title: Memory B lymphocytes determine repertoire oligoclonality early after haematopoietic stem cell transplantation.
abstract: The objective of this study was to investigate if oligoclonality of the Ig repertoire post-haematopoietic stem cell transplantation (HSCT) is restricted to memory B lymphocytes or if it is a general property among B lymphocytes. As a measure of B lymphocyte repertoire diversity, we have analysed size distribution of polymerase chain reaction (PCR) amplified Ig H complementarity determining region 3 (CDR3) in naive and memory B lymphocytes isolated from patients before HSCT and at 3, 6 and 12 months after HSCT as well as from healthy controls. We demonstrate a limited variation of the IgH CDR3 repertoire in the memory B lymphocyte population compared to the naive B cell population. This difference was significant at 3 and 6 months post-HSCT. Compared to healthy controls there is a significant restriction of the memory B lymphocyte repertoire at 3 months after HSCT, but not of the naive B lymphocyte repertoire. Twelve months after HSCT, the IgH CDR3 repertoire in both memory and naive B lymphocytes are as diverse as in healthy controls. Thus, our findings suggest a role for memory B cells in the restriction of the oligoclonal B cell repertoire observed early after HSCT, which may be of importance when considering reimmunization of transplanted patients.
authors.affiliation: Department of Microbiology, Karolinska Institutet, Huddinge University Hospital, Sweden. brigitta.omazic@cfss.ki.se
authors.forename: B
authors.initials: B
authors.lastname: Omazic
authors.forename: I
authors.initials: I
authors.lastname: Lundkvist
authors.forename: J
authors.initials: J
authors.lastname: Mattsson
authors.forename: J
authors.initials: J
authors.lastname: Permert
authors.forename: I
authors.initials: I
authors.lastname: Nasman-Bjork
mesh_terms: D000328:Adult; D000916:Antibody Diversity; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D016022:Case-Control Studies; D002999:Clone Cells; D022801:Complementarity Determining Regions / Q000235:genetics*; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D005803:Genes, Immunoglobulin; D006086:Graft vs Host Disease / Q000517:prevention & control; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D011184:Postoperative Period; D018709:Statistics, Nonparametric; D019172:Transplantation Conditioning; D014182:Transplantation, Autologous; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000276:immunology
chemical_list: D022801:Complementarity Determining Regions; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7