How do lymphocyte proliferation and survival contribute to immunological memory in health, ageing and HIV infection?

免疫系统通过记忆来保护我们免受感染？我们过去遇到的感染，以阻止它们再次造成伤害。免疫系统是如何做到这一点的？它将称为淋巴细胞的细胞家族留在一边，每个细胞家族都针对一种特定的感染。矛盾的是，这些细胞似乎寿命很短(几周到几个月)，而我们知道免疫记忆可以持续几年到几十年。免疫系统必须保存这些记忆细胞家族？不知何故，但同时它必须容纳新的记忆淋巴细胞家族，因为遇到新的感染，还必须保留足够数量的细胞来对抗新的微生物。当这种保护系统失效时，问题就会出现。导致免疫系统问题的两种常见情况是老龄化和艾滋病毒感染；这两种情况都影响到我们越来越多的人口。随着我们年龄的增长，免疫系统对抗感染的能力变得越来越弱。这是由于不同存储单元家族之间的不平衡造成的。HIV感染直接损害一些免疫细胞，但也间接影响所有记忆细胞，使免疫问题变得更糟。我们仍然不知道这到底是如何发生的。这个项目通过测量人体内不同淋巴细胞家族的分裂速度和存活率来研究长期免疫记忆是如何维持的。我们将通过应用四种不同的测量来评估其中有多少是短期的、长期的和非常长期的，其中三种依赖于追踪细胞分裂速度的无害示踪剂，另一种测量人体内自然发现的放射性碳的变化量。该项目代表了五个不同中心的合作：伦敦、牛津、加的夫、斯德哥尔摩和美国国立卫生研究院。了解老年人免疫系统较弱的原因将有助于我们设计出防止这种下降的方法，并为老年人设计更好的疫苗接种计划。了解HIV感染中的免疫记忆将有助于我们想出新的方法来帮助免疫系统对抗病毒，并改善艾滋病毒/艾滋病患者的疫苗接种情况。我们的结果将通过新闻媒体广泛向公众公布，并向那些特别感兴趣的人公布，例如。那些希望确保自己随着年龄的增长保持健康的人，以及那些受艾滋病毒/艾滋病影响的人，通过专业兴趣小组和非专业出版物。

The immune system protects us from infections by ?remembering? the infections we have encountered in the past to stop them causing harm again. How does the immune system do this? It sets aside families of cells called lymphocytes, each specific for a particular infection. Paradoxically, these cells appear to be short-lived (weeks-months), whereas we know that immune memory lasts years-decades. The immune system must preserve these families of ?memory cells? somehow, but at the same time it must accommodate new families of memory lymphocytes, as new infections are encountered, and also retain sufficient numbers of cells to combat new microbes.Problems occur when this system of protection fails. Two common situations leading to problems in the immune system are ageing and HIV infection; both affect an increasing proportion of our population. As we age, the immune system becomes less able to combat infections. This results from an imbalance between different families of memory cells. HIV infection damages some immune cells directly, but it also affects all memory cells indirectly, making immune problems worse. We still do not understand how exactly this happens.This project investigates how long-term immune memory is maintained by measuring the division rate and survival of different families of lymphocytes within the human body. We will assess how many are short-lived, long-lived and very long-lived by applying four different kinds of measurement, three depending on harmless tracers given to track how fast cells divide, and one measuring changing amounts of radioactive carbon naturally found in the body. The project represents a collaboration five different centres: London, Oxford Cardiff, Stockholm and the National Institutes for Health in the USA.Understanding why the immune system is weaker in the elderly will help us devise ways to prevent this decline and design better vaccination schemes for elderly people. Understanding immune memory in HIV infection will help us think of new ways to help the immune system fight the virus and improve the use of vaccination in people with HIV/AIDS. Our results will be made widely available to the general public, through the press, and to those specifically interested, eg. those who wish to ensure they stay healthy as they age and those affected by HIV/AIDS, through specialist interest groups and lay publications.