Dual-Expressor Lymphocytes

The Hamad lab discovered a novel lymphocyte, the “X-cell,” which co-expresses TCR and BCR, challenging traditional immune cell classification. In type 1 diabetes, a dominant X Cell clonotype presents a potent autoantigen that binds diabetogenic HLA-DQ8, driving autoreactive CD4 T cell responses and potentially contributing to autoimmunity.