title: Role of gamma/delta T cells in a patient with CD4+CD3- lymphocytosis, hypereosinophilia, and high levels of IgE.
abstract: BACKGROUND
  CD4+CD3- T cells have previously been shown to play a pathogenic role in the hypereosinophilic syndrome by secreting IL-5 and IL-4.
  
  
  OBJECTIVE
  The goal of this study was to study the role of CD4+CD3- and other T-cell subsets in a patient with eosinophilia, dermatitis, and a high level of IgE (100,000 IU/mL) in the serum.
  
  
  METHODS
  We isolated PBMCs and performed flow cytometry, cell cultures, and in vitro assays of Ig, lymphokine production, and cell-mediated cytotoxicity.
  
  
  RESULTS
  Flow cytometric and immunohistochemical analysis of the PBMCs revealed a major population (consisting of approximately 85% of the CD4+ T cells) that lacked expression of CD3 and T-cell receptors on the cell surface (CD4+CD3- T cells), but did express CD3 peptides in the cytoplasm. Activation of the PBMCs in vitro resulted in a 100-fold greater than normal release of IL-4, whereas IFN-gamma production was less than normal, suggesting a predominantly type 2 helper functional phenotype of the CD4+CD3- T cells. Importantly, both CD4-CD8(low) Vdelta1+ T-cell receptor gammadelta+ and CD4+CD3- T cells were cultured from the PBMCs. The former secreted IFN-gamma exclusively, whereas the latter secreted both IL-4 and IFN-gamma. Furthermore, only the T-cell receptor gammadelta+ lymphocytes were cytotoxic to autologous B-lymphoblastoid cells and specifically inhibited IgE production in cultures of autologous polyclonally stimulated PBMCs.
  
  
  CONCLUSIONS
  The results suggest that CD8(low) Vdelta1+ T-cell receptor gammadelta+ clones functionally counteract IgE-inducing effects of type 2 CD4+CD3- helper cells in this patient with hypereosinophilic syndrome.
authors.affiliation: Department of Medicine, Chaim Sheba Medical Center, Sackler School of Medicine, Tel Hashomer, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Bank
authors.forename: A
authors.initials: A
authors.lastname: Reshef
authors.forename: M
authors.initials: M
authors.lastname: Beniaminov
authors.forename: E
authors.initials: E
authors.lastname: Rosenthal
authors.forename: G
authors.initials: G
authors.lastname: Rechavi
authors.forename: Y
authors.initials: Y
authors.lastname: Monselise
mesh_terms: D000328:Adult; D017252:CD3 Complex / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002469:Cell Separation; D002478:Cells, Cultured; D004802:Eosinophilia / Q000150:complications / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008218:Lymphocytosis / Q000150:complications / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D013601:T-Lymphocytes / Q000737:chemistry / Q000276:immunology*
chemical_list: D017252:CD3 Complex; D016692:Receptors, Antigen, T-Cell, gamma-delta; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma