purification-of-pathogen-vacuoles-from-legionella-infected-phagocytes

Purification of Pathogen Vacuoles from <em>Legionella</em>-infected Phagocytes

The opportunistic pathogen Legionella pneumophila is an amoeba-resistant bacterium, which also replicates in alveolar macrophages thus causing the severe ...

Patients with psoriasis treated with psoralen-UV-A (PUVA) are at increased risk of skin cancer; however, the exact causes of this increased incidence are not well understood. It has been suggested that PUVA may increase expression of the tumorigenic agent human papillomavirus (HPV) in skin by directly stimulating virus replication, immune suppression, or both, thereby leading to skin cancer formation.

Increased prevalence of human papillomavirus in hairs plucked from patients with psoriasis treated with psoralen-UV-A.

Erh&#xF6;hte Pr&#xE4;valenz von HPV in Haaren von Patienten mit Psoriasis mit Psoralen-UV-A behandelt gezupft.

Using human skin explants, we investigated the effects of two different sunscreen preparations containing a chemical UVB filter alone [sun protection factor (SPF) 5.2] or UVA+UVB filter [SPF 6.2] on sunburn cell formation, dendritic cell (DC) migration, CD86- and CD1a-positive cell number, and tumor necrosis factor alpha (TNFalpha) and interleukin (IL)-1, IL-10, and IL-12 production in the skin after irradiation with different doses of solar-simulated UV radiation. Sunscreen- or placebo-treated skin explants were irradiated with solar-simulated UV radiation at 0.5, 1, and 2 minimal erythematous dose equivalents (MEDE) (as determined in an in vivo human study) multiplied by the SPF of the placebo or sunscreens. After irradiation, skin explants were floated on RMPI medium for 48 h. Cells that had emigrated and the skin explants were histologically analyzed, and the soluble mediators were measured in the supernatants by ELISA. Exposure to UV radiation led to concentration-dependent increases in sunburn cell formation and TNFalpha production but a concentration-dependent decrease in DC migration and CD86- and CD1a-positive cell number in the epidermis. Both chemical sunscreens protected against those alterations. The immunoprotective capacity of the sunscreens correlated with their SPF but was independent of the sunscreens' UVA protection capacity, suggesting that UVA is not a major factor for immunosuppression under the conditions used in the model. UV irradiation did not significantly affect the vitality of emigrated DC; the expression of HLA, CD80, and lag on emigrated cells; the number of CD1a-positive cells in the dermis; or the production of IL-1, IL-10, and IL-12. We conclude that our model may be useful in determining the immunoprotective capacity of sunscreens.

Sunburn cell formation, dendritic cell migration, and immunomodulatory factor production after solar-simulated irradiation of sunscreen-treated human skin explants in vitro.

Sonnenbrand Zellbildung, die Migration dendritischer Zellen, und immunmodulatorische Faktor Produktion nach Solar-simulierten Bestrahlung von Sonnenschutzmitteln-behandelten Explantaten der menschlichen Haut in vitro.

The development of substitutes for the human skin, e.g., artificial skin constructs (ASCs), is of particular importance for pharmaceutical and dermatologic research because they represent economical test samples for the validation of new drugs. In this regard, it is essential for the skin substitutes to be reliable models of the genuine skin, i.e., to have similar morphology and functionality. Particularly important is the barrier function, i.e., the selective permeability of the skin, which is strongly related to the epidermal pH gradient. Because the pH significantly influences the permeation profile of ionizable drugs such as nonsteroidal anti-inflammatory drugs, it is of major importance to quantitatively measure the epidermal pH gradient of the ASC and compare it to that of genuine skin.

3D-resolved investigation of the pH gradient in artificial skin constructs by means of fluorescence lifetime imaging.

In the past, natural scrapie and bovine spongiform encephalopathy (BSE) infections have essentially not been diagnosed in sheep homozygous for the A136R154R171 haplotype of the prion protein. This genotype was therefore assumed to confer resistance to BSE and classic scrapie under natural exposure conditions. Hence, to exclude prions from the human food chain, massive breeding efforts have been undertaken in the European Union to amplify this gene. We report the identification of 2 natural scrapie cases in ARR/ARR sheep that have biochemical and transmission characteristics similar to cases of classic scrapie, although the abnormally folded prion protein (PrP(Sc)) was associated with a lower proteinase-K resistance. PrP(Sc) was clearly distinct from BSE prions passaged in sheep and from atypical scrapie prions. These findings strongly support the idea that scrapie prions are a mosaic of agents, which harbor different biologic properties, rather than a unique entity.

Article	Year
The Journal of investigative dermatology\| PubMed ID: 14708610	2003
Increased prevalence of human papillomavirus in hairs plucked from patients with psoriasis treated with psoralen-UV-A. Archives of dermatology\| PubMed ID: 15023775	2004
Binocular vision & strabismus quarterly\| PubMed ID: 15320861	2004
Sunburn cell formation, dendritic cell migration, and immunomodulatory factor production after solar-simulated irradiation of sunscreen-treated human skin explants in vitro. The Journal of investigative dermatology\| PubMed ID: 15373785	2004
3D-resolved investigation of the pH gradient in artificial skin constructs by means of fluorescence lifetime imaging. Pharmaceutical research\| PubMed ID: 16028008	2005
The Journal of general virology\| PubMed ID: 17325380	2007
Veterinary microbiology\| PubMed ID: 17521831	2007
Classic scrapie in sheep with the ARR/ARR prion genotype in Germany and France. Emerging infectious diseases\| PubMed ID: 17953092	2007
Animal reproduction science\| PubMed ID: 18468817	2009
Alternatives to laboratory animals : ATLA\| PubMed ID: 18522484	2008
Alternatives to laboratory animals : ATLA\| PubMed ID: 18522485	2008
The Journal of general virology\| PubMed ID: 20538906	2010
The Journal of general virology\| PubMed ID: 20660146	2010
The Journal of general virology\| PubMed ID: 20943888	2011
Phytotherapy research : PTR\| PubMed ID: 21089181	2011
Journal of cell science\| PubMed ID: 21098633	2010
Veterinary research\| PubMed ID: 21314904	2011
European journal of cell biology\| PubMed ID: 21561684	2011
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fÃ¼r Pharmazeutische Verfahrenstechnik e.V\| PubMed ID: 21939763	2012
New directions for youth development\| PubMed ID: 22504792	2012

Christine Hoffmann

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