TCR repertoire diversification constitutes a foundation for successful immune reconstitution after allogeneic hematopoietic cell transplantation (allo-HCT). Deep TCR Vβ sequencing of 135 serial specimens from a cohort of 35 allo-HCT recipients/donors was performed to dissect posttransplant TCR architecture and dynamics. Paired analysis of clonotypic repertoires showed a minimal overlap with donor expansions. Rarefied and hyperexpanded clonotypic patterns were hallmarks of T cell reconstitution and influenced clinical outcomes. Donor and pretransplant TCR diversity as well as divergence of class I human leukocyte antigen genotypes were major predictors of recipient TCR repertoire recovery. Complementary determining region 3–based specificity spectrum analysis indicated a predominant expansion of pathogen- and tumor-associated clonotypes in the late post–allo-HCT phase, while autoreactive clones were more expanded in the case of graft-versus-host disease occurrence. These findings shed light on post–allo-HCT adaptive immune reconstitution processes and possibly help in tracking alloreactive responses.
Simona Pagliuca, Carmelo Gurnari, Sanghee Hong, Ran Zhao, Sunisa Kongkiatkamon, Laila Terkawi, Misam Zawit, Yihong Guan, Hassan Awada, Ashwin Kishtagari, Cassandra M. Kerr, Thomas LaFramboise, Bhumika J. Patel, Babal K. Jha, Hetty E. Carraway, Valeria Visconte, Navneet S. Majhail, Betty K. Hamilton, Jaroslaw P. Maciejewski