Loss of ATP2A2 Allows Herpes Simplex Virus 1 Infection of a Human Epidermis Model by Disrupting Innate Immunity and Barrier Function

Destruction of epidermal barrier function associated with atopic dermatitis or Darier's disease often causes severe secondary skin infections. Patients with skin barrier disorders often repeatedly acquire Kaposi varicelliform eruption, which is caused by herpes simplex virus, but the underlying mechanisms and effective preventive methods have yet to be found. Viral infection through an impaired epidermal barrier can be prevented by enhancing innate immunity and/or inhibiting viral entry. In this study, we established a three-dimensional skin barrier dysfunction model by silencing ATP2A2, which is mutated in some Darier's disease patients. We confirmed the loss of desmosomes and presence of histopathological clefts in the suprabasal layer. Herpes simplex virus 1 applied to the stratum corneum infected the deep epidermis. An innate immune reaction was assessed by evaluating the expression of IFNB1 and related genes. Pretreatment with polyinosinic-polycytidylic acid alone or plus the antimicrobial peptide, LL37 enhanced IFN-β production and suppressed viral replication. Furthermore, topical application of a white petrolatum ointment containing heparin, which binds viral glycoproteins related to virus entry, strongly inhibited viral replication, probably by inhibiting invasion. Our human barrier-dysfunctional model will have future application for identifying the mechanism of Kaposi varicelliform eruption onset, preventive methods, and therapies.

[Influence of immunovac-VP-4 therapy on innate immunity effectors in patients with darier erythema annulare centrifugum]

AIM

Detection of features of functioning ofinnate and adaptive immunity pathways in patients with Darier erythema annulare centrifugum (EAC).

MATERIALS AND METHODS

14 EAC patients aged 14 - 52 years were examined. The patients were ranked based on therapy variant. The first group consisted of 6 patients who had received Immunovac-VP-4 (Immunovac) against the background of basic therapy; the second group (4 patients) received cagocel against the background of basic therapy; the third group (4 patients) received only basic therapy; the group of healthy individuals consisted of 15 individuals. All the patients had the level ofcytokines in blood sera determined by solid-phase EIA by using Biosource (Austria) test-systems. Evaluation of TLR expression in peripheral blood mononuclear lymphocytes and keratinocytes was carried out by flow cytometry method by using monoclonal antibodies (Catlag Laboratories, USA) against the corresponding antigens; evaluation of content of lymphocyte subpopulations in blood was carried out by using monoclonal antibodies by flow cytometry method on FacsCalibur flow cytometer (Becton Dickinson, USA).

RESULTS

Immunotherapy by Immunovac and cagocel facilitated the increase of CD3+, CD4+, CD8+. Immunovac facilitated a significant increase ofinitially low values ofCD25+, CD95+ and normalization of CD72+; normalization of IgM level. Immunovac increased the level of serum IL-2, induced the increase of IFN-gamma synthesis in contrast to cagocel and basic therapy, the administration of those caused its decrease. TGF-beta increased during the course of Immunovac immunotherapy and decreased during basic therapy. In the course of basic therapy a significant increase of initially high level ofcytokine IL-I beta was observed.

CONCLUSION

Immunovac therapy resulted in correction of content of lymphocyte populations, sera cytokines, facilitating the normalization of immunocompetent cell proliferation processes, activation of NK-cells, macrophages and at the same time suppression of DTH reactions. Immunovac facilitated the enhancement ofTLR3, 9 expression in the skin that indicates the inclusion ofintracellular receptor mechanisms of innate immunity.

Immunohistochemical Examination of P-cadherin in Bullous and Acantholytic Skin Diseases

Autoimmune blistering diseases (pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, dermatitis herpetiformis) and certain genodermatoses with acantholysis (Darier-disease, Hailey-Hailey disease) have different aetiological factors, but all result in bulla formation and/or in acantholysis. Cadherins are Ca++-dependent cell-cell adhesion molecules which play an important role in the cellular connection between normal cells. P-cadherin is involved in the selective adhesion of epidermal cells, and is expressed only on the surfaces of the two basal layers. We examined the expression of P-cadherin in some autoimmune bullous skin diseases and Darier's disease using immunohistochemistry and found P-cadherin to be strongly upregulated. We believe the upregulation is compensatory to the primary pathophysiological events in the various bullous dermatoses.

Immunohistochemical distribution of CD44 and desmoplakin I & II in Hailey-Hailey's disease and Darier's disease

The cell-surface glycoprotein CD44 is found on a wide variety of cells including epidermal cells. It is involved in cell to cell adhesion. Desmoplakin I & II are important components of the attachment plaque of desmosomes. In this study, we compared the distribution patterns of anti-CD44 and anti-desmoplakin I & II in Hailey-Hailey's disease and Darier's disease. In the normal skin, anti-CD44 stained the entire periphery of epidermal keratinocytes while anti-desmoplakin I & II produced dotted staining patterns along the periphery of epidermal keratinocytes. In Hailey-Hailey's disease and Darier's disease, the staining pattern of anti-CD44 on acantholized keratinocytes did not change, but anti-desmoplakin I & II lost their peripheral, dotted patterns and stained diffusely in the cytoplasm in most acantholytic cells. These results suggest that, in Hailey-Hailey's disease and Darier's disease, CD44 may be intact even in acantholytic cells but abnormalities of desmoplakin exist in such cells.

Adhesion molecules and related proteins in Darier's disease and Hailey-Hailey disease

We have used antibodies to plakoglobin and E-cadherin: the lectins, peanut agglutinin (PNA) and soybean agglutinin (SBA); and sera from patients with the autoimmune diseases pemphigus vulgaris (PV) or pemphigus foliaceus (PF), in an immunohistological study of Darier's disease and Hailey-Hailey disease. There was normal expression of plakoglobin, E-cadherin, lectins and pemphigus antigens at the periphery of keratinocytes in uninvolved skin. Clumps of plakoglobin were detected within acantholytic cells in Hailey-Hailey disease, whereas expression was diffuse in acantholytic cells in Darier's disease. This difference may reflect differences in the pathogenesis of acantholysis. E-cadherin expression was weak or absent at the periphery of some acantholytic cells; lectin binding was sometimes reduced around acantholytic cells, and pemphigus antibodies did not bind to the acantholytic cells involved skin in either disease. Internalization, conformational changes or proteolysis may alter the expression of extracellular epitopes by acantholytic cells.

Immunological parameters in Darier's disease

Patients with Darier's disease have frequently been observed to develop severe bacterial and viral infections. Previous studies have indicated some derangement in the immune system, even though no consistent or specific abnormality has yet been demonstrated. We performed the results of immunologic studies in 10 patients with Darier's disease. In each patient humoral immunity and cell-mediated immunity (in vivo and in vitro) were evaluated and leukocyte chemotactic function was assayed. Humoral immunity was normal; as regards clusters of differentiation (CD), a slight increase in CD4 lymphocyte subpopulations was observed in 7 patients and of CD4/CD8 ratio in 1 case. The lymphocyte responses to phytohemagglutinin and concanavalin A were normal, whereas the response to pokeweed mitogen was decreased slightly, but not significantly. Normal random and chemotactic mobility was found in all the patients except one. The data obtained do not show important immunological alterations. Our patients did not have a high propensity to develop severe infections and this may explain the absence of significant immunological derangement. Our data confirm that no immunological derangement is associated with Darier's disease.

Immunologic studies in Darier's disease

Humoral and cellular immunity were evaluated in 10 patients with Darier's disease. The mean levels of serum immunoglobulins, serum complement, peripheral macrophages, and peripheral B and T lymphocytes were within normal limits. Secretory IgA was present in all patients studied. Skin tests for delayed hypersensitivity revealed complete anergy in one of the eight patients tested. Lymphocyte transformation tests revealed statistically significant enhanced responsiveness to both PHA and ConA mitogens in several concentrations studied. These findings may suggest either the existence of alterations in immunoregulation of lymphocyte subpopulations in Darier's disease or may be limited to alterations in membrane functions of certain lymphocyte subpopulations which can be detected only in vitro. The role that such immunologic aberrations may play in the pathogenesis of Darier's disease is still obscure.

Cell-mediated immunity in Darier's disease: effect of systemic retinoid therapy

In five patients with Darier's disease, lymphocyte subpopulations, lymphocyte responsiveness to phytohaemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) and purified protein derivative of tuberculin (PPD), leukocyte migration inhibitory factor (LMIF) production and suppressor cell activities were studied before and during oral etretinate treatment. Pre-therapy investigations of cell-mediated immunity showed no severe immunological dysfunction, although high responses to supra-optimal Con A concentrations suggested abnormalities in immunoregulatory lymphocyte subpopulations. In addition, two patients showed enhanced LMIF production upon stimulation with Con A, PWM and PPD. Retinoid therapy decreased the number of peripheral blood total leukocytes, lymphocytes and T-cells, normalized the LMIF production, and decreased the lymphocyte responses to mitogens. Furthermore, the dose-response curve to Con A changed toward normal and the suppressor cell activity regulating Con A responses tended to increase.

Darier's disease: a partially immunodeficient state

Darier's disease (Keratosis follicularis) a dominantly inherited keratinizing disorder of the skin, is associated with the development of severe, progressive viral and bacterial skin infections. We investigated the possibility that an inadequacy of the immune system might be responsible for this tendency. Seven of our 8 patients with Darier's disease showed complete anergy to common skin test antigens and their peripheral blood lymphocytes failed to produce the lymphokine, leukocyte inhibitory factor (LIF) in vitro when stimulated with the same antigens. One Darier's patient and 6 controls showed positivity to at least one skin test antigen and produced lymphokine in vitro to the appropriate antigen. All patients had normal leukocyte and differential counts and normal numbers of circulating T and B cells. All 8 patients with Darier's disease demonstrated no proliferative response to optimal doses of the T cell mitogen Con A while showing normal responses to the T cell stimulant PHA and the T cell dependent B cell stimulant PWM. This previously unreported finding suggests a subtle abnormality of T cells in Darier's and might be a marker for these patients. Serum from 2 patients with Darier's disease did not suppress the in vitro immunologic activity of lymphocytes from normals. Finally, 13-Cis-retinoic acid in dosages adequate to clear their skin disease did not alter the in vivo or in vitro immunologic functions in 3 Darier's patients, suggesting that the immune dysfunction is not a secondary phenomenon.

Cell-mediated immunity in Darier's disease

Darier's disease, often complicated by skin infections, has been linked with a depressed cell-mediated immunity. Four moderate to severely affected patients with a negative history of skin infections were studied. T cell function was evaluated by standard delayed hypersensitivity skin tests, enumeration of peripheral T cell-mediated immunity was found. The significance of the results when compared with prior studies is discussed.

Darier's disease: an immunologic study

Darier's disease is frequently complicated by bacterial skin infections and occasionally by Kaposi's varicelliform eruption. Postulating that defective host immunologic competence might explain these infections, humoral and cell-mediated immunity (CMI) were evaluated in four patients. Humoral immunity was normal as demonstrated by quantitative immunoglobulins, isohemagglutinins, direct skin immunofluorescence, and B-cell counts. The CMI was evaluated by standard delayed type hypersensitivity skin tests, T-cell counts, lymphocyte transformation assays, macrophage inhibition factor (MIF) assays, and skin windows. Blunted lymphocyte blastogenesis, MIF, and skin window response indicated depressed CMI. Polymorphonuclear leukocyte chemotaxis and phagocytosis were normal.