Murine monoclonal antibody 26 raised against tetanus toxoid cross-reacts with beta2-glycoprotein I: its characteristics and role in molecular mimicry

Antiphospholipid syndrome in the era of COVID-19 - Two sides of a coin

In addition to the respiratory symptoms associated with COVID-19, the disease has consistently been linked to many autoimmune diseases such as systemic lupus erythematous and antiphospholipid syndrome (APS). APS in particular was of paramount significance due to its devastating clinical sequela. In fact, the hypercoagulable state seen in patients with acute COVID-19 and the critical role of anticoagulant treatment in affected individuals shed light on the possible relatedness between APS and COVID-19. Moreover, the role of autoimmunity in the assumed association is not less important especially with the accumulated data available regarding the autoimmunity-triggering effect of SARS-CoV-2 infection. This is furtherly strengthened at the time patients with COVID-19 manifested antiphospholipid antibodies of different types following infection. Additionally, the severe form of the APS spectrum, catastrophic APS (CAPS), was shown to have overlapping characteristics with severe COVID-19 such as cytokine storm and multi-organ failure. Interestingly, COVID vaccine-induced autoimmune phenomena described in the medical literature have pointed to an association with APS. Whether the antiphospholipid antibodies were present or de novo, COVID vaccine-induced vascular thrombosis in certain individuals necessitates further investigations regarding the possible mechanisms involved. In our current paper, we aimed to focus on the associations mentioned, their implications, importance, and consequences.

Evaluation of patients with antiphospholipid syndrome subsequently COVID-19 vaccinations: A retrospective cohort study

The aim of this study is to evaluate development of side effects, thrombotic or obstetric complications in our antiphospholipid syndrome (APS) patient group, after vaccination against coronavirus disease 2019 (COVID-19). A cohort was formed from patients who have previously been followed up with a diagnosis of APS. The patients of the cohort were evaluated retrospectively to find out if they were vaccinated with CoronaVac and/or BNT162b2 vaccines which are being used in our country. To evaluate the side effects seen after the vaccination, the information was collected by the patients in their outpatient appointments or making a phone call. Thirty-five APS patients who had received at least 1 dose of any of the COVID-19 vaccines were included in the study. Median (min-max) number of vaccine doses per patient was 2 (1-3). Eleven patients had a booster dose after primary vaccination. Twenty patients were ever vaccinated with BNT162b2 and 18 with CoronaVac. Among BNT162b2 recipients, 9 (45.0%) and among CoronaVac recipients 15 (42.9%) reported an adverse event after a vaccine administration. The most common adverse events were myalgia and malaise after any dose of both vaccines. No vaccine-related new thrombotic events or APS flares were observed. Our results were comparable with those reported in the literature. Comprehensive large-scale studies are needed for more accurate results on the evaluation of side effects after COVID-19 vaccination in APS patients.

Drug-induced antiphospholipid syndrome: Analysis of from the WHO international database

OBJECTIVE

As with drug-induced lupus, some drugs may induce an antiphospholipid syndrome (APS). With the always growing numbers of new molecules, the list of the liable treatments evolves rapidly. We herein analyzed VigiBase, the international pharmacovigilance database, to identify drugs suspected of inducing APS.

METHODS

All the reported cases associated with "anti-phospholipid syndrome" using the preferred term level of medDRA (dictionary of regulated drug activity) when associated with anti-phospholipid antibodies in VigiBase were analyzed. For each treatment, a Bayesian disproportionality indicator (i.e. information component, IC) was calculated. A drug was significantly associated with APS if the 95% lower-end of the IC credibility interval was positive (IC₀₂₅ > 0). Drugs with potential protopathic bias were excluded.

RESULTS

From 01/11/2000 to 25/07/2021, 790 reports of suspected drug-induced APS were found in VigiBase. After excluding drugs reported by a single country and drugs with protopathic bias, fourteen drugs (n = 359 reports) were associated with APS with an IC_{0 25} > 0. These drugs were hormons: ethinylestradiol-etonogestrel and drospirenone-ethynilestradiol; platelet growth factors: eltrombopag, romiplostim; vaccines: Human Papillomavirus vaccine, hepatitis A and B vaccines and typhoid vaccine; antibiotics: minocycline; nonstreroidal anti-inflammatory: rofecoxib; biotherapy: interferon beta-1-a, etanercept; anti-hypertensive drug: hydralazine; bisphosphonates: alendronic acid and antipsychotic: olanzapine. The mean age at diagnosis of drug-induced APS was 39.2 years [29.3;47.9] and there were 63.5% of female patients. The mean delay from first exposition to drug-induced APS was 19.7 months [4.5; 38.8]. Drug-induced APS was reported as a severe side effect in 66.3% of cases: 8.4% with a life-threatening event and 2.5% of death (n = 9). A third (n = 118, 32.9%) pulmonary embolism events were reported and 4.2% (15) cerebral infarctions. 14.8% (53) cases were associated with a systemic lupus, a sub-analysis without lupus cases showed the same severity of cases.

CONCLUSION

This study identified 14 drugs potentially associated with drug-induced APS that may prove useful in the investigational work-up in any new diagnosis of APS.

TRIAL REGISTRATION NUMBER

NCT03994302.

Dysautonomia Following Tetanus, Diphtheria, and Pertussis Vaccine (Tdap): The First Case of Extreme Cachexia Caused by Autoimmune/Inflammatory Syndrome Induced by Adjuvants (ASIA Syndrome) in a Human

Autoimmune/inflammatory Syndrome Induced by Adjuvants (ASIA; Shoenfeld’s syndrome) comprehends a group of autoimmune conditions that flourish in genetically predisposed individuals, following an external stimulus by the so-called adjuvants. Many adjuvants were described, such as vaccines, aluminum and other metals, silicone, tattoos, among others. Those conditions entail defined diseases, such as sarcoidosis and Sjogren’s syndrome, and generalized complex symptoms, for example, fatigue, sleep disturbance, orthostatic intolerance, and other dysautonomic manifestations. Those complaints were previously associated with autoantibodies against nervous system autonomic receptors, especially antibeta 1 adrenergic receptor antibodies, suggesting the autoimmune component of the condition. Here we report on a case of an 18-year-old woman who presented with extreme cachexia due to severe dysautonomia caused by the ASIA syndrome induced by the tetanus, diphtheria, and pertussis vaccine (Tdap).

Antiphospholipid antibodies and risk of post-COVID-19 vaccination thrombophilia: The straw that breaks the camel's back?

Antiphospholipid antibodies (aPLs), present in 1–5 % of healthy individuals, are associated with the risk of antiphospholipid syndrome (APS), which is the most common form of acquired thrombophilia. APLs may appear following infections or vaccinations and have been reported in patients with COronaVIrus Disease-2019 (COVID-19). However, their association with COVID-19 vaccination is unclear. Notably, a few cases of thrombocytopenia and thrombotic events resembling APS have been reported to develop in recipients of either adenoviral vector- or mRNA-based COVID-19 vaccines.

The aim of this review is therefore to speculate on the plausible role of aPLs in the pathogenesis of these rare adverse events.

Adenoviral vector-based vaccines can bind platelets and induce their destruction in the reticuloendothelial organs. Liposomal mRNA-based vaccines may instead favour activation of coagulation factors and confer a pro-thrombotic phenotype to endothelial cells and platelets. Furthermore, both formulations may trigger a type I interferon response associated with the generation of aPLs. In turn, aPLs may lead to aberrant activation of the immune response with participation of innate immune cells, cytokines and the complement cascade. NETosis, monocyte recruitment and cytokine release may further support endothelial dysfunction and promote platelet aggregation. These considerations suggest that aPLs may represent a risk factor for thrombotic events following COVID-19 vaccination, and deserve further investigations.

Cross-Reactive Effects of Vaccines: Heterologous Immunity between Tetanus and Chlamydia

Vaccines can have heterologous effects on the immune system, i.e., effects other than triggering an immune response against the disease targeted by the vaccine. We investigated whether monoclonal antibodies (mAbs) specific for tetanus could cross-react with Chlamydia and confer heterologous protection against chlamydial infection. The capability of two tetanus-specific mAbs, namely mAb26 and mAb51, to prevent chlamydial infection has been assessed: (i) in vitro, by performing a neutralization assay using human conjunctival epithelial (HCjE) cells infected with Chlamydia trachomatis serovar B, and (ii) in vivo, by using a guinea pig model of Chlamydiacaviae-induced inclusion conjunctivitis. The mAb26 has been superior in comparison with mAb51 in the prevention of chlamydial infection in HCjE cells. The mAb26 has conferred ≈40% inhibition of the infection, compared to less than 5% inhibition in the presence of the mAb51. In vivo, mAb26 significantly diminished ocular pathology intensity in guinea pigs infected with C. caviae compared to either the mAb51-treated or sham-treated guinea pigs. Our data provide insights that tetanus immunization generates antibodies which induce heterologous chlamydial immunity and promote protection beyond the intended target pathogen.

Role of Infectious Diseases in the Antiphospholipid Syndrome (Including Its Catastrophic Variant)

PURPOSE OF REVIEW

The antiphospholipid syndrome (APS) is characterized by the development of thrombotic events and pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). An infectious etiology for this syndrome has been postulated. The present review is aimed to summarize recent evidence about the role of infections and vaccines in the pathogenesis of the APS (including its catastrophic variant).

RECENT FINDINGS

There is an increased risk of developing aPL in various infections, particularly in viral infections. The most frequent infection related to aPL has been hepatitis C virus. These antibodies may be associated with thromboembolic events, including catastrophic APS. There is a link between vaccinations, such as the tetanus toxoid and aPL, due to molecular mimicry between the two molecules. Accumulated evidence supports that the presence of aPL is associated with a variety of infections, including viruses, bacteria, fungi, and parasites, and the main mechanism to explain this correlation is molecular mimicry. Moreover, a link between vaccinations, such as the tetanus toxoid, and APS has also been described.

Autoimmune/inflammatory syndrome induced by adjuvants (Shoenfeld’s syndrome) – An update

Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) has been widely described in many studies conducted thus far. The syndrome incorporates five immune-mediated conditions, all associated with previous exposure to various agents such as vaccines, silicone implants and several others. The emergence of ASIA syndrome is associated with individual genetic predisposition, for instance those carrying HLA-DRB1*01 or HLA-DRB4 and results from exposure to external or endogenous factors triggering autoimmunity. Such factors have been demonstrated as able to induce autoimmunity in both animal models and humans via a variety of proposed mechanisms. In recent years, physicians have become more aware of the existence of ASIA syndrome and the relationship between adjuvants exposure and autoimmunity and more cases are being reported. Accordingly, we have created a registry that includes at present more than 300 ASIA syndrome cases that have been reported by different physicians worldwide, describing various autoimmune conditions induced by diverse adjuvants.

In this review, we have summarized the updated literature on ASIA syndrome and the knowledge accumulated since 2013 in order to elucidate the association between the exposure to various adjuvant agents and its possible clinical manifestations. Furthermore, we especially referred to the relationship between ASIA syndrome and systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS).

Infections and vaccines in the etiology of antiphospholipid syndrome

PURPOSE OF REVIEW

To present scientific evidence supporting the infectious origin for the antiphospholipid syndrome (APS) by molecular mimicry between pathogens, infection and vaccination with β2-glycoprotein I (β2-GPI) molecule.

RECENT FINDINGS

APS is characterized by the presence of pathogenic autoantibodies against β2-GPI. The infection etiology of APS was well established. Likewise, a link between vaccination such as tetanus toxoid may trigger antibodies targeting tetanus toxoid and β2-GPI, due to molecular mimicry between the two molecules. During the years, the pathogenic potential of anti-tetanus toxoid antibodies cross reactive with β2-GPI were found to be pathogenic in animal models, inducing experimental APS.

SUMMARY

Accumulated evidence supports that the presence of anti-β2-GPI antibodies is associated with a history of infections and the main mechanism to explain this correlation is molecular mimicry. The relationship between tetanus toxoid vaccination and APS reveals a novel view on the autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA).

Vaccine model of antiphospholipid syndrome induced by tetanus vaccine

Successful induction of antiphospholipid syndrome (APS) in two different non-autoimmune prone mouse strains, BALB/c and C57BL/6, was achieved by tetanus toxoid (TTd) hyperimmunization using different adjuvants (glycerol or aluminium hydroxide), and different adjuvant pretreatments (glycerol or Complete Freund’s Adjuvant (CFA)). APS had different manifestations of reproductive pathology in BALB/c and C57BL/6 mice: fetal resorption (as a consequence of extreme T-cell activation obtained in the course of pretreatment), and lowering of fecundity (as a consequence of polyclonal B-cell stimulation), respectively. In BALB/c mice fetal resorption coincided with glycerol and CFA pretreatments, while in C57BL/6 mice lowering of fecundity was most obvious in CFA-pretreated mice immunized with TTd in aluminium hydroxide. Both molecular mimicry and polyclonal B-cell activation occur in APS induction, with molecular mimicry effects being dominant in BALB/c mice, and polyclonal cell activation being dominant in C57BL/6 mice. Confirmation of molecular mimicry effects, which in the condition of T-cell stimulation generated fetal resorptions in the BALB/c strain, was achieved by passive infusion of monoclonal antibody (MoAb) T-26 specific for TTd and anti-β2-glycoprotein I obtained after TTd hyperimunization. High polyclonal B-cell activation in C57BL/6 mice prevented fetal resorption but induced fecundity lowering, as was the case in passive administration of MoAb T-26 in this mouse strain. Passive infusion of anti-idiotypic MoAb Y7 into C57BL/6 mice induced fetal resorptions and confirmed the above suggestion on the protective role of polyclonal B-cell stimulation in fetal resorptions.

Induction of APS after TTd hyper-immunization has a different outcome in BALB/c and C57BL/6 mice

PROBLEM

The antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by vascular thrombosis and/or pregnancy complications (lower fecundity and lower litter size), as well as by an increase in anti-β(2) glycoprotein I (β(2) GPI)-specific autoantibody titer. We have investigated how the genetic background of the immune system [T helper (Th) prevalence] and the type of animal model of APS influence the induced pathology.

METHOD OF STUDY

Antiphospholipid syndrome induced by tetanus toxoid (TTd) hyper-immunization and by intravenous application of monoclonal anti-β(2) GPI-specific antibody 26 was compared in C57BL/6 (Th1 prone) and BALB/c (Th2 prone) mice.

RESULTS

Tetanus toxoid hyper-immunization of BALB/c mice led to reduction in fertility, but in C57BL/6 mice a decrease in fecundity occurred. In both cases, pathology was caused by anti-β(2) GPI antibodies, the production of which was adjuvant and strain dependent.

CONCLUSION

We conclude that TTd immunization and i.v. application of monoclonal antibody 26 induced the same reproductive pathology and that the type of pathology is strain dependent.

Engineering filamentous phage carriers to improve focusing of antibody responses against peptides

The filamentous bacteriophage are highly immunogenic particles that can be used as carrier proteins for peptides and presumably other haptens and antigens. Our previous work demonstrated that the antibody response was better focused against a synthetic peptide if it was conjugated to phage as compared to the classical carrier, ovalbumin. We speculated that this was due, in part, to the relatively low surface complexity of the phage. Here, we further investigate the phage as an immunogenic carrier, and the effect reducing its surface complexity has on the antibody response against peptides that are either displayed as recombinant fusions to the phage coat or are chemically conjugated to it. Immunodominant regions of the minor coat protein, pIII, were removed from the phage surface by excising its N1 and N2 domains (Delta3 phage variant), whereas immunodominant epitopes of the major coat protein, pVIII, were altered by reducing the charge of its surface-exposed N-terminal residues (Delta8 phage variant). Immunization of mice revealed that the Delta3 variant was less immunogenic than wild-type (WT) phage, whereas the Delta8 variant was more immunogenic. The immunogenicity of two different peptides was tested in the context of the WT and Delta3 phage in two different forms: (i) as recombinant peptides fused to pVIII, and (ii) as synthetic peptides conjugated to the phage surface. One peptide (MD10) in its recombinant form produced a stronger anti-peptide antibody response fused to the WT carrier compared to the Delta3 phage carrier, and did not elicit a detectable anti-peptide response in its synthetic form conjugated to either phage carrier. This trend was reversed for a different peptide (4E10(L)), which did not produce a detectable anti-peptide antibody response as a recombinant fusion; yet, as a chemical conjugate to Delta3 phage, but not WT phage, it elicited a highly focused anti-peptide antibody response that exceeded the anti-carrier response by approximately 65-fold. The results suggest that focusing of the antibody response against synthetic peptides can be improved by decreasing the antigenic complexity of the phage surface.

Molecular mimicry in systemic lupus erythematosus

Systemic lupus erythematosus is a multi-systemic autoimmune disease distinguished by the presence of various autoantibodies. Like most autoimmune diseases, systemic lupus erythematosus is believed to be induced by a combination of genetic, immunologic, and environmental factors, mainly infectious agents. Molecular mimicry between an infectious antigen and self-components is implicated as a pivotal mechanism by which autoimmune diseases such as systemic lupus erythematosus are triggered. Here we review the current evidence of molecular mimicry between different infectious agents and systemic lupus erythematosus.

The monoclonal antibody 26 raised against tetanus toxoid also recognizes tetanus toxin and β2-glycoprotein I - its binding properties in vitro and potential applications

A murine monoclonal IgG1 antibody, marked as MAb26, specific for tetanus toxoid has been immunochemically characterized. By performing enzyme-linked immunosorbent assays (ELISAs) and western blot analyses, it was demonstrated that MAb26 reacted with tetanus toxoid, tetanus toxin and ?2-glycoprotein I (?2GPI). According to the results, MAb26 recognized the sequential epitope on the tetanus heavy chain. The affinity constant, calculated from Scatchard plots of MAb26 binding to tetanus toxoid, was 1.145?108 M-1 and the measurement of the relative affinity of MAb26 by ELISA using thiocyanate elution showed a significantly higher affinity of MAb26 to the toxoid (p = 0.0012) in comparison to the toxin. Additionally, the reactivity of MAb26 toward the toxoid forms increased when the tetanus toxin was detoxified using 8 mM and higher formaldehyde concentrations. The similarity of the tetanus toxoid to several sera proteins, either at the level of its conformation (IL-1?) or at the level of peptide sequences (?2GPI, laminin) favors its role in autoimmunity by the mechanism of molecular mimicry. As the induction of an autoimmune disease is dependent on the breakdown of tolerance, which could be the result of an overt hyperstimulation, the control of the presence and concentration of self-reactive epitopes in vaccine preparations is a prerequisite. In this study, it was shown that MAb26 can: 1) discriminate between the tetanus toxin and different toxoid forms, which makes it a good candidate for antibody control during vaccine preparation; 2) due to its cross-reactivity with ?2GPI, it could provide information on the presence of a potentially dangerous sequential epitope expressed at the protein surface.