Neuroinflammation (NI) plays a critical role in the pathogenesis of various neurological diseases, including sepsis, which can lead to neuronal damage. The blood–brain barrier (BBB) is essential for regulating NI, as it limits the influx of inflammatory cells and mediators from the periphery into the central nervous system (CNS).Herein, we developed a static blood–brain barrier-on-a-chip (BBBCh) model using a native extracellular matrix (ECM) membrane composed of collagen I (Col I) as the cell-culture surface, on which murine astrocytes, pericytes, microglia, and endothelial cells were co-cultured. The functionality of the BBBCh and the interactions between its components were characterized under naïve and inflammatory conditions. This BBBCh restricted the diffusion of 10- and 40-kDa dextran/fluorescein and allowed the expression of zonula occludens-1 (ZO-1), claudin-5 (Clau-5), and nidogen. An inflamed BBBCh was induced using lipopolysaccharide (LPS), which increased dextran/fluorescein permeability, reduced Clau-5 expression, and elicited a cytokine secretion profile similar to that observed during septic shock. Dexamethasone (Dexa) administration restored BBBCh permeability, Clau-5 expression, and TNF-α and IL-6 concentrations to their basal levels.The developed platform provides a reliable and biomimetic method for studying the pathophysiology of the BBB and its components during neuroinflammation, which could be used to identify novel anti-inflammatory drugs.

BackgroundBacterial lysates have been associated with improved host defense against respiratory infections; however, their mechanisms of action remain incompletely understood. Based on our previous in vitro work showing that Pulmonarom® activates human monocyte-derived dendritic cells (moDCs) and induces TLR- and cytokine-related responses consistent with innate immune activation, we evaluated its immunomodulatory effect during influenza A virus infection using two in vitro conditions: pre-exposure and post-infection treatment.Materials and methodsHuman monocytes obtained from buffy coats were differentiated into moDCs. Lyophilized Pulmonarom® was quantified as total protein and evaluated at 0.01, 0.1, or 0.5 µg/mL in 24-well cultures containing 1 × 106 moDCs in 1 mL medium per well. In the pre-exposure condition, moDCs were incubated with Pulmonarom® for 1 h before infection with influenza A/H1N1 or A/H3N2 virus. In the post-infection treatment condition, Pulmonarom® was added after the 1-h infection period. TLRs and cytokine expression were evaluated by flow cytometry. Changes in hemagglutinating activity were evaluated by hemagglutination inhibition assay and virus infectivity was evaluated with a MDCK plaque cell assay.ResultsUnder both pre-exposure and post-infection treatment conditions, Pulmonarom® enhanced MHC class II expression and improved cell viability following infection with either A/H1N1 or A/H3N2 virus, consistent with moDC activation. In hemagglutination inhibition assays, Pulmonarom® was associated with reduced hemagglutinating activity in culture supernatants. Similarly, plaque infectivity assays demonstrated that Pulmonarom®, administered either before or after infection, decreased the number of lysed cells within plaques, with a more pronounced effect observed under post-infection treatment. These immunomodulatory changes were accompanied by increased cytokine secretion and the induction of type I interferon-related responses.ConclusionsPulmonarom® modulated human moDC responses during in vitro infection with influenza A/H1N1 and A/H3N2 virus. These findings extend our previous observations on Pulmonarom®-induced innate immune activation in human dendritic cells and support further analysis of this bacterial lysate as a host-directed immunomodulatory strategy. Future studies should be evaluated to determine infectious viral titers, TLRs dependency, dendritic-cell maturation markers, and downstream T-cell responses; using plaque assay with sensible cells, receptor-blocking approaches, expanded maturation and characterization panels, and functional co-culture assays.

OBJECTIVE:COVID-19 has been associated with a wide range of systemic and neurological complications, known as long COVID or postacute sequelae of COVID-19 (PASC). Such sequelae can be observed among all infected individuals, even among those with a mild disease course. Dysbiosis, a common condition associated with low-grade inflammation, has been proposed as a potential mechanism of PASC by altering levels of circulating lipopolysaccharide (LPS) and the tryptophan pathway metabolites kynurenine and quinolinic acid, known to affect neurocognitive function. The authors evaluated the evolution of neurological, neurocognitive, and neuropsychiatric COVID-19 sequelae and their relationship with circulating LPS and kynurenine and quinolinic acid levels. METHODS:A prospective, longitudinal, and analytical study was conducted. Neurological, neurocognitive, and neuropsychiatric assessments of participants who had recovered from COVID-19 and did not require hospitalization during the acute stages of the infection were performed. Peripheral levels of LPS and tryptophan metabolites were measured 1, 3, 6, and 12 months after infection. RESULTS:Of 95 participants recruited, 67 COVID-19-convalescent individuals and 20 COVID-19-free individuals were included. Significantly higher occurrences of asthenia, olfaction and taste alterations, headache, memory dysfunction, and systemic symptoms such as dyspnea, cough, and periodontal diseases were found among participants in the COVID-19-convalescent group compared with participants in the comparison group. A significant decrease in kynurenine levels, which correlated with cognitive impairment, was observed among PASC convalescents. CONCLUSIONS:Significant neurocognitive and neuropsychiatric impairments were observed among COVID-19-convalescent individuals, along with decreased kynurenine levels, which recovered during a 12-month follow-up period.

Peptide drugs have emerged as an attractive alternative for cancer treatment due to their potency, high specificity, general safety and low cost. GK-1 is a linear 18 amino acid peptide with proven immunomodulator, antitumor and antimetastatic capacity in animal models. Preclinical toxicity studies for its use as a vaccine adjuvant demonstrated its safety in various assay systems, but a comprehensive exploration of its toxicity profile is required to be used in cancer immunotherapy. Therefore, in the present work, the potential toxicity of GK-1 was predicted with ToxinPred 3.0 software, and its in vitro cytotoxicity, and single-dose and repeated-dose toxicity by subcutaneous route in mice were experimentally assessed. GK-1 peptide was predicted as a non-toxic and did not exhibit in vitro cytotoxicity for several non-tumor and tumor cell lines and primary cell cultures at concentrations up to 500 µM, reinforcing previous studies pointing that the antitumoral effect of GK-1 was not mediated by tumor cell cytotoxicity. The single-dose toxicity study did not evidence local or systemic toxicity up to the maximum tested dose of 1000 mg/kg. Moreover, no toxic effects were observed in the repeated-dose toxicity study based on four doses administered weekly at up to 300 mg/kg. Considering that GK-1 is effective in triple-negative breast cancer and melanoma models in mice at doses as low as 5 mg/kg, the present results support the safety of GK-1 as an antitumoral peptide candidate.

Neurocysticercosis is caused by the establishment of Taenia solium cysticerci in the central nervous system. The extraparenchymal form (ExP-NCC) is the most severe clinical presentation that may remain asymptomatic for years. Current treatment involves cysticidal drugs (albendazole and/or praziquantel) combined with glucocorticoids to manage the associated neuroinflammation; however, only ∼30% of patients respond effectively. This highlights the need to improve therapeutic strategies. Herein, the experimental murine model of human ExP-NCC was further characterized to improve its usefulness in testing new therapies. In humans, cysts grow slowly in the basal cisterns of the subarachnoid space, and patients become symptomatic years after the infection. Thus, a long-term follow-up was performed by using magnetic resonance imaging (MRI) with sequences allowing volumetric analysis. MRI confirmed NCC in 77% of infected rats, all exhibiting extraparenchymal localization and persistently elevated levels of HP10, a marker of viable cysticerci. Imaging also enabled precise cyst localization and estimation of the parasite-occupied volume.

This study evaluated the anti-amoebic properties of aqueous extracts of two Carica papaya callus clones, Wild Type (Pcc-WT-AE) and KETc7-expressing (Pcc-KETc7-AE) clones, in in vitro and in vivo assays. E. histolytica trophozoites cultures were exposed for 24 h to varying concentrations of the C. papaya aqueous extracts, and their viability and IC50 determined by MTT assays. In in vivo studies, golden hamsters were infected intraportally with E. histolytica trophozoites and orally treated with the C. papaya aqueous extracts for 7 days. The animals were sacrificed on day 8, and the development of ALA was recorded. Comparisons were made against metronidazole (MTZ). Both extracts statistically reduced trophozoite viability at 24 h in a dose-dependent manner in vitro. Pcc-KETc7-AE showed activity to the same extent as MTZ (IC50 36.08 µg/ml vs. 33.54 µg/ml, respectively), whereas Pcc-WT-AE exhibited less efficient but significant activity (IC50 113.4 µg/ml). Cell death analysis indicated that both extracts killed trophozoites by necrosis. In vivo studies showed that oral treatment with Pcc-WT-AE (4 and 8 mg/dose/hamster) completely prevented ALA development in 80

BACKGROUND:Parasitic infections of the central nervous system (CNS) represent a considerable health burden in low- and middle-income countries. During chronic disease, parasites modulate host immunity to ensure long-term persistence while limiting collateral tissue damage. A key feature of this immune remodeling is the progressive T-cell dysfunction that may culminate in T-cell exhaustion, characterized by increased expression of inhibitory receptors (TIM-3, LAG-3, KLRG1), checkpoint molecules (PD-1, PD-L1), suppressor of cytokine signaling-1 (SOCS1), and arginase-1. SUMMARY:The relevance of the neuroimmune-endocrine (NIE) axis on the modulation of T-cell dysfunction related to parasite survival needs to be explored. This review focuses on two parasitic CNS infections: neurotoxoplasmosis induced by the intracellular protozoan Toxoplasma gondii and neurocysticercosis caused when cysticercus of the cestode Taenia solium lodges in the CNS. KEY MESSAGES:We present updated evidence on how these phylogenetically distant pathogens exploit the NIE network, describe the physiological consequences for the host, and highlight shared and distinct mechanisms behind T-cell exhaustion. Finally, we address emerging immunotherapeutic strategies aimed at reversing exhaustion and restoring protective immunity.

Background: Multiple sclerosis (MS) is a demyelinating, neuroinflammatory, progressive disease that severely affects human health of young adults. Neuroinflammation (NI) and demyelination, as well as their interactions, are key therapeutic targets to halt or slow disease progression. Potent steroidal anti-inflammatory drugs such as methylprednisolone (MP) and remyelinating neurosteroids such as allopregnanolone (ALLO) could be co-administered intranasally to enhance their efficacy by providing direct access to the central nervous system (CNS). Methods: The individual and combined effects of MP and ALLO to control the clinical score of murine experimental autoimmune encephalitis (EAE), to preserve spinal cord tissue integrity, modulate cellular infiltration and gliosis, promote remyelination, and modify the expression of Aryl hydrocarbon receptor (AhR) were evaluated. In silico studies, to deep insight into the mechanisms involved for the treatments, were also conducted. Results: MP was the only treatment that significantly reduced the EAE severity, infiltration of inflammatory cells and ionized calcium-binding adapter molecule 1 (Iba-1) expression respect to those EAE non-treated mice but with no-significant differences between the three treatments. MP, ALLO and MP+ALLO significantly reduced tissue damage, AhR expression, and promoted remyelination. Overall, these results suggest that MP, with or without the co-administration with ALLO is an effective and safe strategy to reduce the inflammatory status and the progression of EAE. Despite the expectations of the use of ALLO to reduce the inflammation in EAE, its effect in the dose-scheme used herein is limited only to improve myelination, an effect that supports its usefulness in demyelinating diseases. These results indicate the interest in exploring different doses of ALLO to recommend its use. Conclusions: ALLO treatment mainly maintain the integrity of the spinal cord tissue and the presence of myelin without affecting NI and the clinical outcome. AhR could be involved in the effect observed in both, MP and ALLO treatments. These results will help in the development of a more efficient therapy for MS patients.

BACKGROUND:SARS-CoV2 induces flu-like symptoms that can rapidly progress to severe acute lung injury and even death. The virus also invades the central nervous system (CNS), causing neuroinflammation and death from central failure. Intravenous (IV) or oral dexamethasone (DXM) reduced 28 d mortality in patients who required supplemental oxygen compared to those who received conventional care alone. Through these routes, DMX fails to reach therapeutic levels in the CNS. In contrast, the intranasal (IN) route produces therapeutic levels of DXM in the CNS, even at low doses, with similar systemic bioavailability. AIMS:To compare IN vs. IV DXM treatment in hospitalized patients with COVID-19. METHODS:A controlled, multicenter, open-label trial. Patients with COVID-19 (69) were randomly assigned to receive IN-DXM (0.12 mg/kg for three days, followed by 0.6 mg/kg for up to seven days) or IV-DXM (6 mg/d for 10 d). The primary outcome was clinical improvement, as defined by the National Early Warning Score (NEWS) ordinal scale. The secondary outcome was death at 28 d between IV and IN patients. Effects of both treatments on biochemical and immunoinflammatory profiles were also recorded. RESULTS:Initially, no significant differences in clinical severity, biometrics, and immunoinflammatory parameters were found between both groups. The NEWS-2 score was reduced, in 23 IN-DXM treated patients, with no significant variations in the 46 IV-DXM treated ones. Ten IV-DXM-treated patients and only one IN-DXM patient died. CONCLUSIONS:IN-DMX reduced NEWS-2 and mortality more efficiently than IV-DXM, suggesting that IN is a more efficient route of DXM administration.

By end December of 2021, COVID-19 has infected around 276 million individuals and caused over 5 million deaths worldwide. Infection results in dysregulated systemic inflammation, multi-organ dysfunction, and critical illness. Cells of the central nervous system are also affected, triggering an uncontrolled neuroinflammatory response. Low doses of glucocorticoids, administered orally or intravenously, reduce mortality among moderate and severe COVID-19 patients. However, low doses administered by these routes do not reach therapeutic levels in the CNS. In contrast, intranasally administered dexamethasone can result in therapeutic doses in the CNS even at low doses. This is an approved open-label, multicenter, randomized controlled trial to compare the effectiveness of intranasal versus intravenous dexamethasone administered in low doses to moderate and severe COVID-19 adult patients. The protocol is conducted in five health institutions in Mexico City. A total of 120 patients will be randomized into two groups (intravenous vs. intranasal) at a 1:1 ratio. Both groups will be treated with the corresponding dexamethasone scheme for 10 days. The primary outcome of the study will be clinical improvement, defined as a statistically significant reduction in the NEWS-2 score of patients with intranasal versus intravenous dexamethasone administration. The secondary outcome will be the reduction in mortality during hospitalization. This protocol is currently in progress to improve the efficacy of the standard therapeutic dexamethasone regimen for moderate and severe COVID-19 patients. ClinicalTrials.gov NCT04513184 . Registered November 12, 2020. Approved by La Comisión Federal para la Protección contra Riesgos Sanitarios (COFEPRIS) with identification number DI/20/407/04/36. People are currently being recruited.

INTRODUCTION:Neuroinflammation is involved in the pathophysiology of various neurological disorders, in particular Alzheimer disease (AD) and Parkinson's disease (PD). Alterations in the blood-brain barrier may allow peripheral blood lymphocytes to enter the central nervous system; these may participate in disease pathogenesis. OBJECTIVE:To evaluate the peripheral blood lymphocyte profiles of patients with AD and PD and their association with the disease and its progression. METHODS:The study included 20 patients with AD, 20 with PD, and a group of healthy individuals. Ten of the patients with AD and 12 of those with PD were evaluated a second time 17 to 27 months after the start of the study. Lymphocyte subpopulations and their activation status were determined by flow cytometry. All patients underwent neurological examinations using internationally validated scales. RESULTS:Compared to healthy individuals, patients with AD and PD showed significantly higher levels of activated lymphocytes, lymphocytes susceptible to apoptosis, central memory T cells, and regulatory T and B cells. As the diseases progressed, there was a significant decrease in activated cells (CD4+ CD38+ and CD8+ CD38+ in PD and AD, CD4+ CD69+ and CD8+ CD69+ in PD), T cells susceptible to apoptosis, and some regulatory populations (CD19+ CD5+ IL10+ in PD and AD, CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ in PD). In patients with AD, disease progression was associated with lower percentages of CD4+ CD38+ cells and higher percentages of effector CD4 cells at the beginning of the study. Significant differences were observed between both diseases. CONCLUSIONS:This study provides evidence of changes in peripheral blood lymphocyte phenotypes associated with AD and PD and their severity. Considering effective blood-brain communication, our results open new avenues of research into immunomodulation therapies to treat these diseases.

Relapsing-remitting multiple sclerosis, the most common form, is characterized by acute neuroinflammatory episodes. In addition to continuous disease-modifying therapy, these relapses require treatment to prevent lesion accumulation and progression of disability. Intravenous methylprednisolone (1-2 g for 3-5 days) is the standard treatment for relapses. However, this treatment is invasive, requires hospitalization, leads to substantial systemic exposure of glucocorticoids, and can only reach modest concentrations in the central nervous system (CNS). Intranasal delivery may represent an alternative to deliver relapse treatment directly to the CNS with higher concentrations and reducing side effects. Histopathological analysis revealed that intranasal administration of methylprednisolone to mice with experimental autoimmune encephalomyelitis (EAE) suppressed the neuroinflammatory peak, and reduced immune cell infiltration and demyelination in the CNS similarly to intravenous administration. Treatment also downregulated Iba1 and GFAP expression. A similar significant reduction of IL-1β, IL-6, IL-17, IFN-γ, and TNF-α levels in the spinal cord was attained in both intranasal and intravenously treated mice. No damage in the nasal cavity was found after intranasal administration. This study demonstrates that intranasal delivery of methylprednisolone is as efficient as the intravenous route to treat neuroinflammation in EAE.

Sepsis occurs when a systemic infection induces an uncontrolled inflammatory response that results in generalized organ dysfunction. The exacerbated peripheral inflammation can induce, in turn, neuroinflammation which may result in severe impairment of the central nervous system (CNS). Indeed, the ensuing blood–brain barrier disruption associated with sepsis promotes glial activation and starts a storm of proinflammatory cytokines in the CNS that leads to brain dysfunction in sepsis survivors. Endotoxic shock induced in mice by peripheral injection of lipopolysaccharides closely resembles the peripheral and central inflammation observed in sepsis. In this review, we provide an overview of the neuroinflammatory features in sepsis and of recent progress toward the development of new anti-neuroinflammatory therapies seeking to reduce mortality and morbidity in sepsis survivors.

Low cost vaccines against cysticercosis are needed to fight this parasitosis, especially in developing countries. Herein polycistron arrangements were designed to accomplish the simultaneous expression of multiple protective antigens from Taenia solium in the plant cell as an attractive biofactory and delivery vehicle of vaccines. Transplastomic plants carrying synthetic polycistrons were able to simultaneously express the KETc1, KETc7, KETc12, GK1, and TSOL18/HP6-Tsol antigens; which retained their antigenicity and ability to induce humoral responses in BALB/c mice. These clones may be useful for the production of low-cost cysticercosis vaccine prototypes.

To fulfill its function, the immune system must detect and interpret a wide variety of signals and adjust the magnitude, duration, and specific traits of each response during the complex host-parasite relationships in parasitic infections. Inflammation must be tightly regulated since uncontrolled inflammation may be as destructive as the triggering stimulus and leads to immune-mediated tissue injury. During recent years, increasing evidence points to regulatory T cells (Tregs) as key anti-inflammatory cells, critically involved in limiting the inflammatory response. Herein, we review the published information on the induction of Tregs and summarize the most recent findings on Treg generation in parasitic diseases.

Taenia solium cysticercosis is a major parasitic disease that seriously and frequently affects human health and economy in undeveloped countries. Since pigs are an indispensable intermediate host, it is conceivable to curb transmission by reducing pig cysticercosis through their effective vaccination. This article reviews current knowledge on the development vaccines against porcine cysticercosis. It highlights the development of several versions of S3Pvac aimed to increase effectiveness, reduce costs and increase feasibility by novel delivery systems and alternative routes of administration.

Brucella lumazine synthase (BLS) has been previously used with success as a delivery system for systemic immunization against murine cysticercosis. We herein determined the usefulness of BLS as a new antigen-delivery system and mucosal-adjuvant using KETc1, one of the peptides of the anti-cysticercosis vaccine. A protection of up to 98% was induced when KETc1 was used as a chimera fused to BLS. Used as adjuvant of KETc1, BLS also induced a high level of protection (79%), which did not significantly differ from that induced by the cholera toxin (74%). KETc1 and BLS administered separately also reduced the parasite load. KETc1 administered orally as a chimera, and to a lesser extent with BLS as adjuvant, elicited IgG and IgA specific antibodies, which were detectable both in fecal extracts and in sera, and increased B and CD4 activated cells. BLS-KETc1 also increased the levels of transcription of TNF-α, IL-2 and IFNγ in Peyer's patches, and in spleen, only increased TNF-α was observed. Overall, these results showed that BLS can be used as both an antigen-carrier and as an adjuvant in the design of new oral subunit vaccines.