Parkhouse R M, Harrison L J
National Institute for Medical Research, Mill Hill, London.
Parasitology. 1989;99 Suppl:S5-19. doi: 10.1017/s0031182000083384.
A thorough study of parasitic helminth antigens is a pre-requisite for control programmes based on accurate immunochemical diagnosis, protection by vaccination and perhaps immune modulation to diminish pathological sequelae. Studies should be directed at the identification of those stage- or age-specific surface, secreted and somatic antigens which are involved in the host-parasite interactions responsible for immunity and/or pathology. Current methods of diagnosis of parasitic infections often fail to detect low-level patent infections, which incurs the risk of having a reservoir capable of perpetuating infections. There is, then, an urgent requirement for accurate immunochemical diagnosis, to be used in association with, and for the evaluation of, drug treatment and vector elimination, in parasite control programmes. Given the high sensitivity of current immunoassay technology, the only bar to establishing the necessary immunological tests is the choice of suitably specific antigen/antibody systems. Assays designed to detect parasite products or antigens are a major priority, as they indicate current infection, whereas those which detect antibody only indicate exposure to infection, which may or may not be current. Surface and secreted antigens are the most likely targets for protective immune responses and thus form a logical focus for vaccine design. The cestodes, which present such strong evidence for immunity following natural infection, are likely to yield effective vaccines by modern procedures. Certain antigens must, however, stimulate the humoral and/or cellular responses which are responsible for the undesirable immunopathological consequences of many helminthic diseases. The nematodes and trematodes furnish some extreme examples of such pathology. The ultimate objective in identifying these particular antigens is to utilize them in the appropriate down-regulation of the immune response responsible for such pathology. As an illustration, we have presented an interesting correlation between one particular clinical condition of onchocerciasis (Sowda) and the serological response, defined both in terms of the parasite antigens and an immunoglobulin class-restricted antibody response. Finally, the complexity of these parasite systems and the host response to the parasite should not be underestimated. Modern analytical techniques allow their detailed analysis in terms of the humoral antibody responses and afford the possibility of the future development of control and disease management procedures tailored to each individual host-parasite system. However, novel systems are required to complete the analysis of the cellular components of the immune response to parasite antigens, and functional studies are needed to determine the role that these parasite antigens play in the complex interaction between parasite and host.
对寄生蠕虫抗原进行全面研究，是基于准确免疫化学诊断、疫苗接种保护以及或许通过免疫调节来减轻病理后遗症的防治计划的先决条件。研究应致力于鉴定那些阶段或年龄特异性的表面、分泌和体细胞抗原，它们参与了宿主与寄生虫之间导致免疫和/或病理的相互作用。目前寄生虫感染的诊断方法常常无法检测到低水平的显性感染，这就带来了存在能够使感染持续存在的储存宿主的风险。因此，在寄生虫防治计划中，迫切需要准确的免疫化学诊断方法，用于配合药物治疗和消除传播媒介，并对其进行评估。鉴于当前免疫测定技术的高灵敏度，建立必要免疫检测的唯一障碍是选择合适的特异性抗原/抗体系统。旨在检测寄生虫产物或抗原的检测方法是首要重点，因为它们表明当前感染，而那些仅检测抗体的方法仅表明接触过感染，可能是当前感染，也可能不是。表面和分泌抗原最有可能是保护性免疫反应的靶点，因此是疫苗设计的合理重点。绦虫在自然感染后呈现出如此强有力的免疫证据，很可能通过现代方法产生有效的疫苗。然而，某些抗原必须刺激导致许多蠕虫病不良免疫病理后果的体液和/或细胞反应。线虫和吸虫提供了这种病理的一些极端例子。鉴定这些特定抗原的最终目标是利用它们适当地下调导致这种病理的免疫反应。作为一个例子，我们展示了盘尾丝虫病的一种特定临床状况（索瓦达病）与血清学反应之间有趣的相关性，这是根据寄生虫抗原和免疫球蛋白类别受限的抗体反应来定义的。最后，这些寄生虫系统以及宿主对寄生虫的反应的复杂性不应被低估。现代分析技术允许根据体液抗体反应对其进行详细分析，并为未来开发针对每个宿主 - 寄生虫系统量身定制的控制和疾病管理程序提供了可能性。然而，需要新的系统来完成对寄生虫抗原免疫反应细胞成分的分析，并且需要进行功能研究来确定这些寄生虫抗原在寄生虫与宿主复杂相互作用中所起的作用。
