Groovy to Linux variable

Hello all,
I'm struggling to convert a groovy variable to use in a bash command. Any help would be great. Can anyone see what I am doing wrong?

def teamname = "${loweritam}"
sh '''
appteam="""$teamname-REL"""
team=ap123456
echo $appteam $team
'''
Output:
+ appteam=-REL
+ team=ap123456
+ echo -REL ap123456
-REL ap123456

appteam should look like - 12345tr-REL
I've tried using single quotes like so: appteam='''+teamname+'-REL''''

but that does not work for me either.

thanks,
Fluke