Production of T-helper cell subsets and cytokines by lymphocytes from patients with chronic mucocutaneous candidiasis

Exploring the clinical features and risk factors for children tinea capitis complicated with allergic diseases

BACKGROUND

Tinea capitis, atopic dermatitis and allergic rhinitis are the most common disorders endured by prepubescent children. Dermatophyte infections have been linked to allergic disorders, such as increased sensitivity to dermatophytes in patients with atopic dermatitis.

OBJECTIVES

To explore the correlation between tinea capitis and allergic diseases in children and to analyse their risk factors.

METHODS

This study monitored epidemiological changes in childhood tinea capitis and risk factors for whom with allergic disease in a single centre in three consecutive five-year intervals by reviewing clinical data and multivariate logistic data analysis.

RESULTS

Between 2007 and 2022, there were 127 children patients with tinea capitis, the mean age was 4.83 years, and the male-to-female ratio was 1.76:1. Zoophilic Microsporum canis and Trichophyton mentagrophytes were the most prevalent pathogens, and the proportions remained relatively constant every 5 years. There were 34 (26.8%) children with tinea capitis complicated with allergic disease, among them 14 children with atopic dermatitis/eczema, 13 with allergic rhinitis, 8 urticaria, 6 food allergies and 1 allergic asthma. Male, kerion, zoophilic species infections and animal contact history were prevalent features in allergic disease combined with tinea capitis. Patients with tinea capitis plus allergic disease mostly had a family history with similar complications.

CONCLUSION

M. canis and T. mentagrophytes were the most prevalent pathogens of tinea capitis in the last 15 years; atopic dermatitis/eczema and allergic rhinitis were the most frequently associated allergic diseases. Male, kerion, zoophilic pathogen and animal contact history are risk factors.

A study on the risk of fungal infection with tofacitinib (CP-690550), a novel oral agent for rheumatoid arthritis

Tofacitinib (CP-690550), an oral Janus kinase inhibitor, has shown significant efficacy in the treatment of rheumatoid arthritis through blocking the signaling pathways of pro-inflammatory cytokines. However, recent evidence suggests that long-term tofacitinib treatment is associated with increased risk of infection (e.g. tuberculosis) in patients. In the present study, we illustrate that tofacitinib administration significantly reduced the survival rate of mice given lethal or sub-lethal dose challenge with Candida albicans. This was related to the ability of tofacitinib to reverse TNFα- and IFNγ-enhanced candidacidal activity of murine polymorph nuclear cells (PMNs) and also to suppress chemokine CXCL5 expression and PMN infiltration in the infected tissues of mice. More importantly, tofacitinib significantly antagonized the ability of TNFα, IFNγ and GM-CSF to boost human PMNs in phagocytosis and direct killing of C. albicans in vitro. It also down-regulated reactive oxygen production and neutrophil extracellular trap formation by human PMNs stimulated with yeast-derived β-glucans in the presence of TNFα, IFNγ or GM-CSF. Our data emphasizes a significantly increased risk for opportunistic fungal infection associated long-term tofacitinib treatment in humans, likely through antagonizing the PMN-boosting effect of pro-inflammatory cytokines.

Immunological and histopathological characterization of cutaneous candidiasis

Chronic mucocutaneous candidiasis constitutes a heterogeneous group of syndromes, characterized by non-invasive infection of the skin, nails and mucosal membranes by the fungus Candida spp. Although symptoms are heterogeneous, in all cases there is a reduction in protective cytokines, favouring the development of disease. The normal role of cytokines in skin lesions is not well understood. The present study aimed to investigate the progression of disease, understand specific cellular and molecular components involved in immunity to Candida albicans and determine the balance between pro- and anti-inflammatory cytokines over the course of cutaneous infection in immunocompetent mice. BALB/c mice (five per group) were inoculated with 5 × 10(6)C. albicans pseudohyphae in the deep dermis of the paw and analysed over 1-14  days post-infection. The contralateral paws were used for negative controls. Haematoxylin and eosin staining of skin sections during C. albicans infection was performed to analyse structural modifications to the epidermis such as hyperplasia, and infiltration of neutrophils and fibroblasts in the dermis. The cytokine populations were determined by capture ELISA using popliteal lymph node tissue. Pro-inflammatory cytokines (IL-6, TNF-α, IL-12, IFN-γ and IL-17) were detected at significant levels during the initial phase of cutaneous infection and correlated with the rapid elimination of C. albicans. Anti-inflammatory cytokines (IL-13, IL-4, IL-10 and transforming growth factor-β) were detected on day 4 post-infection, and prevented exacerbation of inflammation and participated in healing of lesions. Thus, a balance between pro- and anti-inflammatory cytokines was fundamental for the resolution of infection. Importantly, these findings broaden our understanding of the immune mechanisms involved in chronic cutaneous candidiasis.

Candida glabrata: new tools and technologies-expanding the toolkit

In recent years, there has been a noticeable rise in fungal infections related to non-albicans Candida species, including Candida glabrata which has both intrinsic resistance to and commonly acquired resistance to azole antifungals. Phylogenetically, C. glabrata is more closely related to the mostly non-pathogenic model organism Saccharomyces cerevisiae than to other Candida species. Despite C. glabrata's designation as a pathogen by Wickham in 1957, relatively little is known about its mechanism of virulence. Over the past few years, technology to analyse the molecular basis of infection has developed rapidly, and here we briefly review the major advances in tools and technologies available to explore and investigate the virulence of C. glabrata that have occurred over the past decade.

Evaluation of proliferation and cytokines production by mitogen-stimulated bovine peripheral blood mononuclear cells

This in vitro study was conducted to evaluate lymphocyte blastogenic and cytokine production by bovine peripheral blood mononuclear cells (PBMCs) stimulated with phytohemagglutinin (PHA), pokeweed mitogen (PWM) and concanavalin A (Con A) mitogens, by using tetrazolium salt and ELISA tests, respectively. The results presented that Interleukin-2 (IL-2), IL-4, IL-5, IL-10, IL-17 and IFN-γ production in response to PWM mitogens was the highest and Con A the lowest amount and the median values of three mitogens were in the following order: PWM > PHA > Con A > cell control. In the case of IL-6, the production of this cytokine was the same amount for PWM and Con A and a lower amount for PHA stimulation. The results of this study not only showed a normal range for the production of these cytokines from PBMCs that were affected by mitogens, but it demonstrated that the bovine immune system at 2.5 to 3 months was post-natally matured enough to mount an effective immune response to mitogens as well as specific antigens.

Applying Convergent Immunity to Innovative Vaccines Targeting Staphylococcus aureus

Recent perspectives forecast a new paradigm for future “third generation” vaccines based on commonalities found in diverse pathogens or convergent immune defenses to such pathogens. For Staphylococcus aureus, recurring infections and a limited success of vaccines containing S. aureus antigens imply that native antigens induce immune responses insufficient for optimal efficacy. These perspectives exemplify the need to apply novel vaccine strategies to high-priority pathogens. One such approach can be termed convergent immunity, where antigens from non-target organisms that contain epitope homologs found in the target organism are applied in vaccines. This approach aims to evoke atypical immune defenses via synergistic processes that (1) afford protective efficacy; (2) target an epitope from one organism that contributes to protective immunity against another; (3) cross-protect against multiple pathogens occupying a common anatomic or immunological niche; and/or (4) overcome immune subversion or avoidance strategies of target pathogens. Thus, convergent immunity has a potential to promote protective efficacy not usually elicited by native antigens from a target pathogen. Variations of this concept have been mainstays in the history of viral and bacterial vaccine development. A more far-reaching example is the pre-clinical evidence that specific fungal antigens can induce cross-kingdom protection against bacterial pathogens. This trans-kingdom protection has been demonstrated in pre-clinical studies of the recombinant Candida albicans agglutinin-like sequence 3 protein (rAls3) where it was shown that a vaccine containing rAls3 provides homologous protection against C. albicans, heterologous protection against several other Candida species, and convergent protection against several strains of S. aureus. Convergent immunity reflects an intriguing new approach to designing and developing vaccine antigens and is considered here in the context of vaccines to target S. aureus.

The immune interplay between the host and the pathogen in Aspergillus fumigatus lung infection

The interplay between Aspergillus fumigatus and the host immune response in lung infection has been subject of studies over the last years due to its importance in immunocompromised patients. The multifactorial virulence factors of A. fumigatus are related to the fungus biological characteristics, for example, structure, ability to grow and adapt to high temperatures and stress conditions, besides capability of evading the immune system and causing damage to the host. In this context, the fungus recognition by the host innate immunity occurs when the pathogen disrupts the natural and chemical barriers followed by the activation of acquired immunity. It seems clear that a Th1 response has a protective role, whereas Th2 reactions are often associated with higher fungal burden, and Th17 response is still controversial. Furthermore, a fine regulation of the effector immunity is required to avoid excessive tissue damage associated with fungal clearance, and this role could be attributed to regulatory T cells. Finally, in this work we reviewed the aspects involved in the complex interplay between the host immune response and the pathogen virulence factors, highlighting the immunological issues and the importance of its better understanding to the development of novel therapeutic approaches for invasive lung aspergillosis.

Inborn errors of human IL-17 immunity underlie chronic mucocutaneous candidiasis

PURPOSE OF REVIEW

Chronic mucocutaneous candidiasis (CMC) is characterized by recurrent or persistent symptomatic infection of the nails, skin and mucosae mostly by Candida albicans. CMC is common in patients with profound primary T-cell immunodeficiency, who often display multiple infectious and autoimmune diseases. Patients with syndromic CMC, including autosomal dominant hyper IgE syndrome (AD-HIES) and autosomal recessive autoimmune polyendocrinopathy syndrome type I (APS-I), display fewer other infections. Patients with isolated CMC (CMCD) rarely display any other severe disease. We review here recent progress in the genetic dissection of these three types of inherited CMC.

RECENT FINDINGS

Low IL-17 T-cell proportions were reported in patients with AD-HIES bearing heterozygous STAT3 mutations, prone to CMC and staphylococcal diseases, and in a kindred with autosomal recessive CARD9 deficiency, prone to CMC and other fungal infections. High levels of neutralizing autoantibodies against IL-17 cytokines were documented in patients with APS-I presenting with CMC as their only infectious disease. The first three genetic causes of CMCD were then reported: autosomal recessive IL-17RA and autosomal dominant IL-17F deficiencies and autosomal dominant STAT1 gain-of-function, impairing IL-17-producing T-cell development.

SUMMARY

Inborn errors of human IL-17 immunity underlie CMC. Impaired IL-17 immunity may therefore account for CMC in other settings, including patients with acquired immunodeficiency.

Inborn errors of mucocutaneous immunity to Candida albicans in humans: a role for IL-17 cytokines?

The various clinical manifestations of chronic mucocutaneous candidiasis (CMC) often result from acquired T-cell immunodeficiencies. More rarely, CMC results from inborn errors of immunity, the recent dissection of which has shed light on the molecular mechanisms of mucocutaneous immunity to Candida albicans. CMC may accompany various other infectious diseases in patients with almost any broad and profound T-cell primary immunodeficiency. By contrast, CMC is one of the few key infections in patients with autosomal dominant hyper IgE syndrome (mutations in STAT3), and in rare patients with autosomal recessive predisposition to mucocutaneous and invasive fungal infections (mutation in CARD9). In patients with mutations in STAT3 and CARD9, the development of IL-17-producing T cells is impaired. Moreover, CMC is the principal, if not only, infection in patients with autosomal recessive autoimmune polyendocrinopathy syndrome-I (mutations in AIRE). Patients with this condition have high titers of neutralizing autoantibodies (auto-Abs) against the IL-17 cytokines IL-17A, IL-17F, and IL-22. Collectively, these data suggest that human IL-17A, IL-17F, and IL-22 are essential for mucocutaneous immunity to C. albicans. They also suggest that the distinct syndrome of isolated CMC, without auto-immunity or other infections, may be caused by inborn errors of IL-17 immunity.

Flow cytometry study of blood cell subtypes reflects autoimmune and inflammatory processes in autoimmune polyendocrine syndrome type I

Autoimmune polyendocrine syndrome type I (APS I) is a recessive disorder caused by mutations in the autoimmune regulator (AIRE) gene. AIRE is expressed in medullary epithelial cells where it activates transcription of organ-specific proteins in thymus, thereby regulating autoimmunity. Patients with APS I have, in addition to autoimmune manifestations in endocrine organs, also often ectodermal dystrophies and chronic mucocutaneous candidiasis. The aim of this study was to characterize immune cell subpopulations in patients with APS I and their close relatives. Extensive blood mononuclear cell immunophenotyping was carried out on 19 patients with APS I, 18 first grade relatives and corresponding sex- and age-matched healthy controls using flow cytometry. We found a significant relative reduction in T helper cells coexpressing CCR6 and CXCR3 in patients with APS I compared to controls (mean = 4.10% versus 5.94% respectively, P = 0.035). The pools of CD16(+) monocytes and regulatory T cells (Tregs) were also lower in patients compared with healthy individuals (mean = 15.75% versus 26.78%, P = 0.028 and mean = 4.12% versus 6.73%, P = 0.029, respectively). This is the first report describing reduced numbers of CCR6(+)CXCR3(+) T helper cells and CD16(+) monocytes in patients with APS I We further confirm previous findings of reduced numbers of Tregs in these patients.

Impaired dendritic cell maturation and cytokine production in patients with chronic mucocutanous candidiasis with or without APECED

Patients with chronic mucocutaneous candidiasis (CMC) suffer persistent infections with the yeast Candida. CMC includes patients with autoimmune regulator (AIRE) gene mutations who have autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), and patients without known mutations. CMC patients have dysregulated cytokine production, and dendritic cells (DCs), as central orchestrators, may underlie pathogenic disease mechanisms. In 29 patients with CMC (13 with APECED) and controls, we generated monocyte-derived DCs, stimulated them with Candida albicans, Toll-like receptor-2/6 ligand and lipopolysaccharide to assess cytokine production [interleukin (IL)-12p70, IL-23, interferon (IFN)-gamma, IL-2, tumour necrosis factor (TNF)-alpha, IL-6, transforming growth factor-beta, IL-10, IL-5, IL-13] and cell-surface maturation marker expression (CD83, CD86, human leucocyte antigen D-related). In both APECED and non-APECED CMC patients, we demonstrate impairment of DC function as evidenced by altered cytokine expression profiles and DC maturation/activation: (1) both groups over-produce IL-2, IFN-gamma, TNF-alpha and IL-13 and demonstrate impaired DC maturation. (2) Only non-APECED patients showed markedly decreased Candida-stimulated production of IL-23 and markedly increased production of IL-6, suggesting impairment of the IL-6/IL-23/T helper type 17 axis. (3) In contrast, only APECED patients showed DC hyperactivation, which may underlie altered T cell responsiveness, autoimmunity and impaired response to Candida. We demonstrate different pathogenic mechanisms on the same immune response pathway underlying increased susceptibility to Candida infection in these patients.

Patients with chronic mucocutaneous candidiasis exhibit reduced production of Th17-associated cytokines IL-17 and IL-22

Chronic mucocutaneous candidiasis (CMC) constitutes a selective inability to clear infection with the yeast Candida, resulting in persistent debilitating inflammation of skin, nails, and mucous membranes. The underlying defect is unknown. Only recently, IL-17-producing T cells have been reported to be involved in clearing Candida infections. In order to characterize T cellular immune response to Candida, we analyzed T-cell cytokine secretion to Candida antigen and mitogenic stimuli in CMC patients, immunocompetent patients suffering from acute Candida infection, and healthy volunteers. Peripheral blood mononuclear cells (PBMCs) from CMC patients produced significantly lower amounts of IL-17 and IL-22 mRNA and protein when stimulated with Candida albicans or mitogen in vitro compared with that in matched healthy individuals. Additionally, PBMCs from immunocompetent Candida-infected patients secreted more IL-17 and IL-22 than those of both CMC patients and healthy, non-infected controls. Flow cytometry revealed a decreased number of CCR6+ IL-17-producing T cells in CMC patients, whereas the amount of CCR6+/CCR4+ cells was not altered. Levels of differentiating cytokines for human Th17 cells, IL-1beta and IL-6, tended to be higher in CMC patients. The inability to clear C. albicans in CMC patients could be due to a defect in the immune response of IL-17-producing T cells.

Primary immune deficiency disorders presenting as autoimmune diseases: IPEX and APECED

BACKGROUND

Several primary immune deficiency disorders are associated with autoimmunity and malignancy, suggesting a state of immune dysregulation. The concept of immune dysregulation as a direct cause of autoimmunity in primary immune deficiency disorders (PIDDs) has been strengthened by the recent discovery of distinct clinical entities linked to single-gene defects resulting in multiple autoimmune phenomena including immune dysregulation, polyendocrinopathy, enteropathy and X-linked (IPEX) syndrome, and autoimmune polyendocrinopathy, candidiasis and ectodermal dystrophy (APECED) syndrome.

CONCLUSION

Reviewing recent advances in our understanding of the small subgroup of PIDD patients with defined causes for autoimmunity may lead to the development of more effective treatment strategies for idiopathic human autoimmune diseases.

Immunophenotypic characterisation of peripheral blood lymphocytes in autoimmune polyglandular syndrome type 1: clinical study and review of the literature

Autoimmune endocrinopathies are characterised by an increased number of peripheral blood lymphocytes (PBL) expressing activation/ memory markers on their surface. The aim of this study was to determine whether a similar finding could be detected in a group of 11 paediatric and young adult patients suffering from autoimmune polyglandular syndrome type 1 (APS1), also called autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), as very few data have previously been reported in this field. The control group was made up of 11 sex- and age-matched healthy subjects. Fifteen lymphocyte subsets were compared, in terms of percentage and absolute number, and statistical analysis was performed by the Mann-Whitney test. Measurement of T (CD3+), B (CD19+), natural killer (NK, CD3-CD16/56+), CD4+ and CD8+ T lymphocytes showed that patients with APS1 had a higher percentage and absolute count of T lymphocytes: this was entirely due to the statistically larger CD3+CD4+ fraction. Patients with APS1 also had slightly fewer B and NK lymphocytes, but the difference was negligible. Comparison of CD4+ subpopulations bearing activation and naive/memory antigens (marked by CD69, CD25, anti-HLA-DR, CD45RA and CD45RO) showed that patients with APS1 had generally larger percentages and absolute counts of these subsets: however, only the percentage and absolute size of the CD4+CD25+ subset (p = 0.0354 and p = 0.0151, respectively), and the absolute number of the CD4+ anti-HLA-DR+ and CD4+ CD45RO+ subsets (p = 0.0193 and p = 0.0209, respectively) were significantly higher. Interestingly, patients with APS1 also had significantly fewer CD8+CD11b+ and CD3-CD8+ cells. In conclusion, PBL distribution in APS1 resembles that of other autoimmune diseases. Further studies are needed to confirm and possibly extend these data.

New perspectives on the immunology of chronic mucocutaneous candidiasis

Chronic mucocutaneous candidiasis is a primary immune deficiency presenting as an inability to clear fungal infections and consequently as persisting and recurring infections of the skin and mucous membranes with yeasts, mostly Candida albicans. Chronic mucocutaneous candidiasis is a heterogeneous clinical syndrome which usually presents in childhood and can have an autosomal recessive, dominant or sporadic mode of inheritance. Most chronic mucocutaneous candidiasis patients also develop accompanying endocrine and inflammatory disorders that suggest an underlying deregulation of the immune system. It has long been recognized that protection from mucocutaneous candidiasis relies on cell-mediated immunity and studies on animal models have highlighted the essential role of type 1 cytokines in protection against Candida spp. Recent data in patients with chronic mucocutaneous candidiasis have documented altered patterns of cytokine production in response to Candida spp. with decreased production of some but not all type 1 cytokines and increased levels of interleukin-10. The defect underlying altered cytokine production remains unknown but studies are in progress addressing the putative role of dendritic cells and pattern recognition receptors in directing cytokine responses. These novel insights into immune mechanisms responsible for protection against Candida spp. are opening new possibilities of immunomodulation and vaccination that could prove beneficial in the management of chronic mucocutaneous candidiasis.

Characterization of the cellular immune function of patients with chronic mucocutaneous candidiasis

Chronic mucocutaneous candidiasis (CMC) is a rare syndrome characterized by persistent and refractory infections of the skin, nails and mucosal tissues by yeasts of the genus Candida. Defects in the cellular limb of the immune system are well documented in CMC patients, but non-specific immune defects, such as myeloperoxidase deficiency or phagocyte chemotaxis disorders, have also been described. Nonetheless, the underlying defect(s) remains poorly understood, and further studies are required. We studied eight CMC patients without endocrinopathies, who showed (i) low normal proliferative response to phytohaemagglutinin (PHA), (ii) partially defective response to pokeweed mitogen (PWM), and (iii) impaired response to Candida and PPD antigens. Furthermore, peripheral blood mononuclear cells (PBMC) from CMC patients produced lower levels of type-1 cytokines (IL-2 and interferon-gamma) in response to Candida antigens, compared with control individuals. Conversely, we did not observe an enhancement of IL-4 and IL-10 in the patients, suggesting that, even though Th1 cytokines are decreased, the Th2 response is not increased in CMC. Nevertheless, the synthesis of these cytokines was normal when induced by PHA. We also observed an increased antigen-induced apoptosis in lymphocytes from the patients compared with controls, and this applied both to Candida and PPD antigens. Lastly, innate immunity defects were investigated. We observed an impairment of natural killer activity against K-562 target cells in half of the studied patients. These findings corroborate the extensive clinical and laboratory variability of CMC, which requires further studies on a larger number of patients to be better understood.

Immunity to Candida albicans: Th1, Th2 cells and beyond

Resistance to Candida albicans infection in mice results from the development of T helper (Th) type 1 cell responses. Cytokines produced by Th1 cells activate macrophages and neutrophils to a candidacidal state. The development of Th2 responses underlines susceptibility to infection, because cytokines produced by Th2 cells inhibit Th1 development and deactivate phagocytic effector cells. With the recognition of the reciprocal influences between innate and adaptive Th immunity, it appears that the coordinated action of these two lines of immune defense is required to efficiently oppose the infectivity of the fungus and to determine its lifelong commensalism at the mucosal level.

Early resistance of interleukin-10 knockout mice to acute systemic candidiasis

In contrast to immunocompetent controls, interleukin-10 (IL-10) knockout (KO) mice eliminated an experimental intravenous inoculation with Candida albicans from their kidneys. Improved clearance of C. albicans from the kidneys of IL-10 KO mice was evident at 24 h after intravenous challenge with the fungus. Conversely, mice with a deletion of the IL-4 cytokine gene were more susceptible to systemic candidiasis than were immunocompetent controls. The hyperresistance of IL-10 KO mice to acute systemic candidiasis did not seem to correlate with nitric oxide-mediated immunity, but rather, it appeared to be associated with more efficient effector function of innate cells, possibly neutrophils. In support of the latter hypothesis, we observed that neutrophils from IL-10 KO mice were more efficient at killing C. albicans blastoconidia and hyphae than were neutrophils from immunocompetent control mice. Neither IL-10 KO nor IL-4 KO mice that were monoassociated with C. albicans for 4 weeks showed any histologic evidence of systemic candidiasis of endogenous origin. In contrast to systemic candidiasis, we observed no significant (P < 0.05) differences in susceptibility among IL-10 KO, IL-4 KO, and wild-type (immunocompetent) mice to orogastric candidiasis. Our results suggest that IL-10 exerts a negative effect on the early, innate response to acute systemic candidiasis; however, in comparison to immunocompetent control (wild-type) mice, neither IL-10 nor IL-4 deficiency enhanced susceptibility to orogastric candidiasis.

Cytokine production in cell culture by peripheral blood mononuclear cells from immunocompetent hosts

The production of interleukin 2 (IL-2) gamma interferon, IL-4, tumor necrosis factor alpha (TNF-alpha), TNF-beta, IL-5, and IL-10 in vitro by peripheral blood mononuclear cells cultured from healthy immunocompetent subjects after mitogen stimulation was determined. The mitogens used were concanavalin A, phytohemagglutinin, pokeweed mitogen, and Staphylococcus aureus Cowen. The results obtained provide a normal range for the production of these cytokines under specified conditions in vitro.