来自法国的一组科学家在4月9日表示，他们期望能通过对一小部分未接受治疗而能长时间对抗体内HIV病毒的病人的研究来寻找到一种艾滋病疫苗。
法国国家艾滋病研究机构的主任Jean-Francois Delfraissy表示：“有很小一部分的艾滋病人——大约少于艾滋病人总数的1%——能在其免疫系统内部产生非常强大的抗病毒反应，这正是我们期望能从疫苗中获得的效果。”
Delfraissy和其他研究人员正在致力于研究这些HIV携带者是如何有效控制体内的病毒的。他们的研究结果发表在美国刊物《美国国家科学院院刊》（PNAS）上，文章说明了一些被称为CD8的免疫细胞是如何帮助这一小部分病人阻止HIV感染的传播过程的。
这些病人虽然有很强的免疫力，但是他们仍然呈HIV阳性，因为其体内还是在源源不断的产生对抗HIV的抗体，但是他们并不需要进行治疗。
因此科学家们表示，CD8细胞在这一过程中起到的关键作用能帮助寻找到一种疫苗，一种针对大部分免疫系统无法自发激活强大的抗HIV机制的病人的疫苗。
由于变异的非常快，而且有很多对抗抗体的手段，HIV是疫苗研究人员遇到过的最可怕的敌人。但是就在今年2月，一个美国研究小组表示他们找到了在HIV病毒上存在一个关键的不变区域——这意味着他们找到了一个不变的攻击目标。该小组还说在一些体内长期存在病毒的人血液中找到了能识别这一区域的特殊抗体——b12。
原始出处：http://www.physorg.com/news95359489.html
部分英文原文：
Published online before print April 11, 2007
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0611244104
Immunology
HIV controllers exhibit potent CD8 T cell capacity to suppress HIV infection ex vivo and peculiar cytotoxic T lymphocyte activation phenotype
( HIV suppression | CD8+ T cells | HLA-DR | CD38 )
Asier Sáez-Cirión , Christine Lacabaratz , Olivier Lambotte , Pierre Versmisse , Alejandra Urrutia , Faroudy Boufassa ¶, Françoise Barré-Sinoussi , Jean-François Delfraissy , Martine Sinet , Gianfranco Pancino ||, Alain Venet , and for the Agence Nationale de Recherches sur le Sida EP36 HIV Controllers Study Group
Unité de Régulation des Infections Rétrovirales, Institut Pasteur, 75725 Paris, France; Unité 802, Institut National de la Santé et de la Recherche Médicale, Faculté de Médecine Paris XI, 94276 Le Kremlin-Bicêtre, France; and Service de Médecine Interne et Maladies Infectieuses and ¶Unité 569, Institut National de la Santé et de la Recherche Médicale/Institut National des Etudes Démographiques, Hôpital Bicêtre, 94276 Le Kremlin-Bicêtre, France
Edited by Dan R. Littman, New York University Medical Center, New York, NY, and approved February 27, 2007 (received for review December 18, 2006)
Some rare HIV-1-infected individuals, referred to as HIV controllers (HIC), have persistently undetectable plasma viral load in the absence of therapy. This control of HIV-1 replication has been associated with a strong, multifunctional specific CD8+ T cell response. However, no direct link between this immune response and the control of viremia has so far been provided. We investigated parameters of specific CD8+ T cell response and in vitro susceptibility to HIV-1 infection in 11 HIC. We found high frequencies of HIV-specific CD8+ T cells. Interestingly, these cells expressed the activation marker HLA-DR but not CD38. This unique phenotype differentiates HIV-specific CD8+ T cells from HIC and noncontroller subjects and likely reflects a high potential to expand upon exposure to antigen and a capacity to exert effector functions. Accordingly, although CD4+ T cells from HIC were fully susceptible to HIV-1 superinfection, their CD8+ T cells effectively suppressed HIV-1 infection. Remarkably, this potent anti-HIV activity was observed without prior stimulation of CD8+ T cells. This activity was not mediated by secreted inhibitory factors but was due to the elimination of infected CD4+ T cells and was observed only with autologous CD4+ T cells, indicating an HLA-restricted cytotoxic mechanism. This constitutive antiviral capacity of CD8+ T cells could account for the control of viral replication in HIC.
