Profound Defect of Amphiregulin Secretion by Regulatory T Cells in the Gut of HIV-Treated Patients

The persistence of a leaky gut in HIV-treated patients leads to chronic inflammation with increased rates of cardiovascular, liver, kidney, and neurological diseases. Tissue regulatory T (tTreg) cells are involved in the maintenance of intestinal homeostasis and wound repair through the IL-33 pathway. In this study, we investigated whether the persistence of gut mucosal injury during HIV infection might be explained in part by a flaw in the mechanisms involved in tissue repair. We observed an increased level of IL-33 in the gut of HIV-infected patients, which is associated with an increased level of fibrosis and a low peripheral reconstitution of CD4⁺ T cells. Our results showed that intestinal Treg cells from HIV-infected patients were enriched in tTreg cells prone to support tissue repair. However, we observed a functional defect in tTreg cells caused by the lack of amphiregulin secretion, which could contribute to the maintenance of intestinal damage. Our data suggest a mechanism by which the lack of amphiregulin secretion by tTreg may contribute to the lack of repair of the epithelial barrier.

Hair follicle stem cell replication stress drives IFI16/STING-dependent inflammation in hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, relapsing, inflammatory skin disease. HS appears to be a primary abnormality in the pilosebaceous-apocrine unit. In this work, we characterized hair follicle stem cells (HFSCs) isolated from HS patients and more precisely the outer root sheath cells (ORSCs). We showed that hair follicle cells from HS patients had an increased number of proliferating progenitor cells and lost quiescent stem cells. Remarkably, we also showed that the progression of replication forks was altered in ORSCs from hair follicles of HS patients, leading to activation of the ATR/CHK1 pathway. These alterations were associated with an increased number of micronuclei and with the presence of cytoplasmic ssDNA, leading to the activation of the IFI16/STING pathway and the production of type I IFNs. This mechanistic analysis of the etiology of HS in the HFSC compartment establishes a formal link between genetic predisposition and skin inflammation observed in HS.

The value of five blood markers in differentiating mycosis fungoides and Sézary syndrome: a validation cohort

BACKGROUND

Clinical and histological diagnosis of Sézary syndrome (SS) and mycosis fungoides (MF) is challenging in clinical routine.

OBJECTIVES

We investigated five blood markers previously described for SS (T-plastin, Twist, KIR3DL2, NKp46 and Tox) in a prospective validation cohort of patients.

METHODS

We included 447 patients in this study and 107 patients were followed up for prognosis. The markers were analysed by reverse transcriptase quantitative real-time polymerase chain reaction (RT-qPCR) on peripheral blood leucocytes and CD4⁺ T cells in a cohort of consecutive patients with early MF, erythrodermic MF and SS and compared with patients presenting with benign inflammatory dermatoses (BID) and erythrodermic BID. The markers were assessed in parallel to gold standard values such as CD4/CD8 ratio, loss of CD7 and CD26 membrane expression and CD4 absolute values. Sensitivity and specificity were analysed by receiver operator characteristic curves. The prognostic value of selected markers was analysed on a subset of patients. This study was conducted in one centre.

RESULTS

We defined cut-off values for each marker. T-plastin, Twist and KIR3DL2 had the best validity. SS may be overrepresented. The combination of T-plastin and Twist was able to differentiate between erythrodermic MF or BID and SS. The additional analysis of KIR3DL2 may be useful to predict the prognosis.

CONCLUSIONS

We propose T-plastin, Twist and KIR3DL2 measured by RT-qPCR as new diagnostic markers for Sézary syndrome.

Photobiomodulation therapy promotes in vitro wound healing in nicastrin KO HaCaT cells

Mutations in NCSTN gene (encoding for nicastrin protein) are associated with hidradenitis suppurativa (HS), a chronic inflammatory disease involving hair follicles. HS is clinically handled with drugs but the most severe cases are treated with surgery. Photobiomodulation (PBM) therapy, already used in the treatment of skin diseases such as acne, herpes virus lesions, ultraviolet damage, vitiligo, hypertrophic scar, keloid, burn, psoriasis and diabetic chronic wounds, could be beneficial as an adjuvant supportive treatment to promote and foster the healing process after skin excision in HS. The effects of PBM therapy in promoting the wound closure are evaluated in a HaCaT cells NCSTN-/-, assessing cell metabolism, migration rate, proliferation and cell cycle progression. In our experimental model, PBM exerts a potent action on metabolism of mutated keratinocytes, incrementing adenosine triphosphate (ATP) production at 2 hours, while after 24 hours an increase of metabolism with a decrement of intracellular ATP levels were recorded. Moreover, PBM speeds up the wound closure, inducing cells' migration without affecting their proliferation.Based on our findings, we suggest the use of PBM in HS patients, who undergo major surgery with large skin excision.

Study of gene expression alteration in male androgenetic alopecia: evidence of predominant molecular signalling pathways

BACKGROUND

Male androgenetic alopecia (AGA) is the most common form of hair loss in men. It is characterized by a distinct pattern of progressive hair loss starting from the frontal area and the vertex of the scalp. Although several genetic risk loci have been identified, relevant genes for AGA remain to be defined.

OBJECTIVES

To identify biomarkers associated with AGA.

METHODS

Molecular biomarkers associated with premature AGA were identified through gene expression analysis using cDNA generated from scalp vertex biopsies of hairless or bald men with premature AGA, and healthy volunteers.

RESULTS

This monocentric study reveals that genes encoding mast cell granule enzymes, inflammatory mediators and immunoglobulin-associated immune mediators were significantly overexpressed in AGA. In contrast, underexpressed genes appear to be associated with the Wnt/β-catenin and bone morphogenic protein/transforming growth factor-β signalling pathways. Although involvement of these pathways in hair follicle regeneration is well described, functional interpretation of the transcriptomic data highlights different events that account for their inhibition. In particular, one of these events depends on the dysregulated expression of proopiomelanocortin, as confirmed by polymerase chain reaction and immunohistochemistry. In addition, lower expression of CYP27B1 in patients with AGA supports the notion that changes in vitamin D metabolism contributes to hair loss.

CONCLUSIONS

This study provides compelling evidence for distinct molecular events contributing to alopecia that may pave the way for new therapeutic approaches.

Intrinsic Defect in Keratinocyte Function Leads to Inflammation in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory, debilitating, follicular disease of the skin. Despite a high prevalence in the general population, the physiopathology of HS remains poorly understood. The use of antibiotics and immunosuppressive agents for therapy suggests a deregulated immune response to microflora. Using cellular and gene expression analyses, we found an increased number of infiltrating CD4(+) T cells secreting IL-17 and IFN-γ in perilesional and lesional skin of patients with HS. By contrast, IL-22-secreting CD4(+) T cells are not enriched in HS lesions contrasting with increased number of those cells in the blood of patients with HS. We showed that keratinocytes isolated from hair follicles of patients with HS secreted significantly more IL-1β, IP-10, and chemokine (C-C motif) ligand 5 (RANTES) either constitutively or on pattern recognition receptor stimulations. In addition, they displayed a distinct pattern of antimicrobial peptide production. These findings point out a functional defect of keratinocytes in HS leading to a balance prone to inflammatory responses. This is likely to favor a permissive environment for bacterial infections and chronic inflammation characterizing clinical outcomes in patients with HS.

Human lung fibroblasts may modulate dendritic cell phenotype and function: results from a pilot in vitro study

In human lung fibrotic lesions, fibroblasts were shown to be closely associated with immature dendritic cell (DC) accumulation. The aim of the present pilot study was to characterize the role of pulmonary fibroblasts on DC phenotype and function, using co-culture of lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) and from control patients, with a DC cell line MUTZ-3. We observed that co-culture of lung control and IPF fibroblasts with DCs reduced the expression of specific DC markers and down-regulated their T-cell stimulatory activity. This suggests that pulmonary fibroblasts might sustain chronic inflammation in the fibrotic lung by maintaining in situ a pool of immature DCs.

Transforming growth factor-β increases interleukin-13 synthesis via GATA-3 transcription factor in T-lymphocytes from patients with systemic sclerosis

Introduction

Transforming growth factor (TGF)-β and interleukin (IL)-13 play a crucial role in the pathogenesis of systemic sclerosis (SSc), partly through activation of collagen production that leads to fibrosis. The aim of the present study was to determine whether TFG-β alters IL-13 production in T lymphocytes from patients with SSc from that seen in those of healthy donors.

Methods

IL-13 mRNA and protein synthesis under TFG-β exposure was measured in circulating T lymphocytes from healthy donors and patients with SSc and also in the Jurkat Th2 T-cell line, using quantitative real-time PCR and fluorescence-activated cell sorting analysis, respectively. The involvement of Smad and GATA-3 transcription factors was assessed by using specific inhibitors and small interfering RNA, and the binding capacity of GATA-3 to the IL-13 gene promoter was evaluated by chromatin immunoprecipitation assay.

Results

TGF-β induced a significant decrease in IL-13 mRNA and protein levels in lymphocytes from healthy donors (mean [±SD] inhibition of 30 % ± 10 % and 20 % ± 7 %, respectively; p < 0.05). In contrast, TGF-β promoted a significant increase in IL-13 mRNA levels and IL-13 synthesis by CD4⁺ and CD8⁺ T-cell subtypes from patients with SSc, with respective increases of 2.4 ± 0.3-fold, 1.6 ± 0.05-fold and 2.7 ± 0.02-fold. The involvement of the Smad signaling pathway and upregulation of GATA-3 binding capacity on the IL-13 promoter in lymphocytes from patients with SSc contributed to the effect of TGF-β on IL-13 production.

Conclusions

These results demonstrate that TGF-β upregulates IL-13 synthesis through GATA-3 expression in the T lymphocytes of patients with SSc, confirming that the GATA-3 transcription factor can be regarded as a novel therapeutic target in patients with SSc.

T-plastin expression downstream to the calcineurin/NFAT pathway is involved in keratinocyte migration

Cutaneous wound healing requires keratinocyte proliferation, migration and differentiation to restore the barrier function of the skin. The calcineurin/nuclear factor of activated-T-cell (NFAT) signaling pathway has been recently shown to be involved in keratinocyte growth, differentiation and migration. It is induced by an increased intracellular calcium rate and its inhibition results in decreased capacities of keratinocytes to migrate. Nevertheless, the link between calcineurin activation and keratinocyte migration remains unknown. Recently, Orai1, a pore subunit of a store-operated calcium channel that favors calcium influx, was shown to play a critical role to control proliferation and migration of basal keratinocytes. Of interest, the actin-bundling T-plastin is crucial in cell motility through cross-linking to actin filament and its synthesis was shown to be induced by calcium influx and regulated by the calcineurin/NFAT pathway in tumor Sezary cells. We investigated herein the role of the calcineurin/NFAT pathway-dependent T-plastin in keratinocyte migration, by quantifying T-plastin expression in keratinocytes and by analyzing their migration under calcineurin inhibition or knockdown of NFAT2 or T-plastin. We did confirm the role of the calcineurin/NFAT pathway in keratinocyte migration as shown by their decreased capacities to migrate after FK506 treatment or siNFAT2 transfection in both scratching and Boyden assays. The expression of NFAT2 and T-plastin in keratinocytes was decreased under FK506 treatment, suggesting that T-plastin plays a role in keratinocyte migration downstream to the calcineurin/NFAT pathway. Accordingly, siRNA knockdown of T-plastin expression also decreased their migration capacities. Actin lamellipodia formation as well as FAK and β6-integrin expression were also significantly decreased after treatment with FK506 or siRNA, reinforcing that NFAT2-dependent T-plastin expression plays a role in keratinocyte migration. These results indicate that T-plastin might be considered as a major actor in the mechanisms underlying calcineurin/NFAT-dependent keratinocyte migration and may explain wound-healing defects observed in patients under calcineurin inhibitor long-term treatment.

Expression of transforming growth factor β receptor II in mesenchymal stem cells from systemic sclerosis patients

OBJECTIVES

The present work aimed to evaluate the expression of transforming growth factor-β (TGF-β) receptors on bone marrow-derived multipotent mesenchymal stromal cells (MSCs) in patients with systemic sclerosis (SSc) and the consequences of TGF-β activation in these cells, since MSC have potential therapeutic interest for SSc patients and knowing that TGF-β plays a critical role during the development of fibrosis in SSc.

DESIGN

This is a prospective research study using MSC samples obtained from SSc patients and compared with MSC from healthy donors.

SETTING

One medical hospital involving collaboration between an internal medicine department for initial patient recruitment, a clinical biotherapeutic unit for MSC preparation and an academic laboratory for research.

PARTICIPANTS

9 patients with diffuse SSc for which bone marrow (BM) aspiration was prescribed by sternum aspiration before haematopoietic stem cell transplantation, versus nine healthy donors for normal BM.

PRIMARY AND SECONDARY OUTCOME MEASURES

TGF-β, TGF-β receptor types I (TBRI) and II (TBRII) mRNA and protein expression were assessed by quantitative PCR and flow cytometry, respectively, in MSC from both SSc patients and healthy donors. MSC were exposed to TGF-β and assessed for collagen 1α2 synthesis and Smad expression. As positive controls, primary cultures of dermal fibroblasts were also analysed.

RESULTS

Compared with nine controls, MSC from nine SSc patients showed significant increase in mRNA levels (p<0.002) and in membrane expression (p<0.0001) of TBRII. In response to TGF-β activation, a significant increase in collagen 1α synthesis (p<0.05) and Smad-3 phosphorylation was upregulated in SSc MSC. Similar results were obtained on eight SSc-derived dermal fibroblasts compared to six healthy controls.

CONCLUSIONS

TBRII gene and protein expression defect in MSC derived from SSc patients may have pathological significance. These findings should be taken into account when considering the use of MSC-based therapies in an autologous setting.

Down-regulating constitutive activation of the NF-κB canonical pathway overcomes the resistance of cutaneous T-cell lymphoma to apoptosis

Constitutive activation of the nuclear factor-kappaB (NF-κB) pathway has been shown to be involved in the resistance of tumor cells to apoptosis in several human malignancies of the hematopoietic lineage. By using electrophoretic mobility shift assay (EMSA) and confocal microscopic analysis, we demonstrate that NF-κB is constitutively activated in cutaneous T-cell lymphoma (CTCL) cell lines HuT-78, MyLa, and SeAx and in peripheral blood lymphocytes (PBLs) from patients with Sézary syndrome (SS) presenting a high ratio of tumor cells, with evidence of p50 and RelA/p65 in DNA-linked complexes. Transfection of SeAx line with a κB/luciferase reporter plasmid showed that translocated NF-κB complexes were functional. Selective inhibition of NF-κB, by transfecting CTCL cell lines with a super-repressor form of IκBα, led to apoptosis. We evidenced down-regulation of NF-κB activation and induction of CTCL cell apoptosis in the presence of proteasome 26S inhibitors ALLN, MG132, and bortezomib. Bortezomib at nanomolar concentrations inhibited constitutive activation of NF-κB and induced apoptosis of CTCL cells, with evidence of an upregulation of Bax expression. These results demonstrate the key role played by NF-κB in the resistance of CTCL to apoptosis and suggest that bortezomib might be useful for the treatment of patients with advanced stages of CTCL refractory to standard antineoplastic chemotherapy.

Arsenic trioxide induces apoptosis of cutaneous T cell lymphoma cells: evidence for a partially caspase-independent pathway and potentiation by ascorbic acid (vitamin C)

Arsenic trioxide (As2O3) displays apoptogenic properties against various types of hematopoietic malignancies. We investigated the effects of As2O3 on the viability of the cutaneous T cell lymphoma cell lines HuT-78, SeAx, and Myla, and of peripheral blood mononuclear cells from patients with Sézary syndrome, by using propidium iodide and annexin-V staining, terminal deoxyuridine triphosphate nick end labeling (TUNEL), cell cycle analysis, mitochondrial transmembrane potential (delta psi(m)) alterations, cytochrome c release, and detection of processed caspase-3. We also report in vivo effects of As2O3 in two patients with cutaneous T cell lymphoma. The results show that As2O3 induces apoptosis of cutaneous T cell lymphoma lines and of Sézary cells from patients in a time- and concentration-dependent manner in vitro, as demonstrated by annexin-V staining, mitochondrial depolarization, and DNA fragmentation. Ascorbic acid 100 microM potentiated As2O3-induced Sézary cell death, whereas interferon-alpha had no synergistic effect. As2O3-induced Sézary cell death involves activation of caspase-3, cleavage of poly(ADP-ribose)polymerase, and cytochrome c release, but was only partially inhibited by the pancaspase inhibitor Z-VAD.fluoromethylketone. Finally, As2O3 was administered to two patients with cutaneous T cell lymphoma, allowing us to obtain a partial response in one case, whereas stability was observed in the second patient. These results demonstrate that As2O3 synergizes with ascorbic acid to induce Sézary cell death at clinically achievable concentrations, through a caspase-partially independent pathway, and provide a rationale for further in vivo studies addressing the therapeutic efficacy of As2O3 in cutaneous T cell lymphoma patients.

Imperforate hymen: congenital or acquired from sexual abuse?

Imperforate hymen diagnosed beyond the newborn period may present a dilemma for the physician. Three case studies are reviewed in which children with the diagnoses of imperforate hymen presented for evaluation of suspected sexual abuse. Clear descriptions of genital anatomy documented at well-child visits may be critical to later interpretations of findings encountered during examinations for suspected sexual abuse.

Humoral and cellular responses to histamine and pollen allergen in a skin chamber model: effect of mizolastine

BACKGROUND

Mizolastine is a new non-sedative antihistamine and antiallergic drug proven to be effective and safe in the treatment of allergic rhinitis and urticaria.

OBJECTIVE

To quantitatively explore the time course of mediator release and cell recruitment during allergen challenge and the effects of mizolastine on the event, using the skin chamber model.

METHODS

Twelve pollen-sensitive patients (23+/-6 years) were included in a double-blind crossover study. Patients received 10 mg mizolastine or placebo once daily in the first 4-day period and, after a 3-week washout period, vice-versa in the crossover period. On day 4 of each period, a non-invasive in vivo skin chamber technique was used to determine the alteration of vascular permeability, mast cell mediator release, the release of soluble intercellular adhesion molecule -1(sICAM-1) in skin sites challenged with exogenous histamine or grass pollen allergen extract, over an 8-hour period.

RESULTS

Challenge with allergen-induced significant mast cell activation, as indicated by the release of histamine, tryptase and LTC4, in chamber fluids 2 hours after initiation of the allergic reaction and during the following 6 hours. Both exogenous histamine and allergen induced significant vasodilatation, which was sustained during the 8-hour challenge, as indicated by the accumulation of protein in the chamber fluids. Likewise, both histamine and allergen induced the release of significant amounts of ICAM-1 throughout the 8-hour period. Mizolastine significantly inhibited the histamine- and allergen-induced extravasation (after 2 hours, P = .003; after 8 hours, P = .009; after 2 hours, P = .044; after 8 hours, P = .003 respectively) and the histamine- and allergen-induced--ICAM-1 release (after 2 hours, P = .004; after 8 hours, P = .05; after 2 hours, P = .03 respectively).

CONCLUSION

Mizolastine strongly inhibited the local response to histamine in this skin chamber model with, of interest, inhibition of the release of the soluble adhesion-molecule ICAM-1.

Ophthalmomyiasis and nasal myiasis in New Zealand: a case series

We report three cases of ophthalmomyiasis in New Zealand, due to the larvae of Oestrus ovis. All three patients reported eye injury caused by a fly. The larvae were removed from the conjunctival sac without difficulty under local anaesthesia. Presenting ocular symptoms of foreign body sensation, irritation, redness and photophobia all resolved swiftly. Topical antibiotic and steroid eye drops were administered. All three patients also developed nasal symptoms such as sneezing, nasal discharge and epistaxis. Otolaryngology follow-up demonstrated nasal myiasis in two patients which was treated with nasal decongestants. In addition, all three patients were treated with ivermectin (Mectizan).

Sudden infant death syndrome, child sexual abuse, and child development

Since the introduction of the Back to Sleep Campaigns, there has been a dramatic reduction in sudden infant death syndrome in this country. Steven Blatt and Victoria Meguid review the literature surrounding sleep position. Investigators have continued efforts to find other modifiable risk factors of sudden infant death syndrome. A prospective study of more than 33,000 neonates found a link between a prolonged QT electrocardiogram interval and sudden infant death syndrome. Also discussed are investigations seeking to explain the relationship between smoking and sudden infant death syndrome. Ann Botash, Florence Jean-Louis and Mongkae Ploy Siripornsawan review the latest thinking on genital warts and their relation to specific viral etiologies and child sexual abuse. Other symptoms and signs of sexual abuse are the focus of a number of articles that can help the practitioner care for these unfortunate children. Catherine Church reviews medication options for children diagnosed with pervasive developmental disorders or autism spectrum disorders. Finally, in this article, risperidone, fluoxetine and naltrexone are reviewed.

Production, metabolism and effect of platelet-activating factor on the growth of the human K562 erythroid cell line

The human immature K562 erythroid cell line was studied for its capacity to produce and to metabolize the phospholipid molecule platelet-activating factor (PAF). K562 cells produced PAF under calcium ionophore stimulation. Lyso PAF and acetyl-CoA (the acetate donor molecule for the acetylation of lyso PAF into PAF) had no effect on the amounts of PAF produced by ionophore-stimulated cells. The metabolism of PAF and lyso PAF by K562 cells was compared to that of freshly-isolated human bone marrow erythroblasts and blood erythrocytes. K562 cells rapidly metabolized [3H]PAF and [3H]lyso PAF with 1-alkyl analogue of phosphatidylcholine as the major metabolic product. In contrast, blood erythrocytes did not. PAF acetylhydrolase activity levels in K562 cells and bone marrow erythroblasts were similar and higher than in blood erythrocytes. PAF (1-100 nM) stimulated [3H]thymidine incorporation in K562 cells grown in low serum concentration, a non-metabolizable PAF agonist being more potent than PAF to stimulate thymidine incorporation. PAF receptor mRNA was detected in K562 cells by polymerase chain reaction on reverse transcripts. The present study demonstrates that K562 cells produce and metabolize PAF and underlines the putative role of erythroid precursors in the modulation of bone marrow PAF concentrations. The effect of PAF on the growth of K562 cells might be mediated through PAF receptors suggesting a potential role of PAF on the proliferation and functions of human erythroid marrow precursors.

Acquisition of granzyme B and Fas ligand proteins by human keratinocytes contributes to epidermal cell defense

In vertebrate tissues, cell integrity is maintained by at least three mechanisms. During an immune response, injured cells are eliminated by cytotoxic lymphoid cells that produce perforin, granzyme B, and Fas ligand (FasL). Second, epithelial cells can produce FasL as an immunosuppressive protein, probably to protect the tissue against immune-mediated damage. Third, locally secreted antimicrobial peptides can be operative in the protection of animal and human epithelia. In this work, as another contribution to local mechanisms of host defense, the ability of human epidermal keratinocytes to produce cytotoxic proteins was investigated. To address this question, freshly isolated human epidermal cells and keratinocytes grown in vitro were studied. Freshly isolated epidermal cells did not express the cytolytic proteins. In contrast, keratinocyte growth to confluence was associated with granzyme B, perforin, and FasL mRNA and protein synthesis. These proteins were secreted in the culture medium. Further analysis showed that they were identical with the ones used by cytotoxic lymphocytes. Their function was then investigated with a view to a potential role in epidermal cell integrity. The data showed that activated human keratinocytes were able to protect against invading pathogens through granzyme B expression. This was demonstrated by the ability of granzyme B to greatly decrease the bacterial growth of Staphylococcus epidermidis. In addition, keratinocytes expressing FasL were found to prevent immune epidermal cell damage. Apoptosis of Fas-sensitive T cells occurred during coculture with confluent epidermal keratinocytes and was largely reduced by the addition of a FasL inhibitor. The data favor keratinocyte involvement in the regulation of dermal inflammatory responses.

Acquisition of granzyme B and Fas ligand proteins by human keratinocytes contributes to epidermal cell defense

In vertebrate tissues, cell integrity is maintained by at least three mechanisms. During an immune response, injured cells are eliminated by cytotoxic lymphoid cells that produce perforin, granzyme B, and Fas ligand (FasL). Second, epithelial cells can produce FasL as an immunosuppressive protein, probably to protect the tissue against immune-mediated damage. Third, locally secreted antimicrobial peptides can be operative in the protection of animal and human epithelia. In this work, as another contribution to local mechanisms of host defense, the ability of human epidermal keratinocytes to produce cytotoxic proteins was investigated. To address this question, freshly isolated human epidermal cells and keratinocytes grown in vitro were studied. Freshly isolated epidermal cells did not express the cytolytic proteins. In contrast, keratinocyte growth to confluence was associated with granzyme B, perforin, and FasL mRNA and protein synthesis. These proteins were secreted in the culture medium. Further analysis showed that they were identical with the ones used by cytotoxic lymphocytes. Their function was then investigated with a view to a potential role in epidermal cell integrity. The data showed that activated human keratinocytes were able to protect against invading pathogens through granzyme B expression. This was demonstrated by the ability of granzyme B to greatly decrease the bacterial growth of Staphylococcus epidermidis. In addition, keratinocytes expressing FasL were found to prevent immune epidermal cell damage. Apoptosis of Fas-sensitive T cells occurred during coculture with confluent epidermal keratinocytes and was largely reduced by the addition of a FasL inhibitor. The data favor keratinocyte involvement in the regulation of dermal inflammatory responses.

Heparin induces fibroblast proliferation, cell-matrix interaction and epidermal growth inhibition

We have examined the effect of heparin on fibroblasts cultivated in monolayer or in a 3-dimensional culture system: the so-called collagen lattices. Thereafter, we have investigated the effect of heparin on the kinetics of epidermal growth on the collagen lattices. In monolayer culture, heparin stimulated the fibroblast growth with an optimal response at 0.01 mg/ml. The volume of treated fibroblasts was smaller than that of untreated controls. In the collagen lattices, heparin stimulated the fibroblast growth with an optimal response at 0.1 mg/ml. The volume of treated fibroblasts was greater than that of untreated controls, the opposite to the result observed in monolayer culture. The beginning of the contraction of the collagen lattices was inhibited by heparin. Heparin inhibited epidermal growth on the immersion as well as on the emersion collagen lattices. These effects of heparin should be the consequences of heparin-induced modifications of cell-matrix interactions.

Effect of human basic fibroblast growth factor on fibroblast proliferation, cell volume, collagen lattice contraction: in comparison with acidic type

Human recombinant basic fibroblast growth factor (bFGF) is a potent mitogen for normal human dermal fibroblasts in the presence of heparin which binds to and stabilizes it. The optimal mitotic response is obtained with a concentration of 1 ng/ml of bFGF in monolayer cultures (non-differentiated fibroblasts) as well as in the better-differentiated fibroblasts obtained through the 'collagen lattices' culture system (fibroblasts embedded in a 3-dimensional collagen gel) achieving a doubling of the cell number in 8 days. Despite increasing the number of cells, bFGF decreases the ability of fibroblasts to contract collagen fibers. This inhibition is concentration-dependent and reaches a plateau at a dose of about 1 ng/ml. This effect is associated with a bFGF-induced decrease of fibroblast volume. Various dosing regimens indicate that although the highest response was obtained by daily dosing nearly optimal response was obtained either by early daily dosing or short intermittent treatment. Interestingly, the fibroblast mitotic response to bFGF decreases steadily when fibroblasts mature in collagen gels. The mitogenic properties of bFGF associated to its ability to inhibit fibroblasts contraction, if demonstrated in vivo, may be of interest in the management of wound healing.

Production of paf-acether by human epidermal cells

The production of the inflammatory mediator paf-acether (paf) from human epidermal cells was investigated in vitro. Human epidermal cells, freshly isolated from normal skin or in culture, were incubated in Tyrode's buffer containing 0.25% lipid-free bovine serum albumin in the presence of 2 microM calcium ionophore A23187, at 37 degrees C, for 1 to 60 min. Paf production slightly began at the first min of stimulation, was significant after 10 min, reached a maximum at 20 min (251 +/- 25 pg/l X 10(6) cells, mean +/- 1 SD), and decreased thereafter. About 50% of the paf amount produced by epidermal cells was recovered in supernatants. Addition of the non-acetylated paf precursor 1-O-octadecyl-sn-glycero-3-phosphocholine, i.e., lyso-paf, at 0.1 microM to epidermal cells during A23187-stimulation did not alter this production. In contrast, addition of acetyl-coenzyme A at 0.1 mM enhanced paf production by 5 times. The material produced by epidermal cells was identical to synthetic paf because: 1) the aggregation of aspirin-treated and ADP-insensitive washed rabbit platelets it induced was inhibited by BN 52021, an antagonist of the paf putative receptor; 2) the factor was inactivated by phospholipase A2 but was insensitive to lipase from Rhizopus arrhizus; 3) it exhibited the same retention time as synthetic paf during standard and reverse-phase (RP) high-pressure liquid chromatography (HPLC) elution. The paf precursors, i.e., lyso-paf and 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine, were also detected in epidermal cells, stimulated with A23187 or not. As determined by RP-HPLC analysis and confirmed by gas chromatography analysis, these precursors and the paf produced by epidermal cells exhibited more than 90% of a hexadecyl chain at the sn-1 position of the molecule. The present results demonstrate the synthesis and release of paf by normal human epidermal cells. Paf production within the epidermis might account for the development of cutaneous inflammation and the pathogenesis of many skin disorders.

Biological and cellular responses to grass pollen in sensitive patients

Using a noninvasive skin chamber technique, we studied the in vivo development of anaphylactic reactions in 8 pollen-sensitive patients suffering from seasonal allergic rhinitis/conjunctivitis/asthma and showing positive cutaneous reactions after intradermal allergen challenge. As agonists, histamine and pollen were introduced into the skin chambers and left in contact with superficial dermis during 6 h. The release of mediators (histamine and prostaglandin [PG] D2) and the modifications in protein diffusion occurring during the immediate (30 min) and the late (6 and 24 h) cutaneous reaction phases were quantitatively analyzed. 24 h after agonist introduction, the recruitment of inflammatory cells on the superficial dermis was studied by use of Rebuck's windows. Histamine release in pollen-containing skin chambers was immediate and persisted until the 24th h despite replacement of the agonists by control medium at the 6th h. An intense PGD2 release occurred as soon as the first 30 min in chambers containing either exogenous histamine or pollen and was maintained until the 24th h. Protein diffusion induced by histamine and pollen was similar to the control one at 30 min but was intensely enhanced at the 6th h. At the 24th h, pollen-induced protein diffusion was still intense whereas that induced by histamine was analogous to the control one. 24 h after pollen challenge, numerous eosinophils were recruited on the superficial dermis but almost none were observed after control medium or histamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Biosynthesis of paf-acether factor-acether by human skin fibroblasts in vitro

The synthesis and release of paf-acether by fibroblasts from normal human skin was investigated in vitro. When fibroblasts in suspension (1 X 10(6) cells) were stimulated with 2 microM Ca1+ ionophore A23187 (Io), they synthesized a material that aggregated aspirin-treated washed rabbit platelets and was identified as paf because 1) the platelet aggregation it induced was inhibited by BN 52021, an antagonist of paf putative receptors; 2) the factor was inactivated by phospholipase A2 but was insensitive to lipase from Rhizopus arrhizus; 3) it exhibited the same retention time as synthetic paf during standard and reverse phase HPLC elution. Paf production by fibroblasts occurred as soon as the first min of Io stimulation (287 +/- 92 pg/1 X 10(6) cells), reached a maximum at 5 min (369 +/- 85 pg/1 X 10(6) cells) and decreased thereafter. Half of the fibroblast-produced paf was recovered in supernatants. Addition of exogenous 1-O-alkyl-sn-glycero-3-phosphocholine (lyso-paf) at 0.1 microM and/or acetyl-coenzyme A at 0.1 mM to fibroblasts during Io stimulation enhanced paf production by two- and three-fold, respectively. The paf precursors, i.e., 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine (1-alkyl-2-acyl-GPC) and lyso-paf, were detected in fibroblasts either stimulated with Io or not. These precursors exhibited 80% hexadecyl and 20% octadecyl chains at the sn-1 position of the molecules, as determined by reverse phase HPLC and gas chromatography analysis. The present results are the first to demonstrate the synthesis and release of paf by fibroblasts from normal human skin. Such production within the dermis might account for the development of cutaneous inflammation and for the pathogenesis of many skin disorders.

Biosynthesis of paf-acether factor-acether by human skin fibroblasts in vitro

The synthesis and release of paf-acether by fibroblasts from normal human skin was investigated in vitro. When fibroblasts in suspension (1 X 10(6) cells) were stimulated with 2 microM Ca1+ ionophore A23187 (Io), they synthesized a material that aggregated aspirin-treated washed rabbit platelets and was identified as paf because 1) the platelet aggregation it induced was inhibited by BN 52021, an antagonist of paf putative receptors; 2) the factor was inactivated by phospholipase A2 but was insensitive to lipase from Rhizopus arrhizus; 3) it exhibited the same retention time as synthetic paf during standard and reverse phase HPLC elution. Paf production by fibroblasts occurred as soon as the first min of Io stimulation (287 +/- 92 pg/1 X 10(6) cells), reached a maximum at 5 min (369 +/- 85 pg/1 X 10(6) cells) and decreased thereafter. Half of the fibroblast-produced paf was recovered in supernatants. Addition of exogenous 1-O-alkyl-sn-glycero-3-phosphocholine (lyso-paf) at 0.1 microM and/or acetyl-coenzyme A at 0.1 mM to fibroblasts during Io stimulation enhanced paf production by two- and three-fold, respectively. The paf precursors, i.e., 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine (1-alkyl-2-acyl-GPC) and lyso-paf, were detected in fibroblasts either stimulated with Io or not. These precursors exhibited 80% hexadecyl and 20% octadecyl chains at the sn-1 position of the molecules, as determined by reverse phase HPLC and gas chromatography analysis. The present results are the first to demonstrate the synthesis and release of paf by fibroblasts from normal human skin. Such production within the dermis might account for the development of cutaneous inflammation and for the pathogenesis of many skin disorders.

Late ear sequelae in cleft palate patients

This retrospective study looks at the incidence and nature of ear disease in 50 adolescent patients who had cleft palates repaired in infancy. Half of these patients had a history of grommet insertion. We found that most patients had normal hearing (81%) and middle-ear pressures (86%), although about half had tympanic membrane abnormalities. Grommet insertion did not result in better long-term hearing in this study but was strongly associated with tympanosclerosis. Cleft type did not influence the degree of ear disease although more patients with complete clefts had a history of repeated grommet insertion. Otitis media with effusion is almost universal in cleft palate infants and may influence later language, speech and educational development. At the time of palatal repair grommets should be inserted to improve hearing in these infants.