Molecular genetics of human immune responsiveness to Lolium perenne (rye) allergen, Lol p III

Int Arch Allergy Appl Immunol. 1989;88(1-2):164-9. doi: 10.1159/000234774.


Lol p II and III are each about 11-kD protein allergens from the pollen of Lolium perenne (rye grass). We have found that human immune responses (IgE and IgG antibodies) to both proteins are significantly associated with HLA-DR3. In addition, the two proteins are cross-reactive with the antibodies in many human sera (about 84% human sera showed the cross-reactivity). We have determined greater than 90% of the amino acid sequences of the two proteins and found that they are at least 54% homologous. Berzofsky found that 75% of the 23 known T cell sites in various proteins had an amphipathic structure. Our analysis by the same method showed that both Lol p II and III have a major region of amphipathicity (at residues 61-67, Lol p III numbering) which might contain sites for binding to an Ia molecule and a T cell receptor. This region is identical between Lol p II and III, except for an Arg-Lys substitution, and could account, in part, for the DR3 association with responsiveness to both molecules. An interesting difference between the two proteins is that immune response to Lol p III is associated with DR5 (in addition to DR3), whereas no DR5 association is found in the case of Lol p II. One possibility is that Lol p III has an additional site which binds to the DR5 Ia molecule. Lol p III indeed has a second highly amphiphathic peptide, 24-30 (Lol p III 24 R P G D T L A 30), which is different and not amphipathic in Lol p II.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Allergens*
  • Edible Grain*
  • Genes, MHC Class II*
  • HLA-DQ Antigens / genetics
  • HLA-DR Antigens / genetics*
  • Humans
  • Immunoglobulin E / immunology
  • Pollen / immunology
  • Secale*
  • Sex Factors


  • Allergens
  • HLA-DQ Antigens
  • HLA-DR Antigens
  • Immunoglobulin E