PDF(Pubmed)
Abstract：
The immune memory is one of the defensive strategies developed by both unicellular and multicellular organisms for ensuring their integrity and functionality. While the immune memory of the vertebrate adaptive immune system (based on somatic recombination) is antigen-specific, encompassing the generation of memory T and B cells that only recognize/react to a specific antigen epitope, the capacity of vertebrate innate cells to remember past events is a mostly non-specific mechanism of adaptation. This \"innate memory\" can be considered as germline-encoded because its effector tools (such as innate receptors) do not need somatic recombination for being active. Also, in several organisms the memory-related information is integrated in the genome of germline cells and can be transmitted to the progeny for several generations, but it can also be erased depending on the environmental conditions. Overall, depending on the organism, its environment and its living habits, innate immune memory appears to be a mechanism for achieving better protection and survival against repeated exposure to microbes/stressful agents present in the same environment or occurring in the same anatomical district, able to adapt to changes in the environmental cues. The anatomical and functional complexity of the organism and its lifespan drive the generation of different immune memory mechanisms, for optimal adaptation to changes in the living/environmental conditions. The concept of innate immunity being non-specific needs to be revisited, as a wealth of evidence suggests a significant degree of specificity both in the primary immune reaction and in the ensuing memory-like responses. This is clearly evident in invertebrate metazoans, in which distinct scenarios can be observed, with both non-specific (immune enhancement) or specific (immune priming) memory-like responses. In the case of mammals, there is evidence that some degree of specificity can be attained in different situations, for instance as organ-specific protection rather than microorganism-specific reaction. Thus, depending on the challenges and conditions, innate memory can be non-specific or specific, can be integrated in the germline and transmitted to the progeny or be short-lived, thereby representing an exceptionally plastic mechanism of defensive adaptation for ensuring individual and species survival.
摘要：
免疫记忆是单细胞和多细胞生物体为确保其完整性和功能而开发的防御策略之一。虽然脊椎动物适应性免疫系统的免疫记忆（基于体细胞重组）是抗原特异性的，包括仅识别/反应特定抗原表位的记忆T和B细胞的产生，脊椎动物先天细胞记忆过去事件的能力是一种非特异性的适应机制。这种“先天记忆”可以被认为是种系编码的，因为它的效应工具（如先天受体）不需要体细胞重组就可以激活。此外，在几种生物体中，与记忆相关的信息被整合到种系细胞的基因组中，并可以传递给后代几代，但也可以根据环境条件擦除。总的来说,取决于有机体，它的环境和生活习惯，先天免疫记忆似乎是一种机制，可以更好地保护和生存，防止反复暴露于同一环境中或同一解剖区域中存在的微生物/应激因子。能够适应环境线索的变化。生物体的解剖和功能复杂性及其寿命驱动着不同免疫记忆机制的产生，以最佳方式适应生活/环境条件的变化。先天免疫是非特异性的概念需要重新审视，大量证据表明，在初次免疫反应和随后的记忆样反应中均具有显着的特异性。这在无脊椎动物后生动物中非常明显，可以观察到不同的场景，具有非特异性（免疫增强）或特异性（免疫启动）记忆样反应。就哺乳动物而言，有证据表明，在不同的情况下可以达到一定程度的特异性，例如作为器官特异性保护而不是微生物特异性反应。因此，根据挑战和条件，先天记忆可以是非特异性的或特异性的，可以整合到种系中并传播给后代或短命，从而代表了确保个体和物种生存的防御性适应的异常可塑性机制。
