Table 1.
List of analyzed TS samples.
Table 2.
Primary and secondary antibodies used for immunofluorescence.
Figure 1.
Histological features of trichodysplasia spinulosa.
Left column illustrates H&E staining of a low power field of healthy skin (A1) and TS lesional skin (B1). High power fields of healthy (A2) and TS (B2) epidermis and hair follicles (A3 and B3). Note the enlarged and dysmorphic hair follicle shown in B3, containing eosinophilic granular protein deposits in the cytoplasm of the cells (arrowheads in inset) with abrupt cornification in the center of the follicle. Bars depict 100 µm.
Figure 2.
Trichohyalin and Ki-67 expression in healthy and lesional skin.
This figure illustrates staining of trichohyalin (TCHH) and Ki-67 in healthy (A and B) and in TS skin (C, D and E). In the left panel, trichohyalin (A1) and Ki-67 (A2) staining in healthy epidermis and in healthy hair follicles (B1 and B3) are shown, with the corresponding levels of the follicle illustrated in B2. In the middle panel, trichohyalin (TCHH) and Ki-67 staining in TS lesional skin are shown with TS epidermis on top (C1 and C2) and vertical sections of TS hair follicle beneath (D1 and D2). Dotted lines indicate the dermoepidermal junction. Costaining for trichohyalin (green) and Ki-67 (red) of a TS follicle cross-sectioned at the suprabulbar region is shown in the right panel (E1–E3). Bars depict 100 µm.
Figure 3.
Cell cycle regulation markers and TSPyV LT-antigen expression.
Sections of healthy epidermis (A1–A4), healthy hair follicle (B1–B4), TS epidermis (C1–C4) and TS follicle (D1–D4) are stained for p16ink4a (first panel), p21waf (second panel), pRB (third panel) and TSPyV (fourth panel). Insets in the fourth panel depict the same region with Hoechst DNA staining (blue). Dotted lines indicate the dermoepidermal junction. Bar depicts 100 µm.
Figure 4.
Colocalization of TSPyV LT-antigen, Ki-67 and phosphorylated pRB.
TSPyV LT-antigen (red) (A1) with Ki-67 (green) (A2) and merge (yellow) (A3) in a vertical section of hair follicle of TS10 is shown in the upper row. A higher magnification of TSPyV LT-antigen (B1) with Ki-67 (green) (B2) and merge (yellow) (B3) in a suprabulbar cross-sectioned hair follicle region of TS5 is shown in the middle. B3 inset depicts the same region with Hoechst DNA staining (blue). Ki-67 (red) (C1) with phosphospecific (Ser807/811) pRB (green) (C2) and merge (yellow) (C3) in a suprabulbar cross-sectioned hair follicle region of TS5 is shown in the last row. A higher magnification of TS5 margin (C3, asterisk) is shown in the inset. Dotted lines indicate the dermoepidermal junction. Bars depict 100 µm.
Table 3.
Overview of cellular and virus markers detected in TS lesions.
Figure 5.
A hypothetical scenario of TSPyV LT-antigen interference in cell cycle regulation.
An oversimplified cell-cycling scenario is shown that envisions the TSPyV LT-antigen involvement in regulation of pRB pathway activity. In a normal physiological condition, hypophosphorylated pRB is complexed with transcription factor E2F during early G1 (rest) phase of the cell cycle. When pRB is hyperphosphorylated at specific residues by Cyclin-dependent kinases (CDK) coupled to Cyclin-D1, E2F is released that activates expression of growth stimulatory genes needed for the cells to enter the S (DNA synthesis) phase. pRB phosphorylation is under tight regulation of p16ink4a and p21waf. Hypothetically, through its conserved LXCXE motif TSPyV LT-antigen interacts with pRB/E2F complex to dissociate these proteins via pRB hyperphosphorylation, resulting into S phase entry and subsequent increased expression of p16ink4a and p21waf as a negative cell cycling feedback (red arrows).