The proapoptotic and antimitogenic protein p66SHC acts as a negative regulator of lymphocyte activation and autoimmunity.
The ShcA locus encodes 3 protein isoforms that differ in tissue specificity, subcellular localization, and function. Among these, p66Shc inhibits TCR coupling to the Ras/MAPK pathway and primes T cells to undergo apoptotic death. We have investigated the outcome of p66Shc deficiency on lymphocyte development and homeostasis. We show that p66Shc(-/-) mice develop an age-related lupus-like autoimmune disease characterized by spontaneous peripheral T- and B-cell activation and proliferation, autoantibody production, and immune complex deposition in kidney and skin, resulting in autoimmune glomerulonephritis and alopecia. p66Shc(-/-) lymphocytes display enhanced proliferation in response to antigen receptor engagement in vitro and more robust immune responses both to vaccination and to allergen sensitization in vivo. The data identify p66Shc as a negative regulator of lymphocyte activation and show that loss of this protein results in breaking of immunologic tolerance and development of systemic autoimmunity.
Finetti
Francesca
F
Department of Evolutionary Biology, University of Siena, Siena, Italy.
Pellegrini
Michela
M
Ulivieri
Cristina
C
Savino
Maria Teresa
MT
Paccagnini
Eugenio
E
Ginanneschi
Chiara
C
Lanfrancone
Luisa
L
Pelicci
Pier Giuseppe
PG
Baldari
Cosima T
CT
D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000502:physiology*; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000502:physiology*; D015551:Autoimmunity; D006706:Homeostasis; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000166:cytology; D051379:Mice; D018345:Mice, Knockout; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1