Rapamycin is used clinically as an immunosuppressant and prevents the proliferation of T cells and B cells.  Paradoxically, even though rapamycin is a federally approved immunosuppressant , its inhibition of mTORC1 results in better quantity and quality of functional memory T cells . mTORC1 inhibition with rapamycin improves the ability of naïve T cells to become precursor memory T cells during the expansion phase of T cell development .  This inhibition also allows for an increase in quality of these memory T cells that become mature T cells during the contraction phase of their development.  mTORC1 inhibition with rapamycin has also been linked to a dramatic increase of B cells in old mice, enhancing their immune systems .  This paradox of rapamycin inhibiting the immune system response has been linked to several reasons, including its interaction with regulatory T cells . 
Hmmmm interesting. Funny you mention it because I was taking gaba not too long ago and it was in a mixture with some other stuff. Anyways, I think it was causing me to wake up kind of uncoordinated and feeling just kind of weird. Dissociative I guess you could say, which makes sense because it’s related to the NMDA receptors somehow I think. It supposedly “can’t” cross the blood brain barrier, at least this is repeated despite the fact that it can and does, it’s just an unreliable mechanism in which it does. Low levels of gaba were insinuated to absorb more in the brain also. I didn’t have this issue as if I took the full 750 mg I felt very strange consistently and none of the other supplements in the mixture would seem to do this.
Resveratrol is a wine phenolic that is known to interact with sirtuin proteins (mostly SIRT1) which is similar to leucine; the metabolites of KIC and HMB at are able to induce SIRT1 to 30-100% of baseline which is a comparable potency to 2-10μM resveratrol  although the combination of leucine () or HMB (μM) and resveratrol (200nM) is able to synergistically induce SIRT1 and SIRT3 activity in both adipocytes and skeletal muscle cells.  KIC appears to be a more potent stimulator than HMB,  and synergism appears to be greater with leucine than with HMB (possibly indicative of KIC metabolism).