1. A Possible Role of Keratinocytes of Skin and Mucous Membranes in Prion Propagation and Transmission 
Johannes Pammer 
Journal of Investigative Dermatology Symposium Proceedings 
Volume 7, Issue 1, Pages (December 2002)
DOI: /j x
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

2. Figure 1
Ulcerations and hemorrhagic crusting on the hind leg of a sheep suffering from natural scrapie.
Journal of Investigative Dermatology Symposium Proceedings 2002 7, 59-63DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
PrPcis expressed by keratinocytes in inflammatory skin diseases. In contrast to regular human skin (panel A), keratinocytes are strongly positive for PrPc in inflammatory skin diseases such as psoriasis (panel B). In addition, mononuclear cells within the dermis and epidermis express PrPc. Immunohistochemical analysis in Figure 2 was performed as described previously (Pammer et al, 1998).
Journal of Investigative Dermatology Symposium Proceedings 2002 7, 59-63DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

4. Figure 3
PrPcexpression by human foreskin keratinocytes (passage 2–5) is upregulated by TGF-α. Western blot analysis of keratinocytes demonstrates that addition of TGF-α to the culture medium upregulates PrPc expression. The band at around 26 kDa corresponds to the nonglycosylated form of PrPc. Culture of keratinocytes and Western blot analysis were performed as described previously (Pammer et al, 1998;Weninger et al, 2000).
Journal of Investigative Dermatology Symposium Proceedings 2002 7, 59-63DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

5. Figure 4
PrPc is expressed in bovine skin. PrPc expression is readily observed in basal and suprabasal keratinocytes of regular bovine snout skin (Pammer et al, 1999).
Journal of Investigative Dermatology Symposium Proceedings 2002 7, 59-63DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

6. Figure 5
Possible steps in prion invasion and spread in the skin. (1) Breakdown of the cornified layer in inflammatory skin diseases and simultaneous upregulation of PrPc expression by epidermal keratinocytes could allow entry of prions and infection of keratinocytes. (2) Spread of prions to the central nervous system via intraepidermal sensory skin nerves. (3) Spread of prions to the lymphatic system by passenger leukocytes. (4) Transport of prions to the epidermis by infected leukocytes in the course of inflammatory skin diseases.
Journal of Investigative Dermatology Symposium Proceedings 2002 7, 59-63DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions