Granulocytes

Granulocytes are a category of white blood cells involved in the defence against bacteria and parasites. They characterized by the presence of granules in their cytoplasm that contain, e.g., defensins, lysozymes and histamines. Granulocytes are produced via granulopoiesis in the bone marrow, and the most abundant of the granulocytes is the neutrophil granulocyte, while the other types (eosinophils, basophils, and mast cells) have lower numbers.

In the Blood Atlas we have 1160 cell lineage enriched genes and 273 of these genes has the highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed. In addition, 795 genes are cell lineage group enriched and an additional 35 genes are enhanced in this cell lineage. Altogether, 1990 genes are elevated and among these 448 also show highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed.

Figure 1. The distribution of all genes across the five specificity categories based on transcript abundance in granulocyte cell lineage as well as in the other 5 cell lineages.

Table 1. Number of genes in the subdivided categories of elevated expression in granulocyte cell lineage.

Table 2. The genes with the highest level of enriched expression in granulocyte cell lineage. "pTPM" shows the transcript level as protein-coding transcripts per million. Specificity-score corresponds to the score calculated as the fold change of granulocyte cell lineage expression to the second highest cell lineage.

Basophils

Basophils are responsible for inflammatory reactions during immune response. They have granules containing histamine, heparin, chondroitin sulfate, peroxidase and platelet-activating factor, and upon an infection they will travel from the bone marrow to the site of infection and release the granule content which will contribute to inflammation.

In the Blood Atlas we have 225 basophil enriched genes and 41 of these genes has the highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed. In addition, 301 genes are cell type group enriched and an additional 400 genes are enhanced in this cell type. Altogether, 926 genes are elevated and among these 187 also show highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed.

Isolation of the basophils was done from whole blood. Erythrocytes were eliminated by HetaSep sedimentation method. Remaining erythrocytes, debris and cell aggregates were eliminated by gating on CD45+ cells and based on scatter profiles. The basophils were sorted as CD123+/CD193+/CD38+/CD3neg/CD11cneg/ CD15neg/CD16neg/CD20neg/CD56neg/HLA-Drneg/SSClow cells, and 2,000 – 5,800 cells were sorted per sample for transcriptomic analysis by mRNA-sequencing. The transcriptome analysis shows that 50% (n=9881) of all human proteins (n=19,670) are expressed in the basophils and 301 of these genes show an elevated expression in basophils compared to the other 17 cell types (see figure below).

Figure 2. The distribution of all genes across the five specificity categories based on transcript abundance in basophil cell type as well as in the other 17 cell types.

Table 3. Number of genes in the subdivided categories of elevated expression in basophils.

Table 4. The genes with the highest level of enriched expression in basophils. "pTPM" shows the transcript level as protein-coding transcripts per million. Specificity-score corresponds to the score calculated as the fold change of basophil cell type expression to the second highest cell type.

Eosinophils

Eosinophils mainly function in defence against multicellular parasites, but they also function as antigen-presenting cells and can participate in phagocytosis. They fight parasites by releasing the toxic chemical mediators, including eosinophil peroxidase, lipase, major basic protein, RNase and DNase, contained in their granules.

In the Blood Atlas we have 106 eosinophil enriched genes and 26 of these genes has the highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed. In addition, 321 genes are cell type group enriched and an additional 252 genes are enhanced in this cell type. Altogether, 679 genes are elevated and among these 161 also show highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed.

The eosinophils were isolated from whole blood. Erythrocytes were eliminated by the HetaSep sedimentation method. Remaining erythrocytes, debris and cell aggregates were eliminated by gating on CD45+ events and based on scatter profile. The eosinophils were sorted as CD193+/CD15low/CD16low/HLA-Drlow/SSChigh cells and 8,000 – 30,000 cells were sorted per sample for transcriptomic analysis by mRNA-sequencing.The transcriptome analysis shows that 49% (n=9608) of all human proteins (n=19,670) are expressed in the eosinophils and 321 of these genes show an elevated expression in eosinophils compared to the other 17 cell types (see figure below).

Figure 3. The distribution of all genes across the five specificity categories based on transcript abundance in eosinophil cell type as well as in the other 17 cell types.

Table 5. Number of genes in the subdivided categories of elevated expression in esinophils.

Table 6. The genes with the highest level of enriched expression in esinophils. "pTPM" shows the transcript level as protein-coding transcripts per million. Specificity-score corresponds to the score calculated as the fold change of eosinophil expression to the second highest cell type.

Neutrophils

Neutrophils are considered the first line of defence in the innate immune system, and are involved in the healing of damaged tissues and the defence against infections. They are the most abundant leukocytes in the circulation and capture and destroy invading micro-organisms by phagocytosis, release of bactericidal and protein-destroying compounds from the granules, and by the generation of neutrophil extracellular traps (NETs), but they also participate as mediators of inflammation.

In the Blood Atlas we have 355 neutrophil enriched genes and 87 of these genes has the highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed. In addition, 391 genes are cell type group enriched and an additional 715 genes are enhanced in this cell type. Altogether, 1461 genes are elevated and among these 347 also show highest expression in blood or lymphoid tissues when comparing all tissues and organs analysed.

The neutrophils were isolated from whole blood. Erythrocytes were eliminated by the HetaSep sedimentation method. Remaining erythrocytes, debris and cell aggregates were eliminated by gating on CD45+ events and scatter profiles. The neutrophils were sorted as CD15+/CD16+/SSChigh cells, and 50,000 – 190,000 cells were sorted per sample for transcriptomic analysis by mRNA-sequencing. The transcriptome analysis shows that 52% (n=10179) of all human proteins (n=19,670) are expressed in the neutrophils and 391 of these genes show an elevated expression in neutrophils compared to the other 17 cell types (see figure below).

Figure 4. The distribution of all genes across the five specificity categories based on transcript abundance in neutrophil cell type as well as in the other 17 cell types.

Table 7. Number of genes in the subdivided categories of elevated expression in neutrophils.

Table 8. The genes with the highest level of enriched expression in neutrophils. "pTPM" shows the transcript level as protein-coding transcripts per million. Specificity-score corresponds to the score calculated as the fold change of neutrophil cell expression to the second highest cell type.