Analysis of human ß-papillomavirus and Merkel cell polyomavirus infection in skin lesions and eyebrow hair bulbs from a cohort of patients with chronic lymphocytic leukaemia.

BACKGROUND: Research demonstrates an increased incidence of skin cancer in immunocompromised hosts, including patients with chronic lymphocytic leukaemia (CLL) and organ transplant recipients (OTRs). Active human ß-papillomavirus (ß-HPV) infection has been found in OTR skin lesions, suggesting its possible involvement in skin carcinogenesis. Merkel cell polyomavirus (MCPyV) has also been reported in cases of skin cancer. OBJECTIVES: To investigate the potential correlations between patient clinical features and skin cancer development, and the presence of ß-HPV and MCPyV DNA and protein markers in skin lesions and hair bulbs from patients with CLL. METHODS: The clinical features of 293 patients with CLL were analysed according to the presence or absence of skin lesions. ß-HPV and MCPyV infection was investigated in skin lesions and hair bulbs from the study cohort by both polymerase chain reaction (PCR) analysis and immunohistochemical screening. RESULTS: No significant correlations were observed between any of the analysed haematological parameters and the development of skin cancer. PCR analysis revealed the presence of ß-HPV and MCPyV DNA in skin lesions, and 83% of positivity for MCPyV DNA in hair bulbs, while systematic immunohistochemical analysis of all the lesions failed to detect any expression of the viral proteins ß-HPV E4, L1 or MCPyV LTAg. CONCLUSIONS: Overall, the data indicate that carriage of ß-HPV and MCPyV in the lesional skin and hair bulbs from patients with CLL without any evident reactivation at skin tumour sites most likely represents coincidental rather than causal infection. This contrasts with previous findings in relation to OTR-derived skin lesions.

Characterization of skin lesions induced by skin-tropic α- and ß-papillomaviruses in a patient with epidermodysplasia verruciformis.

Epidermodysplasia verruciformis (EV) is a rare, lifelong, autosomal recessive skin disease associated with an unusual susceptibility to infections with ubiquitous ß-human papillomaviruses (ß-HPVs), and in some cases also skin-tropic α genotypes. In this case report, HPV infection patterns were correlated with pathology and clinical manifestations of skin lesions from a patient with EV, without loss-of-function mutations in the EVER genes. HPV infection was investigated by both polymerase chain reaction (PCR) and laser capture microdissection (LCM) PCR, alongside immunofluorescence for the viral proteins E4 and L1. Analysis of eyebrow hair bulbs revealed multiple ß-genus HPV infections, including HPV20 and HPV24, which were consistently found in all 11 skin lesions on the patient. Six lesions were also positive for the skin tropic α-genotype, HPV27. Clear-cut differences between two wart-like lesions, one caused by a skin-tropic α-genotype and the other by ß-genotypes (as detected by LCM PCR) are shown, including the high cellular proliferation rate in ß-HPV-induced lesions. Widespread expression of the early protein E4 was also evident in skin lesions positive for HPV20 by LCM PCR in both tumours and nearby intraepidermal proliferative areas. L1 expression was restricted to areas of intraepidermal proliferation showing productive infection. The patient's inability to control HPV infections is conclusive to the uncontrolled replication of few genotypes from both α and ß genera, which cause proliferative lesions with clear-cut clinical and histological features.

Redistribution of the nuclear protein IFI16 into the cytoplasm of ultraviolet B-exposed keratinocytes as a mechanism of autoantigen processing.

BACKGROUND: The skin has long been recognized as a prominent target tissue in systemic lupus erythematosus (SLE) which plays a crucial role in the initiation and perpetuation of the autoimmune reaction cascade as a consequence of ultraviolet (UV)-induced keratinocyte apoptosis. Antibodies against IFI16 (interferon-inducible protein 16) have been detected in the sera of patients with SLE. OBJECTIVES: To verify whether the induction of autoimmunity against IFI16 involves redistribution of this nuclear protein in keratinocytes during UVB-induced cell death. METHODS: An in vitro epidermal model was developed to investigate the fate of the IFI16 protein in keratinocytes after irradiation with UVB; both keratinocyte monolayers and human skin explants were used. IFI16 expression and localization were also analysed in diseased skin sections of patients with SLE. RESULTS: We demonstrated that IFI16, normally restricted to the nucleus, can be induced to appear in the cytoplasm under conditions of UVB-induced cell injury. This nucleus to cytoplasm translocation was also observed in skin explants exposed to UVB and in the diseased skin sections from patients with SLE. In addition, IFI16 was found in the supernatants of UVB-exposed keratinocytes. CONCLUSIONS: The finding that IFI16 is present in the cytoplasm of diseased skin cells from patients with SLE and the demonstration of IFI16 in the supernatants of UVB-exposed keratinocytes, suggest that UVB irradiation or other stimuli may favour an abnormal IFI16 presentation to the afferent limb of the immune system and potentially an autoimmune response against the protein itself.