lacks_plasma_membrane_part has plasma membrane part output of mature B cell memory B cell Memory B-cells are also reportedly CD5-negative, CD10-negative, CD21-positive, CD22-positive, CD23-negative, CD24-positive, CD25-positive, CD27-positive, CD34-negative, CD38-negative, CD40-positive, CD43-negative, CD44-positive, CD45-positive, CD53-positive, CD80-negative, CD81-negative, CD86-positive, and CD196/CCR6-positive. memory B lymphocyte memory B-lymphocyte A memory B cell is a mature B cell that is long-lived, readily activated upon re-encounter of its antigenic determinant, and has been selected for expression of higher affinity immunoglobulin. This cell type has the phenotype CD19-positive, CD20-positive, MHC Class II-positive, and CD138-negative. ZFA:0009333 memory B-cell Memory B cells are a subtype of B cells that play a significant role in the adaptive immune response. They originate as part of B lymphocytes lineage and differentiate into memory B cells after activation by an antigen. The primary function of memory B cells is to respond rapidly to preexposure of the same antigen which originally activated it. Upon re-encountering the antigen, memory B cells can quickly differentiate into plasmablasts to generate antibodies or seed germinal centers to generate a robust immune response. Memory B cells can derive from mature B cells that undergo the germinal center reaction or those that differentiate in extrafollicular clusters. It is generally thought that memory B cells activated via the extrafollicular pathway are shorter-lived and produce lower-affinity antibodies, while those activated in germinal centers are longer-lived and produce high-affinity antibodies, having undergone somatic hypermutation. Memory B cells have a prolonged lifespan, lasting for years or even decades, enabling them to provide sustained protection against repeated or persistent infections. These cells are therefore a fundamental component of humoral immunological memory. As such, these cells are also important factors in the response to immunization/ (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) https://cellxgene.cziscience.com/cellguide/CL_0000787 B cell affinity maturation MHC class II protein complex Homo sapiens membrane-spanning 4-domains subfamily A member 1 syndecan-1