complement receptor type 3. Immunology. 1986 Feb;57(2):239–247. [PMC free article] [PubMed] [Google Scholar]
- Stewart S. J., Fujimoto J., Levy R. Human T lymphocytes and monocytes bear the same Leu-3(T4) antigen. J Immunol. 1986 May 15;136(10):3773–3778. [PubMed] [Google Scholar]