MOLECULAR CHARACTERIZATION OF SINGLE MEMORY B-CELLS

MCHEYZERWILLIAMS, MG; Nossal, GJV; LALOR, PA

Author(s): MCHEYZERWILLIAMS, MG; Nossal, GJV; LALOR, PA;
Details: Publication Year 1991-04-11,Volume 350,Issue #6318,Page 502-505
Journal Title: NATURE
Publication Type: Journal Article
Abstract: PRIMARY antigenic exposure results in an initial antibody response and the T cell-dependent induction of B-cell memory 1,2. Memory B-cell differentiation is characterized by somatic hypermutation in antibody variable region genes (V) and selection of B cells expressing high-affinity variants of this antigen receptor 3-5. Despite our current understanding of B-cell memory 6-8, the origin of memory B cells and the regulation of their differentiation remain elusive. This is largely due to the difficulties in observing and purifying this minor component of the immunized spleen. Further, molecular characterization of memory B cells requires hybridoma formation which restricts analyses to only those clones capable of fusion and does not allow isolation of cells in a normal physiological state. We have therefore developed a unique system which allows isolation and unambiguous enumeration of IgG1+ memory B cells, based on six-parameter flow cytometry, secretion of antibody in clonal cultures and analysis of clonally expressed V genes using the polymerase chain reaction 9. Here we report that single IgG1+ antigen-binding B cells from an early secondary immune response proliferate in lipopolysaccharide-driven microcultures and produce antigen-specific IgG1 antibodies. Individual B-cell clones in these cultures express somatically mutated heavy chain V genes, confirming their designation as memory B cells. Although isolated memory B cells undergo extensive proliferation in vitro, V gene sequence analysis of their individual progeny shows that further hypermutation does not occur.
Publisher: MACMILLAN MAGAZINES LTD
Keywords: SOMATIC MUTATION; IMMUNE-RESPONSE; ANTIBODY REPERTOIRE; MOUSE; HYPERMUTATION; GENERATION; ANTIGEN; MICE; DNA; NP
Publisher's Version: https://doi.org/10.1038/350502a0
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 1991-04-11 12:00:00