Oxidised mannan as a novel adjuvant to vaccinate against mucosal infections

大多数病原体通过粘膜表面入侵。然而，目前的疫苗是通过注射的方式提供的，在诱导粘膜免疫方面效果不佳。理想的疫苗应该包括一种确定的蛋白质抗原和一种合适的佐剂，这种佐剂可以滴鼻或口服。已经为一些感染定义了保护性抗原，但一直难以找到合适的佐剂。我们发现，甘露聚糖是一种来自酵母的复杂碳水化合物，可以氧化连接到蛋白质抗原上，作为粘膜IgA和其他类型抗体的佐剂。甘露聚糖偶联抗原滴鼻给药可显著促进小鼠血清、肺、泪液、阴道分泌物、唾液和肠道中IgA、IgG1和IgG2a的产生。我们已经对一些已知或假定的保护性抗原证实了这一点。此外，淋巴细胞反应的Th1和Th2臂都被激活。我们已经在小鼠病变模型中证明了对牙周炎(牙周炎的原因，并与早产和心血管疾病有关)的保护作用。然而，在商业利益做出承诺之前，我们需要证明对病毒感染以及肺部和肠道等其他部位的保护。已经建立了三个已被证明具有免疫球蛋白保护作用的感染模型，并可在一年内取得实际效果。1.轮状病毒是引起世界范围内人和动物严重的婴幼儿胃肠炎的主要原因。最新的(活)疫苗因副作用而被撤回。我们已经建立了猴轮状病毒在幼鼠身上引起一种急性自限性疾病的模型。成年雌性将用与灭活病毒制剂有关的甘露聚糖进行免疫，将评估对其后代的交配和被动保护。初步证据表明，轮状病毒感染与1型糖尿病的发病有关。如果这一点得到证实，将有机会测试针对糖尿病的疫苗。2.流感：用流感病毒感染小鼠是一种成熟的动物模型。小鼠将用甘露聚糖偶联从鸡蛋生长的病毒中提纯的血凝素-神经氨酸酶免疫IN。他们将受到流感病毒和肺组织匀浆中病毒滴定的挑战。将检测血清和肺冲洗液中的中和抗体。3.呼吸道合胞病毒：呼吸道合胞病毒是婴儿毛细支气管炎和肺炎的最常见原因，此前曾尝试生产疫苗，但未获成功。F和G膜糖蛋白已经被证明可以保护小鼠免受IN感染，它们将被用来偶联甘露聚糖来免疫小鼠抵抗鼻腔攻击。

Most pathogens invade via the mucosal surfaces. However, current vaccines, which are delivered by injection, are poor at inducing mucosal immunity. An ideal vaccine would comprise a defined protein antigen combined with a suitable adjuvant which could be administered intranasally or orally. Protective antigens have been defined for a number of infections but suitable adjuvants have been elusive. We showed that mannan, a complex carbohydrate from yeast, oxidatively linked to protein antigens can be used as an adjuvant for mucosal IgA and other classes of antibody. Given to mice intranasally, antigen coupled to mannan markedly enhanced production of IgA, IgG1 and IgG2a in serum, and IgA in lung, tears, vaginal secretions, saliva and gut. We have confirmed this for a number of known or putative protective antigens. In addition, both the Th1 and Th2 arms of the lymphocyte response were activated. We have demonstrated protection against P. gingivalis (cause of periodontitis and associated with premature birth and cardiovascular disease) in a mouse lesion model. However, before commercial interests will commit themselves, we need to demonstrate protection against viral infections and in other sites like lungs and gut. Three infection models where IgA has been shown to protect are already set up and can realistically produce results in 1 year. 1. Rotavirus is the major cause of severe infantile gastroenteritis in humans and animals world wide. The latest (live) vaccine was withdrawn because of side effects. We have established a model with Simian rotavirus causing an acute self-limiting disease in infant mice. Adult females will be immunised with mannan linked to killed virus preparations, mated and passive protection of their offspring will be assessed. Preliminary evidence links rotavirus infection with the onset of type 1 diabetes. If this is confirmed, there will be an opportunity to test the vaccine against diabetes. 2. Influenza: IN infection of mice with flu virus is a well established model. Mice will be immunised IN with mannan coupled to haemagglutinin-neuraminidase purified from egg-grown virus. They will be challenged IN with influenza virus and virus titrated in lung homogenates. Neutralising antibody in serum and lung washings will essayed. 3. Respiratory syncytial virus: RSV is the commonest cause of bronchiolitis and pneumonia in infants for which there have been unsuccessful attempts to produce a vaccine. F and G membrane glycoproteins have been shown to protect mice against IN infection, and they will be used coupled to mannan to vaccinate mice against intranasal challenge.