WS22-6
*5
P O S S I B L E M E C H A N I S M OF P R E V E N T I V E E F F E C T OF BCG ON D I A B E T E S M E L L I T U S IN NOD MICE H. YAGI and M. H A R A D A SHIONOGI R E S E A R C H L A B O R A T O R I E S , SHIONOGI & CO., LTD., OSAKA, JAPAN We have e l u c i d a t e d that a single i n t r a v e n o u s i n j e c t i o n of BCG prevents the p a t h o g e n e s i s of NOD mice. D e v e l o p m e n t of o v e r t d i a b e t e s is also suppressed by t r a n s f e r of spleen cells from B C G - v a c c i n a t e d mice. Therefore, it is evident that some type of s u p p r e s s o r cells is g e n e r a t e d by BCG-treatment. In the p r e s e n t study, we a n a l y z e d the s u p p r e s s o r cells by means of in vitro i m m u n o l o g i c a l assays. (I) F~ow c y t o m e t r i c a n a l y s i s of the spleen cells r e v e a l e d that Mac-i T and Mac-2 cells i n c r e a s e d in B C G - t r e a t e d mice. (2) Spleen cells of BCGv a c c i n a t e d mice were very low in r e s p o n s i v e n e s s to various m i t o g e n s such as Con A, PHA, PWM, LPS and allo antigens. (3) W h e n p l a s t i c - a d h e r e n t cells were removed, the spleen cells of B C G - v a c c i ~ a t e d mice r e s p o n d e d to the mitogens. (4) A d d i t i o n of F A C S - s o r t e d Mac-I cells from B C G - t r e a t e d mice s u p p r e s s e d the Con A r e s p o n s e of m a c r o p h a g e - d e p l e t e c spllen cells. These results i n d i c a t e that s u p p r e s s o r m a c r o p h a g e s are g e n e r a t e d by BCGt r e a t m e n t and suggest that these cells p r e v e n t the a u t o i m m u n e p a t h o g e n e s i s leading to diabetes.
WS22-7
"6
PRODUCTION OF PROSTAGLANDIN E 2 (PGE 2) ~ BY MICE INFECTED WITH MYCOBACTERIUM AVIUM COMPLEX (MAC), Pattisapu R.3. Gangadharam, Robert Taylor~ and Carl C.K. Edwards III, Mycobacteriology R e s e a r c h Laboratories, National 3ewish C e n t e r for Immunology and R e s p i r a t o r y Medicine 9 Denver, CO 80206. Previous studies from our laboratory have shown that infection by M. a v i u m - i n t r a c e l l u l a r e complex (MAC) of low virulence in S/W mice caused an increase in PGE2 release and reduction in both./, i n t e r f e r o n and interleukin-2 release by T lymphocytes. These studies are e x t e n d e d to assess the ability of high and low virulent strains ol MAC in inducing the release of superoxide anion (02) and PGE 2 from S/YI' mice and c o m p a r e d with beige mice which have been shown by us to be most susceptible to MAC infection. Both high virulent strain 101 and low virulent strain 1/403 of MAC caused gradual increase in PGE 2 release with the progression of MAC infection. There was no significant d i f f e r e n c e b e t w e e n the two MAC strains or the two strains of mice with r e s p e c t to PGE 2 r e l e a s e a l t e r MAC infection. The results of the present study thus suggest that the increased susceptibility of the beige mouse to MAC infection is not due to unusually high production of PGE 2. In confirmation with our earlier findings, low virulent MAC strain (1/~03) induced more 02 r e l e a s e than the high virulent strain (101) in both strains of mice. This r e s e a r c h is supported by an NIH grant AI 21897.
WS22-8
*7
S A N D I M M U N DOES NOT INHIBIT CLASS II MHC R E S T R I C T E D P R E S E N T A T I O N OF S O L U B L E ANTIGENS. S e r g i o A b r i g n a n i and S a l v a t o r e C a m m i s u l i P r e c l i n i c a l R e s e a r c h Department, Sandoz Ltd, Basle, S w i t z e r l a n d . It has been r e p o r t e d that S a n d i m m u n (Ciclosporin A, Sim) inhibits a n t i g e n p r e s e n t a t i o n to T cells. However, these studies m i g h t be b i a s e d by the fact that drug carried over by the p r e t r e a t e d antigen p r e s e n t i n g cells (APCs) could d i r e c t l y i n h i b i t a n t i g e n induced T cell a c t i v a t i o n in spite of normal a n t i g e n p r e s e n t a t i o n . To b y p a s s this p r o b l e m we used CD4+, class II FHC r e s t r i c t e d antigen s p e c i f i c T cells, able both to p r o l i f e r a t e in r e s p o n s e to, and to kill a n t i g e n p u l s e d EBV t r a n s f o r m e d B cells (EBV-B) acting as APCs. It should be n o t e d that this latter a c t i v i t y is not inhibited by Sim. We found that EBV-B, p u l s e d with a n t i g e n e i t h e r in the p r e s e n c e or the absence of Sim, w e r e e q u a l l y s u s c e p t i b l e to k i l l i n g by class II r e s t r i c t e d T cells, whereas EBV-B, p u l s e d w i t h a n t i g e n in the p r e s e n c e of Sim, p a r t i a l l y i n h i b i t e d T cell p r o l i f e r a t i o n . This i n h i b i t o r y e f f e c t was a b r o g a t e d if the pulsed APCs w e r e fixed with g l u t a r a l d e h y d e b e f o r e c o c u l t u r e with the a n t i g e n specific T cells. This finding s u g g e s t s that the i n h i b i t i o n seen at the T cell p r o l i f e r a t i o n level is due to a drug carry over by the u n f i x e d APCs. On the w h o l e our results d e m o n s t r a t e that Sim does not affect uptake, p r o c e s s i n g and p r e s e n t a t i o n of soluble a n t i g e n s by E B V - B cells.
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