AIDSWEEKLY Plus; Monday, September 7 & 14, 1998
Daniel J. DeNoon, Senior Editor
Researchers Rigmor Thorstensson and colleagues expected to find that vaccines capable of protecting monkeys against intrarectal challenge with pathogenic simian immunodeficiency virus (SIV) would stimulate beta chemokine production.
The beta chemokines (RANTES, MIP-1(alpha), and MIP-1(beta)) are the natural ligands for the CCR5 receptor used for cell entry by the great majority of infectious HIV strain. High beta-chemokine levels are associated with protection against HIV infection and disease.
But they obtained different results than anticipated.
"The level of RANTES was significantly higher in protected animals then in infected animals," Thorstensson said. "Even more interesting was that the level of RANTES before immunization was higher in the protected versus the infected animals. Actually, we could see very little effect of vaccination on RANTES production."
Similarly significant results were seen for MIP-1(alpha), although there was merely a nonsignificant trend in that direction for MIP- 1(beta).
The researchers subjected the animals to the rigorous challenge protocol after immunizing them with one of two different vaccines. Six of the cynomolgus macaques received attenuated SIVmacC8; four others received the chimeric SHIV-4 vaccine. Eight to 16 months later - when all animals had become vaccine-virus isolation negative but PCR positive - they administered 10 median infectious doses of the heterologous, pathogenic SIVsm via rectum.
Three of the SIVmac and one of SHIV recipients were completely protected against infection, while one from each group showed limited challenge-virus replication for the first month and none thereafter. These six animals were considered protected; the four other animals and all 10 control animals became persistently infected with SIVsm.
Thorstensson concluded that genetic or environmental factors may influence whether an individual has high beta-chemokine levels.
"We do not think that beta chemokines can protect against high- dose intrarectal challenge, but we think that they have a synergistic effect with the vaccine," he said.
980907
AW980902
Copyright © 1998 - Charles Henderson, Publisher. All rights Reserved. Permission to reproduce granted to AEGIS by Charles W. Henderson. Authorization to reproduce for personal use granted granted by C. W. Henderson, Publisher, provided that the fee of US$4.50 per copy, per page is paid directly to the Copyright Clearance Center, 27 Congress Street, Salem, Massachusetts 01970, USA.
Published by Charles Henderson, Publisher. Editorial & Publishing Office: P.O. Box 5528, Atlanta, GA 30307-0528 / Telephone: (800) 633-4931; Subscription Office: P.O. Box 830409, Birmingham, AL 35283-0409 / FAX: (205) 995-1588 http://www.newsfile.com
AEGiS is made possible through unrestricted grants from Boehringer Ingelheim, iMetrikus, Inc., the National Library of Medicine, and donations from users like you. Always watch for outdated information. This article first appeared in 1998. This material is designed to support, not replace, the relationship that exists between you and your doctor.
AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.
Copyright ©1980, 1998. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .