title: TRP expression pattern and the functional importance of TRPC3 in primary human T-cells.
abstract: TRP proteins form ion channels which are activated following receptor stimulation. In T-cell lines, expression data of TRP proteins have been published. However, almost no data about TRP expression is available in primary human T-cells. Using RT-PCR and quantitative RT-PCR, we compare the expression of TRP mRNA in 1) human peripheral blood lymphocytes, which are a mix of mostly mono-nuclear blood lymphocytes but contain other leucocytes, 2) a pure human CD4+ T-helper cell population in the resting (=naïve) and activated (=effector) state, and 3) two commonly used CD4+ Jurkat T-cell lines, E6-1 and parental. To mimic physiological cell stimulation, we analyzed TRP expression in primary human cells in a quantitative way over several days following formation of an immunological synapse through stimulation with antibody-coated beads. The TRP expression profile of primary human T-cells was significantly different from Jurkat T-cells. Among the TRP mRNAs of the TRPC, TRPM, and TRPV family, we found consistent expression of TRPC1, TRPC3, TRPV1, TRPM2, and TRPM7 in primary human CD4+ T-cells of all analyzed blood donors. Among these, TRPC3 and TRPM2 were strongly up-regulated following stimulation, but with different kinetics. We found that TRPC3 modulates Ca²+-dependent proliferation of primary CD4+ T-cells indicating that TRPC3 may be involved in Ca²+ homeostasis in T-cells besides the well-established STIM and ORAI proteins which are responsible for store-operated Ca²+ entry.
authors.affiliation: Department of Biophysics, Gebäude 58, University of the Saarland, D-66421 Homburg/Saar, Germany.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Wenning
authors.forename: Katherina
authors.initials: K
authors.lastname: Neblung
authors.forename: Bettina
authors.initials: B
authors.lastname: Strauss
authors.forename: Melodie-Jo
authors.initials: MJ
authors.lastname: Wolfs
authors.forename: Anne
authors.initials: A
authors.lastname: Sappok
authors.forename: Markus
authors.initials: M
authors.lastname: Hoth
authors.forename: Eva C
authors.initials: EC
authors.lastname: Schwarz
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D015536:Down-Regulation; D005786:Gene Expression Regulation; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050052:TRPC Cation Channels / Q000235:genetics* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D050052:TRPC Cation Channels; C104603:TRPC3 cation channel; D002118:Calcium