scholarly journals Novel neutralizing human monoclonal antibodies against tetanus neurotoxin

2021 ◽  
Author(s):  
Takeharu Minamitani ◽  
Karin Kiyose ◽  
Ryota Otsubo ◽  
Toshihiro Ito ◽  
Hiroki Akiba ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Protein Domain ◽  
Human Antibody ◽  
Human Monoclonal Antibodies ◽  
Fatal Disease ◽  
Peripheral Blood Mononuclear ◽  
Tetanus Neurotoxin ◽  
C Terminus ◽  
Reactive Antibody

Abstract Tetanus is a fatal disease caused by tetanus neurotoxin (TeNT). TeNT is composed of a light chain (Lc) and a heavy chain, the latter of which is classified into two domains, N-terminus Hn and C-terminus Hc. Several TeNT-neutralizing antibodies have been reported, but it remains unclear which TeNT domains are involved in neutralization. To further understand the mechanism of these antibodies, we isolated TeNT-reactive human antibody clones from peripheral blood mononuclear cells. We then analyzed the reactivity of the isolated antibody clones to each protein domain and their inhibition of Hc-ganglioside GT1b binding, which is critical for TeNT toxicity. We also investigated the TeNT-neutralizing ability of isolated antibody clones and showed that Hn-reactive clones protected strongly against TeNT toxicity in mice. Furthermore, combination treatment of Hn-reactive antibody clones with both Hc-reactive and TeNT mix–reactive antibody clones enhanced the neutralizing effect. These results indicated that antibody clones targeting Hn effectively neutralized TeNT. In addition, the use of a cocktail composed of Hc-, Hn-, and TeNT mix–reactive antibodies provided enhanced protection compared to the use of each antibody alone.

scholarly journals Novel neutralizing human monoclonal antibodies against tetanus neurotoxin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takeharu Minamitani ◽  
Karin Kiyose ◽  
Ryota Otsubo ◽  
Toshihiro Ito ◽  
Hiroki Akiba ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Protein Domain ◽  
Human Antibody ◽  
Human Monoclonal Antibodies ◽  
Fatal Disease ◽  
Peripheral Blood Mononuclear ◽  
Tetanus Neurotoxin ◽  
C Terminus ◽  
Reactive Antibody

AbstractTetanus is a fatal disease caused by tetanus neurotoxin (TeNT). TeNT is composed of a light chain (Lc) and a heavy chain, the latter of which is classified into two domains, N-terminus Hn and C-terminus Hc. Several TeNT-neutralizing antibodies have been reported, but it remains unclear which TeNT domains are involved in neutralization. To further understand the mechanism of these antibodies, we isolated TeNT-reactive human antibody clones from peripheral blood mononuclear cells. We then analyzed the reactivity of the isolated antibody clones to each protein domain and their inhibition of Hc-ganglioside GT1b binding, which is critical for TeNT toxicity. We also investigated the TeNT-neutralizing ability of isolated antibody clones and showed that an Hn-reactive clone protected strongly against TeNT toxicity in mice. Furthermore, combination treatment of Hn-reactive antibody clones with both Hc-reactive and TeNT mix (the mixture of Hc, Hn, and Lc proteins)–reactive antibody clones enhanced the neutralizing effect. These results indicated that antibody clones targeting Hn effectively neutralized TeNT. In addition, the use of a cocktail composed of Hc-, Hn-, and TeNT mix–reactive antibodies provided enhanced protection compared to the use of each antibody alone.

scholarly journals Viral Protein VP4 Is a Target of Human Antibodies Enhancing Coxsackievirus B4- and B3-Induced Synthesis of Alpha Interferon

2005 ◽  
Vol 79 (22) ◽  
pp. 13882-13891 ◽  
Author(s):  
Wassim Chehadeh ◽  
Pierre-Emmanuel Lobert ◽  
Pierre Sauter ◽  
Anne Goffard ◽  
Bernadette Lucas ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Insulin Dependent Diabetes Mellitus ◽  
Alpha Interferon ◽  
Dependent Diabetes Mellitus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peripheral Blood Mononuclear ◽  
Coxsackievirus B4

ABSTRACT Coxsackievirus B4 (CVB4)-induced production of alpha interferon (IFN-α) by peripheral blood mononuclear cells (PBMC) is enhanced in vitro by nonneutralizing anti-CVB4 antibodies from healthy subjects and, to a higher extent, from patients with insulin-dependent diabetes mellitus. In this study, we focused on identification of the viral target of these antibodies in CVB systems. High levels of IFN-α were obtained in supernatants of PBMC incubated with CVB4E2 or CVB3 and plasma from healthy subjects and, to a higher extent, from patients. The VP4 capsid proteins dissociated by heating at 56°C from CVB4E2 (VP4CVB4) and CVB3 (VP4CVB3) but not H antigen preincubated with plasma from healthy subjects or patients inhibited the plasma-dependent enhancement of CVB4E2- and CVB3-induced IFN-α synthesis. There was no cross-reaction between VP4CVB4 and VP4CVB3 in the inhibiting effect. IFN-α levels in culture supernatants showed dose-dependent correlation with anti-VP4 antibodies eluted from plasma specimens using VP4-coated plates. There were higher index values for anti-VP4 antibodies detected by enzyme-linked immunosorbent assay (ELISA) and higher proportions of positive detection in 40 patients than in 40 healthy subjects (80% versus 15% for anti-VP4CVB4). There was no relationship between the levels of anti-CVB neutralizing antibodies and the detection of anti-VP4 antibodies by ELISA. The CVB plasma-induced IFN-α levels obtained in PBMC cultures in the anti-VP4 antibody-positive groups were significantly higher than those obtained in the anti-VP4 antibody-negative groups regardless of the titers of anti-CVB neutralizing antibodies. These results show that VP4 is the target of antibodies involved in the plasma-dependent enhancement of CVB4E2- and CVB3-induced IFN-α synthesis by PBMC.

scholarly journals A New Genotype of Feline Morbillivirus Infects Primary Cells of the Lung, Kidney, Brain and Peripheral Blood

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 146 ◽  
Author(s):  
Michael Sieg ◽  
Johannes Busch ◽  
Maria Eschke ◽  
Denny Böttcher ◽  
Kristin Heenemann ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Peripheral Blood ◽  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Clinical Signs ◽  
Primary Cells ◽  
Peripheral Blood Mononuclear ◽  
New Genotype ◽  
Genotype 2 ◽  
Permanent Cell

Paramyxoviruses comprise a large number of diverse viruses which in part give rise to severe diseases in affected hosts. A new genotype of feline morbillivirus, tentatively named feline morbillivirus genotype 2 (FeMV-GT2), was isolated from urine of cats with urinary tract diseases. Whole genome sequencing showed about 78% nucleotide homology to known feline morbilliviruses. The virus was isolated in permanent cell lines of feline and simian origin. To investigate the cell tropism of FeMV-GT2 feline primary epithelial cells from the kidney, the urinary bladder and the lung, peripheral blood mononuclear cells (PBMC), as well as organotypic brain slice cultures were used for infection experiments. We demonstrate that FeMV-GT2 is able to infect renal and pulmonary epithelial cells, primary cells from the cerebrum and cerebellum, as well as immune cells in the blood, especially CD4+ T cells, CD20+ B cells and monocytes. The cats used for virus isolation shed FeMV-GT2 continuously for several months despite the presence of neutralizing antibodies in the blood. Our results point towards the necessity of increased awareness for this virus when clinical signs of the aforementioned organs are encountered in cats which cannot be explained by other etiologies.

scholarly journals Serum Interferon (IFN)-Neutralizing Antibodies and Bioactivities of IFNs in Patients with Severe Type II Essential Mixed Cryoglobulinemia

2003 ◽  
Vol 10 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Carolina Scagnolari ◽  
Milvia Casato ◽  
Francesca Bellomi ◽  
Francesca De Pisa ◽  
Ombretta Turriziani ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Clinical Response ◽  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Mixed Cryoglobulinemia ◽  
Mrna Levels ◽  
Type Ii ◽  
Essential Mixed Cryoglobulinemia ◽  
Peripheral Blood Mononuclear ◽  
Severe Type

ABSTRACT The efficacy of alpha interferon (IFN-α) in the treatment of severe type II essential mixed cryoglobulinemia (EMC) has been reported previously. In some patients, the development of neutralizing antibodies to recombinant IFN-α (rIFN-α) can affect the clinical response achieved with rIFN-α; a second treatment with natural IFN-α preparations may reinduce the clinical response. In the present study the ability of leukocyte IFN (LeIFN) to restore the response was investigated from a pharmacodynamic viewpoint. Specifically, the pharmacodynamic profiles of different IFN-α preparations were studied by measuring the serum neopterin levels and the levels of expression of protein MxA mRNA in in vivo peripheral blood mononuclear cells in two patients with EMC whose resistance to rIFN-α2a treatment increased concomitantly with the development of neutralizing antibodies. These markers were measured before injection and at 24 and 48 h after a single injection of rIFN-α2a, consensus IFN [(C)IFN], or LeIFN. No increase or only a slight increase in MxA mRNA levels was detectable after administration of rIFN-α2a or (C)IFN, whereas a significant increase (≥10-fold) in MxA mRNA expression was recorded following administration of LeIFN. The neutralizing antibodies to rIFN-α2a cross-react with (C)IFN. Sera from these patients neutralized most but not all of the subtypes present in the natural IFN-α (LeIFN) mixture, and no significant increase in neopterin levels was observed after these patients were switched to LeIFN treatment. In summary, the data demonstrate that the problem of neutralizing antibodies still exists and that LeIFN may induce an increase in the level of MxA mRNA expression but not an increase in neopterin levels in patients who are resistant to treatment with rIFN-α2a or (C)IFN.

scholarly journals Anti-phospholipid human monoclonal antibodies inhibit CCR5-tropic HIV-1 and induce β-chemokines

2010 ◽  
Vol 207 (4) ◽  
pp. 763-776 ◽  
Author(s):  
M. Anthony Moody ◽  
Hua-Xin Liao ◽  
S. Munir Alam ◽  
Richard M. Scearce ◽  
M. Kelly Plonk ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Virus Entry ◽  
Human Monoclonal Antibodies ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
Hiv 1

Traditional antibody-mediated neutralization of HIV-1 infection is thought to result from the binding of antibodies to virions, thus preventing virus entry. However, antibodies that broadly neutralize HIV-1 are rare and are not induced by current vaccines. We report that four human anti-phospholipid monoclonal antibodies (mAbs) (PGN632, P1, IS4, and CL1) inhibit HIV-1 CCR5-tropic (R5) primary isolate infection of peripheral blood mononuclear cells (PBMCs) with 80% inhibitory concentrations of <0.02 to ∼10 µg/ml. Anti-phospholipid mAbs inhibited PBMC HIV-1 infection in vitro by mechanisms involving binding to monocytes and triggering the release of MIP-1α and MIP-1β. The release of these β-chemokines explains both the specificity for R5 HIV-1 and the activity of these mAbs in PBMC cultures containing both primary lymphocytes and monocytes.

scholarly journals A human monoclonal antibody drug and target discovery platform for B-cell chronic lymphocytic leukemia based on allogeneic hematopoietic stem cell transplantation and phage display

Blood ◽  
2009 ◽  
Vol 114 (20) ◽  
pp. 4494-4502 ◽  
Author(s):  
Sivasubramanian Baskar ◽  
Jessica M. Suschak ◽  
Ivan Samija ◽  
Ramaprasad Srinivasan ◽  
Richard W. Childs ◽  
...  
Keyword(s):  
Cell Surface ◽  
Mononuclear Cells ◽  
Surface Antigens ◽  
Lymphocytic Leukemia ◽  
Human Monoclonal Antibodies ◽  
Cell Surface Antigens ◽  
Peripheral Blood Mononuclear ◽  
Hematopoietic Stem ◽  
Antibody Repertoires ◽  
Cell Chronic Lymphocytic Leukemia

Abstract Allogeneic hematopoietic stem cell transplantation (alloHSCT) is the only potentially curative treatment available for patients with B-cell chronic lymphocytic leukemia (B-CLL). Here, we show that post-alloHSCT antibody repertoires can be mined for the discovery of fully human monoclonal antibodies to B-CLL cell-surface antigens. Sera collected from B-CLL patients at defined times after alloHSCT showed selective binding to primary B-CLL cells. Pre-alloHSCT sera, donor sera, and control sera were negative. To identify post-alloHSCT serum antibodies and subsequently B-CLL cell-surface antigens they recognize, we generated a human antibody-binding fragment (Fab) library from post-alloHSCT peripheral blood mononuclear cells and selected it on primary B-CLL cells by phage display. A panel of Fab with B-CLL cell-surface reactivity was strongly enriched. Selection was dominated by highly homologous Fab predicted to bind the same antigen. One Fab was converted to immunoglobulin G1 and analyzed for reactivity with peripheral blood mononuclear cells from B-CLL patients and healthy volunteers. Cell-surface antigen expression was restricted to primary B cells and up-regulated in primary B-CLL cells. Mining post-alloHSCT antibody repertoires offers a novel route to discover fully human monoclonal antibodies and identify antigens of potential therapeutic relevance to B-CLL and possibly other cancers. Trials described herein were registered at www.clinicaltrials.gov as nos. NCT00055744 and NCT00003838.

scholarly journals Comparative kinetics of SARS-CoV-2 anti-spike protein RBD IgGs and neutralizing antibodies in convalescent and naïve recipients of the BNT162b2 mRNA vaccine versus COVID-19 patients

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ioannis P. Trougakos ◽  
Evangelos Terpos ◽  
Christina Zirou ◽  
Aimilia D. Sklirou ◽  
Filia Apostolakou ◽  
...  
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Natural Infection ◽  
Severe Disease ◽  
Vaccination Campaign ◽  
Hospitalized Patients ◽  
Peripheral Blood Mononuclear ◽  
Post Vaccination ◽  
Antibody Titers

Abstract Background Coronavirus SARS-CoV-2, the causative agent of COVID-19, has caused a still evolving global pandemic. Given the worldwide vaccination campaign, the understanding of the vaccine-induced versus COVID-19-induced immunity will contribute to adjusting vaccine dosing strategies and speeding-up vaccination efforts. Methods Anti-spike-RBD IgGs and neutralizing antibodies (NAbs) titers were measured in BNT162b2 mRNA vaccinated participants (n = 250); we also investigated humoral and cellular immune responses in vaccinated individuals (n = 21) of this cohort 5 months post-vaccination and assayed NAbs levels in COVID-19 hospitalized patients (n = 60) with moderate or severe disease, as well as in COVID-19 recovered patients (n = 34). Results We found that one (boosting) dose of the BNT162b2 vaccine triggers robust immune (i.e., anti-spike-RBD IgGs and NAbs) responses in COVID-19 convalescent healthy recipients, while naïve recipients require both priming and boosting shots to acquire high antibody titers. Severe COVID-19 triggers an earlier and more intense (versus moderate disease) immune response in hospitalized patients; in all cases, however, antibody titers remain at high levels in COVID-19 recovered patients. Although virus infection promotes an earlier and more intense, versus priming vaccination, immune response, boosting vaccination induces antibody titers significantly higher and likely more durable versus COVID-19. In support, high anti-spike-RBD IgGs/NAbs titers along with spike (vaccine encoded antigen) specific T cell clones were found in the serum and peripheral blood mononuclear cells, respectively, of vaccinated individuals 5 months post-vaccination. Conclusions These findings support vaccination efficacy, also suggesting that vaccination likely offers more protection than natural infection. Graphical abstract

scholarly journals Comprehensive investigations revealed consistent pathophysiological alterations after vaccination with COVID-19 vaccines

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiping Liu ◽  
Junbang Wang ◽  
Jinfang Xu ◽  
Han Xia ◽  
Yue Wang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Large Scale ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Cell Types ◽  
Type I ◽  
Peripheral Blood Mononuclear ◽  
Biological Assays ◽  
Clinical Conditions ◽  
Interferon Responses

AbstractLarge-scale COVID-19 vaccinations are currently underway in many countries in response to the COVID-19 pandemic. Here, we report, besides generation of neutralizing antibodies, consistent alterations in hemoglobin A1c, serum sodium and potassium levels, coagulation profiles, and renal functions in healthy volunteers after vaccination with an inactivated SARS-CoV-2 vaccine. Similar changes had also been reported in COVID-19 patients, suggesting that vaccination mimicked an infection. Single-cell mRNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) before and 28 days after the first inoculation also revealed consistent alterations in gene expression of many different immune cell types. Reduction of CD8+ T cells and increase in classic monocyte contents were exemplary. Moreover, scRNA-seq revealed increased NF-κB signaling and reduced type I interferon responses, which were confirmed by biological assays and also had been reported to occur after SARS-CoV-2 infection with aggravating symptoms. Altogether, our study recommends additional caution when vaccinating people with pre-existing clinical conditions, including diabetes, electrolyte imbalances, renal dysfunction, and coagulation disorders.

scholarly journals Borrelia burgdorferi-Induced Tolerance as a Model of Persistence via Immunosuppression

2003 ◽  
Vol 71 (7) ◽  
pp. 3979-3987 ◽  
Author(s):  
Isabel Diterich ◽  
Carolin Rauter ◽  
Carsten J. Kirschning ◽  
Thomas Hartung
Keyword(s):  
Borrelia Burgdorferi ◽  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Bone Marrow Cells ◽  
Mrna Levels ◽  
Blood Monocytes ◽  
Cross Tolerance ◽  
Tlr2 Expression ◽  
Peripheral Blood Mononuclear ◽  
Tlr4 Mrna

ABSTRACT If left untreated, infection with Borrelia burgdorferi sensu lato may lead to chronic Lyme borreliosis. It is still unknown how this pathogen manages to persist in the host in the presence of competent immune cells. It was recently reported that Borrelia suppresses the host's immune response, thus perhaps preventing the elimination of the pathogen (I. Diterich, L. Härter, D. Hassler, A. Wendel, and T. Hartung, Infect. Immun. 69:687-694, 2001). Here, we further characterize Borrelia-induced immunomodulation in order to develop a model of this anergy. We observed that the different Borrelia preparations that we tested, i.e., live, heat-inactivated, and sonicated Borrelia, could desensitize human blood monocytes, as shown by attenuated cytokine release upon restimulation with any of the different preparations. Next, we investigated whether these Borrelia-specific stimuli render monocytes tolerant, i.e. hyporesponsive, towards another Toll-like receptor 2 (TLR2) agonist, such as lipoteichoic acid from gram-positive bacteria, or towards the TLR4 agonist lipopolysaccharide. Cross-tolerance towards all tested stimuli was induced. Furthermore, using primary bone marrow cells from TLR2-deficient mice and from mice with a nonfunctional TLR4 (strain C3H/HeJ), we demonstrated that the TLR2 was required for tolerance induction by Borrelia, and using neutralizing antibodies, we identified interleukin-10 as the key mediator involved. Although peripheral blood mononuclear cells tolerized by Borrelia exhibited reduced TLR2 and TLR4 mRNA levels, the expression of the respective proteins on monocytes was not decreased, ruling out the possibility that tolerance to Borrelia is attributed to a reduced TLR2 expression. In summary, we characterized tolerance induced by B. burgdorferi, describing a model of desensitization which might mirror the immunosuppression recently attributed to the persistence of Borrelia in immunocompetent hosts.

SOSIP trimer-specific antibodies isolated from a SHIV-infected monkey with versus without a pre-blocking step with gp41

2021 ◽  
Author(s):  
Natasha N. Duggan ◽  
Kim L. Weisgrau ◽  
Diogo M. Magnani ◽  
Eva G. Rakasz ◽  
Ronald C. Desrosiers ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Broadly Neutralizing Antibodies ◽  
Peripheral Blood Mononuclear ◽  
Specific Antibodies ◽  
Neutralizing Activity ◽  
Infected Monkey ◽  
External Domain ◽  
Hiv 1

BG505 SOSIP.664 (hereafter referred to as SOSIP), a stabilized trimeric mimic of the HIV-1 envelope spike resembling the native viral spike, is a useful tool for isolating anti-HIV-1 neutralizing antibodies. We screened long-term SHIV-AD8 infected rhesus monkeys for potency and breadth of serum neutralizing activity against autologous and heterologous viruses: SHIV-AD8, HIV-1 YU2, HIV-1 JR-CSF, and HIV-1 NL4-3. Monkey rh2436 neutralized all viruses tested and showed strong reactivity to the SOSIP trimer, suggesting this was a promising candidate for attempts at monoclonal antibody (mAb) isolation. Monoclonal antibodies were isolated by performing single B-cell sorts from peripheral blood mononuclear cells (PBMC) by FACS using the SOSIP trimer as a probe. An initial round of sorted cells revealed the majority of isolated mAbs were directed to the gp41 external domain portion of the SOSIP trimer and were mostly non-neutralizing against tested isolates. A second sort was performed, introducing a gp41 blocking step prior to PBMC staining and FACS sorting. These isolated mAbs bound SOSIP trimer but were no longer directed to the gp41 external domain portion. A significantly higher proportion of mAbs with neutralizing activity were obtained with this strategy. Our data show this pre-blocking step with gp41 greatly increases the yield of non-gp41 reactive, SOSIP- specific mAbs and increases the likelihood of isolating mAbs with neutralizing activity. Importance Recent advancements in the field have focused on the isolation and use of broadly neutralizing antibodies for both prophylaxis and therapy. Finding a useful probe to isolate broad potent neutralizing antibodies while avoiding non-neutralizing antibodies is important. The SOSIP trimer has been shown to be a great tool for this purpose because it binds known broadly neutralizing antibodies. However, the SOSIP trimer can isolate non-neutralizing antibodies as well, including gp41-specific mAbs. Introducing a pre-blocking step with gp41 recombinant protein decreased the percent of gp41-specific antibodies isolated with SOSIP probe, as well as increased the number of neutralizing antibodies isolated. This method could be used as a tool to increase the chances of isolating neutralizing antibodies.

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