scholarly journals Association of human cytomegalovirus (HCMV) neutralizing antibodies with antibodies to the HCMV glycoprotein complexes

2020 ◽  
Author(s):  
Miho Shibamura ◽  
Tomoki Yoshikawa ◽  
Souichi Yamada ◽  
Takuya Inagaki ◽  
Phu Hoang Anh Nguyen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Cytomegalovirus ◽  
Neutralizing Antibodies ◽  
Immunofluorescence Assay ◽  
Plaque Reduction Assay ◽  
Glycoprotein Complex ◽  
Life Threatening ◽  
Antibody Titers ◽  
Asymptomatic Infections ◽  
Adult Volunteers

Abstract Background: Human cytomegalovirus (HCMV) causes asymptomatic infections, but also causes congenital infections when women were infected with HCMV during pregnancy, and life-threatening diseases in immunocompromised patients. To better understand the mechanism of the neutralization activity against HCMV, the association of HCMV NT antibody titers was assessed with the antibody titers against each glycoprotein complex (gc) of HCMV. Methods: Sera collected from 78 healthy adult volunteers were used. HCMV Merlin strain and HCMV clinical isolate strain 1612 were used in the NT assay with the plaque reduction assay, in which both the MRC-5 fibroblasts cells and the RPE-1 epithelial cells were used. Glycoprotein complex of gB, gH/gL complexes (gH/gL/gO and gH/gL/UL128-131A [PC]) and gM/gN were selected as target glycoproteins. 293FT cells expressed with gB, gM/gN, gH/gL/gO, or PC, were prepared and used for the measurement of the antibody titers against each gc in an indirect immunofluorescence assay (IIFA). The correlation between the IIFA titers to each gc and the HCMV-NT titers was evaluated.Results: There were no significant correlations between gB-specific IIFA titers and the HCMV-NT titers in epithelial cells or between gM/gN complex-specific IIFA titers and the HCMV-NT titers. On the other hand, there was a statistically significant positive correlation between the IIFA titers to gH/gL complexes and HCMV-NT titers.Conclusions: The data suggest that the gH/gL complexes might be the major target to induce NT activity against HCMV.

scholarly journals Association of human cytomegalovirus (HCMV) neutralizing antibodies with antibodies to the HCMV glycoprotein complexes

2020 ◽  
Author(s):  
Miho Shibamura ◽  
Tomoki Yoshikawa ◽  
Souichi Yamada ◽  
Takuya Inagaki ◽  
Phu Hoang Anh Nguyen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Cytomegalovirus ◽  
Neutralizing Antibodies ◽  
Immunofluorescence Assay ◽  
Plaque Reduction Assay ◽  
Glycoprotein Complex ◽  
Life Threatening ◽  
Antibody Titers ◽  
Asymptomatic Infections ◽  
Adult Volunteers

Abstract Background Human cytomegalovirus (HCMV) causes asymptomatic infections, but also causes congenital infections when women were infected with HCMV during pregnancy, and life-threatening diseases in immunocompromised patients. To better understand the mechanism of the neutralization activity against HCMV, the association of HCMV NT antibody titers was assessed with the antibody titers against each glycoprotein complex (gc) of HCMV. Methods Sera collected from 78 healthy adult volunteers were used. HCMV Merlin strain and HCMV clinical isolate strain 1612 were used in the NT assay with the plaque reduction assay, in which both the MRC-5 fibroblasts cells and the RPE-1 epithelial cells were used. Glycoprotein complex of gB, gH/gL complexes (gH/gL/gO and gH/gL/UL128-131A [PC]) and gM/gN were selected as target glycoproteins. 293FT cells expressed with gB, gM/gN, gH/gL/gO, or PC, were prepared and used for the measurement of the antibody titers against each gc in an indirect immunofluorescence assay (IIFA). The correlation between the IIFA titers to each gc and the HCMV-NT titers was evaluated. Results There were no significant correlations between gB-specific IIFA titers and the HCMV-NT titers in epithelial cells or between gM/gN complex-specific IIFA titers and the HCMV-NT titers. On the other hand, there was a statistically significant positive correlation between the IIFA titers to gH/gL complexes and HCMV-NT titers. Conclusions The data suggest that the gH/gL complexes might be the major target to induce NT activity against HCMV.

scholarly journals Human cytomegalovirus serum neutralizing antibodies block virus infection of endothelial/epithelial cells, but not fibroblasts, early during primary infection

2008 ◽  
Vol 89 (4) ◽  
pp. 853-865 ◽  
Author(s):  
Giuseppe Gerna ◽  
Antonella Sarasini ◽  
Marco Patrone ◽  
Elena Percivalle ◽  
Loretta Fiorina ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Cytomegalovirus ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Human Fibroblasts ◽  
Cell Infection ◽  
Neutralizing Activity ◽  
Hyperimmune Globulin ◽  
Human Sera ◽  
Infected Cells

A panel of human sera exhibited a ≥128-fold higher neutralizing potency against a human cytomegalovirus (HCMV) clinical isolate propagated and tested in endothelial (or epithelial) cells than against the same virus infecting human fibroblasts. In a group of 18 primary infections, the reverse geometric mean titre was in the range of 10–15 in human fibroblasts within the first 3 months after the onset of infection, whereas the endothelial cell infection-neutralizing activity was already present within the first 10 days, reaching median levels of 122, 320 and 545 at respectively 30, 60 and 90 days after onset, then declining slowly. This difference was also confirmed in the majority of reactivated and remote HCMV infections, as well as in a hyperimmune globulin preparation. The antibody response to HCMV pUL131A, pUL130 and pUL128 locus products, which are required for endothelial/epithelial cell infection, provided a potential molecular basis for such a differential neutralizing activity. In addition, monoclonal/monospecific antibodies raised against the pUL131A, pUL130 and pUL128 proteins were found to display an inhibitory activity on HCMV plaque formation and HCMV leukocyte transfer from HCMV-infected cells. Hence, conventional determination of the neutralizing activity of human sera in fibroblasts is misleading. Antibodies to pUL131A, pUL130 and pUL128 appear to display a major HCMV-neutralizing and dissemination-inhibiting activity.

scholarly journals OR14I1 is a receptor for the human cytomegalovirus pentameric complex and defines viral epithelial cell tropism

2019 ◽  
Vol 116 (14) ◽  
pp. 7043-7052 ◽  
Author(s):  
Xiaofei E ◽  
Paul Meraner ◽  
Ping Lu ◽  
Jill M. Perreira ◽  
Aaron M. Aker ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Adenylate Cyclase ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Cell Types ◽  
Akt Activation ◽  
Antiviral Therapies ◽  
Glycoprotein Complex ◽  
Genome Wide ◽  
Different Cell Types

A human cytomegalovirus (HCMV) pentameric glycoprotein complex (PC), gH–gL–UL128–UL130–UL131A, is necessary for viral infection of clinically relevant cell types, including epithelial cells, which are important for interhost transmission and disease. We performed genome-wide CRISPR/Cas9 screens of different cell types in parallel to identify host genes specifically required for HCMV infection of epithelial cells. This effort identified a multipass membrane protein, OR14I1, as a receptor for HCMV infection. This olfactory receptor family member is required for HCMV attachment, entry, and infection of epithelial cells and is dependent on the presence of viral PC. OR14I1 is required for AKT activation and mediates endocytosis entry of HCMV. We further found that HCMV infection of epithelial cells is blocked by a synthetic OR14I1 peptide and inhibitors of adenylate cyclase and protein kinase A (PKA) signaling. Identification of OR14I1 as a PC-dependent HCMV host receptor associated with epithelial tropism and the role of the adenylate cyclase/PKA/AKT–mediated signaling pathway in HCMV infection reveal previously unappreciated targets for the development of vaccines and antiviral therapies.

scholarly journals Immunization with Epstein–Barr Virus Core Fusion Machinery Envelope Proteins Elicit High Titers of Neutralizing Activities and Protect Humanized Mice from Lethal Dose EBV Challenge

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 285
Author(s):  
Xinle Cui ◽  
Zhouhong Cao ◽  
Yuriko Ishikawa ◽  
Sara Cui ◽  
Ken-Ichi Imadome ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
B Lymphocytes ◽  
Neutralizing Antibodies ◽  
Epstein Barr Virus ◽  
Lethal Dose ◽  
Envelope Proteins ◽  
Humanized Mice ◽  
Target Cells ◽  
Barr Virus ◽  
Epstein Barr

Epstein–Barr virus (EBV) is the primary cause of infectious mononucleosis and is strongly implicated in the etiology of multiple lymphoid and epithelial cancers. EBV core fusion machinery envelope proteins gH/gL and gB coordinately mediate EBV fusion and entry into its target cells, B lymphocytes and epithelial cells, suggesting these proteins could induce antibodies that prevent EBV infection. We previously reported that the immunization of rabbits with recombinant EBV gH/gL or trimeric gB each induced markedly higher serum EBV-neutralizing titers for B lymphocytes than that of the leading EBV vaccine candidate gp350. In this study, we demonstrated that immunization of rabbits with EBV core fusion machinery proteins induced high titer EBV neutralizing antibodies for both B lymphocytes and epithelial cells, and EBV gH/gL in combination with EBV trimeric gB elicited strong synergistic EBV neutralizing activities. Furthermore, the immune sera from rabbits immunized with EBV gH/gL or trimeric gB demonstrated strong passive immune protection of humanized mice from lethal dose EBV challenge, partially or completely prevented death respectively, and markedly decreased the EBV load in peripheral blood of humanized mice. These data strongly suggest the combination of EBV core fusion machinery envelope proteins gH/gL and trimeric gB is a promising EBV prophylactic vaccine.

scholarly journals Convalescent Plasma Efficacy in Life-Threatening COVID-19 Patients Admitted to the ICU: A Retrospective Cohort Study

2021 ◽  
Vol 10 (10) ◽  
pp. 2113
Author(s):  
Mohamed Abuzakouk ◽  
Khaled Saleh ◽  
Manuel Algora ◽  
Ahmad Nusair ◽  
Jawahir Alameri ◽  
...  
Keyword(s):  
Hospital Mortality ◽  
Clinical Improvement ◽  
Primary Outcome ◽  
Neutralizing Antibody ◽  
Limited Data ◽  
Inverse Probability Weights ◽  
Single Center Study ◽  
Life Threatening ◽  
Antibody Titers ◽  
Disease Severity Scale

(1) Background: There are limited data regarding the efficacy of convalescent plasma (CP) in critically ill patients admitted to the intensive care unit (ICU) due to coronavirus disease 2019 (COVID-19). We aimed to determine whether CP is associated with better clinical outcome among these patients. (2) Methods: A retrospective single-center study including adult patients with laboratory-confirmed SARS-CoV-2 infection admitted to the ICU for acute respiratory failure. The primary outcome was time to clinical improvement, within 28 days, defined as patient discharged alive or reduction of 2 points on a 6-point disease severity scale. (3) Results: Overall, 110 COVID-19 patients were admitted. Thirty-two patients (29%) received CP; among them, 62.5% received at least one CP with high neutralizing antibody titers (≥1:160). Clinical improvement occurred within 28 days in 14 patients (43.7%) of the CP group vs. 48 patients (61.5%) in the non-CP group (hazard ratio (HR): 0.75 (95% CI: 0.41–1.37), p = 0.35). After adjusting for potential confounding factors, CP was not independently associated with time to clinical improvement (HR: 0.53 (95% CI: 0.23–1.22), p = 0.14). Additionally, the average treatment effects of CP, calculated using the inverse probability weights (IPW), was not associated with the primary outcome (−0.14 days (95% CI: −3.19–2.91 days), p = 0.93). Hospital mortality did not differ between CP and non-CP groups (31.2% vs. 19.2%, p = 0.17, respectively). Comparing CP with high neutralizing antibody titers to the other group yielded the same findings. (4) Conclusions: In this study of life-threatening COVID-19 patients, CP was not associated with time to clinical improvement within 28 days, or hospital mortality.

scholarly journals Genome sequences of human cytomegalovirus strain TB40/E variants propagated in fibroblasts and epithelial cells

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Ahmed Al Qaffas ◽  
Salvatore Camiolo ◽  
Mai Vo ◽  
Alexis Aguiar ◽  
Amine Ourahmane ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Cytomegalovirus ◽  
Viral Entry ◽  
Sequence Data ◽  
Laboratory Strain ◽  
Serial Passage ◽  
Wild Type Virus ◽  
Protein Coding ◽  
Genetic Changes ◽  
Long Read

AbstractThe advent of whole genome sequencing has revealed that common laboratory strains of human cytomegalovirus (HCMV) have major genetic deficiencies resulting from serial passage in fibroblasts. In particular, tropism for epithelial and endothelial cells is lost due to mutations disrupting genes UL128, UL130, or UL131A, which encode subunits of a virion-associated pentameric complex (PC) important for viral entry into these cells but not for entry into fibroblasts. The endothelial cell-adapted strain TB40/E has a relatively intact genome and has emerged as a laboratory strain that closely resembles wild-type virus. However, several heterogeneous TB40/E stocks and cloned variants exist that display a range of sequence and tropism properties. Here, we report the use of PacBio sequencing to elucidate the genetic changes that occurred, both at the consensus level and within subpopulations, upon passaging a TB40/E stock on ARPE-19 epithelial cells. The long-read data also facilitated examination of the linkage between mutations. Consistent with inefficient ARPE-19 cell entry, at least 83% of viral genomes present before adaptation contained changes impacting PC subunits. In contrast, and consistent with the importance of the PC for entry into endothelial and epithelial cells, genomes after adaptation lacked these or additional mutations impacting PC subunits. The sequence data also revealed six single noncoding substitutions in the inverted repeat regions, single nonsynonymous substitutions in genes UL26, UL69, US28, and UL122, and a frameshift truncating gene UL141. Among the changes affecting protein-coding regions, only the one in UL122 was strongly selected. This change, resulting in a D390H substitution in the encoded protein IE2, has been previously implicated in rendering another viral protein, UL84, essential for viral replication in fibroblasts. This finding suggests that IE2, and perhaps its interactions with UL84, have important functions unique to HCMV replication in epithelial cells.

scholarly journals Development of a Vaccine against Human Cytomegalovirus: Advances, Barriers, and Implications for the Clinical Practice

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 551
Author(s):  
Sara Scarpini ◽  
Francesca Morigi ◽  
Ludovica Betti ◽  
Arianna Dondi ◽  
Carlotta Biagi ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Human Cytomegalovirus ◽  
Congenital Infection ◽  
Health Concern ◽  
Live Vaccines ◽  
Target Populations ◽  
Immune Correlates ◽  
Common Causes ◽  
The Status ◽  
Life Threatening

Human cytomegalovirus (hCMV) is one of the most common causes of congenital infection in the post-rubella era, representing a major public health concern. Although most cases are asymptomatic in the neonatal period, congenital CMV (cCMV) disease can result in permanent impairment of cognitive development and represents the leading cause of non-genetic sensorineural hearing loss. Moreover, even if hCMV mostly causes asymptomatic or pauci-symptomatic infections in immunocompetent hosts, it may lead to severe and life-threatening disease in immunocompromised patients. Since immunity reduces the severity of disease, in the last years, the development of an effective and safe hCMV vaccine has been of great interest to pharmacologic researchers. Both hCMV live vaccines—e.g., live-attenuated, chimeric, viral-based—and non-living ones—subunit, RNA-based, virus-like particles, plasmid-based DNA—have been investigated. Encouraging data are emerging from clinical trials, but a hCMV vaccine has not been licensed yet. Major difficulties in the development of a satisfactory vaccine include hCMV’s capacity to evade the immune response, unclear immune correlates for protection, low number of available animal models, and insufficient general awareness. Moreover, there is a need to determine which may be the best target populations for vaccine administration. The aim of the present paper is to examine the status of hCMV vaccines undergoing clinical trials and understand barriers limiting their development.

scholarly journals Seroprevalence and correlates of SARS-CoV-2 neutralizing antibodies from a population-based study in Bonn, Germany

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
N. Ahmad Aziz ◽  
Victor M. Corman ◽  
Antje K. C. Echterhoff ◽  
Marcel A. Müller ◽  
Anja Richter ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Response Rate ◽  
Neutralization Test ◽  
Population Based ◽  
Immunofluorescence Assay ◽  
Test Results ◽  
Community Based ◽  
Population Based Study ◽  
Temporal Course ◽  
Confirmatory Tests

AbstractTo estimate the seroprevalence and temporal course of SARS-CoV-2 neutralizing antibodies, we embedded a multi-tiered seroprevalence survey within an ongoing community-based cohort study in Bonn, Germany. We first assessed anti-SARS-CoV-2 immunoglobulin G levels with an immunoassay, followed by confirmatory testing of borderline and positive test results with a recombinant spike-based immunofluorescence assay and a plaque reduction neutralization test (PRNT). Those with a borderline or positive immunoassay result were retested after 4 to 5 months. At baseline, 4771 persons participated (88% response rate). Between April 24th and June 30th, 2020, seroprevalence was 0.97% (95% CI: 0.72−1.30) by immunoassay and 0.36% (95% CI: 0.21−0.61) when considering only those with two additional positive confirmatory tests. Importantly, about 20% of PRNT+ individuals lost their neutralizing antibodies within five months. Here, we show that neutralizing antibodies are detectable in only one third of those with a positive immunoassay result, and wane relatively quickly.

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