Table 1.
Discrete double-negative (DN) B cell subsets.
| Nomenclature | Phenotype | Prominence in (condition) | Properties | References |
|---|---|---|---|---|
| DN1 | CD19+IgD−CD27−CD21+ CD11c− T-bet− CXCR5+ |
Elderly healthy individuals (aging) | Memory precursors | [16,17] |
| DN2 | CD19+IgD−CD27−CD21− CD11c+ T-bet+CXCR5− |
SLE (autoimmunity) | Extrafollicular ASC precursors | [17] |
| DN3 | CD19+IgD−CD27−CD21− CD11c− [T-betlow] |
COVID-19 | ?? | [7,8] |
| atMEM/tbMEM | CD19+IgD−CD27− CD21−FcRL4+ |
Chronic infections | Exhausted, mucosal resident B cells | [35,36] |
DN1, DN2 and DN3: first, second and third subset of DN B cells, respectively; atMEM/tbMEM: atypical/tissue-based memory B cells; SLE: Systemic Lupus Erythematosus; ASC: antibody-secreting cell.