Open AccessHuman B cells accumulate immunoglobulin V gene somatic mutations in a cell contact‐dependent manner in cultures supported by activated T cells but not in cultures supported by CD40 ligand
Author(s) -
Huang Sc,
Annuska M. Glas,
Pinchuk Gv,
Van Montfort Eh,
Satish Rao,
Ronghua Jiang,
Milner Ec
Publication year - 1999
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1046/j.1365-2249.1999.00919.x
Subject(s) - cd40 , biology , immunoglobulin d , germinal center , somatic cell , microbiology and biotechnology , mutation , t cell , somatic hypermutation , b cell , antibody , in vitro , gene , immunology , immune system , genetics , cytotoxic t cell
The acquisition of somatic mutations in the rearranged immunoglobulin V regions in B cells occurs within the tightly regulated microenvironment of a germinal centre. The precise mechanism responsible for turning on the mutational process is unknown. To dissect the role of different components of the germinal centre in this mechanism, we have used in vitro cultures of normal human IgD + peripheral blood B lymphocytes co‐cultured with activated CD4 + T cells, or with resting CD4 + T cells, or with CD40 ligand and IL‐4. We observed that if the cultures included activated CD4 + T cells, then up to 100% of V H transcripts on day 14 were somatically mutated. Transcripts were found to carry from one to 36 substitutions (median five). In contrast, in the absence of activated T cells, transcripts contained only background levels of somatic mutation irrespective of the presence of resting T cells or CD40 ligand and IL‐4. Cell–cell contact was required for mutation because mutations were not detected when B cells were separated from activated T cells by a membrane.