The role of the LAT-PLC-gamma1 interaction in T regulatory cell function.
The interaction between the linker for activation of T cells (LAT) with PLC-gamma1 is important for TCR-mediated Ca(2+) signaling and MAPK activation. Knock-in mice harboring a mutation at the PLC-gamma1 binding site (Y136) of LAT develop a severe lymphoproliferative syndrome. These mice have defective thymic development and selection and lack natural regulatory T cells, implicating a breakdown of both central and peripheral tolerance. To bypass this developmental defect, we developed a conditional knock-in line in which only LATY136F is expressed in mature T cells after deletion of the wild type LAT allele. Analysis of LATY136F T cells indicated that the interaction between LAT and PLC-gamma1 plays an important role in TCR-mediated signaling, proliferation, and IL-2 production. Furthermore, the deletion of LAT induced development of the lymphoproliferative syndrome in these mice. Although Foxp3(+) natural Treg cells were present in these mice after deletion, they were unable to suppress the proliferation of conventional T cells. Our data indicate that the binding of LAT to PLC-gamma1 is essential for the suppressive function of CD4(+)CD25(+) regulatory T cells.
Chuck
Mariana I
MI
Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
Zhu
Minghua
M
Shen
Shudan
S
Zhang
Weiguo
W
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D005260:Female; D005434:Flow Cytometry; D017353:Gene Deletion; D055879:Gene Knock-In Techniques; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D008232:Lymphoproliferative Disorders / Q000235:genetics / Q000276:immunology / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D051966:Phospholipase C gamma / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D011485:Protein Binding; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology / Q000378:metabolism / Q000473:pathology
D048868:Adaptor Proteins, Signal Transducing; D007376:Interleukin-2; C491734:Lat protein, mouse; D008565:Membrane Proteins; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; D051966:Phospholipase C gamma