Evolution of innate immunity: lessons from mammalian models shaping our current view of insect immunity.

The innate immune system, a cornerstone for organismal resilience against environmental and microbial insults, is highly conserved across the evolutionary spectrum, underpinning its pivotal role in maintaining homeostasis and ensuring survival. This review explores the evolutionary parallels between mammalian and insect innate immune systems, illuminating how investigations into these disparate immune landscapes have been reciprocally enlightening. We further delve into how advancements in mammalian immunology have enriched our understanding of insect immune responses, highlighting the intertwined evolutionary narratives and the shared molecular lexicon of immunity across these organisms. Therefore, this review posits a holistic understanding of innate immune mechanisms, including immunometabolism, autophagy and cell death. The examination of how emerging insights into mammalian and vertebrate immunity inform our understanding of insect immune responses and their implications for vector-borne disease transmission showcases the imperative for a nuanced comprehension of innate immunity's evolutionary tale. This understanding is quintessential for harnessing innate immune mechanisms' potential in devising innovative disease mitigation strategies and promoting organismal health across the animal kingdom.

The dichotomic role of single cytokines: Fine-tuning immune responses.

Cytokines are known for their pleiotropic effects. They can be classified by their function as pro-inflammatory, such as tumor necrosis factor (TNF), interleukin (IL) 1 and IL-12, or anti-inflammatory, like IL-10, IL-35 and transforming growth factor ß (TGF-ß). Though this type of classification is an important simplification for the understanding of the general cytokine's role, it can be misleading. Here, we discuss recent studies that show a dichotomic role of the so-called pro and anti-inflammatory cytokines, highlighting that their function can be dependent on the microenvironment and their concentrations. Furthermore, we discuss how the back-and-forth interplay between cytokines and immunometabolism can influence the dichotomic role of inflammatory responses as an important target to complement cytokine-based therapies.

Inhibition of O-GlcNAcylation Reduces Cell Viability and Autophagy and Increases Sensitivity to Chemotherapeutic Temozolomide in Glioblastoma.

Glioblastoma (GB) is the most aggressive primary malignant brain tumor and is associated with short survival. O-GlcNAcylation is an intracellular glycosylation that regulates protein function, enzymatic activity, protein stability, and subcellular localization. Aberrant O-GlcNAcylation is related to the tumorigenesis of different tumors, and mounting evidence supports O-GlcNAc transferase (OGT) as a potential therapeutic target. Here, we used two human GB cell lines alongside primary human astrocytes as a non-tumoral control to investigate the role of O-GlcNAcylation in cell proliferation, cell cycle, autophagy, and cell death. We observed that hyper O-GlcNAcylation promoted increased cellular proliferation, independent of alterations in the cell cycle, through the activation of autophagy. On the other hand, hypo O-GlcNAcylation inhibited autophagy, promoted cell death by apoptosis, and reduced cell proliferation. In addition, the decrease in O-GlcNAcylation sensitized GB cells to the chemotherapeutic temozolomide (TMZ) without affecting human astrocytes. Combined, these results indicated a role for O-GlcNAcylation in governing cell proliferation, autophagy, cell death, and TMZ response, thereby indicating possible therapeutic implications for treating GB. These findings pave the way for further research and the development of novel treatment approaches which may contribute to improved outcomes and increased survival rates for patients facing this challenging disease.

Two national mammography quality certification programs in Brazil: Framework and main outcomes between 2017 and 2021.

BACKGROUND: This study aims to provide an academic medical overview of the framework and key outcomes of two mammography quality certification programs in Brazil. METHODS: These programs assess radiation dose and phantom image quality in mammography units through a postal system. Each unit that passes this initial assessment is required to submit a sample of copies of five complete examinations. The quality of the patient images and reports is then reviewed by radiologists and medical physicist experts. Additionally, the number of mammography units and mammography coverage in the target population, were assessed. RESULTS: During the study period, 1007 units applied to the certification programs, and 934 (92.8%) successfully passed the assessment of radiation dose and phantom image quality. Out of these, 556 (59.5%) also passed the review of clinical image quality and reports, earning certification. The main issues related to mammogram and report quality were associated with the performance of radiographers (in terms of positioning) and radiologists (in terms of interpretation). On average, there are more than two mammography units/10,000 women in the target group. The screening mammography coverage in this group is 26.3% for women relying exclusively on the public healthcare and 58.1% for women with private healthcare plans. CONCLUSION: This study demonstrates the suitability of the framework adopted by national mammography quality certification programs in a middle-income country. These programs are carried out by relatively small workforce and at reasonable costs, utilizing postal resources to cover the large number of existing mammographic units and the vast distances within the country. POLICY STATEMENT: All mammography services in Brazil must adhere to the quality requirements for examinations and reference values for radiation dose to women established by the Ministry of Health. This ensures standardized conditions for early detection of breast cancer and minimizes the risk associated with x-rays.

Distinct T helper cell-mediated antitumor immunity: T helper 2 cells in focus.

The adaptive arm of the immune system is crucial for appropriate antitumor immune responses. It is generally accepted that clusters of differentiation 4+ (CD4+) T cells, which mediate T helper (Th) 1 immunity (type 1 immunity), are the primary Th cell subtype associated with tumor elimination. In this review, we discuss evidence showing that antitumor immunity and better prognosis can be associated with distinct Th cell subtypes in experimental mouse models and humans, with a focus on Th2 cells. The aim of this review is to provide an overview and understanding of the mechanisms associated with different tumor outcomes in the face of immune responses by focusing on the (1) site of tumor development, (2) tumor properties (i. e., tumor metabolism and cytokine receptor expression), and (3) type of immune response that the tumor initially escaped. Therefore, we discuss how low-tolerance organs, such as lungs and brains, might benefit from a less tissue-destructive immune response mediated by Th2 cells. In addition, Th2 cells antitumor effects can be independent of CD8+ T cells, which would circumvent some of the immune escape mechanisms that tumor cells possess, like low expression of major histocompatibility-I (MHC-I). Finally, this review aims to stimulate further studies on the role of Th2 cells in antitumor immunity and briefly discusses emerging treatment options.

COVID-19 diverse outcomes: Aggravated reinfection, type I interferons and antibodies.

SARS-CoV-2 infection intrigued medicine with diverse outcomes ranging from asymptomatic to severe acute respiratory syndrome (SARS) and death. After more than two years of pandemic, reports of reinfection concern researchers and physicists. Here, we will discuss potential mechanisms that can explain reinfections, including the aggravated ones. The major topics of this hypothesis paper are the disbalance between interferon and antibodies responses, HLA heterogeneity among the affected population, and increased proportion of cytotoxic CD4+ T cells polarization in relation to T follicular cells (Tfh) subtypes. These features affect antibody levels and hamper the humoral immunity necessary to prevent or minimize the viral burden in the case of reinfections.

The different facets of heme-oxygenase 1 in innate and adaptive immunity.

Heme oxygenase (HO) enzymes are responsible for the main oxidative step in heme degradation, generating equimolar amounts of free iron, biliverdin and carbon monoxide. HO-1 is induced as a crucial stress response protein, playing protective roles in physiologic and pathological conditions, due to its antioxidant, anti-apoptotic and anti-inflammatory effects. The mechanisms behind HO-1-mediated protection are being explored by different studies, affecting cell fate through multiple ways, such as reduction in intracellular levels of heme and ROS, transcriptional regulation, and through its byproducts generation. In this review we focus on the interplay between HO-1 and immune-related signaling pathways, which culminate in the activation of transcription factors important in immune responses and inflammation. We also discuss the dual interaction of HO-1 and inflammatory mediators that govern resolution and tissue damage. We highlight the dichotomy of HO-1 in innate and adaptive immune cells development and activation in different disease contexts. Finally, we address different known anti-inflammatory pharmaceuticals that are now being described to modulate HO-1, and the possible contribution of HO-1 in their anti-inflammatory effects.

From a recombinant key antigen to an accurate, affordable serological test: Lessons learnt from COVID-19 for future pandemics.

Serological tests detect antibodies generated by infection or vaccination, and are indispensable tools along different phases of a pandemic, from early monitoring of pathogen spread up to seroepidemiological studies supporting immunization policies. This work discusses the development of an accurate and affordable COVID-19 antibody test, from production of a recombinant protein antigen up to test validation and economic analysis. We first developed a cost-effective, scalable technology to produce SARS-COV-2 spike protein and then used this antigen to develop an enzyme-linked immunosorbent assay (ELISA). A receiver operator characteristic (ROC) analysis allowed optimizing the cut-off and confirmed the high accuracy of the test: 98.6% specificity and 95% sensitivity for 11+ days after symptoms onset. We further showed that dried blood spots collected by finger pricking on simple test strips could replace conventional plasma/serum samples. A cost estimate was performed and revealed a final retail price in the range of one US dollar, reflecting the low cost of the ELISA test platform and the elimination of the need for venous blood sampling and refrigerated sample handling in clinical laboratories. The presented workflow can be completed in 4 months from first antigen expression to final test validation. It can be applied to other pathogens and in future pandemics, facilitating reliable and affordable seroepidemiological surveillance also in remote areas and in low-income countries.

Autophagy Modulators in Coronavirus Diseases: A Double Strike in Viral Burden and Inflammation.

Coronaviruses are the etiologic agents of several diseases. Coronaviruses of critical medical importance are characterized by highly inflammatory pathophysiology, involving severe pulmonary impairment and infection of multiple cell types within the body. Here, we discuss the interplay between coronaviruses and autophagy regarding virus life cycle, cell resistance, and inflammation, highlighting distinct mechanisms by which autophagy restrains inflammatory responses, especially those involved in coronavirus pathogenesis. We also address different autophagy modulators available and the rationale for drug repurposing as an attractive adjunctive therapy. We focused on pharmaceuticals being tested in clinical trials with distinct mechanisms but with autophagy as a common target. These autophagy modulators act in cell resistance to virus infection and immunomodulation, providing a double-strike to prevent or treat severe disease development and death from coronaviruses diseases.

The Unfolded Protein Response and Autophagy on the Crossroads of Coronaviruses Infections.

The ability to sense and adequately respond to variable environmental conditions is central for cellular and organismal homeostasis. Eukaryotic cells are equipped with highly conserved stress-response mechanisms that support cellular function when homeostasis is compromised, promoting survival. Two such mechanisms - the unfolded protein response (UPR) and autophagy - are involved in the cellular response to perturbations in the endoplasmic reticulum, in calcium homeostasis, in cellular energy or redox status. Each of them operates through conserved signaling pathways to promote cellular adaptations that include re-programming transcription of genes and translation of new proteins and degradation of cellular components. In addition to their specific functions, it is becoming increasingly clear that these pathways intersect in many ways in different contexts of cellular stress. Viral infections are a major cause of cellular stress as many cellular functions are coopted to support viral replication. Both UPR and autophagy are induced upon infection with many different viruses with varying outcomes - in some instances controlling infection while in others supporting viral replication and infection. The role of UPR and autophagy in response to coronavirus infection has been a matter of debate in the last decade. It has been suggested that CoV exploit components of autophagy machinery and UPR to generate double-membrane vesicles where it establishes its replicative niche and to control the balance between cell death and survival during infection. Even though the molecular mechanisms are not fully elucidated, it is clear that UPR and autophagy are intimately associated during CoV infections. The current SARS-CoV-2 pandemic has brought renewed interest to this topic as several drugs known to modulate autophagy - including chloroquine, niclosamide, valinomycin, and spermine - were proposed as therapeutic options. Their efficacy is still debatable, highlighting the need to better understand the molecular interactions between CoV, UPR and autophagy.

Intracerebral Injection of Heme Induces Lipid Peroxidation, Neuroinflammation, and Sensorimotor Deficits.

Background and Purpose: Heme is a red blood cell component released in the brain parenchyma following intracerebral hemorrhage. However, the study of the pathophysiological mechanisms triggered by heme in the brain is hampered by the lack of well-established in vivo models of intracerebral heme injection. This study aims to optimize and characterize a protocol of intrastriatal heme injection in mice, with a focus on the induction of lipid peroxidation, neuroinflammation and, ultimately, sensorimotor deficits. We also evaluated the involvement of NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3), an inflammasome sensor, in the behavior deficits induced by heme in this model. Methods: Mice were injected with heme in the striatum for the evaluation of neuroinflammation and brain damage through histological and biochemical techniques. Immunoblot was used to evaluate the expression of proteins involved in heme/iron metabolism and antioxidant responses and the activation of the MAPK (mitogen-activated protein kinase) signaling pathway. For the assessment of neurological function, we followed-up heme-injected mice for 2 weeks using the rotarod, elevated body swing, and cylinder tests. Mice injected with the vehicle (sham), or autologous blood were used as controls. Results: Heme induced lipid peroxidation and inflammation in the brain. Moreover, heme increased the expression of HO-1 (heme oxygenase-1), ferritin, p62, and superoxide dismutase 2, and activated the MAPK signaling pathway promoting pro-IL (interleukin)-1ß production and its cleavage to the active form. Heme-injected mice exhibited signs of brain damage and reactive astrogliosis around the injection site. Behavior deficits were observed after heme or autologous blood injection in comparison to sham-operated controls. In addition, behavior deficits and IL-1ß production were reduced in Nlrp3 knockout mice in comparison to wild-type mice. Conclusions: Our results show that intracerebral heme injection induces neuroinflammation, and neurological deficits, in an NLRP3-dependent manner, suggesting that this is a feasible model to evaluate the role of heme in neurological disorders.

Heme oxygenase-1 in protozoan infections: A tale of resistance and disease tolerance.

Heme oxygenase (HO-1) mediates the enzymatic cleavage of heme, a molecule with proinflammatory and prooxidant properties. HO-1 activity deeply impacts host capacity to tolerate infection through reduction of tissue damage or affecting resistance, the ability of the host to control pathogen loads. In this Review, we will discuss the contribution of HO-1 in different and complex protozoan infections, such as malaria, leishmaniasis, Chagas disease, and toxoplasmosis. The complexity of these infections and the pleiotropic effects of HO-1 constitute an interesting area of study and an opportunity for drug development.

The induction of host cell autophagy triggers defense mechanisms against Trypanosoma cruzi infection in vitro.

Trypanosoma cruzi causes Chagas disease, a neglected illness that affects millions of people worldwide, especially in Latin America. The balance between biochemical pathways triggered by the parasite and host cells response will ultimately define the progression of a life-threatening disease, justifying the efforts to understand cellular mechanisms for infection restrain. In this interaction, parasite and host cells are affected by different physiological responses as autophagy modulation, which could be under intense cellular stress, such as nutrient deprivation, hormone depletion, or infection. Autophagy is a constitutive pathway that leads to degradation of macromolecules and cellular structures and may induce cell death. In Trypanosoma cruzi infection, the relevance of host autophagy is controversial regarding in vitro parasite intracellular life cycle. In the present study, we evaluated host cell autophagy during T. cruzi infection in phagocytic and non-professional phagocytic cells. We described that the presence of the parasite increased the number of LC3 puncta, a marker for autophagy, in cardiac cells and peritoneal macrophages in vitro. The induction of host autophagy decreased infection in macrophages in early and late time-periods. We suggest that starved phagocytic cells reduced internalization, also confirmed by inert particles and dead trypomastigotes. Whereas, in cardiac cells, starvation-induced autophagy decreased lipid droplets and infection in later time-point, by reducing parasite differentiation/proliferation. In ATG5 knockout MEF cells, we confirmed our hypothesis of autophagy machinery activation during parasite internalization, increasing infection. Our data suggest that host autophagy downregulates T. cruzi infection through impairing parasite intracellular life cycle, reducing the infection in primary culture cells.

The anti-inflammatory and anti-oxidative actions of eugenol improve lipopolysaccharide-induced lung injury.

Acute lung injury (ALI) remains a major cause of mortality. In lipopolysaccharide (LPS)-stimulated macrophages, eugenol reduces cyclooxygenase-2 expression, NF-κB activation, and inflammatory mediators. We examined the anti-inflammatory and anti-oxidative action of eugenol in an in vivo model of LPS-induced lung injury. Lung mechanics and histology were analyzed in mice 24 h after LPS exposure, with and without eugenol treatment at different doses. Additional animals, submited to the same protocol, were treated with eugenol at 150 mg/kg to determine its effect on inflammatory cytokines (ELISA) and oxidative markers. LPS-induced lung functional and histological changes were significantly improved by eugenol, in a dose-dependent way. Furthermore, eugenol (150 mg/kg) was able to inhibit the release of inflammatory cytokines (TNF-α, IL-1ß and IL-6), NADPH oxidase activity, as well as antioxidant enzymes activity (superoxide dismutase, catalase and glutathione peroxidase). Finally, eugenol reduced LPS-induced protein oxidation. In conclusion, eugenol improved in vivo LPS-induced ALI through both anti-inflammatory and anti-oxidative effects, avoiding damage to lung structure.

Autophagy and Its Interaction With Intracellular Bacterial Pathogens.

Cellular responses to stress can be defined by the overwhelming number of changes that cells go through upon contact with and stressful conditions such as infection and modifications in nutritional status. One of the main cellular responses to stress is autophagy. Much progress has been made in the understanding of the mechanisms involved in the induction of autophagy during infection by intracellular bacteria. This review aims to discuss recent findings on the role of autophagy as a cellular response to intracellular bacterial pathogens such as, Streptococcus pyogenes, Mycobacterium tuberculosis, Shigella flexneri, Salmonella typhimurium, Listeria monocytogenes, and Legionella pneumophila, how the autophagic machinery senses these bacteria directly or indirectly (through the detection of bacteria-induced nutritional stress), and how some of these bacterial pathogens manage to escape from autophagy.

O Controle de Qualidade em Mamografia e o INCA: Aspectos Históricos e Resultados / Quality Control in Mammography and INCA: Historical Aspects and Results / El Control de Calidad en Mamografía y el INCA: Aspectos Históricos y Resultados

Introdução: Programas de rastreamento mamográfico exigem o controle da qualidade dos exames e uso seguro da radiação. No Brasil, o Instituto Nacional de Câncer José Alencar Gomes da Silva (INCA) acompanhou esse processo. Objetivo: Descrever o contexto histórico do controle das doses e da qualidade da mamografia no Brasil sob a perspectiva do INCA e os resultados obtidos por dois programas de qualidade de abrangência nacional. Método: Pesquisa descritiva, de abordagem mista, utilizando documentos e publicações relacionadas ao controle de qualidade em mamografia e resultados dos programas do INCA e do Colégio Brasileiro de Radiologia e Diagnóstico por Imagem (CBR) entre 2009 e 2016. Resultados: A pesquisa documental descreve as ações de controle de qualidade da mamografia desde a década de 1970 até o ano de 2012. Entre 2009 e 2016, foram realizadas 1.156 medidas de dose em 738 serviços e 2.633 avaliações da qualidade dos exames em 390 serviços. O valor médio da dose glandular média foi de 1,81 mGy por incidência, com 22,7% das avaliações acima dos valores de referência. Em relação à qualidade dos exames, 14,0% não estavam conformes quanto aos critérios clínicos de qualidade da imagem, 5,8% quanto aos critérios físicos e 16,7% quanto à classificação BI-RADS®. Conclusão: A análise documental revela marcos importantes da qualidade da mamografia nas últimas décadas. Os resultados dos programas do INCA e do CBR fornecem informações relevantes para o desenvolvimento de ações dirigidas ao controle da dose e da qualidade da imagem e dos laudos em mamografia.

Abstract Introduction: Mammographic screening programs require quality control of the exams and safe use of radiation. In Brazil, the National Cancer Institute José Alencar Gomes da Silva (INCA) followed this process. Objective: To describe the historical context of dose control and mammography quality in Brazil from the INCA perspective and the results obtained by two national quality programs. Method: Descriptive research with mixed approach, using documents and publications related to mammography quality control and results of the programs of INCA and the Brazilian College of Radiology and Diagnostic Imaging (CBR) between 2009 and 2016. Results: The documentary research describes the actions of quality mammography control from the 1970s to the year 2012. Between 2009 and 2016, 1,156 dose measurements were performed in 738 services and 2,633 evaluations of exams quality in 390 services. The mean value of the mean glandular dose was 1.81 mGy per incidence, with 22.7% of the assessments above the reference values. Regarding the quality of the exams, 14.0% were not according to the clinical criteria of image quality, 5.8% regarding the physical criteria and 16.7% regarding the BI-RADS® classification. Conclusion: Documentary analysis reveals important milestones in the quality of mammography in recent decades. The results of INCA and CBR programs provide relevant information for the development of actions directed to dose and image quality control and mammography reports.

Resumen Introducción: Programas de cribado en mamografía exigen un riguroso control de calidad y uso seguro de la radiación. En Brasil, el Instituto Nacional de Cáncer José Alencar Gomes da Silva (INCA) acompaña este proceso. Objetivo: Describir el contexto histórico del control de las dosis y la calidad de la mamografía en Brasil desde la perspectiva del INCA, así como resultados alcanzados por programas de alcance nacional. Método: Investigación descriptiva, de abordaje cualitativa y cuantitativa, utilizando documentos y publicaciones del INCA y del Colegio Brasileño de Radiología y Diagnóstico por Imagen (CBR) para servicios verificados entre 2009 y 2016. Resultados: La búsqueda documental mostró las acciones del control de calidad en mamografía desde la década de 1970 hasta el año 2012. Entre 2012 y 2016 se realizaron 1.156 verificaciones de dosis en 738 servicios y 2.633 evaluaciones de calidad del examen en 390 servicios. El valor promedio de la dosis glandular media fue de 1,81 mGy por proyección y el 22,7% de ellas fuera de los valores de referencia. 14,0% no estaban conformes en relación a los criterios clínicos de calidad de la imagen, 5,8% en relación a los criterios físicos y 16,7% en relación a la clasificación BI-RADS® informada. Conclusión: El análisis documental muestra marcos importantes sobre la calidad de la mamografía en las últimas décadas. Los resultados de los programas del INCA y el CBR, ofrecen informaciones relevantes para desarrollar acciones dirigidas a la calidad de la imagen, el control de las dosis y los informes médicos.

Heme and iron induce protein aggregation.

Heme is an essential molecule expressed in many tissues where it plays key roles as the prosthetic group of several proteins involved in vital physiological and metabolic processes such as gas and electron transport. Structurally, heme is a tetrapyrrole ring containing an atom of iron (Fe) in its center. When released into the extracellular milieu, heme exerts several deleterious effects, which make it an important player in infectious and noninfectious hemolytic diseases where large amounts of free heme are observed such as malaria, dengue fever, ß-thalassemia, sickle cell disease and ischemia-reperfusion. Our recent work has uncovered an unappreciated cellular response triggered by heme or Fe, one of its degradation products, on macrophages, which is the formation of protein aggregates known as aggresome-like induced structres (ALIS). This response was shown to be fully dependent on ROS production and the activation of the transcription factor NFE2L2/NRF2. In addition, we have demonstrated that heme degradation by HMOX1/HO-1 (heme oxygenase 1) is required and that Fe is essential for the formation of ALIS, as heme analogs lacking the central atom of Fe are not able to induce these structures. ALIS formation is also observed in vivo, in a model of phenylhydrazine (PHZ)-induced hemolysis, indicating that it is an integral part of the host response to excessive free heme and that it may play a role in cellular homeostasis.

Protein aggregation as a cellular response to oxidative stress induced by heme and iron.

Hemolytic diseases include a variety of conditions with diverse etiologies in which red blood cells are destroyed and large amounts of hemeproteins are released. Heme has been described as a potent proinflammatory molecule that is able to induce multiple innate immune responses, such as those triggered by TLR4 and the NLRP3 inflammasome, as well as necroptosis in macrophages. The mechanisms by which eukaryotic cells respond to the toxic effects induced by heme to maintain homeostasis are not fully understood, however. Here we describe a previously uncharacterized cellular response induced by heme: the formation of p62/SQTM1 aggregates containing ubiquitinated proteins in structures known as aggresome-like induced structures (ALIS). This action is part of a response driven by the transcription factor NRF2 to the excessive generation of reactive oxygen species induced by heme that results in the expression of genes involved in antioxidant responses, including p62/SQTM1. Furthermore, we show that heme degradation by HO-1 is required for ALIS formation, and that the free iron released on heme degradation is necessary and sufficient to induce ALIS. Moreover, ferritin, a key protein in iron metabolism, prevents excessive ALIS formation. Finally, in vivo, hemolysis promotes an increase in ALIS formation in target tissues. Our data unravel a poorly understood aspect of the cellular responses induced by heme that can be explored to better understand the effects of free heme and free iron during hemolytic diseases such as sickle cell disease, dengue fever, malaria, and sepsis.