Stratification of urinary bladder carcinoma based on immunohistochemical expression of CK5, CK14 and CK20.

Molecular subtyping of urothelial carcinoma (UC) is similar to that of breast cancer and is based on the developmental biology approach. The aim of the present study is to assess the prognostic impact of CK5, CK14, and CK20 expression in urinary bladder cancer (UBC) with the potential to stratify them into different subtypes. The current study examined the immunohistochemical expression of CK5, CK14, and CK20 in 90 specimens of UBC. CK5 was expressed in 81.1% of the cases and was significantly associated with old age, muscle invasion, presence of bilharziasis, and tendency for poor overall survival. CK20 was expressed in 47.8% of the cases and was associated with nonmuscle invasion and pure UC while 50% of the cases expressed CK14 that were associated with muscle invasion and perineural invasion. Most squamous cell carcinoma and those associated with bilharziasis were belonged to Ck5+/CK20- subgroup while pure UC and those lacked bilharziasis were located in the Ck5+/CK20+ subgroup. The basal group (Ck5+/CK14+/CK20-) showed high proliferative features compared to the intermediate group (Ck5+/CK14-/CK20-). Generally, presence of CK5 is associated with adverse features especially in the group lacking CK20; however, basal and intermediate subgroups share CK5 expression but they show different proliferative capacities, so their distinction by CK14 is helpful.

Murine HPV16 E7-expressing transgenic skin effectively emulates the cellular and molecular features of human high-grade squamous intraepithelial lesions.

Currently available vaccines prevent HPV infection and development of HPV-associated malignancies, but do not cure existing HPV infections and dysplastic lesions. Persistence of infection(s) in immunocompetent patients may reflect induction of local immunosuppressive mechanisms by HPV, providing a target for therapeutic intervention. We have proposed that a mouse, expressing HPV16 E7 oncoprotein under a Keratin 14 promoter (K14E7 mice), and which develops epithelial hyperplasia, may assist with understanding local immune suppression mechanisms that support persistence of HPV oncogene-induced epithelial hyperplasia. K14E7 skin grafts recruit immune cells from immunocompetent hosts, but consistently fail to be rejected. Here, we review the literature on HPV-associated local immunoregulation, and compare the findings with published observations on the K14E7 transgenic murine model, including comparison of the transcriptome of human HPV-infected pre-malignancies with that of murine K14E7 transgenic skin. We argue from the similarity of i) the literature findings and ii) the transcriptome profiles that murine K14E7 transgenic skin recapitulates the cellular and secreted protein profiles of high-grade HPV-associated lesions in human subjects. We propose that the K14E7 mouse may be an appropriate model to further study the immunoregulatory effects of HPV E7 expression, and can facilitate development and testing of therapeutic vaccines.

Expression of IL-33 in ocular surface epithelium induces atopic keratoconjunctivitis with activation of group 2 innate lymphoid cells in mice.

In a transgenic mouse line hK14mIL33tg, with the expression of interleukin-33 (IL-33) driven by a keratin 14 promoter, keratoconjunctivitis developed spontaneously between 18 and 22 weeks of age under specific-pathogen-free conditions. These mice showed blepharitis and corneal impairments, and the histology revealed epithelial thickening in the conjunctiva and the cornea with infiltration of eosinophils, mast cells and basophils. IL-5, IL-13 and CCL11 were abundant in lacrimal fluid in the mice, and the gene expressions of IL-4, IL-5, IL-13, IL-33, Prg2 and Mmcp8 were significantly increased in the cornea. Furthermore, group 2 innate lymphoid cells (ILC2) producing IL-5 and IL-13 were markedly increased in the cornea. These phenotypes closely resemble human atopic keratoconjunctivitis (AKC). The characteristic ocular phenotype in these mice strongly suggests that IL-33 is crucial for the development of AKC. The mouse line may be useful as a novel model for research and development of therapeutic strategies for AKC.

Availability of immunocytochemistry using cocktail antibody targeting p63/cytokeratin14 for the differential diagnosis of fibroadenoma and ductal carcinoma in situ in fine needle aspiration cytology of the breast.

OBJECTIVE: The differential diagnosis of fibroadenoma (FA) and ductal carcinoma in situ (DCIS) has been problematic in fine needle aspiration biopsy (FNAC) because it has been difficult to differentiate between the "large epithelial clusters" associated with FA and those associated with DCIS. The purpose of this study was to prospectively validate the usefulness of immunocytochemical staining using cocktail antibody targeting p63/CK14 in the differential diagnosis of FA and DCIS. MATERIALS AND METHODS: Twenty patients diagnosed as having an uncertain malignant potential (indeterminate) for breast cancer on the basis of a FNAC finding were selected randomly: ten patients with FA and ten with DCIS. The cover glass on a specimen stained with the Papanicolaou stain on a glass slide was peeled off, and the specimen was restained by immunocytochemical staining of cocktail antibody targeting p63 and CK14. RESULTS: Six of the twenty patients were CK14-immunopositive: FA, 6; DCIS, 0. The remaining patients were CK14-immunonegative: FA, 4; DCIS, 10. The number of CK14-immunopositive DCIS patients was significantly different from that of FA patients (P=.0054). Eight out of the twenty patients were p63-immunopositive: FA, 8; DCIS, 0. The remaining patients were p63-immunonegative: FA, 2; DCIS, 10. The number of p63-immunopositive DCIS patients was significantly different from that of FA patients (P=.0004). CONCLUSIONS: Immunocytochemical staining using cocktail antibody targeting p63/CK14 was useful for the differential diagnosis of FA and DCIS in FNAC of the breast.

Epithelial cell migration requires the interaction between the vimentin and keratin intermediate filaments.

Epithelial migration plays a central role in development, wound repair and tumor metastasis, but the role of intermediate filament in this important event is unknown. We showed recently that vimentin coexists in the same cell with keratin-KRT14 at the leading edge of the migrating epidermal cells, and knockdown of vimentin impaired colony growth. Here we demonstrate that vimentin co-localizes and co-immunoprecipitates with keratin-KRT14, and mutations in the -YRKLLEGEE- sequence of vimentin significantly reduced migration of the keratinocytes. Our data demonstrates that keratinocyte migration requires the interaction between vimentin and keratins at the -YRKLLEGEE- sequence at the helical 2B domain of vimentin. These findings have broad implications for understanding the roles of vimentin intermediate filaments in normal and neoplastic epithelial cells.

Altered expression of keratin 14 in lesional epidermis of autoimmune skin diseases.

BACKGROUND: Keratin 14 (K14) is an intermediate filament protein that is mainly expressed in the basal layer of healthy stratified epithelia. K14 has been identified as an autoantigen in the autoimmune-mediated skin disease of Scurfy mice and patients with the "immune dysregulation polyendocrinopathy, enteropathy, and X-linked" syndrome. OBJECTIVES: To examine whether K14 is a target protein in autoimmune skin diseases (ASD), we analyzed the expression pattern of K14 in lesional skin of patients with lichen ruber, cutaneous lupus erythematosus, dermatomyositis, graft-versus-host disease, psoriasis, and pemphigus vulgaris, and evaluated the reactivity of patient sera with recombinantly expressed and epidermis-derived K14. METHODS: K14 expression was analyzed by immunohistochemistry on paraffin-embedded tissue sections of 17 healthy individuals and 58 patients with ASD. Sera from 10 healthy individuals and 41 patients with ASD were analyzed by Western blot for the presence of anti-K14 autoantibodies. RESULTS: In skin of patients with ASD, K14 expression is retained in suprabasal layers. In ASD with interface dermatitis, we observed focal loss of K14 within the basal layer and in hair follicles as well. A scattered dot-like K14 staining is seen in papillary dermis, most prominently in cutaneous lupus erythematosus and lichen ruber. Using Western blot, we show that sera of different patients with ASD recognize recombinantly expressed K14. CONCLUSION: We show focal loss of K14 in the basal epidermis correlating with interface dermatitis and hair follicle involvement. Moreover, enhanced reactivity of sera of patients with atopic dermatitis with K14 suggests K14 may function as an autoantigen in ASD.

Coordinate expression of cytokeratins 7 and 14, vimentin, and Bcl-2 in canine cutaneous epithelial tumors and cysts.

Forty-seven canine cutaneous epithelial tumors and cysts were examined to determine coordinate expression of cytokeratins 7 (CK7) and 14 (CK14), vimentin, and Bcl-2 using commercially available antibodies. Within non-affected normal skin adjacent to tumors or cysts, CK7 expression was observed in luminal cells in apocrine glands; CK14 expression was observed in the stratum basale, stratum spinosum, stratum granulosum, basal layer of outer root sheath, sebaceous glands, and myoepithelial cells of apocrine glands; vimentin expression was observed in dermal papilla and scattered non-epithelial cells within the epidermis; and Bcl-2 expression was observed in scattered non-epithelial cells in the epidermis and some apocrine glands. The pattern of expression of CK7 and CK14 in cases of adenocarcinoma of the apocrine gland of the anal sac (CK7+/CK14-) and hepatoid gland tumors (CK7-/CK14+) may prove useful for diagnostic purposes. Loss of expression of CK14 and vimentin, identifying myoepithelial cells, was observed in apocrine and ceruminous adenocarcinomas. Differences in patterns of expression of Bcl-2 were observed between infundibular keratinizing acanthomas compared to trichoepitheliomas.

Using immunofluorescence (antigen) mapping in the diagnosis and classification of epidermolysis bullosa: a first report from Iran.

BACKGROUND: Immunofluorescence antigen mapping (IFM), is a newly introduced technique for diagnosis and classification of epidermolysis bullosa (EB) disease. The precise level of skin cleavage can be determined using monoclonal antibodies to EB-specific basement membrane zone protein. OBJECTIVE: To apply IFM technique in diagnosis and classification of EB and to identify utility and limitation of this method in our clinical setting. METHODS: IFM was done according to a described protocol by Pohla-Gubo et al. Monoclonal antibodies used for antigen mapping were against cytokeratin 5, cytokeratin 14, α6 integrin, ß4 integrin, laminin 332, Collagen IV, and Collagen VII. RESULTS: IFM was done for 95 referred patients, compromising 49 females and 46 males, aged 5 days to 45 years (mean = 9.5 years). Ninety cases were diagnosed with EB and classified as follows: EB simplex: (n = 13), junctional EB (n = 14), dystrophic EB (n = 62), and Kindler syndrome (n = 1). Diagnosis was not made in five cases as their specimens contained no blister. Confirmatory genetic analysis was done for five junctional cases from two families with clinical features of laryngo-onycho-cutaneous syndrome. Genetic molecular studies showed nonsense mutations in the last codon of exon 39 of the laminin α3a (LAMA3) gene (p.Gln57X) and a donor splice site mutation in LAMA3 (IVS57+5G>A) in the first and second family, respectively. CONCLUSION: IFM technique is relatively simple to perform, and interpretation of the results is not sophisticated. The proportion of inconclusive results will be decreased if the specimens contain freshly induced blister.

Immunofluorescence mapping in inherited epidermolysis bullosa: a study of 86 cases from India.

BACKGROUND: Epidermolysis bullosa (EB) poses diagnostic challenges in infancy. In India, the diagnosis is largely clinical. There were no facilities to perform immunofluorescence mapping (IFM) until recently, and electron microscopy, which requires expertise to interpret, is limited to a few research laboratories. OBJECTIVES: To describe the patterns of IFM staining in the various forms of EB in Indian patients and to correlate these findings with clinical diagnosis. METHODS: We conducted a cross-sectional study of IFM findings in EB. Antibodies against type IV collagen, cytokeratin 14, laminin 332 and type VII collagen were used. Clinical correlation was performed in all cases, and concordance-discordance rates were calculated. RESULTS: Eighty-six patients with a diagnosis of EB were included in the study. There were 29 with EB simplex (EBS), 18 with junctional EB (JEB) and 15 with dystrophic EB (DEB). The remaining 24 cases included rare variants, cases with overlapping clinical features and cases where the type of EB was not known. On IFM diagnosis, there were 32 cases of EBS, 15 JEB, 17 DEB and two Kindler syndrome. Two cases were not EB and 18 were inconclusive. IFM could establish the type in 12 of 15 cases (80%) that had overlapping clinical features. Most of these cases were under 1 year of age. Overall the concordance was 57% and was seen best in cases of EBS. CONCLUSIONS: This is the first large study of IFM of the subtypes of EB in Indian patients. The study provides a framework for better understanding of EB in Indian patients and for better diagnosis and management, particularly in infancy.

The clinical use of a P63/cytokeratin7/18/cytokeratin5/14 antibody cocktail in diagnostic breast pathology.

An antibody cocktail directed against p63, cytokeratin (CK)5/14, and CK7/18 is reported to be useful in distinguishing noninvasive from invasive breast lesions and for the characterization of intraductal epithelial proliferations. However, limited studies evaluate its use in clinical practice. A retrospective review of breast material at a university medical center identified cases that were immunostained with the above antibody cocktail. Additional p63 immunostaining alone was performed to further determine the utility of the antibody cocktail in the evaluation of invasion. Of 50 breast cases identified, the antibody cocktail was used to confirm or exclude invasion in 44 (88%). Twenty-two (50%) of these had easily identifiable p63/CK5/14-positive myoepithelial cells, whereas the remainder lacked such staining, confirming the diagnosis of invasive carcinoma. In 27 cases with available diagnostic material for additional p63 immunostaining, the cocktail better highlighted myoepithelial cells by staining nuclei and cytoplasm. Easier identification of invasion was also facilitated by CK7/18 expression in invasive foci, especially those composed of single cells. Ten cases were immunostained to help determine the nature of an intraductal proliferation. The cocktail demonstrated a mosaic staining pattern of both CK7/18- and CK5/14-positive epithelial cells in 3 (30%) cases consistent with usual hyperplasia; homogenous CK7/18 expression in the remaining cases supported the diagnosis of atypical ductal hyperplasia or carcinoma in situ. In summary, the p63/CK7/18/CK5/14 cocktail stain appears to be a useful tool in diagnostic breast pathology, in the evaluation of possible invasion, particularly in the setting of minute foci of invasion as well as in epithelial proliferations.

Id4 protein is highly expressed in triple-negative breast carcinomas: possible implications for BRCA1 downregulation.

BRCA1 germline mutation carriers usually develop ER, PR and HER2 negative breast carcinoma. Somatic BRCA1 mutations are rare in sporadic breast cancers, but other mechanisms could impair BRCA1 functions in these tumors, particularly in triple-negative breast carcinomas (TNBCs). Id4, a helix-loop-helix DNA binding factor, blocks BRCA1 gene transcription in vitro and could downregulate BRCA1 in vivo. We compared Id4 immunoreactivity in 101 TNBCs versus 113 non-TNBCs, and correlated the results with tumor morphology and immunoreactivity for CK5/6, CK14, EGFR, and androgen receptor (AR). Id4 was present in 76 out of 101 (75 %) TNBCs: 40 (40 %) TNBCs displayed Id4 positivity in >50 % of neoplastic cells, 23 (23 %) in 5-50 %, and 13 (13 %) in <5 %. In contrast, only 6 (5 %) of 113 non-TNBCs showed focal Id4 positivity, limited to fewer than 5 % of the tumor (p < 0.0001). Id4 expression significantly associated with high histologic grade (p = 0.0002) and mitotic rate (p = 0.006). Id4 decorated all 12 TNBCs with large central acellular zone of necrosis in our series, with positive staining in 10-90 % of the cells. Id4 signal strongly correlated with cytokeratin CK14 reactivity (p < 0.0001), but not with CK5/6 and EGFR. All apocrine carcinomas in our series were positive for AR and most for EGFR, but they were negative for CK5/6, CK14, and Id4, with only two exceptions. Our results document substantial expression of Id4 in most TNBCs, which could result in functional downregulation of BRCA1 pathways in these tumors.

Soluble peptide treatment reverses CD8 T-cell-induced disease in a mouse model of spontaneous tissue-selective autoimmunity.

Transgenic (Tg) mouse models of autoimmunity have been used to express model antigens that can be recognized by T cells or by autoantibodies. To identify mechanisms of CD8-mediated tissue-specific autoimmune reactions and to identify potential treatments, we generated a double-transgenic (DTg) murine model of autoimmunity by crossing keratin-14 (K14)-soluble chicken ovalbumin (sOVA) mice, which express sOVA predominantly in external ear skin, with OT-I mice whose CD8 T cells express Vα2/Vß5 regions of the TCR and are specific for SIINFEKL peptide (chicken ovalbumin (OVA) peptide 257-264) in association with class I major histocompatibility complex. The K14-sOVA/OT-I DTg mice develop a destructive process selectively targeting the external ear pinnae in the first 6 days of life. The ear bud area develops an intense inflammatory infiltrate of OT-I cells. Administration of the SIINFEKL peptide intravenously to pregnant F1 (filial 1, first filial generation of animal offspring from cross-mating two parental types) mice and subsequently intraperitoneally to newborn pups resulted in normal external ear development. Treatment with this self-peptide markedly reduced OT-I cell numbers, as well as downregulated the CD8 co-receptor. This model can be useful in studying localized, tissue-specific, immune-mediated skin disease, and provide information about potential therapies for autoimmune diseases in which specific molecular targets are known.

Integrating chemistry and immunology in allergic contact dermatitis: more questions than answers?

In this issue, Simonsson and colleagues shed light on the chemical mechanisms determining hapten formation in the skin, which precede the elicitation of an antigen-specific immune response in allergic contact dermatitis. Combining fluorescence microscopy, proteomics, and mass spectrometry, the investigators identified keratins K5 and K14, particularly cysteine 54 of K5, in the human basal epidermal layer as the major molecular targets of caged thiol-reactive fluorescent haptens (i.e., bromobimanes). Anti-keratin antibody responses in mice exposed to bromobimanes suggest the generation of immunogenic epitopes by cysteine-reactive haptens. Although many issues await further investigation, Simonsson and co-workers' observations advance our understanding of the molecular basis of hapten-protein complex formation in skin.

Consequences of two different amino-acid substitutions at the same codon in KRT14 indicate definitive roles of structural distortion in epidermolysis bullosa simplex pathogenesis.

Numerous inherited diseases develop due to missense mutations, leading to an amino-acid substitution. Whether an amino-acid change is pathogenic depends on the level of deleterious effects caused by the amino-acid alteration. We show an example of different structural and phenotypic consequences caused by two individual amino-acid changes at the same position. Epidermolysis bullosa simplex (EBS) is a genodermatosis resulting from KRT5 or KRT14 mutations. Mutation analysis of an EBS family revealed that affected individuals were heterozygous for a, to our knowledge, previously unreported mutation of c.1237G>C (p.Ala413Pro) in KRT14. Interestingly, 2 of 100 unrelated normal controls were heterozygous, and 1 of the 100 was homozygous for a different mutation in this position, c.1237G>A (p.Ala413Thr). In silico modeling of the protein demonstrated deleterious structural effects from proline substitution but not from threonine substitution. In vitro transfection studies revealed a significantly larger number of keratin-clumped cells in HaCaT cells transfected with mutant KRT14 complementary DNA (cDNA) harboring p.Ala413Pro than those transfected with wild-type KRT14 cDNA or mutant KRT14 cDNA harboring p.Ala413Thr. These results show that changes in two distinct amino acids at a locus are destined to elicit different phenotypes due to the degree of structural distortion resulting from the amino-acid alterations.

Thymic microenvironment reconstitution after postnatal human thymus transplantation.

A functional thymus develops after cultured thymus tissue is transplanted into subjects with complete DiGeorge anomaly. To gain insight into how the process occurs, 7 post-transplantation thymus biopsy tissues were evaluated. In 5 of 7 biopsies, the thymus appeared to be predominantly cortex with thymocytes expressing cortical markers. Unexpectedly, the epithelium expressed both cortical [cortical dendritic reticulum antigen 2 (CDR2)] and medullary [cytokeratin (CK) 14] markers. Early medullary development was suggested by epithelial cell adhesion molecule (EpCAM) reactivity in small areas of biopsies. Two other biopsies had distinct mature cortex and medulla with normal restriction of CK14 to the medulla and subcapsular cortex, and of CDR2 to cortex. These data are consistent with a model in which thymic epithelium contains CK14+ "progenitor epithelial cells". After transplantation these cells proliferate as CK14+CDR2+ thymic epithelial cells that are associated with cortical thymocytes. Later these cells differentiate into distinct cortical and medullary epithelia.

Rapid multiplex immunohistochemistry using the 4-antibody cocktail YANA-4 in differentiating primary adenocarcinoma from squamous cell carcinoma of the lung.

The current Food and Drug Administration-approved standard treatment for non-small cell carcinomas consists of carboplatin/taxol/avastin. However, nowadays more specialized protocols, depending on tumor subtype, are being used for lung cancer patients. Therefore, accurate differentiation between adenocarcinoma and squamous cell carcinoma is essential for the selection of appropriate therapies. We designed a rapid multiplex immunostaining method using a novel 4-antibody cocktail, YANA-4. This antibody cocktail consists of the following monoclonal antibodies: rabbit for thyroid transcription factor 1(TTF-1), mouse for napsin A, mouse l for p63, and rabbit for CK14. All procedures can be completed within 3 hours. This method labels the nuclei of adenocarcinomas as brown with TTF-1, and cytoplasm as blue with napsin A. Squamous cell carcinomas could be differentiated from adenocarcinomas with an inverse staining pattern: blue nuclei with p63 and brown cytoplasm with CK14. In this study, 97.4% (38 of 39) of adenocarcinomas showed brown nuclei (TTF-1) and/or blue cytoplasm (napsin A), with 4 cases showing positivity only for brown nuclei (TTF-1) and 1 case only for blue cytoplasm (napsin A). None of the squamous cell carcinoma cases showed these staining patterns. Positivity for blue nuclei (p63) and/or brown cytoplasm (CK14) was detected in 100% (25 of 25) of squamous cell carcinomas, with 1 case showing positivity only for brown cytoplasm (CK14) and 2 cases only for blue nuclei (p63). None of the adenocarcinoma cases showed these patterns. This rapid immunohistochemical method can thus be considered highly specific and sensitive for differentiating adenocarcinomas and squamous cell carcinomas.

Caged fluorescent haptens reveal the generation of cryptic epitopes in allergic contact dermatitis.

Allergic contact dermatitis (ACD) is the most prevalent form of human immunotoxicity. It is caused by skin exposure to haptens, i.e., protein-reactive, low-molecular-weight chemical compounds, which form hapten-protein complexes (HPCs) in the skin, triggering the immune system. These immunogenic HPCs are elusive. In this study a series of thiol-reactive caged fluorescent haptens, i.e., bromobimanes, were deployed in combination with two-photon fluorescence microscopy, immunohistochemistry, and proteomics to identify possible hapten targets in proteins in human skin. Key targets found were the basal keratinocytes and the keratins K5 and K14. Particularly, cysteine 54 of K5 was found to be haptenated by the bromobimanes. In addition, elevated levels of anti-keratin antibodies were found in the sera of mice exposed to bromobimanes in vivo. The results indicate a general mechanism in which thiol-reactive haptens generate cryptic epitopes normally concealed from the immune system. In addition, keratinocytes and keratin seem to have an important role in the mechanism behind ACD, which is a subject for further investigations.

Autoantibodies in scurfy mice and IPEX patients recognize keratin 14.

Scurfy mice have a deletion in the Foxp3 gene, resulting in a failure to generate Foxp3(+) regulatory T cells, and they subsequently develop severe CD4(+) T-cell-mediated autoimmune inflammation. Multiple organs are involved, but the skin is one of the main organs affected. During the course of disease, Scurfy mice develop autoantibodies; however, the targeted antigens are unknown. In this study, we show that Scurfy mice develop autoantibodies directed against skin antigens. Using western blot analysis, we found that Scurfy serum reacted with proteins in total skin lysate, as well as in a keratinocyte lysate. Most of the Scurfy sera tested identified a major band at 50 kDa. Transfer of Scurfy CD4(+) T cells into nu/nu mice yielded autoantibodies with similar reactivity. Further analysis using 2D western blots, followed by peptide mass fingerprinting, identified several keratins as targets. To confirm this observation, we chose one of the identified targets, keratin 14, and prepared recombinant proteins encompassing the N-terminal, middle, and C-terminal portions of the keratin 14 protein. Scurfy serum predominantly recognized the C-terminal fragment. Sera from patients with immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, the human disease resulting from FOXP3 mutations, also recognized skin antigens, including keratin 14. Thus, the results of our study indicate that autoantibodies in Scurfy mice and patients with IPEX target keratins.

VCAM-1 blockade delays disease onset, reduces disease severity and inflammatory cells in an atopic dermatitis model.

We investigated the functions of critical adhesion molecules ICAM-1 and VCAM-1 in a keratin-14 IL-4-transgenic (Tg) mouse model of atopic dermatitis, the skin lesions of which are characterized by prominent inflammatory cell infiltration, significantly increased mRNAs and proteins of ICAM-1, VCAM-1, E-selectin, P-selectin, L-selectin, and PSGL-1, and significantly increased numbers of dermal vessels expressing these adhesion molecules. We tested the hypotheses that deletion or blockade of these molecules may impede the inflammation by examining the disease progresses in the Tg mice crossed with ICAM-1-knockout mice and Tg mice received anti-VCAM-1-neutralizing antibody. Although the findings of the ICAM-1-knockout Tg mice (Tg/ICAM-1(-/-)) developed skin lesions similar to wide-type ICAM-1 Tg mice (Tg/ICAM-1(+/+)) were surprising, a compensatory mechanism may account for it: the frequency of VCAM-1 ligand, CD49d, on CD3(+) T cells in the lesional skin significantly increased in the Tg/ICAM-1(-/-) mouse, compared with the Tg/ICAM-1(+/+) mice. In contrast, anti-VCAM-1-treated Tg/ICAM-1(-/-) or Tg/ICAM-1(+/+) mice had significantly delayed onset of skin inflammation compared with isotype antibody-treated groups. Moreover, anti-VCAM-1 significantly reduced the skin inflammation severity in Tg/ICAM-1(+/+) mice, accompanied with reduction of mast cell, eosinophil, and CD3(+) T cell infiltration. VCAM-1 is more critical in developing skin inflammation in this model.