The immune system is a fascinating world of cells, soluble factors, interacting cells, and tissues, all of which are interconnected. The highly complex nature of the immune system makes it difficult to view it as a whole, but researchers are now trying to put all the pieces of the puzzle together to obtain a more complete picture. The development of new specialized equipment and immunological techniques, genetic approaches, animal models, and a long list of monoclonal antibodies, among many other factors, are improving our knowledge of this sophisticated system. The different types of cell subsets, soluble factors, membrane molecules, and cell functionalities are some aspects that we are starting to understand, together with their roles in health, aging, and illness. This knowledge is filling many of the gaps, and in some cases, it has led to changes in our previous assumptions; e.g., adaptive immune cells were previously thought to be unique memory cells until trained innate immunity was observed, and several innate immune cells with features similar to those of cytokine-secreting T cells have been discovered. Moreover, we have improved our knowledge not only regarding immune-mediated illnesses and how the immune system works and interacts with other systems and components (such as the microbiome) but also in terms of ways to manipulate this system through immunotherapy. The development of different types of immunotherapies, including vaccines (prophylactic and therapeutic), and the use of pathogens, monoclonal antibodies, recombinant proteins, cytokines, and cellular immunotherapies, are changing the way in which we approach many diseases, especially cancer.

免疫系统是一个由细胞、可溶性因子、相互作用的细胞和组织组成的迷人世界，所有这些都是相互关联的。免疫系统的高度复杂性使得人们很难将其视为一个整体，但研究人员现在正试图将拼图的所有部分放在一起，以获得更完整的图片。新的专用设备和免疫学技术、遗传方法、动物模型和一长串单克隆抗体的发展以及许多其他因素正在提高我们对这一复杂系统的了解。我们开始了解不同类型的细胞亚群、可溶性因子、膜分子和细胞功能，以及它们在健康、衰老和疾病中的作用。这些知识正在填补许多空白，在某些情况下，它导致我们之前的假设发生变化；例如，适应性免疫细胞以前被认为是独特的记忆细胞，直到观察到训练有素的先天免疫，并且已经发现了几种具有与细胞因子分泌T细胞相似的特征的先天免疫细胞。此外，我们不仅提高了关于免疫介导的疾病以及免疫系统如何工作以及与其他系统和成分（例如微生物组）相互作用的知识，而且还提高了通过免疫疗法操纵该系统的方法的知识。不同类型免疫疗法的发展，包括疫苗（预防性和治疗性），以及病原体、单克隆抗体、重组蛋白、细胞因子和细胞免疫疗法的使用，正在改变我们治疗许多疾病，尤其是癌症的方式。