Parasite Immunology最新文献

Helminths are large multicellular parasites responsible for widespread chronic disease in humans and animals. Intestinal helminths live in close proximity with the host gut microbiota and mucosal immune network, resulting in reciprocal interactions that closely influence the course of infections. Diet composition may strongly regulate gut microbiota composition and intestinal immune function and therefore may play a key role in modulating anti-helminth immune responses. Characterizing the multitude of interactions that exist between different dietary components (e.g., dietary fibres), immune cells, and the microbiota, may shed new light on regulation of helminth-specific immunity. This review focuses on the current knowledge of how metabolism of dietary components shapes immune response during helminth infection, and how this information may be potentially harnessed to design new therapeutics to manage parasitic infections and associated diseases.

Bullous pemphigoid (BP) with scabies is a condition rarely encountered in clinical practice, and when it is encountered, it is often due to the use of immunosuppressants. This paper is a report on a patient with BP and scabies, who developed scabs after taking dexamethasone. It should be noted that BP antibody is necessary, which can distinguish BP with scabies and bullous scabies, and the treatment options for the two diseases are different.

Visceral leishmaniasis (VL) is a neglected disease with a broad spectrum of clinical manifestations and involvement of visceral organs. Organ-specific immune response against the Leishmania donovani (Ld) complex is not yet understood due to the unavailability of an appropriate experimental model. In reference to our recent work on comparing the hamster model with VL patients, it is now possible to understand immune profiling in different visceral organs. This may offer an answer to varying parasite loads in different visceral organs in the same host. Herein, we analysed a panel of immune markers (Th-2/Th-1) in visceral organs of Ld-infected hamsters and quantified parasitic load in the same tissues using qPCR assay. In spleen, liver, bone marrow and lymph node (mesenteric) from Ld-infected hamsters, the parasite burden was quantified along with mRNA expression of a panel of Th-2 and Th-1 type immune markers, namely IL-10, IL-4, Arginase-I, GATA-3, SOCS-3, IL-12, IFN-γ, iNOS, T-bet and SOCS-5. A clear dichotomy was absent between Th-2 and Th-1 type immune markers and the major players of this immune response were IFN-γ, IL-10, T-bet, GATA-3, SOCS-5 and SOCS-3.

The parasitic ciliate Cryptocaryon irritans, which infects almost all marine fish species occurring in both tropical and subtropical regions throughout the world. The disease, cryptocaryonosis, accounts for significant economic losses to the aquaculture industry. This review attempts to provide a comprehensive overview of the biology of the parasite, host-parasite interactions and both specific and non-specific host defense mechanisms are responsible for the protection of fish against challenge infections with this ciliate. Also, this article reflects the current interest in this subject area and the quest to develop an available vaccine against the disease. Due to the high frequency of clinical fish cryptocaryonosis, the study of fish immune responses to C. irritans provides an optimal experimental model for understanding immunity against extracellular protozoa.

In Central America, infection by Leishmania (Leishmania) infantum chagasi causes visceral leishmaniasis and non-ulcerated cutaneous leishmaniasis (NUCL). This work aimed to evaluate the participation of subpopulations of antigen-presenting cells in skin lesions of patients affected by NUCL through double-staining immunohistochemistry using cellular and intracellular markers. Twenty-three skin biopsies from patients affected by NUCL were used. Histological sections stained by HE were used for histopathological study. Immunohistochemical studies were performed using primary antibodies against Langerhans cells, dermal dendritic cells, T lymphocytes, and the cytokines IL-12, IFN-γ, TNF-α, iNOS, and IL-10. The histopathological lesions were characterized by an inflammatory infiltrate, predominantly lymphohistiocytic, of variable intensity, with a diffuse arrangement associated with epithelioid granulomas and discreet parasitism. Double-staining immunohistochemistry showed higher participation of dendritic cells producing the proinflammatory cytokine IL-12 in relation to the other evaluated cytokines. Activation of the cellular immune response was marked by a higher density of CD8 Tc1-lymphocytes followed by CD4 Th1-lymphocytes producing mainly IFN-γ. The data obtained in the present study suggest that antigen-presenting cells play an important role in the in situ immune response through the production of proinflammatory cytokines, directing the cellular immune response preferentially to the Th1 and Tc1 types in NUCL caused by L. (L.) infantum chagasi.

The aim of this work was to define the population of regulatory T cells (Tregs) which are circulating in the blood of Leishmania infected individuals clinically displaying a lesion (active disease-AD) and sub-clinical (SC) ones. We have individually collected blood samples, processed the PBMC and stained with fluorochrome-conjugated antibodies against CD3, CD4, Foxp3, CD25, CTLA-4, Ki-67, CCR4, CCR5, and CCR7. Cells were analyzed by flow cytometry. Our results suggest that CD25 and CTLA-4 are upregulated in Tregs of AD patients when compared to SC and uninfected (UN) controls. Moreover, Tregs proliferate upon infection based on Ki-67 nuclear antigen staining. Finally, we have observed that these Tregs of SC and AD patients upregulate CCR4, but not CCR5 and CCR7. There is an increase in the number of circulating Tregs in the blood of Leishmania infected individuals. These cells are potentially more suppressive based on the increased upregulation of CD25 and CTLA-4 during clinical infection (AD) when compared to SC infection. Tregs of both SC and AD cohorts are proliferating and express CCR4, which potentially guide them to the skin, but do not upregulate CCR5 and CCR7.

The emergence of deadly fungal infections in Africa is primarily driven by a disproportionately high burden of human immunodeficiency virus (HIV) infections, lack of access to quality health care, and the unavailability of effective antifungal drugs. Immunocompromised people in Africa are therefore at high risk of infection from opportunistic fungal pathogens such as Cryptococcus neoformans and Pneumocystis jirovecii, which are associated with high morbidity, mortality, and related socioeconomic impacts. Other emerging fungal threats include Emergomyces spp., Histoplasma spp., Blastomyces spp., and healthcare-associated multi-drug resistant Candida auris. Socioeconomic development and the Covid-19 pandemic may influence shifts in epidemiology of invasive fungal diseases on the continent. This review discusses the epidemiology, clinical manifestations, and current management strategies available for these emerging fungal diseases in Africa. We also discuss gaps in knowledge, policy, and research to inform future efforts at managing these fungal threats.

Fungi represent an integral part of the skin microbiota. Their complex interaction network with the host shapes protective immunity during homeostasis. If host defences are breached, skin-resident fungi including Malassezia and Candida, and environmental fungi such as dermatophytes can cause cutaneous infections. In addition, fungi are associated with diverse non-infectious skin disorders. Despite their multiple roles in health and disease, fungi remain elusive and understudied, and the mechanisms underlying the emergence of pathological conditions linked to fungi are largely unclear. The identification of IL-17 as an important antifungal effector mechanism represents a milestone for understanding homeostatic antifungal immunity. At the same time, host-adverse, disease-promoting roles of IL-17 have been delineated, as in psoriasis. Fungal dysbiosis represents another feature of many pathological skin conditions with an unknown causal link of intra- and interkingdom interactions to disease pathogenesis. The emergence of new fungal pathogens such as Candida auris highlights the need for more research into fungal immunology to understand how antifungal responses shape health and diseases. Recent technological advances for genetically manipulating fungi to target immunomodulatory fungal determinants, multi-omics approaches for studying immune cells in the human skin, and novel experimental models open up a promising future for skin fungal immunity.