title: Antigen processing at the molecular level.
abstract: The recognition of antigen by helper T cells is one of the key steps in the induction of an immune response. Most helper T cells recognize a processed form of antigen; here, Paul Allen reviews the definition of antigen processing and shows that it may take at least three forms which depend upon the antigen and T cells being examined.
authors.affiliation: Department of Pathology, Washington University School of Medicine 660 S. Euclid Ave., St Louis, MO 63110, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Allen