SARS-CoV-2 Spike Protein Induces Hemagglutination: Implications for COVID-19 Morbidities and Therapeutics and for Vaccine Adverse Effects

Effects of recombinant SARS-CoV-2 spike protein variants on red blood cells parameters and red blood cell distribution width

We planned a series of experiments to investigate the possible role of spike protein of different SARS-CoV-2 variants in influencing erythrocyte biology. The values of erythrocyte count, hemoglobin, and mean corpuscular hemoglobin (MHC) did not vary across all samples challenged with both concentrations of the four different SARS-CoV-2 recombinant spike proteins. A significant increase in mean corpuscular volume (MCV) was observed with the recombinant SARS-CoV-2 Alpha and Delta spike proteins at both 2 and 20 ng/mL final concentrations. Red blood cell distribution width (RDW) values increased significantly in samples treated with 20 ng/mL of all SARS-CoV-2 recombinant spike proteins and reached the highest values in samples treated with Omicron recombinant spike protein. Blood smear revision evidenced hemagglutination and rouleaux in samples to which recombinant SARS-CoV-2 spike proteins were added, especially in those with Alpha and Delta variants.

Unlocking insights: Navigating COVID-19 challenges and Emulating future pandemic Resilience strategies with strengthening natural immunity

The original COVID-19 vaccines, developed against SARS-CoV-2, initially mitigated hospitalizations. Bivalent vaccine boosters were used widely during 2022-23, but the outbreaks persisted. Despite this, hospitalizations, mortality, and outbreaks involving dominant mutants like Alpha and Delta increased during winters when the population's vitamin D levels were at their lowest. Notably, 75 % of human immune cell/system functions, including post-vaccination adaptive immunity, rely on adequate circulatory vitamin D levels. Consequently, hypovitaminosis compromises innate and adaptive immune responses, heightening susceptibility to infections and complications. COVID-19 vaccines primarily target SARS-CoV-2 Spike proteins, thus offering only a limited protection through antibodies. mRNA vaccines, such as those for COVID-19, fail to generate secretory/mucosal immunity-like IgG responses, rendering them ineffective in halting viral spread. Additionally, mutations in the SARS-CoV-2 binding domain reduce immune recognition by vaccine-derived antibodies, leading to immune evasion by mutant viruses like Omicron variants. Meanwhile, the repeated administration of bivalent boosters intended to enhance efficacy resulted in the immunoparesis of recipients. As a result, relying solely on vaccines for outbreak prevention, it became less effective. Dominant variants exhibit increased affinity to angiotensin-converting enzyme receptor-2, enhancing infectivity but reducing virulence. Meanwhile, spike protein-related viral mutations do not impact the potency of widely available, repurposed early therapies, like vitamin D and ivermectin. With the re-emergence of COVID-19 and impending coronaviral pandemics, regulators and health organizations should proactively consider approval and strategic use of cost-effective adjunct therapies mentioned above to counter the loss of vaccine efficacy against emerging variants and novel coronaviruses and eliminate vaccine- and anti-viral agents-related serious adverse effects. Timely implementation of these strategies could reduce morbidity, mortality, and healthcare costs and provide a rational approach to address future epidemics and pandemics. This perspective critically reviews relevant literature, providing insights, justifications, and viewpoints into how the scientific community and health authorities can leverage this knowledge cost-effectively.

COVID-19 vaccine adverse events: Evaluating the pathophysiology with an emphasis on sulfur metabolism and endotheliopathy

In this narrative review, we assess the pathophysiology of severe adverse events that presented after vaccination with DNA and mRNA vaccines against COVID-19. The focus is on the perspective of an undersulfated and degraded glycocalyx, considering its impact on immunomodulation, inflammatory responses, coagulation and oxidative stress. The paper explores various factors that lead to glutathione and inorganic sulfate depletion and their subsequent effect on glycocalyx sulfation and other metabolites, including hormones. Components of COVID-19 vaccines, such as DNA and mRNA material, spike protein antigen and lipid nanoparticles, are involved in possible cytotoxic effects. The common thread connecting these adverse events is endotheliopathy or glycocalyx degradation, caused by depleted glutathione and inorganic sulfate levels, shear stress from circulating nanoparticles, aggregation and formation of protein coronas; leading to imbalanced immune responses and chronic release of pro-inflammatory cytokines, ultimately resulting in oxidative stress and systemic inflammatory response syndrome. By understanding the underlying pathophysiology of severe adverse events, better treatment options can be explored.

Human red blood cells express the RNA sensor TLR7

Red blood cells (RBCs) express the nucleic acid-binding toll-like receptor 9 (TLR9) and bind CpG-containing DNA. However, whether human RBCs express other nucleic acid-binding TLRs is unknown. Here we show that human RBCs express the RNA sensor TLR7. TLR7 is present on the red cell membrane and is associated with the RBC membrane protein Band 3. In patients with SARS-CoV2-associated sepsis, TLR7-Band 3 interactions in the RBC membrane are increased when compared with healthy controls. In vitro, RBCs bind synthetic ssRNA and RNA from ssRNA viruses. Thus, RBCs may serve as a previously unrecognized sink for exogenous RNA, expanding the repertoire of non-gas exchanging functions performed by RBCs.

Reduction of hemagglutination induced by a SARS-CoV-2 spike protein fragment using an amyloid-binding benzothiazole amphiphile

COVID-19 infection is associated with a variety of vascular occlusive morbidities. However, a comprehensive understanding of how this virus can induce vascular complications remains lacking. Here, we show that a peptide fragment of SARS-CoV-2 spike protein, S192 (sequence 192-211), is capable of forming amyloid-like aggregates that can induce agglutination of red blood cells, which was not observed with low- and non-aggregated S192 peptide. We subsequently screened eight amyloid-binding molecules and identified BAM1-EG6, a benzothiazole amphiphile, as a promising candidate capable of binding to aggregated S192 and partially inhibiting its agglutination activity. These results provide new insight into a potential molecular mechanism for the capability of spike protein metabolites to contribute to COVID-19-related blood complications and suggest a new therapeutic approach for combating microvascular morbidities in COVID-19 patients.

Increased Age-Adjusted Cancer Mortality After the Third mRNA-Lipid Nanoparticle Vaccine Dose During the COVID-19 Pandemic in Japan

During the COVID-19 pandemic, excess deaths including cancer have become a concern in Japan, which has a rapidly aging population. Thus, this study aimed to evaluate how age-adjusted mortality rates (AMRs) for different types of cancer in Japan changed during the COVID-19 pandemic (2020-2022). Official statistics from Japan were used to compare observed annual and monthly AMRs with predicted rates based on pre-pandemic (2010-2019) figures using logistic regression analysis. No significant excess mortality was observed during the first year of the pandemic (2020). However, some excess cancer mortalities were observed in 2021 after mass vaccination with the first and second vaccine doses, and significant excess mortalities were observed for all cancers and some specific types of cancer (including ovarian cancer, leukemia, prostate cancer, lip/oral/pharyngeal cancer, pancreatic cancer, and breast cancer) after mass vaccination with the third dose in 2022. AMRs for the four cancers with the most deaths (lung, colorectal, stomach, and liver) showed a decreasing trend until the first year of the pandemic in 2020, but the rate of decrease slowed in 2021 and 2022. This study discusses possible explanations for these increases in age-adjusted cancer mortality rates.

Increased von Willebrand and Factor VIII plasma levels in gynecologic patients with Post-Acute-COVID-Sequela (PASC)/Long COVID

Up to 30 % of COVID-infected patients may develop post-acute sequelae of COVID-19 (PASC), also known as Long COVID (LC), a syndrome characterized by a variety of debilitating symptoms lasting for more than 3 months after the acute infection. While the pathophysiological mechanisms behind PASC/LC are not completely understood, growing evidence suggests that an important component of this syndrome may be related to persistent microvascular inflammation causing clumping/clotting of red blood cells and platelets and thrombotic complications. We retrospectively evaluated the plasma levels of von Willebrand factor (VWF), Factor VIII and D-dimer in 10 gynecologic patients (60 % with an endometrial or ovarian cancer diagnosis) affected by PASC/LC vs 5 control patients (60 % harboring endometrial or ovarian tumors). We found elevated VWF and Factor VIII levels in all 10 PASC/LC patients (means of 254 % and 229 %, respectively) vs none of the 5 randomly selected cancer control patients (means of 108 % and 95 %, respectively), p = 0.0046 and p < 0.0001, respectively. In contrast, no significant difference was noted in the levels of D-dimer in PASC/LC. Importantly, abnormally elevated VWF and Factor VIII levels were found to persist for at least 2 years in patients with Long COVID symptoms. VWF and Factor VIII but not D-dimer levels are significantly elevated in the plasma of PASC/LC cancer patients. Abnormally and persistently elevated VWF and Factor VIII levels may represent the results of persistent microvascular damage (i.e., spike-induced endotheliosis) and may be biomarkers of persistent inflammation in gynecologic patients with PASC/LC.

COVID-19 impairs oxygen delivery by altering red blood cell hematological, hemorheological, and oxygen transport properties

Introduction: Coronavirus disease 2019 (COVID-19) is characterized by impaired oxygen (O2) homeostasis, including O2 sensing, uptake, transport/delivery, and consumption. Red blood cells (RBCs) are central to maintaining O2 homeostasis and undergo direct exposure to coronavirus in vivo. We thus hypothesized that COVID-19 alters RBC properties relevant to O2 homeostasis, including the hematological profile, Hb O2 transport characteristics, rheology, and the hypoxic vasodilatory (HVD) reflex. Methods: RBCs from 18 hospitalized COVID-19 subjects and 20 healthy controls were analyzed as follows: (i) clinical hematological parameters (complete blood count; hematology analyzer); (ii) O2 dissociation curves (p50, Hill number, and Bohr plot; Hemox-Analyzer); (iii) rheological properties (osmotic fragility, deformability, and aggregation; laser-assisted optical rotational cell analyzer (LORRCA) ektacytometry); and (iv) vasoactivity (the RBC HVD; vascular ring bioassay). Results: Compared to age- and gender-matched healthy controls, COVID-19 subjects demonstrated 1) significant hematological differences (increased WBC count-with a higher percentage of neutrophils); RBC distribution width (RDW); and reduced hematocrit (HCT), Hb concentration, mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration (MCHC); 2) impaired O2-carrying capacity and O2 capacitance (resulting from anemia) without difference in p50 or Hb-O2 cooperativity; 3) compromised regulation of RBC volume (altered osmotic fragility); 4) reduced RBC deformability; 5) accelerated RBC aggregation kinetics; and (6) no change in the RBC HVD reflex. Discussion: When considered collectively, homeostatic compensation for these RBC impairments requires that the cardiac output in the COVID cohort would need to increase by ∼135% to maintain O2 delivery similar to that in the control cohort. Additionally, the COVID-19 disease RBC properties were found to be exaggerated in blood-type O hospitalized COVID-19 subjects compared to blood-type A. These data indicate that altered RBC features in hospitalized COVID-19 subjects burden the cardiovascular system to maintain O2 delivery homeostasis, which appears exaggerated by blood type (more pronounced with blood-type O) and likely plays a role in disease pathogenesis.

Generation and Characterization of Monoclonal Antibodies against Swine Acute Diarrhea Syndrome Coronavirus Spike Protein

Swine acute diarrhea syndrome coronavirus (SADS-CoV), a member of the family Coronaviridae and the genus Alphacoronavirus, primarily affects piglets under 7 days old, causing symptoms such as diarrhea, vomiting, and dehydration. It has the potential to infect human primary and passaged cells in vitro, indicating a potential risk of zoonotic transmission. In this study, we successfully generated and purified six monoclonal antibodies (mAbs) specifically targeting the spike protein of SADS-CoV, whose epitope were demonstrated specificity to the S1A or S1B region by immunofluorescence assay and enzyme-linked immunosorbent assay. Three of these mAbs were capable of neutralizing SADS-CoV infection on HeLa-R19 and A549. Furthermore, we observed that SADS-CoV induced the agglutination of erythrocytes from both humans and rats, and the hemagglutination inhibition capacity and antigen-antibody binding capacity of the antibodies were assessed. Our study reveals that mAbs specifically targeting the S1A domain demonstrated notable efficacy in suppressing the hemagglutination phenomenon induced by SADS-CoV. This finding represents the first instance of narrowing down the protein region responsible for SADS-CoV-mediated hemagglutination to the S1A domain, and reveals that the cell attachment domains S1A and S1B are the main targets of neutralizing antibodies.

Autoimmune inflammatory reactions triggered by the COVID-19 genetic vaccines in terminally differentiated tissues

As a result of the spread of SARS-CoV-2, a global pandemic was declared. Indiscriminate COVID-19 vaccination has been extended to include age groups and naturally immune people with minimal danger of suffering serious complications due to COVID-19. Solid immuno-histopathological evidence demonstrates that the COVID-19 genetic vaccines can display a wide distribution within the body, affecting tissues that are terminally differentiated and far away from the injection site. These include the heart and brain, which may incur in situ production of spike protein eliciting a strong autoimmunological inflammatory response. Due to the fact that every human cell which synthesises non-self antigens, inevitably becomes the target of the immune system, and since the human body is not a strictly compartmentalised system, accurate pharmacokinetic and pharmacodynamic studies are needed in order to determine precisely which tissues can be harmed. Therefore, our article aims to draw the attention of the scientific and regulatory communities to the critical need for biodistribution studies for the genetic vaccines against COVID-19, as well as for rational harm-benefit assessments by age group.