The TGM1 gene encodes the TGase 1 enzyme which is an essential component in the formation of a functional epidermal barrier [29, 141]. Mutations in the TGM1 gene have been associated with autosomal recessive lamellar ichthyosis (OMIM#242300) and non-bullous congenital ichthyosiform erythroderma (OMIM#242100), both skin disorders that are characterized by severe epidermal abnormalities. Furthermore, tgm1 null mice show impaired barrier function and die at birth [142].
Given these findings, and the fact that the TGM1 gene is located in a chromosomal region which has previously been linked to eczema [60], we set out to study the expression of this gene in eczema patients and to test whether genetic variation at the TGM1 locus influences the susceptibility to eczema.
We first analyzed the mRNA expression of the TGM1 gene and found significantly higher expression in lesional and non-lesional skin from atopic eczema patients as compared to healthy individuals (figure 8).
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0
Lesional
eczema Non-lesional eczema Healthy
controls p=0.02 p=0.02
TGM1relative mRNA expression
Figure 8. TGM1 mRNA levels in atopic eczema patients and healthy controls. Horizontal bars represent the group median.
IHC analysis was then used to study the expression of the TGase 1 protein and we found a markedly increased TGase 1 expression in lesional skin, and although less evident, there also appeared to be an increase in non-lesional skin from atopic eczema
expression of the TGM1 gene in lesional skin from atopic eczema patients is part of the dysregulated expression pattern found in skin of these patients. Increased TGM1 expression has also been found in the skin of psoriasis patients [143], and may therefore be a reflection of the increased epidermal turn-over found in this diseases.
One may speculate that the increased expression of TGM1 could be a part of the pathogenetic mechanism in these diseases or a part of a compensatory mechanism aimed at restoring the epidermal barrier. However, further studies are needed to resolve this issue.
In the genetic association study the Swedish family material was genotyped for eight SNPs covering the TGM1 locus. One SNP in the 5’ region, rs941505, was significantly associated with atopic eczema, p=0.003 (paper IV, table I). Accordingly, in the haplotype analysis we found a significant association (p=0.005) for the CCTG haplotype (see table 8), tagged by the minor allele of rs941505 (T), in LD block 2 of the gene.
Haplotypes rs2748516 rs2273301 rs941505 rs729421
Eczema Atopic eczema Non-atopic eczema
Block 2 HF OR P OR P OR P
C C A A 0.564 1.14 (0.97-1.34)
0.09 1.22
(1.01-1.47) 0.03 (NS)
0.97 (0.73-1.27)
0.81
C C A G 0.212 0.92 (0.77-1.11)
0.37 0.96
(0.76-1.20)
0.70 0.90 (0.67-1.19)
0.44
C C T G 0.096 0.83 (0.82-1.07)
0.16 0.61 (0.42-0.87)
0.005 (0.03)
1.23 (0.80-1.89)
0.36
C T A G 0.061 0.94 (0.68-1.29)
0.71 0.86
(0.57-1.28)
0.45 1.20 (0.74-1.94)
0.44
T C A A 0.057 1.00 (0.72-1.37)
1 0.98
(0.66-1.43)
0.90 0.99 (0.56-1.73)
0.96
Table 8. Results of Pedigree Disequilibrium Test for the inferred TGM1 haplotypes in the Swedish eczema families.1Haplotype Frequency (HF) in the whole material. 2Odds ratio (OR) of haplotype relative to all the other haplotypes together, 95% confidence intervals in brackets.
Permutated p-values given within brackets, NS = non-significant.
developing atopic eczema. The TGM1 SNP rs941505 is positioned in a evolutionary conserved part of the predicted promoter region [144] and in silico analysis suggest that this SNP alters putative binding site of transcription factors overlapping this position [144]. However, several putative SNPs map in the promoter region and additional may exist. Further studies will be needed to determine the actual disease causing variant in this region.
5 CONCLUDING REMARKS
The work presented in this thesis has been aimed at identifying new factor involved in eczema barrier dysfunction. Figure 9 provides a schematic overview of the main factors believed to be involved in barrier dysfunction together with some of those investigated in our studies.
We identified a higher expression of the TGM1 gene in eczema patients compared to healthy controls and our results suggest that genetic variability at this locus plays a role in eczema susceptibility. The variation at the TGM1 locus is associated with atopic eczema while no association was seen with nonatopic eczema. Similar patterns were observed for the FLG variants and in the CRNN study. This implies that barrier dysfunction determined by variants at these loci may lead to increased penetration of allergen and thereby increase the risk of sensitization. However, the subdivision of eczema into atopic and nonatopic has been questioned and further studies are clearly needed to delineate this complex disease. Sequencing of the TGM1 region is now planned in an effort to identify variants that might provide additional information about the association. Independent sets of patients and controls will also be analyzed to confirm the association. Furthermore, since the filaggrin protein and TGase 1 enzyme play key roles in the process leading to the formation of the cornified envelope it would also be interesting to test the combinatory effect of different genotypes at these loci and other loci involved in the same process. The role of CRNN and other genes in the EDC region in eczema needs to be studied further. It is likely that the study of genetic variation in this region may yield additional clues in eczema pathogenesis. However, due to the extensive LD in the region, this might represent a particularly challenging task to elucidate. The function of CRNN is poorly understood. One might hypothesize that the reduced expression found in the skin of eczema patients could be linked to the increased apoptosis of keratinocytes and it would therefore be interesting to correlate the expression to known markers of apoptosis. Furthermore, the production of transgenic mice where the expression could be correlated to phenotypic changes would also be a valuable tool.
Overall, our results support the notion that genetically determined dysfunction of the physical barrier in the epidermis is an important factor in eczema. Allergen penetration, determined by genetic or environmental factors, through the upper layer of the epidermis will lead to the production of primary cytokines from keratinocytes that help
system, antigen presenting DCs in eczema patients may respond differently to allergen stimulation compared to DCs from healthy individuals. The response seen in some of the patients, e.g. a high production of IL-8 and MDC, will increase the influx of T cells and other inflammatory cells from the circulation and could thereby exaggerate the inflammation.
Genetic factors:
FLG, SCCE, COL29A1,TGM1?
MDCIL-8 CCL17CCL2
GM-CSF TSLPIL-1 CCL27
IL-18
CD83
CD83 Dysregulated
genes:
TGM1FLG LoricrinCRNN S100A8 etc…
Figure 9. Schematic overview of some of the factors involved in barrier dysfunction in eczema.
Modified from Maintz et al [103]. Abbreviations: AMP = antimicrobial peptides; CCL = chemotactic cytokine ligand; Eo = Eosinophils; IDEC = inflammatory dendritic epidermal cells;
IL = Interleukin; IFN = Interferon; KCs = Keratinocytes; LC = Langerhans cells; MC = Mast cells.
Some of the genes and gene products investigated in this thesis are highlighted in red.
With the recent development of new technologies, such as whole-genome association studies and microarrays, we should now be able to expand on our knowledge in eczema pathogenesis. Correlating whole-genome expression data with whole-genome SNP association studies in the same study materials should assist in the identification of both new candidate genes and contributory disease pathways. Ultimately, an improved understanding of the genetic basis of eczema is likely to assist with a better subdivision of this complex disease and will hopefully lead to the development of novel effective
6 ACKNOWLEDGEMENTS
I wish to express my sincere gratitude to everyone that has contributed to this thesis and especially acknowledge and extend my thanks to the following:
All the eczema patients, their families and the healthy controls in our studies.
My main supervisor Mauro D’Amato, and my co-supervisors Susanne Gabrielsson, Maria Bradley and Magnus Nordenskjöld. Thanks for all your patience and for providing excellent tutoring and advice in a number of different subjects. Special thanks to Maria and Magnus for welcoming me to their lab and providing such a positive work environment. In the context of tutoring, I would also like to thank Ingrid Kockum for answering an infinite number of questions related to genetic association studies.
To all the co-authors on the papers in the thesis.
To former co-workers at MTC, Annelie, Anki, Annika, Britta, Check-Mei, Emelie, Fransesca, Gedas, Gesan, Ing-Marie, Kerstin, Linda, Lisa, Sascha, Sebastian, Stephen and Ylva…You better hurry up…
To all my friends and colleagues at the department of Medicine with special thanks to Annika Scheynius, Maria Tengvall-Linder, Carl-Fredrik Wahlgren and Eva Buentke.
To my friends at CFGR, Johanna, Frida, Halil…
To all friends and colleagues from the Centre for Allergy Research. Special thanks to my mentor Bengt Björkstén, Sven-Erik Dahlén and Anne Renström.
To all my current coworkers and collaborators at CMM, with special thanks to Elisabeth and Annika, Sigrid, Jenny, Fabio, Mona, Anna-Lena, Lina, Anna, Eva, Fredrik, Josephine, Johanna, Keng-Ling...
To my collaborators in Singapore with special thanks to I-Chun Kuo and Kaw Yan Chua.
To my family for all your patience and support.
Finally, and most importantly. To Lotta, my true companion. I wouldn’t have made it without you as my supporter. Thanks for being my “bollplank” in things big, small, crazy and stupid and thanks for picking me up when I’ve been down. I love you more than I can say…
7 REFERENCES
1. Strachan T, Read AP, Human Molecular Genetics (3rd edition), 2003.
2. Lander ES, Initial sequencing and analysis of the human genome. Nature 2001;409: 860-921.
3. Venter JC, The sequence of the human genome. Science (New York, NY 2001;291: 1304-1351.
4. Finishing the euchromatic sequence of the human genome. Nature 2004;431:
931-945.
5. Haines J, Pericak-Vance M, Genetic Analysis of Complex Disease (2nd edition), 2006.
6. Chakravarti A, Population genetics--making sense out of sequence. Nat Genet 1999;21: 56-60.
7. Lander ES, The new genomics: global views of biology. Science (New York, NY 1996;274: 536-539.
8. Pritchard JK, Are rare variants responsible for susceptibility to complex diseases? Am J Hum Genet 2001;69: 124-137.
9. Wall JD, Pritchard JK, Haplotype blocks and linkage disequilibrium in the human genome. Nat Rev Genet 2003;4: 587-597.
10. Janeway C, Travers P, Walport M, et al., Immunobiology, The Immune System in Health and Disease (6th edition), 2004.
11. Boman HG, Innate immunity and the normal microflora. Immunological reviews 2000;173: 5-16.
12. Zasloff M, Antimicrobial peptides in health and disease. The New England journal of medicine 2002;347: 1199-1200.
13. Steinman RM, The control of immunity and tolerance by dendritic cell.
Pathologie-biologie 2003;51: 59-60.
14. Banchereau J, Steinman RM, Dendritic cells and the control of immunity.
Nature 1998;392: 245-252.
15. Schuurhuis DH, Fu N, Ossendorp F, et al., Ins and outs of dendritic cells.
International archives of allergy and immunology 2006;140: 53-72.
16. Iwasaki A, Medzhitov R, Toll-like receptor control of the adaptive immune responses. Nature immunology 2004;5: 987-995.
17. Shortman K, Naik SH, Steady-state and inflammatory dendritic-cell development. Nature reviews 2007;7: 19-30.
18. O'Doherty U, Peng M, Gezelter S, et al., Human blood contains two subsets of dendritic cells, one immunologically mature and the other immature.
Immunology 1994;82: 487-493.
19. Robinson SP, Patterson S, English N, et al., Human peripheral blood contains two distinct lineages of dendritic cells. European journal of immunology 1999;29: 2769-2778.
20. Valladeau J, Ravel O, Dezutter-Dambuyant C, et al., Langerin, a novel C-type lectin specific to Langerhans cells, is an endocytic receptor that induces the formation of Birbeck granules. Immunity 2000;12: 71-81.
21. Wilson NS, Villadangos JA, Regulation of antigen presentation and cross-presentation in the dendritic cell network: facts, hypothesis, and immunological implications. Advances in immunology 2005;86: 241-305.
22. Romani N, Ebner S, Tripp CH, et al., Epidermal Langerhans cells--changing views on their function in vivo. Immunology letters 2006;106: 119-125.
23. Ueno H, Klechevsky E, Morita R, et al., Dendritic cell subsets in health and disease. Immunological reviews 2007;219: 118-142.
24. Wollenberg A, Kraft S, Hanau D, et al., Immunomorphological and
ultrastructural characterization of Langerhans cells and a novel, inflammatory dendritic epidermal cell (IDEC) population in lesional skin of atopic eczema. J Invest Dermatol 1996;106: 446-453.
26. Sallusto F, Lanzavecchia A, Efficient presentation of soluble antigen by cultured human dendritic cells is maintained by granulocyte/macrophage colony-stimulating factor plus interleukin 4 and downregulated by tumor necrosis factor alpha. The Journal of experimental medicine 1994;179: 1109-1118.
27. Kalinin AE, Kajava AV, Steinert PM, Epithelial barrier function: assembly and structural features of the cornified cell envelope. Bioessays 2002;24: 789-800.
28. Madison KC, Barrier function of the skin: "la raison d'etre" of the epidermis. J Invest Dermatol 2003;121: 231-241.
29. Candi E, Schmidt R, Melino G, The cornified envelope: a model of cell death in the skin. Nat Rev Mol Cell Biol 2005;6: 328-340.
30. Lorand L, Graham RM, Transglutaminases: crosslinking enzymes with pleiotropic functions. Nat Rev Mol Cell Biol 2003;4: 140-156.
31. DiGiovanna JJ, Bale SJ, Clinical heterogeneity in epidermolytic hyperkeratosis.
Archives of dermatology 1994;130: 1026-1035.
32. Huber M, Rettler I, Bernasconi K, et al., Mutations of keratinocyte
transglutaminase in lamellar ichthyosis. Science (New York, NY 1995;267:
525-528.
33. Russell LJ, DiGiovanna JJ, Rogers GR, et al., Mutations in the gene for transglutaminase 1 in autosomal recessive lamellar ichthyosis. Nat Genet 1995;9: 279-283.
34. Cork MJ, Robinson DA, Vasilopoulos Y, et al., New perspectives on epidermal barrier dysfunction in atopic dermatitis: Gene-environment interactions. Journal of Allergy and Clinical Immunology 2006;118: 3-21.
35. Schreiber S, Rosenstiel P, Albrecht M, et al., Genetics of Crohn disease, an archetypal inflammatory barrier disease. Nat Rev Genet 2005;6: 376-388.
36. Janeway C TP, Walport M and Shlomchik M., Immunobiology, The Immune System in Health and Disease. 6th Edn: Garland Science, 2004.
37. Johansson SG, Bieber T, Dahl R, et al., Revised nomenclature for allergy for global use: Report of the Nomenclature Review Committee of the World Allergy Organization, October 2003. J Allergy Clin Immunol 2004;113: 832-836.
38. Asher MI, Montefort S, Bjorksten B, et al., Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys. Lancet 2006;368: 733-743.
39. Strachan DP, Hay fever, hygiene, and household size. BMJ (Clinical research ed 1989;299: 1259-1260.
40. Romagnani S, The increased prevalence of allergy and the hygiene hypothesis:
missing immune deviation, reduced immune suppression, or both? Immunology 2004;112: 352-363.
41. Williams H, Flohr C, How epidemiology has challenged 3 prevailing concepts about atopic dermatitis. J Allergy Clin Immunol 2006;118: 209-213.
42. Leung DY, Bieber T, Atopic dermatitis. Lancet 2003;361: 151-160.
43. Morar N, Willis-Owen SAG, Moffatt MF, et al., The genetics of atopic dermatitis. Journal of Allergy and Clinical Immunology 2006;118: 24-34.
44. Ring J, Przybilla B, Ruzicka T, Handbook of Atopic Eczema (2nd edition), 2006.
45. Beattie PE, Lewis-Jones MS, A comparative study of impairment of quality of life in children with skin disease and children with other chronic childhood diseases. Br J Dermatol 2006;155: 145-151.
46. Lewis-Jones S, Quality of life and childhood atopic dermatitis: the misery of living with childhood eczema. International journal of clinical practice 2006;60:
984-992.
47. Spergel JM, Paller AS, Atopic dermatitis and the atopic march. J Allergy Clin Immunol 2003;112: S118-127.
48. Illi S, von Mutius E, Lau S, et al., The natural course of atopic dermatitis from
49. Flohr C, Johansson SG, Wahlgren CF, et al., How atopic is atopic dermatitis? J Allergy Clin Immunol 2004;114: 150-158.
50. Ring J, Darsow U, Behrendt H, Role of aeroallergens in atopic eczema: proof of concept with the atopy patch test. Journal of the American Academy of
Dermatology 2001;45: S49-52.
51. Akdis CA, Akdis M, Bieber T, et al., Diagnosis and treatment of atopic dermatitis in children and adults: European Academy of Allergology and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL Consensus Report. J Allergy Clin Immunol 2006;118: 152-169.
52. Uehara M, Kimura C, Descendant family history of atopic dermatitis. Acta Derm Venereol 1993;73: 62-63.
53. Larsen FS, Holm NV, Henningsen K, Atopic dermatitis. A genetic-epidemiologic study in a population-based twin sample. Journal of the American Academy of Dermatology 1986;15: 487-494.
54. Schultz Larsen F, Atopic dermatitis: a genetic-epidemiologic study in a population-based twin sample. Journal of the American Academy of Dermatology 1993;28: 719-723.
55. Beyer K, Nickel R, Freidhoff L, et al., Association and linkage of atopic dermatitis with chromosome 13q12-14 and 5q31-33 markers. J Invest Dermatol 2000;115: 906-908.
56. Bradley M, Soderhall C, Luthman H, et al., Susceptibility loci for atopic dermatitis on chromosomes 3, 13, 15, 17 and 18 in a Swedish population.
Human molecular genetics 2002;11: 1539-1548.
57. Cookson WOCM, Ubhi B, Lawrence R, et al., Genetic linkage of childhood atopic dermatitis to psoriasis susceptibility loci. 2001;27: 372-373.
58. Haagerup A, Bjerke T, Schiotz PO, et al., Atopic dermatitis -- a total genome-scan for susceptibility genes. Acta Derm Venereol 2004;84: 346-352.
59. Lee YA, Wahn U, Kehrt R, et al., A major susceptibility locus for atopic dermatitis maps to chromosome 3q21. Nat Genet 2000;26: 470-473.
60. Soderhall C, Bradley M, Kockum I, et al., Linkage and association to candidate regions in Swedish atopic dermatitis families. Human genetics 2001;109: 129-135.
61. Hata M, Tokura Y, Takigawa M, et al., Assessment of epidermal barrier function by photoacoustic spectrometry in relation to its importance in the pathogenesis of atopic dermatitis. Lab Invest 2002;82: 1451-1461.
62. Jakasa I, de Jongh CM, Verberk MM, et al., Percutaneous penetration of sodium lauryl sulphate is increased in uninvolved skin of patients with atopic dermatitis compared with control subjects. Br J Dermatol 2006;155: 104-109.
63. Jakasa I, Verberk MM, Esposito M, et al., Altered penetration of polyethylene glycols into uninvolved skin of atopic dermatitis patients. J Invest Dermatol 2007;127: 129-134.
64. Ogawa H, Yoshiike T, Atopic dermatitis: studies of skin permeability and effectiveness of topical PUVA treatment. Pediatr Dermatol 1992;9: 383-385.
65. Werner Y, Lindberg M, Transepidermal water loss in dry and clinically normal skin in patients with atopic dermatitis. Acta Derm Venereol 1985;65: 102-105.
66. Palmer CN, Irvine AD, Terron-Kwiatkowski A, et al., Common loss-of-function variants of the epidermal barrier protein filaggrin are a major predisposing factor for atopic dermatitis. Nat Genet 2006;38: 441-446.
67. Walley AJ, Chavanas S, Moffatt MF, et al., Gene polymorphism in Netherton and common atopic disease. Nat Genet 2001;29: 175-178.
68. Vasilopoulos Y, Cork MJ, Murphy R, et al., Genetic association between an AACC insertion in the 3'UTR of the stratum corneum chymotryptic enzyme gene and atopic dermatitis. J Invest Dermatol 2004;123: 62-66.
69. Vasilopoulos Y, Cork MJ, Teare D, et al., A nonsynonymous substitution of cystatin A, a cysteine protease inhibitor of house dust mite protease, leads to decreased mRNA stability and shows a significant association with atopic
70. Soderhall C, Marenholz I, Kerscher T, et al., Variants in a novel epidermal collagen gene (COL29A1) are associated with atopic dermatitis. PLoS biology 2007;5: e242.
71. Ahmad-Nejad P, Mrabet-Dahbi S, Breuer K, et al., The toll-like receptor 2 R753Q polymorphism defines a subgroup of patients with atopic dermatitis having severe phenotype. J Allergy Clin Immunol 2004;113: 565-567.
72. Jones G, Wu S, Jang N, et al., Polymorphisms within the CTLA4 gene are associated with infant atopic dermatitis. Br J Dermatol 2006;154: 467-471.
73. Kawashima T, Noguchi E, Arinami T, et al., Linkage and association of an interleukin 4 gene polymorphism with atopic dermatitis in Japanese families.
Journal of medical genetics 1998;35: 502-504.
74. Oiso N, Fukai K, Ishii M, Interleukin 4 receptor alpha chain polymorphism Gln551Arg is associated with adult atopic dermatitis in Japan. Br J Dermatol 2000;142: 1003-1006.
75. Novak N, Kruse S, Potreck J, et al., Single nucleotide polymorphisms of the IL18 gene are associated with atopic eczema. J Allergy Clin Immunol 2005;115: 828-833.
76. Nishio Y, Noguchi E, Ito S, et al., Mutation and association analysis of the interferon regulatory factor 2 gene (IRF2) with atopic dermatitis. Journal of human genetics 2001;46: 664-667.
77. Lange J, Heinzmann A, Zehle C, et al., CT genotype of promotor
polymorphism C159T in the CD14 gene is associated with lower prevalence of atopic dermatitis and lower IL-13 production. Pediatr Allergy Immunol 2005;16: 456-457.
78. Rafatpanah H, Bennett E, Pravica V, et al., Association between novel GM-CSF gene polymorphisms and the frequency and severity of atopic dermatitis. J Allergy Clin Immunol 2003;112: 593-598.
79. Weidinger S, Klopp N, Rummler L, et al., Association of NOD1
polymorphisms with atopic eczema and related phenotypes. J Allergy Clin Immunol 2005;116: 177-184.
80. Cox HE, Moffatt MF, Faux JA, et al., Association of atopic dermatitis to the beta subunit of the high affinity immunoglobulin E receptor. Br J Dermatol 1998;138: 182-187.
81. Chae SC, Song JH, Lee YC, et al., The association of the exon 4 variations of Tim-1 gene with allergic diseases in a Korean population. Biochemical and biophysical research communications 2003;312: 346-350.
82. Jang N, Stewart G, Jones G, Polymorphisms within the PHF11 gene at chromosome 13q14 are associated with childhood atopic dermatitis. Genes Immun 2005;6: 262-264.
83. Mao XQ, Shirakawa T, Yoshikawa T, et al., Association between genetic variants of mast-cell chymase and eczema. Lancet 1996;348: 581-583.
84. Ekelund E, Saaf A, Tengvall-Linder M, et al., Elevated expression and genetic association links the SOCS3 gene to atopic dermatitis. Am J Hum Genet 2006;78: 1060-1065.
85. Arkwright PD, Chase JM, Babbage S, et al., Atopic dermatitis is associated with a low-producer transforming growth factor beta(1) cytokine genotype. J Allergy Clin Immunol 2001;108: 281-284.
86. Dale BA, Resing KA, Lonsdale-Eccles JD, Filaggrin: a keratin filament associated protein. Ann N Y Acad Sci 1985;455: 330-342.
87. Gan SQ, McBride OW, Idler WW, et al., Organization, structure, and polymorphisms of the human profilaggrin gene. Biochemistry 1990;29: 9432-9440.
88. Steinert PM, Cantieri JS, Teller DC, et al., Characterization of a class of cationic proteins that specifically interact with intermediate filaments. Proc Natl Acad Sci U S A 1981;78: 4097-4101.
89. Smith FJ, Irvine AD, Terron-Kwiatkowski A, et al., Loss-of-function mutations in the gene encoding filaggrin cause ichthyosis vulgaris. Nat Genet 2006;38:
91. Sandilands A, Terron-Kwiatkowski A, Hull PR, et al., Comprehensive analysis of the gene encoding filaggrin uncovers prevalent and rare mutations in ichthyosis vulgaris and atopic eczema. Nat Genet 2007.
92. Sugiura H, Ebise H, Tazawa T, et al., Large-scale DNA microarray analysis of atopic skin lesions shows overexpression of an epidermal differentiation gene cluster in the alternative pathway and lack of protective gene expression in the cornified envelope. Br J Dermatol 2005;152: 146-149.
93. Morar N, Cookson WO, Harper JI, et al., Filaggrin Mutations in Children with Severe Atopic Dermatitis. J Invest Dermatol 2007.
94. Novak N, Bieber T, Leung DY, Immune mechanisms leading to atopic dermatitis. J Allergy Clin Immunol 2003;112: S128-139.
95. Kondo H, Ichikawa Y, Imokawa G, Percutaneous sensitization with allergens through barrier-disrupted skin elicits a Th2-dominant cytokine response.
European journal of immunology 1998;28: 769-779.
96. Matsui K, Nishikawa A, Lipoteichoic acid from Staphylococcus aureus induces Th2-prone dermatitis in mice sensitized percutaneously with an allergen. Clin Exp Allergy 2002;32: 783-788.
97. Hamid Q, Boguniewicz M, Leung DY, Differential in situ cytokine gene expression in acute versus chronic atopic dermatitis. J Clin Invest 1994;94: 870-876.
98. Bieber T, de la Salle H, Wollenberg A, et al., Human epidermal Langerhans cells express the high affinity receptor for immunoglobulin E (Fc epsilon RI).
The Journal of experimental medicine 1992;175: 1285-1290.
99. Novak N, Bieber T, The role of dendritic cell subtypes in the pathophysiology of atopic dermatitis. Journal of the American Academy of Dermatology 2005;53: S171-176.
100. Geiger E, Magerstaedt R, Wessendorf JH, et al., IL-4 induces the intracellular expression of the alpha chain of the high-affinity receptor for IgE in in vitro-generated dendritic cells. J Allergy Clin Immunol 2000;105: 150-156.
101. Panhans-Gross A, Novak N, Kraft S, et al., Human epidermal Langerhans' cells are targets for the immunosuppressive macrolide tacrolimus (FK506). J Allergy Clin Immunol 2001;107: 345-352.
102. Novak N, Valenta R, Bohle B, et al., FcepsilonRI engagement of Langerhans cell-like dendritic cells and inflammatory dendritic epidermal cell-like dendritic cells induces chemotactic signals and different T-cell phenotypes in vitro. J Allergy Clin Immunol 2004;113: 949-957.
103. Maintz L, Novak N, Getting more and more complex: the pathophysiology of atopic eczema. Eur J Dermatol 2007;17: 267-283.
104. Buentke E, Zargari A, Heffler LC, et al., Uptake of the yeast Malassezia furfur and its allergenic components by human immature CD1a+ dendritic cells. Clin Exp Allergy 2000;30: 1759-1770.
105. Buentke E, Heffler LC, Wallin RP, et al., The allergenic yeast Malassezia furfur induces maturation of human dendritic cells. Clin Exp Allergy 2001;31: 1583-1593.
106. Huang CH, Kuo IC, Xu H, et al., Mite allergen induces allergic dermatitis with concomitant neurogenic inflammation in mouse. J Invest Dermatol 2003;121:
289-293.
107. Heymann PW, Chapman MD, Aalberse RC, et al., Antigenic and structural analysis of group II allergens (Der f II and Der p II) from house dust mites (Dermatophagoides spp). J Allergy Clin Immunol 1989;83: 1055-1067.
108. Sporik R, Chapman MD, Platts-Mills TA, House dust mite exposure as a cause of asthma. Clin Exp Allergy 1992;22: 897-906.
109. von Stein OD, Isolation of differentially expressed genes through subtractive suppression hybridization. Methods Mol Biol 2001;175: 263-278.
110. Bradley M, Kockum I, Soderhall C, et al., Characterization by phenotype of families with atopic dermatitis. Acta Derm Venereol 2000;80: 106-110.
111. Williams HC, Burney PG, Hay RJ, et al., The U.K. Working Party's Diagnostic