title: Abundance of follicular helper T cells in Peyer's patches is modulated by CD155.
abstract: The secondary humoral immune response is characterized by plasma B cells secreting isotype-switched and affinity-matured antibodies. The efficient generation of plasma B cells in the GC depends on the presence of follicular helper T (T(FH)) cells, a cell type thought to arise from naive CD4-positive T cells by a hitherto unresolved differentiation pathway. Mice deficient for CD155, an adhesion receptor of the immunoglobulin superfamily, are impaired to mount a secondary humoral immune response upon oral administration of antigen, while the primary IgM response is unaffected. Here, we show that mice lacking CD155 harbor significantly reduced numbers of T(FH) cells in their Peyer's patches. This was paralleled by a decreased frequency of T(FH) cells in the GC. Moreover, the CD155 ligand CD226, which is involved in T-cell activation, is down-regulated during T(FH) cell differentiation, resulting in a complete absence of CD226 on those T(FH) cells residing in the GC. Concurrently, the expression of TIGIT/WUCAM, a newly discovered CD155 ligand, is induced in T(FH) cells. Thus, these cells replace an activating by a putative inhibitory CD155-binding partner during their differentiation.
authors.affiliation: Institute of Immunology, Hannover Medical School, Hannover, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Seth
authors.forename: Inga
authors.initials: I
authors.lastname: Ravens
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kremmer
authors.forename: Michael K
authors.initials: MK
authors.lastname: Maier
authors.forename: Usriansyah
authors.initials: U
authors.lastname: Hadis
authors.forename: Svenja
authors.initials: S
authors.lastname: Hardtke
authors.forename: Reinhold
authors.initials: R
authors.lastname: Förster
authors.forename: Günter
authors.initials: G
authors.lastname: Bernhardt
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D018858:Germinal Center / Q000166:cytology / Q000276:immunology; D056747:Immunomodulation / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology*; D011971:Receptors, Immunologic / Q000276:immunology; D011991:Receptors, Virus / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology / Q000276:immunology*; D000098862:T Lineage-Specific Activation Antigen 1
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000098862:T Lineage-Specific Activation Antigen 1; D011971:Receptors, Immunologic; D011991:Receptors, Virus; C066100:poliovirus receptor