CD40 ligand and appropriate cytokines induce switching to IgG, IgA, and IgE and coordinated germinal center and plasmacytoid phenotypic differentiation in a human monoclonal IgM+IgD+ B cell line.
B lymphocytes are induced to undergo Ig class switching and a complex phenotypic differentiation by the milieu of the germinal center. Partly as a result of the lack of a suitable in vitro B cell model, the relationship between these processes in the humans has never been formally established in vitro. We have identified a human monoclonal B cell line, CL-01, that expresses surface IgM and IgD and, upon induction with CD40 ligand, IL-4, and IL-10, switches to all seven downstream isotypes, showing typical DNA switch recombination preceded by germline transcription of targeted CH regions. In CL-01 cells, switch-inducing stimuli trigger concomitant changes in expression of surface IgD, CD23, CD38, and CD77 that parallel those reported in ex vivo isolated tonsillar centroblasts, centrocytes, and memory B cells. Eventually, in the presence of IL-6, CL-01 cells express CD56 and accumulate cytoplasmic IgG and IgA, both traits of plasmacytoid differentiation. Analysis of transcription and recombination of the Ig H locus in sorted CL-01 cells suggest that Ig class switching begins in centroblasts, it extends to all isotypes in centrocytes, and it is extinct in memory B cells. Thus, we have induced coordinated Ig class switching, progression through germinal center phenotypic stages, and differentiation to memory B cells and plasma cells at the level of a single B clonotype. Our data suggest that these processes are likely regulated by a common maturation program, the activation of which may require CD40 ligand, IL-4, IL-10, and IL-6 only.
Cerutti
A
A
Department of Pathology, Cornell University Graduate School of Medical Sciences, New York 10021, USA.
Zan
H
H
Schaffer
A
A
Bergsagel
L
L
Harindranath
N
N
Max
E E
EE
Casali
P
P
D000911:Antibodies, Monoclonal / Q000096:biosynthesis*; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D019013:CD40 Antigens / Q000502:physiology*; D023201:CD40 Ligand; D019002:CD56 Antigen / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D002999:Clone Cells; D016207:Cytokines / Q000502:physiology*; D015322:Gene Rearrangement, B-Lymphocyte / Q000235:genetics; D018858:Germinal Center / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis / Q000235:genetics; D017578:Immunoglobulin Class Switching / Q000235:genetics; D007072:Immunoglobulin D / Q000096:biosynthesis; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000235:genetics; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D016130:Immunophenotyping; D015847:Interleukin-4 / Q000502:physiology; D015850:Interleukin-6 / Q000502:physiology; D008024:Ligands; D008562:Membrane Glycoproteins / Q000276:immunology / Q000502:physiology*; D008969:Molecular Sequence Data; D010950:Plasma Cells / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure; D011947:Receptors, Antigen, B-Cell / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic / Q000276:immunology
D000911:Antibodies, Monoclonal; D019013:CD40 Antigens; D019002:CD56 Antigen; D016207:Cytokines; D007070:Immunoglobulin A; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D015850:Interleukin-6; D008024:Ligands; D008562:Membrane Glycoproteins; D011947:Receptors, Antigen, B-Cell; D023201:CD40 Ligand; D015847:Interleukin-4; D007073:Immunoglobulin E