England captain Packer to win 100th Test cap in Women's Six Nations opener
The 34-year-old Saracens flanker, who made her senior international debut in 2008, is the seventh woman to reach the landmark for England.
"Reaching 100 caps for your country is an awesome achievement," said England coach John Mitchell after naming his side on Thursday for the match in Parma.
“Talking to Marlie about her journey, she has had to overcome adversity since her Test debut in 2008.
"What has been evident since I first met her is that her determination to succeed has been ingrained in her over the past 16 years, helping her achieve what she has in the game."
Packer, who missed the entire 2020 Six Nations with a serious ankle injury, is one of only five players who have retained their starting places following England's 33-12 win against New Zealand in November, which meant the Red Roses clinched the inaugural WXV1 title.
The tournament was designed by World Rugby to improve standards in the women's game between World Cups, which take place every four years.
England have won the Women's Six Nations for five successive years, with only a change in format in 2021 preventing them from winning a Grand Slam on each occasion.
They also won 30 Tests in a row from 2019 until 2022 against all opponents but that record streak ended with defeat by New Zealand in the World Cup final.
Mitchell, a native New Zealander and former head coach of the men's All Blacks, aims to help them go one better when England stage next year's World Cup.
"We are focused on improving our performance," he said. "We want to get quicker at our game, we want to create more pressure on the opposition and we want to present attacking opportunities.
"Italy is our first opportunity to put into practice what we are aiming to achieve."