Premiership club Wasps have also signed five players on new, undisclosed-length contracts, for example injured New Zealand-born fly-half Jimmy Gopperth.
The 35-year-old was initially ruled out for the summer season with an anterior cruciate ligament injury in August.
But Gopperth has become predicted to make it back until the season finishes in May.
Wasps are fourth in the Premiership table after Sunday’s 24-14 loss in your home to Bath.
“With five experienced players penning new deals it sends out a quite positive message to a number of our older players,” Wasps director of rugby Dai Young said.
“The two Jimmy and Ashley are terrific athletes who give absolutely everything. Their experience throughout the plank is a must, not just in games, but in helping develop a number of the older players.
“Si, both Tommy and Ben have all been tremendous performers in front row in late seasons.”
After their fourth league defeat in five gamesthey trail third-placed Gloucester by eight things – and therefore are eight points off the base in this year’s tightly contested dining table.
But there was some consolation since the game against Bath was observed by a crowd of 31,626, the 2nd highest at the Ricoh Arena since Wasps made the stadium their home.
Their Premiership semi final against Leicester Tigers in May 2015 attracted 32,019 spectators.
Five players: 4 4 0 matches for Wasps
Gopperth has collected 771 points, chiefly with his kicking, in 78 appearances, since arriving from Newcastle at 2015, also won the Premiership Golden Boot in 2016 17.
Johnson, who plays both hooker and flanker, has scored 38 attempts in 175 matches since signing from Free State Cheetahs in 2012.
McIntyre, the longest-serving of the five players, has made 153 appearances since moving from Sale in 2011, while Taylor has played 41 times since his 20-16 move from the Sharks.