Molecular and computational analysis of spike protein of newly emerged omicron variant in comparison to the delta variant of SARS-CoV-2 in Iraq

Dynamics of SARS-CoV-2 Spike RBD Protein Mutation and Pathogenicity Consequences in Indonesian Circulating Variants in 2020-2022

BACKGROUND

Since the beginning of the coronavirus disease 2019 (COVID-19) outbreak, dynamic mutations in the receptor-binding domain (RBD) in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein have altered the pathogenicity of the variants of the virus circulating in Indonesia. This research analyzes the mutation trend in various RBD samples from Indonesia published in the Global Initiative on Sharing All Influenza Data (GISAID) database using genomic profiling.

METHOD

Patients in Indonesia infected with SARS-CoV-2, whose samples have been published in genomic databases, were selected for this research. The collected data were processed for analysis following several bioinformatics protocols: visualization into phylogenetic trees, 3D rendering, and the assessment of mutational impact.

RESULTS

In Indonesia, there are 25 unique SARS-CoV-2 clades and 318 unique SARS-CoV-2 RBD mutations from the earliest COVID-19 sample to samples collected in 2022, with T478K being the most prevalent RBD mutation and 22B being the most abundant clade. The Omicron variant has a lower docking score, higher protein destabilization, and higher KD than the Delta variant and the original virus.

CONCLUSIONS

The study findings reveal a decreasing trend in virus pathogenicity as a potential trade-off to increase transmissibility via mutations in RBD over the years.

An unconventional strategy for purifying recombinant SARS-CoV-2 spike protein

The soluble domain of the trimeric SARS-CoV-2 spike protein is a promising candidate for a COVID-19 vaccine. Purification of this protein from mammalian cell culture supernatant using conventional resin-based chromatography is challenging as its large size (∼550 kDa) restricts its access and mobility within the pores of the resin particles. This reduces binding capacity and process robustness very significantly as extremely low flow rates need to be used during purification. Convection-based ion-exchange membrane chromatography has been found to be suitable in this respect. However, the high ionic strength of mammalian cell culture supernatant makes it difficult to bind this protein on charged membranes without dilution with a suitable buffer. An unconventional strategy involving size-exclusion chromatography as the first step, followed by cation exchange membrane chromatography as the second step is proposed in this paper. In the size exclusion chromatography step, the spike protein is excluded from the pores and can therefore be isolated in the void volume fraction. This step removes small molecule impurities and also serves as a desalting and buffer exchange step, making the partially purified material suitable for the cation exchange membrane chromatography step. The proposed process is variant-independent, fast and scalable and addresses some of the challenges associated with the currently used purification methods.

Fast Viral Diagnostics: FTIR-Based Identification, Strain-Typing, and Structural Characterization of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered an ongoing global pandemic, necessitating rapid and accurate diagnostic tools to monitor emerging variants and preparedness for the next outbreak. This study introduces a multidisciplinary approach combining Fourier Transform Infrared (FTIR) microspectroscopy and Machine learning to comprehensively characterize and strain-type SARS-CoV-2 variants. FTIR analysis of pharyngeal swabs from different pandemic waves revealed distinct vibrational profiles, particularly in nucleic acid and protein vibrations. The spectral wavenumber range between 1150 and 1240 cm-1 was identified as the classification marker, distinguishing Healthy (noninfected) and infected samples. Machine learning algorithms, with neural networks exhibiting superior performance, successfully classified SARS-CoV-2 variants with a remarkable accuracy of 98.6%. Neural networks were also able to identify and differentiate a small cohort infected with influenza A variants, H1N1 and H3N2, from SARS-CoV-2-infected and Healthy samples. FTIR measurements further show distinct red shifts in vibrational energy and secondary structural alterations in the spike proteins of more transmissible forms of SARS-CoV-2 variants, providing experimental validation of the computational data. This integrated approach presents a promising avenue for rapid and reliable SARS-CoV-2 variant identification, enhancing our understanding of viral evolution and aiding in diagnostic advancements, particularly for an infectious disease with unknown etiology.

Genetic Polymorphism of Interleukin-6 in Asymptomatic and ICU-Admitted COVID-19 Patients in Sulaymaniyah Province, Kurdistan Region of Iraq

Background: The global pandemic of Coronavirus Disease 2019 (COVID-19) has resulted in significant fatality rates. Clinical outcomes for affected individuals range from being asymptomatic to severe illnesses requiring intensive care unit (ICU) admission. Among the various factors contributing to the variation in clinical outcomes, host genetics play a prominent role. Interleukin-6 (IL6), a key player in immune responses, has been identified as having a crucial impact on viral infections, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Specifically, certain variations known as single nucleotide polymorphisms (SNPs) in the IL6 promoter region have been found to significantly influence IL6 expression and the severity of viral infections. Materials and Methods: To explore the relationship between these genetic variations and COVID-19 in asymptomatic and ICU-admitted Kurdish patients, genetic sequencing was performed to determine the genotypes of nine IL6 SNPs. Results: The study findings revealed that although the proportion of the GG genotype of rs1800795 was slightly higher in asymptomatic COVID-19 cases, the difference was not statistically significant (chi2 = 2.666, p = 0.236). Notably, Kurdish patients displayed a uniform genetic makeup (monomorphic) for the dominant alleles of rs2069830 (C), rs142759801 (C), rs2069857 (C), rs2069829 (G), rs2234683 (G), rs13447446 (T), rs527770772 (C), and rs13447445 (C). Furthermore, patients carrying the haplotype GCGGCTCCC were found to have a 0.481-fold higher likelihood of being asymptomatic with COVID-19 (p = 0.016, OR = 0.481). Conclusions: This study demonstrates that the rs1800795 SNP is not statistically associated with COVID-19 at the genotype level. However, the presence of the dominant G allele of rs1800795 in the haplotype was found to be statistically associated with asymptomatic COVID-19 patients.

Evaluation of the PrimeFlow RNA assay as a method of detection of SARS-CoV-2 single and dual Infections

Given the implications of increased transmissibility, virulence, host range, and immune escapes of emerging variants of SARS-CoV-2, developing in vitro models that allow for detection of variants and differences in infection dynamics is important. The objective of this study, was to evaluate the PrimeFlow RNA in-situ assay as a method of detection for multiple strains of SARS-CoV-2. Evaluation of detection and infection statuses included single infections with an Alpha, Delta, or Omicron variants and dual infections with Alpha/Omicron or Delta/Omicron. RNA probes specific for the Spike protein coding region, were designed (omicron or non-omicron specific). SARS-CoV-2 RNA was detected in greater frequency in the Vero E6 and minimally in the fetal deer testicle cell lines by flow cytometry using this approach for viral detection of multiple variants. Most evident in the Vero E6 cells, 24 h post infection both Alpha and Delta predominated over Omicron in dual infections. This is the first report using the PrimeFlow assay for the detection of SARS-CoV-2 at the single-cell level and as a potential model for competition of variants utilizing infection dynamics in cell culture.

Leveraging the immunoinformatics approach for designing the SARS-CoV-2 omicron-specific antigenic cassette of mRNA vaccine

Emergence of SARS-CoV-2 Omicron variant has presented a significant challenge to global health, demanding rapid development of mRNA-based vaccines. The mRNA-guided vaccine platforms offer various advantages over traditional vaccine platforms. The mRNA by nature is a short-lived molecule that guides the cells to manufacture antigenic proteins. In the present work, we have created an omicron spike antigenic protein sequence characterized by base composition analysis, modeling, and docking with the ACE-2 receptor. Further, we predicted the B-cell and T-cell epitopes followed by antigenicity, toxicity, and allergenicity. Finally, the protein was reverse translated, codon-optimized, and encoding mRNA sequence was checked for its stability by predicting the secondary structures. A comprehensive examination of in-silico data revealed 628.2 as a potent antigenic candidate that was finally used in Gemcovac®-OM, a heterologous booster mRNA vaccine for COVID-19.

The influence of SARS-CoV-2 on male reproduction and men's health

BACKGROUND

SARS-CoV-2, the virus responsible for COVID-19, primarily affects the respiratory system by targeting the Angiotensin-converting enzyme 2 (ACE2) receptor and TMPRSS2. However, these receptors are also present in other organs, including the testes, where a higher concentration of ACE2 receptors has been observed. This raises concerns about the potential impact of the virus on male fertility.

AIMS

In this study, we aimed to assess the effects of SARS-CoV-2 on semen parameters by comparing samples during and after infection in the same patients.

MATERIALS & METHOD

The study enrolled 51 individuals who had contracted COVID-19 and analysed various parameters related to sperm quality and quantity, including C-reactive protein, testosterone levels, total sperm concentration, motility and morphology. A comparison was made between these parameters during the initial infection with SARS-CoV-2 and after a 2- and 5-month recovery period.

RESULTS

The results indicated that all of the mentioned parameters were significantly affected during COVID-19 infection (PCR-ct, CRP, WBCs LH, FSH and testosterone levels, p-value = .0001). Furthermore, the study assessed TC, TM and sperm morphology in patients infected with SARS-CoV-2 and found that these parameters were also significantly influenced during the infection, (p-value = .0001; Morphology, p-value = .0004). We observed significant alterations in sperm count and morphology during infection, suggesting a potential negative impact on sperm quality. Additionally, lower hormone levels were observed during COVID-19 infection, possibly due to increased inflammatory cytokines. However, both hormones and inflammation markers returned to normal following recovery. Our findings indicate a statistically significant change in total sperm count, motility and morphology post-infection, which aligns with previous studies. Discussion, COVID-19 have a transient impact on sperm parameters and fertility, emphasizing the importance of further investigation into the long-term implications.

The significance of IFITM3 polymorphism in COVID-19 asymptomatic and ICU admission Kurdish patients

BACKGROUND

The Coronavirus Disease 2019 (COVID-19) is a global pandemic that exhibits a wide range of clinical symptoms, from asymptomatic to critically ill infections that require admission to an intensive care unit (ICU). Interferon-induced transmembrane protein 3 (IFITM3) prevents the viral envelope fusion with the cell membrane, hence playing a crucial role in the immune response. The association between single nucleotide polymorphisms (SNPs) in the IFITM3 gene and the severity of COVID-19 is controversial among various ethnic groups.

METHODS

Seven IFITM3 SNPs were genotyped based on DNA sequencing to investigate the association between these variants and asymptomatic and ICU-admitted COVID-19 patients of the Kurdish nation.

RESULTS

The present study found a significant association between rs12252 and the clinical outcome of COVID-19 (chi2 = 14.83, P = 0.00). The dominant, AA genotype model was significantly associated with a 5.212-fold increased risk of asymptomatic disease (P = 0.000, OR = 5.212). Patients with the GTA haplotypes rs12252, rs34481144, rs7478728 were shown to have a 3.9-fold increased risk of being admitted to the ICU (P = 0.003, OR = 3.9).

CONCLUSION

This study demonstrated that the rs12252 AA genotype is probably associated with asymptomatic COVID-19. In addition, the patients having haplotypes of minor alleles rs12252, rs34481144, and rs7478728 may be associated to COVID-19 ICU admission.

Molecular and clinical significance of FLT3, NPM1, DNMT3A and TP53 mutations in acute myeloid leukemia patients

BACKGROUND

Acute myeloid leukemia (AML) is a type of blood cancer that affects the bone marrow and blood cells. AML is characterized by the rapid growth and accumulation of abnormal white blood cells, known as myeloblasts, which interfere with the production of normal blood cells.

AIMS

The main aim was to determine the relationship between these genetic alterations and the clinico-haematological parameters and prognostic factors with therapy for Iraqi patients with AML.

METHODS

We used Sanger Sequencing to detect the mutations in 76 AML patients. Clinical data of AML patients were retrospectively analysed to compare the prognosis of each gene mutation group.

RESULTS

Somatic mutations were identified in 47.4% of the enrolled patients in a core set of pathogenic genes, including FLT3 (18 patients, 23.7%), DNMT3A (14, 18.4%), NPM1 (11, 14.5%) and TP53 (5, 6.8%). As multiple mutations frequently coexisted in the same patient, we classified patients into 10 further groups. Two novel mutations were detected in FLT3-ITD, with new accession numbers deposited into NCBI GenBank (OP807465 and OP807466). These two novel mutations were computationally analysed and predicted as disease-causing mutations. We found significant differences between patients with and without the detected mutations in disease progression after induction therapy (remission, failure and death; pv = < 0.001) and statistically significant differences were reported in total leukocyte count (pv = < 0.0001).

CONCLUSION

These genes are among the most frequently mutated genes in AML patients. Understanding the molecular and clinical significance of these mutations is important for guiding treatment decisions and predicting patient outcomes.

Genomic surveillance of genes encoding the SARS-CoV-2 spike protein to monitor for emerging variants on Jeju Island, Republic of Korea

Introduction

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been fueled by new variants emerging from circulating strains. Here, we report results from a genomic surveillance study of SARS-CoV-2 on Jeju Island, Republic of Korea, from February 2021 to September 2022.

Methods

A total of 3,585 SARS-CoV-2 positive samples were analyzed by Sanger sequencing of the gene encoding the spike protein before performing phylogenetic analyses.

Results

We found that the Alpha variant (B.1.1.7) was dominant in May 2021 before being replaced by the Delta variant (B.1.617.2) in July 2021, which was dominant until December 2021 before being replaced by the Omicron variant. Mutations in the spike protein, including N440K and G446S, have been proposed to contribute to immune evasion, accelerating the spread of Omicron variants.

Discussion

Our results from Juju Island, Republic of Korea, are consistent with and contribute to global surveillance efforts crucial for identifying new variants of concern of SARS-CoV-2 and for monitoring the transmission dynamics and characteristics of known strains.

Divergent mutations of Delta and Omicron variants: key players behind differential viral attributes across the COVID-19 waves

The third SARS-CoV-2 pandemic wave causing Omicron variant has comparatively higher replication rate and transmissibility than the second wave-causing Delta variant. The exact mechanism behind the differential properties of Delta and Omicron in respect to infectivity and virulence is not properly understood yet. This study reports the analysis of different mutations within the receptor binding domain (RBD) of spike glycoprotein and non-structural protein (nsp) of Delta and Omicron strains. We have used computational studies to evaluate the properties of Delta and Omicron variants in this work. Q498R, Q493R and S375F mutations of RBD showed better docking scores for Omicron compared to Delta variant of SARS-CoV-2, whereas nsp3_L1266I with PARP15 (7OUX), nsp3_L1266I with PARP15 (7OUX), and nsp6_G107 with ISG15 (1Z2M) showed significantly higher docking score. The findings of the present study might be helpful to reveal the probable cause of relatively milder form of COVID-19 disease manifested by Omicron in comparison to Delta variant of SARS-CoV-2 virus.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-023-00823-0.

Genetic polymorphism between the Sorani and Hawrami kurdish populations and COVID-19 outcome

BACKGROUND

Coronavirus Disease 2019 (COVID-19) is a global pandemic, and mortality and clinical consequences vary across countries. One of the factors influencing COVID-19 outcomes is genetic polymorphism. Two Kurdish populations, Sorani and Hawrami, live in the Sulaimani province of the Kurdistan Region of Iraq. It seems Hawrami had a milder COVID-19 outcome. According to previous research conducted on various ethnic groups across the globe, single nucleotide polymorphisms (SNPs) in the interferon-induced transmembrane protein 3 (IFITM3) and interluken-6 (IL6) genes were associated with the severity of COVID-19 in those populations.

METHODS AND RESULTS

We hypothesized that Hawrami may have protective SNPs. So, in this study, we used DNA sequencing to genotype three IFITM3 SNPs and nine IL6 SNPs by DNA sequencing to investigate the association of Sorani and Hawrami population polymorphisms. Genotype AA for the rs12252 SNP in IFITM3 was insignificantly more common in the Sorani group (54% vs. 44%). The Hawrami population showed a higher percentage of the CC genotype of the rs34481144 SNP in the IFITM3 gene (62% vs. 44.3%) and a higher proportion of the non-risky GG genotype of the rs1800795 SNP in the IL6 gene (53.4 vs. 43.3); however, the SNPs were insignificantly associated between the two populations.

CONCLUSIONS

IFITM3 and IL6 SNPs have no statistically significant association between the two Kurdish populations. The decreased proportion of non-risk alleles at rs34481144 and rs1800795 in the Hawrami population may partially support the research hypothesis. However, contrary to our hypothesis, the Sorani group had an insignificantly higher protective variant of the rs12252 SNP.

Identification of SARS CoV-2 Omicron BA.1 and a novel Delta lineage by rapid methods and partial spike protein sequences in Sulaymaniyah Province, Iraq

BACKGROUND

Five variants of concern (VOCs) of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) have been globally recorded including Alpha, Beta, Gamma, Delta, and Omicron. The Omicron variant has outcompeted the other variants including the Delta variant. Molecular screenings of VOCs are important for surveillance, treatment, and vaccination programs. This study aimed to identify VOCs by using rapid inexpensive methods and partial sequencing of the virus's spike gene.

METHODS

Mutation-specific rRT PCR probes were used for both D614G and K417N mutations to potentially discriminate between Delta and Omicron variants. These were followed by sequencing of a fragment of spike gene (748 nucleotides), which covers the most notable VOC mutations in the receptor binding domain of SARS CoV-2.

RESULTS

Rapid methods showed that out of 24 SARS CoV-2 positive samples, 19 carried the N417 mutation, which is present in the Omicron variant. Furthermore, 3 samples carried K417 wildtype, which is present in the Delta variant. Additionally, 2 samples containing both K417 and N417 suggested mixed infections between the two variants. The D614G mutation was present in all samples. Among the 4 samples sequenced, 3 samples carried 13 mutations, which are present in Omicron BA.1. The fourth sample contained the two common mutations (T478K and L452R) present in Delta, in addition to two more rare mutations (F456L and F490S), which are not commonly seen in Delta. Our data suggested that both Omicron variant BA.1 and a novel Delta variant might have circulated in this region that needs further investigations.

Identification of three novel DNMT3A mutations with compromising methylation capacity in human acute myeloid leukaemia

BACKGROUND

Acute myeloid leukaemia (AML) is a complex and heterogeneous hematopoietic stem and progenitor cell malignancy characterised by the accumulation of immature blast cells in the bone marrow, blood, and other organs linked to environmental, genetic, and epigenetic factors. Somatic mutations in the gene DNA (cytosine-5)-methyltransferase 3A (DNMT3A; NM_022552.4) are common in AML patients.

METHODS

In this study, we used Sanger sequencing to detect the mutations in the DNMT3A gene in 61 Iraqi AML patients, Hence, the protein function and stability within alterations were identified and analyzed using a variety of computational tools with the goal of determining how these changes affect total protein stability, and then the capacity of methylation was analyzed by methylation specific PCR MSP status at CpG islands.

RESULTS

Three novel mutations in exon 23 of DNMT3A were identified in 14 patients (22.9%; V877I, N879delA, and L888Q). The V877I and L888Q substitutions are caused by heterozygous C2629G > A and C2663T > A mutations, respectively, while frameshift mutation C2635delA caused protein truncation with stop codon N879T*. Methylation was detected in the DNMT3A promoter region in 9 patients carrying DNMT3A mutations (64.28%) by MSP, and we found significant correlations between DNMT3A mutations and promoter methylation (p = 8.52 × 10⁵). In addition, we found a significant overrepresentation of DNMT3A methylation status in patients ≥ 50 years old (p = 0.025).

CONCLUSION

Our findings highlight the importance of studying the effects of DNMT3A methylation alteration in Iraqi populations beyond R882 substitutions in the leukemogenic pathway so that patient treatment can be tailored to prevent therapeutic resistance and relapse.

Disease severity and efficacy of homologous vaccination among patients infected with SARS-CoV-2 Delta or Omicron VOCs, compared to unvaccinated using main biomarkers

From March 2021, various countries including Iraq issued prompted recommendations for increased COVID-19 vaccine protection in individuals especially those at risk of catching the virus (i.e., lifestyle, health sector workers, and chronic diseases). It is critically important to understand the impact of COVID-19 vaccinations with the most commonly used vaccines (Pfizer and AstraZeneca) among populations either on the severity of the disease or the transmissibility of SARS-CoV-2 variants of concern (VOCs) and in sequential waves. This study was conducted to establish the clinical severity of COVID-19 caused by Delta and Omicron SARS-CoV-2 variants among patients who either attended or were admitted to hospitals and to compare the effectiveness of Pfizer and AstraZeneca COVID-19 vaccines (single or double doses) at least to prevent hospitalizations if not eradicating the pandemic. A case-control study was done of 570 hospitalized patients; including 328 COVID-19 confirmed patients (166 males, 160 females) who received homologous vaccinations and 242 unvaccinated patients (128 males, 114 females) during the studied waves. The study showed that unvaccinated COVID-19 patients in both waves had expressed significantly a higher number and longer periods of symptoms than vaccinated ones. Additionally, there was no significant effect of vaccine types, Pfizer and AstraZeneca or vaccine shot numbers on the PCR-Ct in the last (Omicron) wave of the pandemic. However, in the previous (Delta) wave of the pandemic, fully vaccinated (double doses) COVID-19 patients had higher PCR-Ct values. Whether among vaccinated or unvaccinated patients, lower CRP levels recorded during the Omicron wave than that of the Delta wave, and regardless of the vaccine type or shot numbers, there were no significant differences between the two waves. Lower WBCs were observed in patients (vaccinated and unvaccinated) infected with the Delta variant in comparison to those infected with the Omicron variant and without any remarkable effect of the vaccine type or shot numbers. This is the first molecular and investigational study of the Delta variant and circulated Omicron in Iraq, regarding the severity of these two waves of SARS-CoV-2 pandemic and the efficacy of homologous vaccination, indicating the insufficiency of two doses and the demand for booster dose(s) as the most effective way of keeping on the safe-side against SARS-CoV-2.