Dynamism of immune cells in immune-tissue formation

本研究旨在揭示免疫细胞亚群通过趋化因子的动态转运形成免疫组织以响应病原体感染的规律。结果，我们发现了以下几点。1.髓系树突状细胞(MDCs)捕获和处理抗原，将其从组织中转运到引流淋巴结(LNS)并作为抗原提呈细胞，而浆细胞样树突状细胞(PDCs)通过HEV直接迁移到炎症LNS中，帮助MDCS2的APC功能。nTreg通过HEV以CCR7依赖的方式回到周围LNS的皮质旁区域，并与DCs亚群聚集。在再次挑战时，先前存在的记忆T细胞的VB使用和T细胞受体(TCR)谱的扭曲被新启动的(初级)T细胞群体中的多样性部分纠正。重要的是，在随后的抗原相遇中，这一原始种群的扩张更加强劲。这些发现表明，记忆T细胞群体在多重挑战中进化，有利于在最近的遭遇中产生的记忆T细胞，并表明这些初级群体在抗原特异性T细胞群体的永久化中起着至关重要的作用。

This project was intended to reveal the regulation of dynamic trafficking of subset of immune cells by chemokines to form immune-tissues in response to pathogen infection. As a result, the following points were found. 1. myeloid dendritic cells (mDCs) capture and process antigens, transport them from the tissue to the draining lymph nodes (LNs) and act as an antigen presenting cells, whereas plasmacytoid DCs (pDCs) directly migrate into inflamed LNs through HEV to help APC function of mDCs 2. nTreg home to the paracortex area of peripheral LNs through HEV in a CCR7 dependent manner and make cluster with subset of DCs 3. a primary response during re-challenge significantly contributes to memory T cell. Upon re-challenge, the skewed Vb usage and T-cell receptor (TCR) repertoire of pre-existing memory T cells is partly corrected by diversity in a newly primed (primary) T cell population. Importantly, this primary population expands more vigorously in a subsequent antigen encounter. These findings indicate that memory T cell populations evolve over multiple challenges, favoring memory T cells generated in more recent encounters, and suggest that these primary populations have essential roles in the perpetuation of antigen-specific T cell populations.