Immunogenicity study of recombinant human sperm-associated antigen 9 in bonnet macaque (Macaca radiata).
BACKGROUND
The human sperm-associated antigen 9 (hSPAG9) is of special interest attributing to the findings indicating that SPAG9 is an acrosomal molecule. SPAG9 is not only restricted to acrosomal compartment but also persists in equatorial segment post-acrosome reaction, which is a key location in sperm-egg interaction.


RESULTS
Immunogenicity studies in macaques were carried out with recombinant hSPAG9 (rhSPAG9) adsorbed on alum, which resulted in high titres of anti-rhSPAG9 antibodies as determined by enzyme-linked immunosorbent assay (ELISA). Immunoblotting analysis employing anti-rhSPAG9 antibodies generated in monkeys indicated that antibodies specifically reacted with native SPAG9 from macaque and human sperm and rhSPAG9 protein. Furthermore, indirect immunofluorescence experiments demonstrated SPAG9 localization in the acrosomal compartment of macaque and human sperm. In addition, monkey antibodies against rhSPAG9 significantly inhibited the human spermatozoa adherence or penetration in zona-free hamster oocytes.


CONCLUSIONS
These results demonstrate that rhSPAG9 adsorbed on alum is highly immunogenic in subhuman primate model and therefore represents a suitable sperm-based vaccine immunogen for fertility trials in macaque.
Rana
Ritu
R
Genes and Proteins Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
Jagadish
Nirmala
N
Garg
Manoj
M
Mishra
Deepshikha
D
Dahiya
Neetu
N
Chaurasiya
Dipak
D
Suri
Anil
A
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000276:immunology*; D000818:Animals; D003001:Cloning, Molecular; D006801:Humans; D007114:Immunization; D015151:Immunoblotting; D008255:Macaca radiata / Q000276:immunology*; D008297:Male; D011994:Recombinant Proteins / Q000276:immunology; D013094:Spermatozoa / Q000276:immunology; D014612:Vaccines
D048868:Adaptor Proteins, Signal Transducing; D011994:Recombinant Proteins; C111047:SPAG9 protein, human; D014612:Vaccines