RNA processing mechanisms control lymphocyte development and activation

衰老的一个众所周知的特征是免疫系统功能下降导致对感染的易感性增加。我们的免疫系统在胎儿发育和新生儿早期形成，由包括白细胞在内的多种细胞组成。这些细胞在整个生命过程中不断地从骨髓中发现的称为造血干细胞的专门干细胞中补充。白细胞又可分为淋巴细胞和非淋巴细胞。淋巴细胞中有产生抗体的B细胞和杀死病毒感染细胞的特化细胞。在胸腺器官中发育的一类淋巴细胞被称为T细胞，这种细胞协调产生抗体和杀伤淋巴细胞的功能。淋巴细胞的一个重要特征是它们对以前的感染有记忆。这已经被用来制造疫苗，使我们对疾病免疫，而不必遭受疾病。虽然疫苗对年轻人很有效，但对老年人却效果很差，或者根本不起作用。由于淋巴细胞的重要性，人们对它们进行了大量的研究，我们对细胞发育的不同阶段有了大量的了解，这些细胞在成熟过程中经历了不同的阶段，并受到抗原的刺激（抗原是免疫学家用来形容任何刺激免疫系统的东西的技术术语）。当淋巴细胞表面的受体被触发时，我们对细胞内发生的信号传导过程了解很多。我们也很了解一类编码蛋白质的基因，称为转录因子，它在DNA中充当基因的开关。转录因子将基因DNA序列中编码的信息转化为信使rna，信使rna指定了氨基酸与蛋白质结合的顺序。我们的项目旨在了解mRNA在其产生后是如何被调节的。我们怀疑一种叫做mRNA结合蛋白的特殊蛋白质与mRNA发生物理相互作用，并控制mRNA在细胞中停留的时间和产生新蛋白质的速度。这种类型的调节被称为转录后控制，人们对其知之甚少。我们的研究将探讨这些mRNA结合蛋白在淋巴细胞中的功能，并揭示它们是如何工作的。我们的目标是了解mRNA结合蛋白如何与信号通路相互作用，最终与转录因子相互作用，以控制淋巴细胞和免疫反应。

One of the well recognised features of ageing is an increased susceptibility to infection that is caused by a decline in the function of the immune system. Our immune system forms during foetal development and the early neonatal period and is made up of many types of cells including the white blood cells. These are continuously replenished throughout the life-course from specialised stem cells called haematopoietic stem cells that are found in the bone marrow. The white blood cells can be further divided into lymphocytes and non lymphocytes. Amongst the lymphocytes are B cells which produce antibodies and specialised cells that kill virally infected cells. A class of lymphocyte that develops in an organ called the thymus is called the T cell and this cell co-ordinates the function of antibody producing and killer lymphocytes. One important feature of lymphocytes is that they hold a memory of previous encounters with infections. This has been used to create vaccines which make us immune to diseases without having to suffer the disease. While vaccines work well in young individuals they work poorly, or not at all, in the elderly. Because of the importance of lymphocytes they have been much studied and we have plenty of information on the different stages of development the cells go through as they mature and become stimulated by encounter with antigen (the technical term immunologists use for anything that stimulates the immune system). We know much about the signalling processes that take place inside the cell when receptors on the surface of lymphocytes are triggered. We also know much about a class of genes that encode proteins, called transcription factors, which act as on/off switches for genes in the DNA. Transcription factors convert the information encoded in the DNA sequence of genes into a message, called mRNA, which specifies the order in which amino acids are incorporated into proteins. Our project is aimed at understanding how the mRNA is regulated subsequent to its production. We suspect special proteins, called mRNA binding proteins, physically interact with the mRNA and control how long it remains in the cell and the rate at which it can give rise to new proteins. This type of regulation is called post-transcriptional control and is far less well understood. Our study will ask what the function of these mRNA binding proteins is in lymphocytes and will reveal how they work. Our gaol is to understand how mRNA binding proteins interact with signalling pathways and ultimately with transcription factors to control lymphocytes and the immune response.