Figure 6: GA binds to the BCR on human B cells from MS patients. (A) Similar to that observed in murine B lymphocytes, there are two GA positive binding populations. Shown is the gating strategy for determining GAlo and GAhi human B cells. (B) The percentage of B cells from 10 MS patients GAlo (left panel) or GAhi (right panel). (C) Human B lymphocytes from 6 MS patients were incubated with GA-488 alone (left panel), GA-488 followed by anti-Ig (middle panel), or anti-Ig followed by GA-488 (right panel). GA+ cells are separated into three populations, total GA+ cells, GA+ Ig intermediate cells labeled GA+ Igint, or GA+ Ighi cells. (D) The percent of human MS B cells GA+ Ig+ per indicated subset when GA-488 was pre-incubated with the B cells prior to the addition of anti-Ig. Data represents the average ± SD from six patients. (E) Preincubation with anti-Ig abrogates GA binding in the GA+ Ighi subset. Shown is the percent reduction in GA+ B cells per indicated subset when pre-incubated with anti-Ig prior to the addition of GA-488 compared to pre-incubation with GA-488 followed by anti-Ig.