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BioRxiv : the Preprint Server For... May 2024Lyme disease is a tick-borne, multisystem infection caused by the spirochete, . Although antibodies have been implicated in the resolution of Lyme disease, the specific...
Lyme disease is a tick-borne, multisystem infection caused by the spirochete, . Although antibodies have been implicated in the resolution of Lyme disease, the specific B cell epitopes targeted during human infections remain largely unknown. In this study, we characterized and defined the structural epitope of a patient-derived bactericidal monoclonal IgG ("B11") against Outer surface protein C (OspC), a homodimeric lipoprotein necessary for tick-mediated transmission and early-stage colonization of vertebrate hosts. High-resolution epitope mapping was accomplished through hydrogen deuterium exchange-mass spectrometry (HDX-MS) and X-ray crystallography. Structural analysis of B11 Fab-OspC complexes revealed the B11 Fabs associated in a 1:1 stoichiometry with the lateral faces of OspC homodimers such that the antibodies are essentially positioned perpendicular to the spirochete's outer surface. B11's primary contacts reside within the membrane proximal regions of α-helices 1 and 6 and adjacent loops 5 and 6 in one OspC monomer. In addition, B11 spans the OspC dimer interface, engaging opposing α-helix 1', α-helix 2', and loop 2-3' in the second OspC monomer. The B11-OspC structure is reminiscent of the recently solved mouse transmission blocking monoclonal IgG B5 in complex with OspC , indicating a mode of engagement with OspC that is conserved across species. In conclusion, we provide the first detailed insight into the interaction between a functional human antibody and an immunodominant Lyme disease antigen long considered an important vaccine target.
PubMed: 38746285
DOI: 10.1101/2024.04.29.591597 -
Frontiers in Cardiovascular Medicine 2024The establishment of new blood vessels, and their subsequent stabilization, is a critical process that facilitates tissue growth and organ development. Once established,... (Review)
Review
The establishment of new blood vessels, and their subsequent stabilization, is a critical process that facilitates tissue growth and organ development. Once established, vessels need to diversify to meet the specific needs of the local tissue and to maintain homeostasis. These processes are tightly regulated and fundamental to normal vessel and tissue function. The mechanisms that orchestrate angiogenesis and vessel maturation have been widely studied, with signaling crosstalk between endothelium and perivascular cells being identified as an essential component. In disease, however, new vessels develop abnormally, and existing vessels lose their specialization and function, which invariably contributes to disease progression. Despite considerable research into the vasculopathic mechanisms in disease, our knowledge remains incomplete. Accordingly, the identification of angiocrine and angiopathic molecules secreted by cells within the vascular microenvironment, and their effect on vessel behaviour, remains a major research objective. Over the last decade the secreted glycoprotein leucine-rich α-2 glycoprotein 1 (LRG1), has emerged as a significant vasculopathic molecule, stimulating defective angiogenesis, and destabilizing the existing vasculature mainly, but not uniquely, by altering both canonical and non-canonical TGF-β signaling in a highly cell and context dependent manner. Whilst LRG1 does not possess any overt homeostatic role in vessel development and maintenance, growing evidence provides a compelling case for LRG1 playing a pleiotropic role in disrupting the vasculature in many disease settings. Thus, LRG1 has now been reported to damage vessels in various disorders including cancer, diabetes, chronic kidney disease, ocular disease, and lung disease and the signaling processes that drive this dysfunction are being defined. Moreover, therapeutic targeting of LRG1 has been widely proposed to re-establish a quiescent endothelium and normalized vasculature. In this review, we consider the current status of our understanding of the role of LRG1 in vascular pathology, and its potential as a therapeutic target.
PubMed: 38745756
DOI: 10.3389/fcvm.2024.1386177 -
Frontiers in Immunology 2024Among spp. responsible for human malaria, ranks as the second most prevalent and has the widest geographical range; however, vaccine development has lagged behind that...
Among spp. responsible for human malaria, ranks as the second most prevalent and has the widest geographical range; however, vaccine development has lagged behind that of , the deadliest species. Recently, we developed a multistage vaccine for based on a heterologous prime-boost immunization regimen utilizing the attenuated vaccinia virus strain LC16m8Δ (m8Δ)-prime and adeno-associated virus type 1 (AAV1)-boost, and demonstrated 100% protection and more than 95% transmission-blocking (TB) activity in the mouse model. In this study, we report the feasibility and versatility of this vaccine platform as a multistage vaccine, which can provide 100% sterile protection against sporozoite challenge and >95% TB efficacy in the mouse model. Our vaccine comprises m8Δ and AAV1 viral vectors, both harboring the gene encoding two circumsporozoite (PvCSP) protein alleles (VK210; PvCSP-Sal and VK247; -PNG) and P25 (Pvs25) expressed as a Pvs25-PvCSP fusion protein. For protective efficacy, the heterologous m8Δ-prime/AAV1-boost immunization regimen showed 100% (short-term; Day 28) and 60% (long-term; Day 242) protection against PvCSP VK210 transgenic sporozoites. For TB efficacy, mouse sera immunized with the vaccine formulation showed >75% TB activity and >95% transmission reduction activity by a direct membrane feeding assay using isolates in blood from an infected patient from the Brazilian Amazon region. These findings provide proof-of-concept that the m8Δ/AAV1 vaccine platform is sufficiently versatile for vaccine development. Future studies are needed to evaluate the safety, immunogenicity, vaccine efficacy, and synergistic effects on protection and transmission blockade in a non-human primate model for Phase I trials.
Topics: Animals; Malaria Vaccines; Plasmodium vivax; Malaria, Vivax; Mice; Genetic Vectors; Dependovirus; Female; Protozoan Proteins; Antibodies, Protozoan; Disease Models, Animal; Vaccinia virus; Humans; Mice, Inbred BALB C; Immunization, Secondary; Vaccine Efficacy
PubMed: 38745665
DOI: 10.3389/fimmu.2024.1372584 -
Inflammatory risk contributes to post-COVID endothelial dysfunction through anti-ACKR1 autoantibody.Life Science Alliance Jul 2024Subclinical vascular impairment can be exacerbated in individuals who experience sustained inflammation after COVID-19 infection. Our study explores the prevalence and...
Subclinical vascular impairment can be exacerbated in individuals who experience sustained inflammation after COVID-19 infection. Our study explores the prevalence and impact of autoantibodies on vascular dysfunction in healthy COVID-19 survivors, an area that remains inadequately investigated. Focusing on autoantibodies against the atypical chemokine receptor 1 (ACKR1), COVID-19 survivors demonstrated significantly elevated anti-ACKR1 autoantibodies, correlating with systemic cytokines, circulating damaged endothelial cells, and endothelial dysfunction. An independent cohort linked these autoantibodies to increased vascular disease outcomes during a median 6.7-yr follow-up. We analyzed a single-cell transcriptome atlas of endothelial cells from diverse mouse tissues, identifying enriched expressions in venous regions of the brain and soleus muscle vasculatures, which holds intriguing implications for tissue-specific venous thromboembolism manifestations reported in COVID-19. Functionally, purified immunoglobulin G (IgG) extracted from patient plasma did not trigger cell apoptosis or increase barrier permeability in human vein endothelial cells. Instead, plasma IgG enhanced antibody-dependent cellular cytotoxicity mediated by patient PBMCs, a phenomenon alleviated by blocking peptide or liposome ACKR1 recombinant protein. The blocking peptide uncovered that purified IgG from COVID-19 survivors possessed potential epitopes in the N-terminal extracellular domain of ACKR1, which effectively averted antibody-dependent cellular cytotoxicity. Our findings offer insights into therapeutic development to mitigate autoantibody reactivity in blood vessels in chronic inflammation.
Topics: Humans; Autoantibodies; COVID-19; Animals; Mice; Female; Male; SARS-CoV-2; Inflammation; Middle Aged; Endothelium, Vascular; Immunoglobulin G; Endothelial Cells; Adult; Aged
PubMed: 38740432
DOI: 10.26508/lsa.202402598 -
Frontiers in Molecular Biosciences 2024Despite an array of hypothesised implications for health, disease, and therapeutic development, antibodies against the non-human sialic acid -glycolylneuraminic acid... (Review)
Review
A systematic review reveals conflicting evidence for the prevalence of antibodies against the sialic acid 'xenoautoantigen' Neu5Gc in humans and the need for a standardised approach to quantification.
Despite an array of hypothesised implications for health, disease, and therapeutic development, antibodies against the non-human sialic acid -glycolylneuraminic acid (Neu5Gc) remain a subject of much debate. This systematic review of 114 publications aimed to generate a comprehensive overview of published studies in this field, addressing both the reported prevalence of anti-Neu5Gc antibodies in the human population and whether experimental variation accounts for the conflicting reports about the extent of this response. Absolute titres of anti-Neu5Gc antibodies, the reported prevalence of these antibodies, and the individual variation observed within experiments were analysed and grouped according to biological context ('inflammation', 'xenotransplantation', 'biotherapeutic use', 'cancer', and 'healthy populations'), detection method, target epitope selection, and choice of blocking agent. These analyses revealed that the experimental method had a notable impact on both the reported prevalence and absolute titres of anti-Neu5Gc antibodies in the general population, thereby limiting the ability to ascribe reported trends to genuine biological differences or the consequence of experimental design. Overall, this review highlights important knowledge gaps in the study of antibodies against this important xenoautoantigen and the need to establish a standardised method for their quantification if the extent of the importance of Neu5Gc in human health is to be fully understood.
PubMed: 38737334
DOI: 10.3389/fmolb.2024.1390711 -
Proceedings of the Japan Academy.... 2024Multifunctional molecules involved in tumor progression and metastasis have been identified as valuable targets for immunotherapy. Among these, chondroitin sulfate... (Review)
Review
Multifunctional molecules involved in tumor progression and metastasis have been identified as valuable targets for immunotherapy. Among these, chondroitin sulfate proteoglycan 4 (CSPG4), a significant tumor cell membrane-bound proteoglycan, has emerged as a promising target, especially in light of advances in chimeric antigen receptor (CAR) T-cell therapy. The profound bioactivity of CSPG4 and its role in pivotal processes such as tumor proliferation, migration, and neoangiogenesis underline its therapeutic potential. We reviewed the molecular intricacies of CSPG4, its functional attributes within tumor cells, and the latest clinical-translational advances targeting it. Strategies such as blocking monoclonal antibodies, conjugate therapies, bispecific antibodies, small-molecule inhibitors, CAR T-cell therapies, trispecific killer engagers, and ribonucleic acid vaccines against CSPG4 were assessed. CSPG4 overexpression in diverse tumors and its correlation with adverse prognostic outcomes emphasize its significance in cancer biology. These findings suggest that targeting CSPG4 offers a promising avenue for future cancer therapy, with potential synergistic effects when combined with existing treatments.
Topics: Humans; Immunotherapy; Neoplasms; Animals; Chondroitin Sulfate Proteoglycans; Proteoglycans; Molecular Targeted Therapy; Antibodies, Monoclonal; Antigens; Membrane Proteins
PubMed: 38735753
DOI: 10.2183/pjab.100.019 -
BMC Immunology May 2024Thyroid eye disease (TED) is an inflammatory process involving lymphocyte-mediated immune response and orbital tissue damage. The anti-insulin-like growth factor-1...
Potential role of IGF-1R in the interaction between orbital fibroblasts and B lymphocytes: an implication for B lymphocyte depletion in the active inflammatory phase of thyroid-associated ophthalmopathy.
BACKGROUND
Thyroid eye disease (TED) is an inflammatory process involving lymphocyte-mediated immune response and orbital tissue damage. The anti-insulin-like growth factor-1 receptor (IGF-1R) antibodies produced by B lymphocytes are involved in the activation of orbital fibroblasts and the inflammatory process of orbital tissue damage in TED. The purpose of this study was to explore the role of IGF-1R in the mechanistic connection between orbital fibroblasts and B lymphocytes in TED.
METHODS
Orbital fibroblasts sampled from orbital connective tissues and peripheral B lymphocytes isolated from peripheral blood, which were obtained from 15 patients with TED and 15 control patients, were co-cultured at a ratio of 1:20. The level of IGF-1R expression in orbital fibroblasts was evaluated by flow cytometry and confocal microscopy. Transient B lymphocyte depletion was induced with anti-CD20 monoclonal antibody rituximab, while the IGF-1R pathway was blocked by the IGF-1R binding protein. The expression levels of interleukin-6 (IL-6) and regulated upon activation, normal T cell expressed and secreted (RANTES) in the co-culture model were quantified via ELISA.
RESULTS
IGF-1R expression was significantly elevated in TED orbital fibroblasts compared to that of controls. A 24-h co-culture of orbital fibroblasts with peripheral B lymphocytes induced elevated expression levels of IL-6 and RANTES in each group (TED patients and controls), with the highest levels occurring in TED patients (T + T group). Rituximab and IGF-1R binding protein significantly inhibited increased levels of IL-6 and RANTES in the co-culture model of TED patients.
CONCLUSIONS
IGF-1R may mediate interaction between orbital fibroblasts and peripheral B lymphocytes; thus, blocking IGF-1R may reduce the local inflammatory response in TED. Rituximab-mediated B lymphocyte depletion played a role in inhibiting inflammatory responses in this in vitro co-culture model, providing a theoretical basis for the clinical application of anti-CD20 monoclonal antibodies in TED.
Topics: Humans; Graves Ophthalmopathy; Fibroblasts; Receptor, IGF Type 1; B-Lymphocytes; Female; Coculture Techniques; Male; Middle Aged; Adult; Rituximab; Orbit; Lymphocyte Depletion; Interleukin-6; Cells, Cultured; Chemokine CCL5; Cell Communication; Aged
PubMed: 38734625
DOI: 10.1186/s12865-024-00613-3 -
BMC Immunology May 2024Several PD-1 antibodies approved as anti-cancer therapies work by blocking the interaction of PD-1 with its ligand PD-L1, thus restoring anti-cancer T cell activities....
BACKGROUND
Several PD-1 antibodies approved as anti-cancer therapies work by blocking the interaction of PD-1 with its ligand PD-L1, thus restoring anti-cancer T cell activities. These PD-1 antibodies lack inter-species cross-reactivity, necessitating surrogate antibodies for preclinical studies, which may limit the predictability and translatability of the studies.
RESULTS
To overcome this limitation, we have developed an inter-species cross-reactive PD-1 antibody, GNUV201, by utilizing an enhanced diversity mouse platform (SHINE MOUSE™). GNUV201 equally binds to human PD-1 and mouse PD-1, equally inhibits the binding of human PD-1/PD-L1 and mouse PD-1/PD-L1, and effectively suppresses tumor growth in syngeneic mouse models. The epitope of GNUV201 mapped to the "FG loop" of hPD-1, distinct from those of Keytruda ("C'D loop") and Opdivo (N-term). Notably, the structural feature where the protruding epitope loop fits into GNUV201's binding pocket supports the enhanced binding affinity due to slower dissociation (8.7 times slower than Keytruda). Furthermore, GNUV201 shows a stronger binding affinity at pH 6.0 (5.6 times strong than at pH 7.4), which mimics the hypoxic and acidic tumor microenvironment (TME). This phenomenon is not observed with marketed antibodies (Keytruda, Opdivo), implying that GNUV201 achieves more selective binding to and better occupancy on PD-1 in the TME.
CONCLUSIONS
In summary, GNUV201 exhibited enhanced affinity for PD-1 with slow dissociation and preferential binding in TME-mimicking low pH. Human/monkey/mouse inter-species cross-reactivity of GNUV201 could enable more predictable and translatable efficacy and toxicity preclinical studies. These results suggest that GNUV201 could be an ideal antibody candidate for anti-cancer drug development.
Topics: Animals; Humans; Programmed Cell Death 1 Receptor; Mice; Cross Reactions; Immunotherapy; Hydrogen-Ion Concentration; Neoplasms; B7-H1 Antigen; Cell Line, Tumor; Antibodies, Monoclonal; Immune Checkpoint Inhibitors; Epitopes; Antibodies, Monoclonal, Humanized; Mice, Inbred C57BL; Female
PubMed: 38730320
DOI: 10.1186/s12865-024-00609-z -
American Society of Clinical Oncology... Jun 2024Combination chemotherapy with or without radiation has served as the primary therapeutic option for classic Hodgkin lymphoma (cHL), leading to durable remission in a... (Review)
Review
Combination chemotherapy with or without radiation has served as the primary therapeutic option for classic Hodgkin lymphoma (cHL), leading to durable remission in a majority of patients with early- and advanced-stage cHL. Patients with relapsed/refractory (RR) cHL could still be cured with salvage chemotherapy and autologous stem-cell transplantation. Brentuximab vedotin (BV) and the anti-PD-1-blocking antibodies, nivolumab and pembrolizumab, are highly effective treatments for cHL and have revolutionized the management of the disease. Recent studies incorporating BV and PD-1 blockade into salvage therapy for RR cHL and into frontline treatment regimens have changed the cHL treatment paradigm. The novel agents are also useful in the treatment of older patients who have poor outcomes with traditional therapy. This manuscript will review current strategies for approaching the management of previously untreated, RR, and challenging populations with cHL, including how to incorporate the novel agents.
Topics: Hodgkin Disease; Humans; Antineoplastic Combined Chemotherapy Protocols; Neoplasm Recurrence, Local; Combined Modality Therapy; Salvage Therapy; Treatment Outcome; Immune Checkpoint Inhibitors; Disease Management; Recurrence
PubMed: 38728605
DOI: 10.1200/EDBK_433502 -
Cells Apr 2024Natural killer (NK) cells can migrate quickly to the tumor site to exert cytotoxic effects on tumors, and some chemokines, including CXCL8, CXCL10 or and CXCL12, can...
Natural killer (NK) cells can migrate quickly to the tumor site to exert cytotoxic effects on tumors, and some chemokines, including CXCL8, CXCL10 or and CXCL12, can regulate the migration of NK cells. Activin A, a member of the transforming growth factor β (TGF-β) superfamily, is highly expressed in tumor tissues and involved in tumor development and immune cell activation. In this study, we focus on the effects of activin A on NK cell migration. In vitro, activin A induced NK cell migration and invasion, promoted cell polarization and inhibited cell adhesion. Moreover, activin A increased Ca, p-SMAD3 and p-AKT levels in NK cells. An AKT inhibitor and Ca chelator partially blocked activin A-induced NK cell migration. In vivo, exogenous activin A increased tumor-infiltrating NK cells in NS-1 cell solid tumors and inhibited tumor growth, and blocking endogenous activin A with anti-activin A antibody reduced tumor-infiltrating NK cells in 4T-1 cell solid tumors. These results suggest that activin A induces NK cell migration through AKT signaling and calcium signaling and may enhance the antitumor effect of NK cells by increasing tumor-infiltrating NK cells.
Topics: Activins; Killer Cells, Natural; Animals; Cell Movement; Proto-Oncogene Proteins c-akt; Mice; Calcium Signaling; Cell Line, Tumor; Mice, Inbred C57BL
PubMed: 38727264
DOI: 10.3390/cells13090728