mature B cell marginal zone B cell of spleen MZ B lymphocyte marginal zone B cell marginal zone B lymphocyte marginal zone of spleen B cell A mature B cell that is located in the marginal zone of the spleen with the phenotype CD23-negative and CD21-positive and expressing a B cell receptor usually reactive to bacterial cell wall components or senescent self components such as oxidized-LDL. This cell type is also described as being CD19-positive, B220-positive, IgM-high, AA4-negative, CD35-high. B cell of marginal zone of spleen MZ B cell MZ B-cell marginal zone B-cell marginal zone B-lymphocyte MZ B-lymphocyte MZ B cells are reportedly CD1-positive (mice), CD20-positive, CD48-positive, CD84-positive, CD150-positive, CD229-positive, and CD352-positive. splenocyte