title: Expansion of CD3+CD4-CD8- T cell population expressing high levels of IL-5 in Omenn's syndrome.
abstract: Omenn's syndrome is a fatal, autosomal-recessive combined immune deficiency characterized by several erythematous exfoliative eruptions, lymphadenopathy, hepatosplenomegaly, and elevated eosinophil count. In some of these patients an expansion of CD3+CD4-CD8- double negative (DN) T cell population was observed. We show here that the DN population represents a clonal expansion of T cells which preferentially use V beta 14 in their T cell receptor complex. Using polymerase chain reaction, we show that patient's DN cells express spontaneously high levels of IL-5, thus possibly explaining the abundance of eosinophils in this disorder. The increase of IgE observed in patients with Omenn's syndrome is unlikely to be related to IL-4 production, as IL-4 levels in patient samples were low. However, patient's low expression of interferon-gamma (IFN-gamma), which has been reported to inhibit IgE production, may explain the elevated levels of IgE in this patient. The results thus highlight the importance of the inhibitory effect of IFN-gamma on regulation of IgE production.
authors.affiliation: Department of Paediatrics, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Melamed
authors.forename: A
authors.initials: A
authors.lastname: Cohen
authors.forename: C M
authors.initials: CM
authors.lastname: Roifman
mesh_terms: D015703:Antigens, CD / Q000032:analysis*; D017252:CD3 Complex / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D016207:Cytokines / Q000032:analysis / Q000235:genetics; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000276:immunology*; D007223:Infant; D015848:Interleukin-5 / Q000032:analysis*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D013601:T-Lymphocytes / Q000737:chemistry / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D016207:Cytokines; D015848:Interleukin-5; D012333:RNA, Messenger; D016693:Receptors, Antigen, T-Cell, alpha-beta