Maria Danielma dos Santos Reis

Leishmania infections profoundly reshape host immunity, yet their impact on central T‐cell development remains underappreciated. The thymus, a key site for establishing a functional and self‐tolerant T‐cell repertoire, is highly sensitive to systemic inflammatory cues. Growing evidence indicates that parasitic diseases, including leishmaniasis, can perturb thymic structure and function through direct parasite presence or sustained inflammatory stress. Such disturbances may alter thymocyte maturation, leading to reduced T‐cell output and the release of cells with aberrant specificity. Beyond compromising protective immunity, these changes may create conditions favourable to immune dysregulation, including the emergence of autoimmune manifestations and a microenvironment permissive to malignant transformation. This narrative review synthesises current findings on how Leishmania interacts with immunological tissues and highlights the thymus as a potential and overlooked target whose dysfunction may bridge infection, autoimmunity and cancer.

The age-related thymic involution has intrigued scientists since its first observations. This phenomenon is well-conserved across different species, but the reason why it exists is not clear since the thymus is a key organ in the immune system responsible for the maturation of immunocompetent T lymphocytes. As thymic function declines with age, it significantly affects the health of older individuals, leading to reduced responses to new pathogens, tumor cells, and vaccines. This impact was notably evident during the COVID-19 pandemic, where a substantial number of elderly individuals succumbed to the disease. This chapter explores the characteristics of age-related thymic involution, including new findings using recently developed technologies. We also highlight emerging research trends aimed at rejuvenating thymus function.

Liraglutide plays a crucial role in managing weight and regulating glucose levels, but it can have adverse effects, particularly on the gastrointestinal tract. Here, we assessed the impact of liraglutide on the viability, cell death, morphology, reorganization of the actin cytoskeleton, and migration of rat intestinal epithelial cells. There was no change in the viability of cells treated with liraglutide at concentrations of 0.25, 0.5, and 1 μM, however, high concentrations of the drug reduced IEC- 6 cell viability. Additionally, the treatment with low doses of liraglutide decreased the rate of apoptosis of IEC-6 cells relative to the control. Also, the treated cells showed a modified actin cytoskeleton, with prominent stress fibers. Regarding cell migration, there was a decrease in the percentage of closure of the cell-free area over 24 h, relative to the untreated cells. This study revealed the direct effects of liraglutide on intestinal cells, including reduced apoptosis rates, actin cytoskeleton alterations, and inhibited cell migration.

Thymic epithelial cells (TECs) dysfunction can lead to disorders in the adaptive immune response, resulting in immunodeficiency or autoimmune diseases. Therefore, the investigation of new drugs with immunomodulatory capacity can contribute to the development of strategies to improve thymic functions. In this context, this study aimed to investigate the in vitro effects of the pentacyclic triterpene friedelin (FD) on TEC biology. For this, murine 2BH4 cells were treated with 0.1 and 1 μM FD for 24 h. After treatment, fibronectin and laminin production was increased (16% and 37% respectively) by TECs, however it did not alter the expression of CXCL12 chemokine. The interaction between TEC and thymocytes was also evaluated, in which a greater adhesion (45%) and survival (228%) of thymocytes to treated-TECs was observed. MHC molecules were up-regulated by FD treatment plus thymocyte coculture. Based on these results it was possible to attest that FD has an important and promissory role in the physiology of murine TECs.

ObjectivePolyphenols are organic compounds with diverse biological activities such as anti-inflammatory and antioxidant effects, making them important candidates for the development of anti-aging drugs. In this systematic review, we aimed to answer the question: can plant-derived polyphenols have an immunomodulatory effect in experimental models of aging?MethodsWe systematically searched Web of Science, MEDLINE/Pubmed, and Embase to select articles using the following combinations of terms and synonyms: polyphenols, phenols, senescence, aging, and immune. The selected articles were evaluated for reporting quality and risk-of-bias according to standard guidelines.ResultsThe most used polyphenol was resveratrol, followed by curcumin, salidroside, and gallic acid. These molecules demonstrated an ability to restore immune function both in vitro and in vivo. The mechanism of action was not completely elucidated in these studies, but inhibition of NF-kB signaling, and antioxidant properties seemed to account for the anti-aging effects. All articles included in the review had good quality of reporting but failed to describe an adequate sample size, criteria for inclusion/exclusion, randomization, and blinding.ConclusionWe conclude that polyphenols are promising immunomodulatory substances for use in anti-aging therapies. However, more research with standardized analysis is needed to understand the role of these molecules in the prevention or reduction of damage associated with the aging process, as well as to determine the safety profile and consequences of systemic action.

Bowdichia virgilioides Kunth (Fabaceae) is a medicinal plant from South America popularly known as “sucupira-preta”. Parts of this plant are used in traditional medicine to treat various diseases, especially inflammation and diabetes. Phytochemical analysis of extracts obtained from B. virgilioides showed a wide variety of bioactive compounds, such as anthocyanins, alkaloids, terpenoids, essential oils, condensed tannins, saponins and steroids. In vivo and in vitro studies have corroborated the popular use of this plant, in addition to elucidating the action of some of its isolated compounds.

Stryphnodendron adstringens (Mart.) Coville is a medicinal plant found in South America whose stem bark is used to treat disorders of the female genitourinary system, gastric ulcers, wounds, and other diseases. Extracts of this plant mainly contain tannins, phenolic acids, and triterpenoids. Important preclinical studies have shown that S. adstringens has anti-inflammatory effects in animal models of acute and chronic inflammation, as well as antimicrobial activity against microorganisms of clinical importance. In addition to these effects, this plant showed toxicity in animal models, this should be considered when recommending the popular use of this plant.

Background: Age-related impairments in macrophage functions have important consequences for the health of the elderly population. The aging process is also accompanied by a reduction in several hormones, including growth hormone (GH). Previous studies have shown that this hormone can affect macrophage activity in young individuals; however, the biological effects of GH stimulation on macrophages during aging have not yet been elucidated. Objective: The aim of this work was to investigate the in vitro effects of GH on peritoneal macrophages from aged mice. Methods: Peritoneal macrophages isolated from young (4 months-old) and old (12-15 months-old) mice were treated in vitro with 100 ng/mL of GH for 24 hours. After treatment, cells were analysed for cell morphology, reactive oxygen species (ROS) production, expression of integrins, cell adhesion to extracellular matrix molecules, and migration in transwell chambers. Results: Although GH-treated cells from old mice exhibited decreased ROS production, we did not observe the effects of GH on macrophage morphology or macrophage phagocytic activity in young and old mice-derived cell cultures. Macrophages from old mice had increased adhesion to laminin and fibronectin substrates, as did cells obtained from young mice treated with GH, but no change was observed in the expression of integrin receptors. Furthermore, cells from old mice exhibited increased migration compared to young mice and a significant increase in macrophage migration was observed under GH stimulation. Conclusion: Our results showed that GH can interfere with the motility of macrophages from old mice, advancing our understanding of the interactions between the immune and neuroendocrine systems during aging.

The thymus is responsible for thymocyte differentiation into immunocompetent T lymphocytes. Different cell types in the thymic microenvironment actively cooperate in this process, interacting with ...