Tc2 cells respond to soluble antigen in the respiratory tract and induce lung eosinophilia and bronchial hyperresponsiveness

Eur J Immunol. 2004 Sep;34(9):2599-608. doi: 10.1002/eji.200425018.


The key role of T helper 2 (Th2) cells in asthma is well established. In contrast, the function of CD8+ T cells producing a distinct cytokine profile similar to Th2 cells is largely unknown. To analyze a potential role of CD8+ T cell subsets, allergen-specific, in vitro-differentiated T cytotoxic (Tc1 or Tc2) cells from T cell receptor transgenic OT-I mice were adoptively transferred into naive C57BL/6 mice. Subsequent allergen challenge of mice injected with Tc1 cells (producing IFN-gamma but no IL-4) resulted in a neutrophilic airway inflammation without induction of bronchial hyperresponsiveness (BHR). In contrast, the inflammatory response of recipients of adoptively transferred Tc2 cells (producing high levels of IL-4 but little IFN-gamma) was characterized by significantly increased numbers of eosinophils and induction of BHR to methacholine. The response of antigen-specific CD8+ T cells to soluble antigen was also observed in an in vitro system. A low concentration of antigen was shown to favor the generation of Tc2 cells, whereas high antigen load resulted in the differentiation of Tc1 cells. Thus, allergen-specific Tc2 cells respond to inhaled soluble antigen, produce an inflammatory response qualitatively similar to Th2 cells and therefore may exacerbate the Th2-driven airway inflammation in asthma.

MeSH terms

  • Adoptive Transfer
  • Animals
  • Antigens / immunology*
  • Bronchial Hyperreactivity / etiology*
  • Eosinophilia / etiology*
  • Interferon-gamma / biosynthesis
  • Interleukin-4 / biosynthesis
  • Lung / immunology*
  • Mice
  • Mice, Inbred C57BL
  • T-Lymphocytes, Cytotoxic / immunology*
  • Th1 Cells / immunology
  • Th2 Cells / immunology


  • Antigens
  • Interleukin-4
  • Interferon-gamma