CD8+ T-cell maturation following lung transplantation: the differential impact of CMV and acute rejection.
Studies on persistent viral infections demonstrate that CD8(+) T-cells differentiate along distinct pathways following chronic antigen exposure; however the effect of stimulation with non-viral chronic antigens is poorly described. We assessed the contributions that the presence of an allograft or cytomegalovirus (CMV) has on the post-thymic differentiation of CD8(+) T-cells in both the blood and lung allograft in patients undergoing lung transplantation. CD28 expression on blood CD8(+) T-cells was reduced in CMV seropositive patients, and was further reduced following acute episodes of CMV reactivation. These viral-associated changes in phenotype were not seen in CD8(+) T-cells isolated from the lung allograft where a different pattern of CD28 expression was observed. Following transplantation there was a progressive reduction in CD28 expression on BAL CD8(+) T-cells. In contrast to what was observed in peripheral blood, reduced CD28 expression on BAL CD8(+) T-cells was associated with a reduced gamma-IFN production. Furthermore, a high proportion of CD28-CD8(+) T-cells in the BAL was associated with fewer episodes of acute allograft rejection. An expanded CD28-CD8(+) T-cell subset, with reduced function, within the lung allograft may have important prognostic implications in lung transplant recipients.
Westall
G P
GP
Heart and Lung Transplant Unit, Department of Allergy Immunology and Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, 3181, Australia. G.Westall@alfred.org.au
Brooks
A G
AG
Kotsimbos
T
T
D000328:Adult; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology / Q000821:virology; D018106:CD28 Antigens / Q000096:biosynthesis / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D003430:Cross-Sectional Studies; D003587:Cytomegalovirus / Q000276:immunology / Q000302:isolation & purification*; D003586:Cytomegalovirus Infections / Q000097:blood / Q000276:immunology*; D005260:Female; D006084:Graft Rejection / Q000097:blood / Q000276:immunology* / Q000821:virology; D006801:Humans; D008137:Longitudinal Studies; D016040:Lung Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019562:Viral Load
D018106:CD28 Antigens