CD45RB Status of CD8 + T Cell Memory Defines T Cell Receptor Affinity and Persistence.

The identity of CD45 isoforms on the T cell surface changes following the activation of naive T cells and impacts intracellular signaling. In this study, we find that the anti-viral memory CD8 ⁺ T pool is unexpectedly comprised of both CD45RB ^hi and CD45RB ^lo populations. Relative to CD45RB ^lo memory T cells, CD45RB ^hi memory T cells have lower affinity and display greater clonal diversity, as well as a persistent CD27 ^hi phenotype. The CD45RB ^hi memory population displays a homeostatic survival advantage in vivo relative to CD45RB ^lo memory, and long-lived high-affinity cells that persisted long term convert from CD45RB ^lo to CD45RB ^hi . Human CD45RO ⁺ memory is comprised of both CD45RB ^hi and CD45RB ^lo populations with distinct phenotypes, and antigen-specific memory to two viruses is predominantly CD45RB ^hi . These data demonstrate that CD45RB status is distinct from the conventional central/effector T cell memory classification and has potential utility for monitoring and characterizing pathogen-specific CD8 ⁺ T cell responses.
Competing Interests: Declaration of Interests The authors declare no competing interests.
(Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)