Increased numbers of Th2-like CD4+ T cells in target organs and in the allergen-specific repertoire of allergic patients. Possible role of IL-4 produced by non-T cells.
Phytohemagglutinin (PHA)-induced human T cell clones (TCC) derived from conjunctival flogistic tissues of 3 patients with vernal conjunctivitis produced unusually high amounts of interleukin-4 (IL-4) and no, or limited amounts of, gamma-interferon (IFN-gamma). Allergen (Dermatophagoides pteronyssinus or Lolium perenne group I)-specific TCC derived from peripheral blood of two atopic donors produced significantly higher amounts of IL-4 and significantly lower amounts of IFN-gamma than TCC specific for bacterial antigens (tetanus toxoid and PPD) contemporarily established from the same donors. These data provide evidence for a compartimentalization of Th2-like helper T cells in target organs and in the allergen-specific T cell repertoire of allergic patients. Non-B, non-T bone marrow cells could produce IL-4, but not IL-2 or IFN-gamma, in response to cross-linkage of Fc epsilon type I receptors. These cells may further contribute to the maintenance and amplification of allergic inflammation.
Romagnani
S
S
Division of Clinical Immunology and Allergology, University of Florence, Italy.
Maggi
E
E
Parronchi
P
P
Macchia
D
D
Piccinni
M P
MP
Ricci
M
M
D000485:Allergens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D002451:Cell Compartmentation; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D015847:Interleukin-4 / Q000502:physiology*; D007958:Leukocyte Count; D008407:Mast Cells / Q000502:physiology; D013234:Stem Cells / Q000502:physiology; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology*
D000485:Allergens; D015847:Interleukin-4