Piet MaesKU Leuven | ku leuven · Department of Microbiology and Immunology
Piet Maes
Ph.D. Medical Sciences
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393
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Introduction
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December 2012 - present
March 2001 - present
Publications
Publications (393)
The emergence of SARS-CoV-2 variants escaping immunity challenges the efficacy of current vaccines. Here, we investigated humoral recall responses and vaccine-mediated protection in Syrian hamsters immunized with the third-generation Comirnaty® Omicron XBB.1.5-adapted COVID-19 mRNA vaccine, followed by infection with either antigenically closely (E...
We investigate the emergence, mutation profile, and dissemination of SARS-CoV-2 lineage B.1.214.2, first identified in Belgium in January 2021. This variant, featuring a 3-amino acid insertion in the spike protein similar to the Omicron variant, was speculated to enhance transmissibility or immune evasion. Initially detected in international travel...
Background
Cytomegalovirus (CMV) infection poses a significant risk to immunosuppressed transplant recipients, manifesting through primary infection, reinfection, or reactivation.
Methods
We analyzed the emergence of drug resistance in CMV infection in 3 patients who were later found to have received an allograft from a shared, deceased donor. The...
In 2022 the WHO declared the worldwide outbreak of mpox to be a public health emergency of international concern (PHEIC). The causative monkeypox virus (MPXV) belonged to Clade IIb and transmitted through sexual contact with a low case fatality rate (0.1%), which together with underdetection, all contributed to a rapid global spread particularly wi...
Prior to 2017, the family Bunyaviridae included five genera of arthropod and rodent viruses with tri-segmented negative-sense RNA genomes related to the Bunyamwera virus. In 2017, the International Committee on Taxonomy of Viruses (ICTV) promoted the family to order Bunyavirales and subsequently greatly expanded its composition by adding multiple f...
The approval of COVID-19 vaccines and two classes of antiviral drugs has been crucial in addressing the global health crisis caused by SARS-CoV-2. However, to prepare for future outbreaks from drug-resistant variants and novel zoonotic coronaviruses (CoVs), additional therapeutics with a distinct antiviral mechanism are needed. Here, we report a no...
Understanding the evolution of the B cell response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants is fundamental to design the next generation of vaccines and therapeutics. We longitudinally analyze at the single-cell level almost 900 neutralizing human monoclonal antibodies (nAbs) isolated from vaccinated people and from...
We investigate the emergence, mutation profile, and dissemination of SARS-CoV-2 lineage B.1.214.2, first identified in Belgium in January 2021. This variant, featuring a 3-amino acid insertion in the spike protein similar to the Omicron variant, was speculated to enhance transmissibility or immune evasion. Initially detected in international travel...
Several inflammatory diseases are characterized by a disruption in the equilibrium between the host and its microbiome. Due to the increase in resistance, the use of antibiotics for the widespread, nonspecific killing of microorganisms is at risk. Pro-microbial approaches focused on stimulating or introducing beneficial species antagonistic toward...
Hantaviridae is a family for negative-sense RNA viruses with genomes of about 10.5-14.6 kb. These viruses are maintained in and/or transmitted by fish, reptiles, and mammals. Several orthohantaviruses can infect humans, causing mild, severe, and sometimes-fatal diseases. Hantavirids produce enveloped virions containing three single-stranded RNA seg...
The unceasing interplay between SARS-CoV-2 and the human immune system has led to a continuous maturation of the virus and B cell response providing an opportunity to track their evolution in real time. We longitudinally analyzed the functional activity of almost 1,000 neutralizing human monoclonal antibodies (nAbs) isolated from vaccinated people,...
Since the onset of the coronavirus disease (COVID-19) pandemic in Belgium, UZ/KU Leuven has played a crucial role as the National Reference Centre (NRC) for respiratory pathogens, to be the first Belgian laboratory to develop and implement laboratory developed diagnostic assays for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and la...
Infection by hepatitis B virus (HBV) is responsible for approximately 296 million chronic cases of hepatitis B, and roughly 880,000 deaths annually. The global burden of HBV is distributed unevenly, largely owing to the heterogeneous geographic distribution of its subtypes, each of which demonstrates different severity and responsiveness to antivir...
With an estimated 65 million individuals suffering from Long COVID, validated therapeutic strategies as well as non-invasive biomarkers are direly needed to guide clinical management. We used blood digital transcriptomics in search of viral persistence and Long COVID diagnostic biomarkers in a real-world, general practice-based setting with a long...
Metagenomics is gradually being implemented for diagnosing infectious diseases. However, in-depth protocol comparisons for viral detection have been limited to individual sets of experimental workflows and laboratories. In this study, we present a benchmark of metagenomics protocols used in clinical diagnostic laboratories initiated by the European...
Since the emergence of the first omicron SARS-CoV-2 variant at the end of 2021, several sub-variants have evolved and become predominant in the human population, showing enhanced transmissibility and ability to (partly) escape the adaptive immune response. The XBB sub-variants (e.g., EG.5.1) have become globally dominant. Besides the XBB sub-varian...
Cruliviridae is a family of negative-sense RNA viruses with genomes of 10.8–11.5 kb that have been found in crustaceans. The crulivirid genome consists of three RNA segments with ORFs that encode a nucleoprotein (NP), a glycoprotein (GP), a large (L) protein containing an RNA-directed RNA polymerase (RdRP) domain, and in some family members, a zinc...
Tulasviridae is a family of ambisense RNA viruses with genomes of about 12.2 kb that have been found in fungi. The tulasvirid genome is nonsegmented and contains three open reading frames (ORFs) that encode a nucleoprotein (NP), a large (L) protein containing an RNA-directed RNA polymerase (RdRP) domain, and a protein of unknown function (X). This...
Wupedeviridae is a family of negative-sense RNA viruses with genomes of about 20.5 kb that have been found in myriapods. The wupedevirid genome consists of three monocistronic RNA segments with open reading frames (ORFs) that encode a nucleoprotein (NP), a glycoprotein (GP), and a large (L) protein containing an RNA-directed RNA polymerase (RdRP) d...
Mypoviridae is a family of negative-sense RNA viruses with genomes of about 16.0 kb that have been found in myriapods. The mypovirid genome consists of three monocistronic RNA segments that encode a nucleoprotein (NP), a glycoprotein (GP), and a large (L) protein containing an RNA-directed RNA polymerase (RdRP) domain. This is a summary of the Inte...
Public holidays have been associated with SARS-CoV-2 incidence surges, although a firm link remains to be established. This association is sometimes attributed to events where transmissions occur at a disproportionately high rate, known as superspreading events. Here, we describe a sudden surge in new cases with the Omicron BA.1 strain amongst high...
Leishbuviridae is a family of negative-sense RNA viruses with genomes of about 8.0 kb that have been found in protists. The leishbuvirid genome consists of three monocistronic RNA segments with open reading frames (ORFs) that encode a nucleoprotein (NP), a glycoprotein (GP), and a large (L) protein containing an RNA-directed RNA polymerase (RdRP) d...
Discoviridae is a family of negative-sense RNA viruses with genomes of 6.2-9.7 kb that have been associated with fungi and stramenopiles. The discovirid genome consists of three monocistronic RNA segments with open reading frames (ORFs) that encode a nucleoprotein (NP), a nonstructural protein (Ns), and a large (L) protein containing an RNA-directe...
In the future, zoonotic spillover events are expected to happen more frequently. Consequences of such events have clearly been demonstrated by recent outbreaks of monkeypox, Ebola virus and the well-known SARS-CoV-2. Virus discovery has proven to be an important tool in the preparation against viral outbreaks, generating data concerning diversity,...
Background
The earliest recognised infections by the SARS-CoV-2 Omicron variant (Pango lineage B.1.1.529) in Belgium and Switzerland suggested a connection to an international water polo tournament, held 12–14 November 2021 in Brno, Czechia.
Aim
To study the arrival and subsequent spread of the Omicron variant in Belgium and Switzerland, and under...
Background
To support the COVID‐19 pandemic response, many countries, including Belgium, implemented baseline genomic surveillance (BGS) programs aiming to early detect and characterize new SARS‐CoV‐2 variants. In parallel, Belgium maintained a sentinel network of six hospitals that samples patients with severe acute respiratory infections (SARI) a...
In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished...
Mpox is a viral zoonosis with endemic circulation in animals and humans in some West and Central African countries. The disease was imported a few times in the past to countries outside the African continent through infected animals or travelers, one of which resulted in an unprecedented global outbreak sustained by human-to-human transmission in 2...
SARS-CoV-2 is associated with broad tissue tropism, a characteristic often determined by the availability of entry receptors on host cells. Here, we show that TMEM106B, a lysosomal transmembrane protein, can serve as an alternative receptor for SARS-CoV-2 entry into angiotensin-converting enzyme 2 (ACE2)-negative cells. Spike substitution E484D inc...
In the search for natural reservoirs of hepatitis C virus (HCV), a broad diversity of non-human viruses within the Hepacivirus genus has been uncovered. However, the evolutionary dynamics that shaped the diversity and timescale of hepaciviruses evolution remain elusive. To gain further insights into the origins and evolution of this genus, we scree...
In the search for natural reservoirs of hepatitis C virus (HCV), a broad diversity of non-human viruses within the Hepacivirus genus has been uncovered. However, the evolutionary dynamics that shaped the diversity and timescale of hepaciviruses evolution remain elusive. To gain further insights into the origins and evolution of this genus, we scree...
Infection with bovine papillomavirus (BPV) types 1 and 2 results in the most common skin tumor of horses, termed equine sarcoid. The persistent and recurrent nature of this tumor stands in contrast to the regressive nature of BPV-1/-2 induced cutaneous papillomas in cattle. The circulation of horse-specific BPV-1/-2 variants within equine populatio...
Introduction:
Herpesviruses are a widespread family of double-stranded DNA viruses that establish life-long persistent infection in their hosts. Cumulative evidence tends to argue for the association of human herpesviruses, such as Kaposi's sarcoma herpesvirus (KHSV), Epstein-Barr virus (EBV), and human cytomegalovirus (HCMV) with various human di...
Coronavirus Disease 2019 (COVID-19) vaccination has resulted in excellent protection against fatal disease, including in older adults. However, risk factors for post-vaccination fatal COVID-19 are largely unknown. We comprehensively studied three large nursing home outbreaks (20-35% fatal cases among residents) by combining severe acute respiratory...
Severe acute respiratory syndrome 2 Omicron BA.4 and BA.5 are characterized by high transmissibility and ability to escape natural and vaccine induced immunity. Here we test the neutralizing activity of 482 human monoclonal antibodies isolated from people who received two or three mRNA vaccine doses or from people vaccinated after infection. The BA...
During cotranslational translocation, the signal peptide of a nascent chain binds Sec61 translocon to initiate protein transport through the endoplasmic reticulum (ER) membrane. Our cryo-electron microscopy structure of ribosome-Sec61 shows binding of an ordered heterotetrameric translocon-associated protein (TRAP) complex, in which TRAP-γ is ancho...
Background
Lateral flow antigen-detection rapid diagnostic tests (Ag-RDTs) for viral infections constitute a fast, cheap and reliable alternative to nucleic acid amplification tests (NAATs). Whereas leftover material from NAATs can be employed for genomic analysis of positive samples, there is a paucity of information on whether viral genetic chara...
The official classification of newly discovered or long-known unassigned viruses by the International Committee on Taxonomy of Viruses (ICTV) requires the deposition of coding-complete or-near-complete virus genome sequences in GenBank to fulfill a requirement of the taxo-nomic proposal (TaxoProp) process. However, this requirement is fairly new; t...
Convergent evolution of SARS-CoV-2 Omicron BA.2, BA.4, and BA.5 lineages has led to the emergence of several new subvariants, including BA.2.75.2, BA.4.6. and BQ.1.1. The subvariant BQ.1.1 became predominant in many countries in December 2022. The subvariants carry an additional and often redundant set of mutations in the spike, likely responsible...
During the last 20 years, numerous new hantaviruses belonging to different species have been discovered in non-rodent micro-mammals. In the following, using the results of a Bayesian analysis, we describe Landiras virus (LDRV), a new Orthohantavirus discovered in a recently described new mole species: Talpa aquitania (Nicolas et al., 2015, 2017). T...
Background
Only two cases of papillomavirus infections in North American porcupines ( Erethizon dorsatum ) have been described thus far, and molecular investigation linked these cases to two distinct papillomavirus species.
Methods
In this report, we present the clinical, histological and molecular investigation of a third case of a porcupine papi...
The SARS-CoV-2 main protease (3CLpro) has an indispensable role in the viral life cycle and is a therapeutic target for the treatment of COVID-19. The potential of 3CLpro-inhibitors to select for drug-resistant variants needs to be established. Therefore, SARS-CoV-2 was passaged in vitro in the presence of increasing concentrations of ALG-097161, a...
During the last 20 years, numerous new hantaviruses belongingto different species have been discovered in non-rodent micro-mammals. In the following, using the results of a Bayesian ana-lysis, we describe Landiras virus (LDRV), a new Orthohantavirus discovered in a recently described new mole species: Talpa aquitania (Nicolas et al. 2015, 2017). Th...
Remdesivir was the first antiviral drug to be approved for the treatment of severe COVID-19; followed by molnupiravir (another prodrug of a nucleoside analogue) and the protease inhibitor nirmatrelvir. Combination of antiviral drugs may result in improved potency and help to avoid or delay the development of resistant variants. We set out to explor...
Public holidays have been associated with SARS-CoV-2 incidence surges, although a firm causal link remains to be established. This association is sometimes attributed to events where transmissions occur at a disproportionately high rate, known as superspreading events. Here, we describe a sudden surge in new cases with the Omicron BA.1 strain among...
Public holidays have been associated with SARS-CoV-2 incidence surges, although a firm causal link remains to be established. This association is sometimes attributed to events where transmissions occur at a disproportionately high rate, known as superspreading events. Here, we describe a sudden surge in new cases with the Omicron BA.1 strain among...
In March 2022, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by two new families (bunyaviral Discoviridae and Tulasviridae), 41 new genera, and 98 new species. Three hundred forty-nine species were renam...
[This corrects the article DOI: 10.3389/fimmu.2022.909910.].
Convergent evolution of SARS-CoV-2 Omicron BA.2, BA.4 and BA.5 lineages has led to the emergence of several new subvariants, including BA.2.75.2, BA.4.6. and BQ.1.1. The subvariants BA.2.75.2 and BQ.1.1 are expected to become predominant in many countries in November 2022. They carry an additional and often redundant set of mutations in the spike,...
Current COVID-19 vaccines are based on prototypic spike sequences from ancestral 2019 SARS-CoV-2 strains. However, the ongoing pandemic is fueled by variants of concern (VOC) escaping vaccine-mediated protection. Here we demonstrate how immunization in hamsters using prototypic spike expressed from yellow fever 17D (YF17D) as vector blocks ancestra...
The emergence of Omicron sublineages impact the therapeutic efficacy of anti-SARS-CoV-2 monoclonal antibodies (mAbs). Here, we evaluate neutralization and ADCC activities of 6 therapeutic mAbs against Delta, BA.2, BA.4 and BA.5. The Omicron subvariants escape most antibodies but remain sensitive to Bebtelovimab and Cilgavimab. Consistent with their...
An adequate SARS-CoV-2 genomic surveillance strategy has proven to be essential for countries to obtain a thorough understanding of the variants and lineages being imported and successfully established within their borders. During 2020, genomic surveillance in Belgium was not structurally implemented but performed by individual research laboratorie...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations and represent an antigenic shift resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma neutralizing activity against Omicron BA.1, BA.2, BA.2.12.1...
Remdesivir was the first drug to be approved for the treatment of severe COVID-19; followed by molnupiravir (another prodrug of a nucleoside analogue) and the protease inhibitor nirmatrelvir. Combination of antiviral drugs may result in improved potency and help to avoid or delay the development of resistant variants. We set out to explore the comb...
During co-translational translocation, the signal peptide of a nascent chain binds Sec61 translocon to initiate protein transport through the ER membrane. Our cryo-EM structure of ribosome-Sec61 shows binding of an ordered heterotetrameric TRranslocon-Associated Protein (TRAP) complex, in which TRAP-γ is anchored at two adjacent positions of 28S rR...
Comparable to the related Ebola virus, Marburg virus is an emerging zoonotic pathogen that causes hemorrhagic fever with a high mortality rate. Therefore, handling of Ebola virus and Marburg virus is limited to biosafety level 4 facilities, of which only a limited number exists worldwide. However, researchers have developed several virus alternativ...
Urtica dioica agglutinin (UDA) is a carbohydrate-binding small monomeric protein isolated from stinging nettle rhizomes. It inhibits replication of a broad range of viruses, including coronaviruses, in multiple cell types, with appealing selectivity. In this work, we investigated the potential of UDA as a broad-spectrum antiviral agent against SARS...
The emergence of novel Omicron lineages, such as BA.5, may impact the therapeutic efficacy of anti-SARS-CoV-2 neutralizing monoclonal antibodies (mAbs). Here, we evaluated the neutralization and ADCC activity of 6 therapeutic mAbs against Delta, BA.2, BA.4 and BA.5 isolates. The Omicron sub-variants escaped most of the antibodies but remained sensi...
SARS-CoV-2 omicron BA.4 and BA.5, characterized by high transmissibility and ability to escape natural and vaccine induced immunity, are rampaging worldwide. To understand the escape mechanisms, we tested the neutralizing activity against omicron BA.4 and BA.5 of a panel of 482 human monoclonal antibodies that had been isolated from people who rece...
After switching from 13-valent to 10-valent pneumococcal conjugate vaccine (PCV10) (2015-2016) for children in Belgium, we observed rapid reemergence of serotype 19A invasive pneumococcal disease (IPD). Whole-genome sequencing of 166 serotype 19A IPD isolates from children (n = 54) and older adults (n = 56) and carriage isolates from healthy childr...
Background
We performed exhaled breath (EB) and nasopharyngeal (NP) qPCR and NP rapid antigen testing (RAT) throughout SARS-CoV-2 infections with different variants.
Methods
We recruited immuno-naïve alpha-infected (n=11) and partly boosted omicron-infected patients (n=8) as high-risk contacts. We compared peak NP and EB qPCR cycle time (CT) value...
Comparable to the related Ebola virus, Marburg virus is an emerging zoonotic pathogen that causes hemorrhagic fever with a high mortality rate. Therefore, handling of Ebola virus and Marburg virus is limited to biosafety level 4 facilities, of which only a limited number exists worldwide. However, researchers have developed several virus alternativ...
BK polyomavirus (BKPyV) is a human DNA virus generally divided into twelve subgroups based on the genetic diversity of Viral Protein 1 (VP1). BKPyV can cause polyomavirus-associated nephropathy (PVAN) after kidney transplantation. Detection of BKPyV DNA in blood (viremia) is a source of concern and increase in plasma viral load is associated with a...