RESUMO
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host's immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis.
Assuntos
Infestações por Ácaros , Ácaros , Rosácea , Animais , Cães , Amigos , Humanos , Infestações por Ácaros/tratamento farmacológico , Infestações por Ácaros/veterinária , Rosácea/tratamento farmacológico , Rosácea/veterinária , PeleRESUMO
Demodex mites have been suggested to have a role in various cutaneous and ocular disorders pathogenesis, such as rosacea or blepharitis. Evaluation of potential treatments with anti-Demodex effects is difficult because the viability of living mites needs to be evaluated during their exposure to the agent being tested. Mite viability is currently based solely on their observed movement. However, this method of assessing viability has significant limitations as mites may be resting, immobile or paralysed at any given observation point giving the observer a false impression of the organism's death. To overcome this limitation we evaluated a new quantitative method of evaluating the viability of Demodex mites by using scattered light intensity (SLI). We demonstrated that when combined with observation of mite motility, SLI provided increased accuracy of the evaluation of viability of mites being studied. This new viability assay will help address the technical challenges of mite viability experiments. Accurate evaluation of mite viability will enhance mite biology research and allow for more accurate in vitro toxicity assays of proposed anti-mite agents.
Assuntos
Entomologia/métodos , Ácaros/fisiologia , Animais , Luz , MovimentoAssuntos
Ácaros , Animais , Biópsia , Técnicas In Vitro , Infestações por Ácaros/parasitologia , Pele/parasitologiaRESUMO
Th2 immunity and allergic immune surveillance play critical roles in host responses to pathogens, parasites and allergens. Numerous studies have reported significant links between Th2 responses and cancer, including insights into the functions of IgE antibodies and associated effector cells in both antitumour immune surveillance and therapy. The interdisciplinary field of AllergoOncology was given Task Force status by the European Academy of Allergy and Clinical Immunology in 2014. Affiliated expert groups focus on the interface between allergic responses and cancer, applied to immune surveillance, immunomodulation and the functions of IgE-mediated immune responses against cancer, to derive novel insights into more effective treatments. Coincident with rapid expansion in clinical application of cancer immunotherapies, here we review the current state-of-the-art and future translational opportunities, as well as challenges in this relatively new field. Recent developments include improved understanding of Th2 antibodies, intratumoral innate allergy effector cells and mediators, IgE-mediated tumour antigen cross-presentation by dendritic cells, as well as immunotherapeutic strategies such as vaccines and recombinant antibodies, and finally, the management of allergy in daily clinical oncology. Shedding light on the crosstalk between allergic response and cancer is paving the way for new avenues of treatment.
Assuntos
Hipersensibilidade/imunologia , Imunoterapia/métodos , Neoplasias/imunologia , Anticorpos , Humanos , Imunoglobulina E/imunologia , Vigilância Imunológica , Imunoterapia/tendências , Neoplasias/terapia , Células Th2/imunologiaRESUMO
Intestinal helminth parasites are potent inducers of T helper type 2 (Th2) response and have a regulatory role, notably on intestinal inflammation. As infection with schistosomes is unlikely to provide a reliable treatment of inflammatory bowel diseases, we have investigated the beneficial effect of a schistosome enzymatic protein, the 28-kDa glutathione S-transferase (P28GST), on the modulation of disease activity and immune responses in experimental colitis. Our results showed that immunization with recombinant P28GST is at least as efficient as established schistosome infection to reduce colitis lesions and expression of pro-inflammatory cytokines. Considering underlying mechanisms, the decrease of inflammatory parameters was associated with the polarization of the immune system toward a Th2 profile, with local and systemic increases of interleukin (IL)-13 and IL-5. Dense eosinophil infiltration was observed in the colons of P28GST-immunized rats and mice. Depletion of eosinophils by treatment with an anti-Siglec-F monoclonal antibody and use of IL-5-deficient mice led to the loss of therapeutic effect, suggesting the crucial role for eosinophils in colitis prevention by P28GST. These findings reveal that immunization with P28GST, a unique recombinant schistosome enzyme, ameliorates intestinal inflammation through eosinophil-dependent modulation of harmful type 1 responses, representing a new immuno-regulatory strategy against inflammatory bowel diseases.