Winger Alesana, 26, ended the season in top form with Leicester Tigers, playing in three finals for the club and picking up the Members' Player of the Season award before joining the Samoa squad for the Pacific Nations Cup where he scored a try in the win over Tonga.
Powerhouse forward Henry, 30, enjoyed four seasons at Welford Road before this summer, while 21-year-old Anitelea, a centre, has sealed a move to Guinness Premiership newcomers Leeds Carnegie after playing on loan there from Tigers last season.
Samoa coach Michael Jones has also included veteran Brian Lima who will appear at a record fifth World Cup.
Lima, nicknamed 'The Chiropractor' for his tackling power, was with Bristol Rugby in the Premiership last season.
A centre or wing, Lima was the youngest player at the 1991 World Cup at just 19, and has featured in each of the subsequent tournaments.
Samoa have scheduled warm-up games against Harlequins, Northampton Saints and Sale Sharks before their World Cup-opener against South Africa on September 9. They also face England and Tonga in the pool stages.
Samoa squad
Forwards
Census Johnston (Saracens)
Justin Va'a (Glasgow Warriors)
Kasiano Lealamajua (Dax)
Donald Kerslake (Vaiala)
Mahonri Schwalger (Hurricanes)
Muliufi Salanoa (Scopa)
Silao Vaisolasefo (Alhambra)
Filipo Levi (Ricoh)
Kane Thompson (Wests)
Iosefa Fekori (Auckland)
Daniel Leo (London Wasps)
Henry Tuilagi
Siu Lafaialii (Yokogawa)
Semo Setiti (Docomo)
Ulia Ulia (Marist)
Justin Purdie (Wellington)
Backs
Steven So'oialo (Harlequins)
Junior Poluleuligaga (North Harbour)
Loki Crichton (Worcester Warriors)
Lolo Lui (Moataa)
Seilala Mapusua (London Irish)
Eliota Sapolu Fuimaono (Bath Rugby)
Jerry Meafou (Scopa)
Elvis Sevealii (Sale Sharks)
Anitelea Tuilagi (Leeds Carnegie)
Brian Lima (Bristol Rugby)
David Lemi (Bristol Rugby)
Lome Faatau (Glasgow Warriors)
Alesana Tuilaga (Leicester Tigers)
Gavin Williams (Ponsonby)
