Increased association of CD38 with lipid rafts in T cells from patients with systemic lupus erythematosus and in activated normal T cells.
In this study we have determined whether there is a relationship between CD38 expression on T cells, its distribution in different membrane microdomains, and T cell activation in SLE patients. The data show that CD38 expression is augmented in ex vivo CD3+, CD4+, CD8+, and CD25+ SLE T cells, which correlates with its increased insolubility in Brij 98 detergent, and its translocation into lipid rafts. Moreover, SLE T cells show an altered CD4:CD8 ratio, which is due to a decreased proportion of CD4+ T cells and a concomitant increase in the proportion of CD8+ T cells. These data are consistent with the increased CD38 expression and lipid raft formation, and the significant reduction in the CD4:CD8 ratio observed in mitogen-stimulated normal T cells as compared with that in ex vivo untouched normal T cells. Increased expression of CD38 in floating rafts from SLE T cells, or from activated normal T cells may modulate TCR signaling by providing or sequestering signaling molecules to the engaged TCR.
Pavón
Esther J
EJ
Departamento de Biología Celular e Inmunología, Instituto de Parasitología y Biomedicina López-Neyra, CSIC, Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento s/n, 18100 Armilla, Granada, Spain.
Muñoz
Pilar
P
Navarro
María-del-Carmen
MD
Raya-Alvarez
Enrique
E
Callejas-Rubio
José-Luis
JL
Navarro-Pelayo
Francisco
F
Ortego-Centeno
Norberto
N
Sancho
Jaime
J
Zubiaur
Mercedes
M
D051997:ADP-ribosyl Cyclase 1 / Q000032:analysis* / Q000737:chemistry; D017252:CD3 Complex / Q000032:analysis; D016516:CD4-CD8 Ratio; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D021962:Membrane Microdomains / Q000737:chemistry / Q000276:immunology*; D008934:Mitogens / Q000494:pharmacology; D010938:Plant Oils / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D012995:Solubility; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*
D017252:CD3 Complex; D008934:Mitogens; D010938:Plant Oils; D011948:Receptors, Antigen, T-Cell; D011092:Polyethylene Glycols; C033084:polyethylene glycol oleyl ether; D051997:ADP-ribosyl Cyclase 1