alpha-Fetoprotein as a modulator of the pro-inflammatory response of human keratinocytes.
OBJECTIVE
The immunomodulatory effects of alpha-fetoprotein (AFP) on lymphocytes and macrophages have been described in vitro and in vivo. Recombinant forms of human AFP have been proposed as potential therapeutic entities for the treatment of autoimmune diseases. We examined the effects of embryonic and recombinant human AFP on the spontaneous, UVA- and cytokine-induced pro-inflammatory responses of human keratinocytes.


METHODS
Cultures of primary and immortalized human keratinocytes (HaCaT) and human blood T lymphocytes were used. The effects of AFP on cytokine expression were studied by bioplexed elisa and quantitative reverse transcriptase polymerase chain reaction assay. Kinase and nuclear factor kappa B (NFkappaB) phosphorylation were quantified by intracellular elisa. Nuclear activator protein 1 and NFkappaB DNA binding activity was measured by specific assays. Nitric oxide and H(2)O(2) production and redox status were assessed by fluorescent probe and biochemical methods.


RESULTS
All forms of AFP enhanced baseline expression of cytokines, chemokines and growth factors. AFP dose-dependently increased tumour necrosis factor alpha-stimulated granulocyte macrophage colony stimulating factor and interleukin 8 expression and decreased tumour necrosis factor alpha-induced monocyte chemotactic protein 1 and IP-10 (interferon gamma-produced protein of 10 kDa) expression. AFP induced a marked activator protein 1 activation in human keratinocytes. AFP also increased H(2)O(2) and modulated nitrite/nitrate levels in non-stimulated keratinocytes whereas it did not affect these parameters or cytokine release from UVA-stimulated cells. Phosphorylation of extracellular signal-regulated kinase (ERK1/2) and Akt1 but not NFkappaB was activated by AFP alone or by its combination with UVA.


CONCLUSIONS
Exogenous AFP induces activation of human keratinocytes, with de novo expression of a number of pro-inflammatory mediators and modulation of their pro-inflammatory response to cytokines or UVA. AFP may modulate inflammatory events in human skin.
Lab Tissue Engineering and Skin Pathophysiology, Dermatology Institute (Istituto Dermopatico dell'Immacolata, IDI IRCCS), Rome, Italy.
A I
AI
Potapovich
S
S
Pastore
V A
VA
Kostyuk
D
D
Lulli
V
V
Mariani
C
C
De Luca
E I
EI
Dudich
L G
LG
Korkina
D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis*; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D056747:Immunomodulation; D018836:Inflammation Mediators / Q000378:metabolism*; D007371:Interferon-gamma / Q000096:biosynthesis; D015603:Keratinocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism / Q000528:radiation effects; D009569:Nitric Oxide / Q000378:metabolism; D010766:Phosphorylation; D014176:Protein Biosynthesis; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D014466:Ultraviolet Rays; D000509:alpha-Fetoproteins / Q000494:pharmacology / Q000502:physiology*
D016207:Cytokines; D018836:Inflammation Mediators; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D000509:alpha-Fetoproteins; D009569:Nitric Oxide; D007371:Interferon-gamma; D006861:Hydrogen Peroxide; C494918:AKT1 protein, human; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases