involucrin and Condylomata-Acuminata

The cornified cell envelope (CCE) is an insoluble matrix of covalently linked proteins assembled in differentiating keratinocytes, providing a barrier against external insults. CCEs derived from HPV 11-infected tissue are fragile compared to those derived from healthy epithelium. To study a possible role for the E1()E4 protein, HPV 11-infected epithelium was examined for the distribution of this protein and three CCE proteins. CCEs were then purified from genital epithelium, fragmented, washed to remove nonassociated proteins, and analyzed for E1()E4 protein. In HPV 11-infected tissue, the E1()E4 protein was detected in the region of the CCE in differentiated keratinocytes. Loricrin and cytokeratin 10 (K10) were absent in E1()E4-positive cells, and E1()E4 protein was not detected in cells containing these proteins. E1()E4 protein was detected in immunoblots as a 10- to 11-kDa doublet in extracts of intact CCEs from infected tissue and in extracts of CCE fragments prepared without using reducing agents. Extraction with reducing agents eliminated E1()E4 detection, suggesting that disulfide bonding was involved in the association with CCE fragments. In addition, cyanogen bromide degradation experiments, immunofluorescence, and immunoelectron microscopy provided evidence that E1()E4 protein was associated with CCE fragments by covalent bonds other than disulfide bonds. We conclude that E1()E4 protein expression is associated with profound alterations in detection of loricrin and K10 in HPV 11-infected genital epithelium. The E1()E4 protein copurified with CCEs derived from infected epithelium and could be identified in CCE fragments, suggesting a possible role for E1()E4 in the development of CCE abnormalities.

Topics: Blotting, Western; Cells, Cultured; Condylomata Acuminata; DNA-Binding Proteins; Epithelium; Genital Diseases, Male; Genitalia, Male; Humans; Immunohistochemistry; Keratins; Male; Membrane Proteins; Microscopy, Immunoelectron; Oncogene Proteins, Viral; Papillomaviridae; Protein Precursors; Viral Proteins

Human papillomaviruses (HPVs) are important human pathogens associated with a range of epithelial neoplasia. The rising incidence of HPV infection and association of HPV with malignancy has led to increased interest in appropriate management of these infections. Development of new therapies for viral warts has been frustrated by the lack of availability of models permissive for viral replication. Here we describe the development of HPV-severe combined immunodeficient mouse model which reproduces mature HPV-infected epithelia. Grafting of anogenital and laryngeal papillomas harbouring either HPV-6 or HPV-11 resulted in the formation of a differentiated neo-epithelium exhibiting the hallmark features of HPV infection including basal hyperplasia, acanthosis and koilocytosis. The reformed warty epithelium contained amplified HPV DNA and expressed capsid protein in the differentiated layers. A striking feature is the production of macroscopic papillomata in an anatomically relevant and accessible site, providing a system of particular relevance for the temporal evaluation of developing lesions and selection of antiviral agents.

Topics: Animals; Capsid; Condylomata Acuminata; Disease Models, Animal; DNA Replication; Epithelium; Gene Expression; Humans; Keratins; Laryngeal Neoplasms; Mice; Mice, SCID; Neoplasm Transplantation; Papilloma; Papillomaviridae; Papillomavirus Infections; Proliferating Cell Nuclear Antigen; Protein Precursors; Skin; Skin Transplantation; Transplantation, Heterologous; Tumor Virus Infections; Virus Replication

Involucrin is a keratinocyte envelope protein precursor which is synthesized at an early stage of differentiation in normal squamous epithelium. Recent studies suggest that this protein may be a marker for neoplastic epithelium. To address this issue, we analyzed involucrin expression in 105 biopsies containing 119 areas of normal, condylomatous, and neoplastic epithelium. Overall, 88, 75, and 55% of condylomata, well-differentiated CIN, and poorly differentiated CIN (carcinoma in situ) contained positive staining for involucrin. Excluding lesions with severe inflammation, 100, 88, and 55% of these lesions, respectively, were positive. Staining patterns in neoplastic lesions differed from those in the normal epithelium and condylomata; the staining in CIN tended to be focal, and intensity of staining varied widely from cell to cell in all layers of the epithelium. In high grade CIN, staining correlated with increases in cell size and cytoplasmic differentiation. These studies suggest that involucrin will not differentiate between lesions of low versus high risk for progressing to invasive carcinoma. However, the patterns of involucrin expression confirm the marked differences in patterns of cellular differentiation between classical condylomata and CIN.

Topics: Condylomata Acuminata; Epithelium; Female; Histocytochemistry; Humans; Protein Precursors; Uterine Cervical Neoplasms

Ninety-three cervical conization specimens with condyloma or intraepithelial neoplasia were stained by the peroxidase-antiperoxidase technique for involucrin. Diffuse, homogeneous suprabasal staining was observed in the ectocervical squamous mucosa and mature squamous metaplasia. In immature squamous metaplasia, staining was limited to cells with apparent squamous differentiation. Although diffusely reactive in the upper layers of condyloma and cervical intraepithelial neoplasia (CIN) grade I, the stain was uneven in the former and lacking in the parabasal layers of the latter. The staining intensity, distribution, and pattern were more variable in CIN grade II and grade III. With increasing severity, a patchy pattern with a mixture of reactive and nonreactive cells predominated. Although immunoreactivity with involucrin could not distinguish immature squamous metaplasia from neoplasia, the staining patterns in CIN correlated with extent of disease, degree of squamous differentiation, and cellular disorganization.

Topics: Carcinoma in Situ; Carcinoma, Squamous Cell; Condylomata Acuminata; Female; Humans; Immunoenzyme Techniques; Protein Precursors; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms