Hyperexpression of cyclooxygenase 2 in the lupus immune system and effect of cyclooxygenase 2 inhibitor diet therapy in a murine model of systemic lupus erythematosus.
OBJECTIVE
To investigate the role of cyclooxygenase 2 (COX-2) in the functioning of different cell types involved in the lupus autoimmune response, and to examine the therapeutic effect of COX-2 inhibitors in mice prone to spontaneously develop systemic lupus erythematosus (SLE).


METHODS
Lupus-prone (SWR x NZB)F(1) mice were fed with a diet containing different doses of the COX-2-specific inhibitor celecoxib or the nonspecific inhibitor aspirin, or a combination of both, and the effects of the therapy on autoantibody production, development of lupus nephritis, and mortality were determined. Expression of COX-2 by different cells of the lupus immune system and the effect of COX-2 inhibitors on the function of these cells in vitro and in vivo were assessed.


RESULTS
The immune cells of mice with SLE spontaneously hyperexpressed COX-2, and COX-2 inhibitors could cause cell apoptosis. Treatment with COX-2 inhibitors resulted in decreased autoantibody production and inhibition of the T cell response to the major lupus autoantigen, nucleosome, and its presentation by antigen-presenting cells. Surprisingly, a significant increase in survival occurred only in mice receiving intermittent therapy with the lowest dose of celecoxib (500 parts per million), approximating <100 mg of celecoxib/day in humans. A continuous diet, but not intermittent feeding, with the combination of celecoxib and aspirin delayed development of nephritis temporarily, but failed to prolong survival. Indeed, treatment with aspirin alone increased mortality.


CONCLUSIONS
The contributions of the major players in the pathogenic autoimmune response, namely, T cells, B cells, dendritic cells, and macrophages that are abnormally hyperactive in lupus, depend on the increased expression and activity of COX-2, similar to inflammatory cells in target organs. Intermittent pulse therapy with low doses of select COX-2 inhibitors would be of value in the treatment of lupus.
Division of Rheumatology, Northwestern University Feinberg School of Medicine, 240 East Huron Street, Chicago, IL 60611, USA.
Li
L
Zhang
Anne M
AM
Bertucci
Kimberly A
KA
Smith
Luting
L
Xu
Syamal K
SK
Datta
D000284:Administration, Oral; D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood; D017209:Apoptosis / Q000187:drug effects; D001402:B-Lymphocytes / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D000068579:Celecoxib; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D003713:Dendritic Cells / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D005921:Glomerulonephritis / Q000517:prevention & control; D007107:Immune System / Q000201:enzymology*; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008814:Mice, Inbred NZB; D011720:Pyrazoles / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology / Q000473:pathology
D000974:Antibodies, Antinuclear; D052246:Cyclooxygenase 2 Inhibitors; D011720:Pyrazoles; D013449:Sulfonamides; D051546:Cyclooxygenase 2; D000068579:Celecoxib