IgG surrogate antigens tethered by H12-D-domain enhance the accumulation of BCR and pSyk into B cell immunological synapse than the ones tethered by streptavidin.

<p>(A) Statistical quantification for the mean fluorescence intensity (mFI) of biotin and Alexa 568-conjugated goat IgG anti human IgM surrogate antigens tethered on the surface of PLB membranes by either H12-D-domain (red color) or streptavidin (blue color). Each dot represents a single measurement for the mFI of the tethered IgG surrogate antigens by Image J software. Bars represent means ± SD. Two-tailed t tests were performed for statistical comparisons. (B) Statistical quantification for the accumulation of human IgM-BCRs into the immunological synapse as measured by the mFI of BCR within the immunological synapse from Ramos human B cells that were placed on PLB membranes presenting the same amount of IgG surrogate antigen as shown in A that were tethered by either H12-D-domain or streptavidin. Each dot represents a single measurement for the mFI of IgM-BCRs by Image J software. Bars represent means ± SD. Two-tailed t tests were performed for statistical comparisons. (C) Statistical quantification for the accumulation of pSyk signaling molecules into the immunological synapse as measured by the mFI of BCR within the immunological synapse from Ramos human B cells that were placed on PLB membranes presenting the same amount of IgG surrogate antigen as shown in A that were tethered by either H12-D-domain or streptavidin. Each dot represents a single measurement for the mFI of pSyk by Image J software. Bars represent means ± SD. Two-tailed t tests were performed for statistical comparisons.