Gordy James T, Bates Rowan E, Glass Elizabeth, Meza Jacob, Li Yangchen, Schill Courtney, Taylor Alannah D, Wang Tianyin, Chen Fengyixin, Plunkett Khaleel, Karanika Styliani, Karakousis Petros C, Markham Richard B
Johns Hopkins School of Public Health.
Johns Hopkins University School of Medicine.
Res Sq. 2025 Jan 14:rs.3.rs-5663995. doi: 10.21203/rs.3.rs-5663995/v1.
Tuberculosis (TB) remains a major cause of global morbidity and mortality. Efforts to control TB are hampered by the lengthy and cumbersome treatment required to eradicate the infection. Bacterial persistence during exposure to bactericidal antibiotics is at least partially mediated by the bacterial stringent response enzyme, Rel. A therapeutic DNA vaccine targeting Rel has been shown to increase the efficacy of antitubercular drugs, and fusing macrophage-inflammatory protein 3α (MIP-3α), which interacts with CCR6 on immature dendritic cells (iDCs), to Rel further increases the vaccine's therapeutic efficacy. A secondary analysis of these prior studies elucidated prominent sex-based differences in vaccine therapeutic efficacy, with female mice showing improved microbial outcomes compared to males as a result of the Rel and MIP-3α-Rel vaccine constructs, with a greater sex-associated difference in the MIP-3α-Rel group. In the current study, we addressed the hypothesis that these sex-related differences are due to differential DC activation/function soon after vaccination.
A EαGFP reporter vaccine model was used to track vaccine antigen presentation by an antibody Y-Ae which binds the Eα peptide tag in complex with I-A MHC-II molecules.
MIP-3α-EαGFP groups had more DCs presenting vaccine antigen infiltrating from the periphery, with more abundant Langerhans cells in males and greater CD8 + CD103 + cross-presenting dermal DCs in females. This model also shows there is greater DC activation, as measured by CD80 and MHC II MFI, by MIP-3α compared to EαGFP alone, especially in female mice.
Our findings are consistent with the sex- and MIP-3α-related differences seen in the therapeutic model and supports the hypothesis that in both sexes MIP-3α enhances vaccine uptake and cell activation by peripheral iDCs. Additionally, Female mice showed greater levels of antigen presentation, especially in DCs able to cross-present antigen, explaining why they had the best outcomes. Further studies are required to understand underlying mechanisms and to link APC results directly to T-cell responses.
结核病（TB）仍然是全球发病和死亡的主要原因。控制结核病的努力因根除感染所需的漫长而繁琐的治疗而受到阻碍。在接触杀菌抗生素期间细菌的持续存在至少部分是由细菌严格反应酶Rel介导的。一种靶向Rel的治疗性DNA疫苗已被证明可提高抗结核药物的疗效，并且将与未成熟树突状细胞（iDCs）上的CCR6相互作用的巨噬细胞炎性蛋白3α（MIP-3α）与Rel融合可进一步提高疫苗的治疗效果。对这些先前研究的二次分析阐明了疫苗治疗效果中显著的性别差异，由于Rel和MIP-3α-Rel疫苗构建体，雌性小鼠与雄性小鼠相比显示出更好的微生物学结果，在MIP-3α-Rel组中性别相关差异更大。在当前研究中，我们探讨了这些性别相关差异是由于接种疫苗后不久DC激活/功能不同的假设。
使用EαGFP报告疫苗模型通过抗体Y-Ae追踪疫苗抗原呈递，该抗体与I-A MHC-II分子复合物中的Eα肽标签结合。
MIP-3α-EαGFP组有更多从外周浸润的呈递疫苗抗原的DCs，雄性中朗格汉斯细胞更丰富，雌性中CD8 + CD103 +交叉呈递的真皮DCs更多。该模型还显示，与单独的EαGFP相比，MIP-3α通过CD80和MHC II平均荧光强度（MFI）测量的DC激活更大，尤其是在雌性小鼠中。
我们的发现与治疗模型中观察到的性别和MIP-3α相关差异一致，并支持以下假设：在两性中，MIP-3α增强外周iDCs对疫苗的摄取和细胞激活。此外，雌性小鼠显示出更高水平的抗原呈递，尤其是在能够交叉呈递抗原的DCs中，这解释了为什么它们有最好的结果。需要进一步研究以了解潜在机制并将抗原呈递细胞（APC）结果直接与T细胞反应联系起来。
