TY - JOUR
T1 - Human CD3γ, but not CD3δ, haploinsufficiency differentially impairs γδ versus αβ surface TCR expression
AU - Muñoz-Ruiz, Miguel
AU - Pérez-Flores, Verónica
AU - Garcillán, Beatriz
AU - Guardo, Alberto C.
AU - Mazariegos, Marina S.
AU - Takada, Hidetoshi
AU - Allende, Luis M.
AU - Kilic, Sara S.
AU - Sanal, Ozden
AU - Roifman, Chaim M.
AU - López-Granados, Eduardo
AU - Recio, María J.
AU - Martínez-Naves, Eduardo
AU - Fernández-Malavé, Edgar
AU - Regueiro, José R.
N1 - Funding Information:
Bent Rubin provided continuous support and comments. Elena M. Busto, Joaquín Caspistegui, Juana Gil, Miguel Fdez-Arquero and Jesús Reiné provided technical help. Brenda Reid, Sandra Mendonca and Linda Pires from the Hospital for Sick Children in Toronto are greatefully acknowledged for their excellent collaboration to obtain and ship blood samples. This work was supported by grants from the Ministerio de Educación (BFU2005-01738/ BMC and SAF2011-24235), Comunidad Autónoma de Madrid (CAM) (GR/SAL/ 0570/2004 and S2011/BMD-2316), Fundación Lair, Instituto de Salud Carlos III (ISCIII PI080921, PI060057 and RIER RD08-0075-0002) and the Hospital 12 de Octubre Health Research Institute. MMR was supported by the Universidad Complutense de Madrid and ISCIII and VPF was supported by Ministerio de Educación.
PY - 2013/1/21
Y1 - 2013/1/21
N2 - Background: The T cell antigen receptors (TCR) of αβ and γδ T lymphocytes are believed to assemble in a similar fashion in humans. Firstly, αβ or γδ TCR chains incorporate a CD3δε dimer, then a CD3γε dimer and finally a ζζ homodimer, resulting in TCR complexes with the same CD3 dimer stoichiometry. Partial reduction in the expression of the highly homologous CD3γ and CD3δ proteins would thus be expected to have a similar impact in the assembly and surface expression of both TCR isotypes. To test this hypothesis, we compared the surface TCR expression of primary αβ and γδ T cells from healthy donors carrying a single null or leaky mutation in CD3G (γ+/-) or CD3D (δ+/-, δ+/leaky) with that of normal controls.Results: Although the partial reduction in the intracellular availability of CD3γ or CD3δ proteins was comparable as a consequence of the mutations, surface TCR expression measured with anti-CD3ε antibodies was significantly more decreased in γδ than in αβ T lymphocytes in CD3γ+/- individuals, whereas CD3δ+/- and CD3δ+/leaky donors showed a similar decrease of surface TCR in both T cell lineages. Therefore, surface γδ TCR expression was more dependent on available CD3γ than surface αβ TCR expression.Conclusions: The results support the existence of differential structural constraints in the two human TCR isotypes regarding the incorporation of CD3γε and CD3δε dimers, as revealed by their discordant surface expression behaviour when confronted with reduced amounts of CD3γ, but not of the homologous CD3δ chain. A modified version of the prevailing TCR assembly model is proposed to accommodate these new data.
AB - Background: The T cell antigen receptors (TCR) of αβ and γδ T lymphocytes are believed to assemble in a similar fashion in humans. Firstly, αβ or γδ TCR chains incorporate a CD3δε dimer, then a CD3γε dimer and finally a ζζ homodimer, resulting in TCR complexes with the same CD3 dimer stoichiometry. Partial reduction in the expression of the highly homologous CD3γ and CD3δ proteins would thus be expected to have a similar impact in the assembly and surface expression of both TCR isotypes. To test this hypothesis, we compared the surface TCR expression of primary αβ and γδ T cells from healthy donors carrying a single null or leaky mutation in CD3G (γ+/-) or CD3D (δ+/-, δ+/leaky) with that of normal controls.Results: Although the partial reduction in the intracellular availability of CD3γ or CD3δ proteins was comparable as a consequence of the mutations, surface TCR expression measured with anti-CD3ε antibodies was significantly more decreased in γδ than in αβ T lymphocytes in CD3γ+/- individuals, whereas CD3δ+/- and CD3δ+/leaky donors showed a similar decrease of surface TCR in both T cell lineages. Therefore, surface γδ TCR expression was more dependent on available CD3γ than surface αβ TCR expression.Conclusions: The results support the existence of differential structural constraints in the two human TCR isotypes regarding the incorporation of CD3γε and CD3δε dimers, as revealed by their discordant surface expression behaviour when confronted with reduced amounts of CD3γ, but not of the homologous CD3δ chain. A modified version of the prevailing TCR assembly model is proposed to accommodate these new data.
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U2 - 10.1186/1471-2172-14-3
DO - 10.1186/1471-2172-14-3
M3 - Article
C2 - 23336327
AN - SCOPUS:84872382237
VL - 14
JO - BMC Immunology
JF - BMC Immunology
SN - 1471-2172
IS - 1
M1 - 3
ER -