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In the pathogenesis of atopic dermatitis (AD), skin barrier dysfunction and T-helper (Th) type 2 immune reactions play important roles. Alterations in the stratum spinosum of AD have not been studied in much detail. In this study, we investigated the changes of structural proteins and adhesion molecules residing in the stratum spinosum of AD lesional skin, and whether Th2 cytokines including interleukin (IL)-4 and IL-13 alter the expression of these proteins. Skin samples were collected from patients with AD and from healthy controls. Normal human epidermal keratinocytes were cultured and differentiated in the presence or absence of either IL-4 or IL-13 in vitro. The expression of keratin 1, keratin 10, desmoglein 1 and desmocollin 1 was examined by immunofluorescence and western blotting. The expression of these proteins was downregulated in AD lesional skin, and IL-4 and IL-13 were shown to suppress their expression. These results suggest that the stratum spinosum is impaired in AD lesional skin, possibly by Th2 cytokines, which may be involved in the pathogenesis of AD.

Anti-endothelial cell antibodies (AECAs) are usually directed against the surface antigens on the vascular endothelial cells. Clinical studies suggest a pathogenic role for nonhuman leukocyte antigen in antibody-mediated rejection; however, the antigens on the donor vascular endothelium that serve as the first-line targets for an immune response during allograft rejection have not been fully identified. Here, we used immunoprecipitation and mass spectrometry to identify antigens from the sera of kidney transplant recipients who were experiencing antibody-mediated rejection. Keratin 1 (KRT1) was identified as a novel antigenic target expressed on endothelial cells. To validate our finding, we produced recombinant proteins representing the three most common alleles of KRT1. The serum used for immunoprecipitation showed a strong reaction to KRT1 recombinants in western blot and ELISA. In the kidney transplant cohort, more AECA-positive recipients than AECA-negative recipients had KRT1 antibodies (32.2% versus 11.9%, p = 0.002). Sera from 255 renal recipients were tested by ELISA. Of the 77 recipients with deteriorating graft function (serum creatinine > 120  μ mol/L), 23 had anti-KRT1 antibodies. KRT1-IgG positivity was, therefore, associated with a higher risk of kidney transplant rejection (29.9% (23/77) versus 16.9% (30/178), p = 0.0187). A better understanding of this antigenic target will improve long-term allograft survival., Competing Interests: The authors declare that they have no competing interests.

Keratin 1 is found in the upper layers of the epidermis, on the surface of endothelial cells and in the membrane of the neuroblastoma NMB7. It is important for the structural integrity of the skin, has been found to regulate the activity of kinases, such as protein kinase C (PKC) and SRC, to participate in complement activation by the lectin pathway and to be involved in fibrinolysis, angiogenesis and the response to oxidative stress. Studies of the polymorphisms of the Keratin 1 (KRT1) gene have been driven mostly by interest in its role in skin diseases. However, much of the KRT1 variation occurs in normal populations and is not associated with dermal pathology. In the present experiments, we have investigated the polymorphism of KRT1 genes by nucleotide sequencing in normal families and normal populations of European, African, Hispanic and Asian background. The frequencies of the KRT1 alleles were strikingly different in the four ethnic groups and most of the mutations resulted in amino acid substitutions, with only 3 out of 19 being synonymous. Analysis of selective neutrality by the Ewens-Watterson and Tajima D statistics showed that KRT1 allele homozygosity was decreased in three of the populations suggesting that KRT1 genes may be under the influence of balancing selection. It is possible that the role of KRT1 as a receptor, rather than its structural function in the epidermis, is what drives the selective forces that are apparent in the inheritance of this gene., (Copyright © 2013. Published by Elsevier Inc.)

It has been known for some time that transplant recipients may have antibodies to endothelial cells which are not detected on lymphocytes. However, little progress has been made in the analysis of these endothelial antigens. In the present experiments we have attempted to characterize endothelial cell surface antigens to which antibodies were produced during graft rejection. We have used a panel of endothelial cells from umbilical cord veins and found that antibodies with a polymorphic pattern in the panel appeared to correlate with transplant failure of kidney allografts and with the development of transplant-related coronary artery disease (TCAD) in heart transplant recipients. Among 39 patients with kidney allografts, 21 were negative for antibodies to endothelial cells and did well and 18 were positive and had frequent transplant loss (p=0.001). In 18 patients with TCAD and 20 patients of a comparator group without TCAD, association of coronary disease with endothelial cell antibodies was observed (p<0.02). To characterize the endothelial antigens responsible for these serologic reactions we performed immunoprecipitation of reactive antibodies with the corresponding endothelial cell surface antigens, followed by protein identification of the target antigens. Nine proteins were identified in these experiments, 5 were non-polymorphic and appeared to represent autoantigens. Four of the isolated proteins appeared to be polymorphic. They were the Human Major Histocompatibility Complex class I chain-related gene A (MICA), already known to be associated with antibody production and graft failure, human keratin 1, a protein known to be polymorphic and expressed on the surface of endothelial cells, eukaryotic translation initiation factor (EIF) 2A and ErbB3-binding protein 1. The possible role of keratin 1 and the other antigens in allograft rejection requires further investigation., (Copyright © 2013. Published by Elsevier Inc.)

An analysis of latent fingermark residues by Sodium-Dodecyl-Sulfate PolyAcrylamide Gel Electrophoresis (SDS-PAGE) followed by silver staining allowed the detection of different proteins, from which two major bands, corresponding to proteins of 56 and 64 kDa molecular weight, could be identified. Two other bands, corresponding to proteins of 52 and 48 kDa were also visualizable along with some other weaker bands of lower molecular weights. In order to identify these proteins, three antibodies directed against human proteins were tested on western blots of fingermarks residues: anti-keratin 1 and 10 (K1/10), anti-cathepsin-D (Cat.D) and anti-dermcidin (Derm.). The corresponding antigens are known to be present in the stratum corneum of desquamating stratified epithelium (K1/10, Cat.D) and/or in eccrine sweat (Cat.D, Derm.). The two major bands were identified as consistent with keratin 1 and 10. The pro-form and the active form of the cathepsin-D have also been identified from two other bands. Dermcidin could not be detected in the western blot. In addition, these antibodies have been tested on latent fingermarks left on polyvinylidene fluoride (PVDF) membrane, as well as on whitened and non-whitened paper. The detection of fingermarks was successful with all three antibodies.

Purpose: Several inherited corneal disorders in humans result from mutations in the transforming growth factor beta induced gene (TGFBI), which encodes for the extracellular transforming growth factor beta induced protein (TGFBIp) that is one of the most abundant proteins in the cornea. We previously reported a significant amount of TGFBIp in plasma by immunoblotting using the only TGFBIp antiserum (anti-p68(beta ig-h3)) available at that time (anti-p68(beta ig-h3) was generated against residues Val210-His683 of TGFBIp). This observation raised the possibility that a fraction of corneal TGFBIp may originate from the plasma. However, recent experiments in our laboratory indicated that the anti-p68(beta ig-h3) antiserum cross-reacts with an environmental protein contaminant. Therefore, we investigated the specificity of the originally utilized anti-p68(beta ig-h3) antiserum and re-evaluated the amount of TGFBIp in human plasma by immunoblotting using a new specific antiserum., Methods: The observed cross-reactivity of the previously utilized anti-p68(beta ig-h3) antiserum was tested by immunoblotting and the antigen identity was determined by mass spectrometry. A part of human TGFBI encoding an NH2-terminal 11.4 kDa fragment of TGFBIp (residues Gly134-Ile236) was amplified by polymerase chain reaction (PCR) and cloned in E. coli. The TGFBIp fragment was expressed in E. coli, purified by Ni2+-affinity chromatography, and used to immunize rabbits to produce a specific antiserum (anti-TGFBIp(134-236)). To enhance the detection of possible TGFBIp in plasma by allowing a higher sample load, albumin and immunoglobulin G (IgG) were specifically depleted from normal human plasma by affinity chromatography. The presence of TGFBIp in plasma was investigated by immunoblotting using the anti-TGFBIp(134-236) antiserum. Purified TGFBIp from porcine corneas was used for estimation of the TGFBIp detection limit., Results: The previously utilized TGFBIp antiserum, anti-p68(beta ig-h3), cross-reacted with human keratin-1, a common environmental protein contaminant. Thus, the anti-p68(beta ig-h3) antiserum recognizes both TGFBIp and keratin-1. In contrast, the anti-TGFBIp(134-236) antiserum reacted with TGFBIp but showed no indication of reactivity with other proteins in plasma. Using this antiserum, TGFBIp was not detected in crude or albumin/IgG-depleted human plasma and the detection limit of TGFBIp using immunoblotting was estimated to be 10 ng., Conclusions: Our failure to detect TGFBIp in human plasma using a highly specific antiserum suggests that TGFBIp is not present in a physiologically relevant concentration in human plasma. The previous impression that normal human plasma contains a significant amount of TGFBIp by immunoblotting was due to the utilization of a less specific antiserum that recognizes both TGFBIp and human keratin-1. Together with other results, our observation makes it unlikely that TGFBIp is imported into the cornea from the circulation as reported for other abundant extracellular corneal proteins and suggests corneal origin of TGFBIp deposits in individuals with inherited corneal diseases caused by mutations in the TGFBI gene.