Meng Chuang, Liu Jun, Kang Xilong, Xu Zhengzhong, Xu Shuangyuan, Li Xin, Pan Zhiming, Chen Xiang, Jiao Xinan
Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China.
Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, China.
Trop Med Infect Dis. 2023 Feb 25;8(3):140. doi: 10.3390/tropicalmed8030140.
Tuberculosis (TB), a zoonosis characterized by chronic respiratory infections, is mainly caused by and is associated with one of the heaviest disease burdens in the world. Dendritic cells (DCs) play a key role and act as a bridge between innate and adaptive immune responses against TB. DCs are divided into distinct subsets. Currently, the response of DCs to mycobacterial infections is poorly understood. Herein, we aimed to evaluate the responses of splenic conventional DCs (cDC) and plasmacytoid DCs (pDC), subsets to Bacillus Calmette-Guérin (BCG) infection in mice. Splenic pDC had a significantly higher infection rate and intracellular bacterial count than cDC and the CD8 and CD8 cDC subsets after BCG infection. However, the expression levels of CD40, CD80, CD86, and MHC-II molecules were significantly upregulated in splenic cDC and the CD8 cDC subsets compared to pDC during BCG infection. Splenic cDC had a higher expression of IFN-γ and IL-12p70 than pDC, whereas pDC had higher levels of TNF-α and MCP-1 than cDC in mice infected with BCG. At early stages of immunization with BCG containing the Ag85A protein, splenic cDC and pDC could present the Ag85A peptide to a specific T hybridoma; however, cDC had a stronger antigen presenting activity than pDC. In summary, splenic cDC and pDC extensively participate in mouse immune responses against BCG infection in vivo. Although pDC had a higher BCG uptake, cDC induced stronger immunological effects, including activation and maturation, cytokine production, and antigen presentation.
结核病（TB）是一种以慢性呼吸道感染为特征的人畜共患病，主要由结核分枝杆菌引起，是世界上疾病负担最沉重的疾病之一。树突状细胞（DCs）发挥关键作用，是针对结核病的固有免疫和适应性免疫反应之间的桥梁。DCs分为不同的亚群。目前，人们对DCs对分枝杆菌感染的反应了解甚少。在此，我们旨在评估小鼠脾脏常规DCs（cDC）和浆细胞样DCs（pDC）亚群对卡介苗（BCG）感染的反应。卡介苗感染后，脾脏pDC的感染率和细胞内细菌计数显著高于cDC以及CD8和CD8+cDC亚群。然而，在卡介苗感染期间，与pDC相比，脾脏cDC和CD8+cDC亚群中CD40、CD80、CD86和MHC-II分子的表达水平显著上调。在感染卡介苗的小鼠中，脾脏cDC的IFN-γ和IL-12p70表达高于pDC，而pDC的TNF-α和MCP-1水平高于cDC。在用含Ag85A蛋白的卡介苗免疫的早期阶段，脾脏cDC和pDC能够将Ag85A肽呈递给特异性T杂交瘤；然而，cDC的抗原呈递活性比pDC更强。总之，脾脏cDC和pDC广泛参与小鼠体内针对卡介苗感染的免疫反应。虽然pDC对卡介苗的摄取更高，但cDC诱导更强的免疫效应，包括激活和成熟、细胞因子产生以及抗原呈递。
