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Autoreactive CD4+ T-cell responses to the extracellular domain (ECD) of bullous pemphigoid antigen 2 (BPAG2) in BP patients
ESDR I JSID I SID Abstracts
S28
0166
0163 AUTORFACTNE
CD4+ T-CELL RESPONSES TO TEE EXTRACELLULAR
DOMAIN (ECD) OF BULLOUS PEMPHIGOID ANTIGEN 2 (BPAGZ) IN BP PATIENTS. L. Biidinee?. L. Borradori*‘. C. Yee*. H.F. Merk”. K B. Yancev*. M.
&&, “Hautklinik der RWTH Aachen, Germany; ‘Clinique de Dennatologie, Hopital Cantonaluniversitaire Geneve, Switzerland;‘Dennatology Branch, NCI, Bethesda, USA. The patbogenesis of BP is presumably mediated by auto-antibodies (Ab) against hemidesmosomal adhesion molecules. Similarly to panphigus vulgaris (PV), BP is characterized by the prevalence of a particular MHC II allele @QRI*0301) suggesting that immunogenetic factors are critically involved in the etiopathogenesis. Based on our findings with autoreactive T cells in PV, the aim of this study was to identify T cell responses to BPAGZ, the major candidate autoantigen of BP, which may serve as targets for the modulation of the production of pathogenic auto-Ab. PBMC from 9 DRll**/DQl31*0301+ BP patients showed a significant primary response to the recombinant
protein BV13
which represents the major pation
(aa 485-1430)
of the
ECD of BPAGZ (S1=3-50, background: 344-6488 cpm). Nine CD4+ T-cell lines and 22 T-cell clones generated from 6 BP patients showed a significant proliferative response to BV13 (SI=3-28, background: 246-2124 cpm) In addition, 2 T cell lines and 7 T-cell clones from 2 BP patients were also stimulated by a recombinant protein consisting of the outer 2/3 (aa 804-1430) of the ECD of BPAGZ (SI=3-8, background: 751-2114 cpm). Interestingly, the proliferative response to BPAG2 of a CD4+ T cell line was restricted by DQ01*0301, the major suceptibility allele ofBP. The majority (l8/22) of
EVIDENCETHATBPAGZINTERACTSWITH a6 INTEGRTN:PERTURBATIONOF THIS ASSOCL4TlON INBIBITS HEMIDESMOSOMEASSEMBLY. Susan B. Hopkinson,Kirk Findlay and JonathanC.R. Jones, l%partment of Cell and Molecular Bmloev. -. NorthwesternUnivmltv MedicalSchool.Chlcazo.USA. The hemidesmosomets a n&molecular complex which integrates the extracellular matrix wlfh the keratin cytoskeleton and which stahdizes epithelial attachment to connectivetissue. BPAGZISa transmembrane component of the hemldesmosome with a collagen-like ex!xacellular domam. Here, usmg the yeast two-hybrid system as well as recombinantly expressed molecules m blot overlay and co-immunopreclpltahon assays, we have identified a6 integrin as a BPAGZ binding parmer. The association hehveen BPAGZ and a6 integrm is inhibited hy a 14 ma peptide whose sequence is idenhcal to ammo acld residues 506-519 m the non-collagenous region of thee&domain (NCE) of the type XVII collagen molecule.This same sequenceis part of the epatoperecognzed
bv autcantibcd~eswhich are wthwenic m bullous pemphiwid. In viva, when 804G cells are plated Into medium containing the same bhde, they fad to assemble mature hemidesmosomes. Furthermore, although BPAGZ and catam cytoplasnuc components
of the hemldesmosomecwlocahze m the peptIde tieated cells, they are aberantly dxtnhuted and fail to show extenwe asxxlahon witha6P4 integnn. Taken together, our results mdxate that BPAGZ is a novel hxnsmembrane bgand of the a6P4 integrm heterodimer. In additmn, interactmn between BPAGZ and a6 mtegnn IS not only medlated by the bullous pemphlgoid epttope hut is necessary for hemidesmosome formation.
BPAG2-specific T-cell clones from two BP patients secreted TH2 cytokines (IL-5 but no II?+), while 4122 T-cell clones produced IL-5 and EN-y These observations thus contim~ the presence of CD4+, mainly TH2-like autoreactive T cells in patients with BP which recognize distinct epitopes of the ECD ofBPAG2.
0164
0167
SIGNALING IS A KEY COMPONENTOF ULTRAVIOLETA RADIATION (lJVAR)-INDUCEDGENE EXPRESSIONIN HUMAN KERATINOCYIES(KC). &a~&$ Grether-Beck.Heldi Schmitt. Ineo Felsner. Giusamina Ban”+ lzzl .&@ea Piette’. Judith e _ lohnson’. Dept. of Dermatologyand “Inst. of physiol. Chem. I, Univ. of Diisseldorf, Diisseldorf, Germany; ‘Inst. Immunol., LMU, Munich, Germany;+Lab.of Med. Chem., Univ. of Liege, Belgium. expression of genes in human KC. We have previously demonstratedthat the pathway by which UVARinducestranscriptionalactivationof humangenes includingintercellularadhesion moleculkl (ICAM-1)differs from &at inducedby UVBR and that it specificallyinvolvea the activation of transcriptionfxtor AP-2. We ww report fhat ceramidesare part of this signal aansdwtion pathway.By employinggeI&ctmphorefic-mobilityshift assayswe have observed that treatmeat of KC with ceramidesincreasedDNA-bindingactivity of transcription factor AP-2. In order to assess the functionalrelevance of cerandde-inducedAP-2 activation, KC were transientlytransfectedwith a series of ICAM- basedluciferasereportergene constructs. Constructs with ICAM-I fragments up to 6CCO/+1 displayed significant responsivenessto stimulation with UVA radiation or ceramides. For both stimuli, responsiveness was completelyabolished, if a constru~flacking the AP-2 site was used, indicating a cause-effect relationship. Accordingly, exposure to UVAR significantly@fold) increasedthe formationof cemmides in human KC. Moreover, UVAR-inducedICAM- mRNA expression could be completely prevented when ceramide synthesis was inhibited in KC with cycloserine or fumonisin 8. These effects were speeitic, becauseaddition of ceramidesto inhibitor-treated KC post irradiation mIored ICAM-I expression,and becausethese inhibitors did not prevent cytoklle (TNFa,IFN-y)-inducedKC ICAM-I expression. Ceramidesthus play a previously unrecognizedrole in AP-2 activation and UVA radiation-inducedgene expression.
ACIIVATION OF SKIN-DERIVED DENDRITIC CELLS BY CpG-CONTAINING OLICODEOXYNIJCLBO’ITDES(ODN) WITH IMMUNOSTIMULATORY ACTIVITY. I P. S Walker*.T. and J. V@ Dermatology Branch, NCI, Bethesda, MD and #Dqxuanent of Medicine, University of Iowa, Iowa City, IA. Genetic vaccination involves the intmduction of bacterial plasmids encoding antigens of interest directly into naive recipients. The efficacy of this appmach in preventing diseases such as leishmaniasis depends, in pat, on the ability of genetic vaccines to induce Thl predominant immune responses. It has been suggested that this immunomodulatoly activity of plasmid-based vaccines is attributable to umnethylated CpC sequences in bacterial DNA. Indeed, CpG-containing ODN [Immunostimulatory (I.%-ODN)] exhibit adjuvam pmperdes like those of bacterial plasmids. Because dendritic cells (DC) are thought to participate in T cell priming during DNA vaccination (including DNA vaccination via skin), we characterizedthe effects of ODN on skin-derived DC. Like the LX! activators IL-l, ‘INPa and LPS, adding ISS ODN 1826 (6 &ml) to Langemans cell-like immature mwine fetal skin-derived dend&ic cells (FSDDC) resulted in acquisition of a more mature phenotype (with increased expression of MHC antigens, CD@. CD80 and CD86) over 12-18 h ‘Ihe same conceneation of a compositionmatched ODN lacking CpG sequences (ODN I91 1) was without effect ISS ODN 1826 also selectively augmented the ability of FSDDC to stimulate allogeneic T cells and to produce cytokines (including IL-12). Analysis of FSDDC cytokine production by ELISA revealed that ISS ODN 1826 stimulated release of large amounts of IL12 p40 (16.Q2.9 ng/5x10’/18 h versus 1.3fl.6 ng/5x10%8 h for ODN 1911 and l.tiO.5 ng/5xld/l8 h for LPS). Flow cytometry stmlii also indicated that injection of ISS ODN 1826 (50 pg) into murine skin selectively augmented I-A and CD86 expression by a subpopulation (-2096, ~2) of LC within 12 h. We conclude that CpC sequences activate cutaneous DC in viva as well as in vitro, induce IL12 production by DC and may facilitate Thl cytokine production during genetic vaccination by modulating DC function. *Denotes authors that made equal contributions to fbii study.
0165
0168
IDENTIFICATION OF IP-9, A NOVEL CXC-CHEMOKINE EXPRESSED BY KERATINOCYTES C.P. ‘da Samoat_SardioeDmad * w* and R w Depts of Demmtology’, Pathologyt. Molecular Neumbiologyp and Pharmacology”, Vrije Unlversiteit, Amsterdam The Netherlands. In a search for human chemokines expressed by keratinocytes, we challenged CHO cells expressing cDNAs encoding chemokine receptors with patially purified proteins obtained from stimulated cultured ketainocytes. By measuring effects on intracellular second messenger systems (Ca” mobilization) we were able to identify several bioactive proteins. Puriftcation and determination of the N-terminal amino acid sequence of one these prcteins, revealed a novel chemokine, which was designated II’-9 @N-y-inducible Protein-9). Molecular cloning of a cDNA enccding the Ip-9 precursor protein, revealed that IF’-9 is a CXC chemokine most closely related to the CXC chemokines IF’-10 and MIG. Elucidation of the intmnlexon organization of the codiig region of the IF9 gene by sequence analysis demonstrated a high similarity with the IF’-10 gene and confirmed the cDNA sequencing data. Northern blot analysis demonstrated that IF’-9 mRNA expression by y-IFN stimulated cultured keratinocytes is time and dose dependent. Finally, we were able to detect IF’-9 mRNA expression in keratinocytes in skin biopsies of delayed type hypersensitivity reactions using in situ hybridization, strongly suggesting a functional role for this novel chemokine in skin inflammation.
MOLECULAR BASIS OF ALOPECIA UNIVERSA LIS: POSITIONAL-CANDIDATE GENE AND IDENTIFICATION OF A CLONING OF THE Hl JMAN ha/&w MUTATION. A. M. Chrisflano, M.F. ul Haque. V. Brancolinl, S. ul Haque, H. Lam, V. Aita, J. Frank, P. 6. Cseihalml-brIe&an, A. Leask J. A f&Lath, M Ahmad, J CSfi and W. Ahmad. D t f De tol d G b Columbm tJnl;erslly NY’ D ftl lology,e?&&-zi U%%ty e&?&ad Pakistan’ Lab&to& foi S%i&l Genetics, The Rcd(efeller U&sky, NY, ‘NY. Fib&m Inc. San Francisco, CA; St. John’s Institute of Dermatology, St. Thorn.&’ Hospital, l&d&, UK. There are several forms of hereditary human hair loss. known cullectlvely as alopecias. which may represent a dysregulation of the hair cycle, yet the mdewlar basis of the alopecias is entire1 unknown. We ascertained a kindred with recessively inherited alopecia univelsalis K U), inlbatsd ” a search for rnkage using homozygosity mappin and established linkage to a 6 CM interval on chmmcwne 12 between the ma R ers DSS258 and DBS1739, with a LOD score of 6.19. In an .? I” ependent line of investigation, win radiation hybn‘d mapping, we placed the human hom&g of the mutinehairfes.s gene en a 19 CM interval cm 8~21 between tie markers DSS280 and D8S278, which also contained the 6 CM linkage interval. Based on this genomic cclocalization, hairfess became a major candidate gene responsible for AU in this family. We cloned the human hairless gene, and mutaf~on anal is revealed a homozy ous A-to-G transition in exon 15 in all affected individuals.
CERAMIDE
In order to understand the impact of solar radiation on human skin it is necessary to analyze the meclunisms by which physiologically relevant doses of UVBR and UVAR induce
m
t
(
TlemuIatknoaxlrredaQme
wescreened
142 mnf no evidence for the mutant allele in 2S4 chromosomes, 174 of which were ethnically matched for the AU family. The absence of the mutant allele in control individuals, together with the non-conservative nature of the amkm acid substitution. strongly suggests that this mutation in Ule human h&less gene underlies the AU phenotype in this family. We have identified the first ene implicated in an inherited fan of complete human hair loss, and anticipate that fu L r studies ‘. Into the biology of haidess and its transactivation targets may illuminate potential therapeutic opportunities in the future.
S28
0166
0163 AUTORFACTNE
CD4+ T-CELL RESPONSES TO TEE EXTRACELLULAR
DOMAIN (ECD) OF BULLOUS PEMPHIGOID ANTIGEN 2 (BPAGZ) IN BP PATIENTS. L. Biidinee?. L. Borradori*‘. C. Yee*. H.F. Merk”. K B. Yancev*. M.
&&, “Hautklinik der RWTH Aachen, Germany; ‘Clinique de Dennatologie, Hopital Cantonaluniversitaire Geneve, Switzerland;‘Dennatology Branch, NCI, Bethesda, USA. The patbogenesis of BP is presumably mediated by auto-antibodies (Ab) against hemidesmosomal adhesion molecules. Similarly to panphigus vulgaris (PV), BP is characterized by the prevalence of a particular MHC II allele @QRI*0301) suggesting that immunogenetic factors are critically involved in the etiopathogenesis. Based on our findings with autoreactive T cells in PV, the aim of this study was to identify T cell responses to BPAGZ, the major candidate autoantigen of BP, which may serve as targets for the modulation of the production of pathogenic auto-Ab. PBMC from 9 DRll**/DQl31*0301+ BP patients showed a significant primary response to the recombinant
protein BV13
which represents the major pation
(aa 485-1430)
of the
ECD of BPAGZ (S1=3-50, background: 344-6488 cpm). Nine CD4+ T-cell lines and 22 T-cell clones generated from 6 BP patients showed a significant proliferative response to BV13 (SI=3-28, background: 246-2124 cpm) In addition, 2 T cell lines and 7 T-cell clones from 2 BP patients were also stimulated by a recombinant protein consisting of the outer 2/3 (aa 804-1430) of the ECD of BPAGZ (SI=3-8, background: 751-2114 cpm). Interestingly, the proliferative response to BPAG2 of a CD4+ T cell line was restricted by DQ01*0301, the major suceptibility allele ofBP. The majority (l8/22) of
EVIDENCETHATBPAGZINTERACTSWITH a6 INTEGRTN:PERTURBATIONOF THIS ASSOCL4TlON INBIBITS HEMIDESMOSOMEASSEMBLY. Susan B. Hopkinson,Kirk Findlay and JonathanC.R. Jones, l%partment of Cell and Molecular Bmloev. -. NorthwesternUnivmltv MedicalSchool.Chlcazo.USA. The hemidesmosomets a n&molecular complex which integrates the extracellular matrix wlfh the keratin cytoskeleton and which stahdizes epithelial attachment to connectivetissue. BPAGZISa transmembrane component of the hemldesmosome with a collagen-like ex!xacellular domam. Here, usmg the yeast two-hybrid system as well as recombinantly expressed molecules m blot overlay and co-immunopreclpltahon assays, we have identified a6 integrin as a BPAGZ binding parmer. The association hehveen BPAGZ and a6 integrm is inhibited hy a 14 ma peptide whose sequence is idenhcal to ammo acld residues 506-519 m the non-collagenous region of thee&domain (NCE) of the type XVII collagen molecule.This same sequenceis part of the epatoperecognzed
bv autcantibcd~eswhich are wthwenic m bullous pemphiwid. In viva, when 804G cells are plated Into medium containing the same bhde, they fad to assemble mature hemidesmosomes. Furthermore, although BPAGZ and catam cytoplasnuc components
of the hemldesmosomecwlocahze m the peptIde tieated cells, they are aberantly dxtnhuted and fail to show extenwe asxxlahon witha6P4 integnn. Taken together, our results mdxate that BPAGZ is a novel hxnsmembrane bgand of the a6P4 integrm heterodimer. In additmn, interactmn between BPAGZ and a6 mtegnn IS not only medlated by the bullous pemphlgoid epttope hut is necessary for hemidesmosome formation.
BPAG2-specific T-cell clones from two BP patients secreted TH2 cytokines (IL-5 but no II?+), while 4122 T-cell clones produced IL-5 and EN-y These observations thus contim~ the presence of CD4+, mainly TH2-like autoreactive T cells in patients with BP which recognize distinct epitopes of the ECD ofBPAG2.
0164
0167
SIGNALING IS A KEY COMPONENTOF ULTRAVIOLETA RADIATION (lJVAR)-INDUCEDGENE EXPRESSIONIN HUMAN KERATINOCYIES(KC). &a~&$ Grether-Beck.Heldi Schmitt. Ineo Felsner. Giusamina Ban”+ lzzl .&@ea Piette’. Judith e _ lohnson’. Dept. of Dermatologyand “Inst. of physiol. Chem. I, Univ. of Diisseldorf, Diisseldorf, Germany; ‘Inst. Immunol., LMU, Munich, Germany;+Lab.of Med. Chem., Univ. of Liege, Belgium. expression of genes in human KC. We have previously demonstratedthat the pathway by which UVARinducestranscriptionalactivationof humangenes includingintercellularadhesion moleculkl (ICAM-1)differs from &at inducedby UVBR and that it specificallyinvolvea the activation of transcriptionfxtor AP-2. We ww report fhat ceramidesare part of this signal aansdwtion pathway.By employinggeI&ctmphorefic-mobilityshift assayswe have observed that treatmeat of KC with ceramidesincreasedDNA-bindingactivity of transcription factor AP-2. In order to assess the functionalrelevance of cerandde-inducedAP-2 activation, KC were transientlytransfectedwith a series of ICAM- basedluciferasereportergene constructs. Constructs with ICAM-I fragments up to 6CCO/+1 displayed significant responsivenessto stimulation with UVA radiation or ceramides. For both stimuli, responsiveness was completelyabolished, if a constru~flacking the AP-2 site was used, indicating a cause-effect relationship. Accordingly, exposure to UVAR significantly@fold) increasedthe formationof cemmides in human KC. Moreover, UVAR-inducedICAM- mRNA expression could be completely prevented when ceramide synthesis was inhibited in KC with cycloserine or fumonisin 8. These effects were speeitic, becauseaddition of ceramidesto inhibitor-treated KC post irradiation mIored ICAM-I expression,and becausethese inhibitors did not prevent cytoklle (TNFa,IFN-y)-inducedKC ICAM-I expression. Ceramidesthus play a previously unrecognizedrole in AP-2 activation and UVA radiation-inducedgene expression.
ACIIVATION OF SKIN-DERIVED DENDRITIC CELLS BY CpG-CONTAINING OLICODEOXYNIJCLBO’ITDES(ODN) WITH IMMUNOSTIMULATORY ACTIVITY. I P. S Walker*.T. and J. V@ Dermatology Branch, NCI, Bethesda, MD and #Dqxuanent of Medicine, University of Iowa, Iowa City, IA. Genetic vaccination involves the intmduction of bacterial plasmids encoding antigens of interest directly into naive recipients. The efficacy of this appmach in preventing diseases such as leishmaniasis depends, in pat, on the ability of genetic vaccines to induce Thl predominant immune responses. It has been suggested that this immunomodulatoly activity of plasmid-based vaccines is attributable to umnethylated CpC sequences in bacterial DNA. Indeed, CpG-containing ODN [Immunostimulatory (I.%-ODN)] exhibit adjuvam pmperdes like those of bacterial plasmids. Because dendritic cells (DC) are thought to participate in T cell priming during DNA vaccination (including DNA vaccination via skin), we characterizedthe effects of ODN on skin-derived DC. Like the LX! activators IL-l, ‘INPa and LPS, adding ISS ODN 1826 (6 &ml) to Langemans cell-like immature mwine fetal skin-derived dend&ic cells (FSDDC) resulted in acquisition of a more mature phenotype (with increased expression of MHC antigens, CD@. CD80 and CD86) over 12-18 h ‘Ihe same conceneation of a compositionmatched ODN lacking CpG sequences (ODN I91 1) was without effect ISS ODN 1826 also selectively augmented the ability of FSDDC to stimulate allogeneic T cells and to produce cytokines (including IL-12). Analysis of FSDDC cytokine production by ELISA revealed that ISS ODN 1826 stimulated release of large amounts of IL12 p40 (16.Q2.9 ng/5x10’/18 h versus 1.3fl.6 ng/5x10%8 h for ODN 1911 and l.tiO.5 ng/5xld/l8 h for LPS). Flow cytometry stmlii also indicated that injection of ISS ODN 1826 (50 pg) into murine skin selectively augmented I-A and CD86 expression by a subpopulation (-2096, ~2) of LC within 12 h. We conclude that CpC sequences activate cutaneous DC in viva as well as in vitro, induce IL12 production by DC and may facilitate Thl cytokine production during genetic vaccination by modulating DC function. *Denotes authors that made equal contributions to fbii study.
0165
0168
IDENTIFICATION OF IP-9, A NOVEL CXC-CHEMOKINE EXPRESSED BY KERATINOCYTES C.P. ‘da Samoat_SardioeDmad * w* and R w Depts of Demmtology’, Pathologyt. Molecular Neumbiologyp and Pharmacology”, Vrije Unlversiteit, Amsterdam The Netherlands. In a search for human chemokines expressed by keratinocytes, we challenged CHO cells expressing cDNAs encoding chemokine receptors with patially purified proteins obtained from stimulated cultured ketainocytes. By measuring effects on intracellular second messenger systems (Ca” mobilization) we were able to identify several bioactive proteins. Puriftcation and determination of the N-terminal amino acid sequence of one these prcteins, revealed a novel chemokine, which was designated II’-9 @N-y-inducible Protein-9). Molecular cloning of a cDNA enccding the Ip-9 precursor protein, revealed that IF’-9 is a CXC chemokine most closely related to the CXC chemokines IF’-10 and MIG. Elucidation of the intmnlexon organization of the codiig region of the IF9 gene by sequence analysis demonstrated a high similarity with the IF’-10 gene and confirmed the cDNA sequencing data. Northern blot analysis demonstrated that IF’-9 mRNA expression by y-IFN stimulated cultured keratinocytes is time and dose dependent. Finally, we were able to detect IF’-9 mRNA expression in keratinocytes in skin biopsies of delayed type hypersensitivity reactions using in situ hybridization, strongly suggesting a functional role for this novel chemokine in skin inflammation.
MOLECULAR BASIS OF ALOPECIA UNIVERSA LIS: POSITIONAL-CANDIDATE GENE AND IDENTIFICATION OF A CLONING OF THE Hl JMAN ha/&w MUTATION. A. M. Chrisflano, M.F. ul Haque. V. Brancolinl, S. ul Haque, H. Lam, V. Aita, J. Frank, P. 6. Cseihalml-brIe&an, A. Leask J. A f&Lath, M Ahmad, J CSfi and W. Ahmad. D t f De tol d G b Columbm tJnl;erslly NY’ D ftl lology,e?&&-zi U%%ty e&?&ad Pakistan’ Lab&to& foi S%i&l Genetics, The Rcd(efeller U&sky, NY, ‘NY. Fib&m Inc. San Francisco, CA; St. John’s Institute of Dermatology, St. Thorn.&’ Hospital, l&d&, UK. There are several forms of hereditary human hair loss. known cullectlvely as alopecias. which may represent a dysregulation of the hair cycle, yet the mdewlar basis of the alopecias is entire1 unknown. We ascertained a kindred with recessively inherited alopecia univelsalis K U), inlbatsd ” a search for rnkage using homozygosity mappin and established linkage to a 6 CM interval on chmmcwne 12 between the ma R ers DSS258 and DBS1739, with a LOD score of 6.19. In an .? I” ependent line of investigation, win radiation hybn‘d mapping, we placed the human hom&g of the mutinehairfes.s gene en a 19 CM interval cm 8~21 between tie markers DSS280 and D8S278, which also contained the 6 CM linkage interval. Based on this genomic cclocalization, hairfess became a major candidate gene responsible for AU in this family. We cloned the human hairless gene, and mutaf~on anal is revealed a homozy ous A-to-G transition in exon 15 in all affected individuals.
CERAMIDE
In order to understand the impact of solar radiation on human skin it is necessary to analyze the meclunisms by which physiologically relevant doses of UVBR and UVAR induce
m
t
(
TlemuIatknoaxlrredaQme
wescreened
142 mnf no evidence for the mutant allele in 2S4 chromosomes, 174 of which were ethnically matched for the AU family. The absence of the mutant allele in control individuals, together with the non-conservative nature of the amkm acid substitution. strongly suggests that this mutation in Ule human h&less gene underlies the AU phenotype in this family. We have identified the first ene implicated in an inherited fan of complete human hair loss, and anticipate that fu L r studies ‘. Into the biology of haidess and its transactivation targets may illuminate potential therapeutic opportunities in the future.