IgA

Tomasi and coworkers demonstrated that IgA present in saliva and colostrum is produced locally and secreted as a dimer or trimer by (Tomasi TB et al., J Exp Med 121:101-124, 1965) and Newcomb and coworkers demonstrated the existence of the secretory piece (Newcomb RW et al., J immunol 101:905-913, 1968).