Explore the vast range of titles available.

Neutrophils play a key role in defence against infection and in the activation and regulation of innate and adaptive immunity. In cancer, tumour-associated neutrophils (TANs) have emerged as an important component of the tumour microenvironment. Here, they can exert dual functions. TANs can be part of tumour-promoting inflammation by driving angiogenesis, extracellular matrix remodelling, metastasis and immunosuppression. Conversely, neutrophils can also mediate antitumour responses by direct killing of tumour cells and by participating in cellular networks that mediate antitumour resistance. Neutrophil diversity and plasticity underlie the dual potential of TANs in the tumour microenvironment. Myeloid checkpoints as well as the tumour and tissue contexture shape neutrophil function in response to conventional therapies and immunotherapy. We surmise that neutrophils can provide tools to tailor current immunotherapy strategies and pave the way to myeloid cell-centred therapeutic strategies, which would be complementary to current approaches.This Review discusses the emerging dual role played by neutrophils in the tumour microenvironment as part of tumour-promoting inflammation, while also mediating antitumour immune responses, and suggests that neutrophil function could be manipulated in myeloid cell-based therapeutic approaches to improve patient outcomes.

Interleukin-1 receptor 8 (IL-1R8), a negative regulator of the IL-1 family of cytokines, restrains the activity of natural killer (NK) cells, suggesting that IL-1R8 acts as a checkpoint regulator of NK cell activation and that its blockade may be of use in cancer therapy. IL-1R8 restrains natural killer cells Natural killer (NK) cells are innate lymphoid cells that contribute to host defence against viral infection and to the control of some types of cancer. Alberto Mantovani and colleagues show in this study that IL-1R8, a negative regulator of the IL-1 family of cytokines, restrains the activity of NK cells. IL-1R8-deficient mice have more mature NK cells with enhanced functional capabilities and are more resistant to NK-cell-dependent hepatic tumour models and murine cytomegalovirus infection. The results suggest that IL-1R8 acts as a checkpoint regulator of NK cell activation and that its blockade may be of use in cancer therapy. Interleukin-1 receptor 8 (IL-1R8, also known as single immunoglobulin IL-1R-related receptor, SIGIRR, or TIR8) is a member of the IL-1 receptor (ILR) family with distinct structural and functional characteristics, acting as a negative regulator of ILR and Toll-like receptor (TLR) downstream signalling pathways and inflammation 1 . Natural killer (NK) cells are innate lymphoid cells which mediate resistance against pathogens and contribute to the activation and orientation of adaptive immune responses 2 , 3 , 4 . NK cells mediate resistance against haematopoietic neoplasms but are generally considered to play a minor role in solid tumour carcinogenesis 5 , 6 , 7 . Here we report that IL-1R8 serves as a checkpoint for NK cell maturation and effector function. Its genetic blockade unleashes NK-cell-mediated resistance to hepatic carcinogenesis, haematogenous liver and lung metastasis, and cytomegalovirus infection.

Since the outset of the COVID-19 pandemic, increasing evidence suggests that the innate immune responses play an important role in the disease development. A dysregulated inflammatory state has been proposed as a key driver of clinical complications in COVID-19, with a potential detrimental role of granulocytes. However, a comprehensive phenotypic description of circulating granulocytes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–infected patients is lacking. In this study, we used high-dimensional flow cytometry for granulocyte immunophenotyping in peripheral blood collected from COVID-19 patients during acute and convalescent phases. Severe COVID-19 was associated with increased levels of both mature and immature neutrophils, and decreased counts of eosinophils and basophils. Distinct immunotypes were evident in COVID-19 patients, with altered expression of several receptors involved in activation, adhesion, and migration of granulocytes (e.g., CD62L, CD11a/b, CD69, CD63, CXCR4). Paired sampling revealed recovery and phenotypic restoration of the granulocytic signature in the convalescent phase. The identified granulocyte immunotypes correlated with distinct sets of soluble inflammatory markers, supporting pathophysiologic relevance. Furthermore, clinical features, including multiorgan dysfunction and respiratory function, could be predicted using combined laboratory measurements and immunophenotyping. This study provides a comprehensive granulocyte characterization in COVID-19 and reveals specific immunotypes with potential predictive value for key clinical features associated with COVID-19.

Complement has emerged as a component of tumor promoting inflammation. We conducted a systematic assessment of the role of complement activation and effector pathways in sarcomas. , and mice showed reduced susceptibility to 3-methylcholanthrene sarcomagenesis and transplanted sarcomas, whereas C1q and factor B deficiency had marginal effects. Complement 3a receptor (C3aR), but not C5aR1 and C5aR2, deficiency mirrored the phenotype of mice. C3 and C3aR deficiency were associated with reduced accumulation and functional skewing of tumor-associated macrophages, increased T cell activation and response to anti-PD-1 therapy. Transcriptional profiling of sarcoma infiltrating macrophages and monocytes revealed the enrichment of MHC II-dependent antigen presentation pathway in C3-deficient cells. In patients, C3aR expression correlated with a macrophage population signature and C3 deficiency-associated signatures predicted better clinical outcome. These results suggest that the lectin pathway and C3a/C3aR axis are key components of complement and macrophage-mediated sarcoma promotion and immunosuppression.

Chemokines play a fundamental role in lymphocyte development, mainly attributable to the control of the correct localization in the proper microenvironments of cells undergoing maturation. Natural killer (NK) cell development occurs in the bone marrow (BM) where their localization is regulated by the balance of chemokine function in cell retention into tissues and mobilization into circulation. In addition, NK cells from several extra-medullary tissues are phenotypically and functionally different from their circulating counterpart suggesting that maturation can be completed in organs other than BM. Indeed, a role of chemokines in NK cell localization into tissues during homeostatic conditions is also documented. In this review, we summarize the current notion related to the relevance of several chemokine/chemokine receptor axes in NK cell development with a focus on the regulation of their expression and function.

West Nile Virus (WNV) is becoming a significant and enduring public health menace in Europe, propelled by climate changes and accelerated population aging. Most infections are asymptomatic but older adults are more prone to develop neuroinvasive disease, which is characterized by high morbidity and mortality, as well as long-term neurological disturbances and disability. To date, there is still no licensed human vaccine or specific antiviral treatment, and management is mostly supportive. This review brings together the most recent information about WNV epidemiology, pathogenesis, and clinical manifestations, with a special focus on older people in Europe. We critically analyze current and novel pharmaceutical strategies, encompassing drug repurposing, nucleoside analogues, interferon-based therapies, peptides, monoclonal antibodies, and host-directed agents, emphasizing their therapeutic potential alongside the challenges presented by age-related pharmacokinetic and immunological alterations. We also discuss some important gaps in the current evidence base, such as the frequent exclusion of older adults from clinical studies and the lack of a coordinated clinical trial infrastructure that can be quickly activated during seasonal outbreaks. Lastly, we suggest a framework that combines systematic antiviral screening with the creation of a Europe-wide network of clinical trial readiness that is built into current One Health surveillance systems.

Prolonged SARS-CoV-2 infections are widely described in immunosuppressed patients, but safe and effective treatment strategies are lacking. We aimed to outline our approach to treating persistent COVID-19 in patients with immunosuppression from different causes. In this case series, we retrospectively enrolled all immunosuppressed patients with persistent SARS-CoV-2 infections treated at our centers between March 2022 and February 2023. Patients received different sequential or combination regimens, including antivirals (remdesivir, nirmatrelvir/ritonavir, or molnupiravir) and/or monoclonal antibodies (mAbs) (tixagevimab/cilgavimab or sotrovimab). The main outcome was a complete virological response (negative SARS-CoV-2 RT-PCR on nasopharyngeal swabs) at the end of treatment. Fifteen patients were included as follows: eleven (11/15; 73%) with hematological disease and four (4/15; 27%) with recently diagnosed HIV/AIDS infection. Six patients (6/15; 40%) received a single antiviral course, four patients (4/15; 27%) received an antiviral and mAbs sequentially, and two patients (13%) received three lines of treatment (a sequence of three antivirals or two antivirals and mAbs). A combination of two antivirals or one antiviral plus mAbs was administered in three cases (3/15, 20%). One patient died while still positive for SARS-CoV-2, while fourteen (14/15; 93%) tested negative within 16 days after the end of treatment. The median time to negativization since the last treatment was 2.5 days. Both sequential and combination regimens used in this study demonstrated high efficacy and safety in the high-risk group of immunosuppressed patients.

Among 128 adult people living with HIV and no neurological conditions confounding the cerebrospinal fluid results, the presence of HSV-1 chronic infection (detected either by serology or PCR), but not of HSV-2 and VZV, independently associated with higher odds of blood–brain barrier impairment, abnormally increased cerebrospinal fluid levels of tau and phosphorylated-181 tau, and decreased concentrations of fragments 1–42 of beta amyloid compared to the seronegative counterpart. These associations were even stronger for seropositive participants with a positive history of at least one symptomatic reactivation of HSV-1.