SARS-CoV-2 reinfection with a virus harboring mutation in the Spike and the Nucleocapsid proteins in Panama

Abstract Background Recent studies indicate that, in addition to antibody production, lymphocyte responses to SARS-CoV-2 may play an important role in protective immunity to COVID-19 and a percentage of the general population may exhibit lymphocyte memory due to unknown/asymptomatic exposure to SARS-CoV-2 or cross-reactivity to other more common coronaviruses pre-vaccination. Total joint replacement (TJR) candidates returning to elective surgeries (median age 68 years) may exhibit similar lymphocyte and/or antibody protection to COVID-19 prior to vaccination Methods In this retrospective study, we analyzed antibody titters, lymphocyte memory, and inflammatory biomarkers specific for the Spike and Nucleocapsid proteins of the SARS-CoV-2 virus in a cohort of n=73 returning TJR candidates (knees and/or hips) pre-operatively. Results Peripheral blood serum of TJR candidate patients exhibited a positivity rate of 18.4% and 4% for IgG antibodies specific for SARS-CoV-2 nucleocapsid and spike proteins, respectively. 13.5% of TJR candidates exhibited positive lymphocyte reactivity (SI > 2) to the SARS-CoV-2 nucleocapsid protein and 38% to the spike protein. SARS-CoV-2 reactive lymphocytes exhibited a higher production of inflammatory biomarkers (i.e., IL-1β, IL-6, TNFα, and IL-1RA) compared to non-reactive lymphocytes. Conclusions A percentage of TJR candidates returning for elective surgeries exhibit pre-vaccination positive SARS-CoV-2 antibodies and T cell memory responses with associated pro-inflammatory biomarkers. This is an important parameter for understanding immunity, risk profiles, and may aid pre-operative planning. Trial registration Retrospectively registered.

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IgG and IgM antibody formation to spike and nucleocapsid proteins in COVID-19 characterized by multiplex immunoblot assays

BMC Infectious Diseases ◽

10.1186/s12879-021-06031-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jyotsna Shah ◽

Song Liu ◽

Hari-Hara Potula ◽

Prerna Bhargava ◽

Iris Cruz ◽

...

Keyword(s):

Viral Infections ◽

Antibody Responses ◽

Nucleocapsid Proteins ◽

Igm Antibodies ◽

Igm Antibody ◽

Specificity And Sensitivity ◽

The Us ◽

Autoimmune Conditions ◽

Antibody Positivity ◽

Recombinant Nucleocapsid Protein

Abstract Background Rapid and simple serological assays for characterizing antibody responses are important in the current COVID-19 pandemic caused by SARS-CoV-2. Multiplex immunoblot (IB) assays termed COVID-19 IB assays were developed for detecting IgG and IgM antibodies to SARS-CoV-2 virus proteins in COVID-19 patients. Methods Recombinant nucleocapsid protein and the S1, S2 and receptor binding domain (RBD) of the spike protein of SARS-CoV-2 were used as target antigens in the COVID-19 IBs. Specificity of the IB assay was established with 231 sera from persons with allergy, unrelated viral infections, autoimmune conditions and suspected tick-borne diseases, and 32 goat antisera to human influenza proteins. IgG and IgM COVID-19 IBs assays were performed on 84 sera obtained at different times after a positive RT-qPCR test from 37 COVID-19 patients with mild symptoms. Results Criteria for determining overall IgG and IgM antibody positivity using the four SARS-CoV-2 proteins were developed by optimizing specificity and sensitivity in the COVID-19 IgG and IgM IB assays. The estimated sensitivities and specificities of the COVID-19 IgG and IgM IBs for IgG and IgM antibodies individually or for either IgG or IgM antibodies meet the US recommendations for laboratory serological diagnostic tests. The proportion of IgM-positive sera from the COVID-19 patients following an RT-qPCR positive test was maximal at 83% before 10 days and decreased to 0% after 100 days, while the proportions of IgG-positive sera tended to plateau between days 11 and 65 at 78–100% and fall to 44% after 100 days. Detection of either IgG or IgM antibodies was better than IgG or IgM alone for assessing seroconversion in COVID-19. Both IgG and IgM antibodies detected RBD less frequently than S1, S2 and N proteins. Conclusions The multiplex COVID-19 IB assays offer many advantages for simultaneously evaluating antibody responses to different SARS-CoV-2 proteins in COVID-19 patients.

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Mutational hotspots and conserved domains of SARS-CoV-2 genome in African population

Beni-Suef University Journal of Basic and Applied Sciences ◽

10.1186/s43088-021-00102-1 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Olabode E. Omotoso ◽

Ayoade D. Babalola ◽

Amira Matareek

Keyword(s):

Global Economy ◽

African Population ◽

The Novel ◽

Conserved Domains ◽

Nucleocapsid Proteins ◽

Genome Variability ◽

Promising Strategy ◽

Mutational Hotspots ◽

Novel Coronavirus ◽

Complete Protein

Abstract Background Since outbreak in December 2019, the highly infectious and pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused over a million deaths globally. With increasing burden, the novel coronavirus has posed a dire threat to public health, social interaction, and global economy. Mutations in the SARS-CoV-2 genome are moderately evolving which might have contributed to its genome variability, transmission, replication efficiency, and virulence in different regions of the world. Results The present study elucidated the mutational landscape in the SARS-CoV-2 genome among the African populace, which may have contributed to the virulence, spread, and pathogenicity observed in the region. A total of 3045 SARS-CoV-2 complete protein sequences with the reference viral sequence (EPI_ISL_402124) were mined and analyzed. SARS-CoV-2 ORF1ab, spike, ORF3, ORF8, and nucleocapsid proteins were observed as mutational hotspots in the African population and may be of keen interest in understanding the viral host relationship, while there is conservation in the ORF6, ORF7a, ORF7b, ORF10, envelope, and membrane proteins. Conclusions The accumulation of moderate mutations (though slowly), in the SARS-CoV-2 genome as seen in this present study, could be a promising strategy to develop antiviral drugs or vaccines. These antiviral interventions should target viral conserved domains and host cellular proteins and/or receptors involved in viral invasion and replication to avoid a new viral wave due to drug resistance and vaccine evasion.

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Use of recombinant nucleocapsid proteins of the hantaan and nephropathia epidemica serotypes of Hantaviruses as immunodiagnostic antigens

Journal of Medical Virology ◽

10.1002/jmv.1890390305 ◽

1993 ◽

Vol 39 (3) ◽

pp. 200-207 ◽

Cited By ~ 42

Author(s):

L. Zöller ◽

S. Yang ◽

P. Gött ◽

E. K. F. Bautz ◽

G. Darai

Keyword(s):

Nephropathia Epidemica ◽

Nucleocapsid Proteins

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Autographa californica Nucleopolyhedrovirus AC141 (Exon0), a Potential E3 Ubiquitin Ligase, Interacts with Viral Ubiquitin and AC66 To Facilitate Nucleocapsid Egress

Journal of Virology ◽

10.1128/jvi.01713-17 ◽

2017 ◽

Vol 92 (3) ◽

Cited By ~ 4

Author(s):

Siddhartha Biswas ◽

Leslie G. Willis ◽

Minggang Fang ◽

Yingchao Nie ◽

David A. Theilmann

Keyword(s):

Ubiquitin Ligase ◽

Nuclear Export ◽

Molecular Mechanisms ◽

Nuclear Periphery ◽

E3 Ubiquitin Ligase ◽

Autographa Californica ◽

Nucleocapsid Proteins ◽

Systemic Spread ◽

Autographa Californica Nucleopolyhedrovirus ◽

Budded Virus

ABSTRACTDuring the infection cycle of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), two forms of virions are produced, budded virus (BV) and occlusion-derived virus (ODV). Nucleocapsids that form BV have to egress from the nucleus, whereas nucleocapsids that form ODV remain inside the nucleus. The molecular mechanism that determines whether nucleocapsids remain inside or egress from the nucleus is unknown. AC141 (a predicted E3 ubiquitin ligase) and viral ubiquitin (vUbi) have both been shown to be required for efficient BV production. In this study, it was hypothesized that vUbi interacts with AC141, and in addition, that this interaction was required for BV production. Deletion of bothac141andvubirestricted viral infection to a single cell, and BV production was completely eliminated. AC141 was ubiquitinated by either vUbi or cellular Ubi, and this interaction was required for optimal BV production. Nucleocapsids in BV, but not ODV, were shown to be specifically ubiquitinated by vUbi, including a 100-kDa protein, as well as high-molecular-weight conjugates. The viral ubiquitinated 100-kDa BV-specific nucleocapsid protein was identified as AC66, which is known to be required for BV production and was shown by coimmunoprecipitation and mass spectrometry to interact with AC141. Confocal microscopy also showed that AC141, AC66, and vUbi interact at the nuclear periphery. These results suggest that ubiquitination of nucleocapsid proteins by vUbi functions as a signal to determine if a nucleocapsid will egress from the nucleus and form BV or remain in the nucleus to form ODV.IMPORTANCEBaculoviruses produce two types of virions called occlusion-derived virus (ODV) and budded virus (BV). ODVs are required for oral infection, whereas BV enables the systemic spread of virus to all host tissues, which is critical for killing insects. One of the important steps for BV production is the export of nucleocapsids out of the nucleus. This study investigated the molecular mechanisms that enable the selection of nucleocapsids for nuclear export instead of being retained within the nucleus, where they would become ODV. Our data show that ubiquitination, a universal cellular process, specifically tags nucleocapsids of BV, but not those found in ODV, using a virus-encoded ubiquitin (vUbi). Therefore, ubiquitination may be the molecular signal that determines if a nucleocapsid is destined to form a BV, thus ensuring lethal infection of the host.

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