High-throughput profiling of the T cell receptor delta CDR3 repertoire reveals species-specific patterns in cattle (Bos taurus) and water buffalo(Bubalus bubalis)

gd T cells constitute a substantial proportion of lymphocytes in ruminants, and the diversity of their immune receptors is critical for understanding species-specific immune functions. The complementarity-determining region 3 (CDR3) of the T cell receptor delta chain (TRD) is a key structural determinant of gd T cell antigen recognition; however, systematic comparative analyses of TRD immune repertoire characteristics across different bovine species remain limited. In this study, high-throughput sequencing and comprehensive analysis of the TRD CDR3 immune repertoire were performed in 7 cattle (Bos taurus) and 5 water buffalo (Bubalus bubalis).Collectively, this study provides a systematic characterization of the similarities and differences in the TRD CDR3 immune repertoires of cattle and water buffalo, offering fundamental data and a comparative perspective for understanding the mechanisms shaping gd TCR diversity and their potential immunological functions in high gd T cell species.