Relationship between beta cell mass of NOD donors and diabetes development of NOD-scid recipients in adoptive transfer system.
BACKGROUND
There is controversy about the way the beta cell mass is reduced in type 1 diabetes. One view is that a gradual fall in beta cell mass begins soon after the onset of insulitis. Another view is that a sudden wave of beta cell destruction occurs just before the onset of diabetes. To clarify how the beta cell mass is reduced, we performed adoptive transfer experiments and examined the relationship between the pancreatic status of NOD donors and the time taken to transfer diabetes into NOD-scid recipients.


METHODS
We killed 18-week-old female NOD mice (n = 20), removed their spleen, and transferred splenocytes into 5-week-old female NOD-scid mice (n = 60). The relationship between the pancreatic status of donors and the time taken to transfer diabetes into recipients was assessed. As pancreatic status, we measured insulin content and severity of insulitis.


RESULTS
There was no linear correlation between the pancreatic status of donors and the time taken to transfer diabetes into recipients. NOD donors who needed 7 or more weeks to transfer diabetes in NOD-scid recipients had similar levels of insulin content or severity of insulitis as those of NOD donors who could not transfer diabetes. On the other hand, NOD donors who needed 6 or less weeks to transfer diabetes in recipients had similar levels of insulin content or severity of insulitis as those of diabetic NOD mice.


CONCLUSIONS
According to our observations, beta cell mass seems to be preserved until just before the onset of diabetes and decreased dramatically within a few weeks.
Yamada
Satoru
S
Department of Internal Medicine, Kitasato Institute Hospital, Tokyo, Japan.
Shimada
Akira
A
Kodama
Keiichi
K
Morimoto
Jiro
J
Suzuki
Ryuji
R
Oikawa
Yoichi
Y
Irie
Junichiro
J
Saruta
Takao
T
D019264:Adoptive Transfer; D000818:Animals; D003922:Diabetes Mellitus, Type 1 / Q000473:pathology* / Q000628:therapy; D007515:Islets of Langerhans / Q000473:pathology*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID