传统上,成功的疫苗依赖于特异性适应性免疫,通过用减毒的病原体激活淋巴细胞,或病原体亚基,在随后的暴露中引发更高的反应。然而,最近关于结核分枝杆菌和其他病原体的研究已经确定了“训练过的”单核细胞通过记忆样但非特异性免疫在保护中的作用。这里,我们使用体外共培养的方法来研究训练有素的巨噬细胞的潜在作用,包括肺泡巨噬细胞,在对土伦弗朗西斯菌活疫苗株(LVS)的免疫反应中。F.tularensis是一种在哺乳动物巨噬细胞内复制并引起呼吸道和全身性疾病的细胞内细菌。我们用F.tularensisLVS接种小鼠,然后获得肺泡巨噬细胞,或者来源于骨髓的巨噬细胞.LVS在两种类型的巨噬细胞中感染和复制,无论是幼稚的还是接种LVS的小鼠。然后将LVS感染的巨噬细胞与初始脾细胞共培养,皮内接种小鼠的脾细胞,或静脉接种小鼠的脾细胞。第一次,我们显示免疫(但不是幼稚)脾细胞控制肺泡巨噬细胞内的细菌复制,与以前使用骨髓源性巨噬细胞的结果相似。然而,在与未接种LVS疫苗的小鼠的初始巨噬细胞或巨噬细胞的共培养物之间,对营养内细菌复制的控制没有差异;此外,在所有条件下,上清液中的一氧化氮水平和干扰素-γ产量在很大程度上具有可比性.因此,在体外共培养的背景下,数据不支持皮内或静脉内接种LVS的小鼠的骨髓或肺中形成经过训练的巨噬细胞.
目的:在单核细胞中发现非特异性的“训练免疫”产生了巨大的兴奋。然而,到目前为止,已经对相对较少的微生物进行了培训研究(例如,牛分枝杆菌卡介苗,用作疫苗的减毒活胞内细菌)和微生物物质(例如,LPS),目前尚不清楚感染期间的训练是否常见。我们以前证明了用土伦弗朗西斯菌活疫苗株(LVS)接种小鼠,另一种活的减毒细胞内细菌,免受无关细菌单核细胞增生李斯特菌的攻击。因此,本研究测试了LVS疫苗接种是否产生有助于这种保护的训练的巨噬细胞。要做到这一点,我们使用之前的体外共培养方法与鼠骨髓来源的巨噬细胞进行扩增和研究肺泡巨噬细胞.我们证明了肺泡巨噬细胞可以被生产性感染并用于表征与LVS免疫淋巴细胞的相互作用。然而,我们发现没有证据表明骨髓源性巨噬细胞或肺泡巨噬细胞接受了LVS疫苗的训练.
Traditionally, successful vaccines rely on specific adaptive immunity by activating lymphocytes with an attenuated pathogen, or pathogen subunit, to elicit heightened responses upon subsequent exposures. However, recent work with Mycobacterium tuberculosis and other pathogens has identified a role for \"trained\" monocytes in protection through memory-like but non-specific immunity. Here, we used an in vitro co-culture approach to study the potential role of trained macrophages, including lung alveolar macrophages, in immune responses to the Live Vaccine Strain (LVS) of Francisella tularensis. F. tularensis is an intracellular bacterium that replicates within mammalian macrophages and causes respiratory as well as systemic disease. We vaccinated mice with F. tularensis LVS and then obtained lung alveolar macrophages, or derived macrophages from bone marrow. LVS infected and replicated comparably in both types of macrophages, whether naïve or from LVS-vaccinated mice. LVS-infected macrophages were then co-cultured with either naïve splenocytes, splenocytes from mice vaccinated intradermally, or splenocytes from mice vaccinated intravenously. For the first time, we show that immune (but not naïve) splenocytes controlled bacterial replication within alveolar macrophages, similar to previous results using bone marrow-derived macrophage. However, no differences in control of intramacrophage bacterial replication were found between co-cultures with naïve macrophages or macrophages from LVS-vaccinated mice; furthermore, nitric oxide levels and interferon-gamma production in supernatants were largely comparable across all conditions. Thus, in the context of in vitro co-cultures, the data do not support development of trained macrophages in bone marrow or lungs of mice vaccinated with LVS intradermally or intravenously.
OBJECTIVE: The discovery of non-specific \"trained immunity\" in monocytes has generated substantial excitement. However, to date, training has been studied with relatively few microbes (e.g., Mycobacterium bovis Bacille Calmette-Guérin, a live attenuated intracellular bacterium used as a vaccine) and microbial substances (e.g., LPS), and it remains unclear whether training during infection is common. We previously demonstrated that vaccination of mice with Francisella tularensis Live Vaccine Strain (LVS), another live attenuated intracellular bacterium, protected against challenge with the unrelated bacterium Listeria monocytogenes. The present study therefore tested whether LVS vaccination engenders trained macrophages that contributed to this protection. To do so, we used a previous in vitro co-culture approach with murine bone marrow-derived macrophages to expand and study lung alveolar macrophages. We demonstrated that alveolar macrophages can be productively infected and employed to characterize interactions with LVS-immune lymphocytes. However, we find no evidence that either bone marrow-derived or alveolar macrophages are trained by LVS vaccination.