Biology subjects

Erickson, S. A.

Publications and source records attributed to Erickson, S. A..

4 recordsLinked to original sources

bioRxiv2025

In Vivo Evolution of Monoclonal Antibody CR3022 to Achieve Cross-Neutralization of SARS-CoV-2 and Implications for Vaccine Strategies Against SARS-Related Viruses

The epitope that monoclonal CR3022 binds to represents a promising target for broad protection against a wide range of human and zoonotic coronaviruses. We developed a powerful model to evaluate antibody affinity maturation in vivo using immunoglobulin (Ig)-humanized mice that express the predicted germline heavy chain of antibody CR3022. SARS-CoV/SARS-CoV-2 sequential immunization led to the convergent evolution of the germline CR3022 through somatic hypermutation (SHM) that resembled the affinity-matured CR3022 from a human, but now also adapted to key variants and divergent sarbecoviruses. While simple prime-boost strategies drove CR3022-epitope targeting, an intensive vaccination protocol elicited dominant responses to other epitopes. X-ray crystal structures revealed that SARS-CoV-2-neutralizing CR3022-like antibodies exhibit enhanced affinity by increasing polar and electrostatic interactions. Overall, these findings show CR3022-like clones can be readily adapted through SHM to increase breadth and potency to sarbecoviruses by relatively minor shifts in affinity with appropriate vaccination strategies.

immunology↗

bioRxiv2023

The endogenous Mtv8 locus and the immunoglobulin repertoire

The vast diversity of mammalian adaptive antigen receptors allows for robust and efficient immune responses against a wide number of pathogens. The antigen receptor repertoire is built during the recombination and hypermutation of B and T cell receptor (BCR, TCR) loci. V(D)J recombination rearranges these antigen receptor loci, which are organized as an array of separate V, (D), and J gene segments. Transcription activation at the recombining locus leads to changes in the local three-dimensional architecture, which subsequently contributes to which gene segments are utilized for recombination. The endogenous retrovirus (ERV) mouse mammary tumor provirus 8 (Mtv8) resides on mouse chromosome 6 interposed within the large array of light chain kappa V gene segments. As ERVs contribute to changes in genomic architecture by driving high levels of transcription of neighboring genes, it was suggested that Mtv8 could influence the BCR repertoire. We generated Mtv8-deficient mice to determine if the ERV influences V(D)J recombination to test this possibility. We find that Mtv8 does not influence the BCR repertoire.

immunology↗

bioRxiv2022

Site of vulnerability on SARS-CoV-2 spike induces broadly protective antibody to antigenically distinct omicron SARS-CoV-2 subvariants

The rapid evolution of SARS-CoV-2 Omicron variants has emphasized the need to identify antibodies with broad neutralizing capabilities to inform future monoclonal therapies and vaccination strategies. Herein, we identify S728-1157, a broadly neutralizing antibody (bnAb) targeting the receptor-binding site (RBS) and derived from an individual previously infected with SARS-CoV-2 prior to the spread of variants of concern (VOCs). S728-1157 demonstrates broad cross-neutralization of all dominant variants including D614G, Beta, Delta, Kappa, Mu, and Omicron (BA.1/BA.2/BA.2.75/BA.4/BA.5/BL.1). Furthermore, it protected hamsters against in vivo challenges with wildtype, Delta, and BA.1 viruses. Structural analysis reveals that this antibody targets a class 1 epitope via multiple hydrophobic and polar interactions with its CDR-H3, in addition to common class 1 motifs in CDR-H1/CDR-H2. Importantly, this epitope is more readily accessible in the open and prefusion state, or in the hexaproline (6P)-stabilized spike constructs, as compared to diproline (2P) constructs. Overall, S728-1157 demonstrates broad therapeutic potential, and may inform target-driven vaccine design against future SARS-CoV-2 variants.

immunology↗

bioRxiv2021

Optimized immunoglobulin knock-ins using Cas9 reveal peritoneal B cell lineage relationships in vivo

Immunoglobulin (Ig) knock-in mice are valuable tools in basic and translational immunological research. Here we present "Speed-Ig," a rapid Cas9-based method for generating Ig knock-in mouse lines with high on-target integration rates at both heavy and light chain alleles. With standardized target sites and promoter regions, Speed-Ig mice can be used for comparative studies of B cell biology and vaccine optimization in vivo. We used Speed-Ig to create panels of mice with Ig pairs derived from B-1a, B-1b, and B-2 cells. Surprisingly, B-1b and B-2 Ig pairs drove both B-1b and B-2 phenotypes, suggesting a previously unknown lineage relationship between these subsets. We then confirmed the B-1:B-2 relationship with transcription factor reporter lines and through adoptive cell transfer experiments. In summary, our Ig knock-in approach facilitated the discovery of previously unappreciated aspect of innate-like B cell biology.

immunology↗