An automated method for the quantification of immunostained human Langerhans cells

Transplantation of copper-doped calcium polyphosphate scaffolds combined with copper (II) preconditioned bone marrow mesenchymal stem cells for bone defect repair

Calcium polyphosphate is a bioactive ceramic that possesses similar mineral components to bone and possess good physicochemical properties. However, pure calcium polyphosphate scaffold is brittle, and it is insufficient in promoting vascularization and osteoinductivity. This study was conducted to assess whether copper (Cu) incorporated into calcium polyphosphate could improve the scaffolds' inherent shortcomings. In the experiments, Cu-calcium polyphosphate scaffolds' mechanical strength, biocompatibility, and biodegradability were researched primarily. And then, hypoxia-inducible factor 1-alpha expression along with angiogenesis and osteogenesis potential when the scaffolds treated with the bone marrow mesenchymal stem cells (BMMSCs) were analyzed in vitro. In in vivo studies, the Cu-calcium polyphosphate scaffolds combined with the liquid extract preconditioned BMMSCs were implanted into animal model to repair the bone defects. Meanwhile, we also evaluate the expression of angiogenic and osteogenic factors. For comparison, Cu-calcium polyphosphate, calcium polyphosphate, and blank control groups were designed. According to the results, proper content of Cu incorporated with calcium polyphosphate (0.1% Cu-calcium polyphosphate) did not significantly change the scaffold's degradation velocity, but it obtained higher compress mechanical strength and Cu-doped scaffolds were less brittle. Besides, these scaffolds incorporated with Cu showed better cytocompatibility and cell proliferation activity. Moreover, after Cu was doped, the hypoxia-inducible factor 1-alpha expression was up-regulated with the angiogenic and osteogenic factors levels increased both in in vitro and in vivo study. The bone defect healing capacity was accessed, using Cu-calcium polyphosphate combined with preconditioned BMMSCs further enhanced new bone formation and improved hypoxia-inducible factor 1-alpha, alkaline phosphatase, osteocalcin, and vascular endothelial growth factor expression. In conclusion, doped Cu into calcium polyphosphate was an alternative strategy for improving calcium polyphosphate's mechanical property and promoting the osteogenesis and angiogenesis potential. Using Cu-calcium polyphosphate scaffolds combined with Cu preconditioned BMMSCs to treat bone defect could enhance bone defect healing.

Association between the expression levels of tumor necrosis factor-α-induced protein 8 and the prognosis of patients with gastric adenocarcinoma

The present study aimed to investigate the expression levels of tumor necrosis factor-α-induced protein 8 (TNFAIP8) in gastric adenocarcinoma. TNFAIP8 expression levels in gastric adenocarcinoma tissue samples (with and without lymph node metastasis), adjacent normal tissue samples and metastatic lymph node tissue samples were detected by immunohistochemistry. The correlation between TNFAIP8 expression levels and clinicopathological data and gastric adenocarcinoma prognosis was analyzed. The results demonstrated that TNFAIP8 expression in gastric adenocarcinoma tissue samples and metastatic lymph node tissue samples markedly increased at a rate of 47.2% (50/106) and 81.7% (49/60), respectively, as compared with the adjacent normal tissue samples in which no TNGFAIP8 expression was detected (0%). This increase in TNFAIP8 expression was statistically significant. TNFAIP8 expression rates in the primary tumors (60%, 36/60) of patients with lymph node metastasis were significantly higher compared with the primary tumors of patients without lymph node metastasis (30.4%, 14/46). TNFAIP8 expression was associated with an increase in the severity of TNM stage, tumor grade, vascular invasion, lymph node metastasis and serum CA72-4 levels. The overall survival rate of patients with gastric adenocarcinoma and high TNFAIP8 expression was poorer compared with patients with low TNFAIP8 expression, and TNFAIP8 expression was negatively correlated with patient prognosis. The results also demonstrated that TNFAIP8 was an independent prognostic marker in gastric adenocarcinoma (relative risk, 1.736; P=0.029). In conclusion, the results of the present study demonstrated that TNFAIP8 expression was associated with the occurrence, development and metastasis of gastric adenocarcinoma, and negatively correlated with the prognosis of patients with gastric adenocarcinoma. TNFAIP8 may therefore serve as a prognostic factor for gastric adenocarcinoma.

The human skin/chick chorioallantoic membrane model accurately predicts the potency of cosmetic allergens

The current standard method for predicting contact allergenicity is the murine local lymph node assay (LLNA). Public objection to the use of animals in testing of cosmetics makes the development of a system that does not use sentient animals highly desirable. The chorioallantoic membrane (CAM) of the chick egg has been extensively used for the growth of normal and transformed mammalian tissues. The CAM is not innervated, and embryos are sacrificed before the development of pain perception. The aim of this study was to determine whether the sensitization phase of contact dermatitis to known cosmetic allergens can be quantified using CAM-engrafted human skin and how these results compare with published EC3 data obtained with the LLNA. We studied six common molecules used in allergen testing and quantified migration of epidermal Langerhans cells (LC) as a measure of their allergic potency. All agents with known allergic potential induced statistically significant migration of LC. The data obtained correlated well with published data for these allergens generated using the LLNA test. The human-skin CAM model therefore has great potential as an inexpensive, non-radioactive, in vivo alternative to the LLNA, which does not require the use of sentient animals. In addition, this system has the advantage of testing the allergic response of human, rather than animal skin.

Reproducibility of immunostaining quantification and description of a new digital image processing procedure for quantitative evaluation of immunohistochemistry in pathology

Quantification of immunostaining is a widely used technique in pathology. Nonetheless, techniques that rely on human vision are prone to inter- and intraobserver variability, and they are tedious and time consuming. Digital image analysis (DIA), now available in a variety of platforms, improves quantification performance: however, the stability of these different DIA systems is largely unknown. Here, we describe a method to measure the reproducibility of DIA systems. In addition, we describe a new image-processing strategy for quantitative evaluation of immunostained tissue sections using DAB/hematoxylin-stained slides. This approach is based on image subtraction, using a blue low pass filter in the optical train, followed by digital contrast and brightness enhancement. Results showed that our DIA system yields stable counts, and that this method can be used to evaluate the performance of DIA systems. The new image-processing approach creates an image that aids both human visual observation and DIA systems in assessing immunostained slides, delivers a quantitative performance similar to that of bright field imaging, gives thresholds with smaller ranges, and allows the segmentation of strongly immunostained areas, all resulting in a higher probability of representing specific staining. We believe that our approach offers important advantages to immunostaining quantification in pathology.

The lack of epithelial interleukin-7 and BAFF/BLyS gene expression in prostate cancer as a possible mechanism of tumor escape from immunosurveillance

PURPOSE

The human prostate is endowed with intraepithelial and stromal lymphocytes, which may develop lymphoid follicles (LF) and allow a local immune response. We sought to investigate whether interleukin (IL)-7 and BAFF/BLyS, two fundamental survival factors for T and B cells, are expressed in the normal and neoplastic prostate and affect intraprostatic lymphocyte homeostasis.

EXPERIMENTAL DESIGN

We have used real-time reverse transcription-PCR of microdissected prostatic glands and confocal microscopy to detect cytokine production, combined with immunohistochemistry to characterize intraprostatic lymphocytes.

RESULTS

Prostatic epithelia constitutively produce IL-7 and, to a lesser extent, BAFF/BLyS. Indeed, we show that IL-7 receptor alpha is expressed by intraepithelial T lymphocytes and parafollicular T cells, whereas BAFF-R is found on periglandular B lymphocytes and mantle zone B cells of LFs. Prostate-homing B and T lymphocytes are scarcely proliferating, whereas most of them express the antiapoptotic protein bcl-2 and reveal a low apoptotic index in the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. The transition from normal to neoplastic glands in prostate cancer (PCa) is marked by a dramatic decline of IL-7 and BAFF/BLyS production. Accordingly, PCa is characterized by a significant reduction of intraepithelial lymphocytes and loss of LFs. B-cell and T-cell expression of bcl-2 decrease, whereas the apoptotic events increase. The remaining PCa-infiltrating lymphocytes are mostly CD8(+) T cells that lack terminal differentiation and barely penetrate neoplastic glands.

CONCLUSIONS

These results suggest that epithelial IL-7 and BAFF/BLyS production support intraprostatic lymphocyte survival. Its loss in PCa is associated with a severe depletion of prostate-associated lymphocytes and points to a novel tumor escape mechanism.

Terminal differentiation and mitogen-activated protein kinase signaling in human cholesteatoma epithelium

OBJECTIVES

To investigate whether--in cholesteatoma epithelium--terminal differentiation, resulting in high involucrin expression, is associated with mitogen-activated protein kinase (MAPK) signaling.

BACKGROUND

Alterations in specific signal transduction pathways may explain abnormal differentiation of the keratinocytes in cholesteatoma. Signaling pathways used by eukaryotic cells to transduce extracellular signals into cellular responses converge on activated mitogen-activated protein kinases, mainly extracellular signal-regulated kinase, c-Jun NH2-terminal kinase, and p38.

METHODS

Tissue samples were taken from 16 patients with acquired cholesteatoma. Histologic examination showed that 12 of the 16 cholesteatomas were inflamed. Immunohistochemical methods were used to determine expressions of involucrin and the activated form of p38, extracellular signal-regulated kinase, and c-Jun NH2-terminal kinase proteins. The results obtained from cholesteatoma tissue were compared with paired control samples from retroauricular skin.

RESULTS

We demonstrated increased levels of involucrin and increased levels of the activated forms of p38 and ERK1/2 in cholesteatoma epithelium when compared with control samples. No abnormality was found in the activation and expression of JNK1/2. A positive correlation was found between p38, pERK1/2, and involucrin expression (p<0.05).

CONCLUSION

Our results demonstrate that signaling via the mitogen-activated protein kinases ERK1/2 and p38 is increased in cholesteatoma epithelium when compared with control skin. The correlations between involucrin-and phosphorylated pERK1/2 expression and between involucrin-and phosphorylated p38 expression indicates that terminal differentiation in cholesteatoma epithelium proceeds via activation of these mitogen-activated protein kinase signaling pathways. We discussed whether this increased mitogen-activated protein kinase-driven terminal differentiation is probably part of a keratinocyte survival program or caused by an inflammation-induced cellular stress response.

Survival signaling and terminal differentiation in cholesteatoma epithelium

CONCLUSION

There is a strong indication that epithelial keratinocytes in cholesteatoma are protected against apoptosis. The late terminal differentiation program in cholesteatoma epithelium is disturbed.

OBJECTIVES

Previously, minimal apoptosis has been demonstrated in cholesteatoma epithelium. The phosphoinositide 3-kinase/Akt/protein kinase B (PI3K/Akt/PKB) and the mitogen activated protein kinases (MAPK) signaling transduction pathways have been reported to protect epithelial cells against apoptosis. Both pathways have also been proven to regulate late terminal differentiation of keratinocytes. In cholesteatoma epithelium, MAPK activation has been shown to be associated with terminal differentiation. The purpose of this study was to investigate whether in human cholesteatoma epithelium protection against programmed cell death by means of PI3K/Akt survival signaling is present and associated with MAPK activation and terminal differentiation.

MATERIALS AND METHODS

Fifteen human cholesteatoma and patient-matched retro-auricular skin samples were immunohistochemically stained for pAkt/PKB, phosphorylated extracellular regulated kinase1/2 (pERK1/2), phosphorylated JNK/SAPK, phosphorylated p38, involucrin and filaggrin. Positive cells were counted by computer-assisted digital image analysis.

RESULTS

Protein expressions of pAkt/PKB, pERK1/2, pp38, and involucrin in cholesteatoma epithelium were significantly increased when compared with retro-auricular skin (p<0.01). Filaggrin expression was significantly decreased (p=0.03). The positive correlation was confirmed between both pERK1/2 and pp38, and involucrin (p < or = 0.05).

Quilty effect has the features of lymphoid neogenesis and shares CXCL13-CXCR5 pathway with recurrent acute cardiac rejections

Quilty effect (QE) is a frequent, yet enigmatic feature of cardiac allograft, since it is apparently devoid of clinical significance, though its association with acute (A) rejection (R) is strongly suspected. It was observed in 126/379 biopsies from 22 patients during the first posttransplant year. Most grade (G)2R biopsies displayed a concomitant QE. The following features typical of QE were identified: (a) focal angiogenesis and lymphangiogenesis associated with bFGF, VEGF-C and VEGF-A expression, (b) marked infiltrate of CD4(+)T and CD20(+)B followed by CD8(+)T lymphocytes arranged around PNAd(+)HEV-like vessels. Most QE appear as distinct B-T-cell-specific areas with lymphoid follicles sometimes endowed with germinal center-like structures containing VCAM-1(+)CD21(+)FDC and CD68(+)macrophages, which frequently expressed CXCL13. These cells were also found in mantle-like zones, where small lymphocytes expressed CXCR5, otherwise in the whole area of not clustered lymphoid aggregates. CXCL13 was also expressed, in association with CD20(+)B lymphocyte recruitment, in G2R biopsies obtained from patients with recurrent AR. QE has features of a tertiary lymphoid tissue suggesting an attempt, by the heart allograft, to mount a local response to a persistent alloantigen stimulation resulting in aberrant CXCL13 production, as also occurs in recurrent AR. CXCL13-CXCR5 emerge as a common molecular pathway for QE and recurrent episodes of AR.

Endomyocardial infiltration by B and NK cells foreshadows the recurrence of cardiac allograft rejection

Heart allograft outcome is unpredictable and acute rejection episodes still occur despite the improvement of immunosuppressive regimens. We therefore investigated whether the immunopathological profile of endomyocardial biopsies might underlie the variations in the clinical course of a graft. Biopsies from transplanted patients were analysed by histology, immunohistochemistry (associated with digital image analysis), confocal and electron microscopy to determine the type and the functional state of leukocytes infiltrating the myocardium, together with their ultrastructural features and those of the graft itself. In comparison with biopsies with grade 0R or grade 1R rejection, those from patients with grade 2R rejection displayed significant infiltration of macrophages, T lymphocytes, and CD83+ and DC-SIGN+ dendritic cells. Fifty-seven per cent were invaded by CD20+B lymphocytes, most of which expressed CD69 activation marker and cooperated in interleukin-12 production, and by CD69+CD94+NK cells expressing interferon-gamma. Ultrastructural signs of myocyte degeneration and microvessel rupture by NK cells were frequent. These patients developed recurrent episodes of acute allograft rejection. Endomyocardial B and NK infiltrates are involved in the dynamics of allograft rejection and are associated with a high risk of its recurrence. Immunopathological assessment of endomyocardial biopsies may thus serve to forecast the probable outcome of a heart allograft.

Skin irritants and contact sensitizers induce Langerhans cell migration and maturation at irritant concentration

Skin irritants and contact allergens reduce the number of Langerhans cells (LCs). It has been assumed that this reduction is due their migration to the draining lymph node (LN) for initiating immune sensitization in a host. Skin irritation, however, as opposed to contact allergy is not considered to be an immunological disease. Nevertheless, skin irritants are also known for their adjuvant-like effects on contact allergy, resulting in skin hypersensitivity reactions like toxic dermatitis. The human organotypic skin explant culture (hOSEC) model is used to study the characteristics of chemical-induced migration of CD1a(+) LCs out of the epidermis in relation to irritancy or toxicity. We analysed cells emigrating out of hOSEC for CD1a(+) LCs, CD83(+) mature dendritic cells (DCs) and CCR7(+) LN homing cells. After exposure to a toxic concentration of a non-immunogenic irritant, an increase of CD1a(+)CD83(+) LCs was found in the culture medium. A non-toxic concentration of an sensitizer induced an increase of CD1a(+) cells. About 50% of skin emigrating CD1a(+) LCs were CD83(-) (immature) but all were CCR7(+). Skin irritation by both non-allergenic and allergenic compounds induces LC migration and maturation. In contrast, only allergenic compounds induced LC migration with partial maturation at subtoxic concentration. This effectively demonstrates that irritation is physiologically needed stimuli for inducing LC maturation.

Assessment of contact allergens by dissociation of irritant and sensitizing properties

The human organotypic skin explant culture (hOSEC) model is a promising alternative in vitro model for screening contact allergens. In this model, the chemical-induced migration of Langerhans cells (LCs) out of the epidermis, evaluated after a 24-h exposure period, is used as a measure of sensitizer potential. As skin irritants can also induce LC migration it is essential that concentrations of test chemicals are used that are not even weakly irritant. Using the hOSEC irritation model chemicals are classified as weak irritants if they are toxic after a 48-h exposure period. Toxicity is determined by methyl green-pyronine (MGP) staining of hOSEC. We studied three frequently used non-sensitizing skin irritants and six potent or frequent human sensitizers in a dose-response. A complete discrimination between non-sensitizers and contact sensitizers was obtained for the chemicals tested when the concentrations used were lower than the weak irritant concentrations. Frequency of positive allergen reactions in patch test of human populations correlated with the difference between weak irritant concentrations and the lowest concentration inducing significant LC migration. Sensitizer potency correlated with chemical irritancy as determined by keratinocyte death. For the compounds tested, the hOSEC model predicted allergenicity in humans better than the guinea pig maximization test and the mouse local lymph node assay.

Sustained extracellular signal-regulated kinase1/2 mitogen-activated protein kinase signalling is related to increased p21 expression in cholesteatoma epithelium

CONCLUSION

These results show for the first time that the RAS/RAF/ERK1/2 MAPK signalling pathway is active and involved in p21-mediated cell cycle arrest in human cholesteatoma epithelium.

OBJECTIVE

In a previous report we have demonstrated that the epithelium in human cholesteatoma is characterized by high p53-dependent p21 expression. The RAS/RAF/extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) signalling pathway can induce p21 expression and subsequent cell cycle arrest via p53-dependent or -independent mechanisms. We designed the present study to investigate whether the RAS/RAF/ERK1/2 MAPK signalling pathway is involved in p53-dependent and p21-mediated cell cycle arrest in human cholesteatoma.

MATERIAL AND METHODS

A total of 18 cholesteatoma samples and 18 paired control retro-auricular skin samples were immunohistochemically stained for p53, p21, phosphorylated ERK1/2 (pERK1/2) and total ERK1/2. Positive cells were counted by means of digital image analysis. Double-label fluorescence immunohistochemistry was performed to demonstrate co-expression of p21 and pERK1/2.

RESULTS

Protein expression of p53, p21 and pERK1/2 differed significantly between cholesteatoma epithelium and retro-auricular skin (p <0.01). In cholesteatoma, co-expression of p21 and pERK1/2 was prominent, whereas in retro-auricular skin there was hardly any co-expression. Positive correlations were found between p53 and p21 (p =0.003) and between p21 and pERK1/2 (p =0.013).

A two-centre evaluation of the human organotypic skin explant culture model for screening contact allergens

Animal models are considered to be the "gold standard" for determining the potential contact allergenicity of low molecular weight chemicals. However, governmental regulations and ethical considerations limit the use of animals for such purposes. There is therefore a need for in vitro alternative models. The human organotypic skin explant culture (HOSEC) model is reported to be a promising alternative method for the predictive testing of contact allergens. The accelerated migration of Langerhans cells from the epidermis upon exposure to contact allergens is used to identify chemicals that are potentially capable of inducing a delayed-type hypersensitivity. In the study described in this paper, the model was further refined, and used, in two independent laboratories, to screen 23 low molecular weight compounds of known classification for their allergenicity. Each laboratory was able to accurately detect the contact allergens, despite small variations in the protocols used. However, the classification of dermal irritants, which have often been falsely classified as allergens, varied between the two laboratories. Despite the current limitations of the HOSEC model, the accuracy of the predictions made (sensitiser or non-sensitiser) compare favourably with classifications obtained with commonly used animal models. The HOSEC model has the potential to be developed further as an in vitro alternative to animal models for screening for contact allergens.

Correlation of c-erbB-2 and S-100 expression with the malignancy grading and anatomical site in oral squamous cell carcinoma

An immunohistochemical analysis of 32 cases of oral squamous cell carcinoma (eight in the inferior lip, eight in the lateral angle of the tongue, eight in the palate and eight in the mouth floor) was performed to evaluate the expression pattern of c-erbB-2 protein and S-100-positive cells in the lesions. The immunohistochemical expression was correlated with the tumour anatomical site and histological grading of malignancy. A higher frequency of c-erbB-2-positive cases was found in the tongue, even though no correlation could be detected between the protein expression and the tumour histological grading. With respect to the S-100-positive cells, it was observed that a quantitative decrease was present in the cases classified as high-grade tumours when compared to the low ones (P = 0.0007). Thus, c-erbB-2 immunohistochemical expression is correlated with anatomical localization, and the expression of the S-100 Langerhans' cell markers is decreased significantly in high-grade carcinomas.

Cholesteatoma epithelium is characterized by increased expression of Ki-67, p53 and p21, with minimal apoptosis

OBJECTIVE

To investigate differences in cell proliferation, cell cycle arrest and apoptosis between cholesteatoma and control skin.

MATERIAL AND METHODS

Immunohistochemical sections of 15 cholesteatoma and 15 paired control retro-auricular skin samples were examined for Ki-67, p53, p21 and active caspase 3, using image analysis, as well as for DNA fragmentation.

RESULTS

The retro-auricular skin samples contained 5.7% +/- 3.6%, Ki-67-positive cells and showed a normal expression pattern. In the cholesteatoma epithelium 11.7% +/- 9.5% of the cells were Ki-67-positive and these cells were dominantly expressed in the basal and parabasal cell layers. Retro-auricular skin contained 5.8% +/- 5.4% p53-positive cells and 1.0% +/- 0.9%, p21-positive cells. In the cholesteatoma epithelium 17.8% +/- 12.3% of the cells were p53-positive and 14.3% +/- 11.6% were p21-positive The expression of Ki-67, p53 and p21 differed significantly between the two groups (p < 0.05). In the cholesteatoma epithelium a positive correlation was found between p53 and p21 expression (p = 0.016). Active caspase 3 positivity and DNA fragmentation were rarely seen in the cholesteatoma epithelium.

CONCLUSION

Our results indicate that increased cell proliferation in cholesteatoma epithelium is accompanied by an increase in p53 and p21 protein levels, whilst apoptosis is minimal.

Follow-up to the ECVAM prevalidation study on in vitro tests for acute skin irritation. The European Centre for the Validation of Alternative Methods Skin Irritation Task Force report 2

The European Centre for the Validation of Alternative Methods (ECVAM) Skin Irritation Task Force was established in 1996, to review the status of the development and validation of alternative tests for skin irritation and corrosion, and to identify appropriate non-animal tests for predicting human skin irritation that were sufficiently well-developed to be prevalidated and validated by ECVAM. The EpiDerm method, based on a reconstituted human skin model, was proposed as being sufficiently well advanced to enter a prevalidation (PV) study. Based on a review of test protocols, prediction models (PMs), and data submitted by test developers on ten specified chemicals, with 20% sodium lauryl sulphate as a reference standard, the task force recommended the inclusion of four other tests: EPISKIN and PREDISKIN, based on reconstituted human epidermis or on human skin; the non-perfused pig-ear test, based on pig skin; and the skin integrity function test (SIFT), with ex vivo mouse skin. The prevalidation study on these methods was funded by ECVAM, and took place during 1999-2000. The outcome of the PV study was that none of the methods was ready to enter a formal validation study, and that the protocols and PMs of the methods had to be improved in order to increase their predictive abilities. Improved protocols and PMs for the EpiDerm and EPISKIN methods, the pig ear test, and the SIFT were presented at an extended Task Force meeting held in May 2001. It was agreed that, in the short term, the performance of the revised and harmonised EpiDerm and EPISKIN methods, as well as the modified SIFT, should be evaluated in a further study with a new set of 20 test chemicals. In addition, it was decided that the SIFT and the pig ear test would be compared to see if common endpoints (transepidermal water loss, methyl green-pyronine stain) could be identified.