scholarly journals OP0307 A NOVEL TARGETED APPROACH TO ACHIEVE IMMUNE SYSTEM RESET: CD45-TARGETED ANTIBODY DRUG CONJUGATES AMELIORATE DISEASE IN PRECLINICAL AUTOIMMUNE DISEASE MODELS AND ENABLE AUTO-HSCT

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 190-191
Author(s):  
G. Gillard ◽  
J. Proctor ◽  
S. Hyzy ◽  
O. Mikse ◽  
T. Lamothe ◽  
...  

Background:Resetting the immune system through autologous hematopoietic stem cell transplant (autoHSCT) is a highly effective treatment in selected patients with autoimmune diseases. AutoHSCT can induce long-term remission with 80% progression free survival in multiple sclerosis patients (Muraro 2017, Burt 2019). Use of autoHSCT in scleroderma patients has achieved superior outcomes in two randomized studies compared to standard of care (Tyndall 2014, Sullivan 2018). These impressive results are achieved by a combination of the eradication of autoreactive immune effector cells and re-establishment of self-tolerance, i.e., immune system reset. However, only a small fraction of eligible patients undergo autoHSCT, largely due to toxicity associated with current conditioning protocols.Objectives:As part of our goal to enable more patients to benefit from immune system reset, we have generated novel anti-human CD45 ADCs that cross react with nonhuman primates (NHP) and an anti-mouse CD45 ADC to model the approach in mouse models of AID.Methods:The human-targeted CD45-ADC is an affinity-matured mAb that targets an epitope present on all human CD45 isoforms, is cross-reactive with NHP CD45, and is conjugated to a payload that efficiently kills both quiescent and cycling cells. This ADC is engineered to eliminate Fc-mediated effector function, enable site-specific conjugation of linker/payload, and enable rapid clearance. This ADC was evaluated in vitro and in vivo in hNSG and NHPs. The murine tool ADC specifically targets the CD45.2 isoform of mouse CD45, and is also engineered to eliminate effector function, allow for site-specific conjugation of linker payload, and be rapidly cleared. The payload for this murine tool ADC is potent and preferentially kills dividing cells. This ADC was tested for the ability to enable immune reset and ameliorate autoimmune disease in multiple disease models.Results:The anti-human CD45-ADC showed efficient killing of human HSCs and human and cyno PBMC, including CD3+cells from healthy donors and patients with MS. In hNSG, single doses of the CD45-ADC were well-tolerated and led to substantial depletion of human cells. In NHPs, single doses of CD45-ADC were well tolerated and depleted both peripheral lymphocytes and HSCs. Administration of a single dose of anti-human CD45-ADC to hNSGs with sclerodermatous xenoGVHD resulted in depletion of human T cells and resolution of symptoms. A single-dose of the anti-mouse CD45-ADC enabled full myeloablation and complete durable donor chimerism with congenic HSCT at 16 weeks. In a murine immunization model of MS, MOG-induced EAE, a single dose of the CD45-ADC followed by congenic HSCT prior to disease onset enabled full donor chimerism, significantly delayed disease onset and reduced disease severity. We are generating additional data in an adoptive transfer model of EAE to confirm and extend these results. In a murine model of arthritis, therapeutic treatment with a single dose of the CD45-ADC followed by congenic HSCT enabled complete donor chimerism and halted disease progression, comparable to with the effects of an anti-TNFα antibody. The ADC is being further evaluated in a model of type 1 diabetes and those data will be presented. These data demonstrate that CD45-ADC conditioning followed by congenic HSCT is sufficient for full myeloablation and immune reset.Conclusion:These results demonstrate that targeted immune depletion with a single dose of CD45-ADC can enable auto-HSCT and immune reset in multiple AID indications without toxic side effects. Targeted conditioning with CD45-ADC may represent a better tolerated approach for removing disease-causing cells as part of immune reset through auto-HSCT and enable more patients to benefit.Disclosure of Interests:Geoffrey Gillard Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Jennifer Proctor Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Sharon Hyzy Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Oliver Mikse Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Tahirih Lamothe Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Sean McDonough Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Nicholas Clark Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Rahul Palchaudhuri Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Anjali Bhat Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Melissa Brooks Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Ganapathy Sarma Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Prashant Bhattarai Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Pranoti Sawant Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Brad Pearse Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Charlotte McDonagh Shareholder of: Magenta Therapeutics, Employee of: Magenta Therapeutics, Tony Boitano Shareholder of: Magenta, Employee of: Magenta, Michael Cooke Shareholder of: Magenta, Employee of: Magenta

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Karli R. Reiding ◽  
Yu-Hsien Lin ◽  
Floris P. J. van Alphen ◽  
Alexander B. Meijer ◽  
Albert J. R. Heck

AbstractWhile neutrophils are critical first-responders of the immune system, they also cause tissue damage and act in a variety of autoimmune diseases. Many neutrophil proteins are N-glycosylated, a post-translational modification that may affect, among others, enzymatic activity, receptor interaction, and protein backbone accessibility. So far, a handful neutrophil proteins were reported to be decorated with atypical small glycans (paucimannose and smaller) and phosphomannosylated glycans. To elucidate the occurrence of these atypical glycoforms across the neutrophil proteome, we performed LC-MS/MS-based (glyco)proteomics of pooled neutrophils from healthy donors, obtaining site-specific N-glycan characterisation of >200 glycoproteins. We found that glycoproteins that are typically membrane-bound to be mostly decorated with high-mannose/complex N-glycans, while secreted proteins mainly harboured complex N-glycans. In contrast, proteins inferred to originate from azurophilic granules carried distinct and abundant paucimannosylation, asymmetric/hybrid glycans, and glycan phosphomannosylation. As these same proteins are often autoantigenic, uncovering their atypical glycosylation characteristics is an important step towards understanding autoimmune disease and improving treatment.


Author(s):  
Caterina Ledda ◽  
Claudia Lombardo ◽  
Elisabetta A. Tendi ◽  
Maria Hagnas ◽  
Gianluca Paravizzini ◽  
...  

: Fluoro-edenite (FE) is an asbestos-like amphibole present in the bentonitic lavas extracted from a stone quarry in Biancavilla, a village sited in the Etnean Volcanic Area (Italy). : Thoracic pathologies are the results of excessive inflammatory processes that are the early response of the immune system to inhaled fibers. As demonstrated for asbestos, fibers may trigger immune system cells in an acute and/or chronic manner. This review aims to clarify the pathways of inflammation in workers exposed to FE fibers. : Based on the articles reviewed, it seems that a permanent stimulus created by repeatedly inhaling the FE fibers and their persistence in the body can act as trigger both in promoting inflammatory processes and in immunological induction of autoimmune disease.


Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 885
Author(s):  
Georgia Fousteri ◽  
Amy Dave Jhatakia

Viral infections are a natural part of our existence. They can affect us in many ways that are the result of the interaction between the viral pathogen and our immune system. Most times, the resulting immune response is beneficial for the host. The pathogen is cleared, thus protecting our vital organs with no other consequences. Conversely, the reaction of our immune system against the pathogen can cause organ damage (immunopathology) or lead to autoimmune disease. To date, there are several mechanisms for virus-induced autoimmune disease, including molecular mimicry and bystander activation, in support of the “fertile field” hypothesis (terms defined in our review). In contrast, viral infections have been associated with protection from autoimmunity through mechanisms that include Treg invigoration and immune deviation, in support of the “hygiene hypothesis”, also defined here. Infection with lymphocytic choriomeningitis virus (LCMV) is one of the prototypes showing that the interaction of our immune system with viruses can either accelerate or prevent autoimmunity. Studies using mouse models of LCMV have helped conceive and establish several concepts that we now know and use to explain how viruses can lead to autoimmune activation or induce tolerance. Some of the most important mechanisms established during the course of LCMV infection are described in this short review.


1996 ◽  
Vol 10 (1) ◽  
pp. 57-61 ◽  
Author(s):  
J.W. Sleasman

There is a paradoxical relationship between immunodeficiency diseases and autoimmunity. While not all individuals with immunodeficiency develop autoimmunity, nor are all individuals with autoimmunity immunodeficient, defects within certain components of the immune system carry a high risk for the development of autoimmune disease. Inherited deficiencies of the complement system have a high incidence of systemic lupus erythematosus (SLE), glomerulonephritis, and vasculitis. Carrier mothers of children with chronic granulomatous disease, an X-linked defect of phagocytosis, often develop discoid lupus. Several antibody deficiencies are associated with autoimmune disease. Autoimmune cytopenias are commonly observed in individuals with selective IgA deficiency and common variable immune deficiency. Polyarticular arthritis can be seen in children with X-linked agammaglobulinemia. Combined cellular and antibody deficiencies, such as Wiskott-Aldrich syndrome, carry an increased risk for juvenile rheumatoid arthritis and autoimmune hemolytic anemia. Several hypothetical mechanisms have been proposed to explain the associations between autoimmunity and immunodeficiency. Immunologic defects may result in a failure to exclude microbial antigens, resulting in chronic immunologic activation and autoimmune symptoms. There may be shared genetic factors, such as common HLA alleles, which predispose an individual to both autoimmunity and immunodeficiency. Defects within one component of the immune system may alter the way a pathogen induces an immune response and lead to an inflammatory response directed at self-antigens. An understanding of the immunologic defects that contribute to the development of autoimmunity will provide an insight into the pathogenesis of the autoimmune process.


Author(s):  
Maria Gazouli ◽  
Leonardo Sechi ◽  
Daniela Paccagnini ◽  
Stefano Sotgiu ◽  
Giannina Arru ◽  
...  

Background:Multiple sclerosis (MS) is believed to be an autoimmune disease occurring in genetically predisposed individuals after an appropriate environmental exposure such as viral infections. Recent studies suggest a significant association between MS and the functional 5’-(GT)n polymorphism in the promoter region of the NRAMP1 gene. In the present study we aimed to evaluate the contribution of the allelic variation in the NRAMP1 promoter to MS susceptibility and to study the role of viral infection in relation to specific NRAMP1 genotypes, in a Sardinian cohort.Methods:Sixty MS patients and 66 healthy individuals were genotyped, and screened for the presence of Epstein-bar virus (EBV) and JC virus (JCV) sequences.Results:Consistent with previous autoimmune disease studies, allele 3 at the functional 5’(GT)n promoter region repeat polymorphism, was significantly overrepresented among MS patients when compared to controls (p=0.02). The EBV and JCV sequences were detected in 8/60 (13.33%) and in 4/60 (6.66%) of MS patients respectively and in 5/66 (7.57%) and in 0/66 of controls.Conclusion:The allelic variation in the NRAMP1 promoter may contribute to MS susceptibility in the Sardinian population. The viral sequences were not confined to a specific NRAMP1 genotype.


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