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Discover how PEPperPRINT Peptide Microarray products have been used in different fields of research.

The Correlation between Subolesin-Reactive Epitopes and Vaccine Efficacy

Contreras, Marinela; Kasaija, Paul D.; Kabi, Fredrick; Mugerwa, Swidiq; De la Fuente, José
Vaccines.
Aug 2022
Vaccination is an environmentally-friendly alternative for tick control. The tick antigen Subolesin (SUB) has shown protection in vaccines for the control of multiple tick species in cattle. Additionally, recent approaches in quantum vaccinomics have predicted SUB-protective epitopes and the peptide sequences involved in protein–protein interactions in this tick antigen. Therefore, the identification of B-cell–reactive epitopes by epitope mapping using a SUB peptide array could be essential as a novel strategy for vaccine development. Subolesin can be used as a model to evaluate the effectiveness of these approaches for the identification of protective epitopes related to vaccine protection and efficacy. In this study, the mapping of B-cell linear epitopes of SUB from three different tick species common in Uganda (Rhipicephalus appendiculatus, R. decoloratus, and Amblyomma variegatum) was conducted using serum samples from two cattle breeds immunized with SUB-based vaccines. The results showed that in cattle immunized with SUB from R. appendiculatus (SUBra) all the reactive peptides (Z-score > 2) recognized by IgG were also significant (Z-ratio > 1.96) when compared to the control group. Additionally, some of the reactive peptides recognized by IgG from the control group were also recognized in SUB cocktail–immunized groups. As a significant result, cattle groups that showed the highest vaccine efficacy were Bos indicus immunized with a SUB cocktail (92%), and crossbred cattle were immunized with SUBra (90%) against R. appendiculatus ticks; the IgG from these groups recognized overlapping epitopes from the peptide SPTGLSPGLSPVRDQPLFTFRQVGLICERMMKERESQIRDEYDHVLSAKLAEQYDTFVKFTYDQKRFEGATPSYLS (Z-ratio > 1.96), which partially corresponded to a Q38 peptide and the SUB protein interaction domain. These identified epitopes could be related to the protection and efficacy of the SUB-based vaccines, and new chimeras containing these protective epitopes could be designed using this new approach.

A new mechanism of fibronectin fibril assembly revealed by live imaging and super-resolution microscopy

Tomer, Darshika; Arriagada, Cecilia; Munshi, Sudipto; Alexander, Brianna E.; French, Brenda; Vedula, Pavan; Caorsi, Valentina; House, Andrew; Guvendiren, Murat; Kashina, Anna; Schwarzbauer, Jean E.; Astrof, Sophie
ABSTRACT Fibronectin (Fn1) fibrils have long been viewed as continuous fibers composed of extended, periodically aligned Fn1 molecules. However, our live-imaging and single-molecule localization microscopy data are inconsistent with this traditional view and show that Fn1 fibrils are composed of roughly spherical nanodomains containing six to eleven Fn1 dimers. As they move toward the cell center, Fn1 nanodomains become organized into linear arrays, in which nanodomains are spaced with an average periodicity of 105±17 nm. Periodical Fn1 nanodomain arrays can be visualized between cells in culture and within tissues; they are resistant to deoxycholate treatment and retain nanodomain periodicity in the absence of cells. The nanodomain periodicity in fibrils remained constant when probed with antibodies recognizing distinct Fn1 epitopes or combinations of antibodies recognizing epitopes spanning the length of Fn1. Treatment with FUD, a peptide that binds the Fn1 N-terminus and disrupts Fn1 fibrillogenesis, blocked the organization of Fn1 nanodomains into periodical arrays. These studies establish a new paradigm of Fn1 fibrillogenesis. This article has an associated First Person interview with the first author of the paper.

A heterotypic assembly mechanism regulates CHIP E3 ligase activity

Das, Aniruddha; Thapa, Pankaj; Santiago, Ulises; Shanmugam, Nilesh; Banasiak, Katarzyna; Dąbrowska, Katarzyna; Nolte, Hendrik; Szulc, Natalia A; Gathungu, Rose M; Cysewski, Dominik; Krüger, Marcus; Dadlez, Michał; Nowotny, Marcin; Camacho, Carlos J; Hoppe, Thorsten; Pokrzywa, Wojciech
The EMBO Journal.
Aug 2022
CHIP (C‐terminus of Hsc70‐interacting protein) and its worm ortholog CHN‐1 are E3 ubiquitin ligases that link the chaperone system with the ubiquitin‐proteasome system (UPS). CHN‐1 can cooperate with UFD‐2, another E3 ligase, to accelerate ubiquitin chain formation; however, the basis for the high processivity of this E3s set has remained obscure. Here, we studied the molecular mechanism and function of the CHN‐1–UFD‐2 complex in Caenorhabditis elegans. Our data show that UFD‐2 binding promotes the cooperation between CHN‐1 and ubiquitin‐conjugating E2 enzymes by stabilizing the CHN‐1 U‐box dimer. However, HSP70/HSP‐1 chaperone outcompetes UFD‐2 for CHN‐1 binding, thereby promoting a shift to the autoinhibited CHN‐1 state by acting on a conserved residue in its U‐box domain. The interaction with UFD‐2 enables CHN‐1 to efficiently ubiquitylate and regulate S‐adenosylhomocysteinase (AHCY‐1), a key enzyme in the S‐adenosylmethionine (SAM) regeneration cycle, which is essential for SAM‐dependent methylation. Our results define the molecular mechanism underlying the synergistic cooperation of CHN‐1 and UFD‐2 in substrate ubiquitylation.

Mapping and Validation of Peptides Differentially Recognized by Antibodies from the Serum of Yellow Fever Virus-Infected or 17DD-Vaccinated Patients

Oliveira, Eneida Santos; Tavares, Naiara Clemente; Colombarolli, Stella Garcia; Batista, Izabella Cristina Andrade; Nascimento, Camila Sales; Felgner, Philip Louis; de Assis, Rafael Ramiro; Calzavara-Silva, Carlos Eduardo
Viruses.
Jul 2022
Yellow Fever disease is caused by the Yellow Fever virus (YFV), an arbovirus from the Flaviviridae family. The re-emergence of Yellow Fever (YF) was facilitated by the increasing urbanization of sylvatic areas, the wide distribution of the mosquito vector, and the low percentage of people immunized in the Americas, which caused severe outbreaks in recent years, with a high mortality rate. Therefore, serological approaches capable of discerning antibodies generated from the wild-type (YFV-WT) strain between the vaccinal strain (YFV-17DD) could facilitate vaccine coverage surveillance, enabling the development of strategies to avoid new outbreaks. In this study, peptides were designed and subjected to microarray procedures with sera collected from individuals infected by WT-YFV and 17DD–YFV of YFV during the Brazilian outbreak of YFV in 2017/2018. From 222 screened peptides, around ten could potentially integrate serological approaches aiming to differentiate vaccinated individuals from naturally infected individuals. Among those peptides, one was synthesized and validated through ELISA.

Multiplex peptide microarray profiling of antibody reactivity against neglected tropical diseases derived B-cell epitopes for serodiagnosis in Zimbabwe

Vengesai, Arthur; Naicker, Thajasvarie; Midzi, Herald; Kasambala, Maritha; Mduluza-Jokonya, Tariro L.; Rusakaniko, Simbarashe; Mutapi, Francisca; Mduluza, Takafira
PLoS ONE.
Jul 2022
Introduction Peptides (B-cell epitopes) have broad applications in disease diagnosis and surveillance of pathogen exposure. In this framework, we present a pilot study to design and produce a peptide microarray for the integrated surveillance of neglected tropical diseases. The peptide microarray was evaluated against peptides derived from Ascaris lumbricoides, Necator americanus, Schistosoma haematobium, Schistosoma mansoni, Trichuris trichiura, Bacillus anthracis, Mycobacterium leprae, Wuchereria bancrofti, Rabies lyssavirus, Chlamydia trachomatis and Trypanosoma brucei. Methods S. haematobium was diagnosed using the urine filtration technique. S. mansoni, A. lumbricoides, N. americanus and T. trichiura were diagnosed using the Kato Katz and formal ether concentration techniques. Immunogenic peptides were retrieved from the Tackling Infection to Benefit Africa infectious diseases epitope microarray. Further peptides were predicted using ABCpred. IgG and IgM reactivity against the derived peptides were evaluated using peptide microarray multiplex immunoassays. Positive response was defined as fluorescence intensity ≥ 500 fluorescence units. Immunodominant peptides were identified using color-coded heat maps and bar graphs reflecting the obtained fluorescence signal intensities. Receiver Operating Characteristic analysis and Mann-Whitney-U test were performed to determine the diagnostic validity of the peptides. Results Species-specific responses with at least one peptide derived from each NTD pathogen were observed. The reactive peptides included; for S. haematobium, XP_035588858.1-206-220 and XP_035588858.1-206-220 immunodominant for IgG and IgM respectively, for S. mansoni, P20287.1-58-72 immunodominant for both antibodies and for T. trichiura, CDW52482.1-326-340 immunodominant for IgG and CDW57769.1-2017-2031 and CDW57769.1-1518-1532 immunodominant for IgM. According to ROC analysis most of the peptides selected were inaccurate; with AUC < 0.5. Some peptides had AUC values ranging from 0.5 to 0.5875 for both IgM and IgG suggesting no discrimination. Conclusion Multiplex peptide microarrays are a valuable tool for integrated NTDs surveillance and for screening parasites exposure in endemic areas. Species sero-reactivity observed in the study maybe indicative of exposure to the different NTDs parasites. However, although peptides with the least cross reactivity were selected there is need to validate the sero-reactivity with recombinant antigens and immune-blotting techniques such as western blotting.

Structure of PLA2R reveals presentation of the dominant membranous nephropathy epitope and an immunogenic patch

Fresquet, Maryline; Lockhart-Cairns, Michael P.; Rhoden, Samuel J.; Jowitt, Thomas A.; Briggs, David C.; Baldock, Clair; Brenchley, Paul E.; Lennon, Rachel
Proc. Natl. Acad. Sci. U.S.A..
Jul 2022
Membranous nephropathy is an autoimmune kidney disease caused by autoantibodies targeting antigens present on glomerular podocytes, instigating a cascade leading to glomerular injury. The most prevalent circulating autoantibodies in membranous nephropathy are against phospholipase A2 receptor (PLA2R), a cell surface receptor. The dominant epitope in PLA2R is located within the cysteine-rich domain, yet high-resolution structure-based mapping is lacking. In this study, we define the key nonredundant amino acids in the dominant epitope of PLA2R involved in autoantibody binding. We further describe two essential regions within the dominant epitope and spacer requirements for a synthetic peptide of the epitope for drug discovery. In addition, using cryo-electron microscopy, we have determined the high-resolution structure of PLA2R to 3.4 Å resolution, which shows that the dominant epitope and key residues within the cysteine-rich domain are accessible at the cell surface. In addition, the structure of PLA2R not only suggests a different orientation of domains but also implicates a unique immunogenic signature in PLA2R responsible for inducing autoantibody formation and recognition.

Rise of the SARS-CoV-2 Variants: can proteomics be the silver bullet?

Acharjee, Arup; Stephen Kingsly, Joshua; Kamat, Madhura; Kurlawala, Vishakha; Chakraborty, Aparajita; Vyas, Priyanka; Vaishnav, Radhika; Srivastava, Sanjeeva
Expert Rev Proteomics.
Jun 2022
10.1080/14789450.2022.2085564
INTRODUCTION: The challenges posed by emergent strains of SARS-CoV-2 need to be tackled by contemporary scientific approaches, with proteomics playing a significant role. AREAS COVERED: In this review, we provide a brief synthesis of the impact of proteomics technologies in elucidating disease pathogenesis and classifiers for the prognosis of COVID-19 and propose proteomics methodologies that could play a crucial role in understanding emerging variants and their altered disease pathology. From aiding the design of novel drug candidates to facilitating the identification of T cell vaccine targets, we have discussed the impact of proteomics methods in COVID-19 research. Techniques varied as mass spectrometry, single-cell proteomics, multiplexed ELISA arrays, high-density proteome arrays, surface plasmon resonance, immunopeptidomics, and in silico docking studies that have helped augment the fight against existing diseases were useful in preparing us to tackle SARS-CoV-2 variants. We also propose an action plan for a pipeline to combat emerging pandemics using proteomics technology by adopting uniform standard operating procedures and unified data analysis paradigms. EXPERT OPINION: The knowledge about the use of diverse proteomics approaches for COVID-19 investigation will provide a framework for future basic research, better infectious disease prevention strategies, improved diagnostics, and targeted therapeutics.

Development and Optimization of Bifunctional Fusion Proteins to Locally Modulate Complement Activation in Diseased Tissue

Fahnoe, Kelly C.; Liu, Fei; Morgan, Jennifer G.; Ryan, Sarah T.; Storek, Michael; Stark, Ellen Garber; Taylor, Fred R.; Holers, V. Michael; Thurman, Joshua M.; Wawersik, Stefan; Kalled, Susan L.; Violette, Shelia M.
Front Immunol.
Jun 2022
10.3389/fimmu.2022.869725
Sustained complement activation is an underlying pathologic driver in many inflammatory and autoimmune diseases. Currently approved anti-complement therapies are directed at the systemic blockade of complement. Consequently, these therapies provide widespread inhibition of complement pathway activity, beyond the site of ongoing activation and the intended pharmacodynamic (PD) effects. Given the essential role for complement in both innate and adaptive immunity, there is a need for therapies that inhibit complement in diseased tissue while limiting systemic blockade. One potential approach focuses on the development of novel fusion proteins that enable tissue-targeted delivery of complement negative regulatory proteins. These therapies are expected to provide increased potency and prolonged tissue PD, decreased dosing frequency, and the potential for improved safety profiles. We created a library of bifunctional fusion proteins that direct a fragment of the complement negative regulator, complement receptor type 1 (CR1) to sites of tissue injury. Tissue targeting is accomplished through the binding of the fusion protein to complement C3 fragments that contain a surface-exposed C3d domain and which are covalently deposited on tissues where complement is being activated. To that end, we generated a fusion protein that contains an anti-C3d monoclonal antibody recombinantly linked to the first 10 consensus repeats of CR1 (CR11-10) with the intention of delivering high local concentrations of this complement negative regulatory domain to tissue-bound complement C3 fragments iC3b, C3dg and C3d. Biochemical and in vitro characterization identified several fusion proteins that inhibit complement while maintaining the C3d domain binding properties of the parent monoclonal antibody. Preclinical in vivo studies further demonstrate that anti-C3d fusion proteins effectively distribute to injured tissue and reduce C3 fragment deposition for periods beyond 14 days. The in vitro and in vivo profiles support the further evaluation of C3d mAb-CR11-10 as a novel approach to restore proper complement activation in diseased tissue in the absence of continuous systemic complement blockade.

IFx-Hu2.0 phase I first in human study for unresectable melanoma for an intralesional “in-situ vaccine” approach.

Markowitz, Joseph; Shamblott, Michael; Brohl, Andrew Scott; Sarnaik, Amod; Eroglu, Zeynep; Khushalani, Nikhil I.; Chen, Pei-Ling; De-Aquino, Deanryan B.; Sondak, Vernon K.; Tarhini, Ahmad A.; Kim, Youngchul; Pilon-Thomas, Shari
e21542 Background: Many melanoma patients do not respond to anti-PD1 therapy due to lack of antigen specific responses. IFx-Hu2.0 (plasmid DNA encoding the streptococcal membrane protein, Emm55, contained within a cationic polymer) primes innate and antigen dependent responses in murine/equine melanoma models to produce an environment needed for checkpoint inhibitor efficacy. We describe the first in human study utilizing IFx-Hu2.0 in unresectable melanoma – NCT03655756. Methods: Melanoma patients (unresectable stage III/IV) had cutaneous lesions injected with IFx-Hu2.0 to test safety and feasibility. Patients were refractory to standard of care (anti-PD1, BRAF/MEK) or did not wish these treatments. 1-3 lesions (> 3 mm – 0.1 mg/0.2 mL) were injected, pre/post treatment biopsies obtained, and the primary endpoint of 5/6 patients without dose limiting toxicity (DLT) was assessed at 28 days. Retreatment was permitted. ≥2 lesions were needed: one for injection and uninjected lesion for biopsy. Tissue samples were analyzed for mRNA profiles, antigen responses (PEPperPRINT assay), and multiplex immunofluorescence (markers: CD3, CD8, FOXP3, PD1, PDL1, SOX10, DAPI). Results: The primary endpoint was met in 6 evaluable patients out of 7 enrolled. Observed toxicities included: G1-2 Injection site reactions – 5/7; G1 Bleeding – 1/7; G1-2 Pain – 2/7, G1 Lymphopenia – 1/7, G1 Pruritis – 1/7; with no ≥ G3 toxicities related to study drug observed. One G5 toxicity (Clostridium septicum infection 20 days post injection) was deemed unlikely related to study drug. 5/6 patients received 1 cycle prior to post-protocol immune-based therapy. One treatment naïve patient retreated once with IFx-Hu2.0 required no additional therapy > 9 months. Available paired tissue and plasma sampling revealed increased T cell infiltration into treated lesions, increase in IgM and IgG epitope recognition to melanoma associated antigens in the plasma (detected by PEPperPRINT assay), an increase in mRNA associated with innate immune responses in the injected lesion (CXCL13, LAG3, CXCL11, CXCL10, ICOS) and an adaptive immune response (IL-12, HLA-DRB5, WNT4, CD3D, Arg I) in uninjected lesions associated with downregulation of known melanoma antigens. Of 4 anti-PD1 refractory patients, three patients had clinical benefit to post-protocol retreatment with anti-PD1 based therapy (Stable Disease (SD) lasting > 2 years followed by surgical resection, Partial Response (PR) lasting > 9 months, PR subsequently surgical resected and rendered no evidence of disease). Conclusions: In this pilot study, intralesional IFx-Hu2.0 demonstrated a favorable safety profile. These data support encouraging immunological correlative responses and further study of IFx-Hu2.0 as a priming agent to enhance or restore sensitivity to immune checkpoint inhibitor therapy in melanoma. Clinical trial information: NCT03655756.

Clonal expansion and markers of directed mutation of IGHV4-34 B cells in plasmablasts during Kawasaki disease

Chang, Arthur J.; Baron, Sarah; Hoffman, Jonathon; Hicar, Mark D.
Molecular Immunology.
May 2022
Kawasaki disease (KD) is the leading cause of acquired heart disease in children. The cause remains unknown; however, epidemiologic and demographic data support a single preceding infectious agent may lead to KD. A variety of pathophysiologic responses have been proposed, including direct invasion of the coronary arteries, a superantigen response, and a post-infectious autoimmune phenomenon. A role for B cell responses during KD are supported by numerous findings including B cell specific markers identified in genome wide association studies. We have recently published data showing children with KD have similar plasmablast (PB) responses to children with infections. Since during other infections, cells expressing antibodies against the preceding infection are enriched in PBs, we sought to explore the specific antibodies encoded by PBs during KD. In one child we see a massive expansion in IGHV4–34 utilizing antibodies, which has been associated with autoimmunity in the past. We further explored this expansion of IGHV4–34 utilization during the peripheral PB rise with next generation sequencing (NGS) analysis and utilizing newer techniques of chromium chip single cell separation (10x Genomics®). We also utilized peptide array screening to attempt to identify an antigen to the most prolific clones.

γδ T cells license immature B cells to produce a broad range of polyreactive antibodies

Rampoldi, Francesca; Donato, Elisa; Ullrich, Leon; Deseke, Malte; Janssen, Anika; Demera, Abdi; Sandrock, Inga; Bubke, Anja; Juergens, Anna-Lena; Swallow, Maxine; Sparwasser, Tim; Falk, Christine; Tan, Likai; Trumpp, Andreas; Prinz, Immo
Cell Reports.
May 2022
Immature autoreactive B cells are present in all healthy individuals, but it is unclear which signals are required for their maturation into antibody-producing cells. Inducible depletion of γδ T cells show that direct interaction between γδ T cells and immature B cells in the spleen support an “innate” transition to mature B cells with a broad range of antigen specificities. IL-4 production of γδ T cells and cell-to-cell contact via CD30L support B cell maturation and induce genes of the unfolded protein response and mTORC1 signaling. Eight days after in vivo depletion of γδ T cells, increased numbers of B cells are already stuck in the transitional phase and express increased levels of IgD and CD21. Absence of γδ T cells leads also to reduced levels of serum anti-nuclear autoantibodies, making γδ T cells an attractive target to treat autoimmunity.

Development of broadly neutralizing antibodies targeting the cytomegalovirus subdominant antigen gH

Parsons, Andrea J.; Ophir, Sabrina I.; Duty, J. Andrew; Kraus, Thomas A.; Stein, Kathryn R.; Moran, Thomas M.; Tortorella, Domenico
Commun Biol.
Apr 2022
Human cytomegalovirus (HCMV) is a β-herpesvirus that increases morbidity and mortality in immunocompromised individuals including transplant recipients and newborns. New anti-HCMV therapies are an urgent medical need for diverse patient populations. HCMV infection of a broad range of host tissues is dependent on the gH/gL/gO trimer and gH/gL/UL28/UL130/UL131A pentamer complexes on the viral envelope. We sought to develop safe and effective therapeutics against HCMV by generating broadly-neutralizing, human monoclonal antibodies (mAbs) from VelocImmune® mice immunized with gH/gL cDNA. Following high-throughput binding and neutralization screening assays, 11 neutralizing antibodies were identified with unique CDR3 regions and a high-affinity (KD 1.4-65 nM) to the pentamer complex. The antibodies bound to distinct regions within Domains 1 and 2 of gH and effectively neutralized diverse clinical strains in physiologically relevant cell types including epithelial cells, trophoblasts, and monocytes. Importantly, combined adminstration of mAbs with ganciclovir, an FDA approved antiviral, greatly limited virus dissemination. Our work identifies several anti-gH/gL mAbs and sheds light on gH neutralizing epitopes that can guide future vaccine strategies.

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