Pulmonary granulomas are widely considered the epicenters of the immune response to Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). Recent animal studies have revealed factors that either promote or restrict TB immunity within granulomas. These models, however, typically ignore the impact of preexisting immunity on cellular organization and function, an important consideration because most TB probably occurs through reinfection of previously exposed individuals. Human postmortem research from the pre-antibiotic era showed that infections in Mtb-naïve individuals (primary TB) versus those with prior Mtb exposure (postprimary TB) have distinct pathologic features. We review recent animal findings in TB granuloma biology, which largely reflect primary TB. We also discuss our current understanding of postprimary TB lesions, about which much less is known. Many knowledge gaps remain, particularly regarding how preexisting immunity shapes granuloma structure and local immune responses at Mtb infection sites.

中文翻译：

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结核性肉芽肿和已有的免疫力


肺肉芽肿被广泛认为是对结核分枝杆菌（Mtb）（结核病（TB）的病原体）免疫反应的中心。最近的动物研究揭示了促进或限制肉芽肿内结核免疫的因素。然而，这些模型通常忽略了先前存在的免疫力对细胞组织和功能的影响，这是一个重要的考虑因素，因为大多数结核病可能是通过先前暴露的个体的再感染而发生的。前抗生素时代的人类尸检研究表明，未接触过结核分枝杆菌的个体（原发性结核病）与先前接触过结核分枝杆菌的个体（原发性结核病）的感染具有不同的病理特征。我们回顾了结核肉芽肿生物学的最新动物发现，这在很大程度上反映了原发性结核。我们还讨论了我们目前对原发性结核病病变的理解，对此知之甚少。仍然存在许多知识空白，特别是关于先前存在的免疫如何塑造结核分枝杆菌感染部位的肉芽肿结构和局部免疫反应。