Immunotherapy with oral administration of humanized anti-CD3 monoclonal antibody: a novel gut-immune system-based therapy for metaflammation and NASH

The PD-1/PD-L1 Axis in the Biology of MASLD

Metabolic Dysfunction-Associated Steatotic Liver (MASL), previously named nonalcoholic fatty liver (NAFL), is a multifactorial disease in which metabolic, genetic, and environmental risk factors play a predominant role. Obesity and type 2 diabetes act as triggers of the inflammatory response, which contributes to the progression of MASL to Metabolic Dysfunction-Associated Steatohepatitis and the development of hepatocellular carcinoma. In the liver, several parenchymal, nonparenchymal, and immune cells maintain immunological homeostasis, and different regulatory pathways balance the activation of the innate and adaptative immune system. PD-1/PD-L1 signaling acts, in the maintenance of the balance between the immune responses and the tissue immune homeostasis, promoting self-tolerance through the modulation of activated T cells. Recently, PD-1 has received much attention for its roles in inducing an exhausted T cells phenotype, promoting the tumor escape from immune responses. Indeed, in MASLD, the excessive fat accumulation dysregulates the immune system, increasing cytotoxic lymphocytes and decreasing their cytolytic activity. In this context, T cells exacerbate liver damage and promote tumor progression. The aim of this review is to illustrate the main pathogenetic mechanisms by which the immune system promotes the progression of MASLD and the transition to HCC, as well as to discuss the possible therapeutic applications of PD-1/PD-L1 target therapy to activate T cells and reinvigorate immune surveillance against cancer.

Suppression of anti-drug antibody formation against coagulation factor VIII by oral delivery of anti-CD3 monoclonal antibody in hemophilia A mice

Active tolerance to ingested dietary antigens forms the basis for oral immunotherapy to food allergens or autoimmune self-antigens. Alternatively, oral administration of anti-CD3 monoclonal antibody can be effective in modulating systemic immune responses without T cell depletion. Here we assessed the efficacy of full length and the F(ab')2 fragment of oral anti-CD3 to prevent anti-drug antibody (ADA) formation to clotting factor VIII (FVIII) protein replacement therapy in hemophilia A mice. A short course of low dose oral anti-CD3 F(ab')2 reduced the production of neutralizing ADAs, and suppression was significantly enhanced when oral anti-CD3 was timed concurrently with FVIII administration. Tolerance was accompanied by the early induction of FoxP3+LAP-, FoxP3+LAP+, and FoxP3-LAP+ populations of CD4+ T cells in the spleen and mesenteric lymph nodes. FoxP3+LAP+ Tregs expressing CD69, CTLA-4, and PD1 persisted in spleens of treated mice, but did not produce IL-10. Finally, we attempted to combine the anti-CD3 approach with oral intake of FVIII antigen (using our previously established method of using lettuce plant cells transgenic for FVIII antigen fused to cholera toxin B (CTB) subunit, which suppresses ADAs in part through induction of IL-10 producing FoxP3-LAP+ Treg). However, combining these two approaches failed to improve suppression of ADAs. We conclude that oral anti-CD3 treatment is a promising approach to prevention of ADA formation in systemic protein replacement therapy, albeit via mechanisms distinct from and not synergistic with oral intake of bioencapsulated antigen.

Microtubules as a potential platform for energy transfer in biological systems: a target for implementing individualized, dynamic variability patterns to improve organ function

Variability characterizes the complexity of biological systems and is essential for their function. Microtubules (MTs) play a role in structural integrity, cell motility, material transport, and force generation during mitosis, and dynamic instability exemplifies the variability in the proper function of MTs. MTs are a platform for energy transfer in cells. The dynamic instability of MTs manifests itself by the coexistence of growth and shortening, or polymerization and depolymerization. It results from a balance between attractive and repulsive forces between tubulin dimers. The paper reviews the current data on MTs and their potential roles as energy-transfer cellular structures and presents how variability can improve the function of biological systems in an individualized manner. The paper presents the option for targeting MTs to trigger dynamic improvement in cell plasticity, regulate energy transfer, and possibly control quantum effects in biological systems. The described system quantifies MT-dependent variability patterns combined with additional personalized signatures to improve organ function in a subject-tailored manner. The platform can regulate the use of MT-targeting drugs to improve the response to chronic therapies. Ongoing trials test the effects of this platform on various disorders.

Low-Dose Colchicine Attenuates Sepsis-Induced Liver Injury: A Novel Method for Alleviating Systemic Inflammation

Sepsis is a significant public health challenge. The immune system underlies the pathogenesis of the disease. The liver is both an active player and a target organ in sepsis. Targeting the gut immune system using low-dose colchicine is an attractive method for alleviating systemic inflammation in sepsis without inducing immunosuppression. The present study aimed to determine the use of low-dose colchicine in LPS-induced sepsis in mice. C67B mice were injected intraperitoneal with LPS to induce sepsis. The treatment group received 0.02 mg/kg colchicine daily by gavage. Short and extended models were performed, lasting 3 and 5 days, respectively. We followed the mice for biochemical markers of end-organ injury, blood counts, cytokine levels, and liver pathology and conducted proteomic studies on liver samples. Targeting the gut immune system using low-dose colchicine improved mice's well-being measured by the murine sepsis score. Treatment alleviated the liver injury in septic mice, manifested by a significant decrease in their liver enzyme levels, including ALT, AST, and LDH. Treatment exerted a trend to reduce creatinine levels. Low-dose colchicine improved liver pathology, reduced inflammation, and reduced the pro-inflammatory cytokine TNFα and IL1-β levels. A liver proteomic analysis revealed low-dose colchicine down-regulated sepsis-related proteins, alpha-1 antitrypsin, and serine dehydratase. Targeting the gut immune system using low-dose colchicine attenuated liver injury in LPS-induced sepsis, reducing the pro-inflammatory cytokine levels. Low-dose colchicine provides a safe method for immunomodulation for multiple inflammatory disorders.

Treating inflammation to combat non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) with its more progressive form non-alcoholic steatohepatitis (NASH) has become the most common chronic liver disease, thereby representing a great burden for patients and healthcare systems. Specific pharmacological therapies for NAFLD are still missing. Inflammation is an important driver in the pathogenesis of NASH, and the mechanisms underlying inflammation in NAFLD represent possible therapeutic targets. In NASH, various intra- and extrahepatic triggers involved in the metabolic injury typically lead to the activation of different immune cells. This includes hepatic Kupffer cells, i.e. liver-resident macrophages, which can adopt an inflammatory phenotype and activate other immune cells by releasing inflammatory cytokines. As inflammation progresses, Kupffer cells are increasingly replaced by monocyte-derived macrophages with a distinct lipid-associated and scar-associated phenotype. Many other immune cells, including neutrophils, T lymphocytes - such as auto-aggressive cytotoxic as well as regulatory T cells - and innate lymphoid cells balance the progression and regression of inflammation and subsequent fibrosis. The detailed understanding of inflammatory cell subsets and their activation pathways prompted preclinical and clinical exploration of potential targets in NAFLD/NASH. These approaches to target inflammation in NASH include inhibition of immune cell recruitment via chemokine receptors (e.g. cenicriviroc), neutralization of CD44 or galectin-3 as well as agonism to nuclear factors like peroxisome proliferator-activated receptors and farnesoid X receptor that interfere with the activation of immune cells. As some of these approaches did not demonstrate convincing efficacy as monotherapies, a rational and personalized combination of therapeutic interventions may be needed for the near future.

The immune response as a therapeutic target in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a complex and heterogeneous disorder considered a liver-damaging manifestation of metabolic syndrome. Its prevalence has increased in the last decades due to modern-day lifestyle factors associated with overweight and obesity, making it a relevant public health problem worldwide. The clinical progression of NAFLD is associated with advanced forms of liver injury such as fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). As such, diverse pharmacological strategies have been implemented over the last few years, principally focused on metabolic pathways involved in NAFLD progression. However, a variable response rate has been observed in NAFLD patients, which is explained by the interindividual heterogeneity of susceptibility to liver damage. In this scenario, it is necessary to search for different therapeutic approaches. It is worth noting that chronic low-grade inflammation constitutes a central mechanism in the pathogenesis and progression of NAFLD, associated with abnormal composition of the intestinal microbiota, increased lymphocyte activation in the intestine and immune effector mechanisms in liver. This review aims to discuss the current knowledge about the role of the immune response in NAFLD development. We have focused mainly on the impact of altered gut-liver-microbiota axis communication on immune cell activation in the intestinal mucosa and the role of subsequent lymphocyte homing to the liver in NAFLD development. We further discuss novel clinical trials that addressed the control of the liver and intestinal immune response to complement current NAFLD therapies.

Immune mechanisms linking metabolic injury to inflammation and fibrosis in fatty liver disease - novel insights into cellular communication circuits

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease and is emerging as the leading cause of cirrhosis, liver transplantation and hepatocellular carcinoma (HCC). NAFLD is a metabolic disease that is considered the hepatic manifestation of the metabolic syndrome; however, during the evolution of NAFLD from steatosis to non-alcoholic steatohepatitis (NASH), to more advanced stages of NASH with liver fibrosis, the immune system plays an integral role. Triggers for inflammation are rooted in hepatic (lipid overload, lipotoxicity, oxidative stress) and extrahepatic (gut-liver axis, adipose tissue, skeletal muscle) systems, resulting in unique immune-mediated pathomechanisms in NAFLD. In recent years, the implementation of single-cell RNA-sequencing and high dimensional multi-omics (proteogenomics, lipidomics) and spatial transcriptomics have tremendously advanced our understanding of the complex heterogeneity of various liver immune cell subsets in health and disease. In NAFLD, several emerging inflammatory mechanisms have been uncovered, including profound macrophage heterogeneity, auto-aggressive T cells, the role of unconventional T cells and platelet-immune cell interactions, potentially yielding novel therapeutics. In this review, we will highlight the recent discoveries related to inflammation in NAFLD, discuss the role of immune cell subsets during the different stages of the disease (including disease regression) and integrate the multiple systems driving inflammation. We propose a refined concept by which the immune system contributes to all stages of NAFLD and discuss open scientific questions arising from this paradigm shift that need to be unravelled in the coming years. Finally, we discuss novel therapeutic approaches to target the multiple triggers of inflammation, including combination therapy via nuclear receptors (FXR agonists, PPAR agonists).

Alternative Routes of Administration for Therapeutic Antibodies—State of the Art

Background: For the past two decades, there has been a huge expansion in the development of therapeutic antibodies, with 6 to 10 novel entities approved each year. Around 70% of these Abs are delivered through IV injection, a mode of administration allowing rapid and systemic delivery of the drug. However, according to the evidence presented in the literature, beyond the reduction of invasiveness, a better efficacy can be achieved with local delivery. Consequently, efforts have been made toward the development of innovative methods of administration, and in the formulation and engineering of novel Abs to improve their therapeutic index. Objective: This review presents an overview of the routes of administration used to deliver Abs, different from the IV route, whether approved or in the clinical evaluation stage. We provide a description of the physical and biological fundamentals for each route of administration, highlighting their relevance with examples of clinically-relevant Abs, and discussing their strengths and limitations. Methods: We reviewed and analyzed the current literature, published as of the 1 April 2022 using MEDLINE and EMBASE databases, as well as the FDA and EMA websites. Ongoing trials were identified using clinicaltrials.gov. Publications and data were identified using a list of general keywords. Conclusions: Apart from the most commonly used IV route, topical delivery of Abs has shown clinical successes, improving drug bioavailability and efficacy while reducing side-effects. However, additional research is necessary to understand the consequences of biological barriers associated with local delivery for Ab partitioning, in order to optimize delivery methods and devices, and to adapt Ab formulation to local delivery. Novel modes of administration for Abs might in fine allow a better support to patients, especially in the context of chronic diseases, as well as a reduction of the treatment cost.

The role of bacterial translocation in sepsis: a new target for therapy

Sepsis is a leading cause of death in critically ill patients, primarily due to multiple organ failures. It is associated with a systemic inflammatory response that plays a role in the pathogenesis of the disease. Intestinal barrier dysfunction and bacterial translocation (BT) play pivotal roles in the pathogenesis of sepsis and associated organ failure. In this review, we describe recent advances in understanding the mechanisms by which the gut microbiome and BT contribute to the pathogenesis of sepsis. We also discuss several potential treatment modalities that target the microbiome as therapeutic tools for patients with sepsis.

PD-1/PD-L1 Immuno-Mediated Therapy in NAFLD: Advantages and Obstacles in the Treatment of Advanced Disease

Non-alcoholic fatty liver disease (NAFLD) is characterized by an enhanced activation of the immune system, which predispose the evolution to nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). Resident macrophages and leukocytes exert a key role in the pathogenesis of NAFLD. In particular, CD4+ effector T cells are activated during the early stages of liver inflammation and are followed by the increase of natural killer T cells and of CD8+ T cytotoxic lymphocytes which contribute to auto-aggressive tissue damage. To counteract T cells activation, programmed cell death 1 (PD-1) and its ligand PDL-1 are exposed respectively on lymphocytes and liver cells’ surface and can be targeted for therapy by using specific monoclonal antibodies, such as of Nivolumab, Pembrolizumab, and Atezolizumab. Despite the combination of Atezolizumab and Bevacizumab has been approved for the treatment of advanced HCC, PD-1/PD-L1 blockage treatment has not been approved for NAFLD and adjuvant immunotherapy does not seem to improve survival of patients with early-stage HCC. In this regard, different ongoing phase III trials are testing the efficacy of anti-PD-1/PD-L1 antibodies in HCC patients as first line therapy and in combination with other treatments. However, in the context of NAFLD, immune checkpoints inhibitors may not improve HCC prognosis, even worse leading to an increase of CD8+PD-1+ T cells and effector cytokines which aggravate liver damage. Here, we will describe the main pathogenetic mechanisms which characterize the immune system involvement in NAFLD discussing advantages and obstacles of anti PD-1/PDL-1 immunotherapy.

Non-alcoholic fatty liver disease and intestinal immune status: a narrative review

Background and objectives: Non-alcoholic fatty liver disease (NAFLD) interacts with the gut immunity. However, the mechanisms underlying alternations of intestinal immune system in NAFLD remains unclear. To date, no effective medical interventions exist that completely reverse the disease. In this review, we mainly elaborates on the impact of NAFLD on intestinal immune cells and briefly summarize the new treatment methods for NAFLD targeting at intestinal immune cells.Methods: We searched MEDLINE, EMBASE and Web of Science for English-language sources. The preferred citations were meta-analyses and systematic or narrative reviews. Citation tracking was completed for all identified studies included in the refined library, using Google Scholar. No restriction was placed on the year of publication for the included reports.Results: The intestinal immune imbalance promotes liver inflammation and fibrosis in the process of NAFLD, and meanwhile, NAFLD influences disorders of immune cells in the liver and intestinal tract. Biological agents targeting at intestinal immunity has been shown in preclinical studies to be an effective method for systemic immune modulation and alleviates immune-mediated injury.Conclusions: Intestinal immune disorder plays an important role in triggering and amplifying hepatic inflammation in NAFLD. Advances in knowledge of the gut-liver axis are driving the development of diagnostic, prognostic and therapeutic tools based on intestine immunity for the management of NAFLD.

Formulation of biologics for alternative routes of administration: Current problems and perspectives

Introduction: Biologics (biopharmaceuticals) present new promising therapies for many diseases such as cancers, chronical inflammatory diseases and today's biggest challenge - COVID-19. Research: Today, most biologics have been synthetized using modern methods of biotechnology, in particular DNA recombinant technology. Current pharmaceutical forms of protein/peptide biopharmaceuticals are intended for parenteral route of administration due to their instability and large size of molecules. In order to improve patient compliance, many companies are working on developing adequate forms of biopharmaceuticals for alternative, non-invasive routes of administration. The aim of this work is to review current aspirations and problems in formulation of biopharmaceuticals for alternative (non-parenteral) routes of administration and to review the attempts to overcome them. These alternative routes of administration could be promising in prevention and treatment of COVID-19, among other serious diseases. Conclusion: The emphasis is on stabilizing monoclonal antibodies into special formulations and delivery systems; their application should be safer, more comfortable and reliable. When it comes to hormones, vaccines and smaller peptides, some companies have already registered drugs intended for nasal and oral delivery.

Inflammation and Fibrogenesis in MAFLD: Role of the Hepatic Immune System

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) is the definition recently proposed to better circumscribe the spectrum of conditions long known as non-alcoholic fatty liver disease (NAFLD) that range from simple steatosis without inflammation to more advanced liver diseases. The progression of MAFLD, as well as other chronic liver diseases, toward cirrhosis, is driven by hepatic inflammation and fibrogenesis. The latter, result of a “chronic wound healing reaction,” is a dynamic process, and the understanding of its underlying pathophysiological events has increased in recent years. Fibrosis progresses in a microenvironment where it takes part an interplay between fibrogenic cells and many other elements, including some cells of the immune system with an underexplored or still unclear role in liver diseases. Some therapeutic approaches, also acting on the immune system, have been probed over time to evaluate their ability to improve inflammation and fibrosis in NAFLD, but to date no drug has been approved to treat this condition. In this review, we will focus on the contribution of the liver immune system in the progression of NAFLD, and on therapies under study that aim to counter the immune substrate of the disease.

CAR Treg: A new approach in the treatment of autoimmune diseases

Regulatory T cells (Tregs) have the role of regulating self-tolerance, and suppressing immune responses. Defects in Treg function and number can lead to in loss of tolerance or autoimmune disease. To treat or control autoimmune diseases, one of the options is to develop immune tolerance for Tregs cell therapy, which includes promotion and activation. Recently, cell-based treatment as a promising approach to increase cells function and number has been developed. Cell therapy by chimeric T antigen receptor (CAR-T) cells has shown significant efficacy in the treatment of leukemia, which has led researchers to use CAR-T cells in other diseases like autoimmune diseases. Here, we describe the existing treatments for autoimmune diseases and the available treatments based on Treg, their benefits and restrictions for implementation in clinical trials. We also discussed potential solutions to overcome these limitations. It seems novel designs of CARs to be new hope for autoimmune diseases and expected to be a potential cure option in a wide array of disease in the future. Therefore, it is very important to address this issue and increase information about it.

Steatosis, Steatohepatitis and Cancer Immunotherapy: An Intricate Story

Immune checkpoint inhibitors represent one of the most significant recent advances in clinical oncology, since they dramatically improved the prognosis of deadly cancers such as melanomas and lung cancer. Treatment with these drugs may be complicated by the occurrence of clinically-relevant adverse drug reactions, most of which are immune-mediated, such as pneumonitis, colitis, endocrinopathies, nephritis, Stevens Johnson syndrome and toxic epidermal necrolysis. Drug-induced steatosis and steatohepatitis are not included among the typical forms of cancer immunotherapy-induced liver toxicity, which, instead, usually occurs as a panlobular hepatitis with prominent lymphocytic infiltrates. Nonetheless, non-alcoholic fatty liver disease is a risk factor for immunotherapy-induced hepatitis, and steatosis and steatohepatitis are frequently observed in this condition. In the present review we discuss how these pathology findings could be explained in the context of current models suggesting immune-mediated pathogenesis for steatohepatitis. We also review evidence suggesting that in patients with hepatocellular carcinoma, the presence of steatosis or steatohepatitis could predict a poor therapeutic response to these agents. How these findings could fit with immune-mediated mechanisms of these liver diseases will also be discussed.

Carminic acid mitigates fructose-triggered hepatic steatosis by inhibition of oxidative stress and inflammatory reaction

Excessive fructose (Fru) consumption has been reported to favor nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanism is still elusive, lacking effective therapeutic strategies. Carminic acid (CA), a glucosylated anthraquinone found in scale insects like Dactylopius coccus, exerts anti-tumor and anti-oxidant activities. Nevertheless, its regulatory role in Fru-induced NAFLD is still obscure. Here, the effects of CA on NAFLD in Fru-challenged mice and the underlying molecular mechanisms were explored. We found that Fru intake significantly led to insulin resistance and dyslipidemia in liver of mice, which were considerably attenuated by CA treatment through repressing endoplasmic reticulum (ER) stress. Additionally, inflammatory response induced by Fru was also attenuated by CA via the blockage of nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs) and tumor necrosis factor α/TNF-α receptor (TNF-α/TNFRs) signaling pathways. Moreover, Fru-provoked oxidative stress in liver tissues was remarkably attenuated by CA mainly through improving the activation of nuclear factor erythroid 2-related factor 2 (Nrf-2). These anti-dyslipidemias, anti-inflammatory and anti-oxidant activities regulated by CA were confirmed in the isolated primary hepatocytes with Fru stimulation. Importantly, the in vitro experiments demonstrated that Fru-induced lipid accumulation was closely associated with inflammatory response and reactive oxygen species (ROS) production regulated by TNF-α and Nrf-2 signaling pathways, respectively. In conclusion, these results demonstrated that CA could be considered as a potential therapeutic strategy to attenuate metabolic disorder and NAFLD in Fru-challenged mice mainly through suppressing inflammatory response and oxidative stress.

A digital health platform for assisting the diagnosis and monitoring of COVID-19 progression: An adjuvant approach for augmenting the antiviral response and mitigating the immune-mediated target organ damage

Coronavirus disease 2019 (COVID-19), which is a respiratory illness associated with high mortality, has been classified as a pandemic. The major obstacles for the clinicians to contain the disease are limited information availability, difficulty in disease diagnosis, predicting disease prognosis, and lack of disease monitoring tools. Additionally, the lack of valid therapies has further contributed to the difficulties in containing the pandemic. Recent studies have reported that the dysregulation of the immune system leads to an ineffective antiviral response and promotes pathological immune response, which manifests as ARDS, myocarditis, and hepatitis. In this study, a novel platform has been described for disseminating information to physicians for the diagnosis and monitoring of patients with COVID-19. An adjuvant approach using compounds that can potentiate antiviral immune response and mitigate COVID-19-induced immune-mediated target organ damage has been presented. A prolonged beneficial effect is achieved by implementing algorithm-based individualized variability measures in the treatment regimen.

Preclinical development of a bispecific TNFα/IL-23 neutralising domain antibody as a novel oral treatment for inflammatory bowel disease

Anti-TNFα and anti-IL-23 antibodies are highly effective therapies for Crohn’s disease or ulcerative colitis in a proportion of patients. V56B2 is a novel bispecific domain antibody in which a llama-derived IL-23p19-specific domain antibody, humanised and engineered for intestinal protease resistance, V900, was combined with a previously-described TNFα-specific domain antibody, V565. V56B2 contains a central protease-labile linker to create a single molecule for oral administration. Incubation of V56B2 with trypsin or human faecal supernatant resulted in a complete separation of the V565 and V900 monomers without loss of neutralising potency. Following oral administration of V900 and V565 in mice, high levels of each domain antibody were detected in the faeces, demonstrating stability in the intestinal milieu. In ex vivo cultures of colonic biopsies from IBD patients, treatment with V565 or V900 inhibited tissue phosphoprotein levels and with a combination of the two, inhibition was even greater. These results support further development of V56B2 as an oral therapy for IBD with improved safety and efficacy in a greater proportion of patients as well as greater convenience for patients compared with traditional monoclonal antibody therapies.

Antiviral strategies targeting host factors and mechanisms obliging +ssRNA viral pathogens

The ongoing COVID-19 pandemic, periodic recurrence of viral infections, and the emergence of challenging variants has created an urgent need of alternative therapeutic approaches to combat the spread of viral infections, failing to which may pose a greater risk to mankind in future. Resilience against antiviral drugs or fast evolutionary rate of viruses is stressing the scientific community to identify new therapeutic approaches for timely control of disease. Host metabolic pathways are exquisite reservoir of energy to viruses and contribute a diverse array of functions for successful replication and pathogenesis of virus. Targeting the host factors rather than viral enzymes to cease viral infection, has emerged as an alternative antiviral strategy. This approach offers advantage in terms of increased threshold to viral resistance and can provide broad-spectrum antiviral action against different viruses. The article here provides substantial review of literature illuminating the host factors and molecular mechanisms involved in innate/adaptive responses to viral infection, hijacking of signalling pathways by viruses and the intracellular metabolic pathways required for viral replication. Host-targeted drugs acting on the pathways usurped by viruses are also addressed in this study. Host-directed antiviral therapeutics might prove to be a rewarding approach in controlling the unprecedented spread of viral infection, however the probability of cellular side effects or cytotoxicity on host cell should not be ignored at the time of clinical investigations.

Inhalation monoclonal antibody therapy: a new way to treat and manage respiratory infections

The route of administration of a therapeutic agent has a substantial impact on its success. Therapeutic antibodies are usually administered systemically, either directly by intravenous route, or indirectly by intramuscular or subcutaneous injection. However, treatment of diseases contained within a specific tissue necessitates a better alternate route of administration for targeting localised infections. Inhalation is a promising non-invasive strategy for antibody delivery to treat respiratory maladies because it provides higher concentrations of antibody in the respiratory airways overcoming the constraints of entry through systemic circulation and uncertainity in the amount reaching the target tissue. The nasal drug delivery route is one of the extensively researched modes of administration, and nasal sprays for molecular drugs are deemed successful and are presently commercially marketed. This review highlights the current state and future prospects of inhaled therapies, with an emphasis on the use of monoclonal antibodies for the treatment of respiratory infections, as well as an overview of their importance, practical challenges, and clinical trial outcomes.Key points• Immunologic strategies for preventing mucosal transmission of respiratory pathogens.• Mucosal-mediated immunoprophylaxis could play a major role in COVID-19 prevention.• Applications of monoclonal antibodies in passive immunisation.

Inflammatory processes in the liver: divergent roles in homeostasis and pathology

The hepatic immune system is designed to tolerate diverse harmless foreign moieties to maintain homeostasis in the healthy liver. Constant priming and regulation ensure that appropriate immune activation occurs when challenged by pathogens and tissue damage. Failure to accurately discriminate, regulate, or effectively resolve inflammation offsets this balance, jeopardizing overall tissue health resulting from an either  overly tolerant or an overactive inflammatory response. Compelling scientific and clinical evidence links dysregulated hepatic immune and inflammatory responses upon sterile injury to several pathological conditions in the liver, particularly nonalcoholic steatohepatitis and ischemia-reperfusion injury. Murine and human studies have described interactions between diverse immune repertoires and nonhematopoietic cell populations in both physiological and pathological activities in the liver, although the molecular mechanisms driving these associations are not clearly understood. Here, we review the dynamic roles of inflammatory mediators in responses to sterile injury in the context of homeostasis and disease, the clinical implications of dysregulated hepatic immune activity and therapeutic developments to regulate liver-specific immunity.

Effects of compaction and storage conditions on stability of intravenous immunoglobulin - Implication on developing oral tablets of biologics

Biological products, such as therapeutic proteins, vaccines and cell - based therapeutics have a rapidly growing global market. Monoclonal antibody represents a major portion of the biologics market. For biologics that target gastrointestinal tract, the oral delivery route offers many advantages, such as better patient compliance, easy administration and increased stability, over the parental route of administration. To lay the ground work for the oral delivery of biologics, we studied the solid state properties and effects of compaction pressure, particle size, and storage relative humidity on the stability of immunoglobulin G (IVIG). We employed complementary analytical and biophysical techniques, such as size exclusion chromatography and Dynamic light scattering to characterize the aggregates, circular dichroism and solid state Fourier-transform infrared spectroscopy to evaluate protein secondary structure and nano-DSC to probe thermal stability of protein conformations. Our results showed storage relative humidity could induce conformational changes and aggregation of IVIG. However, the IVIG binding activity did not significantly change with relative humidity. The commonly used compaction pressures did not promote protein aggregation, but noticeably reduced binding activity.

Delivery of Orally Administered Digestible Antibodies Using Nanoparticles

Oral administration of medications is highly preferred in healthcare owing to its simplicity and convenience; however, problems of drug membrane permeability can arise with any administration method in drug discovery and development. In particular, commonly used monoclonal antibody (mAb) drugs are directly injected through intravenous or subcutaneous routes across physical barriers such as the cell membrane, including the epithelium and endothelium. However, intravenous administration has disadvantages such as pain, discomfort, and stress. Oral administration is an ideal route for mAbs. Nonetheless, proteolysis and denaturation, in addition to membrane impermeability, pose serious challenges in delivering peroral mAbs to the systemic circulation, biologically, through enzymatic and acidic blocks and, physically, through the small intestinal epithelium barrier. A number of clinical trials have been performed using oral mAbs for the local treatment of gastrointestinal diseases, some of which have adopted capsules or tablets as formulations. Surprisingly, no oral mAbs have been approved clinically. An enteric nanodelivery system can protect cargos from proteolysis and denaturation. Moreover, mAb cargos released in the small intestine may be delivered to the systemic circulation across the intestinal epithelium through receptor-mediated transcytosis. Oral Abs in milk are transported by neonatal Fc receptors to the systemic circulation in neonates. Thus, well-designed approaches can establish oral mAb delivery. In this review, I will introduce the implementation and possibility of delivering orally administered mAbs with or without nanoparticles not only to the local gastrointestinal tract but also to the systemic circulation.

Inflammatory Mechanisms Underlying Nonalcoholic Steatohepatitis and the Transition to Hepatocellular Carcinoma

Nonalcoholic fatty liver disease (NAFLD) is a rising chronic liver disease and comprises a spectrum from simple steatosis to nonalcoholic steatohepatitis (NASH) to end-stage cirrhosis and risk of hepatocellular carcinoma (HCC). The pathogenesis of NAFLD is multifactorial, but inflammation is considered the key element of disease progression. The liver harbors an abundance of resident immune cells, that in concert with recruited immune cells, orchestrate steatohepatitis. While inflammatory processes drive fibrosis and disease progression in NASH, fueling the ground for HCC development, immunity also exerts antitumor activities. Furthermore, immunotherapy is a promising new treatment of HCC, warranting a more detailed understanding of inflammatory mechanisms underlying the progression of NASH and transition to HCC. Novel methodologies such as single-cell sequencing, genetic fate mapping, and intravital microscopy have unraveled complex mechanisms behind immune-mediated liver injury. In this review, we highlight some of the emerging paradigms, including macrophage heterogeneity, contributions of nonclassical immune cells, the role of the adaptive immune system, interorgan crosstalk with adipose tissue and gut microbiota. Furthermore, we summarize recent advances in preclinical and clinical studies aimed at modulating the inflammatory cascade and discuss how these novel therapeutic avenues may help in preventing or combating NAFLD-associated HCC.

CD4 derived double negative T cells prevent the development and progression of nonalcoholic steatohepatitis

Hepatic inflammation is the driving force for the development and progression of NASH. Treatment targeting inflammation is believed to be beneficial. In this study, adoptive transfer of CD4+ T cells converted double negative T cells (cDNT) protects mice from diet-induced liver fat accumulation, lobular inflammation and focal necrosis. cDNT selectively suppress liver-infiltrating Th17 cells and proinflammatory M1 macrophages. IL-10 secreted by M2 macrophages decreases the survival and function of cDNT to protect M2 macrophages from cDNT-mediated lysis. NKG2A, a cell inhibitory molecule, contributes to IL-10 induced apoptosis and dampened suppressive function of cDNT. In conclusion, ex vivo-generated cDNT exert potent protection in diet induced obesity, type 2 diabetes and NASH. The improvement of outcome is due to the inhibition on liver inflammatory cells. This study supports the concept and the feasibility of potentially utilizing this autologous immune cell-based therapy for the treatment of NASH.

The Therapeutic Potential of Regulatory T Cells: Challenges and Opportunities

Regulatory T cells (Tregs) are an immunosuppressive subgroup of CD4+ T cells which are identified by the expression of forkhead box protein P3 (Foxp3). The modulation capacity of these immune cells holds an important role in both transplantation and the development of autoimmune diseases. These cells are the main mediators of self-tolerance and are essential for avoiding excessive immune reactions. Tregs play a key role in the induction of peripheral tolerance that can prevent autoimmunity, by protecting self-reactive lymphocytes from the immune reaction. In contrast to autoimmune responses, tumor cells exploit Tregs in order to prevent immune cell recognition and anti-tumor immune response during the carcinogenesis process. Recently, numerous studies have focused on unraveling the biological functions and principles of Tregs and their primary suppressive mechanisms. Due to the promising and outstanding results, Tregs have been widely investigated as an alternative tool in preventing graft rejection and treating autoimmune diseases. On the other hand, targeting Tregs for the purpose of improving cancer immunotherapy is being intensively evaluated as a desirable and effective method. The purpose of this review is to point out the characteristic function and therapeutic potential of Tregs in regulatory immune mechanisms in transplantation tolerance, autoimmune diseases, cancer therapy, and also to discuss that how the manipulation of these mechanisms may increase the therapeutic options.

The Current Landscape of Novel Formulations and the Role of Mathematical Modeling in Their Development

Drug delivery is an integral part of the drug development process, influencing safety and efficacy of active pharmaceutical ingredients. The application of nanotechnology has enabled the discovery of novel formulations for numerous therapeutic purposes across multiple disease areas. However, evaluation of novel formulations in clinical scenarios is slow and hampered due to various ethical and logistical barriers. Computational models have the ability to integrate existing domain knowledge and mathematical correlations, to rationalize the feasibility of using novel formulations for safely enhancing drug delivery, identifying suitable candidates, and reducing the burden on preclinical and clinical studies. In this review, types of novel formulations and their application through several routes of administration and the use of modeling approaches that can find application in different stages of the novel formulation development process are discussed.

Phenotypic Changes in Macrophage Activation in a Model of Nonalcoholic Fatty Liver Disease using Microminipigs

Aim: Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders associated with metabolic syndrome, and its prevalence has been on the rise. The pathogenesis of NAFLD has not yet been sufficiently elucidated due to the multifactorial nature of the disease, although the activation of macrophages/Kupffer cells is considered to be involved. We previously reported an animal model of NAFLD using Microminipigs ^TM (µMPs) fed high-fat diets containing cholesterol with or without cholic acid. The aim of this study was to investigate the phenotypic changes of macrophages that occur during the development of NAFLD.

Methods: Immunohistochemistry of macrophages, lymphocytes, and stellate cells was performed using liver samples, and the density of positive cells was analyzed.

Results: The number of Iba-1-positive macrophages increased with increasing cholesterol content in the diet. The numbers of CD163-positive macrophages and CD204-positive macrophages also increased with increasing cholesterol content in the diet; however, the proportion of CD204-positive macrophages among Iba-1-positive macrophages was significantly reduced by cholic acid supplementation.

Conclusion: The results suggest that lipid accumulation induced macrophage recruitment in swine livers, and that the number of M2-like macrophages increased at the early stage of NAFLD, while the number of M1-like macrophages increased at the late stage of NAFLD, resulting in a liver condition like non-alcoholic steatohepatitis. We provide evidence of the phenotypic changes that occur in macrophages during the development of NAFLD that has never been reported before using µMPs.

Adaptive immunity: an emerging player in the progression of NAFLD

In the past decade, nonalcoholic fatty liver disease (NAFLD) has become a leading cause of chronic liver disease and cirrhosis, as well as an important risk factor for hepatocellular carcinoma (HCC). NAFLD encompasses a spectrum of liver lesions, including simple steatosis, steatohepatitis and fibrosis. Although steatosis is often harmless, the lobular inflammation that characterizes nonalcoholic steatohepatitis (NASH) is considered a driving force in the progression of NAFLD. The current view is that innate immune mechanisms represent a key element in supporting hepatic inflammation in NASH. However, increasing evidence points to the role of adaptive immunity as an additional factor promoting liver inflammation. This Review discusses data regarding the role of B cells and T cells in sustaining the progression of NASH to fibrosis and HCC, along with the findings that antigens originating from oxidative stress act as a trigger for immune responses. We also highlight the mechanisms affecting liver immune tolerance in the setting of steatohepatitis that favour lymphocyte activation. Finally, we analyse emerging evidence concerning the possible application of immune modulating treatments in NASH therapy.

Limited expression of TLR9 on T cells and its functional consequences in patients with nonalcoholic fatty liver disease

Background/Aims

Toll-like receptors (TLRs) modulate T cell responses in diverse diseases. Co-stimulation of T cell activation via TLR9 induces production of interferon gamma (IFN-γ), priming of which is critical for differentiation of pro-inflammatory macrophages. These macrophages have a crucial role in nonalcoholic fatty liver disease (NAFLD). We aimed to evaluate the expression of TLR9 protein on T cells and the consequences of TLR9-mediated triggering of these cells in patients with NAFLD.

Methods

Our study included 34 patients with simple steatosis, 34 patients with nonalcoholic steatohepatitis, eight patients with NAFLD who met general diagnostic criteria but lacked histological diagnosis, and 51 control subjects. We used a synthetic TLR9 ligand to co-stimulate T cells. We measured TLR9 expression in liver and peripheral T cells and CD69 and IFN-γ as phenotypic markers of T cell activation and differentiation by flow cytometry.

Results

TLR9 expression on liver and peripheral T cells was lowest in patients with simple steatosis and was positively associated with anthropometric, biochemical, and histopathological features of NAFLD. In vitro co-stimulation of T cells from patients with simple steatosis induced a limited number of IFN-γ-producing CD8⁺ T cells. At baseline, these patients showed a low frequency of circulating type 1 CD8⁺ cells.

Conclusions

The positive associations between TLR9 and anthropometric, clinical, and histological features and the crucial role of IFN-γ-in NAFLD suggest that limited TLR9 expression and production of IFN-γ play a protective role in patients with simple steatosis.

γδ T Cell-Secreted XCL1 Mediates Anti-CD3-Induced Oral Tolerance

Oral tolerance is defined as the specific suppression of cellular and/or humoral immune responses to an Ag by prior administration of the Ag through the oral route. Although the investigation of oral tolerance has classically involved Ag feeding, we have found that oral administration of anti-CD3 mAb induced tolerance through regulatory T (Treg) cell generation. However, the mechanisms underlying this effect remain unknown. In this study, we show that conventional but not plasmacytoid dendritic cells (DCs) are required for anti-CD3-induced oral tolerance. Moreover, oral anti-CD3 promotes XCL1 secretion by small intestine lamina propria γδ T cells that, in turn, induces tolerogenic XCR1⁺ DC migration to the mesenteric lymph node, where Treg cells are induced and oral tolerance is established. Consistent with this, TCRδ^-/- mice did not develop oral tolerance upon oral administration of anti-CD3. However, XCL1 was not required for oral tolerance induced by fed Ags, indicating that a different mechanism underlies this effect. Accordingly, oral administration of anti-CD3 enhanced oral tolerance induced by fed MOG_35-55 peptide, resulting in less severe experimental autoimmune encephalomyelitis, which was associated with decreased inflammatory immune cell infiltration in the CNS and increased Treg cells in the spleen. Thus, Treg cell induction by oral anti-CD3 is a consequence of the cross-talk between γδ T cells and tolerogenic DCs in the gut. Furthermore, anti-CD3 may serve as an adjuvant to enhance oral tolerance to fed Ags.

Workup and Management of Immune-Mediated Hepatobiliary Pancreatic Toxicities That Develop During Immune Checkpoint Inhibitor Treatment

Immune checkpoint inhibitor treatment has been approved by the U.S. Food and Drug Administration for the treatment of a wide range of cancer types, including hepatocellular carcinoma. Workup and management of immune-mediated hepatitis, pancreatitis, or cholangitis that develops during immune checkpoint inhibitor treatment can be challenging. Immune-mediated hepatitis can be particularly challenging if patients have underlying viral hepatitis or autoimmune hepatitis. Patients with positive hepatitis B virus DNA should be referred to a hepatologist for antiviral therapy prior to immune checkpoint inhibitor treatment. With untreated hepatitis C virus (HCV) and elevated liver enzymes, a liver biopsy should be obtained to differentiate between HCV infection and immune-mediated hepatitis due to anti-programmed cell death protein 1 (PD-1) therapy. If autoimmune serologies are negative, then this supports a case of immune-mediated hepatitis secondary to anti-PD-1 therapy, rather than autoimmune hepatitis. In this case, an empiric steroid therapy is reasonable; however, if the patient does not respond to steroid therapy in 3-5 days, then liver biopsy should be pursued. The incidence of immune checkpoint-induced pancreatitis is low, but when it does occur, diagnosis is not straightforward. Although routine monitoring of pancreatic enzymes is not generally recommended, when pancreatitis is suspected, serum levels of amylase and lipase should be checked. Once confirmed, a steroid or other immunosuppressant (if steroids are contraindicated) should be administered along with close monitoring, and a slow tapering dosage once the pancreatitis is under control. Patients should then be monitored for recurrent pancreatitis. Finally, immune therapy-related cholangitis involves elevated bilirubin and alkaline phosphatase and, once diagnosed, is managed in the same way as immune-mediated hepatitis. KEY POINTS: Immune-mediated hepatitis, pancreatitis, and cholangitis are found in patients receiving or who have previously received immune checkpoint inhibitors. To work up immune-mediated hepatitis, viral, and autoimmune serologies, liver imaging will help to differentiate immune-mediated hepatitis from hepatitis of other etiology. Hepatology consult may be considered in patients with a history of chronic liver disease who developed hepatitis during immune checkpoint inhibitor treatment. Liver biopsy should be considered to clarify the diagnosis for case in which the hepatitis is refractory to steroid or immunosuppressant treatment. Immune-mediated pancreatitis is treated with steroid or other immunosuppressant with a slow tapering and should be monitored for recurrence.

Immune rebalancing by oral immunotherapy: A novel method for getting the immune system back on track

Immune modulating treatments are often associated with immune suppression or an opposing anti-inflammatory paradigm. As such, there is a risk of exposing patients to infections and malignancies. Contrarily, eliciting only mild immune modulation can be insufficient for alleviating immune-mediated damage. Oral immunotherapy is a novel approach that uses the inherent ability of the gut immune system to generate signals that specifically suppress inflammation at affected sites, without inducing generalized immune suppression. Oral immunotherapy is being developed as a method to rebalance systemic immunity and restore balance, getting it back on track, rather than pushing the immune response too much or too little in opposing directions. Here, I review recent preclinical and clinical data examining the technique and describe its primary advantages.