Selection of B lymphocytes in the periphery is determined by the functional capacity of the B cell antigen receptor.
Within the B cell antigen receptor (BCR), the cytoplasmic tails of both Igalpha and Igbeta are required for normal B cell development and maturation. To dissect the mechanisms by which each tail contributes to development in vivo, Igbeta(-/-) mice were reconstituted with retroviruses encoding either wild-type Igbeta, an Igbeta molecule lacking a cytoplasmic tail (Igbeta(deltaC)) or one in which the cytoplasmic tail was derived from Igalpha (Igbeta(Calpha)). All constructs rescued B cell development and generated immature B cell populations in the bone marrow with similar expression levels of both Igbeta and membrane-bound IgM. In the periphery, receptor-surface density was inversely proportional to the number of Igalpha tails in the BCR. Although peripheral-surface-receptor levels differed, splenic B cells expressing either Igbeta or Igbeta(Calpha) responded similarly to stimulation through the BCR. Analysis of membrane-bound IgM and Igbeta expression revealed that peripheral-receptor expression was primarily determined by positive selection between the bone marrow and peripheral immature B cell populations. These data indicate that B cells are selected into the periphery on the basis of a common level of antigen responsiveness.
Wang
Leo D
LD
Section of Rheumatology and Committee on Immunology, Biological Sciences Division and Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA.
Lopes
Jared
J
Cooper
A Byron
AB
Dang-Lawson
May
M
Matsuuchi
Linda
L
Clark
Marcus R
MR
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002455:Cell Division; D002460:Cell Line; D005434:Flow Cytometry; D051379:Mice; D008807:Mice, Inbred BALB C; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*
D011947:Receptors, Antigen, B-Cell