Persistent Polyclonal B Cell Lymphocytosis B Cells Can Be Activated through CD40-CD154 Interaction

Figure 4

PPBL B cells can morph into IgG secreting cells following long-term CD154 stimulation. B cells stimulated with a low level of CD154 interaction (Figure 2) were analyzed for their ability to express and secrete IgG. (a) The proportion of IgG⁺ within CD19⁺ cells before (0 d) and after exposure to a low level of CD154 interaction (8 d and 13 d for 8030 and 9 d and 14 d for 8010 and 8011) was determined by flow cytometry. These phenotypes are representative of the six analyzed samples. (b) IgG and IgM secretion rates were determined at the end of the culture periods on all samples (patients and healthy controls).

(a)

(b)