FDC-M2 staining is induced strongly in immunized but not <i>B</i>. <i>burgdorferi</i>-infected mice.

C57BL/6 mice were immunized with influenza virus in alum and/or infected with Bb as indicated. Draining lymph nodes were collected 10 days later and cryopreserved. Frozen sections were prepared and stained with anti-mouse IgD FITC and anti-FDC-M2 biotin and streptavidin-AlexaFluor594 as outlined in the main manuscript. Germinal centers within IgD positive follicles are identified as IgDlow/negative. Shown are images collected at 10x objective of FDC-M2 staining (red) overlayed with IgD (green, left column) and alone (white, right column). Influenza immunization (top row), but not Bb infection (bottom two rows), induced robust FDC-M2 staining. Thus, Bb-infection results in a lack of complement C4 deposition on FDC. (PDF)