Knocking out of CD38 accelerates development of a lupus-like disease in lpr mice.

OBJECTIVES: CD38 participates in lymphocyte ontogeny and function and may be involved in autoimmunity. Absence of CD38 accelerates development of non-obese diabetic (NOD) mice diabetes and anti-CD38 antibodies are good markers of human disease. Little is known regarding systemic autoimmunity. Active SLE patients have higher numbers of CD38(+) T and B cells. CD38 is a candidate gene for the murine Lmb2 lupus locus. We aimed to investigate whether CD38 was involved in lupus development.
METHODS: We developed Cd38(-/-)-Fas(lpr)/Fas(lpr) mice and monitored them for development of a lupus-like disease through measurement of protein excretion in urine, histological assessment of the kidneys, quantification of circulating immunoglobulins and autoantibodies. We have also immunophenotyped 2- and 6-month old Cd38(-/-)-Fas(lpr)/Fas(lpr) mice.
RESULTS: We found that absence of CD38 accelerated disease development: female Cd38(-/-)-Fas(lpr)/Fas(lpr) mice presented severe proteinuria, GN, deposition of ICs in the renal medulla and increased amounts of circulating immunoglobulin G (IgG), although anti-dsDNA autoantibodies and RF were not significantly increased at disease onset. We have found that Cd38(-/-)-Fas(lpr)/Fas(lpr) male mice, similarly to other murine models of lupus, were able to control disease. Absence of CD38 in lpr mice altered differentiation of T cells and dendritic cells (DC).
CONCLUSION: Although the role of CD38 in tolerance is still to be elucidated, we provide evidence that it may play an active role in the control of a murine lupus-like disease.