An HLA-E-targeted TCR bispecific molecule redirects T cell immunity against Mycobacterium tuberculosis.

Peptides presented by HLA-E, a molecule with very limited polymorphism, represent attractive targets for T cell receptor (TCR)-based immunotherapies to circumvent the limitations imposed by the high polymorphism of classical HLA genes in the human population. Here, we describe a TCR-based bispecific molecule that potently and selectively binds HLA-E in complex with a peptide encoded by the inhA gene of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis in humans. We reveal the biophysical and structural bases underpinning the potency and specificity of this molecule and demonstrate its ability to redirect polyclonal T cells to target HLA-E-expressing cells transduced with mycobacterial inhA as well as primary cells infected with virulent Mtb. Additionally, we demonstrate elimination of Mtb-infected cells and reduction of intracellular Mtb growth. Our study suggests an approach to enhance host T cell immunity against Mtb and provides proof of principle for an innovative TCR-based therapeutic strategy overcoming HLA polymorphism and therefore applicable to a broader patient population.

Netosis and trained immunity in tick-borne diseases: a possible pathogenetic role.

Various types of pathogens transmitted by ticks elicit distinct immune responses just like the emerging α-Gal syndrome that is associated with allergic reactions to tick bites. The mechanisms of Neutrophil Extracellular Traps release (called NETosis) and trained immunity in response to tick-borne microbes have not been extensively investigated. In our paper, we explored the intricate interplay of NETosis and trained immunity within the realm of infectious diseases triggered by tick bites and their possible pathogenetic role in autoimmunity. We conducted an extensive literature search to identify studies for this review, considering articles and reviews published in English within the last years. Additionally, we scrutinized the references of all included papers and relevant review articles to ensure comprehensive coverage. We shed light on a plausible correlation between these innate immune responses and their potential implication in certain pathological conditions, with a specific focus on some autoimmune diseases. These findings offer new perspectives for a more profound comprehension of the immunopathogenesis of certain autoimmune-like signs where clinicians should include Tick-Borne Diseases (TBDs) in their differential diagnoses, in those geographical areas of tick infestation.

Emerging Roles of Cells and Molecules of Innate Immunity in Alzheimer's Disease.

The inflammatory response that marks Alzheimer's disease (neuroinflammation) is considered a double-edged sword. Microglia have been shown to play a protective role at the beginning of the disease. Still, persistent harmful stimuli further activate microglia, inducing an exacerbating inflammatory process which impairs ß-amyloid peptide clearance capability and leads to neurotoxicity and neurodegeneration. Moreover, microglia also appear to be closely involved in the spread of tau pathology. Soluble TREM2 also represents a crucial player in the neuroinflammatory processes. Elevated levels of TREM2 in cerebrospinal fluid have been associated with increased amyloid plaque burden, neurodegeneration, and cognitive decline in individuals with Alzheimer's disease. Understanding the intricate relationship between innate immunity and Alzheimer's disease will be a promising strategy for future advancements in diagnosis and new therapeutic interventions targeting innate immunity, by modulating its activity. Still, additional and more robust studies are needed to translate these findings into effective treatments. In this review, we focus on the role of cells (microglia, astrocytes, and oligodendrocytes) and molecules (TREM2, tau, and ß-amyloid) of the innate immune system in the pathogenesis of Alzheimer's disease and their possible exploitation as disease biomarkers and targets of therapeutical approaches.

Deep Immunoprofiling of Large-Scale Tuberculosis Dataset at Single Cell Resolution Reveals a CD81bright γδ T Cell Population Associated with Latency.

Tuberculosis (TB) remains one of the leading causes of death among infectious diseases, with 10.6 million new cases and 1.3 million deaths reported in 2022, according to the most recent WHO report. Early studies have shown an expansion of γδ T cells following TB infection in both experimental models and humans, indicating their abundance among lung lymphocytes and suggesting a role in protective immune responses against Mycobacterium tuberculosis (M. tuberculosis) infection. In this study, we hypothesized that distinct subsets of γδ T cells are associated with either protection against or disease progression in TB. To explore this, we applied large-scale scRNA-seq and bulk RNA-seq data integration to define the phenotypic and molecular characteristics of peripheral blood γδ T cells. Our analysis identified five unique γδ T subclusters, each with distinct functional profiles. Notably, we identified a unique cluster significantly enriched in the TCR signaling pathway, with high CD81 expression as a conserved marker. This distinct molecular signature suggests a specialized role for this cluster in immune signaling and regulation of immune response against M. tuberculosis. Flow cytometry confirmed our in silico results, showing that the mean fluorescence intensity (MFI) values of CD81 expression on γδ T cells were significantly increased in individuals with latent TB infection (TBI) compared to those with active TB (ATB). This finding underscores the importance of CD81 and its associated signaling mechanisms in modulating the activity and function of γδ T cells under TBI conditions, providing insights into potential therapeutic targets for TB management.

Integrated Analysis of Single-Cell and Bulk RNA Sequencing Data Reveals Memory-like NK Cell Subset Associated with Mycobacterium tuberculosis Latency.

Natural killer (NK) cells are innate-like lymphocytes that belong to the family of type-1 innate lymphoid cells and rapidly respond to virus-infected and tumor cells. In this study, we have combined scRNA-seq data and bulk RNA-seq data to define the phenotypic and molecular characteristics of peripheral blood NK cells. While the role of NK cells in immune surveillance against virus infections and tumors has been well established, their contribution to protective responses to other intracellular microorganisms, such as Mycobacterium tuberculosis (Mtb), is still poorly understood. In this study, we have combined scRNA-seq data and bulk RNA-seq data to illuminate the molecular characteristics of circulating NK cells in patients with active tuberculosis (TB) disease and subjects with latent Mtb infection (LTBI) and compared these characteristics with those of healthy donors (HDs) and patients with non-TB other pulmonary infectious diseases (ODs). We show here that the NK cell cluster was significantly increased in LTBI subjects, as compared to patients with active TB or other non-TB pulmonary diseases and HD, and this was mostly attributable to the expansion of an NK cell population expressing KLRC2, CD52, CCL5 and HLA-DRB1, which most likely corresponds to memory-like NK2.1 cells. These data were validated by flow cytometry analysis in a small cohort of samples, showing that LTBI subjects have a significant expansion of NK cells characterized by the prevalence of memory-like CD52+ NKG2C+ NK cells. Altogether, our results provide some new information on the role of NK cells in protective immune responses to Mtb.

Cow's Milk: A Benefit for Human Health? Omics Tools and Precision Nutrition for Lactose Intolerance Management.

Cow's milk (CM) is a healthy food consumed worldwide by individuals of all ages. Unfortunately, "lactase-deficient" individuals cannot digest milk's main carbohydrate, lactose, depriving themselves of highly beneficial milk proteins like casein, lactoalbumin, and lactoglobulin due to lactose intolerance (LI), while other individuals develop allergies specifically against these proteins (CMPA). The management of these conditions differs, and an inappropriate diagnosis or treatment may have significant implications for the patients, especially if they are infants or very young children, resulting in unnecessary dietary restrictions or avoidable adverse reactions. Omics technologies play a pivotal role in elucidating the intricate interactions between nutrients and the human body, spanning from genetic factors to the microbiota profile and metabolites. This comprehensive approach enables the precise delineation and identification of distinct cohorts of individuals with specific dietary requirements, so that tailored nutrition strategies can be developed. This is what is called personalized nutrition or precision nutrition (PN), the area of nutrition that focuses on the effects of nutrients on the genome, proteome, and metabolome, promoting well-being and health, preventing diseases, reducing chronic disease incidence, and increasing life expectancy. Here, we report the opinion of the scientific community proposing to replace the "one size fits all" approach with tailor-made nutrition programs, designed by integrating nutrigenomic data together with clinical parameters and microbiota profiles, taking into account the individual lactose tolerance threshold and needs in terms of specific nutrients intake. This customized approach could help LI patients to improve their quality of life, overcoming depression or anxiety often resulting from the individual perception of this condition as different from a normal state.

Correction: Shekarkar Azgomi et al. A Rapid and Simple Multiparameter Assay to Quantify Spike-Specific CD4 and CD8 T Cells after SARS-CoV-2 Vaccination: A Preliminary Report. Biomedicines 2021, 9, 1576.

In the original publication, there was a mistake in Figure 1A, as published [...].

Phenotypic and Immunometabolic Aspects on Stem Cell Memory and Resident Memory CD8+ T Cells.

The immune system, smartly and surprisingly, saves the exposure of a particular pathogen in its memory and reacts to the pathogen very rapidly, preventing serious diseases. Immunologists have long been fascinated by understanding the ability to recall and respond faster and more vigorously to a pathogen, known as "memory". T-cell populations can be better described by using more sophisticated techniques to define phenotype, transcriptional and epigenetic signatures and metabolic pathways (single-cell resolution), which uncovered the heterogeneity of the memory T-compartment. Phenotype, effector functions, maintenance, and metabolic pathways help identify these different subsets. Here, we examine recent developments in the characterization of the heterogeneity of the memory T cell compartment. In particular, we focus on the emerging role of CD8+ TRM and TSCM cells, providing evidence on how their immunometabolism or modulation can play a vital role in their generation and maintenance in chronic conditions such as infections or autoimmune diseases.

Immunity and Nutrition: The Right Balance in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is an increasingly urgent medical problem that strongly impairs quality of life for patients. A global rise in incidence has been observed over the last few decades, with the highest incidence rates recorded in North America and Europe. Still, an increased incidence has been reported in the last ten years in newly industrialized countries in Asia, including China and India, both with more than one billion inhabitants. These data underline that IBD is an urgent global health problem. In addition, it is estimated that between 20% and 30% of IBD patients will develop colorectal cancer (CRC) within their lifetime and CRC mortality is approximately 50% amongst IBD patients. Although the exact etiology of IBD is still being defined, it is thought to be due to a complex interaction between many factors, including defects in the innate and adaptive immune system; microbial dysbiosis, i.e., abnormal levels of, or abnormal response to, the gastrointestinal microbiome; a genetic predisposition; and several environmental factors. At present, however, it is not fully understood which of these factors are the initiators of inflammation and which are compounders. The purpose of this review is to analyze the complex balance that exists between these elements to maintain intestinal homeostasis and prevent IBD or limit adverse effects on people's health.

Metabolic Reprogramming of Innate Immune Cells as a Possible Source of New Therapeutic Approaches in Autoimmunity.

Immune cells undergo different metabolic pathways or immunometabolisms to interact with various antigens. Immunometabolism links immunological and metabolic processes and is critical for innate and adaptive immunity. Although metabolic reprogramming is necessary for cell differentiation and proliferation, it may mediate the imbalance of immune homeostasis, leading to the pathogenesis and development of some diseases, such as autoimmune diseases. Here, we discuss the effects of metabolic changes in autoimmune diseases, exerted by the leading actors of innate immunity, and their role in autoimmunity pathogenesis, suggesting many immunotherapeutic approaches.

Role of hematopoietic cells in Mycobacterium tuberculosis infection.

Tuberculosis remains one of the most significant causes of mortality worldwide and the current situation shows a re-emergence of TB due to the emergence of new antibiotic-resistant strains and the widespread of disease caused by immunodeficiencies. For these reasons, a big effort is made to improve the therapeutic strategies against Mycobacterium tuberculosis and to perform new therapeutic and diagnostic strategies. This review analyzes the various hematopoietic populations, their role and the different changes they undergo during Mycobacterium tuberculosis infection or disease. We have examined the population of lymphocytes, monocytes, neutrophils, eosinophils and platelets, in orderto understand how each of them is modulated during the course of infection/disease. In this way it will be possible to highlight the correlations between these cell populations and the different stages of tubercular infection. In fact, Mycobacterium tuberculosis is able to influence both proliferation and differentiation of hematopoietic stem cells. Several studies have highlighted that Mycobacterium tuberculosis can also infect progenitor cells in the bone marrow during active disease driving towards an increase of myeloid differentiation. This review focuses how the different stages of tubercular infection could impact on the different hematopoietic populations, with the aim to correlate the changes of different populations as biomarkers useful to discriminate infection from disease and to evaluate the effectiveness of new therapies.

A Rapid and Simple Multiparameter Assay to Quantify Spike-Specific CD4 and CD8 T Cells after SARS-CoV-2 Vaccination: A Preliminary Report.

mRNA and Adenovirus vaccines for COVID-19 are used to induce humoral and cell-mediated immunity, with the aim to generate both SARS-CoV-2 B and T memory cells. In present study, we described a simple assay to detect and quantify Spike-specific CD4+ and CD8+ T cell responses induced by vaccination in healthy donors and in subjects with B cell compart impairment, in which antibody response is absent due to primary immunodeficiencies or CD20 depleting therapy. We detect and quantified memory T cell immune responses against SARS-CoV-2 evocated by vaccination in both groups, irrespective to the humoral response. Furthermore, we identified TNF-α as the main cytokine produced by T memory cells, after antigen-specific stimulation in vitro, that could be considered, other than IFN-γ, an additional biomarker of induction of T memory cells upon vaccination. Further studies on the vaccine-induced T cell responses could be crucial, not only in healthy people but also in immunocompromised subjects, where antigen specific T cells responses play a protective role against SARS-CoV-2.

LIODetect®TB-ST: Evaluation of novel blood test for a rapid diagnosis of active pulmonary and extra-pulmonary tuberculosis in IGRA confirmed patients.

Because of the current limits of immunological tests in the diagnosis of tuberculosis there is a need to identify new and rapid tests that can be carried out on a large scale in endemic countries and useful in the identification of infected subjects, but also able to discriminate those with latent infection from subjects with active. We have taken into consideration and analysed the LIODetect®TB-ST Tuberculosis Rapid Test, a membrane test for the qualitative detection of specific IgG, IgA, and IgM antibodies against Mycobacterium tuberculosis, performed on serum, plasma, or whole blood.85 samples positive to QuantiFERON TB-GOLD PLUS test were processed using this test and the results obtained were concordant with clinical diagnosis.To our knowledge, the LIODetect®TB-ST Tuberculosis Rapid Test is the only test; that identifies active tuberculosis disease with high sensitivity and specificity and its use might be of help in the diagnosis of tuberculosis, especially in endemic countries.

Recent Advances on the Innate Immune Response to Coxiella burnetii.

Coxiella burnetii is an obligate intracellular Gram-negative bacterium and the causative agent of a worldwide zoonosis known as Q fever. The pathogen invades monocytes and macrophages, replicating within acidic phagolysosomes and evading host defenses through different immune evasion strategies that are mainly associated with the structure of its lipopolysaccharide. The main transmission routes are aerosols and ingestion of fomites from infected animals. The innate immune system provides the first host defense against the microorganism, and it is crucial to direct the infection towards a self-limiting respiratory disease or the chronic form. This review reports the advances in understanding the mechanisms of innate immunity acting during C. burnetii infection and the strategies that pathogen put in place to infect the host cells and to modify the expression of specific host cell genes in order to subvert cellular processes. The mechanisms through which different cell types with different genetic backgrounds are differently susceptible to C. burnetii intracellular growth are discussed. The subsets of cytokines induced following C. burnetii infection as well as the pathogen influence on an inflammasome-mediated response are also described. Finally, we discuss the use of animal experimental systems for studying the innate immune response against C. burnetii and discovering novel methods for prevention and treatment of disease in humans and livestock.