Identification and modulation of the allograft inflammatory factor-1 (AIF-1) homologous in the medicinal leech Hirudo Medicinalis.

Allograft inflammatory factor-1 (AIF-1) is a 17 kDa cytokine-inducible calcium-binding protein that in vertebrates plays an important role in allografts immune response and its expression is mostly limited to the monocyte/macrophage lineage. Recently it was assumed that AIF-1 was a novel molecule involved in inflammatory responses. To better clarify this aspect in the present study we investigated the expression of AIF-1 after bacterial challenge, wounds and tissue transplants and its potential role in regulating the innate immune response in an invertebrate model, the medicinal leech (Hirudo medicinalis). The analysis of an EST library from H. medicinalis CNS, revealed the presence of a gene, named Hmaif-1/alias Hmiba1, showing a high homology with vertebrate aif-1. Immunohistochemistry using an anti-HmAIF-1 polyclonal antibody showed that this protein is constitutively present in spread, CD68+ macrophage-like cells. A few hours after pathogen bacterial injection in the body wall, the amount of these immunopositive cells increases at the injected site, co-expressing HmAIF-1 and the common leukocyte marker CD45. A similar overview was observed in the early stages of wound healing, especially at 24 hours after injury, with a lot of immunopositive cells around the lesion site. Moreover here we demonstrated that the recombinant protein HmAIF-1 induced a massive angiogenesis and it was also a potent chemoattractant for macrophages. After rHmAIF-1 stimulation, macrophage-like cells co-expressed the macrophage marker CD68 and the surface glycoprotein CD45, which in Vertebrates is implicated in the integrinmediated adhesion of macrophages and plays a key role in regulating the functional responsiveness of cells to chemoattractants. We therefore hypothesized that CD45 could play a role for leech macrophage-like cells activation and migration towards the inflammation site and we examined its potential effect on HmAIF-1-induced signaling

Serum amyloid P component is an essential element of resistance against Aspergillus fumigatus

© The Author(s) 2021. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Serum amyloid P component (SAP, also known as Pentraxin 2; APCS gene) is a component of the humoral arm of innate immunity involved in resistance to bacterial infection and regulation of tissue remodeling. Here we investigate the role of SAP in antifungal resistance. Apcs-/- mice show enhanced susceptibility to A. fumigatus infection. Murine and human SAP bound conidia, activate the complement cascade and enhance phagocytosis by neutrophils. Apcs-/- mice are defective in vivo in terms of recruitment of neutrophils and phagocytosis in the lungs. Opsonic activity of SAP is dependent on the classical pathway of complement activation. In immunosuppressed mice, SAP administration protects hosts against A. fumigatus infection and death. In the context of a study of hematopoietic stem-cell transplantation, genetic variation in the human APCS gene is associated with susceptibility to invasive pulmonary aspergillosis. Thus, SAP is a fluid phase pattern recognition molecule essential for resistance against A. fumigatus.The contribution of the European Commission (ERC project PHII-669415; FP7 project 281608 TIMER; ESA/ITN, H2020-MSCA-ITN-2015-676129), Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) (project FIRB RBAP11H2R9), Associazione Italiana Ricerca sul Cancro (AIRC IG-19014 and IG-21714, AIRC 5 × 1000 −9962 and −21147), the Italian Ministry of Health, the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) (NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000023), the Fundação para a Ciência e Tecnologia (FCT) (UIDB/50026/2020, UIDP/50026/2020, PTDC/SAU-SER/29635/2017, PTDC/MED-GEN/28778/2017, CEECIND/04058/2018 and CEECIND/03628/2017), the European Union’s Horizon 2020 research and innovation program under grant agreement no. 847507 and the “la Caixa” Foundation (ID 100010434) and FCT under the agreement LCF/PR/HR17/52190003 is gratefully acknowledged.info:eu-repo/semantics/publishedVersio

Nanobodies as Versatile Tool for Multiscale Imaging Modalities

Molecular imaging is constantly growing in different areas of preclinical biomedical research. Several imaging methods have been developed and are continuously updated for both in vivo and in vitro applications, in order to increase the information about the structure, localization and function of molecules involved in physiology and disease. Along with these progresses, there is a continuous need for improving labeling strategies. In the last decades, the single domain antigen-binding fragments nanobodies (Nbs) emerged as important molecular imaging probes. Indeed, their small size (~15 kDa), high stability, affinity and modularity represent desirable features for imaging applications, providing higher tissue penetration, rapid targeting, increased spatial resolution and fast clearance. Accordingly, several Nb-based probes have been generated and applied to a variety of imaging modalities, ranging from in vivo and in vitro preclinical imaging to super-resolution microscopy. In this review, we will provide an overview of the state-of-the-art regarding the use of Nbs in several imaging modalities, underlining their extreme versatility and their enormous potential in targeting molecules and cells of interest in both preclinical and clinical studies

Identification of CX3CR1 + mononuclear phagocyte subsets involved in HIV-1 and SIV colorectal transmission

International audienc

Single-Cell Sequencing of Mouse Heart Immune Infiltrate in Pressure Overload-Driven Heart Failure Reveals Extent of Immune Activation

BACKGROUND: Inflammation is a key component of cardiac disease, with macrophages and T lymphocytes mediating essential roles in the progression to heart failure. Nonetheless, little insight exists on other immune subsets involved in the cardiotoxic response.METHODS: Here, we used single-cell RNA sequencing to map the cardiac immune composition in the standard murine nonischemic, pressure-overload heart failure model. By focusing our analysis on CD45(+) cells, we obtained a higher resolution identification of the immune cell subsets in the heart, at early and late stages of disease and in controls. We then integrated our findings using multiparameter flow cytometry, immunohistochemistry, and tissue clarification immunofluorescence in mouse and human.RESULTS: We found that most major immune cell subpopulations, including macrophages, B cells, T cells and regulatory T cells, dendritic cells, Natural Killer cells, neutrophils, and mast cells are present in both healthy and diseased hearts. Most cell subsets are found within the myocardium, whereas mast cells are found also in the epicardium. Upon induction of pressure overload, immune activation occurs across the entire range of immune cell types. Activation led to upregulation of key subset-specific molecules, such as oncostatin M in proinflammatory macrophages and PD-1 in regulatory T cells, that may help explain clinical findings such as the refractivity of patients with heart failure to anti-tumor necrosis factor therapy and cardiac toxicity during anti-PD-1 cancer immunotherapy, respectively.CONCLUSIONS: Despite the absence of infectious agents or an autoimmune trigger, induction of disease leads to immune activation that involves far more cell types than previously thought, including neutrophils, B cells, Natural Killer cells, and mast cells. This opens up the field of cardioimmunology to further investigation by using toolkits that have already been developed to study the aforementioned immune subsets. The subset-specific molecules that mediate their activation may thus become useful targets for the diagnostics or therapy of heart failure