Biomaterial Database

Impaired function of regulatory T-cells in hypersensitivity pneumonitis. 2011

M Girard, and E Israël-Assayag, and Y Cormier

Centre de Recherche de Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 chemin Sainte-Foy, Québec, QC, G1V 4G5, Canada.

Hypersensitivity pneumonitis (HP) is characterised by lung lymphocytosis. Most individuals exposed to HP antigens remain asymptomatic. The mechanisms involved in the impaired immune tolerance leading to HP are unclear. Normally, T-regulatory (Treg)-cells control the immune response. The aim of the present study was to determine whether Treg-cell suppressive function deficiency can explain the uncontrolled inflammation in HP. Bronchoalveolar lavage (BAL) and blood samples were obtained from normal subjects, asymptomatic individuals and HP patients. BAL and blood Treg-cells were isolated. The ability of Treg-cells to suppress T-cell proliferation and the role of interleukin (IL)-17 was verified. BAL and blood Treg-cells from normal subjects suppressed the proliferative response of activated T-cells by 47.1 and 42%, respectively. BAL and blood Treg-cells from asymptomatic subjects had a slightly decreased activity and suppressed proliferation by 29.4 and 31.8%, respectively. BAL and blood Treg-cells from HP patients were totally nonfunctional and unable to suppress proliferation. Low levels of IL-17 were detected in sera and BAL from both normal and asymptomatic individuals, whereas measurable levels were found in patients. Treg-cells may be involved in antigen tolerance in asymptomatic subjects. Defective Treg-cell function, potentially caused by increased IL-17 production, could account for the exacerbated immune response characteristic of HP.

UI	MeSH Term	Description	Entries
D007107	Immune System	The body's defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components.	Immune Systems,System, Immune,Systems, Immune
D007249	Inflammation	A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.	Innate Inflammatory Response,Inflammations,Inflammatory Response, Innate,Innate Inflammatory Responses
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D000542	Alveolitis, Extrinsic Allergic	A common interstitial lung disease caused by hypersensitivity reactions of PULMONARY ALVEOLI after inhalation of and sensitization to environmental antigens of microbial, animal, or chemical sources. The disease is characterized by lymphocytic alveolitis and granulomatous pneumonitis.	Allergic Alveolitis, Extrinsic,Hypersensitivity Pneumonitis,Pneumonitis, Hypersensitivity,Allergic Alveolitides, Extrinsic,Alveolitides, Extrinsic Allergic,Extrinsic Allergic Alveolitides,Extrinsic Allergic Alveolitis,Hypersensitivity Pneumonitides,Pneumonitides, Hypersensitivity
D014409	Tumor Necrosis Factor-alpha	Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.	Cachectin,TNF-alpha,Tumor Necrosis Factor Ligand Superfamily Member 2,Cachectin-Tumor Necrosis Factor,TNF Superfamily, Member 2,TNFalpha,Tumor Necrosis Factor,Cachectin Tumor Necrosis Factor,Tumor Necrosis Factor alpha
D015496	CD4-Positive T-Lymphocytes	A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.	T4 Cells,T4 Lymphocytes,CD4-Positive Lymphocytes,CD4 Positive T Lymphocytes,CD4-Positive Lymphocyte,CD4-Positive T-Lymphocyte,Lymphocyte, CD4-Positive,Lymphocytes, CD4-Positive,T-Lymphocyte, CD4-Positive,T-Lymphocytes, CD4-Positive,T4 Cell,T4 Lymphocyte