Immortals and Cloud9 join the Brazilian team SK Gaming and the European trio Gambit, fnatic and mousesports, who were previously invited to the tournament.
The Brazilian team, which took second place on the DreamHack Open Austin, is currently in search of a new fifth player after Lincoln "fnx" Lau was transferred to the bench.
The North American team was the sixth to receive an invitation to the tournament, which will take place in the summer. Cloud9 is also confirmed for the ESL Pro League 5 season finals, from May 31 to June 4, and for American minor, just four days later. Earlier this month, Cloud9 won the Subaru Invitational after defeating SK 2-0 in the final.
DreamHack Open Summer will be held from June 17 to 19 at the Elmia exhibition and conference center, in Jonkoping, with a prize fund of $ 100,000.