Mohamad Ammar Ayass

Peanut allergies, driven by sensitization to key allergens Ara h1, Ara h2, and Ara h3, present significant health risks, particularly in food processing and consumer settings where accidental exposure is frequent. To mitigate this risk, we developed AYA22AR321, a novel aptamer with selective, high-affinity binding to these allergens (Kd values: 0.5 nM for Ara h1, 14.5 nM for Ara h2, and 6.6 nM for crude peanut extract). Functional assays using RBL-2H3 (rat basophilic leukemia cell line) cells showed that AYA22AR321 significantly reduces IgE-mediated degranulation, indicating its potential to attenuate allergic responses. To translate these findings into practical use, we formulated an allergen-neutralizing spray, FISTOQ, containing AYA22AR321, which effectively neutralized peanut allergens on peanut-butter-contaminated surfaces. Stability tests confirmed that FISTOQ, comprising eco-friendly surfactant and preservative, maintains its allergen-neutralizing efficacy over time. Comprehensive safety assessments, including immunogenicity, cytotoxicity in human PBMCs, and mutagenicity via the Ames test, demonstrated that AYA22AR321 is non-immunogenic, non-cytotoxic, and non-mutagenic. This study establishes AYA22AR321 as a promising, targeted strategy for allergen control, providing a significant advancement in allergen mitigation and food safety for high-risk environments.

Food allergy, particularly peanut allergy (PA), is a growing health concern affecting millions globally. PA can lead to severe reactions, including fatal anaphylaxis. Despite the availability of FDA-approved therapies like Palforzia, a cure remains elusive. Current immunotherapies show promise but lack a definitive cure. This study applies an established computational biology tool to design aptamers targeting Ara h1 and Ara h2. The in silico design aims to streamline the selection process, enabling cost-effective and rapid identification of aptamer candidates. The developed aptamers (AYA22A, including AYA22AR321, AYA22AR211, and AYA22AR524), demonstrated efficacy in inhibiting degranulation of RBL-2H3 cells (rat basophilic leukemia cell line) in vitro. They showed promise in neutralizing peanut allergen-induced immune responses. The selected aptamers inhibited degranulation in RBL-2H3 cells, addressing concerns in raw peanuts. Moreover, these aptamers demonstrated stability and effectiveness in peanut plant seeds and commercial products. Our aptamers exhibited potential in modulating immune responses associated with peanut allergy. They influenced Th1/Th2 balance, indicating a role in cytokine regulation. In vitro studies also showed the aptamers’ impact on immune cell expression and cytokine production, resembling responses observed with established immunotherapies. The findings suggest AYA22A aptamers as a potential therapeutic option for peanut allergy, providing a basis for further in vivo investigations.

Recent strides in immunotherapy have illuminated the crucial role of CTLA-4 and PD-1/PD-L1 pathways in contemporary oncology, presenting both promises and challenges in response rates and adverse effects. This study employs a computational biology tool (in silico approach) to craft aptamers capable of binding to dual receptors, namely, inhibitory CTLA4 and NKG2A, thereby unleashing both T and NK cells and enhancing CD8⁺ T and NK cell functions for tumor cell lysis. Computational analysis highlighted AYA22T-R2-13 with HADDOCK scores of −78.2 ± 10.2 (with CTLA4), −60.0 ± 4.2 (with NKG2A), and −77.5 ± 5.6 (with CD94/NKG2A). Confirmation of aptamer binding to targeted proteins was attained via ELISA and flow cytometry methods. In vitro biological functionality was assessed using lactate dehydrogenase (LDH) cytotoxicity assay. Direct and competitive assays using ELISA and flow cytometry demonstrated the selective binding of AYA22T-R2-13 to CTLA4 and NKG2A proteins, as well as to the cell surface receptors of IL-2-stimulated T cells and NK cells. This binding was inhibited in the presence of competition from CTLA4 or NKG2A proteins. Remarkably, the blockade of CTLA4 or NKG2A by AYA22T-R2-13 augmented human CD8 T cell- and NK cell-mediated tumor cell lysis in vitro. Our findings highlight the precise binding specificity of AYA22T-R2-13 for CTLA4-B7-1/B7-2 (CD80/CD86) or CD94/NKG2A-HLA-E interactions, positioning it as a valuable tool for immune checkpoint blockade aptamer research in murine tumor models. These in vitro studies establish a promising foundation for further enhancing binding capacity and establishing efficacy and safety in animal models. Consequently, our results underscore the potential of AYA22T-R2-13 in cancer immunotherapy, offering high specificity, low toxicity, and the potential for cost-effective production.

Thrombin is a key enzyme involved in blood clotting, and its dysregulation can lead to thrombotic diseases such as stroke, myocardial infarction, and deep vein thrombosis. Thrombin aptamers have the potential to be used as therapeutic agents to prevent or treat thrombotic diseases. Thrombin DNA aptamers developed in our laboratory exhibit high affinity and specificity to thrombin. In vitro assays have demonstrated their efficacy by significantly decreasing Factor II activity and increasing PT and APTT times in both plasma and whole blood. Aptamers AYA1809002 and AYA1809004, the two most potent aptamers, exhibit high affinity for their target, with affinity constants (Kd) of 10 nM and 13 nM, respectively. Furthermore, the in vitro activity of these aptamers displays dose-dependent behavior, highlighting their efficacy in a concentration-dependent manner. In vitro stability assessments reveal that the aptamers remain stable in plasma and whole blood for up to 24 h. This finding is crucial for their potential application in clinical settings. Importantly, the thrombin inhibitory activity of the aptamers can be reversed by employing reverse complement sequences, providing a mechanism to counteract their anticoagulant effects when necessary to avoid excessive bleeding. These thrombin aptamers have been determined to be safe, with no observed mutagenic or immunogenic effects. Overall, these findings highlight the promising characteristics of these newly developed thrombin DNA aptamers, emphasizing their potential for therapeutic applications in the field of anticoagulation therapy. Moreover, the inclusion of an antidote in the coagulation therapy regimen can improve patient safety, ensure greater therapeutic efficacy, and minimize risk during emergency situations.

The continuous emergence of new variants of concern for SARS-CoV-2 has created a challenge for existing therapies. To address this, we developed a series of single-stranded DNA aptamers that not only bind specifically to the trimer S protein of SARS-CoV-2 but also block the interaction between the trimer S protein and ACE2 receptors. The systematic evolution of ligands by exponential enrichment (SELEX) was performed to select the aptamers for SARS-CoV-2 trimer S protein. ELISA-based assay and flow cytometry were performed to test the apatmers’ binding and inhibition of trimer S protein in vitro. Binding affinity was measured using surface plasmon resonance. Significance was determined in Prism 9.0 using the one-way ANOVA test (Dunnett’s multiple comparisons test) or two-way ANOVA test (Tukey’s multiple comparisons test) for comparisons. The p values < 0.05 were considered statistically significant. After 12 rounds of SELEX, eight highly enriched aptamers were able to bind to the trimer S protein of the SARS-CoV-2 Wuhan original strain as well as the trimer S proteins of the Delta, Delta plus, Alpha, Lambda, Mu, and Omicron variants, with affinities in the nM range, while also inhibiting their interaction with ACE2 receptors in Vero E6 cells. Modifications to our best aptamer were made by adding forward and reverse primer sequences and truncation. The modified aptamers AYA2012004_L and AYA2012004_L-M1 showed up to 70% inhibition of the binding of virus-like particles (VLPs) expressing S protein to the ACE2 receptor expressed in HEK293T cells. Our findings imply that the selected aptamers can prevent SARS-CoV-2 from entering host cells and hence suppress the viral infection. In addition, the findings suggest that the selected aptamers might be an innovative therapy for the treatment of COVID-19.

Background: Coronavirus disease 2019 (COVID-19) vaccines are effective at helping protect against severe disease and death from variants; however, incident of breakthrough infection in vaccinated patients has been increased. Therefore, we aimed to assess the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) new variants of concern in the communities and investigate vaccine breakthrough cases on our laboratory (Ayass Bioscience LLC) confirmed detection of COVID-19 variants in Dallas-Fort Worth (DFW), Texas. Methods: Epidemiologic study has been performed at our laboratory. We studied the viral whole-genome sequence and genotyping analysis on 166 symptomatic cases of COVID-19 which were randomly selected from nasal swab positive cases assessed from June 1st to August 30th, 2021, by reverse transcription polymerase chain reaction (RT-PCR) cycle threshold (CT) values. COVID-19 variants were identified to be dominated by B.1.617.2 (89.2%) and followed by AY.3 (1.8%), B.1.1.7 (4.8%), a combination of B.1.526.1 and B.1.617.2 (3%), B.1.621 (0.6%), and P.2 (0.6%). Result: The CT values showed significant difference among the three age groups: 60 years by one-way ANOVA (N1: F (2, 118) =4.96, p=0.009; N2: F (2, 118) =4.95, p=0.009). No significant difference was observed by symptom, status of immunization, or vaccine manufacturer. A two-way ANOVA was performed to examine the effect of gender and variant group (Delta and other variants) on the CT values. The analyses revealed a statistically significant interaction between the effect of gender and variant group (N1, F (1.117) = 3.906, p = 0.05; N2, F (1, 117) = 7.402, p = 0.008). Conclusion: Our study shows that Delta, the dominant variant of COVID-19, is spreading in the communities, and vaccine breakthrough cases occurred in the majority of Delta variant (91%) followed by AY.3 (5%), B.1.1.7 (2%) and 2% of the double variant of B.1.526.1 and B.1.617.2. The incidence of the breakthrough cases was not linked to a specific manufacturer. The CT value is likely to associate with age. This study also supports our laboratory’s ongoing efforts to sequence the SARS-CoV-2 virus from positive patient samples to identify the new viral variants and possible vaccine breakthrough mutations in the community.