Role of endogenous annexin-A1 in the regulation of thymocyte positive and negative selection

TY - JOUR

T1 - Role of endogenous annexin-A1 in the regulation of thymocyte positive and negative selection

AU - Paschalidis, Nikolaos

AU - Huggins, Anthony

AU - Rowbotham, Nicola J

AU - Furmanski, Anna L

AU - Crompton, Tessa

AU - Flower, Roderick J

AU - Perretti, Mauro

AU - D'Acquisto, Fulvio

PY - 2010/2/15

Y1 - 2010/2/15

N2 - We have recently shown that endogenous Annexin-A1 (AnxA1) plays a homeostatic regulatory role in mature T cells by modulating the strength of TCR signaling. In this study we investigated the role of endogenous AnxA1 in thymocyte maturation. Analysis of AnxA1(-/-) thymocyte populations at the immature CD4(-)CD8(-) double negative (DN) stage showed a proportional decrease in the DN1 and an increase in the DN3 subsets compared to control littermates. There were no significant differences in thymocyte numbers or proportions of CD4(+) and CD8(+) single positive (SP) populations between Anx1(-/-) and AnxA1(+/+) mice. However, when we crossed AnxA1(-/-) mice onto HY-TCR transgenic mice, we observed an increase in CD4(+)CD8(+) double positive (DP) and CD4 SP cells in male AnxA1(-/-)/HY-TCR compared to AnxA1(+/+)/HY-TCR. Conversely, female AnxA1(-/-)/HY-TCR mice showed an increase in DP and a decrease in CD8 (SP) cells compared to female AnxA1(+/+)/HY-TCR. Biochemical analysis of the signaling pathways responsible for these effects showed a decrease in anti-CD3-induced Erk phosphorylation and NFkappaB activation in AnxA1(-/-) thymocytes compared to control littermates. Together these findings demonstrate a role for endogenous AnxA1 in regulating both positive and negative selection of the TCR repertoire. These results suggest that targeting AnxA1 expression or function in T cells could represent a useful approach for the development of novel therapies for the treatment of autoimmune diseases.

AB - We have recently shown that endogenous Annexin-A1 (AnxA1) plays a homeostatic regulatory role in mature T cells by modulating the strength of TCR signaling. In this study we investigated the role of endogenous AnxA1 in thymocyte maturation. Analysis of AnxA1(-/-) thymocyte populations at the immature CD4(-)CD8(-) double negative (DN) stage showed a proportional decrease in the DN1 and an increase in the DN3 subsets compared to control littermates. There were no significant differences in thymocyte numbers or proportions of CD4(+) and CD8(+) single positive (SP) populations between Anx1(-/-) and AnxA1(+/+) mice. However, when we crossed AnxA1(-/-) mice onto HY-TCR transgenic mice, we observed an increase in CD4(+)CD8(+) double positive (DP) and CD4 SP cells in male AnxA1(-/-)/HY-TCR compared to AnxA1(+/+)/HY-TCR. Conversely, female AnxA1(-/-)/HY-TCR mice showed an increase in DP and a decrease in CD8 (SP) cells compared to female AnxA1(+/+)/HY-TCR. Biochemical analysis of the signaling pathways responsible for these effects showed a decrease in anti-CD3-induced Erk phosphorylation and NFkappaB activation in AnxA1(-/-) thymocytes compared to control littermates. Together these findings demonstrate a role for endogenous AnxA1 in regulating both positive and negative selection of the TCR repertoire. These results suggest that targeting AnxA1 expression or function in T cells could represent a useful approach for the development of novel therapies for the treatment of autoimmune diseases.

KW - Animals

KW - Annexin A1

KW - CD4 Antigens

KW - CD8 Antigens

KW - Extracellular Signal-Regulated MAP Kinases

KW - Female

KW - Flow Cytometry

KW - Genotype

KW - Male

KW - Mice

KW - Mice, Inbred C57BL

KW - Mice, Transgenic

KW - NF-kappa B

KW - Phosphorylation

KW - Receptors, Antigen, T-Cell

KW - T-Lymphocytes

KW - Thymus Gland

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

M3 - Article

C2 - 20139728

SN - 1538-4101

VL - 9

SP - 785

EP - 794

JO - Cell cycle (Georgetown, Tex.)

JF - Cell cycle (Georgetown, Tex.)

IS - 4

ER -