Jenkins comes into the front-row and will win his 102nd Wales cap a the Aviva Stadium alongside Richard Hibbard and Adam Jones (both Ospreys).
In the second-row Coombs, who made his debut against Ireland twelve months ago replaces Luke Charteris who is ruled out with a hamstring injury and he will partner Alun Wyn Jones (Ospreys) who led Wales to their opening day victory.
Warburton, who featured off the bench against the Azzurri, starts at openside flanker alongside Dan Lydiate (Racing Metro) and Taulupe Faletau (Newport Gwent Dragons). Since making his Six Nations debut at the Aviva Stadium in 2012 Faletau has started every match in the competition for Wales.
The backline remains unchanged for the trip across the Irish sea.
Full-back Leigh Halfpenny will win his 50th cap aged just 25. He again lines -up in a back three alongside Alex Cuthbert (Cardiff Blues) and George North (Northampton Saints) for a 12th straight time in the Six Nations.
Try scorer at the Millennium Stadium last Saturday, Scott Williams (Scarlets), and Racing Metro's Jamie Roberts continue their partnership in the midfield, with Rhys Priestland (Scarlets) and Mike Phillips (Racing Metro) featuring at half-back.
"It's great to bring Sam and Gethin back into the side and it's a good opportunity for Andrew Coombs to start as well," said Gatland.
"Last weekend was a good hit out for a lot of reasons, but we still have things to work on and we know how important this game is.
"We haven't lost an away match in the Six Nations since 2011 and we have to have the belief and confidence that we can do it again this weekend.
"It's going to be tough, both sides won their opening game, we will have to be physical and take it to them.
"We feel in most tournaments we get stronger as it goes on and that will need to be the case this weekend."
On the bench Paul James (Bath Rugby) will win his 50th cap if he takes to the field and he is joined amongst the replacement s by Scarlets front-row duo Ken Owens and Rhodri Jones. Uncapped Scarlets second-row Jake Ball features in a match-day squad for the first time and is named alongside Justin Tipuric (Ospreys), Rhys Webb (Ospreys), James Hook (Perpignan) and Liam Williams (Scarlets).
WALES SQUAD TO PLAY IRELAND:
Leigh Halfpenny (Cardiff Blues), Alex Cuthbert (Cardiff Blues), Scott Williams (Scarlets), Jamie Roberts (Racing Metro), George North (Northampton Saints), Rhys Priestland (Scarlets), Mike Phillips (Racing Metro), Gethin Jenkins (Cardiff Blues), Richard Hibbard (Ospreys), Adam Jones (Ospreys), Andrew Coombs (Newport Gwent Dragons), Alun Wyn Jones (Ospreys), Dan Lydiate (Racing Metro), Sam Warburton (CAPT - Cardiff Blues), Taulupe Faletau (Newport Gwent Dragons).
Replacements: Ken Owens (Scarlets), Paul James (Bath Rugby), Rhodri Jones (Scarlets), Jake Ball (Scarlets), Justin Tipuric (Ospreys), Rhys Webb (Ospreys), James Hook (Perpignan), Liam Williams (Scarlets).