Mycoplasma pneumoniae (Mp) is a highly contagious respiratory pathogen responsible for human community-acquired pneumonia. The number of antibiotic-resistant Mp strains is increasing; therefore, to develop novel therapeutics, it is crucial to precisely understand the pathogenesis of mycoplasma pneumonia. Herein, we examined the susceptibility and response to Mp among eight inbred mouse strains. Following infection, the bacterial load in the bronchoalveolar lavage fluid (BALF) from DBA/2 mice was higher than that in the other tested strains such as BALB/c mice, which are frequently used in Mp research. In contrast, the numbers of CD45⁺ immune cells and neutrophils in BALF were comparable between BALB/c and DBA/2 mice, with lower numbers observed in C57BL/6J and CBA/N mice than in BALB/c mice. Among the tested strains, the BALF level of interleukin 12 subunit p40 was highest in DBA/2 mice; however, significant differences in other cytokines levels were not observed between BALB/c and DBA/2 mice. After Mp infection, Mp-specific Th1 and Th17 responses were significantly enhanced in DBA/2 mice when compared with BALB/c mice. Furthermore, prior infection with Mp increased the number of neutrophils in BALF after the reinfection of DBA/2 mice through an Mp-specific CD4⁺ T cell-dependent mechanism. Thus, DBA/2 may be an appropriate strain for evaluating Mp infection. Moreover, a comparison of responses revealed by various inbred mouse strains could be useful for elucidating the pathogenesis of Mycoplasma pneumonia.

肺炎支原体（Mp）是高度传染性的呼吸道病原体，负责人类社区获得性肺炎。耐抗生素的Mp菌株的数量正在增加。因此，开发新的疗法，准确了解支原体肺炎的发病机制至关重要。在这里，我们检查了八个自交系小鼠品系中对Mp的敏感性和反应性。感染后，来自DBA / 2小鼠的支气管肺泡灌洗液（BALF）中的细菌载量高于其他测试菌株（例如BALB / c小鼠）中的细菌载量，后者经常用于Mp研究中。相比之下，CD45 ⁺BALF / c和DBA / 2小鼠之间BALF中的免疫细胞和中性粒细胞相当，在C57BL / 6J和CBA / N小鼠中观察到的数量低于BALB / c小鼠。在所测试的菌株中，白介素12亚基p40的BALF水平在DBA / 2小鼠中最高。但是，在BALB / c和DBA / 2小鼠之间未观察到其他细胞因子水平的显着差异。Mp感染后，与BALB / c小鼠相比，DBA / 2小鼠的Mp特异性Th1和Th17反应显着增强。此外，通过Mp特异性CD4 ^+重新感染DBA / 2小鼠后，先前感染Mp会增加BALF中嗜中性粒细胞的数量T细胞依赖性机制。因此，DBA / 2可能是评估Mp感染的合适菌株。此外，各种近交小鼠品系揭示的反应比较可能有助于阐明支原体肺炎的发病机理。