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单细胞转录组分析流程十(免疫细胞细分,B/Myeloid 细胞篇)

在单细胞转录组研究中,除了 T 细胞和 NK 细胞,B 细胞和髓系细胞也是免疫系统中不可或缺的重要成员。它们在抗感染、防御肿瘤、炎症调控以及维持组织稳态中扮演核心角色。

一、B 细胞:体液免疫的核心力量

B 细胞主要负责体液免疫(humoral immunity),通过产生抗体来中和病原体或毒素。B 细胞可以进一步分化为不同亚型:

  • 初始 B 细胞(Naive B cells)
    刚从骨髓成熟进入外周血的 B 细胞,尚未接触抗原。它们具备识别广泛抗原的潜力,是免疫系统的“储备部队”。
  • 记忆 B 细胞(Memory B cells)
    接触过抗原后存活下来,快速响应同一病原体的再次感染。它们是疫苗能够长期保护的基础。
  • 浆细胞(Plasma cells)
    B 细胞激活后分化为抗体分泌工厂,产生大量针对特定抗原的免疫球蛋白(IgG、IgA、IgM 等)。

在单细胞数据中,B 细胞通常可通过标记基因识别,例如 CD19、CD20(MS4A1)、CD79A/B。浆细胞则表达 CD38、CD138(SDC1)、IGHG/IGHA 等高水平抗体相关基因。

二、B细胞的提取与注释

提取

B_sce <-  scRNA[,scRNA@meta.data$celltype %in% "B Cells"]

### 数据分层(因为后续要进行IntegrateLayers(Harmony))
B_sce[["RNA"]] <- split(B_sce[["RNA"]], f = B_sce$orig.ident)

### 标准化
B_sce <- NormalizeData(B_sce) 
B_sce <- FindVariableFeatures(B_sce, selection.method = "vst", nfeatures = 2000)
B_sce <- ScaleData(B_sce, 
                   features = VariableFeatures(B_sce), 
                   vars.to.regress = c("nCount_RNA", "percent.mt"))

### 聚类
B_sce <- RunPCA(B_sce, features = VariableFeatures(object = B_sce))

### 去批次
B_sce <- IntegrateLayers(
  object = B_sce, method = HarmonyIntegration,
  orig.reduction = "pca", new.reduction = "harmony",
  verbose = FALSE
)

### 确定维度
ElbowPlot(B_sce, ndims = 50)

### 聚类
B_sce <- FindNeighbors(B_sce, reduction = "harmony",dims = 1:10) 
B_sce <- FindClusters(object = B_sce , resolution =seq(0.1,2,0.1))

### 非线性降维
B_sce <- RunUMAP(B_sce,  dims = 1:10, reduction = "harmony")
B_sce <- RunTSNE(B_sce,  dims = 1:10, reduction = "harmony")
DimPlot(B_sce, reduction = "umap",group.by = "RNA_snn_res.0.3",label = T)
DimPlot(B_sce, reduction = "tsne",group.by = "RNA_snn_res.0.3",label = T)

### 换个配色
ngroups <- length(unique(B_sce$RNA_snn_res.0.3))
tableaucolors <- colorRampPalette(RColorBrewer::brewer.pal(13, "Paired"))(ngroups) 
DimPlot(B_sce, reduction = "tsne", label = T,group.by = "RNA_snn_res.0.3",cols = tableaucolors )
DimPlot(B_sce, reduction = "umap", label = T,group.by = "RNA_snn_res.0.3",cols = tableaucolors )

### 合并分层
B_sce <- JoinLayers(B_sce)

#保存
saveRDS(B_sce, file = "B_sce.rds")

B细胞分化途径

B cell(大类)
│
├── Naive B cell(初始B细胞)
│
├── Activated B cell(活化B细胞)
│    ├── Germinal center (GC) B cell 
│    │       ├── GC-LZ B cell(轻区)
│    │       └── GC-DZ B cell(暗区)
│    │
│    └── Pre-plasmablast / Activated B(部分文献会分为此类)
│
├── Memory B cell(记忆B)
│
└── Plasma lineage(分泌抗体)
     ├── Plasmablast(浆母细胞)
     └── Plasma cell(浆细胞)

marker基因

B 细胞亚群代表 Marker 基因功能/特征说明
泛 B 细胞(General B cells)MS4A1(CD20)、CD19、CD79A、CD79B、CD22、CD74、HLA-DRA/DRB1泛 B 细胞识别;抗原呈递;BCR 复合体组成部分
初始 B 细胞(Naive B cells)IGHM、IGHD、MS4A1、CD19、TCL1A、CD83未遇抗原;表达 IgM/IgD;典型 naive B 细胞标记
活化 B 细胞(Activated / GC B cells)BCL6、AICDA、MKI67、CXCR4、CXCR5、HLA-DRA活化与生发中心反应;高增殖;类切换重组
记忆 B 细胞(Memory B cells)CD27、BANK1、TNFRSF13B、IGHG1、IGHG3接触抗原后长期存活;快速二次应答能力
浆母细胞(Plasmablasts)MZB1、JCHAIN、CD38、PRDM1、XBP1、IGHG/IGHAB 向浆细胞的过渡状态;抗体分泌上升
浆细胞(Plasma cells)SDC1(CD138)、XBP1、MZB1、PRDM1、JCHAIN、IGKC/IGLC、IGHG/IGHA抗体高分泌“工厂”;强 UPR 激活;CD20 下调
调节性B细胞(Breg)IL10、CD1D、TGFB1免疫抑制(通过IL-10/TGF-β)

注释

markers <- c("MS4A1",   #General B
             "IGHM","IGHD",  #Naive B
             "BCL6", "AICDA", #Activated B
             "CD27","BANK1", "IGHG1","BLK","BANK1", # Memory B            
             "SDC1", "XBP1" # Plasma       
 )

VlnPlot(B_sce, features = markers, stack = T, flip = T,group.by = "RNA_snn_res.0.3") + 
        NoLegend()

B_sce$celltype <- recode (B_sce@meta.data$RNA_snn_res.0.3,
                            "0" = "Plasma cells",
                            "1" = "Naive B",
                            "2" = "Resting Memory B cells",
                            "3" = "Activated B",
                            "4" = "Memory B cells",
                            "5" = "Naive B",
                            "6" = "Plasma cells"
)

DimPlot(B_sce, reduction = "umap",group.by = "celltype",label = T)

三、髓系细胞:先天免疫的前线战士

髓系(Myeloid)细胞是一大类来源于骨髓的免疫细胞,主要承担**先天免疫(innate immunity)**功能,快速识别和应对入侵病原体。主要包括:

  • 单核细胞(Monocytes)
    循环血液中的游走细胞,可分化为巨噬细胞或树突状细胞。标记基因常见 CD14、CD16、LYZ
    功能:吞噬病原体、分泌炎症因子、参与组织修复。
  • 巨噬细胞(Macrophages)
    分布于组织中,负责清理死亡细胞、病原体,并调节炎症反应。不同组织巨噬细胞可有不同功能,例如肺巨噬细胞、肝库普弗细胞。标记基因包括 CD68、CD163、MRC1
  • 树突状细胞(Dendritic cells, DCs)
    核心抗原呈递细胞,将病原体信息呈递给 T 细胞,启动适应性免疫。标记基因包括 CD1C、CLEC9A、HLA-DR
  • 中性粒细胞(Neutrophils)
    快速响应感染的“第一道防线”,在炎症部位吞噬病原体并释放杀菌分子。标记基因如 S100A8/A9、MPO

功能亮点

  • 先天免疫监视与快速响应
  • 病原体吞噬与清除
  • 启动和调控适应性免疫(如 B/T 细胞)
  • 参与组织修复和炎症调控

四、髓系细胞的提取与注释

提取

M_sce <-  scRNA[,scRNA@meta.data$celltype %in% "Myeloid Cells"]

### 数据分层(因为后续要进行IntegrateLayers(Harmony))
M_sce[["RNA"]] <- split(M_sce[["RNA"]], f = M_sce$orig.ident)

### 标准化
M_sce <- NormalizeData(M_sce) 
M_sce <- FindVariableFeatures(M_sce, selection.method = "vst", nfeatures = 2000)
M_sce <- ScaleData(M_sce, 
                   features = VariableFeatures(M_sce), 
                   vars.to.regress = c("nCount_RNA", "percent.mt"))

### 聚类
M_sce <- RunPCA(M_sce, features = VariableFeatures(object = M_sce))

### 去批次
M_sce <- IntegrateLayers(
  object = M_sce, method = HarmonyIntegration,
  orig.reduction = "pca", new.reduction = "harmony",
  verbose = FALSE
)

### 确定维度
ElbowPlot(M_sce, ndims = 50)

### 聚类
M_sce <- FindNeighbors(M_sce, reduction = "harmony",dims = 1:20) 
M_sce <- FindClusters(object = M_sce , resolution =seq(0.1,2,0.1))

### 非线性降维
M_sce <- RunUMAP(M_sce,  dims = 1:15, reduction = "harmony")
M_sce <- RunTSNE(M_sce,  dims = 1:15, reduction = "harmony")
DimPlot(M_sce, reduction = "umap",group.by = "RNA_snn_res.0.7",label = T)
DimPlot(M_sce, reduction = "tsne",group.by = "RNA_snn_res.0.7",label = T)

### 换个配色
ngroups <- length(unique(M_sce$RNA_snn_res.0.7))
tableaucolors <- colorRampPalette(RColorBrewer::brewer.pal(13, "Paired"))(ngroups) 
DimPlot(M_sce, reduction = "tsne", label = T,group.by = "RNA_snn_res.0.7",cols = tableaucolors )
DimPlot(M_sce, reduction = "umap", label = T,group.by = "RNA_snn_res.0.7",cols = tableaucolors )

### 合并分层
M_sce <- JoinLayers(M_sce)

#保存
saveRDS(M_sce, file = "M_sce.rds")

分化途径

造血干细胞 (HSC)
 │
 └─> 多能造血祖细胞 (MPP)
       │
       └─> 髓系祖细胞 (CMP)
             │
             ├─> 粒-单核前体 (GMP)
             │     │
             │     ├─> 中性粒细胞前体 (Neutrophil progenitor)
             │     │       └─> 成熟中性粒细胞 (Neutrophil)
             │     │
             │     ├─> 嗜酸性粒细胞前体 (Eosinophil progenitor)
             │     │       └─> 成熟嗜酸性粒细胞 (Eosinophil)
             │     │
             │     ├─> 嗜碱性粒细胞前体 (Basophil progenitor)
             │     │       └─> 成熟嗜碱性粒细胞 (Basophil)
             │     │
             │     └─> 单核细胞前体 (Monocyte progenitor)
             │             └─> 单核细胞 (Monocyte)
             │                   ├─> 组织巨噬细胞 (Macrophage)
             │                   │       ├─> M1型 (促炎)
             │                   │       └─> M2型 (修复/抗炎)
             │                   └─> 树突状细胞 (DC)
             │                           ├─> 经典DC1 (cDC1)
             │                           ├─> 经典DC2 (cDC2)
             │                           └─> 浆细胞样DC (pDC)
             │
             └─> 粒-红祖细胞 (MEP)
                   ├─> 红细胞前体 (Erythroblast)
                   │       └─> 成熟红细胞 (Erythrocyte)
                   └─> 巨核细胞前体 (Megakaryoblast)
                           └─> 血小板 (Platelet)

marker基因

髓系大类亚型 / 细胞类型常用marker基因
粒细胞中性粒细胞CD66b, CXCR2, S100A8, S100A9, FCGR3B
粒细胞嗜酸性粒细胞CCR3, IL5RA, RNASE2, RNASE3, CLC
粒细胞嗜碱性粒细胞FCER1A, KIT, HDC, IL3RA
单核-巨噬系统经典单核细胞CD14, LYZ, S100A8, S100A9
单核-巨噬系统非经典单核细胞FCGR3A/CD16, CX3CR1
单核-巨噬系统中间单核细胞CD14, CD16, HLA-DR
单核-巨噬系统巨噬细胞 (M1型)CD80, CD86, IL1B, TNF
单核-巨噬系统巨噬细胞 (M2型)CD163, CD206/MRC1, IL10, ARG1
树突状细胞cDC1CLEC9A, XCR1, BATF3, IRF8
树突状细胞cDC2CD1C, FCER1A, IRF4
树突状细胞pDCIL3RA/CD123, CLEC4C/BDCA2, LILRA4
髓系抑制性细胞M-MDSCCD14+, HLA-DRlow/-
髓系抑制性细胞PMN-MDSCCD15+, CD66b+, CD33+, CD11b+

同样也可参考张泽民老师的文章

注释

markers <- c(
  "FCN1", "S100A8", "S100A9", "SMIM25", "LST1", "CDKN1C",
  "IL1B", "CCL4", "CCL3", "IER2", "FCGBP", "GPR34", "USP53", "C3", "TXNIP", "HLA-DPA1", "HLA-DPB1",
  "SELENOP", "PLTP", "F13A1", "IL2RA", "SPP1", "GPNMB", "CSTB", "FABP5", "MARCO", "TGFBI", "RNASE1", "C1QC", "LGMN", "CD1C", "PKIB", "FCER1A", 
  "CD1A", "CD207", "S100B", "BATF3", "CLEC9A", "CADM1",  "IL3RA", "LILRA4",
  "LAMP3", "FSCN1","CCR7", "STMN1", "MKI67", "TOP2A",
  " TPSAB1","TPSB2"
)


  DotPlot(M_sce, features = markers, group.by = "RNA_snn_res.0.7") +
    RotatedAxis()

M_sce$celltype <- recode (M_sce@meta.data$RNA_snn_res.0.7,
                            "0" = "IL1B⁺ macro",
                            "1" = "CD1C⁺CD1A⁺ cDC2",
                            "2" = "FCN1⁺CD14⁺ mono",
                            "3" = "SPP1⁺MARCO⁺ macro",
                            "4" = "SELENOP⁺ macro",
                            "5" = "SPP1⁺TGFB1⁺ macro",
                            "6" = "Mast Cells",
                            "7" = "Proliferating cell",
                            "8" = "FCGBP⁺ macro",
                            "9" = "pDC",
                            "10" = "Activated DC",
)

DimPlot(M_sce, reduction = "umap",group.by = "celltype",label = T)


原文地址:https://blog.csdn.net/2302_80302343/article/details/155499502

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