AIDS Weekly Plus

31

Journal News April 28, 1997
Reviews and Information From Peer-Reviewed Journals Worldwide... Compiled by Alan D. Henderson
Chemokines
Bleul, C.C.; Wu, L.J.; Hoxie, J.A.; Springer, T.A.; Mackay, C.R. "The HIV Coreceptors CXCR4 and CCR5 Are Differentially
Expressed and Regulated on Human T Lymphocytes." Proceedings of the National Academy of Sciences of the United States
of America, March 4, 1997;94(5):1925-1930.
According to the authors' abstract of an article published in Proceedings of the National Academy of
Sciences of the United States of America, "The chemokine receptors CXCR4 and CCR5 function as
coreceptors for HIV-1 entry into CD4' cells. During the early stages of HIV infection, viral isolates tend to
use CCR5 for viral entry, while later isolates tend to use CXCR4. The pattern of expression of these
chemokine receptors on T-cell subsets and their regulation has important implications for AIDS
pathogenesis and lymphocyte recirculation. A mAb to CXCR4, 12G5, showed partial inhibition of
chemotaxis and calcium influx induced by SDF-1, the natural ligand of CXCR4. 12G5 stained
predominantly the naive, unactivated CD26(low) CD45RA CD45RO T lymphocyte subset of peripheral
blood lymphocytes. In contrast, a mAb specific for CCR5, 5C7, stained CD26(high) CD45RA(low)
CD45RO' T lymphocytes, a subset thought to represent previously activated/memory cells. CXCR4
expression was rapidly up-regulated on peripheral blood mononuclear cells during phytohemagglutinin
stimulation and interleukin 2 priming, and responsiveness to SDF-1 increased simultaneously. CCR5
expression, however, showed only a gradual increase over 12 days of culture with interleukin 2, while Tcell activation with phytohemagglutinin was ineffective. Taken together, the data suggest distinct
functions for the two receptors and their ligands in the migration of lymphocyte subsets through lymphoid
and nonlymphoid tissues. Furthermore, the largely reciprocal expression of CXCR4 and CCR5 among
peripheral blood T cells implies distinct susceptibility of T-cell subsets to viral entry by T-cell line-tropic
versus macrophage-tropic strains during the course of HIV infection." The corresponding author for this
study is: CR Mackay, Leukosite Inc, 215 1ST St, Cambridge, MA 02142 USA. For subscription
information for this journal contact the publisher: Natl Acad Press, 2101 Constitution Ave NW,
Washington, DC 20418.
Cytomegaloiru4s Retinitis
Irvine, A.R.; Lonn, L.; Schwartz, 0.; Zarbin, M.; Ballesteros, F; Kroll, S. "Retinal Detachment in AIDS: Long Term Results after
Repair with Silicone Oil." British Journal of Ophthalmology, March 1997;81(3):180-183.
According to the authors' abstract of an article published in British Journal of Ophthalmology, "Aims:
To study the long term results of vitrectomy and silicone oil injection in AIDS patients with retinal
detachment due to viral retinitis. Methods: A consecutive series of 83 eyes in 75 AIDS patients who were
treated with vitrectomy and silicone oil for retinal detachment due to viral retinitis was studied
prospectively and followed until the last patient in the series had died. Design: Median postoperative
survival was 6 months, but 20% of patients survived 12 months or more. Whereas best corrected visual

acuity was 20/100 or better in over half the patients 1-2 months after operation, there was a distressing
decrease in acuity by 6 months, owing to a variety of factors. Patients operated on before macular