Autoimmune disorders such as Hashimoto's thyroiditis lack curative treatments, only therapeutic agents that treat symptoms very broadly and dampen the entire immune system, including healthy cells. Cytotoxic T-Lymphocyte Antigen-4 (CTLA-4) is an immune checkpoint receptor expressed on T cells, and in Hashimoto's thyroiditis the overexpression of CTLA-4 on dysfunctional immune cells is a key factor in disease progression. Here, we evaluated CTLA-4 antibody-antigen binding to specifically treat dysfunctional cells. Protein-protein docking identified Cluster 0 as the most stable pose (energy score -334), ChimeraX showed a buried surface area of 2,136 Ų and 1,023 hydrogen bonds, and in vitro assays confirmed binding.