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1.
Nat Immunol ; 24(4): 604-611, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36879067

RESUMEN

Infection with severe acute respiratory syndrome coronavirus 2 associates with diverse symptoms, which can persist for months. While antiviral antibodies are protective, those targeting interferons and other immune factors are associated with adverse coronavirus disease 2019 (COVID-19) outcomes. Here we discovered that antibodies against specific chemokines were omnipresent post-COVID-19, were associated with favorable disease outcome and negatively correlated with the development of long COVID at 1 yr post-infection. Chemokine antibodies were also present in HIV-1 infection and autoimmune disorders, but they targeted different chemokines compared with COVID-19. Monoclonal antibodies derived from COVID-19 convalescents that bound to the chemokine N-loop impaired cell migration. Given the role of chemokines in orchestrating immune cell trafficking, naturally arising chemokine antibodies may modulate the inflammatory response and thus bear therapeutic potential.


Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Autoanticuerpos , Síndrome Post Agudo de COVID-19 , Quimiocinas
2.
Nat Immunol ; 23(2): 275-286, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35102342

RESUMEN

The humoral arm of innate immunity includes diverse molecules with antibody-like functions, some of which serve as disease severity biomarkers in coronavirus disease 2019 (COVID-19). The present study was designed to conduct a systematic investigation of the interaction of human humoral fluid-phase pattern recognition molecules (PRMs) with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Of 12 PRMs tested, the long pentraxin 3 (PTX3) and mannose-binding lectin (MBL) bound the viral nucleocapsid and spike proteins, respectively. MBL bound trimeric spike protein, including that of variants of concern (VoC), in a glycan-dependent manner and inhibited SARS-CoV-2 in three in vitro models. Moreover, after binding to spike protein, MBL activated the lectin pathway of complement activation. Based on retention of glycosylation sites and modeling, MBL was predicted to recognize the Omicron VoC. Genetic polymorphisms at the MBL2 locus were associated with disease severity. These results suggest that selected humoral fluid-phase PRMs can play an important role in resistance to, and pathogenesis of, COVID-19, a finding with translational implications.


Asunto(s)
COVID-19/inmunología , Inmunidad Humoral , Receptores de Reconocimiento de Patrones/inmunología , SARS-CoV-2/inmunología , Animales , Proteína C-Reactiva/inmunología , Proteína C-Reactiva/metabolismo , COVID-19/metabolismo , COVID-19/virología , Estudios de Casos y Controles , Chlorocebus aethiops , Activación de Complemento , Proteínas de la Nucleocápside de Coronavirus/genética , Proteínas de la Nucleocápside de Coronavirus/inmunología , Proteínas de la Nucleocápside de Coronavirus/metabolismo , Femenino , Glicosilación , Células HEK293 , Interacciones Huésped-Patógeno , Humanos , Masculino , Lectina de Unión a Manosa/genética , Lectina de Unión a Manosa/inmunología , Lectina de Unión a Manosa/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/inmunología , Fosfoproteínas/metabolismo , Polimorfismo Genético , Unión Proteica , Receptores de Reconocimiento de Patrones/genética , Receptores de Reconocimiento de Patrones/metabolismo , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidad , Componente Amiloide P Sérico/inmunología , Componente Amiloide P Sérico/metabolismo , Transducción de Señal , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Células Vero
3.
Cell ; 171(1): 229-241.e15, 2017 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-28938115

RESUMEN

Zika virus (ZIKV), a mosquito-borne flavivirus, causes devastating congenital birth defects. We isolated a human monoclonal antibody (mAb), ZKA190, that potently cross-neutralizes multi-lineage ZIKV strains. ZKA190 is highly effective in vivo in preventing morbidity and mortality of ZIKV-infected mice. NMR and cryo-electron microscopy show its binding to an exposed epitope on DIII of the E protein. ZKA190 Fab binds all 180 E protein copies, altering the virus quaternary arrangement and surface curvature. However, ZIKV escape mutants emerged in vitro and in vivo in the presence of ZKA190, as well as of other neutralizing mAbs. To counter this problem, we developed a bispecific antibody (FIT-1) comprising ZKA190 and a second mAb specific for DII of E protein. In addition to retaining high in vitro and in vivo potencies, FIT-1 robustly prevented viral escape, warranting its development as a ZIKV immunotherapy.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/uso terapéutico , Anticuerpos Antivirales/uso terapéutico , Infección por el Virus Zika/terapia , Virus Zika/química , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/química , Anticuerpos Neutralizantes/administración & dosificación , Anticuerpos Neutralizantes/química , Anticuerpos Antivirales/administración & dosificación , Anticuerpos Antivirales/química , Microscopía por Crioelectrón , Epítopos , Humanos , Espectroscopía de Resonancia Magnética , Ratones , Modelos Moleculares , Alineación de Secuencia , Proteínas del Envoltorio Viral/química , Virus Zika/inmunología
5.
Nature ; 593(7859): 424-428, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33767445

RESUMEN

Neutralizing antibodies that target the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein are among the most promising approaches against COVID-191,2. A bispecific IgG1-like molecule (CoV-X2) has been developed on the basis of C121 and C135, two antibodies derived from donors who had recovered from COVID-193. Here we show that CoV-X2 simultaneously binds two independent sites on the RBD and, unlike its parental antibodies, prevents detectable spike binding to the cellular receptor of the virus, angiotensin-converting enzyme 2 (ACE2). Furthermore, CoV-X2 neutralizes wild-type SARS-CoV-2 and its variants of concern, as well as escape mutants generated by the parental monoclonal antibodies. We also found that in a mouse model of SARS-CoV-2 infection with lung inflammation, CoV-X2 protects mice from disease and suppresses viral escape. Thus, the simultaneous targeting of non-overlapping RBD epitopes by IgG-like bispecific antibodies is feasible and effective, and combines the advantages of antibody cocktails with those of single-molecule approaches.


Asunto(s)
Anticuerpos Biespecíficos/inmunología , Anticuerpos Neutralizantes/inmunología , COVID-19/inmunología , COVID-19/virología , Inmunoglobulina G/inmunología , SARS-CoV-2/inmunología , Enzima Convertidora de Angiotensina 2/antagonistas & inhibidores , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , Anticuerpos Biespecíficos/uso terapéutico , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/uso terapéutico , Peso Corporal , COVID-19/prevención & control , Dependovirus/genética , Modelos Animales de Enfermedad , Epítopos de Linfocito B/química , Epítopos de Linfocito B/inmunología , Femenino , Humanos , Evasión Inmune/genética , Ratones , Ratones Endogámicos C57BL , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/antagonistas & inhibidores , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Tratamiento Farmacológico de COVID-19
6.
Proc Natl Acad Sci U S A ; 121(3): e2315354120, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38194459

RESUMEN

The emergence of Omicron lineages and descendent subvariants continues to present a severe threat to the effectiveness of vaccines and therapeutic antibodies. We have previously suggested that an insufficient mucosal immunoglobulin A (IgA) response induced by the mRNA vaccines is associated with a surge in breakthrough infections. Here, we further show that the intramuscular mRNA and/or inactivated vaccines cannot sufficiently boost the mucosal secretory IgA response in uninfected individuals, particularly against the Omicron variant. We thus engineered and characterized recombinant monomeric, dimeric, and secretory IgA1 antibodies derived from four neutralizing IgG monoclonal antibodies (mAbs 01A05, rmAb23, DXP-604, and XG014) targeting the receptor-binding domain of the spike protein. Compared to their parental IgG antibodies, dimeric and secretory IgA1 antibodies showed a higher neutralizing activity against different variants of concern (VOCs), in part due to an increased avidity. Importantly, the dimeric or secretory IgA1 form of the DXP-604 antibody significantly outperformed its parental IgG antibody, and neutralized the Omicron lineages BA.1, BA.2, and BA.4/5 with a 25- to 75-fold increase in potency. In human angiotensin converting enzyme 2 (ACE2) transgenic mice, a single intranasal dose of the dimeric IgA DXP-604 conferred prophylactic and therapeutic protection against Omicron BA.5. Thus, dimeric or secretory IgA delivered by nasal administration may potentially be exploited for the treatment and prevention of Omicron infection, thereby providing an alternative tool for combating immune evasion by the current circulating subvariants and, potentially, future VOCs.


Asunto(s)
Anticuerpos Monoclonales , Inmunoglobulina A Secretora , Animales , Ratones , Humanos , Inmunoglobulina G , Inmunoglobulina A , Administración Intranasal , Ratones Transgénicos
7.
Int J Mol Sci ; 24(19)2023 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-37834322

RESUMEN

Analytical ultracentrifugation (AUC) analysis shows that the SARS-CoV-2 trimeric Spike (S) protein adopts different quaternary conformations in solution. The relative abundance of the "open" and "close" conformations is temperature-dependent, and samples with different storage temperature history have different open/close distributions. Neutralizing antibodies (NAbs) targeting the S receptor binding domain (RBD) do not alter the conformer populations; by contrast, a NAb targeting a cryptic conformational epitope skews the Spike trimer toward an open conformation. The results highlight AUC, which is typically applied for molecular mass determination of biomolecules as a powerful tool for detecting functionally relevant quaternary protein conformations.


Asunto(s)
SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Epítopos/química , Epítopos/inmunología , SARS-CoV-2/química , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Ultracentrifugación , Dominios Proteicos
9.
PLoS Pathog ; 14(10): e1007335, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30273408

RESUMEN

Antibodies to the prion protein, PrP, represent a promising therapeutic approach against prion diseases but the neurotoxicity of certain anti-PrP antibodies has caused concern. Here we describe scPOM-bi, a bispecific antibody designed to function as a molecular prion tweezer. scPOM-bi combines the complementarity-determining regions of the neurotoxic antibody POM1 and the neuroprotective POM2, which bind the globular domain (GD) and flexible tail (FT) respectively. We found that scPOM-bi confers protection to prion-infected organotypic cerebellar slices even when prion pathology is already conspicuous. Moreover, scPOM-bi prevents the formation of soluble oligomers that correlate with neurotoxic PrP species. Simultaneous targeting of both GD and FT was more effective than concomitant treatment with the individual molecules or targeting the tail alone, possibly by preventing the GD from entering a toxic-prone state. We conclude that simultaneous binding of the GD and flexible tail of PrP results in strong protection from prion neurotoxicity and may represent a promising strategy for anti-prion immunotherapy.


Asunto(s)
Anticuerpos Biespecíficos/farmacología , Cerebelo/inmunología , Inmunoterapia , Enfermedades por Prión/terapia , Proteínas Priónicas/inmunología , Priones/toxicidad , Animales , Anticuerpos Biespecíficos/inmunología , Células Cultivadas , Regiones Determinantes de Complementariedad/inmunología , Ratones , Ratones Transgénicos , Enfermedades por Prión/inmunología , Priones/inmunología
10.
Proc Natl Acad Sci U S A ; 112(33): 10473-8, 2015 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-26216974

RESUMEN

Middle East Respiratory Syndrome (MERS) is a highly lethal pulmonary infection caused by a previously unidentified coronavirus (CoV), likely transmitted to humans by infected camels. There is no licensed vaccine or antiviral for MERS, therefore new prophylactic and therapeutic strategies to combat human infections are needed. In this study, we describe, for the first time, to our knowledge, the isolation of a potent MERS-CoV-neutralizing antibody from memory B cells of an infected individual. The antibody, named LCA60, binds to a novel site on the spike protein and potently neutralizes infection of multiple MERS-CoV isolates by interfering with the binding to the cellular receptor CD26. Importantly, using mice transduced with adenovirus expressing human CD26 and infected with MERS-CoV, we show that LCA60 can effectively protect in both prophylactic and postexposure settings. This antibody can be used for prophylaxis, for postexposure prophylaxis of individuals at risk, or for the treatment of human cases of MERS-CoV infection. The fact that it took only 4 mo from the initial screening of B cells derived from a convalescent patient for the development of a stable chinese hamster ovary (CHO) cell line producing neutralizing antibodies at more than 5 g/L provides an example of a rapid pathway toward the generation of effective antiviral therapies against emerging viruses.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Memoria Inmunológica , Coronavirus del Síndrome Respiratorio de Oriente Medio/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Linfocitos B/inmunología , Sitios de Unión , Células CHO , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Cricetinae , Cricetulus , Dipeptidil Peptidasa 4/química , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Persona de Mediana Edad , Conformación Molecular , Datos de Secuencia Molecular , Mutación , Unión Proteica , Homología de Secuencia de Aminoácido , Glicoproteína de la Espiga del Coronavirus/química , Vacunas Virales
11.
J Virol ; 90(4): 1802-11, 2016 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-26637461

RESUMEN

UNLABELLED: Domain III of dengue virus E protein (DIII) participates in the recognition of cell receptors and in structural rearrangements required for membrane fusion and ultimately viral infection; furthermore, it contains epitopes for neutralizing antibodies and has been considered a potential vaccination agent. In this work, we addressed various structural aspects of DIII and their relevance for both the dengue virus infection mechanism and antibody recognition. We provided a dynamic description of DIII at physiological and endosomal pHs and in complex with the neutralizing human antibody DV32.6. We observed conformational exchange in the isolated DIII, in regions important for the packing of E protein dimers on the virus surface. This conformational diversity is likely to facilitate the partial detachment of DIII from the other E protein domains, which is required to achieve fusion to the host cellular membranes and to expose the epitopes of many anti-DIII antibodies. A comparison of DIII of two dengue virus serotypes revealed many common features but also some possibly unexpected differences. Antibody binding to DIII of dengue virus serotype 4 attenuated the conformational exchange in the epitope region but, surprisingly, generated exchange in other parts of DIII through allosteric effects. IMPORTANCE: Many studies have provided extensive structural information on the E protein and particularly on DIII, also in complex with antibodies. However, there is very scarce information regarding the molecular dynamics of DIII, and almost nothing is available on the dynamic effect of antibody binding, especially at the quantitative level. This work provides one of the very rare descriptions of the effect of antibody binding on antigen dynamics.


Asunto(s)
Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/metabolismo , Humanos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Unión Proteica , Conformación Proteica/efectos de los fármacos , Estructura Terciaria de Proteína
12.
Anal Bioanal Chem ; 405(29): 9427-36, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24081568

RESUMEN

A high-throughput bioaffinity liquid chromatography-mass spectrometry (BioMS) approach was developed and applied for the screening and identification of recombinant human estrogen receptor α (ERα) ligands in dietary supplements. For screening, a semi-automated mass spectrometric ligand binding assay was developed applying (13)C2, (15) N-tamoxifen as non-radioactive label and fast ultra-high-performance-liquid chromatography-electrospray ionisation-triple-quadrupole-MS (UPLC-QqQ-MS), operated in the single reaction monitoring mode, as a readout system. Binding of the label to ERα-coated paramagnetic microbeads was inhibited by competing estrogens in the sample extract yielding decreased levels of the label in UPLC-QqQ-MS. The label showed high ionisation efficiency in positive electrospray ionisation (ESI) mode, so the developed BioMS approach is able to screen for estrogens in dietary supplements despite their poor ionisation efficiency in both positive and negative ESI modes. The assay was performed in a 96-well plate, and all these wells could be measured within 3 h. Estrogens in suspect extracts were identified by full-scan accurate mass and collision-cross section (CCS) values from a UPLC-ion mobility-Q-time-of-flight-MS (UPLC-IM-Q-ToF-MS) equipped with a novel atmospheric pressure ionisation source. Thanks to the novel ion source, this instrument provided picogram sensitivity for estrogens in the negative ion mode and an additional identification point (experimental CCS values) next to retention time, accurate mass and tandem mass spectrometry data. The developed combination of bioaffinity screening with UPLC-QqQ-MS and identification with UPLC-IM-Q-ToF-MS provides an extremely powerful analytical tool for early warning of ERα bioactive compounds in dietary supplements as demonstrated by analysis of selected dietary supplements in which different estrogens were identified.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Suplementos Dietéticos/análisis , Receptor alfa de Estrógeno/química , Estrógenos/química , Ensayos Analíticos de Alto Rendimiento/métodos , Espectrometría de Masas/métodos , Humanos , Unión Proteica
13.
Glob Chall ; 7(10): 2300088, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37829677

RESUMEN

Neutralizing monoclonal antibodies have achieved great efficacy and safety for the treatment of numerous infectious diseases. However, their neutralization potency is often rapidly lost when the target antigen mutates. Instead of isolating new antibodies each time a pathogen variant arises, it can be attractive to adapt existing antibodies, making them active against the new variant. Potential benefits of this approach include reduced development time, cost, and regulatory burden. Here a methodology is described to rapidly evolve neutralizing antibodies of proven activity, improving their function against new pathogen variants without losing efficacy against previous ones. The reported procedure is based on structure-guided affinity maturation using combinatorial mutagenesis and phage display technology. Its use against the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is demonstrated, but it is suitable for any other pathogen. As proof of concept, the method is applied to CoV-X2, a human bispecific antibody that binds with high affinity to the early SARS-CoV-2 variants but lost neutralization potency against Delta. Antibodies emerging from the affinity maturation selection exhibit significantly improved neutralization potency against Delta and no loss of efficacy against the other viral sequences tested. These results illustrate the potential application of structure-guided affinity maturation in facilitating the rapid adaptation of neutralizing antibodies to pathogen variants.

14.
iScience ; 26(4): 106562, 2023 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-37063467

RESUMEN

This study reports the isolation and characterization of a human monoclonal antibody (mAb) called 19n01. This mAb was isolated by using single-cell RNAseq of B cells from donors infected with the ancestral strain. This mAb possesses a potent and broad capacity to bind and neutralize all previously circulating variants of concern (VOCs), including Omicron sublineages BA.1, BA.2, and BA.4/5. The pseudovirus neutralization assay revealed robust neutralization capacity against the G614 strain, BA.1, BA.2, and BA.4/5, with inhibitory concentration (IC50) values ranging from 0.0035 to 0.0164 µg/mL. The microneutralization assay using the G614 strain and VOCs demonstrated IC50 values of 0.013-0.267 µg/mL. Biophysical and structural analysis showed that 19n01 cross-competes with ACE2 binding to the receptor-binding domain (RBD) and the kinetic parameters confirmed the high affinity against the Omicron sublineages (KD of 61 and 30 nM for BA.2 and BA.4/5, respectively). These results suggest that the 19n01 is a remarkably potent and broadly reactive mAb.

15.
Cancer Cell ; 41(3): 602-619.e11, 2023 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-36868226

RESUMEN

Tumor cells promote the recruitment of immunosuppressive neutrophils, a subset of myeloid cells driving immune suppression, tumor proliferation, and treatment resistance. Physiologically, neutrophils are known to have a short half-life. Here, we report the identification of a subset of neutrophils that have upregulated expression of cellular senescence markers and persist in the tumor microenvironment. Senescent-like neutrophils express the triggering receptor expressed on myeloid cells 2 (TREM2) and are more immunosuppressive and tumor-promoting than canonical immunosuppressive neutrophils. Genetic and pharmacological elimination of senescent-like neutrophils decreases tumor progression in different mouse models of prostate cancer. Mechanistically, we have found that apolipoprotein E (APOE) secreted by prostate tumor cells binds TREM2 on neutrophils, promoting their senescence. APOE and TREM2 expression increases in prostate cancers and correlates with poor prognosis. Collectively, these results reveal an alternative mechanism of tumor immune evasion and support the development of immune senolytics targeting senescent-like neutrophils for cancer therapy.


Asunto(s)
Apolipoproteínas E , Neoplasias de la Próstata , Animales , Humanos , Masculino , Ratones , Apolipoproteínas E/metabolismo , Senescencia Celular/genética , Glicoproteínas de Membrana/genética , Células Mieloides/metabolismo , Neoplasias de la Próstata/metabolismo , Receptores Inmunológicos/metabolismo , Microambiente Tumoral
16.
Sci Immunol ; 8(81): eade0958, 2023 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-36701425

RESUMEN

Emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants diminishes the efficacy of vaccines and antiviral monoclonal antibodies. Continued development of immunotherapies and vaccine immunogens resilient to viral evolution is therefore necessary. Using coldspot-guided antibody discovery, a screening approach that focuses on portions of the virus spike glycoprotein that are both functionally relevant and averse to change, we identified human neutralizing antibodies to highly conserved viral epitopes. Antibody fp.006 binds the fusion peptide and cross-reacts against coronaviruses of the four genera, including the nine human coronaviruses, through recognition of a conserved motif that includes the S2' site of proteolytic cleavage. Antibody hr2.016 targets the stem helix and neutralizes SARS-CoV-2 variants. Antibody sd1.040 binds to subdomain 1, synergizes with antibody rbd.042 for neutralization, and, similar to fp.006 and hr2.016, protects mice expressing human angiotensin-converting enzyme 2 against infection when present as a bispecific antibody. Thus, coldspot-guided antibody discovery reveals donor-derived neutralizing antibodies that are cross-reactive with Orthocoronavirinae, including SARS-CoV-2 variants.


Asunto(s)
Anticuerpos Neutralizantes , COVID-19 , Humanos , Animales , Ratones , SARS-CoV-2 , Epítopos , Glicoproteína de la Espiga del Coronavirus , Anticuerpos Antivirales , Pruebas de Neutralización
17.
Nat Struct Mol Biol ; 29(8): 831-840, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35948768

RESUMEN

Prion infections cause conformational changes of the cellular prion protein (PrPC) and lead to progressive neurological impairment. Here we show that toxic, prion-mimetic ligands induce an intramolecular R208-H140 hydrogen bond ('H-latch'), altering the flexibility of the α2-α3 and ß2-α2 loops of PrPC. Expression of a PrP2Cys mutant mimicking the H-latch was constitutively toxic, whereas a PrPR207A mutant unable to form the H-latch conferred resistance to prion infection. High-affinity ligands that prevented H-latch induction repressed prion-related neurodegeneration in organotypic cerebellar cultures. We then selected phage-displayed ligands binding wild-type PrPC, but not PrP2Cys. These binders depopulated H-latched conformers and conferred protection against prion toxicity. Finally, brain-specific expression of an antibody rationally designed to prevent H-latch formation prolonged the life of prion-infected mice despite unhampered prion propagation, confirming that the H-latch is an important reporter of prion neurotoxicity.


Asunto(s)
Proteínas PrPC , Priones , Animales , Anticuerpos/metabolismo , Cerebelo/metabolismo , Ligandos , Ratones , Proteínas PrPC/química , Proteínas PrPC/genética , Proteínas Priónicas/química , Proteínas Priónicas/genética , Proteínas Priónicas/metabolismo , Priones/metabolismo , Priones/toxicidad
18.
bioRxiv ; 2022 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-36482967

RESUMEN

Emergence of SARS-CoV-2 variants diminishes the efficacy of vaccines and antiviral monoclonal antibodies. Continued development of immunotherapies and vaccine immunogens resilient to viral evolution is therefore necessary. Using coldspot-guided antibody discovery, a screening approach that focuses on portions of the virus spike that are both functionally relevant and averse to change, we identified human neutralizing antibodies to highly conserved viral epitopes. Antibody fp.006 binds the fusion peptide and cross-reacts against coronaviruses of the four genera , including the nine human coronaviruses, through recognition of a conserved motif that includes the S2' site of proteolytic cleavage. Antibody hr2.016 targets the stem helix and neutralizes SARS-CoV-2 variants. Antibody sd1.040 binds to subdomain 1, synergizes with antibody rbd.042 for neutralization and, like fp.006 and hr2.016, protects mice when present as bispecific antibody. Thus, coldspot-guided antibody discovery reveals donor-derived neutralizing antibodies that are cross-reactive with Orthocoronavirinae , including SARS-CoV-2 variants. One sentence summary: Broadly cross-reactive antibodies that protect from SARS-CoV-2 variants are revealed by virus coldspot-driven discovery.

19.
bioRxiv ; 2022 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-35664993

RESUMEN

Infection by SARS-CoV-2 leads to diverse symptoms, which can persist for months. While antiviral antibodies are protective, those targeting interferons and other immune factors are associated with adverse COVID-19 outcomes. Instead, we discovered that antibodies against specific chemokines are omnipresent after COVID-19, associated with favorable disease, and predictive of lack of long COVID symptoms at one year post infection. Anti-chemokine antibodies are present also in HIV-1 infection and autoimmune disorders, but they target different chemokines than those in COVID-19. Monoclonal antibodies derived from COVID- 19 convalescents that bind to the chemokine N-loop impair cell migration. Given the role of chemokines in orchestrating immune cell trafficking, naturally arising anti-chemokine antibodies associated with favorable COVID-19 may be beneficial by modulating the inflammatory response and thus bear therapeutic potential. One-Sentence Summary: Naturally arising anti-chemokine antibodies associate with favorable COVID-19 and predict lack of long COVID.

20.
Int J Mol Sci ; 12(1): 226-51, 2011 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-21339984

RESUMEN

Antibodies play an increasingly important role in both basic research and the pharmaceutical industry. Since their efficiency depends, in ultimate analysis, on their atomic interactions with an antigen, studying such interactions is important to understand how they function and, in the long run, to design new molecules with desired properties. Computational docking, the process of predicting the conformation of a complex from its separated components, is emerging as a fast and affordable technique for the structural characterization of antibody-antigen complexes. In this manuscript, we first describe the different computational strategies for the modeling of antibodies and docking of their complexes, and then predict the binding of two antibodies to the stalk region of influenza hemagglutinin, an important pharmaceutical target. The purpose is two-fold: on a general note, we want to illustrate the advantages and pitfalls of computational docking with a practical example, using different approaches and comparing the results to known experimental structures. On a more specific note, we want to assess if docking can be successful in characterizing the binding to the same influenza epitope of other antibodies with unknown structure, which has practical relevance for pharmaceutical and biological research. The paper clearly shows that some of the computational docking predictions can be very accurate, but the algorithm often fails to discriminate them from inaccurate solutions. It is of paramount importance, therefore, to use rapidly obtained experimental data to validate the computational results.


Asunto(s)
Complejo Antígeno-Anticuerpo/química , Complejo Antígeno-Anticuerpo/metabolismo , Biología Computacional/métodos , Hemaglutininas/química , Hemaglutininas/metabolismo , Virus de la Influenza A/metabolismo , Humanos
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