Ann Dermatol.  2009 Nov;21(4):337-344. 10.5021/ad.2009.21.4.337.

Expression of Toll-like Receptor 2 in Cultured Human Keratinocytes: The Effect of Bacterial Antigens, Cytokines and Calcium Concentration

• Lew BL
• Sim WY
• Kim NI

• KMID: 2156494
• DOI: http://doi.org/10.5021/ad.2009.21.4.337

Abstract

BACKGROUND
Toll-like receptors (TLRs) are expressed by human epidermal keratinocytes and are involved in immune responses.
OBJECTIVE
The goal of this was to investigate the expression of TLR2 in response to bacterial antigens, cytokines, and different calcium concentrations.
METHODS
The expression of TLR2 was assessed after stimulation by lipoteichoic acid (LTA) and streptolysin O (SLO). In addition, TLR2 expression was evaluated after treatment with IFN-gamma and TNF-alpha, and different concentrations of calcium. The expression levels of TLR2 mRNA and protein were studied using RT-PCR and Western blot analysis.
RESULTS
Cultured human epidermal keratinocytes constitutively expressed TLR2 and the expression was stimulated by LTA and SLO; in addition, IFN-gamma and TNF-alpha upregulated TLR2 expression. However, the changes in TLR2 expression associated with the calcium concentrations were insignificant.
CONCLUSION
TLR2 expression increased with the concentration and duration of bacterial pathogens and this increase was amplified by several cytokines, from activated keratinocytes and other cells.

Keyword

Calcium; Cytokine; Keratinocyte; Microbacterial antigen; Toll-like receptor 2

MeSH Terms

Antigens, Bacterial
Bacterial Proteins
Blotting, Western
Calcium
Cytokines
Humans
Keratinocytes
Lipopolysaccharides
RNA, Messenger
Streptolysins
Teichoic Acids
Toll-Like Receptor 2
Toll-Like Receptors
Tumor Necrosis Factor-alpha
Antigens, Bacterial
Bacterial Proteins
Calcium
Cytokines
Lipopolysaccharides
RNA, Messenger
Streptolysins
Teichoic Acids
Toll-Like Receptor 2
Toll-Like Receptors
Tumor Necrosis Factor-alpha

Figure

• 

  Fig. 1 (A) TLR2 mRNA expression levels at 0.1 µg/ml, 1 µg/ml and 10 µg/ml of LTA compared to the control group for 3 hrs and 24 hrs (n=3, *p<0.05 when compared to the control). (B) TLR2 protein expression levels at 0.1 µg/ml, 1 µg/ml and 10 µg/ml of LTA for 3 hrs and 24 hrs compared to the control group (n=3, *p<0.05 when compared to the control).

• 

  Fig. 2 (A) TLR2 mRNA expression levels at 0.1 U/ml, 1 U/ml and 10 U/ml of SLO compared to the control group at 3 hrs and 24 hrs (n=3, *p<0.05 when compared to the control). (B) TLR2 protein expression levels at 0.1 U/ml, 1 U/ml and 10 U/ml of SLO for 3 hrs and 24 hrs (n=3, *p<0.05 when compared to the control).

• 

  Fig. 3 (A) TLR2 mRNA expression levels after treatment with IFN-γ (10 ng/ml, 50 ng/ml and 100 ng/ml) for 6 hrs and 24 hrs compared to the control group (n=3, *p<0.05 when compared to the control). (B) TLR2 protein expression levels at 10 ng/ml, 50 ng/ml and 100 ng/ml of IFN-γ for 6 hrs and 24 hrs (n=3, *p<0.05 when compared to the control).

• 

  Fig. 4 (A) TLR2 mRNA expression levels after treatment with TNF-α (10 ng/ml, 50 ng/ml and 100 ng/ml) compared to the control group for 6 hrs and 24 hrs (n=3, *p<0.05 when compared to the control). (B) TLR2 protein expression levels at 10 ng/ml, 50 ng/ml and 100 ng/ml of TNF-α for 6 hrs and 24 hrs (n=3, *p<0.05 when compared to the control).

• 

  Fig. 5 (A) TLR2 mRNA expression levels according to the calcium concentration (0.05 mM, 0.1 mM, and 0.2 mM) in cultured human keratinocytes at 6 hrs and 24 hrs (n=3). (B) TLR2 protein expression levels according to the calcium concentration (0.05 mM, 0.1 mM, and 0.2 mM) in cultured human keratinocytes at 6 hrs and 24 hrs (n=3).

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