Fig 4. Screening of C8 for immunohistologic recognition of CCL21 in a tonsilar lymphoid biopsy specimen.

Screening for binding of CCL21 in human lymphoid tissue. C8 was positive for binding to appropriate CCL21-expressing cells in human tonsil lymph node, while another monoclonal antibody in this series that failed screening in Fig 1 did not bind to any cells, indicating the utility of C8 as an immunohistologic tool (left panels). CCL21 is expressed in the venule endothelium of T-cell-mediated auto-immune skin diseases [15]. C8 specifically recognizes this expression in immunohistologic assays while it did not recognize synovium from rheumatoid arthritis serves as a negative control, as it is mediated by a distinct immunologic pathway (right panels).