Jdb file will update only the antivirus & antispyware definitions in the SEPM. The default configuration of SEPM meets your needs.
Because by default:
1. Liveupdate button is disabled in the SEP client interface
2. SEP client is supposed to take the definitions only from SEPM.
If you have installed the SEP clients with only AV/AS then, they should be able to take the definitions from SEPM.
Make sure that the clients are communicating with the SEPM.
Cheers,
Aniket