An aetiological role has been proposed for human papillomavirus (HPV) in skin carcinogenesis within the immunosuppressed patient population. To examine this possibility, we have focused on an HPV type that, to date, has been identified only in the cutaneous lesions of renal transplant recipients despite a high degree of sequence homology with other HPVs commonly found in warts in the general population. We report that the non-coding region of this virus, HPV type 77, contains a consensus binding site for the tumour suppressor protein p53, and we show by gel-retardation analysis that this sequence does indeed bind p53. Furthermore, using reporter gene assays, we demonstrate that HPV77 promoter activity is stimulated by UV radiation and that this response is mediated through the p53 binding site. This is the first report of a p53-dependent positive response element within a viral genome. Our results suggest a possible novel mechanism by which specific types of HPV might act as cofactors with UV radiation in cutaneous transformation.

The human T-cell leukemia virus HTLV-I is a transfusion-transmissible retrovirus targeting T lymphocytes for which screening is not currently undertaken in United Kingdom blood donors. The introduction of universal leukocyte depletion (LD) of the United Kingdom blood supply raises the question as to the degree of protection afforded by this procedure against HTLV-I transmission by blood components. HTLV-I viral DNA removal by leukocyte-depleting filters was assessed in units of whole blood and platelets by real-time quantitative polymerase chain reaction (PCR) and by nested PCR for HTLV-I Tax DNA. We examined HTLV-I removal by LD filters using a model system of blood units containing exogenous spiked HTLV-I-positive MT-2 cells at a relevant concentration and whole blood donations from asymptomatic HTLV-I carriers. T-lymphocyte removal was assessed in parallel by measurement of endogenous subset-specific CD3 mRNA. In the MT-2 model system we observed 3.5 log 10 to 4 log 10 removal of HTLV-I Tax DNA by filtration of whole blood and 2 log 10 to 3 log 10 removal across platelet filters with 13 of 16 whole blood and 8 of 8 platelet units still positive after filtration.Despite 3 log 10 to 4 log 10 viral removal, HTLV-I Tax DNA could be detected after whole blood filtration in asymptomatic carriers with viral loads above 10 8 proviral DNA copies/L. T-lymphocyte removal was also between 3.5 log 10 and 4.5 log 10 . HTLV-I provirus removal was incomplete in the model system and in asymptomatic carriers with viral loads greater than 10 8 copies/L. These results suggest that LD alone may not provide complete protection from HTLV-I transmission by transfusion. (Blood. 2002;100:677-681)

To assess removal of cytomegalovirus (CMV) by leukocyte depletion (LD) filters, we developed a spiking model of latent virus using peripheral blood mononuclear cells (PBMCs) infected by coculture with CMV-infected human fibroblasts. Infected PBMCs were purified by dual magnetic column selection and then spiked into whole blood units or buffy coat pools prior to LD by filtration. CMV load and fibroblast contamination were assessed using quantitative CMV DNA real-time PCR and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) of mRNA encoding the fibroblast-specific splice variant of prolyl-4-hydroxylase, respectively. After correcting for fibroblast-associated CMV, the mean CMV load was reduced in whole blood by LD from 7.42 10 2 to 1.13 copies per microliter (2.81 10 log reduction) and from 3.8 10 2 to 4.77 copies per microliter (1.9 10 log reduction) in platelets. These results suggest that LD by filtration reduces viral burden but does not completely remove CMV from blood components. (Blood. Introduction Primary cytomegalovirus (CMV) infection results in lifelong carriage of latent virus, notably in CD14 monocytes. 1 Reactivation of donor CMV following transfusion 2 is avoided by selecting CMV-seronegative donors for vulnerable patients. Because universal leukocyte depletion (LD) has been widely implemented, it is debated whether LD alone could provide equivalent protection. 3,4 Eight studies have shown no transmissions following prestorage LD, 5,6 but a recent study reports increased transmission from LD CMV-seropositive components. 7 Quantitative real-time polymerase chain reaction (PCR) has the dynamic range to assess CMV removal by LD, 8,9 but due to low copy number, we and others 9 have failed to detect viremia in seropositive donors, and even optimal CMV PCR would require virtually all leukocytes in an LD component (less than 10 6). 10 We found techniques reported to increase CMV copy number (pollen, 11-interferon, hydrocortisone, granulocyte-macrophage colony-stimulating factor [GM-CSF], and allogeneic cells 2) to be insufficiently robust for assessment of LD. We have previously used infected T lymphocytes and real-time PCR to assess human T-cell leukemia virus-I (HTLV-I) removal by LD. 12 A CMV-infected T-cell line has also been described to measure CMV removal, 13 but T cells are not a major physiological reservoir of CMV. We have therefore modified a previously described system 14 to generate CMV-infected mononuclear cells, including CD14 monocytes, for spiking into blood donations prior to LD. Study design With ethics committee approval and donor consent, 450-mL blood donations from 6 CMV-seronegative donors were collected into citrate phosphate dextrose. Peripheral blood mononuclear cells (PBMCs) were prepared from a 24 mL aliquot by density gradient separation (mean yield, 1.52 10 7 0.27 10 7) and cultured for 12 hours with 2 10 6 human embryonic fibroblasts infected with human CMV strain AD169. PBMCs were separated from fibroblasts by double selection using magnetic beads coate...

Real-time RT-PCR assays are suitable for analysis of subset removal during WBC reduction. There was no significant difference between the two whole-blood filters or between platelet filtration and apheresis in the removal of any WBC subset.

Summary: In tracing the source of an outbreak of foodpoisoning with Salmonella virchow a chicken-packing station and associated rearing farms were investigated. The serotype was found in chickens in 9 of the 14 rearing farms investigated and in the hatchery, but not in the breeding flocks supplying the hatchery. Several personnel on the farms were affected. The infection was most likely to have been introduced by contaminated feedingstuffs.