CXCR5+ CCR7 CD8 T cells are early effector memory cells that infiltrate tonsil B cell follicles

MF Quigley, VD Gonzalez, A Granath… - European journal of …, 2007 - Wiley Online Library
MF Quigley, VD Gonzalez, A Granath, J Andersson, JK Sandberg
European journal of immunology, 2007Wiley Online Library
Naive and central memory CD8 T cells use CCR7 to recirculate through T cell zones of
secondary lymphoid organs where they can encounter antigen. Here we describe a subset
of human CD8 T cells expressing CXCR5 which enables homing in response to CXCL13
produced within B cell follicles. CXCR5+ CD8 T cells were found in tonsil B cell follicles, and
isolated cells migrated towards CXCL13 in vitro. They expressed CD27, CD28, CD45RO,
CD69, and were CD7low, and produced IFN‐γ and granzyme A but lacked perforin, a …
Abstract
Naive and central memory CD8 T cells use CCR7 to recirculate through T cell zones of secondary lymphoid organs where they can encounter antigen. Here we describe a subset of human CD8 T cells expressing CXCR5 which enables homing in response to CXCL13 produced within B cell follicles. CXCR5+ CD8 T cells were found in tonsil B cell follicles, and isolated cells migrated towards CXCL13 in vitro. They expressed CD27, CD28, CD45RO, CD69, and were CD7low, and produced IFN‐γ and granzyme A but lacked perforin, a functional profile suggesting that these cells are early effector memory cells in the context of contemporary T cell differentiation models. Receptors important in the interaction with B cells, including CD70, OX40 and ICOS, were induced upon activation, and CXCR5+ CD8 T cells could to some extent support survival and IgG production in tonsil B cells. Furthermore, CXCR5+ CD8 T cells expressed CCR5 but no CCR7, suggesting a migration pattern distinct from that of follicular CD4 T cells. The finding that a subset of early effector memory CD8 T cells use CXCR5 to locate to B cell follicles indicates that MHC class I‐restricted CD8 T cells are part of the follicular T cell population.
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