Phenotypic characterization of T lymphocytes emigrating into lung tissue and the airway lumen after antigen inhalation in sensitized mice.
Cytokines released from CD4+ T lymphocytes contribute to the pathogenesis of asthma by influencing the differentiation and function of eosinophils, the primary effector cells that cause airway epithelial damage. Using a model of ovalbumin (OA)-induced, eosinophil-rich chronic lung inflammation in sensitized mice, we have defined the role of T lymphocytes further by using three-color flow cytometry to characterize the adhesion and activation antigens that may be associated with the migration of these cells into the lung and airway lumen. OA inhalation in OA-sensitized C57BL/6 mice resulted in an early (6 to 24 h) influx of neutrophils into the bronchial lumen as enumerated by bronchoalveolar lavage (BAL), which was followed by a marked accumulation of lymphocytes and eosinophils between 24 to 72 h. Phenotypic analysis of BAL or lung tissue T cells showed that most Thy-1 CD3+ T cells were CD4+ (CD4: CD8 ratio of 3 to 4:1). The majority (90%) of the T cells in lung or BAL fluid expressed alpha beta T-cell receptors (TCR). Only 3 to 7% of the T cells were gamma delta TCR+ even though almost 25% of the T cells were CD4- CD8-. There were very few natural killer (NK) or B cells in BAL fluid compared with 15% B cells in dissagregated lung tissue. In contrast to T cells in spleen, almost all the lung and BAL T cells were of the memory phenotype, as ascertained by the expression of high levels of CD44 and by the absence of L-selectin and CD45RB on the cell surface. Fifty to ninety percent of lung and BAL T cells from vehicle-sensitized or OA-sensitized and challenged mice expressed the adhesion molecules CD11a (LFA-1), CD54 (ICAM-1), and CD49d (VLA-4). The early T-cell activation marker CD69 was upregulated on 30% of the lung and BAL T cells in OA-sensitized mice after antigen inhalation. When BAL fluid T cells from OA-sensitized and challenged mice were analyzed for their coexpression of adhesion and/or activation molecules, 75% of the cells that expressed one of three adhesion molecules, CD54, CD49d, or CD11a, also expressed at least one of the other two antigens. At least 15% of BAL T cells had all three of these molecules on their cell surfaces. The OA-dependent, temporally regulated emigration of T cells into the bronchial lumen after exposure to aerosolized antigen may be correlated with the accumulation of cells that express the memory phenotype with enhanced expression of adhesion molecules.
Kennedy
J D
JD
Upjohn Laboratories, Kalamazoo, Michigan 49001, USA.
Hatfield
C A
CA
Fidler
S F
SF
Winterrowd
G E
GE
Haas
J V
JV
Chin
J E
JE
Richards
I M
IM
D000281:Administration, Intranasal; D000818:Animals; D017951:Antigen Presentation; D015815:Cell Adhesion Molecules / Q000032:analysis; D002465:Cell Movement; D005260:Female; D016130:Immunophenotyping; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D008168:Lung / Q000276:immunology / Q000473:pathology*; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology*; D012137:Respiratory System / Q000276:immunology / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology
D015815:Cell Adhesion Molecules; D010047:Ovalbumin