Defective assembly of Ig M and CD79b chains in chronic lymphocytic leukemia (CLL) patients.

Peripheral blood lymphocytes (PBLs) from four CLL patients, purified normal B cells or Daudi cells were fixed with PFA, permeabilized with saponin and co-labeled with anti-m Ab together with anti-CD79b Ab. The m chain was detected with a secondary Ab conjugated with Alexa 546 (red), the CD79b chain was detected with an Ab conjugated with FITC followed by an Ab conjugated with Alexa 488 (green). Yellow color at merged images indicates co-localization of the m and CD79b. It is shown that whereas m and CD79b co-localize in normal and Daudi B cells, co-localization is impaired in the case of CLL B cells.