Abstract |
The acquired immune deficiency syndrome (AIDS) is the great epidemic of our times, with 65 million people infected, 35 million already died and 15,000 people infected every day. The most rational strategy for coping with the disease is to develop a preventive vaccine, however developing such a vaccine requires sufficient knowledge of the pathogenesis of the disease. Although we know the biology of the virus that causes AIDS, our information on how the virus causing the disease is limited. The problem that makes the issue of pathogenesis more much complex is that the majority of the cell population that is depleted by the
presence of the virus in the body of the host is not infected. The prevailing view
today is that the virus sensitizes the apoptotic pathways of these cells and leads them to programmed death. The main cell population affected by infection with HIV-1 belongs to the CD4+ T lymphocytes. The principal functional role of such
cells is to interact with cells "professional antigen-presenters" such as macrophages and mediate the secretion of cytokines and other factors in regulating the type of immune response (humoral or cytotoxic). Our research group has recently shown that components of the virus (and not necessarily the whole virus) cause a specific effect on antigen-presentation characterized by an increased activation of CD4+ T cells respond to antigenic stimulus, which then go
to apoptosis. This phenomenon is prevented when the macrophages were exposed to synthetic peptides of the virus. The presence of viral components, such as glycoprotein gp120 on the surface of infected macrophages, impede the
physiological mechanism of antigen-presentation through the interplay of the V3 region of gp120 with the amino-terminal region of CCR5 of the responsive CD4+ T lymphocyte. This interaction is purely ionic in nature and intensity of the reaction is directly related to the number of basic amino acids in the V3 region.
The main objective of this work was to study the physicochemical properties of
V3 synthetic peptides involved in the interaction with CCR5 by Laser light
scattering spectroscopy. We analyzed the behavior of these peptides in
physiological solutions and the influence of ionic forces / interactions as a function of the number of basic amino acids in the V3 region.
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