TY - JOUR A1 - Herrmann, Thomas A1 - Karunakaran, Mohindar M. T1 - The Vγ9Vδ2 T cell antigen receptor and butyrophilin-3 A1: models of interaction, the possibility of co-evolution, and the case of dendritic epidermal T cells N2 - Most circulating human gamma delta T cells are Vγ9Vδ2 T cells. Their hallmark is the expression of T cell antigen receptors (TCR) whose γ-chains show a Vγ9-JP (Vγ2-Jγ1.2) rearrangement and are paired with Vδ2-containing δ-chains, a dominantTCR configuration, which until recently seemed to occur in primates only. Vγ9Vδ2 T cells respond to phosphoantigens (PAg) such as (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), which is produced by many pathogens and isopentenyl pyrophosphate (IPP), which accumulates in certain tumors or cells treated with aminobisphosphonates such as zoledronate. A prerequisite for PAg-induced activation is the contact of Vγ9Vδ2 T cells with cells expressing butyrophilin-3 A1 (BTN3A1). We will first critically review models of how BTN3 might act in PAg-mediated Vγ9Vδ2 T cell activation and then address putative co-evolution of Vγ9, Vδ2, and BTN3 genes. In those rodent and lagomorphs used as animal models, all three genes are lost but a data-base analysis showed that they emerged together with placental mammals. A strong concomitant conservation of functional Vγ9, Vδ2, and BTN3 genes in other species suggests co-evolution of these three genes. A detailed analysis was performed for the new world camelid alpaca (Vicugna pacos). It provides an excellent candidate for a non-primate species with presumably functional Vγ9Vδ2 T cells since TCR rearrangements share features characteristic for PAg-reactive primate Vγ9Vδ2 TCR and proposed PAg-binding sites of BTN3A1 have been conserved. Finally, we analyze the possible functional relationship between the butyrophilin-family member Skint1 and the γδTCR-V genes used by murine dendritic epithelialT cells (DETC). Among placental mammals, we identify five rodents, the cow, a bat, and the cape golden mole as the only species concomitantly possessing potentially functional homologs of murineVγ3,Vδ4 genes, and Skint1 gene and suggest to search for DETC like cells in these species. KW - γδ T cells KW - Vγ9Vδ2 T cell KW - phosphoantigen KW - BTN3 KW - alpaca KW - co-evolution KW - DETC KW - Skint1 Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111141 ER - TY - JOUR A1 - Herrmann, Thomas A1 - Karunakaran, Mohindar M. T1 - Butyrophilins: γδ T cell receptor ligands, immunomodulators and more JF - Frontiers in Immunology N2 - Butyrophilins (BTN) are relatives of the B7 family (e.g., CD80, PD-L1). They fulfill a wide range of functions including immunomodulation and bind to various receptors such as the γδ T cell receptor (γδTCR) and small molecules. One intensively studied molecule is BTN3A1, which binds via its cytoplasmic B30.2 domain, metabolites of isoprenoid synthesis, designated as phosphoantigen (PAg), The enrichment of PAgs in tumors or infected cells is sensed by Vγ9Vδ2 T cells, leading to the proliferation and execution of effector functions to remove these cells. This article discusses the contribution of BTNs, the related BTNL molecules and SKINT1 to the development, activation, and homeostasis of γδ T cells and their immunomodulatory potential, which makes them interesting targets for therapeutic intervention. KW - butyrophilin KW - immune therapy KW - T cell receptor KW - γδ T cell KW - BTN3A1 KW - BTN2A1 KW - phosphoantigen KW - tumor Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265944 SN - 1664-3224 VL - 13 ER - TY - JOUR A1 - Herrmann, Thomas A1 - Fichtner, Alina Suzann A1 - Karunakaran, Mohindar Murugesh T1 - An Update on the Molecular Basis of Phosphoantigen Recognition by Vγ9Vδ2 T Cells JF - Cells N2 - About 1–5% of human blood T cells are Vγ9Vδ2 T cells. Their hallmark is the expression of T cell antigen receptors (TCR) whose γ-chains contain a rearrangement of Vγ9 with JP (TRGV9JP or Vγ2Jγ1.2) and are paired with Vδ2 (TRDV2)-containing δ-chains. These TCRs respond to phosphoantigens (PAg) such as (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), which is found in many pathogens, and isopentenyl pyrophosphate (IPP), which accumulates in certain tumors or cells treated with aminobisphosphonates such as zoledronate. Until recently, these cells were believed to be restricted to primates, while no such cells are found in rodents. The identification of three genes pivotal for PAg recognition encoding for Vγ9, Vδ2, and butyrophilin (BTN) 3 in various non-primate species identified candidate species possessing PAg-reactive Vγ9Vδ2 T cells. Here, we review the current knowledge of the molecular basis of PAg recognition. This not only includes human Vγ9Vδ2 T cells and the recent discovery of BTN2A1 as Vγ9-binding protein mandatory for the PAg response but also insights gained from the identification of functional PAg-reactive Vγ9Vδ2 T cells and BTN3 in the alpaca and phylogenetic comparisons. Finally, we discuss models of the molecular basis of PAg recognition and implications for the development of transgenic mouse models for PAg-reactive Vγ9Vδ2 T cells. KW - γδ T cell KW - phosphoantigen KW - BTN KW - butyrophilin 3 KW - butyrophilin 2A1 KW - evolution KW - alpaca KW - human Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-207937 SN - 2073-4409 VL - 9 IS - 6 ER -