Lack of expression of Syk, Lck, CD52, and RP105 in reactive tonsils and primary HRS cells.

Immunohistochemical stainings on reactive tonsils (A-D) and lymph node sections of patients with cHL (E-H) for Syk (A,E), Lck (B,F), RP105 (C,G), and CD52 (D,H). Expression in reactive tonsils: In line with previous studies, in tonsil sections, RP105 was found to be strongly expressed in mantle zone cells and weakly in GC cells. In addition, some interfollicular cells show positivity for RP105. Syk was detected in GC, mantle zone, and many interfollicular cells. High expression of Lck was detected in interfollicular cells, probably T cells, GC cells, and some mantle zone cells. CD52 was expressed in many GC cells, in mantle zone cells, and in many interfollicular cells. Expression in primary HRS cells was measured in consecutive sections stained with anti-CD30 to analyze for morphology and frequency of HRS cells in lymph nodes (not shown). In the stainings for RP105, Syk, CD52, and Lck, HRS cells (indicated by a black arrow or shown with a higher magnification in insets [E-F,H]) were identified according to morphologic criteria. In panel F, the inset shows a different HRS cell than indicated in the overview. No protein expression of Syk and CD52 was detected in HRS cells in any of the cases investigated, although surrounding cells showed positivity. Lck and RP105 expression was found only in one investigated case each, with only some HRS cells showing protein expression (shown are negative cases). Syk and CD52 was stained using Fast Red substrate (red). Lck and RP105 were stained using DAB staining (brown). Original magnifications: × 100 (A, C); × 200 (B, D); and × 400 (E-H). Insets and some panels were magnified using Photoshop software (Adobe Systems, San Jose, CA).