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/IGHA | B 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 | cDC1 | CLEC9A, XCR1, BATF3, IRF8 |
| 树突状细胞 | cDC2 | CD1C, FCER1A, IRF4 |
| 树突状细胞 | pDC | IL3RA/CD123, CLEC4C/BDCA2, LILRA4 |
| 髓系抑制性细胞 | M-MDSC | CD14+, HLA-DRlow/- |
| 髓系抑制性细胞 | PMN-MDSC | CD15+, 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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