Adaptive Immune Response to Model Antigens Is Impaired in Murine Leukocyte-Adhesion Deficiency-1 Revealing Elevated Activation Thresholds In Vivo
Figure 3
No induction of GC with NP21-CG specificity after immunization in CD18−/− mice. Two weeks after immunization, spleens and BM of WT and CD18−/− mice were subjected to immunofluorescence microscopy (spleens; (a), (b)) or flow cytometry (BM, spleens; (c), (d)). B-cell follicles identify as IgD+ (b) or IgM+ (a) (both in red), whereas GC locate within the follicles and stain IgD- GL-7+ (a) or IgM- PNA+ (b) (GL-7 and PNA both in green). Specificity for NP-CG was assessed by staining with NP-CG-Cy5 (blue). (a) and (b) show representative sections of spleens solely from immunized mice. Scale bars, 500 μm. Spleen ((c); (d), upper histograms) or BM ((d), lower histograms) cells were analyzed by FACS. (c) displays representative dot plots of splenic cells gated for CD19+ IgMlow. B cells with a GC phenotype additionally stain positive for GL-7 and are situated in the right quadrants of each plot. GC B cells with specificity for NP-CG are located in the upper right quadrants. Percentages for size-gated cells are indicated for immunized (upper dot plots) and mock-immunized (lower dot plots) mice. (d) shows representative histogram plots of cells gated for CD19+ IgMlow GL-7+, representing GC B cells. The continuous lines indicate samples obtained from mice immunized with NP21-CG; dashed lines: mock-immunized mice; grey areas: irrelevant control conjugates.
