| 1. |
- Pivarcsi, Andor, et al.
(författare)
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Differentiation-regulated expression of Toll-like receptors 2 and 4 in HaCaT keratinocytes.
- 2004
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Ingår i: Archives of Dermatological Research. - : Springer Science and Business Media LLC. - 0340-3696 .- 1432-069X. ; 296:3, s. 120-4
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Tidskriftsartikel (refereegranskat)abstract
- Toll-like receptors (TLRs) play an important role in the recognition of pathogens in keratinocytes. In this study, we investigated whether the differentiation state of HaCaT keratinocytes correlates with the expression of TLR2 and TLR4 genes. The expression levels of TLR2 and TLR4 in a HaCaT differentiation model system were determined using quantitative real-time RT-PCR (Q-RT-PCR) and flow cytometry. The progression of keratinocyte differentiation was monitored by determining the level of involucrin gene expression using Q-RT-PCR. The expression levels of TLR2 and TLR4 increased with the stage of differentiation and there were strong correlations between the expression level of the involucrin gene and those of the TLR2 gene ( r=0.809, P<0.0001) and the TLR4 gene ( r=0.568, P<0.02). Increased cell surface expression of TLR2 and TLR4 was also found in differentiated HaCaT keratinocytes by flow cytometric analysis. Our findings suggest that upregulation of TLR expression during differentiation in keratinocytes could be a part of the differentiation process of keratinocytes and could have biological significance in protecting skin against microbes.
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| 2. |
- Pivarcsi, Andor, et al.
(författare)
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Expression and function of Toll-like receptors 2 and 4 in human keratinocytes.
- 2003
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Ingår i: International Immunology. - : Oxford University Press (OUP). - 0953-8178 .- 1460-2377. ; 15:6, s. 721-30
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Tidskriftsartikel (refereegranskat)abstract
- Keratinocytes have the ability to kill pathogenic fungi and bacteria by producing antimicrobial substances. Recent studies suggest that microbial components use signaling molecules of the human Toll-like receptor (TLR) family to transduce signals in various cells. Here we provide evidence that keratinocytes express both TLR2 and TLR4 at the mRNA and protein levels, and show that TLR2 and TLR4 are present in the normal human epidermis in vivo and that their expression is regulated by microbial components. The expression of myeloid differentiation protein gene (MyD88), which is involved in the signaling pathway of many TLR, was also demonstrated in keratinocytes. LPS + IFN-gamma increased the expression of TLR2 and TLR4 50- and 5-fold respectively. Treatment of keratinocytes with Candida albicans, mannan, Mycobacterium tuberculosis or LPS with IFN-gamma resulted in the activation and nuclear translocation of NF-kappaB. Inhibition of NF-kappaB blocked the Candida-killing activity of keratinocytes, suggesting that the antimicrobial effect of keratinocytes requires NF-kappaB activation. LPS + IFN-gamma, C. albicans (4 Candida/KC), peptidoglycan (1 micro g/ml) or M. tuberculosis extract significantly increased IL-8 gene expression after 3 h of treatment (P < 0.05). The increases over the 0-h level were 15-, 8-, 10.8- and 7-fold, respectively. The microbial compound-induced increase in IL-8 gene expression could be inhibited by anti-TLR2 and anti-TLR4 neutralizing antibodies, suggesting that TLRs are involved in the pathogen-induced expression of this pro-inflammatory cytokine. Our findings stress the importance of the role of keratinocytes as a component of innate immunity.
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| 3. |
- Westberg, Lars, et al.
(författare)
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Resource management in Diffserv (RMD) : A functionality and performance behavior overview
- 2002
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Ingår i: Protocols for High Speed Networks. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783540436584 - 9783540478287 - 3540436588 ; , s. 17-34
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Bokkapitel (refereegranskat)abstract
- The flexibility and the wide deployment of IP technologies have driven the development of IP-based solutions for wireless networks, like IP-based Radio Access Networks (RAN). These networks have different characteristics when compared to traditional IP networks, imposing very strict requirements on Quality of Service (QoS) solutions, such as fast dynamic resource reservation, simplicity, scalability, low cost, severe congestion handling and easy implementation. A new QoS framework, called Resource Management in Differentiated Services (RMD), aims to satisfy these requirements. RMD has been introduced in recent publications. It extends the IETF Differentiated Services (Diffserv) architecture with new admission control and resource reservation concepts in a scalable way. This paper gives an overview of the RMD functionality and its performance behavior. Furthermore, it shows that the mean processing delay of RMD signaling reservation,messages is more than 1330 times smaller then the mean processing delay of RSVP signaling reservation messages.
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