Quick Answer .. 2 Ways:
Assumption: the JMS Message is on a Queue.
1) Correct (but Messy way) : Deploy an MDB that reads the queue or whatever and triggers the BPD via REST
2) Easy Peasy way: use integration.jar to read the queue (loop with a timer, my favourite is 5 secs for low load and 1 second for high load. For extreme load, read messages and insert into list (batch read) ) and create a caller BPD. Then from this "caller" BPD use UCA to start the main BPD.