FIG. 2.

Immunohistochemical staining for K15. HEK 293 cells were transfected with either pCR3.1 vector-only control (A) or the full-length eight-exon P form of K15 (B). (C) High-power (×100) magnification of panel B. Cells were then fixed and stained with the anti-K15 MAb 3B5/D7 (1:200). (E to G) K15 staining of KSHV-positive PEL cell lines BC3 (F) and JSC-1 (G) and negative control cell line Raji (E). (D) LNA-1 staining of plasmablasts in KSHV-associated MCD with characteristic nuclear stippling. (H) K15 staining of an adjacent section shows that all the plasmablasts also express K15 with characteristic cytoplasmic staining.