查看“MHC-II/抗原肽”的源代码

<div style="padding: 0 4%; line-height: 1.8; color: #1e293b; font-family: 'Helvetica Neue', Helvetica, 'PingFang SC', Arial, sans-serif; background-color: #ffffff; max-width: 1200px; margin: auto;">

    <div style="margin-bottom: 30px; border-bottom: 1.2px solid #e2e8f0; padding-bottom: 25px;">
        <p style="font-size: 1.1em; margin: 10px 0; color: #334155; text-align: justify;">
            <strong>[[MHC-II/抗原肽]] 复合物 (pMHC-II Complex)</strong> 是细胞免疫识别中的关键分子信号，由 <strong>[[MHC-II]]</strong> 类分子的 $\alpha$ 链与 $\beta$ 链二聚体结合一个 <strong>外源性抗原肽</strong>（通常为 13-18 个氨基酸）组成。该复合物主要由 <strong>[[专业 APC]]</strong>（如树突状细胞、巨噬细胞和 B 细胞）通过内吞作用摄取外部病原体，并在溶酶体中加工后生成。它是激活 <strong>[[辅助性 T 细胞]] (Th)</strong> 的物理基础，决定了机体产生抗体（体液免疫）或炎症反应（细胞免疫）的方向。
        </p>
    </div>

    <div class="medical-infobox mw-collapsible mw-collapsed" style="width: 380px; float: right; margin: 0 0 25px 25px; border: 1.2px solid #bae6fd; border-radius: 12px; background-color: #ffffff; box-shadow: 0 8px 20px rgba(0,0,0,0.05); overflow: hidden;">
        
        <div style="padding: 15px; color: #1e40af; background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%); text-align: center; cursor: pointer;">
            <div style="font-size: 1.25em; font-weight: bold; letter-spacing: 1.2px;">MHC-II/抗原肽</div>
            <div style="font-size: 0.7em; opacity: 0.85; margin-top: 4px; white-space: nowrap;">pMHC-II · 核心参数</div>
        </div>
        
        <div class="mw-collapsible-content">
            <div style="padding: 20px; text-align: center; background-color: #f8fafc;">
                
                <div style="font-size: 0.8em; color: #64748b; margin-top: 10px; font-weight: 600;">核心特性：外源性免疫监控</div>
            </div>

            <table style="width: 100%; border-spacing: 0; border-collapse: collapse; font-size: 0.82em;">
                <tr style="background-color: #f1f5f9; color: #1e40af; font-weight: bold; text-align: center;">
                    <td colspan="2" style="padding: 6px; border-bottom: 1px solid #e2e8f0;">分子构成</td>
                </tr>
                <tr>
                    <th style="text-align: left; padding: 6px 10px; background-color: #f8fafc; border-bottom: 1px solid #f1f5f9; width: 40%;">蛋白组成</th>
                    <td style="padding: 6px 10px; border-bottom: 1px solid #f1f5f9; color: #0f172a;">$\alpha$ 链 + $\beta$ 链 (非共价)</td>
                </tr>
                <tr>
                    <th style="text-align: left; padding: 6px 10px; background-color: #f8fafc; border-bottom: 1px solid #f1f5f9;">抗原来源</th>
                    <td style="padding: 6px 10px; border-bottom: 1px solid #f1f5f9; color: #1e40af;">外源性 (细菌、病毒、毒素)</td>
                </tr>
                <tr>
                    <th style="text-align: left; padding: 6px 10px; background-color: #f8fafc; border-bottom: 1px solid #f1f5f9;">肽段长度</th>
                    <td style="padding: 6px 10px; border-bottom: 1px solid #f1f5f9; color: #0f172a;">13 - 18 氨基酸 (两端开放)</td>
                </tr>
                <tr style="background-color: #f1f5f9; color: #1e40af; font-weight: bold; text-align: center;">
                    <td colspan="2" style="padding: 6px; border-bottom: 1px solid #e2e8f0;">生物学功能</td>
                </tr>
                <tr>
                    <th style="text-align: left; padding: 6px 10px; background-color: #f8fafc; border-bottom: 1px solid #f1f5f9;">主要提呈细胞</th>
                    <td style="padding: 6px 10px; border-bottom: 1px solid #f1f5f9; color: #0f172a;">[[树突状细胞]], [[B 细胞]]</td>
                </tr>
                <tr>
                    <th style="text-align: left; padding: 6px 10px; background-color: #f8fafc; border-bottom: 1px solid #f1f5f9;">识别 T 细胞</th>
                    <td style="padding: 6px 10px; border-bottom: 1px solid #f1f5f9; color: #1e40af;"><strong>[[CD4+ T (Th)]]</strong></td>
                </tr>
                <tr style="background-color: #f1f5f9; color: #1e40af; font-weight: bold; text-align: center;">
                    <td colspan="2" style="padding: 6px; border-bottom: 1px solid #e2e8f0;">加工转运</td>
                </tr>
                <tr>
                    <th style="text-align: left; padding: 6px 10px; background-color: #f8fafc; border-bottom: 1px solid #f1f5f9;">关键伴侣</th>
                    <td style="padding: 6px 10px; border-bottom: 1px solid #f1f5f9; color: #0f172a;">[[Ii 链 (Invariant chain)]]</td>
                </tr>
                <tr>
                    <th style="text-align: left; padding: 6px 10px; background-color: #f8fafc;">编辑分子</th>
                    <td style="padding: 6px 10px; color: #0f172a;">[[HLA-DM]]</td>
                </tr>
            </table>
        </div>
    </div>

    <h2 style="background: #f1f5f9; color: #0f172a; padding: 10px 18px; border-radius: 0 6px 6px 0; font-size: 1.25em; margin-top: 40px; border-left: 6px solid #0f172a; font-weight: bold;">加工与提呈路径：外源性抗原的历程</h2>

    

    <p style="margin: 15px 0; text-align: justify;">
        MHC-II 分子提呈抗原的过程是一个精密的细胞内协作过程，其逻辑在于避免提呈细胞内的自身蛋白：
    </p>
    <ul style="padding-left: 25px; color: #334155;">
        <li style="margin-bottom: 12px;"><strong>内吞与降解：</strong> APC 通过胞吞作用将外源性蛋白质摄入，在 <strong>[[内吞体]]</strong> 和溶酶体中被蛋白酶降解为短肽。</li>
        <li style="margin-bottom: 12px;"><strong>Ii 链的保护：</strong> 在内质网中，新合成的 MHC-II 分子与 <strong>[[Ii 链]]</strong> 结合。Ii 链占据了肽结合槽，防止内源性肽段错误进入，并引导复合物转运至内吞体。</li>
        <li style="margin-bottom: 12px;"><strong>CLIP 的形成与替换：</strong> Ii 链在内吞体中被降解，仅余一小段名为 <strong>[[CLIP]]</strong> 的多肽留在槽内。随后在 <strong>[[HLA-DM]]</strong> 的催化下，高亲和力的外源抗原肽将 CLIP 替换。</li>
        <li style="margin-bottom: 12px;"><strong>表面展示：</strong> 稳定的 pMHC-II 复合物转运至细胞表面，等待 <strong>[[辅助性 T 细胞 (Th)]]</strong> 的扫描。</li>
    </ul>

    <h2 style="background: #f1f5f9; color: #0f172a; padding: 10px 18px; border-radius: 0 6px 6px 0; font-size: 1.25em; margin-top: 40px; border-left: 6px solid #0f172a; font-weight: bold;">与 MHC-I 复合物的对比分析</h2>

    <div style="overflow-x: auto; margin: 30px auto; max-width: 95%;">
        <table style="width: 100%; border-collapse: collapse; border: 1.2px solid #cbd5e1; font-size: 0.92em; text-align: left;">
            <tr style="background-color: #f8fafc; border-bottom: 2px solid #0f172a;">
                <th style="padding: 12px; border: 1px solid #cbd5e1; color: #0f172a; width: 25%;">特征</th>
                <th style="padding: 12px; border: 1px solid #cbd5e1; color: #1e40af;">[[MHC-II/抗原肽]]</th>
                <th style="padding: 12px; border: 1px solid #cbd5e1; color: #475569;">[[MHC-I/抗原肽]]</th>
            </tr>
            <tr>
                <td style="padding: 10px; border: 1px solid #cbd5e1; font-weight: 600;">识别受体</td>
                <td style="padding: 10px; border: 1px solid #cbd5e1;">TCR + <strong>[[CD4]]</strong></td>
                <td style="padding: 10px; border: 1px solid #cbd5e1;">TCR + <strong>[[CD8]]</strong></td>
            </tr>
            <tr>
                <td style="padding: 10px; border: 1px solid #cbd5e1; font-weight: 600;">肽结合槽</td>
                <td style="padding: 10px; border: 1px solid #cbd5e1;">两端开放 (肽段可伸出)</td>
                <td style="padding: 10px; border: 1px solid #cbd5e1;">两端封闭 (袋状结构)</td>
            </tr>
            <tr>
                <td style="padding: 10px; border: 1px solid #cbd5e1; font-weight: 600;">分布范围</td>
                <td style="padding: 10px; border: 1px solid #cbd5e1;">仅限 <strong>[[专业 APC]]</strong></td>
                <td style="padding: 10px; border: 1px solid #cbd5e1;">几乎所有有核细胞</td>
            </tr>
        </table>
    </div>

    <h2 style="background: #f1f5f9; color: #0f172a; padding: 10px 18px; border-radius: 0 6px 6px 0; font-size: 1.25em; margin-top: 40px; border-left: 6px solid #0f172a; font-weight: bold;">权威学术文献与点评</h2>

    <div style="font-size: 0.92em; line-height: 1.6; color: #1e293b; margin-top: 15px; border-top: 2.2px solid #0f172a; padding: 15px 25px; background-color: #f8fafc; border-radius: 0 0 10px 10px;">
        <span style="color: #0f172a; font-weight: bold; font-size: 1.05em; display: inline-block; margin-bottom: 15px;">学术参考文献 [Academic Peer Review]</span>
        
        <p style="margin: 12px 0; border-bottom: 1px solid #e2e8f0; padding-bottom: 10px;">
            [1] <strong>Neefjes, J., et al. (2011).</strong> <em>Towards a systems understanding of MHC class I and MHC class II antigen presentation.</em> <strong>Nature Reviews Immunology</strong>, 11(12), 823-836.<br>
            <span style="color: #475569;">[点评]：目前对 MHC 两类提呈路径最具权威性的综合评述，详尽区分了内吞路径与内质网路径的差异。</span>
        </p>
        
        <p style="margin: 12px 0; border-bottom: 1px solid #e2e8f0; padding-bottom: 10px;">
            [2] <strong>Roche, P. A., & Furuta, K. (2015).</strong> <em>The ins and outs of MHC class II-mediated antigen processing and presentation.</em> <strong>Nature Reviews Immunology</strong>, 15(4), 203-216.<br>
            <span style="color: #475569;">[点评]：专注于 MHC-II 的分子生物学过程，特别是 Ii 链、CLIP 和 HLA-DM 在肽交换中的角色。</span>
        </p>
    </div>

    <h2 style="background: #f1f5f9; color: #0f172a; padding: 10px 18px; border-radius: 0 6px 6px 0; font-size: 1.25em; margin-top: 40px; border-left: 6px solid #0f172a; font-weight: bold;">关键相关概念</h2>
    <div style="background-color: #f8fafc; border: 1px solid #e2e8f0; border-radius: 8px; padding: 15px; margin: 20px 0;">
        <ul style="margin: 0; padding-left: 20px; color: #334155;">
            <li style="margin-bottom: 8px;"><strong>[[HLA-DM]]：</strong> 催化 CLIP 释放并辅助抗原肽装载的关键编辑分子。</li>
            <li style="margin-bottom: 8px;"><strong>[[内吞路径]]：</strong> pMHC-II 形成的主要场所。</li>
            <li style="margin-bottom: 8px;"><strong>[[Th1/Th2 平衡]]：</strong> T 细胞识别 pMHC-II 后，由细胞因子环境决定的分化结果。</li>
        </ul>
    </div>

    <div style="margin: 40px 0; border: 1px solid #e2e8f0; border-radius: 8px; overflow: hidden; font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 0.9em;">
        <div style="background-color: #eff6ff; color: #1e40af; padding: 8px 15px; font-weight: bold; text-align: center; border-bottom: 1px solid #dbeafe;">
            MHC-II/抗原肽 · 知识图谱
        </div>
        <table style="width: 100%; border-collapse: collapse; background-color: #ffffff;">
            <tr style="border-bottom: 1px solid #f1f5f9;">
                <td style="width: 110px; background-color: #f8fafc; color: #334155; font-weight: 600; padding: 10px 12px; text-align: right; vertical-align: middle; white-space: nowrap;">关键分子轴</td>
                <td style="padding: 10px 15px; color: #334155;">[[Ii 链]]•[[CLIP]]•[[HLA-DM]]•[[TCR-CD4]]</td>
            </tr>
            <tr style="border-bottom: 1px solid #f1f5f9;">
                <td style="width: 110px; background-color: #f8fafc; color: #334155; font-weight: 600; padding: 10px 12px; text-align: right; vertical-align: middle; white-space: nowrap;">提呈效应</td>
                <td style="padding: 10px 15px; color: #334155;">[[激活辅助性T细胞]]•[[启动抗体产生]]•[[炎症调节]]</td>
            </tr>
            <tr style="border-bottom: 1px solid #f1f5f9;">
                <td style="width: 110px; background-color: #f8fafc; color: #334155; font-weight: 600; padding: 10px 12px; text-align: right; vertical-align: middle; white-space: nowrap;">临床关联</td>
                <td style="padding: 10px 15px; color: #334155;">[[自身抗原误提呈]]•[[感染防御]]•[[器官移植排斥]]</td>
            </tr>
        </table>
    </div>

</div>