Immunohistopathological characterization and the impact of topical immunomodulatory therapy in oral chronic graft-versus-host disease: A pilot study.

OBJECTIVE: To characterize the immunohistopathological features of oral chronic graft-versus-host disease (cGVHD), and the impact of topical immunomodulatory therapy on the infiltrating cells. MATERIAL AND METHODS: Paired oral cGVHD biopsies obtained before (n = 12) and 1 month after treatment (n = 12) with topical dexamethasone (n = 8) or tacrolimus (n = 4) were characterized by immunohistochemistry using a panel of CD1a, CD3, CD4, CD8, CD20, CD31, CD62E, CD103, CD163, c-kit, and FoxP3. Controls included acute GVHD (aGVHD; n = 3), oral lichen planus (OLP; n = 5), and normal tissues (n = 5). RESULTS: Oral cGVHD specimens prior to treatment were mainly characterized by basal cell squamatization, lichenoid inflammation, sclerosis, apoptosis, and lymphocytic exocytosis. The infiltrating cells in oral cGVHD primarily consisted of CD3+ , CD4+ , CD8+ , CD103+ , CD163+ , and FoxP3+ cells, which were higher than in normal tissues. Topical dexamethasone or tacrolimus reduced neutrophilic exocytosis, basal cell squamatization, and lichenoid inflammation in oral cGVHD, and dexamethasone reduced the number of CD4+ and CD103+ cells. CONCLUSION: The high expression of CD3, CD4, CD8, CD103, CD163, and FoxP3 confirms that oral cGVHD is largely T-cell-driven with macrophage participation. The impact of topical immunomodulatory therapy was variable, reducing histological inflammatory features, but with a weak clinicopathological correlation. Topical dexamethasone reduced the expression of CD4 and CD103, which may offer novel therapeutic targets.

Transformation of Face Transplants: Volumetric and Morphologic Graft Changes Resemble Aging After Facial Allotransplantation.

Facial allotransplantation restores normal anatomy to severely disfigured faces. Although >30 such operations performed worldwide have yielded promising short-term results, data on long-term outcomes remain scarce. Three full-face transplant recipients were followed for 40 months. Severe changes in volume and composition of the facial allografts were noted. Data from computed tomography performed 6, 18 and 36 months after transplantation were processed to separate allograft from recipient tissues and further into bone, fat and nonfat soft tissues. Skin and muscle biopsies underwent diagnostic evaluation. All three facial allografts sustained significant volume loss (mean 19.55%) between 6 and 36 months after transplant. Bone and nonfat soft tissue volumes decreased significantly over time (17.22% between months 6 and 18 and 25.56% between months 6 and 36, respectively), whereas fat did not. Histological evaluations showed atrophy of muscle fibers. Volumetric and morphometric changes in facial allografts have not been reported previously. The transformation of facial allografts in this study resembled aging through volume loss but differed substantially from regular aging. These findings have implications for risk-benefit assessment, donor selection and measures counteracting muscle and bone atrophy. Superior long-term outcomes of facial allotransplantation will be crucial to advance toward future clinical routine.

Codominant Role of Interferon-γ- and Interleukin-17-Producing T Cells During Rejection in Full Facial Transplant Recipients.

Facial transplantation is a life-changing procedure for patients with severe composite facial defects. However, skin is the most immunogenic of all transplants, and better understanding of the immunological processes after facial transplantation is of paramount importance. Here, we describe six patients who underwent full facial transplantation at our institution, with a mean follow-up of 2.7 years. Seum, peripheral blood mononuclear cells, and skin biopsy specimens were collected prospectively, and a detailed characterization of their immune response (51 time points) was performed, defining 47 immune cell subsets, 24 serum cytokines, anti-HLA antibodies, and donor alloreactivity on each sample, producing 4269 data points. In a nonrejecting state, patients had a predominant T helper 2 cell phenotype in the blood. All patients developed at least one episode of acute cellular rejection, which was characterized by increases in interferon-γ/interleukin-17-producing cells in peripheral blood and in the allograft's skin. Serum monocyte chemotactic protein-1 level was significantly increased during rejection compared with prerejection time points. None of the patients developed de novo donor-specific antibodies, despite a fourfold expansion in T follicular helper cells at 1 year posttransplantation. In sum, facial transplantation is frequently complicated by a codominant interferon-γ/interleukin-17-mediated acute cellular rejection process. Despite that, medium-term outcomes are promising with no evidence of de novo donor-specific antibody development.

The management of antibody-mediated rejection in the first presensitized recipient of a full-face allotransplant.

We report on the management of the first full-face transplantation in a sensitized recipient with a positive preoperative crossmatch and subsequent antibody-mediated rejection (AMR). The recipient is a 45-year-old female who sustained extensive chemical burns, with residual poor function and high levels of circulating anti-HLA antibodies. With a clear immunosuppression plan and salvage options in place, a full-face allotransplant was performed using a crossmatch positive donor. Despite plasmapheresis alongside a standard induction regimen, clinical signs of rejection were noted on postoperative day 5 (POD5). Donor-specific antibody (DSA) titers rose with evidence of C4d deposits on biopsy. By POD19, biopsies showed Banff Grade III rejection. Combination therapy consisting of plasmapheresis, eculizumab, bortezomib and alemtuzumab decreased DSA levels, improved clinical exam, and by 6 months postop she had no histological signs of rejection. This case is the first to demonstrate evidence and management of AMR in face allotransplantation. Our findings lend support to the call for an update to the Banff classification of rejection in vascularized composite tissue allotransplantation (VCA) to include AMR, and for further studies to better classify the histology and mechanism of action of AMR in VCA.

Systematic review of molecular mechanism of action of negative-pressure wound therapy.

BACKGROUND: Negative-pressure wound therapy (NPWT) promotes angiogenesis and granulation, in part by strain-induced production of growth factors and cytokines. As their expression profiles are being unravelled, it is pertinent to consider the mode of action of NPWT at the molecular level. METHODS: MEDLINE (January 1997 to present), Embase (January 1997 to present), PubMed (no time limit), the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Register were searched for articles that evaluated the influence of NPWT on growth factor expression quantitatively. RESULTS: Sixteen studies met the inclusion criteria. Tumour necrosis factor expression was reduced in acute and chronic wounds, whereas expression of interleukin (IL) 1ß was reduced in acute wounds only. Systemic IL-10 and local IL-8 expression were increased by NPWT. Expression of vascular endothelial growth factor, fibroblast growth factor 2, transforming growth factor ß and platelet-derived growth factor was increased, consistent with mechanoreceptor and chemoreceptor transduction in response to stress and hypoxia. Matrix metalloproteinase-1, -2, -9 and -13 expression was reduced but there was no effect on their enzymatic inhibitor, tissue inhibitor of metalloproteinase 1. CONCLUSION: Cytokine and growth factor expression profiles under NPWT suggest that promotion of wound healing occurs by modulation of cytokines to an anti-inflammatory profile, and mechanoreceptor and chemoreceptor-mediated cell signalling, culminating in angiogenesis, extracellular matrix remodelling and deposition of granulation tissue. This provides a molecular basis for understanding NPWT.

Identification of a novel high molecular weight protein preferentially expressed by sinusoidal endothelial cells in normal human tissues.

Mouse mAb MS-1, raised against human spleen, detects an endothelial cell antigen abundantly expressed by the sinusoidal endothelia of spleen, lymph node, liver, and adrenal cortex, but absent from nonsinusoidal continuous endothelia in these organs. Immunoelectron microscopy of splenic tissue demonstrates that the MS-1 antigen is predominantly deposited at zones of intercellular contact between adjacent sinusoidal endothelial cells. mAb MS-1 also reacts with a variable proportion of high endothelial venules in tonsil, but not in other lymphoid tissues, and with an interstitial dendritic cell population most abundant in placenta. mAb MS-1 does not react with cultured resting or mediator- activated human umbilical vein endothelial cells, dermal fibroblasts, peripheral blood mononuclear cells, or the cell lines U937, HL-60, K562 or Mo7E; it does react with the primitive myeloid cell line KG-1. mAb MS-1 immunoprecipitates a major protein of 215 kD and minor proteins of 320 and 120 kD from splenic extracts as analyzed by SDS-PAGE with reduction. These proteins are soluble in aqueous buffers. Immunoprecipitation from KG-1 cell lysates detects four proteins of 280, 300, 205, and 120 kD; the 300-, 205-, and 120-kD species, presumably corresponding to the 320-, 215-, and 120-kD species in spleen, respectively, are secreted into the media. Under nonreducing conditions, immunoprecipitates from KG-1 cell lysates or conditioned media contain one predominant 300-kD species; upon isolation and reduction, this 300-kD species separates into the previously observed 300-, 205-, and 120-kD species. Pulse-chase experiments and limited proteolysis peptide mapping suggest that the 280-kD species is a precursor of the mature 300-kD species which may be subsequently cleaved to yield the 205- and 120-kD species. Because of its size, solubility and expression pattern, the antigen recognized by mAb MS-1 is likely to be an extracellular matrix protein utilized by endothelial cells of contorted, large caliber, or leaky microvessels that lack a well-formed basement membrane.

Epiligrin, a component of epithelial basement membranes, is an adhesive ligand for alpha 3 beta 1 positive T lymphocytes.

The cutaneous T cell lymphomas (CTCL), typified by mycosis fungoides, and several chronic T cell mediated dermatoses are characterized by the migration of T lymphocytes into the epidermis (epidermotropism). Alternatively, other types of cutaneous inflammation (malignant cutaneous B cell lymphoma, CBCL, or lymphocytoma cutis, non-malignant T or B cell type) do not show evidence of epidermotropism. This suggests that certain T lymphocyte subpopulations are able to interact with and penetrate the epidermal basement membrane. We show here that T lymphocytes derived from patients with CTCL (HUT 78 or HUT 102 cells), adhere to the detergent-insoluble extracellular matrix prepared from cultured basal keratinocytes (HFK ECM). HUT cell adhesion to HFK ECM was inhibitable with monoclonal antibodies (mAbs) directed to the alpha 3 (P1B5) or beta 1 (P4C10) integrin receptors, and could be up-regulated by an activating anti-beta 1 mAb (P4G11). An inhibitory mAb, P3H9-2, raised against keratinocytes identified epiligrin as the ligand for alpha 3 beta 1 positive T cells in HFK ECM. Interestingly, two lymphocyte populations could be clearly distinguished relative to expression of alpha 3 beta 1 by flow cytometry analysis. Lymphokine activated killer cells, alloreactive cytotoxic T cells and T cells derived from patients with CTCL expressed high levels of alpha 3 beta 1 (alpha 3 beta 1high). Non-adherent peripheral blood mononuclear cells, acute T or B lymphocytic leukemias, or non-cutaneous T or B lymphocyte cell lines expressed low levels of alpha 3 beta 1 (alpha 3 beta 1low). Resting PBL or alpha 3 beta 1low T or B cell lines did not adhere to HFK ECM or purified epiligrin. However, adhesion to epiligrin could be up-regulated by mAbs which activate the beta 1 subunit indicating that alpha 3 beta 1 activity is a function of expression and affinity. In skin derived from patients with graft-vs.-host (GVH) disease, experimentally induced delayed hypersensitivity reactions, and CTCL, the infiltrating T cells could be stained with mAbs to alpha 3 or beta 1 and were localized in close proximity to the epiligrin-containing basement membrane. Infiltrating lymphocytes in malignant cutaneous B disease (CBCL) did not express alpha 3 beta 1 by immunohistochemical techniques and did not associate with the epidermal basement membrane. The present findings clearly define a function for alpha 3 beta 1 in T cells and strongly suggest that alpha 3 beta 1 interaction with epiligrin may be involved in the pathogenesis of cutaneous inflammation.

Targeted disruption of the pemphigus vulgaris antigen (desmoglein 3) gene in mice causes loss of keratinocyte cell adhesion with a phenotype similar to pemphigus vulgaris.

In patients with pemphigus vulgaris (PV), autoantibodies against desmoglein 3 (Dsg3) cause loss of cell-cell adhesion of keratinocytes in the basal and immediate suprabasal layers of stratified squamous epithelia. The pathology, at least partially, may depend on protease release from keratinocytes, but might also result from antibodies interfering with an adhesion function of Dsg3. However, a direct role of desmogleins in cell adhesion has not been shown. To test whether Dsg3 mediates adhesion, we genetically engineered mice with a targeted disruption of the DSG3 gene. DSG3 -/- mice had no DSG3 mRNA by RNase protection assay and no Dsg3 protein by immunofluorescence (IF) and immunoblots. These mice were normal at birth, but by 8-10 d weighed less than DSG3 +/- or +/+ littermates, and at around day 18 were grossly runted. We speculated that oral lesions (typical in PV patients) might be inhibiting food intake, causing this runting. Indeed, oropharyngeal biopsies showed erosions with histology typical of PV, including suprabasilar acantholysis and "tombstoning" of basal cells. EM showed separation of desmosomes. Traumatized skin also had crusting and suprabasilar acantholysis. Runted mice showed hair loss at weaning. The runting and hair loss phenotype of DSG3 -/- mice is identical to that of a previously reported mouse mutant, balding (bal). Breeding indicated that bal is coallelic with the targeted mutation. We also showed that bal mice lack Dsg3 by IF, have typical PV oral lesions, and have a DSG3 gene mutation. These results demonstrate the critical importance of Dsg3 for adhesion in deep stratified squamous epithelia and suggest that pemphigus autoantibodies might interfere directly with such a function.

Development of pemphigus vulgaris-like lesions in severe combined immunodeficiency disease mice reconstituted with lymphocytes from patients.

Pemphigus vulgaris is an autoimmune blistering disease that is induced by binding of antibodies to a 130/85-kD protein complex on epidermal keratinocytes. An in vivo experimental model of this disease was developed by reconstituting severe combined immunodeficiency (SCID) mice with 1-10 x 10(7) PBL from patients with naturally occurring pemphigus vulgaris. Of 49 reconstituted mice, 34 (69%) produced human IgG levels of > 0.1 mg/ml. Circulating anti-pemphigus antibodies were found in 20 of the 34 successfully reconstituted mice; 44% of these animals had deposits of human IgG in their own skin after it was traumatized by either heat or cold. Spontaneous pemphigus vulgaris-like blisters associated with human IgG deposits were rarely found in mouse skin. By contrast, allogeneic human skin grafted to 10 to 12 mice before reconstitution with patients' PBL developed pemphigus vulgaris-like lesions containing human IgG deposits. These results demonstrate that SCID mice can serve as a model of an antibody-mediated human autoimmune skin disease.

Human/severe combined immunodeficient mouse chimeras. An experimental in vivo model system to study the regulation of human endothelial cell-leukocyte adhesion molecules.

The ability of circulating white blood cells to enter inflamed tissues is mediated by specific cell adhesion molecules thought to be expressed in a programmed and sequential manner to form an "adhesion cascade." Because of the complexity of this process, it is becoming increasingly important to develop in vivo models. Two major problems have limited the utility of current animal models. The first is the inability of many of the antibodies developed against cell adhesion molecules in human cell culture models to cross-react in animals. The second is the uncertainty in extrapolating animal (particularly rodent) findings to humans. To circumvent these problems, full thickness human skin grafts were transplanted onto immunodeficient (severe combined immunodeficient) mice. After 4-6 wk, the transplanted skin grafts closely resembled normal skin histologically and maintained their human vasculature as determined by immunohistochemical staining with human-specific endothelial cell markers. Intradermal injection of tumor necrosis factor-alpha resulted in the reversible upregulation of the leukocyte-endothelial adhesion molecules E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1, and in an active inflammatory reaction with migration of murine leukocytes into cytokine-injected areas. These results indicate that the severe combined immunodeficient mouse/human skin transplant model provides a useful in vivo system in which to study human endothelium during the process of inflammation.

Gamma-interferon inhibits collagen synthesis in vivo in the mouse.

Subcutaneous implantation of osmotic pumps into CAF1 mice resulted in the formation of thick fibrous capsules around the pumps. When pumps were loaded with recombinant murine gamma-interferon (rMuIFN-gamma) to deliver 2 X 10(3) U/h for 14 d, there was a marked decrease in thickness and collagen content of the capsules from rMuIFN-gamma-treated animals compared with capsules from animals receiving diluent alone. The collagen content of the capsules was estimated by hydroxyproline analysis of the tissue and by quantitative electron microscopy of collagen bundles. Heat-inactivated rMuIFN-gamma failed to reduce the fibrotic response in this assay. These results provide compelling evidence that gamma-interferon can down-regulate collagen synthesis in vivo and suggest the possibility that this lymphokine may be useful in the treatment of disease states characterized by excessive fibrosis.

P-glycoprotein of blood brain barrier: cross-reactivity of Mab C219 with a 190 kDa protein in bovine and rat isolated brain capillaries.

P-glycoprotein (P-gp), an active efflux pump of antitumor drugs, is strongly expressed in endothelial cells of the blood brain barrier (BBB). Two proteins (155 and 190 kDa) were detected by Western blot analysis of beef and rat capillaries with the monoclonal antibody (MAb) C219. In order to characterize the nature of these proteins, their profile of solubilization by different detergents was established and compared with that of P-gp from the CHRC5 tumoral cell line. The 155 kDa protein (p155) of capillaries and the P-gp of CHRC5 cells were well solubilized by deoxycholate and Elugent, whereas the 190 kDa kDa protein (p190) was only solubilized by sodium dodecylsulfate (SDS). Both proteins have different patterns of extraction by Triton X-114, p155 partitioning as a membrane protein, while p190 was insoluble. Deglycosylation of capillary proteins resulted in a 27-28 kDa decrease in the apparent molecular weight of p155, similar to that observed for the P-gp of CHRC5 cells, but a decrease of only 7-8 for p190. Only p155 was immunoprecipitated by MAb C219. These results suggest that only p155 is the P-gp in BBB and that MAb C219 cross-reacts with a 190 kDa MDR-unrelated glycosylated protein. Consequently, the use of this antibody, which is frequently used to detect P-gp in tumors, could be a pitfall of immunohistochemistry screening for cancer tissues and lead to false positive in the diagnosis of MDR.

Effects of cyclosporine on glucose tolerance in the rat.

In a study of prevention of spontaneous diabetes in BB rats by therapeutic doses of cyclosporine (10 mg/kg/day), the male control non-diabetes-prone rats showed glucose intolerance after a 0.25 g/kg glucose load by gavage, at 90 and 130 days of treatment. Non-BB male Wistar rats treated similarly showed glucose intolerance at 1 wk of treatment, with progressive worsening for 5 wk, then sustained up to 12 wk of treatment. Fasting euglycemia was maintained, but both pre- and postchallenge plasma insulin levels were significantly lower with cyclosporine at several time points. Total pancreatic insulin was decreased to one-third that of control after 5 wk. After withdrawal of cyclosporine, glucose tolerance returned to normal in 2 wk. Sprague-Dawley rats responded similarly and in both strains, an increase in the cyclosporine dose to 15 mg/kg/day augmented the glucose intolerance. These results demonstrate that therapeutic doses of this agent induce reversible glucose intolerance due, in part, to inhibition of insulin secretion and also possibly inhibition of synthesis, though a peripheral effect is not excluded. This hyperglycemic effect of cyclosporine has implications for its potential use in type I diabetes mellitus, transplantation, and other autoimmune disease.

Drug resistance in multiple myeloma: cyclosporin A analogues and their metabolites as potential chemosensitizers.

The malignant clone in myeloma is not eradicated by chemotherapy. Cyclosporins inhibit drug transport mechanisms, particularly the multidrug transporter p-glycoprotein 170, leading to their use as chemosensitizers. In myeloma, clonotypic blood B cells represent the major drug-resistant subset. This study compares the ability of cyclosporin A analogues and metabolites to inhibit cellular transporter(s) in myeloma and normal B cells in vitro, and evaluates their potential role in vivo. Cyclosporin A (CsA), CsG, PSC 833 or SDZ 280-446, and primary CsA and CsG metabolites, were tested for their ability to inhibit drug transport mechanisms of ex vivo malignant B cells from 81 patients with multiple myeloma as compared to B cells from normal donors, as measured by the export of the dye rhodamine 123 (Rh123) using multiparameter flow cytometry. The majority of myeloma B and normal B cells had efficient transporter function as measured by their CsA-sensitive export of Rh123. CsA and CsA analogues mediated efficient inhibition of this transport. Inhibition of dye transport by normal B cells required an approximately six-fold greater concentration of the synthetic peptolide SDZ 280-446 than was needed to optimally inhibit transport by myeloma B cells. PSC 833 and CsG were inhibitory at concentrations approximately five-fold lower than were required for CsA. Assessment of inhibitory potency in vivo indicated that the in vivo chemosensitizer levels of CsA and PSC 833 exceeded the transporter inhibitory concentration by four- and 20-fold respectively. In vivo, cyclosporins are rapidly and almost completely converted to metabolites. AM1 and AM4N, primary metabolites of CsA, mediated inhibition of transport, as did CsG metabolites GM1, GM4N and GM9. AM1 and GM9 are known to reach steady-state in vivo levels that exceed the inhibitory concentration identified here by 1.1- to 1.9-fold. Thus, cyclosporin metabolites, which accumulate in the blood during infusion of CsA and other cyclosporins, are shown here to be effective chemosensitizers for normally drug-resistant myeloma cells in vitro. Cyclosporin metabolites are considered to be less toxic than the parent drugs, suggesting that novel chemosensitization strategies designed to minimize concentrations of parent drug and maximize accumulation of primary metabolites in vivo may optimize cytotoxicity to the malignant clone in myeloma.

Computer-assisted three-dimensional reconstruction of human dermal dendrocytes.

We attempted to characterize the three-dimensional structure of dermal dendrocytes and to clarify the spatial relationships between dermal dendrocytes and mast cells, macrophages, and nerves. Normal human adult skin (breast, n = 2) was routinely processed for electron microscopy. Every other section (about 50 per data set) was collected at 80-nm intervals traversing about 8 microns of tissue. Grids showing the same cells were photographed by electron microscopy at a magnification of 4000x. Based on the 10-20 photographs per data set, cell outlines were digitized into the reconstruction program at appropriate layers and aligned. Thin, elongated cytoplasmic "dendrites" of dermal dendrocytes in two-dimensional micrographs proved to be thin, membrane-bound flaps in three-dimensional reconstruction. For dermal dendrocytes concentrated about superficial vessels (perivascular dendrocytes), the flaps enshrouded the vessel wall, and for dermal dendrocytes directly beneath the epidermis (subepidermal dendrocytes), these flaps were aligned parallel to the dermal-epidermal junction. The three-dimensional feature of dermal dendrocytes (perivascular and subepidermal) is quite similar to that of perivascular adventitial veil cells, suggesting ultrastructurally identified perivascular dendrocytes and veil cells must be identical cells. In conventional ultrathin sections, 20-40% of perivascular dendrocytes and occasional subepidermal dendrocytes were closely associated with mast cells. When viewed by computer-assisted three-dimensional reconstruction, membrane flaps of dermal dendrocytes consistently shrouded mast cell membranes for 50-90% of their perimeter; mast cells resembled a ball in a baseball glove (dermal dendrocytes). Occasional dermal dendrocytes surrounded non-myelinated nerves in the superficial dermis. Membrane flaps also enabled dermal dendrocytes to present extensive areas to the plasma membranes of adjacent monocyte/macrophages. These findings indicate that dermal dendrocytes are non-dendritic cells that are spatially related to mast cells, monocyte/macrophages, microvessels, and nerves by their membranous flaps. This suggests the need for further study of functional interactions between these cells.

Mast cell degranulation upregulates alpha 6 integrins on epidermal Langerhans cells.

The expression of the alpha 6 beta 4 and alpha 6 beta 1 integrins on epidermal Langerhans cells (LC) before and after mast cell degranulation was studied in cultured human neonatal foreskin by immunohistochemistry. Twenty-four hours after addition of mast cell secretagogues, morphine sulfate, or substance P, solitary mid-epidermal cells showed staining for the integrin subunits alpha 6, beta 4, and beta 1. This expression was not observed in cultured control explants, and immunostained cells were confirmed to be non-epithelial, dendritic cells by immuno-electron microscopy. The identity of these cells as LC was further established by coincident staining for alpha 6 and CD1a using double immunofluorescence labeling. Addition of tumor necrosis factor-alpha (TNF alpha), the predominant cytokine in mast cell granules, also induced LC to express alpha 6 integrins. Furthermore, preincubation of skin organ cultures with anti-TNF alpha antibodies or the mast cell inhibitor cromolyn sodium abrogated the ability to induce alpha 6 integrins on LC consequent to experimental mast cell degranulation by substance P. These data implicate a role for mast cell-derived TNF alpha in the regulation of the integrins alpha 6 beta 4 and alpha 6 beta 1 on LC. These findings may have important implications relevant to mechanisms for spatial localization of LC within the cutaneous compartments during immune responses.

Substance P induces the expression of an endothelial-leukocyte adhesion molecule by microvascular endothelium.

Leukocyte trafficking in normal and diseased skin appears to be initially governed by endothelial surface glycoproteins that promote adhesive interactions with circulating leukocytes. In a separate study, we have demonstrated that one of these glycoproteins, endothelial-leukocyte adhesion molecule-1 (ELAM-1), is rapidly induced on postcapillary dermal venules as a direct consequence of experimentally-elicited degranulation of adjacent mast cells (Proc Natl Acad Sci USA 86:8972-8976, 1989). A principle endogenous mediator of mast cell degranulation is the neuropeptide substance P. In this study, we exposed organ cultures of neonatal human foreskins for 45 min to substance P or to a substance P analogue (D-pro4, D-trp7,9)SP(4-11) that binds to the identical mast cell surface receptor but which does not provoke histamine release. Dermal mast cells were uniformly degranulated only in explants exposed to substance P, as judged by ultrastructural analysis. After subsequent culture in medium alone for 6 h, superficial venules of explants exposed to substance P showed evidence of ELAM-1 induction, as documented histochemically using H4/18 monoclonal antibody. ELAM-1 was not induced by substance P analogue. Furthermore, preincubation of explants with analogue or with the mast cell inhibitor, cromolyn sodium, abrogated the ability of substance P to induce ELAM-1. From these results we suggest that substance P endogenously released by dermal nerve fibers upon physiologic or electrical stimulation may be important in the regulation of endothelial-leukocyte interactions in vivo. This concept provides further evidence for a neurogenic and psychogenic modulation of the immune response, and may be relevant to the course of naturally occurring dermatoses (e.g., psoriasis) that are commonly exacerbated by emotional stress.

Expression of activation antigens by T cells infiltrating basal cell carcinomas.

The association of T lymphocytes and dendritic cells with the stromal mononuclear cell response to basal cell carcinomas has led to speculation that cellular immunity may, in part, regulate the growth and development of this neoplasm. It has not been established, however, whether these T cells are functionally competent, or simply coincidental bystanders. We examined the immunologic phenotypes of mononuclear cells in 32 lesions of basal cell carcinoma obtained from 26 patients. The majority of infiltrating mononuclear cells were T cells that were equally distributed between the helper/inducer (Leu 3a+) and cytotoxic/suppressor (Leu 2a+) subtypes; a minority of cells were dendritic and expressed Leu 6 antigen. Virtually all T cells and dendritic cells were HLA-DR+, and many (greater than 30%) of the T cells expressed antigens consistent with stages of ongoing activation (T9, T10). TS2/7, a novel monoclonal antibody recently documented to identify activation-specific subcomponents of 210/165/130 kD glycoprotein complex present on the surface of mitogen- or alloantigen-stimulated human T cells, was also used. Greater than 50% of the T cells observed were TS2/7+. These observations provide in situ immunomorphologic evidence of stromal T cell activation in association with basal cell carcinomas, and suggest a role for active and ongoing cellular immune mechanisms as a determinant of local biological behavior of this neoplasm.