RESUMO
Trichophyton rubrum is causing an increasing number of invasive infections, especially in immunocompromised and diabetic patients. The fungal invasive infectious process is complex and has not yet been fully elucidated. Therefore, this study aimed to understand the cellular and molecular mechanisms during the interaction of macrophages and T. rubrum. For this purpose, we used a co-culture of previously germinated and heat-inactivated T. rubrum conidia placed in contact with human macrophages cell line THP-1 for 24 h. This interaction led to a higher level of release of interleukins IL-6, IL-2, nuclear factor kappa beta (NF-κB) and an increase in reactive oxygen species (ROS) production, demonstrating the cellular defense by macrophages against dead fungal elements. Cell viability assays showed that 70% of macrophages remained viable during co-culture. Human microRNA expression is involved in fungal infection and may modulate the immune response. Thus, the macrophage expression profile of microRNAs during co-culture revealed the modulation of 83 microRNAs, with repression of 33 microRNAs and induction of 50 microRNAs. These data were analyzed using bioinformatics analysis programs and the modulation of the expression of some microRNAs was validated by qRT-PCR. In silico analysis showed that the target genes of these microRNAs are related to the inflammatory response, oxidative stress, apoptosis, drug resistance, and cell proliferation.
RESUMO
Autosomal recessive (AR) CARD9 (caspase recruitment domain-containing protein 9) deficiency underlies invasive infections by fungi of the ascomycete phylum in previously healthy individuals at almost any age. Although CARD9 is expressed mostly by myeloid cells, the cellular basis of fungal infections in patients with inherited CARD9 deficiency is unclear. Therapy for fungal infections is challenging, with at least 20% premature mortality. We report two unrelated patients from Brazil and Morocco with AR CARD9 deficiency, both successfully treated with hematopoietic stem cell transplantation (HSCT). From childhood onward, the patients had invasive dermatophytic disease, which persisted or recurred despite multiple courses of antifungal treatment. Sanger sequencing identified homozygous missense CARD9 variants at the same residue, c.302G>T (p.R101L) in the Brazilian patient and c.301C>T (p.R101C) in the Moroccan patient. At the ages of 25 and 44 years, respectively, they received a HSCT. The first patient received a HLA-matched HSCT from his CARD9-mutated heterozygous sister. There was 100% donor chimerism at D + 100. The other patient received a T cell-depleted haploidentical HSCT from his CARD9-mutated heterozygous brother. A second HSCT from the same donor was performed due to severe amegakaryocytic thrombocytopenia despite achieving full donor chimerism (100%). At last follow-up, more than 3 years after HSCT, both patients have achieved complete clinical remission and stopped antifungal therapy. HSCT might be a life-saving therapeutic option in patients with AR CARD9 deficiency. This observation strongly suggests that the pathogenesis of fungal infections in these patients is largely due to the disruption of leukocyte-mediated CARD9 immunity.
Assuntos
Candidíase Mucocutânea Crônica/terapia , Transplante de Células-Tronco Hematopoéticas , Adulto , Antifúngicos/uso terapêutico , Candidíase Mucocutânea Crônica/diagnóstico por imagem , Candidíase Mucocutânea Crônica/imunologia , Pré-Escolar , Humanos , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Resultado do TratamentoRESUMO
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+Ly6Chigh 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.
Assuntos
Complicações do Diabetes , Tinha/imunologia , Receptor 2 Toll-Like/deficiência , Trichophyton/imunologia , Animais , Contagem de Colônia Microbiana , Citocinas/metabolismo , Modelos Animais de Doenças , Macrófagos/imunologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T Reguladores/imunologiaRESUMO
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.