title: Limiting dilution assay for human B cells based on their activation by mutant EL4 thymoma cells: total and antimalaria responder B cell frequencies.
abstract: The analysis of human B cell responses at the clonal level (limiting dilution assay) is still technically difficult. In the present study we report on a culture system that leads to activation, proliferation and differentiation into antibody-secreting cells (ASC) of about 90% of B cells from peripheral blood or spleen. In this system, B cells are cultured in the presence of a mutant subclone of the mouse thymoma EL4 for B cell activation and human T cell plus macrophage supernatant as source of proliferation and differentiation factors. ASC precursors generating clonal responses of IgM only, IgM plus IgG, or IgG only occurred at a ratio of about 6:3:1. The mean clone size was 380 cytoplasmic Ig+ cells; the mean amount of Ig secreted per clone was 20 ng. Furthermore, it has been found using this system that a considerable proportion of peripheral blood B cells from individuals with a history of malaria infection could generate clones of anti-malaria (Plasmodium falciparum) ASC (range of 0.1 to 1%, n = 6). In a control group of blood donors the corresponding frequencies were 10 times lower (range of 0.01 to 0.1%, n = 9). These results show that the EL4 culture system can be applied to the investigation of the human B cell specificity repertoire and of priming effects such as result from infectious disease.
authors.forename: L
authors.initials: L
authors.lastname: Wen
authors.forename: M
authors.initials: M
authors.lastname: Hanvanich
authors.forename: C
authors.initials: C
authors.lastname: Werner-Favre
authors.forename: N
authors.initials: N
authors.lastname: Brouwers
authors.forename: L H
authors.initials: LH
authors.lastname: Perrin
authors.forename: R H
authors.initials: RH
authors.lastname: Zubler
mesh_terms: D000328:Adult; D000921:Antibody-Producing Cells / Q000166:cytology / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002450:Cell Communication; D002452:Cell Count; D002460:Cell Line; D005260:Female; D006133:Growth Substances / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000276:immunology; D008264:Macrophages / Q000378:metabolism; D008288:Malaria / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010963:Plasmodium falciparum / Q000276:immunology; D013154:Spleen / Q000166:cytology; D013945:Thymoma / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan; D006133:Growth Substances; D008222:Lymphokines; D015847:Interleukin-4