Eosinophil Knockout Humans: Uncovering the Role of Eosinophils Through Eosinophil-Directed Biological Therapies.

The enigmatic eosinophil has emerged as an exciting component of the immune system, involved in a plethora of homeostatic and inflammatory responses. Substantial progress has been achieved through experimental systems manipulating eosinophils in vivo, initially in mice and more recently in humans. Researchers using eosinophil knockout mice have identified a contributory role for eosinophils in basal and inflammatory processes and protective immunity. Primarily fueled by the purported proinflammatory role of eosinophils in eosinophil-associated diseases, a series of anti-eosinophil therapeutics have emerged as a new class of drugs. These agents, which dramatically deplete eosinophils, provide a valuable opportunity to characterize the consequences of eosinophil knockout humans. Herein, we comparatively describe mouse and human eosinophil knockouts. We put forth the view that human eosinophils negatively contribute to a variety of diseases and, unlike mouse eosinophils, do not yet have an identified role in physiological health; thus, clarifying all roles of eosinophils remains an ongoing pursuit.

30 Years of Biotherapeutics Development-What Have We Learned?

Since the birth of biotechnology, hundreds of biotherapeutics have been developed and approved by the US Food and Drug Administration (FDA) for human use. These novel medicines not only bring significant benefit to patients but also represent precision tools to interrogate human disease biology. Accordingly, much has been learned from the successes and failures of hundreds of high-quality clinical trials. In this review, we discuss general and broadly applicable themes that have emerged from this collective experience. We base our discussion on insights gained from exploring some of the most important target classes, including interleukin-1 (IL-1), tumor necrosis factor α (TNF-α), IL-6, IL-12/23, IL-17, IL-4/13, IL-5, immunoglobulin E (IgE), integrins and B cells. We also describe current challenges and speculate about how emerging technological capabilities may enable the discovery and development of the next generation of biotherapeutics.

Microglia Function in the Central Nervous System During Health and Neurodegeneration.

Microglia are resident cells of the brain that regulate brain development, maintenance of neuronal networks, and injury repair. Microglia serve as brain macrophages but are distinct from other tissue macrophages owing to their unique homeostatic phenotype and tight regulation by the central nervous system (CNS) microenvironment. They are responsible for the elimination of microbes, dead cells, redundant synapses, protein aggregates, and other particulate and soluble antigens that may endanger the CNS. Furthermore, as the primary source of proinflammatory cytokines, microglia are pivotal mediators of neuroinflammation and can induce or modulate a broad spectrum of cellular responses. Alterations in microglia functionality are implicated in brain development and aging, as well as in neurodegeneration. Recent observations about microglia ontogeny combined with extensive gene expression profiling and novel tools to study microglia biology have allowed us to characterize the spectrum of microglial phenotypes during development, homeostasis, and disease. In this article, we review recent advances in our understanding of the biology of microglia, their contribution to homeostasis, and their involvement in neurodegeneration. Moreover, we highlight the complexity of targeting microglia for therapeutic intervention in neurodegenerative diseases.

The basic immunology of asthma.

In many asthmatics, chronic airway inflammation is driven by IL-4-, IL-5-, and IL-13-producing Th2 cells or ILC2s. Type 2 cytokines promote hallmark features of the disease such as eosinophilia, mucus hypersecretion, bronchial hyperresponsiveness (BHR), IgE production, and susceptibility to exacerbations. However, only half the asthmatics have this "type 2-high" signature, and "type 2-low" asthma is more associated with obesity, presence of neutrophils, and unresponsiveness to corticosteroids, the mainstay asthma therapy. Here, we review the underlying immunological basis of various asthma endotypes by discussing results obtained from animal studies as well as results generated in clinical studies targeting specific immune pathways.

Microbiome and Anticancer Immunosurveillance.

Anticancer immune responses can be considered a desirable form of autoimmunity that may be profoundly shaped by the microbiome. Here, we discuss evidence for the microbiome's influence on anti-tumor immunosurveillance, including those that are indirect and can act at a distance, and we put forward hypotheses regarding mechanisms of how these effects are implemented. These may involve cross-reactivity between microbial and tumor antigens shaping T cell repertoires and/or microbial products stimulating pattern recognition receptors that influence the type and intensity of immune responses. Understanding how the microbiome impacts natural cancer immunosurveillance as well as treatment-induced immune responses will pave the way for more effective therapies and prophylactics.

New Biological Therapies for Multiple Myeloma.

Multiple myeloma is a cancer of bone marrow plasma cells that represents approximately 10% of hematologic malignancies. Though it is typically incurable, a remarkable suite of new therapies developed over the last 25 years has enabled durable disease control in most patients. This article briefly introduces the clinical features of multiple myeloma and aspects of multiple myeloma biology that modern therapies exploit. Key current and emerging treatment modalities are then reviewed, including cereblon-modulating agents, proteasome inhibitors, monoclonal antibodies, other molecularly targeted therapies (selinexor, venetoclax), chimeric antigen receptor T cells, T cell-engaging bispecific antibodies, and antibody-drug conjugates. For each modality, mechanism of action and clinical considerations are discussed. These therapies are combined and sequenced in modern treatment pathways, discussed at the conclusion of the article, which have led to substantial improvements in outcomes for multiple myeloma patients in recent years.

Reactive Astrocytes: Production, Function, and Therapeutic Potential.

Astrocytes constitute approximately 30% of the cells in the mammalian central nervous system (CNS). They are integral to brain and spinal-cord physiology and perform many functions important for normal neuronal development, synapse formation, and proper propagation of action potentials. We still know very little, however, about how these functions change in response to immune attack, chronic neurodegenerative disease, or acute trauma. In this review, we summarize recent studies that demonstrate that different initiating CNS injuries can elicit at least two types of "reactive" astrocytes with strikingly different properties, one type being helpful and the other harmful. We will also discuss new methods for purifying and investigating reactive-astrocyte functions and provide an overview of new markers for delineating these different states of reactive astrocytes. The discovery that astrocytes have different types of reactive states has important implications for the development of new therapies for CNS injury and diseases.

Dysbiosis and Associated Stool Features Improve Prediction of Response to Biological Therapy in Inflammatory Bowel Disease.

BACKGROUND & AIMS: Dysbiosis of the gut microbiota is considered a key contributor to inflammatory bowel disease (IBD) etiology. Here, we investigated potential associations between microbiota composition and the outcomes to biological therapies. METHODS: The study prospectively recruited 296 patients with active IBD (203 with Crohn's disease, 93 with ulcerative colitis) initiating biological therapy. Quantitative microbiome profiles of pretreatment and posttreatment fecal samples were obtained combining flow cytometry with 16S amplicon sequencing. Therapeutic response was assessed by endoscopy, patient-reported outcomes, and changes in fecal calprotectin. The effect of therapy on microbiome variation was evaluated using constrained ordination methods. Prediction of therapy outcome was performed using logistic regression with 5-fold cross-validation. RESULTS: At baseline, 65.9% of patients carried the dysbiotic Bacteroides2 (Bact2) enterotype, with a significantly higher prevalence among patients with ileal involvement (76.8%). Microbiome variation was associated with the choice of biological therapy rather than with therapeutic outcome. Only anti-tumor necrosis factor-α treatment resulted in a microbiome shift away from Bact2, concomitant with an increase in microbial load and butyrogen abundances and a decrease in potentially opportunistic Veillonella. Remission rates for patients hosting Bact2 at baseline were significantly higher with anti-tumor necrosis factor-α than with vedolizumab (65.1% vs 35.2%). A prediction model, based on anthropometrics and clinical data, stool features (microbial load, moisture, and calprotectin), and Bact2 detection predicted treatment outcome with 73.9% accuracy for specific biological therapies. CONCLUSION: Fecal characterization based on microbial load, moisture content, calprotectin concentration, and enterotyping may aid in the therapeutic choice of biological therapy in IBD.

Lactobacillus crispatus Limits Bladder Uropathogenic E. coli Infection by Triggering a Host Type I Interferon Response.

Many urinary tract infections (UTIs) are recurrent because uropathogens persist within the bladder epithelial cells (BECs) for extended periods between bouts of infection. Because persistent uropathogens are intracellular, they are often refractive to antibiotic treatment. The recent discovery of endogenous Lactobacillus spp. in the bladders of healthy humans raised the question of whether these endogenous bacteria directly or indirectly impact intracellular bacterial burden in the bladder. Here, we report that in contrast to healthy women, female patients experiencing recurrent UTIs have a bladder population of Lactobacilli that is markedly reduced. Exposing infected human BECs to L. crispatus in vitro markedly reduced the intracellular uropathogenic Escherichia coli (UPEC) load. The adherence of Lactobacilli to BECs was found to result in increased type I interferon (IFN) production, which in turn enhanced the expression of cathepsin D within lysosomes harboring UPECs. This lysosomal cathepsin D-mediated UPEC killing was diminished in germ-free mice and type I IFN receptor-deficient mice. Secreted metabolites of L. crispatus seemed to be responsible for the increased expression of type I IFN in human BECs. Intravesicular administration of Lactobacilli into UPEC-infected murine bladders markedly reduced their intracellular bacterial load suggesting that components of the endogenous microflora can have therapeutic effects against UTIs.

Antibody-guided proteases enable selective and catalytic degradation of challenging therapeutic targets.

The exquisite specificity, natural biological functions, and favorable development properties of antibodies make them highly effective agents as drugs. Monoclonal antibodies are particularly strong as inhibitors of systemically accessible targets where trough-level concentrations can sustain full target occupancy. Yet beyond this pharmacologic wheelhouse, antibodies perform suboptimally for targets of high abundance and those not easily accessible from circulation. Fundamentally, this restraint on broader application is due largely to the stoichiometric nature of their activity-one drug molecule is generally able to inhibit a maximum of two target molecules at a time. Enzymes in contrast are able to catalytically turnover multiple substrates, making them a natural sub-stoichiometric solution for targets of high abundance or in poorly accessible sites of action. However, enzymes have their own limitations as drugs, including, in particular, the polypharmacology and broad specificity often seen with native enzymes. In this study, we introduce antibody-guided proteolytic enzymes to enable selective sub-stoichiometric turnover of therapeutic targets. We demonstrate that antibody-mediated substrate targeting can enhance enzyme activity and specificity, with proof of concept for two challenging target proteins, amyloid-ß and immunoglobulin G. This work advances a new biotherapeutic platform that combines the favorable properties of antibodies and proteolytic enzymes to more effectively suppress high-bar therapeutic targets.

Emerging biologic therapies for systemic lupus erythematosus.

PURPOSE OF REVIEW: The approval of belimumab and anifrolumab has expanded the scope of treatment for systemic lupus erythematosus (SLE) patients. However, many patients remain refractory to currently available therapies and suffer from drug toxicities. This review will discuss approved and target-specific therapeutics in development that bring hope for better SLE treatments. RECENT FINDINGS: Since the last review on this subject in the journal, the FDA has approved anifrolumab and belimumab for SLE and lupus nephritis (LN), respectively. A fully humanized anti-CD20, obinutuzumab, met the primary end point in a phase II trial in LN. A Tyk2 inhibitor, deucravacitinib, and an antibody targeting plasmacytoid dendritic cells, litifilimab, met the primary end point in phase II trials in SLE and cutaneous lupus erythematosus (CLE). Ustekinumab and baricitinib met the primary end point in phase II but not in phase III trials. SUMMARY: While many drug candidates which met the end points in phase II trials have failed phase III trials, the number of target-specific therapies for SLE has continued to expand.

Outcome of Biological Therapies and Small Molecules in Ulcerative Proctitis: A Belgian Multicenter Cohort Study.

BACKGROUND & AIMS: Several advanced therapies (biologic therapies and small molecules) have been approved for the treatment of moderate-to-severe ulcerative colitis. The registration trials for these agents typically excluded patients with isolated proctitis, leaving an evidence gap. We evaluated efficacy and safety of advanced therapies in patients with ulcerative proctitis (UP). METHODS: This multicenter retrospective cohort study included consecutive patients with active UP (Mayo endoscopy subscore of ≥2, rectal inflammation up to 15 cm) initiating advanced therapy, after failing conventional therapy. The primary end point was short-term steroid-free clinical remission (total Mayo score ≤2 with no individual subscore >1). In addition, drug persistence and relapse-free and colectomy-free survival were assessed. Both binary logistic and Cox regression analyses were performed. RESULTS: In total, 167 consecutive patients (52.0% female; median age 41.0 years; 82.0% bionaive) underwent 223 courses of therapy for UP (38 adalimumab, 14 golimumab, 54 infliximab, 9 ustekinumab, 99 vedolizumab, 9 tofacitinib). The primary end point was achieved with 36.3% of the treatment courses, and based on multivariate analysis, more commonly attained in bionaive patients (P = .001), patients treated with vedolizumab (P = .001), patients with moderate endoscopic disease activity (P = .002), and a body mass index <25 kg/m2 (P = .018). Drug persistence was significantly higher in patients treated with vedolizumab (P < .001) and patients with a shorter disease duration (P = .006). No new safety signals were observed. CONCLUSIONS: Advanced therapies are also efficacious and safe in patients with ulcerative colitis limited to the rectum. Therefore, the inclusion of patients with UP in future randomized-controlled trials should be considered.

Comparative Effectiveness of Biologic Therapies in Preventing Penetrating Complications in Patients With Crohn's Disease.

BACKGROUND & AIMS: Comparative effectiveness of biologics in preventing penetrating disease (PD) in Crohn's disease (CD) is not well established. We compared the risk of developing luminal and perianal PD (LPD and PPD) between biologics used as first-line therapies. METHODS: Adults (>17 years) with CD who initiated their first biologic (anti-tumor necrosis factor [anti-TNF], ustekinumab [UST], or vedolizumab [VDZ]) were identified from Merative Commercial Database (2006 and 2020). We excluded preexisting PD using a minimum look-back period of 1 year. Cohorts were balanced by inverse probability of treatment weighting based on age, sex, comorbidities, prior CD surgery, and CD severity. Pairwise comparisons were performed by Cox proportional hazards models, adjusted for immunomodulator exposure, and with biologic exposure treated as a time-dependent variable based on a medication possession ratio of 0.8. RESULTS: Our analysis included 40,693 patients: 93% anti-TNF, 3% UST, and 4% VDZ. After inverse probability of treatment weighting all comparisons were well balanced. Anti-TNF was protective against LPD (hazard ratio, 0.66; 95% confidence interval, 0.55-0.78; P < .0001) and PPD (hazard ratio, 0.88; 95% confidence interval, 0.80-0.96; P = .0045) compared with VDZ and LPD (hazard ratio, 0.37; 95% confidence interval, 0.30-0.46; P < .0001) compared with UST. There were no significant differences in the risk of LPD and PPD between VDZ and UST. These results were similar after limiting the study period to after 2016. CONCLUSIONS: Anti-TNF therapy was associated with a lower risk of LPD and PPD compared with VDZ, and lower risk of LPD compared with UST. Further studies are needed to validate these findings and to determine potential reasons for these differences.

Higher Intra-Abdominal Visceral Adipose Tissue Mass Is Associated With Lower Rates of Clinical and Endoscopic Remission in Patients With Inflammatory Bowel Diseases Initiating Biologic Therapy: Results of the Constellation Study.

BACKGROUND & AIMS: We sought to assess the association between intra-abdominal visceral adipose tissue (IA-VAT) and response to 3 different biologic drugs in patients with inflammatory bowel disease (IBD) and to investigate its effects on inflammatory cytokine expression, pharmacokinetics, and intestinal microbiota. METHODS: We prospectively enrolled subjects with active IBD initiating infliximab, vedolizumab, or ustekinumab and a healthy control group. Baseline body composition (including IA-VAT as percent of total body mass [IA-VAT%]) was measured using GE iDXA scan. Primary outcome was corticosteroid- free deep remission at weeks 14-16, defined as Harvey Bradshaw Index <5 for Crohn's disease and partial Mayo score <2 for ulcerative colitis, with a normal C-reactive protein and fecal calprotectin. Secondary outcomes were corticosteroid-free deep remission and endoscopic remission (Endoscopic Mayo Score ≤1 in ulcerative colitis or Simple Endoscopic Score for Crohn's disease ≤2) at weeks 30-46. RESULTS: A total of 141 patients with IBD and 51 healthy controls were included. No differences in body composition parameters were seen between the IBD and healthy control cohorts. Patients with higher IA-VAT% were less likely to achieve corticosteroid-free deep remission (P < .001) or endoscopic remission (P = .02) vs those with lower IA-VAT%. Furthermore, nonresponders with high IA-VAT% had significantly higher serum interleukin-6 and tumor necrosis factor at baseline compared with responders and patients with low IA-VAT%. Drug pharmacokinetic properties and microbiota diversity were similar when comparing high and low IA-VAT% groups. CONCLUSIONS: Higher IA-VAT% was independently associated with worse outcomes. This association could be driven at least partially by discrete differences in inflammatory cytokine expression.

Multidimensional Applications and Challenges of Riboswitches in Biosensing and Biotherapy.

Riboswitches have received significant attention over the last two decades for their multiple functionalities and great potential for applications in various fields. This article highlights and reviews the recent advances in biosensing and biotherapy. These fields involve a wide range of applications, such as food safety detection, environmental monitoring, metabolic engineering, live cell imaging, wearable biosensors, antibacterial drug targets, and gene therapy. The discovery, origin, and optimization of riboswitches are summarized to help readers better understand their multidimensional applications. Finally, this review discusses the multidimensional challenges and development of riboswitches in order to further expand their potential for novel applications.

Advancements in NMN biotherapy and research updates in the field of digestive system diseases.

Nicotinamide mononucleotide (NMN), a crucial intermediate in NAD + synthesis, can rapidly transform into NAD + within the body after ingestion. NMN plays a pivotal role in several important biological processes, including energy metabolism, cellular aging, circadian rhythm regulation, DNA repair, chromatin remodeling, immunity, and inflammation. NMN has emerged as a key focus of research in the fields of biomedicine, health care, and food science. Recent years have witnessed extensive preclinical studies on NMN, offering valuable insights into the pathogenesis of age- and aging-related diseases. Given the sustained global research interest in NMN and the substantial market expectations for the future, here, we comprehensively review the milestones in research on NMN biotherapy over the past 10 years. Additionally, we highlight the current research on NMN in the field of digestive system diseases, identifying existing problems and challenges in the field of NMN research. The overarching aim of this review is to provide references and insights for the further exploration of NMN within the spectrum of digestive system diseases.

Ocular surface disease in moderate-to-severe atopic dermatitis patients and the effect of biological therapy.

Atopic dermatitis (AD) is a chronic inflammatory skin disease for which new targeted therapies are currently available. Due to the increased rates of ocular surface disease (OSD) reported during treatment with these new targeted treatments, more insight into the occurrence and pathomechanism of OSD in moderate-to-severe AD patients is needed. Therefore, this review's first part highlights that most patients with moderate-to-severe AD already have characteristics of OSD before starting targeted treatment. Remarkably, not all AD patients with OSD report ocular symptoms. OSD in AD is associated with less conjunctival goblet cells (GC) compared to healthy controls. In addition, OSD severity in AD patients is associated with high AD activity, the presence of eyelid and/or facial eczema, and high levels of AD-related severity biomarkers in tear fluid. The second part of this review highlights that pre-existing ocular pathology (e.g. in combination with the use of ophthalmic medication or eyelid eczema) may be associated with the development of dupilumab-associated ocular surface disease (DAOSD). During dupilumab treatment, DAOSD (which can be new-onset OSD or worsening of pre-existing OSD) is observed in approximately one-third of the dupilumab-treated AD patients. Anti-inflammatory ophthalmic treatment improves DAOSD, and dose reduction of dupilumab may also be an effective treatment option. The pathomechanism of DAOSD is still not fully elucidated. In a prospective study low, but stable conjunctival GC numbers were observed in moderate-to-severe AD patients, before and during dupilumab treatment. However, the Mucin 5 AC (MUC5AC) expression of GCs decreased during dupilumab treatment, suggesting an impairment of the GC function by dupilumab treatment. In addition, higher dupilumab tear fluid levels were found in dupilumab-treated AD patients with moderate-to-severe OSD compared to patients with no or mild OSD, whereas the dupilumab serum levels are similar. Clinicians should be aware of the frequent occurrence of OSD in moderate-to-severe AD patients, and a low-threshold referral to an ophthalmologist is recommended.

Development of human endogenous retrovirus type K- related treatments for human diseases.

Human endogenous retroviruses (HERVs) constitute approximately 8% of the human genome and have long been regarded as silent passengers within our genomes. However, the reactivation of HERVs has been increasingly linked to a range of human diseases, particularly the HERV-K (HML-2) family. Many studies are dedicated to elucidating the potential role of HERV-K in pathogenicity. While the underlying mechanisms require further investigation, targeting HERV-K transactivation emerges as a promising avenue for treating human diseases, including cancer, autoimmune disorders, neurodegenerative conditions, and infectious diseases. In this review, we summarize recent advancements in the development of HERV-K-targeted therapeutic strategies against various human diseases, including antiretroviral drugs, immunotherapy, and vaccines.

Is there a role for autologous conditioned serum injections in osteoarthritis? A systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: To assess whether patient reported outcome measures (PROMs) improve after autologous conditioned serum (ACS) administration in patients with osteoarthritis. METHODS: Databases and clinical trial registers were searched to March 2024 for randomised controlled trial (RCTs) comparing ACS vs comparators/controls. Primary outcomes were pain, function and stiffness measured with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and visual analogue scale (VAS). Secondary outcome was complications. Risk of bias (RoB) and certainty of evidence were assessed using RoB 2 and the Grades of Recommendation, Assessment, Development and Evaluation Working Group (GRADE) respectively. Meta-analysis was undertaken using RevMan v5.4. Results are presented as standardised mean differences (SMD) or mean differences (MD) with 95% confidence intervals (CI). Sensitivity analysis compared all comparators and saline control. RESULTS: Five RCTs were identified (n = 741 participants); two (n = 529 participants) compared ACS against saline (placebo). Three studies were "some concern" and two studies "high risk" for bias. Analysis comparing ACS with all comparators significantly favoured ACS at 6 months for WOMAC: SMD -0.61 (95% CI -1.01 to -0.21; p = 0.003); and VAS: SMD -1.24 (95% CI -2.11 to -0.38; p = 0.005); with high heterogeneity. Comparing ACS with saline, there was no significant difference in WOMAC or VAS at 6 months: SMD -0.40 (95% CI -0.93 to 0.12; p = 0.13) and MD -9.87 (95% CI -27.73 to 7.98, p = 0.28). Complications were similar: ACS (24.8%) vs saline (24.4%), with serious complications rare. CONCLUSION: There is currently insufficient data to support the use of ACS in osteoarthritis with conflicting results when compared to alternative therapies and saline control, with high heterogeneity. Before consideration as a potential treatment, a high-quality multicentre RCT is required to assess the efficacy of ACS.

Safety of biologic therapy in combination with methotrexate in moderate to severe psoriasis: a cohort study from the BIOBADADERM registry.

BACKGROUND: Safety is an important consideration in decisions on treatment for patients with moderate-to-severe psoriasis and the study of drug safety is the main purpose of the BIOBADADERM registry. The combination of a biologic agent and a conventional systemic drug [generally methotrexate (MTX)] is a common treatment in clinical practice. However, there is a paucity of evidence from real-world practice on the safety of such combination regimens in the treatment of psoriasis. OBJECTIVES: The primary objective of this study was to ascertain whether the use of regimens combining biologic drugs with MTX in the management of moderate-to-severe psoriasis increases the risk of adverse events (AEs) or serious AEs (SAEs). We compared monotherapy using tumour necrosis factor (TNF), interleukin (IL)-17 and IL-23 inhibitors with the use of the same drugs in combination with MTX. METHODS: Using data from the BIOBADADERM registry, we compared biologic monotherapies with therapies that were combined with MTX. We estimated adjusted incidence rate ratios (aIRR) using a random effects Poisson regression with 95% confidence intervals for all AEs, SAEs, infections and serious infections and other AEs by system organ class. RESULTS: We analysed data from 2829 patients and 5441 treatment cycles, a total of 12 853 patient-years. The combination of a biologic with MTX was not associated with statistically significant increases in overall risk of AEs or SAEs in any treatment group. No increase in the total number of infections or serious infections in patients receiving combined therapy was observed for any group. However, treatment with a TNF inhibitor combined with MTX was associated with an increase in the incidence of gastrointestinal AEs (aIRR 2.50, 95% CI 1.57-3.98; P < 0.002). CONCLUSIONS: The risk of AEs and SAEs was not significantly increased in patients with moderate-to-severe psoriasis receiving different classes of biologic drugs combined with MTX compared with those on biologic monotherapy.