Phage display-based selection of high-affinity recombinant antibodies targeting tetanus toxoid

Despite the availability of effective vaccines, tetanus continues to pose a significant global health challenge, particularly among under-immunized populations. This situation emphasizes the importance of developing improved diagnostic and therapeutic strategies targeting tetanus toxoid, the chemically inactivated form of tetanus neurotoxin. This study aimed to isolate recombinant phage clones expressing single-chain variable fragment (scFv) antibodies specific to tetanus toxoid using phage display technology. This method offers a powerful and scalable alternative to traditional antibody Production techniques. Two human scFv phage libraries, Tomlinson I and Tomlinson J, were propagated in Escherichia coli TG1 cells and subjected to three successive rounds of biopanning against microplate-immobilized tetanus toxoid to enrich specific binders. The selected phage clones were subsequently analyzed for binding specificity and affinity using enzyme-linked immunosorbent assay (ELISA) and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). ELISA results revealed that clones from Library J, particularly clones G and H, exhibited the highest absorbance values at 450 nm (OD₄₅₀), indicating strong and specific binding to tetanus toxoid. These results confirm the efficiency of phage display technology in isolating high-affinity recombinant antibodies against bacterial toxins such as tetanus toxoid. The identified scFv clones can serve as valuable tools in the development of rapid and sensitive diagnostic assays or as potential therapeutic candidates. Overall, this approach represents a promising strategy for enhancing the detection and management of tetanus, particularly in resource-limited or high-risk settings.