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1.
Biomedicines ; 10(11)2022 Nov 11.
Article in English | MEDLINE | ID: covidwho-2109932

ABSTRACT

Throughout the pandemic, serological assays have been revealed as crucial for detecting previous exposures to the virus and determining the timing of antibody maintenance after vaccination or natural infection. This study aimed to develop an optimized enzyme-linked immunosorbent assay (ELISA)-based serology, which could be used in case of reagent shortages, such as that occurred in the beginning of this health emergency. As a result, we present a high-sensitive immunoassay for the determination of IgG levels in venous serum samples, using 2 µg/mL antigen (receptor-binding domain of the spike protein S1) for coating the plate and utilizing human samples at a dilution 1:1000. This method showed non-inferiority features versus a commercial kit, is less expensive, and has a higher spectrophotometric range that allows for a better quantification of the antibody titers. The optical density values before and after heating venous serum samples at 56 °C during 30 min was quite similar, showing that heat inactivation can be used to reduce the biohazardous risks while handling samples. Furthermore, we show that finger-stick capillary blood samples can also serve as a suitable source for IgG detection, bypassing the need for serum isolation and being suitable for point-of-care application (Pearson's coefficient correlation with capillary serum was 0.95, being statistically significant).

2.
J Clin Periodontol ; 2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2108075

ABSTRACT

AIM: Aerosols released from the oral cavity help spread the SARS-CoV-2 virus. The use of a mouthwash formulated with an antiviral agent could reduce the viral load in saliva, helping to lower the spread of the virus. The aim of this study was to assess the efficacy of a mouthwash with 0.07% cetylpyridinium chloride (CPC) to reduce the viral load in the saliva of Coronavirus disease 2019 (COVID-19) patients. MATERIALS AND METHODS: In this multi-centre, single-blind, randomized, parallel group clinical trial, 80 COVID-19 patients were enrolled and randomized to two groups, namely test (n = 40) and placebo (n = 40). Saliva samples were collected at baseline and 2 h after rinsing. The samples were analysed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and an enzyme-linked immunosorbent assay test specific for the nucleocapsid (N) protein of SARS-CoV-2. RESULTS: With RT-qPCR, no significant differences were observed between the placebo group and the test group. However, 2 h after a single rinse, N protein concentration in saliva was significantly higher in the test group, indicating an increase in lysed virus. CONCLUSIONS: The use of 0.07% CPC mouthwash induced a significant increase in N protein detection in the saliva of COVID-19 patients. Lysis of the virus in the mouth could help reduce the transmission of SARS-CoV-2. However, more studies are required to prove this.

3.
Protein Expr Purif ; 203: 106200, 2022 Nov 13.
Article in English | MEDLINE | ID: covidwho-2105707

ABSTRACT

Among the main structural protein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), nucleocapsid phosphoprotein (NP) exhibits high immunogenicity and is the most abundant viral protein produced and shed during infection. Detection of antibodies against NP may help assess the number of individuals exposed to SARS-COV-2 or vaccinated against it. Based on these findings and other structural and antigenic evaluations, we designed a recombinant truncated fusion NP-based protein for application in an immunoassay for detecting immunoglobulins in patients who have recovered from COVID-19. In this research, we aligned the NPs from SARS-CoV and SARS-CoV-2 and selected highly antigenic parts of the SARS-CoV-2 sequences based on in-silico studies. The protein was expressed under optimum conditions in the bacterial host BL21 and purified by nickel immobilized metal affinity chromatography. Moreover, the purity level was assessed by SDS-PAGE and Western blotting whereas the folding of the protein was evaluated by circular dichroism. Ultimately, we used the purified recombinant protein in ELISA development in which 42 samples from convalescent patients were compared with 20 samples of the past 2019 patients who had attended laboratories for various clinical check-ups. The sensitivity and specificity were determined as 71% and 90%, respectively, in the optimum cut-off point measured by the receiver operating characteristic curve.

4.
J Immunol Methods ; 511: 113365, 2022 Oct 04.
Article in English | MEDLINE | ID: covidwho-2105378

ABSTRACT

Considering the course of the current SARS-CoV-2 pandemic, it is important to have serological tests for monitoring humoral immune response against SARS-CoV-2 infection and vaccination. Herein we describe a novel bridge enzyme-linked immunosorbent assay (b-ELISA) for SARS-CoV-2 antibodies detection in human and other species, employing recombinant Spike protein as a unique antigen, which is produced at high scale in insect larvae. METHODS: Eighty two human control sera/plasmas and 169 COVID-19 patients' sera/plasmas, confirmed by rRT-PCR, were analyzed by the b-ELISA assay. In addition, a total of 27 animal sera (5 horses, 13 rats, 2 cats and 7 dogs) were employed in order to evaluate the b-ELISA in other animal species. RESULTS: Out of the 169 patient samples, 129 were positive for IgG anti-SARS-CoV-2 and 40 were negative when they were tested by ELISA COVIDAR® IgG. When a cut-off value of 5.0 SDs was established, 124 out of the 129 COVID-19 positive samples were also positive by our developed b-ELISA (sensitivity: 96.12%). Moreover, the test was able to evaluate the humoral immune response in animal models and also detected as positive a naturally infected cat and two dogs with symptoms, whose owners had suffered the COVID-19 disease. CONCLUSION: The obtained results demonstrate that the method developed herein is versatile, as it is able to detect antibodies against SARS-CoV-2 in different animal species without the need to perform and optimize a new assay for each species.

5.
Appl Microbiol Biotechnol ; 106(23): 7933-7948, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2103864

ABSTRACT

Serology assays are essential tools to mitigate the effect of COVID-19, help to identify previous SARS-CoV-2 infections or vaccination, and provide data for surveillance and epidemiologic studies. In this study, we report the production and purification process of the receptor-binding domain (RBD) of SARS-CoV-2 in HEK293 cells, which allowed the design, optimization, and validation of an indirect ELISA (iELISA) for the detection of human anti-RBD antibodies. To find the optimal conditions of this iELISA, a multivariate strategy was performed throughout design of experiments (DoE) and response surface methodology (RSM), one of the main tools of quality by design (QbD) approach. The adoption of this strategy helped to reduce the time and cost during the method development stage and to define an optimum condition within the analyzed design region. The assay was then validated, exhibiting a sensitivity of 94.24 (86.01-98.42%; 95% CI) and a specificity of 95.96% (89.98-98.89%; 95% CI). Besides, the degree of agreement between quality results assessed using kappa's value was 0.92. Hence, this iELISA represents a high-throughput technique, simple to perform, reliable, and feasible to be scaled up to satisfy the current demands. Since RBD is proposed as the coating antigen, the intended use of this iELISA is not only the detection of previous exposure to the virus, but also the possibility of detecting protective immunity. KEY POINTS: • RBD was produced in 1-L bioreactor and highly purified. • An iELISA assay was optimized applying QbD concepts. • The validation procedure demonstrated that this iELISA is accurate and precise.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , COVID-19/diagnosis , HEK293 Cells , Antibodies, Viral , Enzyme-Linked Immunosorbent Assay , Immunoglobulin G , Spike Glycoprotein, Coronavirus
6.
Front Cardiovasc Med ; 9: 1012452, 2022.
Article in English | MEDLINE | ID: covidwho-2099118
7.
BMC Infect Dis ; 22(1): 810, 2022 Oct 31.
Article in English | MEDLINE | ID: covidwho-2098319

ABSTRACT

BACKGROUND: There is limited information to compare the qualitative and semi-quantitative performance of rapid diagnostic tests (RDT) and serology for the assessment of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, the objective of the study was (a) to compare the efficacy of SARS-CoV-2 antibody detection between RDT and laboratory serology, trying to identify appropriate semi-quantitative cut-offs for RDT in relation with quantitative serology values and to (b) evaluate diagnostic accuracy of RDT compared to the NAAT gold standard in an unselected adult population. METHODS: SARS-CoV-2 antibodies were simultaneously measured with lateral flow immunochromatographic assays (LFA), the Cellex qSARS-CoV-2 IgG/IgM Rapid Test (by capillary blood), the iFlash-SARS-CoV-2 IgG/IgM chemiluminescent immunoassay (CLIA) (by venous blood) and the nucleic acid amplification test (NAAT) in samples from in- and out-patients with confirmed, suspected and negative diagnosis of coronavirus disease 2019 (COVID-19) attending Udine Hospital (Italy) (March-May 2020). Interpretation of RDT was qualitative (positive/negative) and semi-quantitative based on a chromatographic intensity scale (negative, weak positive, positive). RESULTS: Overall, 720 paired antibody measures were performed on 858 patients. The qualitative and semiquantitative agreement analysis performed in the whole sample between LFA and CLIA provided a Kendall's tau of 0.578 (p < 0.001) and of 0.623 (p < 0.001), respectively, for IgM and IgG. In patients with a diagnosis of COVID-19, accordance between LFA and CLIA was maintained as a function of time from the onset of COVID-19 disease and the severity of disease both for qualitative and semi-quantitative assessments. RDT compared to the NAAT gold standard in 858 patients showed 78.5% sensitivity (95% CI 75.1%-81.7%) and 94.1% specificity (95% CI 90.4%-96.8%), with variable accordance depending on the timing from symptom onset. CONCLUSION: The RDT used in our study can be a non-invasive and reliable alternative to serological tests and facilitate both qualitative and a semi-quantitative antibody detection in COVID-19.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Humans , COVID-19/diagnosis , Prospective Studies , Immunoglobulin M , Sensitivity and Specificity , Antibodies, Viral , Immunoglobulin G , Immunoassay/methods
8.
J Infect Dis ; 2022 Oct 31.
Article in English | MEDLINE | ID: covidwho-2097372

ABSTRACT

BACKGROUND: Evaluating the performance of SARS-CoV-2 serological assays and clearly articulating the utility of selected antigen, isotypes and thresholds is crucial to understanding the prevalence of infection within selected communities. METHODS: This cross-sectional study, implemented in 2020, screened PCR-confirmed COVID-19 patients (n = 86), banked pre-pandemic and negative donors (n = 96), health care workers and family members (n = 552), and university employees (n = 327) for anti-SARS-CoV-2 receptor-binding domain (RBD), trimeric spike protein (S), and nucleocapsid protein (N) IgG and IgA antibodies with a laboratory developed Enzyme-Linked Immunosorbent Assay (ELISA) and tested how antigen, isotype and threshold choices affected the seroprevalence. The following threshold methods were evaluated: (i) mean + 3 standard deviations of the negative controls; (ii) 100% specificity for each antigen/isotype combination; and (iii) the maximal Youden index. RESULTS: We found vastly different seroprevalence estimates depending on selected antigens, isotypes and the applied threshold method, ranging from 0.0% to 85.4% . Subsequently, we maximized specificity and reported a seroprevalence, based on more than one antigen, ranging from 9.3% to 25.9%. CONCLUSIONS: This study revealed the importance of evaluating serosurvey tools for antigen, isotype, and threshold-specific sensitivity and specificity, in order to interpret qualitative serosurvey outcomes reliably and consistently across studies.

9.
Curr Issues Mol Biol ; 44(11): 5260-5276, 2022 Oct 28.
Article in English | MEDLINE | ID: covidwho-2090026

ABSTRACT

Coronavirus 2019 (COVID-19) disease management is highly dependent on the immune status of the infected individual. An increase in the incidence of depression has been observed during the ongoing COVID-19 pandemic. Autoantibodies against in vitro reactive oxygen species (ROS) modified BSA and Lys as well as antibodies against receptor binding domain subunit S1 (S1-RBD) (S1-RBD-Abs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were estimated using direct binding and competition ELISA. Serum samples were also tested for fasting blood glucose (FBG), malondialdehyde (MDA), carbonyl content (CC), interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Significant structural changes were observed in ROS modified BSA and Lys. Female depressed subjects who were also smokers (F-D-S) showed the highest levels of oxidative stress (MDA and CC levels). Similarly, increased levels of autoantibodies against ROS modified proteins were detected in F-D-S subjects, in males who were depressed and in smokers (M-D-S) compared to the other subjects from the rest of the groups. However, contrary to this observation, levels of S1-RBD-Abs were found to be lowest in the F-D-S and M-D-S groups. During the pandemic, large numbers of individuals have experienced depression, which may induce excessive oxidative stress, causing modifications in circulatory proteins. Thus, the formation of neo-antigens is induced, which lead to the generation of autoantibodies. The concomitant effect of increased autoantibodies with elevated levels of IFN-γ and TNF-α possibly tilt the immune balance toward autoantibody generation rather than the formation of S1-RBD-Abs. Thus, it is important to identify individuals who are at risk of depression to determine immune status and facilitate the better management of COVID-19.

10.
Makara Journal of Science ; 26(3):145-150, 2022.
Article in English | Scopus | ID: covidwho-2090823

ABSTRACT

COVID-19 caused by SARS-CoV-2 poses a major threat to the global community, particularly in Indonesia. Countermeasures to prevent the spread of this disease have also been implemented, including the implementation of a vaccination program. An immunoassay technique that can be used to analyze antibodies that might develop following vaccination is the indirect enzyme-linked immunosorbent assay (ELISA). We produced the recombinant spike protein used in this study. The optimization comprised adjusted concentrations of spike recombinant protein (5 and 10 ng/mL), blocking agent (2.5% and 5%), and conjugate (1:1000 and 1:5000). The optimal conditions in this study included a spiked concentration of 10 ng/mL, a blocking agent concentration of 5%, sample dilution of 1:33, and a conjugate concentration of 1:1000. The intra-assay value of this optimized indirect ELISA was 7.3, and the inter-assay value was 5.3. The commercial MyBioSource kit and immunodiagnostic were utilized as a reference in the T-test, with P-values of 0 and 0.313, indicating that the recombinant protein in-house ELISA kit in this study demonstrated the same ability as the commercial immunodiagnostic kit in detecting SARS-CoV-2 antibodies, allowing it to be used for post-vaccination efficacy evaluation. © 2022, Universitas Indonesia. All rights reserved.

11.
Comput Biol Med ; 151(Pt A): 106212, 2022 Oct 25.
Article in English | MEDLINE | ID: covidwho-2086096

ABSTRACT

The number of SARS-CoV-2 spike Receptor Binding Domain (RBD) with multiple amino acid mutations is huge due to random mutations and combinatorial explosions, making it almost impossible to experimentally determine their binding affinities to human angiotensin-converting enzyme 2 (hACE2). Although computational prediction is an alternative way, there is still no online platform to predict the mutation effect of RBD on the hACE2 binding affinity until now. In this study, we developed a free online platform based on deep learning models, namely D3AI-Spike, for quickly predicting binding affinity between spike RBD mutants and hACE2. The models based on CNN and CNN-RNN methods have the concordance index of around 0.8. Overall, the test results of the models are in agreement with the experimental data. To further evaluate the prediction power of D3AI-Spike, we predicted and experimentally determined the binding affinity of a VUM (variants under monitoring) variant IHU (B.1.640.2), which has fourteen amino acid substitutions, including N501Y and E484K, and 9 deletions located in the spike protein. The predicted average affinity score for wild-type RBD and IHU to hACE2 are 0.483 and 0.438, while the determined Kaff values are 5.39 ± 0.38 × 107 L/mol and 1.02 ± 0.47 × 107 L/mol, respectively, demonstrating the strong predictive power of D3AI-Spike. We think D3AI-Spike will be helpful to the viral transmission prediction for the new emerging SARS-CoV-2 variants. D3AI-Spike is now available free of charge at https://www.d3pharma.com/D3Targets-2019-nCoV/D3AI-Spike/index.php.

12.
Cureus ; 14(8): e28530, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-2082400

ABSTRACT

With the emergence of Coronavirus infection called COVID-19, testing is essential for containment and mitigation purposes. In a pandemic, control is essential to limit the spread of any virus. Initially, contact tracing was not available which ultimately led to the 2020 pandemic. However, with the development of COVID-19 rapid testing, the rate of infections has lessened and has allowed for some return to normalcy. In this review, we discuss the various antibody, antigens, and molecular tests that have been given emergency authorization (EA) from the Food and Drug Administration (FDA). Moreover, we will discuss the various point-of-care tests as well as the specificity and sensitivity that are associated with each testing kit. With appropriate testing, we can be aware of how the virus spreads and how prevalent it remains.

13.
Vaccines (Basel) ; 10(10)2022 Oct 20.
Article in English | MEDLINE | ID: covidwho-2082123

ABSTRACT

The COVID-19 pandemic has revealed a crucial need for rapid, straightforward collection and testing of biological samples. Serological antibody assays can analyze patient blood samples to confirm immune response following mRNA vaccine administration or to verify past exposure to the SARS-CoV-2 virus. While blood tests provide vital information for clinical analysis and epidemiology, sample collection is not trivial; this process requires a visit to the doctor's office, a professionally trained phlebotomist to draw several milliliters of blood, processing to yield plasma or serum, and necessitates appropriate cold chain storage to preserve the specimen. A novel whole blood collection kit (truCOLLECT) allows for a lancet-based, decentralized capillary blood collection of metered low volumes and eliminates the need for refrigerated transport and storage through the process of active desiccation. Anti-SARS-CoV-2 spike (total and neutralizing) and nucleocapsid protein antibody titers in plasma samples obtained via venipuncture were compared to antibodies extracted from desiccated whole blood using Adaptive Focused Acoustics (AFA). Paired plasma versus desiccated blood extracts yields Pearson correlation coefficients of 0.98; 95% CI [0.96, 0.99] for anti-SARS-CoV-2 spike protein antibodies, 0.97; 95% CI [0.95, 0.99] for neutralizing antibodies, and 0.97; 95% CI [0.94, 0.99] for anti-SARS-CoV-2 nucleocapsid protein antibodies. These data suggest that serology testing using desiccated and stabilized whole blood samples can be a convenient and cost-effective alternative to phlebotomy.

14.
Pathogens ; 11(11)2022 Oct 24.
Article in English | MEDLINE | ID: covidwho-2082038

ABSTRACT

After the recent Middle East Respiratory Syndrome coronavirus (MERS-CoV) pandemic in 2013, more attention has been paid to the camel as an important source of zoonotic viral infections. Almost simultaneously, in 2013, new genotypes 7 and 8 of the hepatitis E virus (HEV) were discovered in dromedary and Bactrian camels, respectively. HEV 7 was further shown to be associated with chronic viral hepatitis in a transplant recipient. In this study, serological screening for antibodies to MERS-CoV and hepatitis E virus was carried out on large camel farms in the south and west of Kazakhstan. 6.42% of the tested camels were found to be positive for antibodies to the hepatitis E virus, which indicates its circulation in local camel population. For the first time, antibodies to the hepatitis E virus were found in Bactrians, which have been little studied to date. Antibodies to MERS-CoV were not found in the camel sera.

15.
J Med Virol ; 2022 Oct 13.
Article in English | MEDLINE | ID: covidwho-2075076

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic has a significant global social and economic impact, and the emergence of new and more destructive mutant strains highlights the need for accurate virus detection. Here, 90 monoclonal antibodies (MAbs) that exclusively reacted with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (NP) were generated. These MAbs did not cross-react with NPs of common human coronaviruses (HCoVs, i.e., 229E, OC43, HKU1, and NL63) and Middle East Respiratory Syndrome Coronavirus. Subsequently, overlapped peptides in individual fragments (N1-N4) of NP were synthesized. N1-3 (25-GSNQNGERSGARSKQ-39), N3-1 (217-AALALLLLDRLNQL-230), and N4-8 (393-TLLPAADLDDFSKQL-407) were identified as major epitopes using enzyme-linked immunoassay (ELISA) and recognized by 47, 1, and 18 MAbs, respectively. The 24 remaining MAbs exhibited no reactivity with all synthetic peptides. Among MAb-epitope pairs, only MAbs targeting epitope N1-3 displayed no cross-reaction with NPs of SARS-CoV-1 and other SARS-related CoVs. All Omicron variants contained a three-amino acid deletion (31ERS33) in the N1-3 region. Thus, MAbs targeting N1-3 failed to recognize these variants. Furthermore, a double-antibody sandwich ELISA for antigen detection was established using the optimal MAbs. Overall, a series of MAbs targeting SARS-CoV-2 NP was prepared, characterized with epitope mapping, and applied for the detection of SARS-CoV-2 antigens, and some novel B-cell epitopes of the viral NP were identified.

16.
J Med Virol ; 2022 Oct 17.
Article in English | MEDLINE | ID: covidwho-2075074

ABSTRACT

A multitude of enzyme-linked immunosorbent assays (ELISAs) has been developed to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies since the coronavirus disease 2019 pandemic started in late 2019. Assessing the reliability of these assays in diverse global populations is critical. This study compares the use of the commercially available Platelia Total Ab Assay (Bio-Rad) nucleocapsid ELISA to the widely used Mount Sinai spike IgG ELISA in a Kenyan population seroprevalence study. Using longitudinal plasma specimens collected from a mother-infant cohort living in Nairobi, Kenya between May 2019 and December 2020, this study demonstrates that the two assays have a high qualitative agreement (92.7%) and strong correlation of antibody levels (R2 = 0.973) in repeated measures. Within this cohort, seroprevalence detected by either ELISA closely resembled previously published seroprevalence estimates for Kenya during the sampling period and no significant difference in the incidence of SARS-CoV-2 antibody detection by either assay was observed. Assay comparability was not affected by HIV exposure status. These data support the use of the Platelia SARS-CoV-2 Total Ab ELISA as a suitable high-throughput method for seroprevalence studies in Kenya.

17.
Cureus ; 14(9): e29296, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-2072206

ABSTRACT

Background Patients with chronic kidney disease and undergoing hemodialysis are at greater risk of developing COVID-19. In spite of vaccine efficacy, SARS-CoV-2 breakthrough infection has been reported in several studies. This study was carried out to assess if seroconversion could predict SARS-CoV-2 breakthrough infection in a cohort of vaccinated patients undergoing hemodialysis. Methodology Patients undergoing maintenance hemodialysis for at least three months and who had received two doses of BBV152 or AZD1222 vaccine were included in the study. Their baseline IgG antibodies to SARS-CoV-2 were measured and followed up for a median of three months during the third wave of COVID-19 in India with SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) to detect breakthrough infections. Results Of 80 patients enrolled, seroconversion was seen in 81% of the cases, and SARS-CoV-2 breakthrough cases have been detected in 16% (13/80; 95% CI 8.95-26.18) patients undergoing hemodialysis. Of the 13 patients, seven patients required hospitalization and others had a mild outcome. There was no correlation of baseline seropositivity with breakthrough infections or hospitalization. Conclusions A majority of patients who underwent hemodialysis are seropositive post-vaccination. The breakthrough infection did not correlate with baseline seroconversion. Thus, there would be other predictors of breakthrough COVID-19 infections that need to be recognized in this susceptible population.

18.
Cureus ; 14(9): e29138, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-2072193

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus caused coronavirus infection termed as COVID-19, an illness that has spread devastation all over the world. It was developed first in China and had swiftly spread throughout the world. COVID has created imposed burden on health in the lives of all individuals around the globe. This article provides a number of unprecedented detection technologies used in the detection of infection. COVID has created a large number of symptoms in the young, adolescent as well as elderly population. Old age people are susceptible to fatal serious symptoms because of low immunity. With these goals in mind, this article includes substantial condemning descriptions of the majority of initiatives in order to create diagnostic tools for easy diagnosis. It also provides the reader with a multidisciplinary viewpoint on how traditional approaches such as serology and reverse transcriptase polymerase chain reaction (RT-PCR) along with the frontline techniques such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas and artificial intelligence/machine learning have been utilized to gather information. The story will inspire creative new ways for successful detection therapy and to prevent this pandemic among a wide audience of operating and aspiring biomedical scientists and engineers.

19.
Int J Mol Sci ; 23(20)2022 Oct 17.
Article in English | MEDLINE | ID: covidwho-2071517

ABSTRACT

Transmembrane glycoprotein integrins play crucial roles in biochemical processes, and by their inhibition or activation, different signal pathways can be disrupted, leading to abnormal physiological functions. We have previously demonstrated the inhibitory effect of glyphosate herbicide's active ingredient on cell adhesion and its αvß3 integrin antagonist effect. Therefore, it appeared particularly exciting to investigate inhibition of glyphosate and its metabolites on a wider range of Arg-Gly-Asp (RGD) binding integrins, namely αvß3, α5ß1 and αllbß3. Thus, the purpose of this study was to assess how extended the inhibitory effect observed for glyphosate on the integrin αvß3 is in terms of other RGD integrins and other structurally or metabolically related derivatives of glyphosate. Five different experimental setups using enzyme-linked immunosorbent assays were applied: (i) αvß3 binding to a synthetic polymer containing RGD; (ii) αvß3 binding to its extracellular matrix (ECM) protein, vitronectin; (iii) α5ß1 binding to the above polymer containing RGD; (iv) αllbß3 binding to its ECM protein, fibrinogen and (v) αvß3 binding to the SARS-CoV-2 spike protein receptor binding domain. Total inhibition of αvß3 binding to RGD was detected for glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA), as well as for acetylglycine on α5ß1 binding to RGD.


Subject(s)
COVID-19 , Herbicides , Humans , Integrin alphaVbeta3/metabolism , Vitronectin , Herbicides/pharmacology , SARS-CoV-2 , Oligopeptides/chemistry , Enzyme-Linked Immunosorbent Assay , Fibrinogen , Polymers
20.
Biomedicines ; 10(10)2022 Oct 11.
Article in English | MEDLINE | ID: covidwho-2071215

ABSTRACT

The interaction between programmed death-1 receptor PD-1 and its ligands PD-L1 and PD-L2 is involved in self-tolerance, immune escape of cancer, cardiovascular diseases, and COVID-19. As blood-based protein markers they bear great potential to improve oncoimmunology research and monitoring of anti-cancer immunotherapy. A variety of preanalytical conditions were tested to assure high quality plasma sample measurements: (i) different time intervals and storage temperatures before and after blood centrifugation; (ii) fresh samples and repeated freeze-thaw-cycles; (iii) different conditions of sample preparation before measurement. Concerning short-term stability, acceptable recoveries for PD-1 between 80 and 120% were obtained when samples were kept up to 24 h at 4 and 25 °C before and after blood centrifugation. Similarly, recoveries for PD-L2 were acceptable for 24 h at 4 °C and 6 h at 25 °C before blood centrifugation and up to 24 h at 4 and 25 °C after centrifugation. Variations for PD-L1 were somewhat higher, however, at very low signal levels. Sample concentrations (ng/mL) were neither affected by the freezing process nor by repeated freeze-thaw cycles with coefficients of variation for PD-1: 9.1%, PD-L1 6.8%, and PD-L2 4.8%. All three biomarkers showed good stability regarding preanalytic conditions of sample handling enabling reliable and reproducible quantification in oncoimmunology research and clinical settings of anti-cancer immunotherapy.

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