TY - JOUR
T1 - Protein tyrosine phosphatase PTPN22 is dispensable for dendritic cell antigen processing and promotion of T-cell activation by dendritic cells
AU - Clarke, Fiona
AU - Jordan, Christine K.
AU - Gutierrez Martinez, Enrique
AU - Bibby, Jack
AU - Sanchez-Blanco, Cristina
AU - Cornish, Georgina
AU - Dai, Xuezhi
AU - Rawlings, David J.
AU - Zamoyska, Rose
AU - Guermonprez, Pierre
AU - Cope, Andrew P.
AU - Purvis, Harriet A.
PY - 2017
Y1 - 2017
N2 - The PTPN22R620W single nucleotide polymorphism increases the risk of developing multiple autoimmune diseases including type 1 diabetes, rheumatoid arthritis and lupus. PTPN22 is highly expressed in antigen presenting cells (APCs) where the expression of the murine disease associated variant orthologue (Ptpn22R619W) is reported to dysregulate pattern recognition receptor signalling in dendritic cells (DCs) and promote T-cell proliferation. Because T-cell activation is dependent on DC antigen uptake, degradation and presentation, we analysed the efficiency of these functions in splenic and GM-CSF bone marrow derived DC from wild type (WT), Ptpn22-/- or Ptpn22R619W mutant mice. Results indicated no differential ability of DCs to uptake antigen via macropinocytosis or receptor-mediated endocytosis. Antigen degradation and presentation was also equal as was WT T-cell conjugate formation and subsequent T-cell proliferation. Despite the likely presence of multiple phosphatase-regulated pathways in the antigen uptake, processing and presentation pathways that we investigated, we observed that Ptpn22 and the R619W autoimmune associated variant were dispensable. These important findings indicate that under non-inflammatory conditions there is no requirement for Ptpn22 in DC dependent antigen uptake and T-cell activation. Our findings reveal that perturbations in antigen uptake and processing, a fundamental pathway determining adaptive immune responses, are unlikely to provide a mechanism for the risk associated with the Ptpn22 autoimmune associated polymorphism.
AB - The PTPN22R620W single nucleotide polymorphism increases the risk of developing multiple autoimmune diseases including type 1 diabetes, rheumatoid arthritis and lupus. PTPN22 is highly expressed in antigen presenting cells (APCs) where the expression of the murine disease associated variant orthologue (Ptpn22R619W) is reported to dysregulate pattern recognition receptor signalling in dendritic cells (DCs) and promote T-cell proliferation. Because T-cell activation is dependent on DC antigen uptake, degradation and presentation, we analysed the efficiency of these functions in splenic and GM-CSF bone marrow derived DC from wild type (WT), Ptpn22-/- or Ptpn22R619W mutant mice. Results indicated no differential ability of DCs to uptake antigen via macropinocytosis or receptor-mediated endocytosis. Antigen degradation and presentation was also equal as was WT T-cell conjugate formation and subsequent T-cell proliferation. Despite the likely presence of multiple phosphatase-regulated pathways in the antigen uptake, processing and presentation pathways that we investigated, we observed that Ptpn22 and the R619W autoimmune associated variant were dispensable. These important findings indicate that under non-inflammatory conditions there is no requirement for Ptpn22 in DC dependent antigen uptake and T-cell activation. Our findings reveal that perturbations in antigen uptake and processing, a fundamental pathway determining adaptive immune responses, are unlikely to provide a mechanism for the risk associated with the Ptpn22 autoimmune associated polymorphism.
UR - http://www.scopus.com/inward/record.url?scp=85031821965&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0186625
DO - 10.1371/journal.pone.0186625
M3 - Article
AN - SCOPUS:85031821965
SN - 1932-6203
VL - 12
SP - 1
EP - 17
JO - PL o S One
JF - PL o S One
IS - 10
M1 - e0186625
ER -
