hybridoma supernatant, what's in it other than MAB ?

[khm]

Hi,
I had a strange effect of rat hybridoma supernatant that is not an effect of the MAB itself ( 83A25).

Some component in the rat hybridoma supernatant influenced gamma retrovirus infection, either with the cellular Pit receptor or with the envelope proteins, when added to human TE cells and gamma retrovirus.

Does anybody have an idea what this active cellular component could be ??

I'm doing my early graduate work in the lab.
Thanks