Distribution and cytokine production of CD4 and CD8 T-lymphocyte subsets in patients with acute asthma attacks

CD8+ T cell contributions to allergen induced pulmonary inflammation and airway hyperreactivity

“…This suggests a role for these cells in the asthmatic response, which has previously been hypothesized to be mainly CD4 + T cell driven [19]. It has been shown that in both patients with stable asthma and those experiencing acute asthma attacks there are more CD4 + T cells than CD8 + T cells in peripheral blood and induced sputum [20,21]. While CD8 + cells can produce type 2 cytokines [6], respond to exogenous antigen [5], and cause an asthmatic response [22], they are not the only cell type able to do so.…”

“…This is reflected in AHR data that show a significant decrease, but not a complete abrogation, of AHR when CD8 + T cells are depleted. However, in the BAL fluid of patients experiencing acute asthma attacks, there is an increased number of T cells, and the CD4/CD8 ratio is decreased when compared to stable asthmatics [20,21], suggesting that CD8 + T cells participate in the airway response. Additionally, findings in the lungs of patients suffering from asthmatic death show a predominance of CD8 + T cells [1], and a reversal of the CD4:CD8 ratio in the airways [23].…”

Intracellular production of IL-2, IL-4 and IFN-? by peripheral blood CD3+ cells in intermittent allergic rhinitis

“…A higher production of IL-4 and IL-5 by CD4 + T cells as compared to CD8 + T cells was observed in asthmatic patients [22]. However, in that study cytokine production was assessed in culture supernatants of purified cells isolated from peripheral blood by means of ELISA, not by flow cytometry.…”

High IFN-γ production by CD8+ T cells and early sensitization among infants at high risk of atopy

“…32,33 Moreover, asthma severity in both children 34 and adults 35 has been linked with excessive IFN-c production, in particular by CD8 + T cells, 34,35 and bronchoalveolar lavage studies suggest preferential recruitment of CD8 + T cells (relative to CD4 + T cells) into the airways during acute asthma exacerbations. 36 A recent study using class I MHC tetramer technology has also implicated CD8 + T cells responsive to Der p 1 allergen as determinants of the severity of allergic disease in HDM-sensitized adults. 37 In a previous study, we demonstrated that although expression of the IFN-c gene is developmentally constrained in neonatal CD4 + T cells via hypermethylation of CpG dinucleotide sites in the proximal promoter, this control mechanism does not appear to operate to the same degree in neonatal CD8 + T cells, which are capable of production of IFN-c at levels close to the adult normal range.…”