Background: Evidences from mice and humans indicate that T cells could be relevant in recognition of stress-induced self and/or yet-unidentified inhaled foreign antigens. Their specificity differ from classical MHC-restricted T cells, and involves the immunoglobulin-like structure of the T-cell receptor with the recognition of small organic molecules, alkilamines and self lipid compounds presented by CD1+ dendritic cells. Objective: Since CD1 receptors are mainly devoted to lipid antigen presentation, we sought to determine if exogenous pollen membrane lipids may act as allergens for CD1-restricted T cells Methods: Peripheral blood and nasal mucosa-associated T cells were cloned from normal controls (chronic vasomotor rhinitis) and cypress-sensitive subjects, tested for their antigen specificity and CD1-restriction with phospholipids (PLs) extracted from tree pollen grains, as well with other natural or synthetic compounds. PLs-reactivity of cloned T cells was measured by mean of proliferative response and cytokine release, as well as by testing their helper activity on IgE production in vitro and in vivo. Results: Cloned T lymphocytes from allergic subjects, but not normal controls, were found to recognize pollen-derived phosphatidyl-ethanolamine (PE) in a CD1d-restricted fashion. Only 16:0/18:2 and 18:2/18:2 PE were stimulatory, whereas no response was recorded for disaturated PE, phosphatidylcholine, neutral lipids or protein extract. Proliferating clones secreted both TH1- and TH2-type cytokines and drive IgE production in vitro and in vivo. Conclusion: CD1d-restricted T cells specific for PLs can represent a key mucosal regulatory subset for the control of early host reactivity against tree pollens. Capsule summary: This is the first description of pollen membrane lipid recognition as antigens by human mucosal T cells from allergic subjects, in a CD1d-restricted manner. Phospholipid interaction with CD1+ dendritic cells can broaden our possibilities in understanding and controlling allergic diseases.
Recognition of pollen-derived phosphatidylethanolamine by human CD1d-restricted gd T cells
CORAZZI, Lanfranco;SPINOZZI, Fabrizio
2006
Abstract
Background: Evidences from mice and humans indicate that T cells could be relevant in recognition of stress-induced self and/or yet-unidentified inhaled foreign antigens. Their specificity differ from classical MHC-restricted T cells, and involves the immunoglobulin-like structure of the T-cell receptor with the recognition of small organic molecules, alkilamines and self lipid compounds presented by CD1+ dendritic cells. Objective: Since CD1 receptors are mainly devoted to lipid antigen presentation, we sought to determine if exogenous pollen membrane lipids may act as allergens for CD1-restricted T cells Methods: Peripheral blood and nasal mucosa-associated T cells were cloned from normal controls (chronic vasomotor rhinitis) and cypress-sensitive subjects, tested for their antigen specificity and CD1-restriction with phospholipids (PLs) extracted from tree pollen grains, as well with other natural or synthetic compounds. PLs-reactivity of cloned T cells was measured by mean of proliferative response and cytokine release, as well as by testing their helper activity on IgE production in vitro and in vivo. Results: Cloned T lymphocytes from allergic subjects, but not normal controls, were found to recognize pollen-derived phosphatidyl-ethanolamine (PE) in a CD1d-restricted fashion. Only 16:0/18:2 and 18:2/18:2 PE were stimulatory, whereas no response was recorded for disaturated PE, phosphatidylcholine, neutral lipids or protein extract. Proliferating clones secreted both TH1- and TH2-type cytokines and drive IgE production in vitro and in vivo. Conclusion: CD1d-restricted T cells specific for PLs can represent a key mucosal regulatory subset for the control of early host reactivity against tree pollens. Capsule summary: This is the first description of pollen membrane lipid recognition as antigens by human mucosal T cells from allergic subjects, in a CD1d-restricted manner. Phospholipid interaction with CD1+ dendritic cells can broaden our possibilities in understanding and controlling allergic diseases.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
