Can I get a body fat transfer from someone else? If not, why not?

No it is not possible to take anyone else's tissue and fat cells but your own.  Look at these as living fat cells not fat.  Living fat cells from someone else will be recognized as foreign by your body and will be eliminated by your immune response.  

I wish it was!  Your own fat is specific to you, its like donating blood or an organ.  If you get fat from another person you can transmit infection and it wont last, because it only grafts to your own body.  I suggest seeing a physician who specializes in fat transfer and uses PRP to enhance the results.  Best, Dr. Emer.

Unfortunately you cannot transplant your fat to another individual. Transplantation of tissue is complex and requires a number of closely monitored medications.

Unfortunately, all cells in our bodies are coded with our own special DNA and cell types and just as a kidney or heart transplant can be rejected if it's not a match, so can fat.  So unfortunately, no you cannot use someone else's fat for fat transfer and vice versa.  Hopefully we'll find a solution to this in the future. 

Unfortunately you can NOT get fat from another person.  Fat is filled with living cells and it is a transplant if taken from someone else and your body will reject them.