Open AccessDelineation of producing ability of IgG and IgA subclasses by naive B cells in newborn infants and adult individuals
Author(s) -
YACHIE A.,
KONNO A.,
OHTA K.,
WADA T.,
SEKI H.,
TANIGUCHI N.,
MIYAWAKI T.
Publication year - 1995
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 - 10.1111/j.1365-2249.1995.tb06657.x
Subject(s) - immunology , biology , naive b cell , b cell , antibody , subclass , memory b cell , cd40 , immune system , t cell , cytotoxic t cell , in vitro , antigen presenting cell , genetics
SUMMARY Neonatal B cells with the naive (sIgD + ) phenotype are able to generate IgG‐ and IgA‐producing cells as well as IgM production in the presence of memory CD4 + T cells expressing L‐selectin (CD62L) in pokeweed mitogen‐stimulated cultures. We used this system to examine comparatively the ability of naive B cells to produce IgG and IgA subclasses in newborn infants and adult individuals. Naive B cells were enriched from both donors on the basis of sIgD positivity, and memory (CD45RO + ) CD4 + T cells with CD62L expression were isolated from adults. We here demonstrate some differences in profiles of IgG and IgA subclass production between neonatal and adult naive B cells. In neonatal B cells, IgG1 and IgG3 were predominantly produced, but IgG2 and IgG4 production was virtually absent. Similar to neonatal B cells, adult naive B cells produced mainly IgGq and IgG3, although memory (sIgD’) B cells from adults secreted all of the IgG subclasses. It should be noted that low but detectable levels of IgG2 and IgG4 were found in adults’naive B cell cultures. Although IgA produced by neonatal B cells was exclusively IgA1, IgA2‐secreting cells were identifiable in adult naive B cells. The results suggest that further class switch of naive B cells to IgG2, IgG4 and IgA2 in addition to IgG1 and IgG3 may be controlled by their own age‐dependent maturation process.