Utilising proteomics to develop anti-HCMV immunotherapy

人类巨细胞病毒（HCMV）是一种疱疹病毒，几乎感染全世界所有人。感染是终生的，在此期间由免疫系统控制。虽然大多数感染不会引起症状，但HCMV仍然是某些人群疾病的主要原因。如果在怀孕期间被感染，这种病毒会传给胎儿，导致耳聋、智力迟钝，甚至胎儿死亡。在英国，每年有多达1000名婴儿因HCMV而导致严重的永久性残疾，比唐氏综合症或胎儿酒精综合症还要多。HCMV是免疫系统较差的个体，特别是移植患者和艾滋病毒/艾滋病患者中严重危及生命的疾病的主要原因。HCMV还与最常见的脑癌、动脉硬化、免疫系统早衰、肝炎和炎症性肠病有关。抗病毒药物有毒副作用，病毒很快就会对它们产生抗药性。迫切需要更好的治疗选择。巨细胞病毒是最复杂的人类病毒。不幸的是，我们和其他人已经证明，只要病毒在实验室中生长，它就会发生变化。这意味着研究人员无法研究导致临床疾病的实际病毒，这限制了疫苗和治疗方法的发展。为了解决这个问题，我们提取了一种临床病毒，对其基因组进行了测序，并将其命名为梅林菌株。这已被采纳为全球HCMV参考菌株。我的工作描述了这种病毒在实验室中生长时的变化，并使我能够设计出一种独特的系统来阻止这些变化的发生。科学家们第一次可以用一种精确模仿致病病毒的病毒进行实验。我现在将使用这种病毒，连同最先进的技术，来确定所有可用于疫苗接种或治疗的HCMV蛋白。迄今为止，疫苗的目的是预防病毒的初次感染。这些研究需要针对病毒中存在的蛋白质，但临床病毒中存在的整套蛋白质是完全未知的。利用我们的病毒，我们现在可以定义完整的可用于靶向的蛋白质。尽管这些疫苗策略可以减少感染的机会，但它们不能完全阻止感染。一旦一个人被感染，就需要一种不同的策略——一种在被感染后杀死细胞的策略。免疫系统只有在能够识别被感染细胞的情况下才能杀死它们，但我们不知道病毒是如何改变被感染细胞的。使用我们最先进的技术和病毒，我们现在将确定HCMV如何改变感染细胞的表面。我们将确定这些变化中的哪些是杀死受感染细胞的最佳靶点，并设计可以给予患者的抗体，使他们的免疫系统能够识别这些细胞，并杀死它们——从而控制HCMV感染。虽然我们在开发和测试这些针对感染细胞的治疗试剂方面处于独特的地位，但我们的新病毒仍然受到限制。病毒通过体液（如尿液、唾液）的分泌自然传播。为了了解和控制病毒在人与人之间传播的过程，我们必须能够在实验室中模拟这一过程。然而，当我们在实验室中培养临床病毒时，分泌的病毒很少。我们已经证明这是因为一种叫做RL13的病毒基因。我们将研究RL13如何阻止病毒的分泌，如何在实验室中绕过它，以及当病毒在患者体内分泌时如何绕过它。这将使生产大量的分泌病毒，尽可能接近患者分泌的病毒。这对于使实验室能够调查HCMV在人与人之间传播的方式以及开发阻止这种情况发生的方法至关重要。

Human cytomegalovirus (HCMV) is a herpesvirus that infects almost everyone worldwide. Infection is lifelong, during which time it is controlled by the immune system. While the majority of infections do not cause symptoms, HCMV is nevertheless a major cause of disease in certain groups of people. If caught during pregnancy, the virus can pass to the foetus and can result in deafness, mental retardation, or even death of the unborn child. In the UK up to 1000 babies per year have severe permanent disabilities due to HCMV, more than Down's syndrome or foetal alcohol syndrome. HCMV is a major cause of severe life-threatening disease in individuals with poor immune systems, notably transplant patients and people with HIV/AIDs. HCMV has also been associated with the most common form of brain cancer, hardening of the arteries, premature aging of the immune system, hepatitis and inflammatory bowel problems. Antiviral drugs have toxic side effects, and viruses rapidly become resistant to them. There is an urgent need for better therapeutic options.CMV is the most complex human virus. Unfortunately we, and others, have shown that the virus changes whenever it is grown in the laboratory. This means that researchers have not been able to study the actual virus that causes clinical disease, and this has limited the development of vaccines and therapy. To solve this problem we took a clinical virus, sequenced its genome and designated it strain Merlin. This has been adopted as the worldwide HCMV reference strain. My work has characterised how this virus changes when grown in the lab and enabled me to devise a unique system to stop these changes happening. For the first time, scientists can perform experiments with a virus that accurately mimics the virus that causes disease. I will now use this virus, along with state-of-the-art technology, to define all HCMV proteins that can be targeted for vaccination or therapy.To date vaccines have aimed to prevent initial infection with the virus. These studies need to target proteins present in the virus, yet the entire set of proteins present in clinical virus is completely unknown. Using our viruses we can now define the complete set of proteins available for targeting.Although these vaccine strategies may reduce the chances of becoming infected, they cannot stop infection completely. Once a person is infected, a different strategy is required - one that enables cells to be killed after they are infected. The immune system can only kill infected cells if it can recognise them, yet we don't know how the virus changes infected cells. Using our state-of-the-art techniques and viruses, we will now determine exactly how HCMV changes the surface of an infected cell. We will determine which of these changes are the best targets for killing infected cells, and engineer antibodies that can be given to patients to enable their immune system to recognise these cells, and kill them - thereby controlling the HCMV infection.Although we are in a unique position to develop and test these therapeutic reagents against infected cells, our novel viruses still suffer from a limitation. Virus is naturally spread by being secreted in bodily fluids (e.g. urine, saliva). To understand and control the process by which the virus spreads between people, we must be able to mimic this process in the lab. Yet when we grow clinical virus in the lab, very little virus is secreted. We have shown that this is because of a viral gene called RL13. We will investigate how RL13 stops secretion of virus, how this can be circumvented in the lab, and how it is circumvented when virus is secreted in patients. This will enable the production of large amounts of secreted virus that, as closely as possible, represents virus secreted from patients. This is crucial to enable laboratories to investigate the way HCMV spreads between people, and to develop ways of stopping it happening.