Parasite Immunology最新文献

C-type lectin receptors (CLRs) constitute a category of innate immune receptors that play an essential role in the antifungal immune response. For over two decades, scientists have uncovered what are the fungal ligands recognized by CLRs and how these receptors initiate the immune response. Such studies have allowed the identification of genetic polymorphisms in genes encoding for CLRs or for proteins involved in the signalisation cascade they trigger. Nevertheless, our understanding of how these receptors functions and the full extent of their function during the antifungal immune response is still at its infancy. In this review, we summarize some of the main findings about CLRs in antifungal immunity and discuss what the future might hold for the field.

Human fungal pathogens cause a broad plethora of infections, spanning cutaneous dermatophytoses to invasive infections in immunocompromised hosts. As eukaryotic pathogens are capable of morphotype switching, they present unique challenges both for drug development and the immunological response. Whilst current antifungal therapies are limited to the orally available triazoles, intravenous echonocandins and polyenes, and flucytosine and terbinafine, there has been recent significant progress in the antifungal armamentorium with ibrexafungerp, a novel orally available terpanoid that inhibits 1,3-beta-D-glucan-approved by Food and Drug Administration in 2021, and fosmanogepix, an orally available pro-drug of manogepix, which targets glycosylphosphatidylinositol-anchored protein maturation entering Phase 3 studies for candidaemia. A number of further candidates are in development. There has been significant use of existing immunotherapies such as recombinant interferon-γ and G-CSF for fungal disease in immunocompromised patients, and there are emerging opportunities for monoclonal antibodies targeting TH2 inflammation. Omalizumab, an anti-IgE monoclonal antibody in asthma, is now used routinely for the treatment of allergic bronchopulmonary aspergillosis, and further agents targeting IL-4 and IL-5 are being evaluated. In addition, T-cell CAR therapy is showing early promise for fungal disease. Thus, we are likely to see rapid advances to our approach to the management of fungal disease in the near future.

Retraction: Ajay Kumar, Sushmita Das, Abhishek Mandal, Sudha Verma, Kumar Abhishek, Ashish Kumar, Vinod Kumar, Ayan Kumar Ghosh, Pradeep Das (2018) Leishmania infection activates host mTOR for its survival by M2 macrophage polarization. Parasite Immunology 40(11): e12586; https://doi.org/10.1111/pim.12586 The above article, published online on 6 September 2018, in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editors-in-Chief, Eleanor M. Riley and Richard K. Grencis, and John Wiley and Sons Ltd. Following publication, concerns were raised by third parties regarding Figures 4b, 5b and 8b. The authors were unable to provide a satisfactory explanation and could not provide the original data. The retraction has been agreed because of concerns that the figures were duplicated, affecting the interpretation of the data and results presented.

Viral infection often induce the expression of murine fibrinogen-like protein 2 (mFGL2) triggering immune coagulation, which causes severe liver pathogenesis via increased fibrin deposition and thrombosis in the microvasculature. We aimed to investigate the role of mFGL2 in the liver stage of malaria infections. We reveal that infection with malaria sporozoites also induces increased expression of mFGL2 and that this expression is primarily located within the liver Kupffer and endothelial cells. In addition, we report that inhibition of FGL2 has no significant effect on immune coagulation but increases the expression of inflammatory cytokines in the livers of infected mice. Interestingly, FGL2 deficiency had no significant impact on the development of liver stage malaria parasites or the pathogenesis of the infected liver. In contrast to viral infections, we conclude that mFGL2 does not contribute to either parasite development or liver pathology during these infections, revealing the unique features of this protein in liver-stage malaria infections.

Retraction: RajKishor Pandey, Manas Ranjan Dikhit, Avinash Kumar, Budheswar Dehury, Krishna Pandey, Roshan Kamal Topno, Pradeep Das, Sanjiva Bimal (2020) Evaluating the immunomodulatory responses of LdODC-derived MHC Class-II restricted peptides against VL. Parasite Immunology 42(4): e12699; https://doi.org/10.1111/pim.12699   The above article, published online on 24 January 2020, in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editors-in-Chief, Eleanor M. Riley and Richard K. Grencis, and John Wiley and Sons Ltd. Following publication, concerns were raised by a third party regarding similarities in Figures 3 and 5. The authors were unable to provide a satisfactory explanation and could not provide the original data.   The retraction has been agreed because of concerns that the figures were duplicated, affecting the interpretation of the data and results presented.

Severe malaria occurs most in young children but is poorly understood due to the absence of a developmentally-equivalent rodent model to study the pathogenesis of the disease. Though functional and quantitative deficiencies in innate response and a biased T helper 1 (Th1) response are reported in newborn pups, there is little information available about this intermediate stage of the adaptive immune system in murine neonates. To fill this gap in knowledge, we have developed a mouse model of severe malaria in young mice using 15-day old mice (pups) infected with Plasmodium chabaudi. We observe similar parasite growth pattern in pups and adults, with a 60% mortality and a decrease in the growth rate of the surviving young mice. Using a battery of behavioral assays, we observed neurological symptoms in pups that do not occur in infected wildtype adults. CD4⁺ T cells were activated and differentiated to an effector T cell (Teff) phenotype in both adult and pups. However, there were relatively fewer and less terminally differentiated pup CD4⁺ Teff than adult Teff. Interestingly, despite less activation, the pup Teff expressed higher T-bet than adults' cells. These data suggest that Th1 cells are functional in pups during Plasmodium infection but develop slowly.

Haemonchus contortus is the most pathogenic parasite for sheep. The objective was to evaluate immunomodulation of the probiotic Saccharomyces boulardii in sheep experimentally infected with H. contortus. Twenty-four sheep were divided into three groups: one infected with 500 H. contortus larvae/day for 26 days and supplemented with S. boulardii (40 ml with 1 × 10⁸  CFU/ml/day); a control group only infected with H. contortus but not supplemented; and a naïve group that never came into contact with either parasites or S. boulardii. To assess the humoral immune response, production of specific serum IgG anti-somatic H. contortus antigen was evaluated through indirect ELISA. To assess the cellular immune response, cell populations and cytokine (IL-4, IL-5 and IL-10) production were evaluated through flow cytometry. For parasitological analyses, the counts of eggs per gram of faeces (EPG) and larvae per faecal culture were assessed. At all the study points, the concentration of IgG anti-H. contortus was higher (p < .05) in the S. boulardii group than in the other groups. The cell analysis revealed that there were significantly higher numbers (p < .05) of cells expressing MHC-II and significantly higher numbers (p < .05) of eosinophils in the mucosa in the S. boulardii group. Significant expression of IL-10 was observed only in the control infected group. There were significant reductions (p < .05) in EPG and larval counts in the S. boulardii supplemented group. These results show that S. boulardii supplementation modulated the immune response against H. contortus, thereby reducing its infection.

Haemonchus contortus (H. contortus) has caused a huge impact on the animal husbandry economy in the world's tropical and subtropical regions. Innate immunity is the first-line of host defence. The host recognizes pathogen-associated molecular patterns (PAMPs) through a variety of pattern recognition receptors (PRRs) and activates downstream signalling pathways to resist pathogens invasion. Therefore, elucidating the immune interaction between host and pathogen is key to understanding how the host resists the pathogen. We identified 1516 protein-protein interactions (PPIs) between goat innate immune signal pathway proteins and H. contortus excretory-secretory proteins (ESPs) by Recombination-based "Library vs. Library" yeast two-hybrid system (RLL-Y2H) and constructed the PPIs network. Among them, the NLR and IL-17 signalling pathways have the most protein interactions. And there were more interaction proteins between NOD1 and MUC5AC proteins in the pathways. Combined with the differentially expressed genes (DEGs) of susceptible and resistant goats identified in the preliminary work of our laboratory, we selected the intersection genes to construct the PPIs network, and TRAF2 appeared as a key protein of goat innate immune signalling pathway. We initially studied the PPIs between goat and H. contortus ESPs, which provides valuable information for better understanding the immune interaction between the goats and the H. contortus.

The golden hamster (Mesocricetus auratus) is commonly used as a promising model for Leishmania braziliensis infection developing skin-ulcerated lesions. However, different protocols using high concentration of parasites inoculated in the footpad result in severe clinical disease. Here, we further investigate the outcome of the site of infection and concentration of L. braziliensis parasites inoculated on the immunopathogenesis and clinical evolution. Initially, hamsters were infected in the ear dermis or hind footpad with a concentration of 1 × 10⁵ parasites. Animals infected in the ear dermis developed a disease, with an increased parasite load that more closely resembled human cutaneous leishmaniasis lesions comparing to the group infected in the footpad. Next, we evaluated if different parasite concentrations (10⁴ , 10⁵ and 10⁶ ) inoculated in the ear dermis would impact the course and clinical aspects of infection. Hamsters infected with 10⁴ and 10⁵ parasites developed mild lesions compared to the group infected with 10⁶ that presented severe and persistent lesions. The parasite load varied between the different parasite concentrations. The inflammatory response was more intense when infection was initiated with 10⁶ parasites accompanied by an increased initial expression of IL-4, IL-10 and arginase in the lymph node followed by expression of both pro-and anti-inflammatory cytokines comparing to groups infected with 10⁴ and 10⁵ parasites. In conclusion, the number of parasites inoculated, and the initial site of infection could influence the inflammatory response, and clinical presentation. Our results suggest that the ear dermis infection model induces a chronic disease that relates to immunopathological aspects of CL natural infection.