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Background: An alarming increase in the number of patients with chronic and recurrent dermatophytosis has invoked the need to study the immunological parameters of the host., Objectives: To evaluate delayed type of hypersensitivity (DTH) response and immediate hypersensitivity (IH) response by flow cytometry evaluation of immune cells from peripheral blood and intradermal trichophyton skin test in patients with recurrent dermatophytosis., Methods: A hundred patients with recurrent dermatophytosis and 50 controls (healthy controls and acute dermatophytosis controls) were included. Relevant risk factors for recurrence were analysed, and serum IgE levels were estimated. Flow cytometry evaluation of immune cells in peripheral blood and intradermal trichophyton skin test was done. Dermatophyte pathogens were isolated, and antifungal susceptibility was performed., Results: Trichophyton mentagrophytes complex (95.84%) and T. rubrum (4.16%) were isolated in culture. Serum IgE was elevated in 83.15% cases (p = .01). IFN-γ + cells (p = .0501, p = .0001, p = .0014), Th1 cells (p = .1197, p = .0024, p = .0169), IL-17 + cells (p = .0127, p = .0006, p = .0007) and Th17 cells (p = .0634, p = .0001, p = .0054) were reduced, and IL-4 + cells (p = .0108, p = .0175, p = .0018) were increased in cases. Intradermal test demonstrated negative DTH response in all cases (p < .001, p < .001, p < .001), strongly positive IH response in 6%, and borderline positive IH response in 85% cases (p = .018, p < .001, p < .001). Topical corticosteroids application, undergarment types (tight fit), poor frequency of washing clothes, family history of tinea, sharing of towels were significant risk factors for recurrent dermatophytosis., Conclusions: Reduced IFN-γ + , Th1, IL-17 + and Th17 cells population along with impaired DTH response by the intradermal test was observed in patients with recurrent dermatophytosis., (© 2021 Wiley-VCH GmbH.)

The skin is the outermost layer of the body and is exposed to many environmental stimuli, which cause various inflammatory immune responses in the skin. Among them, fungi are common microorganisms that colonize the skin and cause cutaneous fungal diseases such as candidiasis and dermatophytosis. The skin exerts inflammatory responses to eliminate these fungi through the cooperation of skin-component immune cells. IL-17 producing cells are representative immune cells that play a vital role in anti-fungal action in the skin by producing antimicrobial peptides and facilitating neutrophil infiltration. However, the actual impact of IL-17-producing cells in cutaneous fungal infections remains unclear. In this review, we focused on the role of IL-17-producing cells in a series of cutaneous fungal infections, the characteristics of skin infectious fungi, and the recognition of cell components that drive cutaneous immune cells.

Dermatophytoses (ringworms) are among the most frequent skin infections and are a highly prevalent cause of human disease worldwide. Despite the incidence of these superficial mycoses in healthy people and the compelling evidence on chronic and deep infections in immunocompromised individuals, the mechanisms controlling dermatophyte invasion in the skin are scarcely known. In the last years, the association between certain primary immunodeficiencies and the susceptibility to severe dermatophytosis as well as the evidence provided by novel experimental models mimicking human disease have significantly contributed to deciphering the basic immunological mechanisms against dermatophytes. In this review, we outline the current knowledge on fungal virulence factors involved in the pathogenesis of dermatophytoses and recent evidence from human infections and experimental models that shed light on the cells and molecules involved in the antifungal cutaneous immune response. The latest highlights emphasize the contribution of C-type lectin receptors signaling and the cellular immune response mediated by IL-17 and IFN-γ in the anti-dermatophytic defense and skin inflammation control., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Burstein, Beccacece, Guasconi, Mena, Cervi and Chiapello.)

Dermatophytosis is a cutaneous mycosis caused by a plethora of keratinophilic fungi, but Trichophyton rubrum is the most common etiological agent. Despite its high prevalence worldwide, little is known about the host defense mechanisms in this infection, particularly the in situ immune response. Using an immunohistochemistry approach, we investigated the density of CD1a+, factor XIIIa+ and CD68+ cells in the skin of dermatophytosis patients. Langerhans cells (CD1a+ cells) were significantly decreased in the epidermis of patients, both in affected and unaffected areas. In the dermis, however, no differences in the density of macrophages (CD68+ cells) and dermal dendrocytes (factor XIIIa+ cells) were observed. These results suggest that the decreased number of Langerhans cells may be a risk factor for development of dermatophytosis.

Background: Dermatophytes are keratinophilic fungi, that usually infect the hair, stratum corneum, and nails. However, dermatophytes occasionally invade the dermis, subcutaneous tissues, and internal organs, resulting in a condition called deep dermatophytosis. We report a case of an unusual presentation of Trichophyton rubrum infection causing multiple fungal abscesses in the lower extremities of an immunocompromised patient., Case Presentation: A 66-year-old male who had been receiving immunosuppressive drugs for 7 years developed numerous subcutaneous nodules in the lower extremities. The yellow purulent fluid obtained from the cyst was positive for T. rubrum. Topical bifonazole cream was effective for tinea pedis, but oral Sporanox 400 mg/day was discontinued after 2 months because the patient died from pneumonia after hospitalization for a lumbar fracture., Conclusions: Although deep dermatophytosis is very rare, dermatomycosis should be considered in any examination of patients who are receiving immunosuppressive drugs. Fungi can enter the bloodstream and disseminate to distant major organs, including the lymph nodes, liver, brain, and bone, which often causes systemic infections that can be fatal.

Dermatophytoses are among the most common fungal infections worldwide, but little is known about the immune response in them. By comparing Trichophyton benhamiae acute superficial dermatophytosis in wild-type and Rag2 -/- mice, we showed that TCR-mediated immunity is critical for fungal clearance and clinical recovery. In WT mice, CD4 + T cells isolated from the skin-draining lymph nodes exhibit both T helper type (Th) 1 and Th17 differentiation during infection, with regard to produced cytokines or mRNA levels of transcription factors. Using IL-17A- and IFN-γ-deficient mice, we showed that IL-17A and IFN-γ are individually dispensable but together contribute to the optimal resolution of dermatophytosis. Furthermore, we generated and infected IL-17A and IFN-γ double-deficient mice and showed that both fungal clearance and clinical recovery were much lower in these mice than in single-deficient mice, suggesting the complementary roles of the two cytokines in dermatophytosis resolution. Thus, our data suggest that TCR-mediated immunity is critical for the optimal control of superficial dermatophytosis and that adaptive immunity is polarized to both Th1 and Th17 responses, with the Th17 antifungal response acting on dermatophyte clearance and the Th1 response being involved in both fungal clearance and Th17-inflammation down-modulation., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

The prevalence of Trichophyton-induced superficial skin mycosis is very high among human patients. Dermatophytes generally infect the epidermis, especially the stratum corneum, forming scales, hyperkeratosis, and vesicles. The important roles played by the immune system in Trichophyton infection are detection of fungal invasion and elimination of fungi.These immune mechanisms are presumed to involve not only innate immunity but also acquired immunity. Therefore, there is a substantial need for studies on treatment methods based on new basic knowledge, and the elucidation of immunological mechanisms of Trichophyton-induced inflammatory reactions is especially important.However, since Trichophyton cannot colonize on the mouse skin, we tried to develop a model for Trichophyton inflammation induced by trichophytin extracted from Trichophyton mentagrophytes using a method based on contact hypersensitivity.Trichophytin is a crude extract that mainly contains fungal cell wall constituents including β-glucan and zymosan. In this model, TLR2, TLR4, and dectin-1 were highly expressed, and production of IL-17A and IL23 was observed. This indicates that we succeeded in inducing fungal-specific inflammation in the mice.In this review, we introduce a mouse Trichophyton inflammation model developed to investigate the immunological mechanisms of Trichophyton-induced inflammatory reactions. In addition, we report results of evaluation of anti-inflammatory and anti-itching effects of anti-fungal agents using the inflammation model.

Purpose: Increasing incidence of onychomycosis and tinea pedis in humans of industrialized countries together with deep tissue infections are a therapeutic challenge in clinical mycology. For a better understanding of the pathology and immunology of infection, the authors analyze the exoproteomes of three reference strains of the most common clinical dermatophyte species (Trichophyton rubrum, Trichophyton interdigitale, Arthroderma benhamiae) and of Trichophyton strains isolated from affected patients., Experimental Design: Extracellular proteins of those in vitro grown strains are separated via 2D High Performance Electrophoresis and identified by mass spectrometry to find proteins with provoked host immune reactivity., Results: More than 80 secreted proteins including virulence factors such as peptidases and other hydrolases are identified. By Western blotting with respective patient sera, up to 31 proteins with significant antigen-antibody reactions are detected in comparison with control sera, for example, peptidases as well as several oxidoreductases. One protein, beta-glucosidase F2SZI9 seems to be a commonly processed antigen in all Trichophyton infections., Conclusions and Clinical Relevance: These first global exoproteome data of three dermatophyte species can be a stepping stone on the way to further study the molecular mechanisms of Trichophyton pathogenicity-associated traits. Possible candidates for potential new diagnostic methods or vaccination have to be validated in further investigations., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The release of biomolecules critically affects all pathogens and their establishment of diseases. For the export of several biomolecules in diverse species, the use of extracellular vesicles (EVs) is considered to represent an alternative transport mechanism, but no study to date has investigated EVs from dermatophytes. Here, we describe biologically active EVs from the dermatophyte Trichophyton interdigitale , a causative agent of mycoses worldwide. EV preparations from T. interdigitale were examined using nanoparticle-tracking analysis, which revealed vesicular structures 20-380 nm in diameter. These vesicles induced the production of proinflammatory mediators by bone marrow-derived macrophages (BMDMs) and keratinocytes in a dose-dependent manner, and an addition of the EVs to BMDMs also stimulated the transcription of the M1-polarization marker iNOS (inducible nitric oxide synthase) and diminished the expression of the M2 markers arginase-1 and Ym-1. The observed M1 macrophages' polarization triggered by EVs was abolished in cells obtained from knockout Toll-like receptor-2 mice. Also, the EVs-induced productions of pro-inflammatory mediators were blocked too. Furthermore, the EVs from T. interdigitale enhanced the fungicidal activity of BMDMs. These results suggest that EVs from T. interdigitale can modulate the innate immune response of the host and influence the interaction between T. interdigitale and host immune cells. Our findings thus open new areas of investigation into the host-parasite relationship in dermatophytosis.

Despite worldwide prevalence of superficial mycoses, the immune response in dermatophytosis has scarcely been investigated. In this study, we developed a model of superficial skin infection in C57BL/6 mice with Microsporum canis, a highly prevalent human pathogen. This model mimics mild inflammatory human dermatophytosis, characterized by neutrophil recruitment and fungal invasion limited to the epidermis and exhibits the establishment of a specific T helper type 17 immune response during infection. By using IL-17RA- or IL-17A/F-deficient mice we showed that, in the absence of a functional IL-17 pathway, M. canis extensively colonizes the epidermis and promotes an exaggerated skin inflammation and a shift to an IFN-γ-mediated (T helper type 1) response. IL-17 signaling was not involved in neutrophil influx to skin or fungal invasion to deeper tissues. Finally, this study shows that skin langerin-expressing cells contribute to the antifungal T helper type 17 response in vivo. In conclusion, these data directly show a dual function of IL-17 cytokines in dermatophytosis by controlling superficial infection and down-modulating a T helper type 1 antifungal response., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Opportunistic infections have occurred during dimethyl fumarate (DMF) therapy., Objective: Diffuse skin dermatophytosis which occurred during DMF therapy in the setting of lymphopenia is described., Methods and Results: The clinical course, the lymphocyte subset profile, and dermatologic evaluations were reviewed. In both instances, there was no other cause of lymphopenia or immune suppression, and it is likely that the tinea infections are associated with DMF therapy., Conclusion: The occurrence of dermatophytosis widens the spectrum of opportunistic infections associated with DMF therapy. Further research is necessary to fully elucidate the mechanism of lymphopenia and potentially impaired immune competence during DMF therapy.

Background: Dermatophytes are the most common cause of superficial fungal infections in humans. Deep dermatophytosis, however, is rare, described to date only in isolated case reports, usually in the setting of systemic immunosuppression., Objective: To present the 15-year experience of a tertiary dermato-mycology clinic with the diagnosis and treatment of deep dermatophytosis., Methods: Patients were identified by database search. Clinical, mycological, histological, and treatment data were collected from the medical files., Results: Ten patients were identified: nine after solid-organ transplantation and one undergoing chemotherapy, all diagnosed within 3 years after beginning immunosuppression (average 7.5 months). The infective agent in nine cases was Trichophyton rubrum. All patients presented with concurrent superficial fungal infections. Complete resolution was noted in response to systemic antifungal agents. There was no histological evidence of hair-follicle involvement., Limitations: The limitations of the study were the retrospective design and the small cohort size., Conclusion: This case-series study suggests that deep dermatophytosis is a separate entity, distinct from Majocchi's granuloma. It occurs only in immunocompromised patients and is characterized by discrete nodules, an indolent course, the absence of follicular invasion, and proximity to a superficial dermatophyte infection. Systemic antifungal treatment leads to complete resolution. The urgent need for the treatment of superficial fungal infections in immunocompromised patients is emphasized.

Despite their superficial localization in the skin, pathogenic dermatophytes can induce a complex but still misunderstood immune response in their hosts. The cell-mediated immunity (CMI) is correlated with both clinical recovery and protection against reinfection, and CD4+ T lymphocytes have been recognized as a crucial component of the immune defense against dermatophytes. Before the discovery of the Th17 pathway, CMI was considered to be only dependent of Th1 cells, and thus most studies on the immunology of dermatophytosis have focused on the Th1 pathway. Nevertheless, the fine comparative analysis of available scientific data on immunology of dermatophytosis in one hand and on the Th17 pathway mechanisms involved in opportunistic mucosal fungal infections in the other hand reveals that some key elements of the Th17 pathway can be activated by dermatophytes. Stimulation of the Th17 pathway could occur through the activation of some C-type lectin-like receptors and inflammasome in antigen-presenting cells. The Th17 cells could go back to the affected skin and by the production of signature cytokines could induce the effector mechanisms like the recruitment of polymorphonuclear neutrophils and the synthesis of antimicrobial peptides. In conclusion, besides the Th1 pathway, which is important to the immune response against dermatophytes, there are also growing evidences for the involvement of the Th17 pathway.

Innate immunity is the host first line of defense against pathogens. However, only in recent years, we are beginning to better understand the ways it operates. A key player is this branch of the immune response that are the phagocytes, as macrophages, dendritic cells and neutrophils. These cells act as sentinels, employing specialized receptors in the sensing of invaders and host injury, and readily responding to them by production of inflammatory mediators. They afford protection not only by ingesting and destroying pathogens, but also by providing a suitable biochemical environment that shapes the adaptive response. In this review, we aim to present a broad perspective about the role of phagocytes in dermatophytosis, focusing on the mechanisms possibly involved in protective and non-protective responses. A full understanding of how phagocytes fit in the pathogenesis of these infections may open the venue for the development of new and more effective therapeutic approaches.

Diversity in the macrophage models currently employed in immunology studies may lead to opposed results and interpretations. In this study, we aimed to analyze the suitability of J774 macrophage-like cells as a model for the interaction between the dermatophyte Trichophyton rubrum and macrophages. J774 cells were competent in fungal phagocytosis, but succumbed to hyphal growth. Nevertheless, they could also secrete IL-1β in response to the dermatophyte. On the opposite direction, inflammatory, thioglycollate-induced peritoneal macrophages did not succumb to fungal growth and showed no significant IL-1β production. The proteomic profiling of these cells uncovered vimentin and plastin-2 as proteins whose abundance was altered by the fungal interaction. Our study indicates that this cell line could be an interesting tool in the investigation of T. rubrum infection biology.

Dermatophytosis is one of the most common human infections affecting both immunocompetent individuals and immunocompromised patients, in whom the disease is more aggressive and can reach deep tissues. Over the last decades, cases of deep dermatophytosis have increased and the dermatophyte-host interplay remains poorly investigated. Pattern recognition molecules, such as Toll-like receptors (TLR), play a crucial role against infectious diseases. However, there has been very little research reported on dermatophytosis. In the present study, we investigated the role of TLR2 during the development of experimental deep dermatophytosis in normal mice and mice with alloxan-induced diabetes mellitus, an experimental model of diabetes that exhibits a delay in the clearance of the dermatophyte, Trichophyton mentagrophytes (Tm). Our results demonstrated that inoculation of Tm into the footpads of normal mice increases the expression of TLR2 in CD115 + Ly6C high blood monocytes and, in hypoinsulinemic-hyperglycemic (HH) mice infected with Tm, the increased expression of TLR2 was exacerbated. To understand the role of TLR2 during the development of murine experimental deep dermatophytosis, we employed TLR2 knockout mice. Tm-infected TLR2 -/- and TLR2 +/+ wild-type mice exhibited similar control of deep dermatophytic infection and macrophage activity; however, TLR2 -/- mice showed a noteworthy increase in production of IFN-γ, IL-10, and IL-17, and an increased percentage of splenic CD25 + Foxp3 + Treg cells. Interestingly, TLR2 -/- HH-Tm mice exhibited a lower fungal load and superior organization of tissue inflammatory responses, with high levels of production of hydrogen peroxide by macrophages, alongside low TNF-α and IL-10; high production of IL-10 by spleen cells; and increased expansion of Tregs. In conclusion, we demonstrate that TLR2 diminishes the development of adaptive immune responses during experimental deep dermatophytosis and, in a diabetic scenario, acts to intensify a non-protective inflammatory response.

Background: Immune reconstitution inflammatory syndrome associated with dermatophytoses (tinea-IRIS) may cause considerable morbidity. Yet, it has been scarcely reported and is rarely considered in the differential diagnosis of HIV associated cutaneous lesions in Africa. If identified, it responds well to antifungals combined with steroids. We present two cases of suspected tinea-immune reconstitution inflammatory syndrome from a large HIV clinic in rural Tanzania., Cases Presentation: A first case was a 33 years-old female newly diagnosed HIV patient with CD4 count of 4 cells/μL (0 %), normal complete blood count, liver and renal function tests was started on co-formulated tenofovir/emtricitabine/efavirenz and prophylactic cotrimoxazole. Two weeks later she presented with exaggerated inflammatory hyperpigmented skin plaques with central desquamation, active borders and scratch lesions on the face, trunk and lower limbs. Tinea-IRIS was suspected and fluconazole (150 mg daily) and prednisolone (1 mg/Kg/day tapered down after 1 week) were given. Her symptoms subsided completely after 8 weeks of treatment, and her next CD4 counts had increased to 134 cells/μL (11 %). The second case was a 35 years-old female newly diagnosed with HIV. She had 1 CD4 cell/μL (0 %), haemoglobin 9.8 g/dl, and normal renal and liver function tests. Esophageal candidiasis and normocytic-normochromic anaemia were diagnosed. She received fluconazole, prophylactic cotrimoxazole and tenofovir/emtricitabine/efavirenz. Seven weeks later she presented with inflammatory skin plaques with elevated margins and central hyperpigmentation on the trunk, face and limbs in the frame of a good general recovery and increased CD4 counts (188 cells/μL, 6 %). Tinea-IRIS was suspected and treated with griseofulvin 500 mg daily and prednisolone 1 mg/Kg tapered down after 1 week, with total resolution of symptoms in 2 weeks., Conclusion: The two cases had advanced immunosuppression and developed de-novo exaggerated manifestation of inflammatory lesions compatible with tinea corporis and tinea facies in temporal association with antiretroviral treatment initiation and good immunological response. This is compatible with unmasking tinea-IRIS, and reminds African clinicians about the importance of considering this entity in the differential diagnosis of patients with skin lesions developing after antiretroviral treatment initiation.

Dermatophytoses are chronic fungal infections, the main causative agent of which is Trichophyton rubrum (T. rubrum). Despite their high occurrence worldwide, the immunological mechanisms underlying these diseases remain largely unknown. Here, we uncovered the C-type lectin receptors, Dectin-1 and Dectin-2, as key elements in the immune response to T. rubrum infection in a model of deep dermatophytosis. In vitro, we observed that deficiency in Dectin-1 and Dectin-2 severely compromised cytokine production by dendritic cells. In vivo, mice lacking Dectin-1 and/or Dectin-2 showed an inadequate pro-inflammatory cytokine production in response to T. rubrum infection, impairing its resolution. Strikingly, neither adaptive immunity nor IL-17 response were required for fungal clearance, highlighting innate immunity as the main checkpoint in the pathogenesis of T. rubrum infection., (© The Author(s) 2016.)

Chronic mucocutaneous or invasive fungal infections are generally the result of primary or secondary immune dysfunction. Patients with autosomal recessive CARD9 mutations are also predisposed to recurrent mucocutaneous and invasive fungal infections with Candida spp., dermatophytes (e.g., Trichophyton spp.) and phaeohyphomycetes (Exophiala spp., Phialophora verrucosa). We study a consanguineous family of Turkish origin in which three members present with distinct clinical phenotypes of chronic mucocutaneous and invasive fungal infections, ranging from chronic mucocutaneous candidiasis (CMC) in one patient, treatment-resistant cutaneous dermatophytosis and deep dermatophytosis in a second patient, to CMC with Candida encephalitis and endocrinopathy in a third patient. Two patients consented to genetic testing and were found to have a previously reported homozygous R70W CARD9 mutation. Circulating IL-17 and IL-22 producing T cells were decreased as was IL-6 and granulocyte/macrophage colony-stimulating factor (GM-CSF) secretion upon stimulation with Candida albicans. Patients with recurrent fungal infections in the absence of known immunodeficiencies should be analyzed for CARD9 gene mutations as the cause of fungal infection predisposition.

This paper reviews the developments that have occurred in the field of human genetics of infectious diseases from the second half of the 20th century onward. In particular, it stresses and explains the importance of the recently described monogenic inborn errors of immunity underlying resistance or susceptibility to specific infections. The monogenic component of the genetic theory provides a plausible explanation for the occurrence of severe infectious diseases during primary infection. Over the last 20 y, increasing numbers of life-threatening infectious diseases striking otherwise healthy children, adolescents, and even young adults have been attributed to single-gene inborn errors of immunity. These studies were inspired by seminal but neglected findings in plant and animal infections. Infectious diseases typically manifest as sporadic traits because human genotypes often display incomplete penetrance (most genetically predisposed individuals remain healthy) and variable expressivity (different infections can be allelic at the same locus). Infectious diseases of childhood, once thought to be archetypal environmental diseases, actually may be among the most genetically determined conditions of mankind. This nascent and testable notion has interesting medical and biological implications.

A 31-year-old immunocompetent male who presented with a 4-year history of extensive erythematous and scaly plaques involving the abdomen, gluteal and inguen regions with concomitant tinea pedis and onychomycosis is described. Diagnosis was based on positive mycological examination and positive histopathologic examination. Species identification was performed by growth on Sabouraud dextrose agar and by sequencing of the internal transcribed spacer regions of the rDNA region. The pathogen identified was Trichophyton rubrum. The same fungal species was cultured from his abdominal, gluteal, foot and toenail. A combination therapy with systemic terbinafine and topically applied terbinafine cream was successful. A 1-year follow-up did not show any recurrence of infection.

Dermatophytosis are one of the most common fungal infections in the world. They compromise keratinized tissues and the main etiological agent is Trichophyton rubrum. Macrophages are key cells in innate immunity and prominent sources of IL-1β, a potent inflammatory cytokine whose main production pathway is by the activation of inflammasomes and caspase-1. However, the role of inflammasomes and IL-1 signaling against T.rubrum has not been reported. In this work, we observed that bone marrow-derived macrophages produce IL-1β in response to T.rubrum conidia in a NLRP3-, ASC- and caspase-1-dependent fashion. Curiously, lack of IL-1 signaling promoted hyphae development, uncovering a protective role for IL-1β in macrophages. In addition, mice lacking IL-1R showed reduced IL-17 production, a key cytokine in the antifungal defense, in response to T.rubrum. Our findings point to a prominent role of IL-1 signaling in the immune response to T.rubrum, opening the venue for the study of this pathway in other fungal infections.

Dermatophytes are fungi responsible for causing superficial infections. In patients with diabetes mellitus (DM), dermatophytosis is usually more severe and recurrent. In the present study, we aimed to investigate the influence of short and long term hypoinsulinemia-hyperglycemia (HH) during experimental infection by Trichophyton mentagrophytes as well as alterations in the mononuclear phagocytes. Our results showed two distinct profiles of fungal outcome and immune response. Short term HH induced a discrete impaired proinflammatory response by peritoneal adherent cells (PAC) and a delayed fungal clearance. Moreover, long term HH mice showed low and persistent fungal load and a marked reduction in the production of TNF-α by PAC. Furthermore, while the inoculation of TM in non-HH mice triggered high influx of Gr1(+) monocytes into the peripheral blood, long term HH mice showed low percentage of these cells. Thus, our results demonstrate that the time of exposure of HH interferes with the TM infection outcome as well as the immunobiology of mononuclear phagocytes, including fresh monocyte recruitment from bone marrow and PAC activity.

Dermatophytes are the most common agents of superficial mycoses that are caused by mold fungi. Trichophyton rubrum is the most common pathogen causing dermatophytosis. The immunology of dermatophytosis is currently poorly understood. Recently, our group investigated the interaction of T. rubrum conidia with peritoneal mouse macrophages. We found that macrophages phagocytose T. rubrum conidia resulted in a down-modulation of class II major histocompatibility complex (MHC) antigens and in the expression of co-stimulatory molecules. Furthermore, it induced the production of IL-10, and T. rubrum conidia differentiated into hyphae that grew and killed the macrophages after 8 hrs of culture. This work demonstrated that dendritic cells (DCs) and macrophages, from patients or normal individuals, avidly interact with pathogenic fungus T. rubrum. The dermatophyte has two major receptors on human monocyte-derived DC: DC-SIGN and mannose receptor. In contrast macrophage has only mannose receptor that participates in the phagocytosis or bound process. Another striking aspect of this study is that unlike macrophages that permit rapid growth of T. rubrum, human DC inhibited the growth and induces Th activation. The ability of DC from patients to interact and kill T. rubrum and to present Ags to T cells suggests that DC may play an important role in the host response to T. rubrum infection by coordinating the development of cellular immune response.

Background: The number of household pets increased greatly during the twentieth century, with numbers of new pets (NP, i.e. any pets other than cats and dogs) rising especially sharply over the last decade., Patients and Methods: We first of all report the case of a female patient with eczema lesions on areas skin coming into contact with a ferret, with removal of the animal resulting in wound healing, followed by two patients presenting atypical polymorphous erythema reactions induced by dermatophytes present in their pet rat., Discussion: While the most common allergies are respiratory, allergic skin reactions, both immediate and delayed, may also result from contact with these new allergens. The animal itself or its environment may be the cause., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Majocchi's granuloma is a persistent supurative folliculitis, associated with a deep granulomatous reaction induced by dermatophytes. There are two clinical forms of Majocchi's granuloma: the superficial form that appears in healthy individuals after localized trauma; and the nodular form, which occurs in inmunocompromised patients. We present a case of nodular Majocchi's granuloma on the forearm of an immunocompetent patient. Microbiological culture and examination of a deep aspiration sample identified Trichophyton rubrum. Collecting a deep sample of tissue is essential in achieving a good diagnostic performance.

Background: Skin diseases characterize all stages of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) and contribute significantly to associated morbidity and mortality., Objectives: The aim of this study was to document the prevalences, patterns, and extents (severity) of skin diseases and their relationships with immunologic status in HIV/AIDS patients., Methods: A total of 140 HIV/AIDS patients in different stages of HIV infection and 140 controls were recruited. Skin diseases were documented and CD4+ cell counts determined in all subjects. Severity was assessed according to the body surface area affected (using the Wallace rule of nines and the rule of palm) for lesions that tended to be widespread. The number of digits involved was counted for lesions involving the nails. Intensity of pain was graded for specific conditions such as herpes zoster. Chi-squared statistics and Pearson correlations were determined., Results: Mean±standard deviation age was 35.04±8.83 years in the patient group and 32.21±8.30 years in the control group. The prevalences and patterns of skin diseases in HIV/AIDS patients were similar to those reported in previous studies. Most commonly found dermatoses were oral candidiasis (n=28, 20.0%), pruritic papular eruption (n=27, 19.3%), xeroderma (n=23, 16.4%), dermatophytosis (n=22, 15.7%), and fluffy hair (n=19, 13.6%). The presence of specific skin lesions represented a better correlate with immunosuppression than cutaneous extents. However, the extents of viral warts and multiple blue–black nails correlated significantly with CD4+ cell count. The presence of a lighter hair color phenotype signifies a lower CD4+ cell count than a softer hair phenotype., Conclusions: The presence of specific skin lesions correlates more strongly with a low CD4+ cell count than does the extent of their distribution, except in cases of viral warts. The presence of and higher numbers of nails affected with blue–black nail hyperpigmentation suggest severe immunosuppression.

Trichophyton rubrum is the main etiological agent of dermatophytosis, an infection of the skin that affects millions of people worldwide. In this study, we developed a murine model of the dermatophytosis caused by T. rubrum in which C57BL/6 wild-type, interleukin (IL)-12(-/-), and interferon-gamma (IFN-γ(-/-)) mice were inoculated with 1 × 10(6) conidia/animal. The fungal burden, myeloperoxidase and N-acetylglucosaminidase activities, cytokine and chemokine profiles, and histopathology of the skin were evaluated on the seventh and fourteenth days post infection. Phagocytic indices, intracellular proliferation rates, and oxidative bursts generated by macrophages from WT and IFN-γ(-/-) mice were determined. On day 7 post infection, higher fungal burdens were observed comparison with burdens on day 14 post infection. The IL-12(-/-) and IFN-γ(-/-) mice showed higher fungal burdens on the skin and lower levels of IL-1β. Conversely, the WT mice showed lower fungal burdens with higher production of TNF-α, IL-1β, and chemokine ligand 1/keratinocyte chemoattractant (CXCL1/KC). The macrophages from WT mice proved to be more efficient at engulfing and killing T. rubrum conidia through the production of reactive oxygen species. The results show that our model is a useful tool for understanding the pathogenesis of dermatophytosis caused by T. rubrum and that IL-12 and IFN-γ are pivotal in controlling the infection through the recruitment and activation of neutrophils and macrophages.

Bovine ringworm caused by Trichophyton verrucosum is a notifiable disease in Norway. New infected herds are reported to the Norwegian Food Safety Authority. To limit spread of the disease, restrictions are imposed on holdings including access to common pastures and sale of live animals. Bovine ringworm has been endemic in the Norwegian dairy population for decades. Since 1980 a vaccine (Bovilis Ringvac LTF-130, Merck Animal Health) has been available. The vaccine contains an attenuated strain of T. verrucosum and stimulates humoral and cellular immune responses conferring protection. Efficacy and safety of the vaccine have been evaluated in experimental and field studies. Vaccination campaigns in densely populated counties have contributed to a substantial decrease in number of ringworm outbreaks. The annual incidence of new infected herds decreased from 1.7% in 1980 to 0.043% in 2004. Few herds remained with restrictions and a "mopping up" project was established to offer assistance specifically to these holdings. A milestone was achieved in 2009; no new herds with cases of clinical ringworm caused by T. verrucosum were reported to the authorities. By end of 2012, there are only two herds with restrictions. Vaccination during the last 30 years has been a key control measure in the effort to prevent disease outbreaks and eradicate bovine ringworm in Norway., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A 10-month-old boy with congenital lamellar ichthyosis presented with a chronic Trichophyton rubrum infection. There was no history of atopy or immunosuppression, and examination revealed high total immunoglobulin E (IgE) with a positive specific IgE for T. rubrum. Multiple treatments with fluconazole were necessary to control the infection. T. rubrum is present worldwide and is responsible for the vast majority of chronic dermatophytosis. Lamellar ichthyosis is a risk factor for chronic dermatophytosis because of excessive keratin and the barrier defect. A delayed-type hypersensitivity reaction to T. rubrum is associated with cure, whereas immediate hypersensitivity and IgE are not protective and may lead to chronic infection. Atopy and the Th2 profile therefore seem to be associated with chronic dermatophytosis. The association between ichthyosis and atopy is well documented. T. rubrum also has an interesting ability to evade immunity, which helps explain the chronic infection. Finally, in ichthyosis, it is likely that fluconazole has difficulty penetrating the acanthotic stratum corneum, which explains treatment failure. We report this case to alert clinicians to the possible association between lamellar ichthyosis and chronic dermatophytosis and to report the difficulties of management., (© 2013 Wiley Periodicals, Inc.)

Dermatophytes invade the stratum corneum of the skin and other keratinized tissues such as hair and nails, and Trichophyton rubrum causes approximately 80% of cutaneous mycoses in humans. To evaluate the cellular immune response of patients with extensive dermatophytosis caused by T. rubrum, we evaluated lymphocyte populations, the lymphoproliferative response to: phytohaemagglutinin (PHA); anti-CD3 (OKT3); and pokeweed mitogen (PWM), Candida sp. (CMA), an extract of T. rubrum, and the main fungal epitope TriR2 (T). We also evaluated interleukin (IL)-4, IL-10, IL-12 and IFN-γ after stimulation by PHA, CMA and TriR2. The immunophenotyping showed no differences between patients and controls. The lymphoproliferation test showed significant differences between the groups stimulated by PWM and CMA, as well as against TriR2, being significantly higher for the control group. Conversely, there were similar results for the groups after stimulation by the extract. The cytokines' quantification showed a significant difference between the groups only for IFN-γ stimulated by PHA and TriR2. We can conclude that the fungal extract can stimulate lymphoproliferation by both groups' lymphocytes. However, the response to Tri r2 was more specific. We showed that some patients with extensive dermatophytosis have normal cellular response, recognising both the extract and TriR2., (© 2012 Blackwell Verlag GmbH.)

Research of human T lymphotropic virus type I (HTLV-1)-associated diseases is mostly focused on inflammatory and lymphoproliferative disorders. However, the immunosuppressive consequences of HTLV-1 infection are frequently ignored. In developing countries where exposure to parasitic and other tropical diseases is frequent, the burden of disease is significantly increased by opportunistic infections. Regulatory T cells (Tregs) are a CD4 T-cell subset capable of suppressing effector responses. During HTLV-1 infection, CD4+Foxp3+ cells are increased in HTLV-1-associated leukaemia/lymphoma (ATLL) as well as in non-leukaemic presentations. However, controversy exists regarding the actual regulatory function of these cells. In this report, we present two cases of HTLV-1 ATLL complicated by parasitic organisms and we provide a brief review of the literature regarding FoxP3+ regulatory T cells and their role as a possible mechanism for the immunosuppressive manifestations that take place during HTLV-1 infection.

Recognizing the invasive potential of the dermatophytes and understanding the mechanisms involved in this process will help with disease diagnosis and with developing an appropriate treatment plan. In this report, we present the histopathological, microbiological and immunological features of a model of invasive dermatophytosis that is induced by subcutaneous infection of Trichophyton mentagrophytes in healthy adult Swiss mice. Using this model, we observed that the fungus rapidly spreads to the popliteal lymph nodes, spleen, liver and kidneys. Similar to the human disease, the lymph nodes were the most severely affected sites. The fungal infection evoked acute inflammation followed by a granulomatous reaction in the mice, which is similar to what is observed in patients. The mice were able to mount a Th1-polarized immune response and displayed IL-10-mediated immune regulation. We believe that the model described here will provide valuable information regarding the dermatophyte-host relationship and will yield new perspective for a better understanding of the immunological and pathological aspects of invasive dermatophytosis., (Copyright © 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.)

Purpose: Superficial dermatophytosis is quite commonly seen in patients with adult T-cell leukemia/lymphoma (ATLL), as approximately 50% of the patients develop cutaneous mycotic infections. Because superficially infected fungi in the stratum corneum of the epidermis cannot directly contact with T cells infiltrating in the upper dermis, some perturbation of epidermal innate immunity has been postulated. Interleukin (IL)-17-producing helper T cells (Th17) can induce the keratinocyte production of antimicrobial peptides such as human β defensin (HBD)-2 and LL-37, which play an essential role in cutaneous innate immunity., Experimental Design: We investigated the frequency of circulating Th17 cells, serum levels of cytokines, and epidermal expression of HBD-1, 2, 3, and LL-37 in ATLL patients with or without superficial dermatophytosis., Results: The frequency of peripheral Th17 cells and the serum level of IL-17 was significantly decreased in ATLL patients, whereas the serum IL-10 and TGF-β1 levels were increased as compared with healthy controls. Furthermore, ATLL patients with dermatophytosis had higher IL-10 and TGF-β1 levels and lower IL-17 levels than did those without dermatophytosis. Immunohistochemical study revealed that the epidermal expression of both HBD-2 and LL-37 were significantly lower in ATLL patients with dermatophytosis than in non-ATLL patients with dermatophytosis., Conclusions: Taken together, these results suggest that the keratinocyte production of antimicrobial peptides promoted by Th17 cells is reduced in ATLL patients, leading to the perturbed innate immunity and the frequent occurrence of superficial dermatophytosis.

Background: The association of dermatophytes with atopic patients and improvement in allergic signs with antifungal treatment suggest a possible link between chronic infection and atopy., Objective: The purpose of this study was to determine skin reactivity and serum IgE antibody responses in patients with chronic and acute dermatophytosis., Methods: One hundred and sixty-three patients with chronic dermatophytosis, 35 patients with acute dermatophytosis, 41 atopic patients and 49 healthy subjects were enrolled in this study. Sensitization to Trichophyton mentagrophytes (T. mentagrophytes), Candida albicans and Aspergillus fumigatus antigens has been evaluated in patients by skin prick test (SPT) and by the presence of specific IgE antibody in enzyme-linked immuno-sorbent assay (ELISA)., Results: Positive immediate hypersensitivity (IH) reactions were obtained in 95.1% of the atopic patients with chronic infection for T. mentagrophytes, representing a significant difference from other patient groups (P < 0.05). Specificanti-T. mentagrophytes IgE antibodies were detected in atopic patients with chronic (65.9%) and acute (50%) dermatophytosis, while none of the atopic subjects had positive IgE reactions to T. mentagrophytes., Conclusion: The results showed significant higher positive IH and specific anti-T. mentagrophytes IgE responses in atopic patients with chronic dermatophytosis than the other groups.