A critical role of Lyn and Fyn for B cell responses to CD38 ligation and interleukin 5

摘要

CD38 ligation on mouse B cells by CS/2, an anti-mouse CD38 mAb, induced proliferation, interleukin 5 (IL-5) receptor chain expression, and tyrosine phosphory- lation of Bruton tyrosine kinase (Btk) from wild-type, but not from X chromosome-linked, immunodeficient mice. B cells from fyn-deficient (Fyn~-/-) and lyn-deficient (Lyn~-/-) mice showed an impaired response to mAb CS/2 for proliferation and IL-5 receptor chain expression, and B cells from fyn/lyn double-deficient (Fyn/Lyn~-/-) mice did not respond at all to mAb CS/2. The Btk activation by CD38 ligation was observed in B cells from Fyn~-/- mice, and it was severely impaired in B cells from Lyn~-/- and Fyn/Lyn~-/- mice.