The role of acrosin and antibodies to acrosin in gamete interactions

P 3 THE ROLE OF INTERACTIONS

AND

ACROSIN

39

ANTIBODIES

R O M M Y VON BERNHARDI, LUZ P. BLANCO, BECKER, C L A U D I O BARROS, P I L A R VIGIL,

TO

ACROSIN

L I S E T T E LEYTON, A.E. DE IOANNES.

IN G A M E T E

MARIA

INES

F a c u l t a d de C i e n c i a s B i o l 6 g i c a s , P. U n i v e r s i d a d C a t 6 1 i c a de Chile. A c r o s i n is a serine p r o t e a s e l o c a l i z e d in the m a m m a l i a n sperm acrosome. D u e to its p r o t e o l y t i c activity, it would s p e r m an important role in the reproductive process, aiding the p e n e t r a t i o n and b i n d i n g of the s p e r m a t o z o a in the zona pellucida. Acr-C2E5 is a monoclonal antibody directed to bovine a c r o s i n that c r o s s - r e a c t w i t h the enzyme from human, mice and hamster. It i n h i b i t s the d i s s o l u t i o n of the hamster zona p e l l u c i d a by p u r i f i e d human a c r o s i n in a dose d e p e n d e n t manner. Furthermore, in a a s s a y of gamete a t t a c h m e n t and p e n e t r a t i o n of human zona p e l l u c i d a by h u m a n spermatozoa, w h e n A c r - C 2 E 5 is added at the i n s e m i n a t i o n stage, the n u m b e r of s p er m cells b o u n d to the zona decreases, as c o m p a r e d w i t h controls. Similar effects w i t h the mou s e h a m s t e r in v i t r o f e r t i l i z a t i o n system have been shown by u si n g s c a n n i n g e l e c t r o n m i c r o s c o p y . We have seen that few sperms can p e n e t r a t e the h a m s t e r zona in the presence of monoclonal a n t i b o d i e s to acrosin. Our results s u g g e s t that a c r o s i n is i n v o l v e d in the a t t a c h m e n t of the sperms b e c a u s e it should exert some s e l e c t i v e d e g r a d a t i o n over the zona g l y c o p r o t e i n s in order that ZP2 be better exposed on the zona surface allowing a tight i n t e r a c t i o n with sperm r e c e p t o r s p r e s e n t on inner a c r o s o m a l membrane. S u p p o r t e d by F O N D E C Y T # 216-88 and CONRAD #CSA-89-040. Acrosin,

antibodies,

gamete.

P4 IMPACT

OF

DEGLYCOSYLATED

RABBITS FOLLOWING

ZONA

PELLUCIDA

ANTIGENS

ON

FERTILITY

IN

ACTIVE IMMUNIZATION

P. Bhatnagar and S. Sehgal, Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh - 160012, India

The immunogenecity of d e g l y c o s y l a t e d porcine zona p e l l u c i d a antigens, and t h e i r potential r o l e in i n t e r c e p t i n g f e r t i l i t y following a c t i v e immunization in r a b b i t s h a v e been e v a l u a t e d . Native zona p e l l u c i d a g l y c o p r o t e i n s were d e g l y c o s y l a t e d with tr i f lu o r o m e t h a n e s u l f o n ic acid by t h e standard procedure. Antisera to d e g l y c o s y l a t e d zona p e l l u c i d a (DGHSPZ) were r a i s e d in r a b b i t s and c i r c u l a t i n g anti-DGHSPZ a n t i b o d i e s were a s s a y e d by immunoelectrophoresis and enzyme-linked immunosorbent a s s a y s . Significant antibody l e v e l s were d e t e c t a b l e in a l l t h e animals immunized with DGHSPZ, t h e r e b y , indicating t h a t d e g l y c o s y l a t e d p r o t e i n s a r e also good immunogens. The antibody response was, h o w e v e r , much h i g h e r against t h e n a t i v e zona p e l l u c i d a , suggesting that both carbohydrate immunological properties by f e r t i l i t y studies.

Zona p e l l u c i d a ,

and protein components are responsible for the of zona pellucida. The results were corroborated

d e g l y c o s y l a t i o n , immunogenecity.