Alloxan (ALX) and streptozotocin (STZ) are extensively used to induce type 1 diabetes (T1D) in animal models. This study is aimed at evaluating the differences in immune parameters caused by ALX and STZ. T1D was induced either with ALX or with STZ, and the animals were followed for up to 180 days. Both ALX and STZ induced a decrease in the total number of circulating leukocytes and lymphocytes, with an increase in granulocytes when compared to control mice (CT). STZ‐treated mice also exhibited an increase in neutrophils and a reduction in the lymphocyte percentage in the bone marrow. In addition, while the STZ‐treated group showed a decrease in total CD3⁺, CD4^-CD8⁺, and CD4⁺CD8⁺ T lymphocytes in the thymus and CD19⁺ B lymphocytes in the pancreas and spleen, the ALX group showed an increase in CD4^-CD8⁺ and CD19⁺ only in the thymus. Basal levels of splenic interleukin‐ (IL‐) 1β and pancreatic IL‐6 in the STZ group were decreased. Both diabetic groups showed atrophy of the thymic medulla and degeneration of pancreatic islets of Langerhans composed of inflammatory infiltration and hyperemia with vasodilation. ALX‐treated mice showed a decrease in reticuloendothelial cells, enhanced lymphocyte/thymocyte cell death, and increased number of Hassall’s corpuscles. Reduced in vitro activation of splenic lymphocytes was found in the STZ‐treated group. Furthermore, mice immunized with ovalbumin (OVA) showed a more intense antigen‐specific paw edema response in the STZ‐treated group, while production of anti‐OVA IgG1 antibodies was similar in both groups. Thereby, important changes in immune cell parameters in vivo and in vitro were found at an early stage of T1D in the STZ‐treated group, whereas alterations in the ALX‐treated group were mostly found in the chronic phase of T1D, including increased mortality rates. These findings suggest that the effects of ALX and STZ influenced, at different times, lymphoid organs and their cell populations.

Immunosenescence, a process with a dysfunctional immune response that may favor infection is associated with an increase in inflammatory responses mediated by proinflammatory cytokines, characteristic of inflammaging. Aging and immunosenescence have a relationship relating to oxidative stress and inflammaging. Therefore, natural antioxidant compounds could be candidates for the control of the oxidative process. Our purpose was to evaluate the effect of resveratrol (Resv) on the antioxidant, antiviral, and anti-inflammatory responses induced by toll-like receptors (TLRs) 3, 4, and 7/8 agonists stimulation on peripheral blood mononuclear cells (PBMCs) of elderly and healthy female individuals (63–82 years old) and young and healthy female individuals (21–31 years old). Our data show that Resv may upregulate antioxidant factor expression, such as catalase (CAT) and SIRT1, in response to TLR4 and TLR7/8 agonists, similarly in both young and aged groups. Moreover, the Resv anti-inflammatory effect was detected by inhibiting IL-1β, TNF-α, and IL-10 secretion levels, as well as by the chemokines CCL2 and CCL5, induced by TLR4 and TLR7/8 stimulation. Curiously, Resv decreased antiviral genes, such as MxA, STING, and IRF7 expression, possibly by reducing the inflammatory effects of interferon-induced genes. Taken together, our results demonstrate the ability of Resv to stimulate antioxidant factors, leading to a downmodulation of the inflammatory response induced by innate immune stimulation. These findings point out Resv as a strategy to control the upregulation of inflammatory response, even in elderly individuals.

Sézary syndrome (SS) is a rare and aggressive type of cutaneous T-cell lymphoma, with an abnormal inflammatory response in affected skin. The cytokines IL-1B and IL-18, as key signaling molecules in the immune system, are produced in an inactive form and cleave to the active form by inflammasomes. In this study, we assessed the skin, serum, peripheral mononuclear blood cell (PBMC) and lymph-node samples of SS patients and control groups (healthy donors (HDs) and idiopathic erythroderma (IE) nodes) to investigate the inflammatory markers IL-1B and IL-18 at the protein and transcript expression levels, as potential markers of inflammasome activation. Our findings showed increased IL-1B and decreased IL-18 protein expression in the epidermis of SS patients; however, in the dermis layer, we detected increased IL-18 protein expression. In the lymph nodes of SS patients at advanced stages of the disease (N2/N3), we also detected an enhancement of IL-18 and a downregulation of IL-1B at the protein level. Moreover, the transcriptomic analysis of the SS and IE nodes confirmed the decreased expression of IL1B and NLRP3, whereas the pathway analysis indicated a further downregulation of IL1B-associated genes. Overall, the present findings showed compartmentalized expressions of IL-1B and IL-18 and provided the first evidence of their imbalance in patients with Sézary syndrome.

Acute gastroenteritis is one of the main causes of mortality and morbidity worldwide, affecting mainly children, the immunocompromised and elderly people. Enteric viruses, especially rotavirus A, are considered important etiological agents, while long-term care facilities are considered favorable environments for the occurrence of sporadic cases and outbreaks of acute gastroenteritis. Therefore, it is important to monitor the viral agents present in nursing homes, especially because studies involving the elderly population in Brazil are scarce, resulting in a lack of available virological data. As a result, the causative agent remains unidentified in a large number of reported acute gastroenteritis cases. However, the advent of next-generation sequencing provides new opportunities for viral detection and discovery. The aim of this study was to identify the viruses that circulate among elderly people with and without acute gastroenteritis, living in residential care homes in Belém, Pará, Brazil, between 2017 and 2019. Ninety-three samples were collected and screened by immunochromatography and qPCR. After, the samples were analyzed individually or in pools by next generation sequencing to identify the viruses circulating in this population. In 26 sequenced samples, members of 13 eukaryotic virus families were identified. The most abundantly present virus families were Parvoviridae, Genomoviridae and Smacoviridae. Contigs displaying similarity to pegiviruses were also detected. Furthermore, a near-complete rotavirus A genome was obtained and could be classified as G3P[8] genotype with the equine DS-1-like genetic background. Complete sequences of the VP4 and VP7 genes of a rotavirus C were also detected, belonging to G4P[2]. This study demonstrates the first characterization of the gastrointestinal virome in elderly in Northern Brazil. A diversity of viruses was found to be present in patients with and without diarrhea, reinforcing the need to monitor elderly people residing in long-term care facilities, especially in cases of acute gastroenteritis.

Type 1 diabetes mellitus (T1D) is caused by partial destruction of the insulin-producing beta cells in the pancreas and is a major issue for public health care worldwide. Reduced or impaired immunological responses, which render patients more susceptible to infections, have been observed in T1D, and this dysfunction is often related to a lack of insulin in the blood. Paracoccidioidomycosis is an important systemic mycosis endemic in Latin America. To evaluate the effects of T1D on this fungal infection and the modulatory effects of insulin, we induced diabetes in C57Bl/6 male mice (alloxan, 60 mg/kg), infected the mice (Pb18, 1 x 10⁶ cells), and treated the mice with neutral protamine Hagedorn (NPH) insulin (2 IU/600 mg/dL blood glucose). Twenty-four hours after infection, infected diabetic mice showed reduced secretion of interferon (IFN)-γ and interleukine (IL)-12 p70 compared to infected nondiabetic controls. On the 45th day of infection, infected diabetic mice presented higher IFN-γ levels, a higher tumor necrosis factor (TNF)-α:IL-10 ratio, and lower adhesion molecule expression levels than nondiabetic mice. In the in vitro experiments, alveolar macrophages from diabetic animals showed reduced phagocytic activity compared to those from control animals at 4, 12, and 24 h. In infected diabetic mice, treatment with insulin restored IL-12 p70 levels at 24 h of infection, reduced IFN-γ levels and the TNF-α:IL-10 ratio at 45 days, and restored vascular cell adhesion molecule (VCAM)-1 expression in pulmonary blood vessels, and this treatment reduced the diminished phosphorylation of extracellular signal-regulated kinases (ERK) and increased nuclear factor-kappa-B(iκb)-α and jun amino-terminal kinases (JNK) p46 levels in infected nondiabetic mice. In addition, insulin promoted increased phagocytic activity in the alveolar macrophages of diabetic mice. These data suggest that T1D mice are more susceptible to Pb18 infection and that insulin modulates this inflammation in diabetic mice by augmenting the expression of adhesion molecules and leukocytes in the lungs and by reducing chronic inflammation.

Purpose: Cutaneous manifestations of SARS-CoV-2 infection exhibit significant variability, yet the role of innate immune responses in the skin of COVID-19 patients remains poorly understood. In this study, we investigated the transcriptomic profile of skin samples from patients who succumbed to COVID-19. Patients and Methods: Skin autopsies from COVID-19 patients with post-mortem time of less than 20 hours were obtained from University of São Paulo Medical School Hospital and healthy skin samples, were submitted to RNA sequencing analysis. Validation of differentially expressed genes (DEGs) was performed by real-Time PCR. Results: Our analysis revealed markedly elevated expression of type I interferon (IFN)-inducible antiviral factors, antioxidant enzymes, and components of several cytokine-signaling pathways in COVID-19 skin samples compared to healthy controls. SARS-CoV-2 infection robustly induced numerous interferon-stimulated genes (ISGs), IFITs, IRF, S100 family with a notable enrichment of those associated with antiviral and inflammatory responses. Moreover, the presence of counter-regulatory factors such as SOCS3 and NFKBIA indicate the involvement of anti-inflammatory mechanisms in the skin. Furthermore, deconvolution data indicated increased presence of macrophages other nucleated cells in vessels in the skin of COVID-19 patients, highlighting the involvement of innate immune mechanisms. Conclusion: The results revealed cutaneous alterations in the expression of genes associated with innate immunity and inflammation factors. This suggests that, unlike tissues with viral tropism, the skin is enriched with antiviral factors to defend against SARS-CoV-2. This information could be useful for developing specific antiviral therapies.