Figure 5

CD11b⁺ B1 cells express a unique phenotype. Adult peripheral blood mononuclear cells were immunofluorescently stained for surface CD3, CD19, CD20, CD27, CD43, CD11b, CD24 and CD38. Expression of CD38, CD24, CD20, CD19, CD27 and CD43 is shown for naive (CD3⁻CD20⁺CD27⁻CD43⁻) and memory (CD3⁻CD20⁺CD27⁺CD43⁻) B cells, and for CD11b⁻ (CD3⁻CD20⁺CD27⁺CD43⁺CD11b⁻) (B1-11b⁻) and CD11b⁺ (CD3⁻CD20⁺CD27⁺CD43⁺CD11b⁺) (B1-11b⁺) B1 cells, and for plasmablasts (CD3⁻CD19⁺CD20⁻), as indicated. Representative results from one of three comparable experiments are shown.