title: Memory CD4 T cells that express CXCR5 provide accelerated help to B cells.
abstract: CD4 T cell help for B cells is critical for effective Ab responses. Although many of the molecules involved in helper functions of naive CD4 T cells have been characterized, much less is known about the helper capabilities of memory CD4 T cells, an important consideration for the design of vaccines that aim to prime protective memory CD4 T cells. In this study, we demonstrate that memory CD4 T cells enable B cells to expand more rapidly and class switch earlier than do primary responding CD4 T cells. This accelerated response does not require large numbers of memory cells, and similar numbers of primary responding cells provide less effective help than do memory cells. However, only memory CD4 T cells that express the B cell follicle homing molecule, CXCR5, are able to accelerate the response, suggesting that the rapidity of the Ab response depends on the ability of CD4 memory T cells to migrate quickly toward B cells.
authors.affiliation: Integrated Department of Immunology, Howard Hughes Medical Institute, National Jewish Health, Denver, CO 80206, USA. macleodm@njhealth.org
authors.forename: Megan K L
authors.initials: MK
authors.lastname: MacLeod
authors.forename: Alexandria
authors.initials: A
authors.lastname: David
authors.forename: Amy S
authors.initials: AS
authors.lastname: McKee
authors.forename: Frances
authors.initials: F
authors.lastname: Crawford
authors.forename: John W
authors.initials: JW
authors.lastname: Kappler
authors.forename: Philippa
authors.initials: P
authors.lastname: Marrack
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000637:transplantation; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D005260:Female; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000276:immunology; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology / Q000472:pathogenicity; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D054380:Receptors, CXCR5 / Q000096:biosynthesis* / Q000502:physiology; D016201:Receptors, Lymphocyte Homing / Q000008:administration & dosage / Q000096:biosynthesis / Q000502:physiology; D016192:Resting Phase, Cell Cycle / Q000276:immunology
chemical_list: C513179:CXCR5 protein, mouse; D007074:Immunoglobulin G; D054380:Receptors, CXCR5; D016201:Receptors, Lymphocyte Homing