Blockade of CD28/B7 co-stimulation by mCTLA4-Hgamma1 inhibits antigen-induced lung eosinophilia but not Th2 cell development or recruitment in the lung

Eur J Immunol. 1997 Jan;27(1):155-61. doi: 10.1002/eji.1830270123.


We have studied the role of the CD28/B7 co-stimulatory pathway in the development of a Th2-type lung immune response. Mice injected two or three times intraperitoneally with ovalbumin in alum adjuvant and then re-exposed to the same antigen by intranasal (i.n.) inoculation show infiltration of the lung tissue and appearance in the broncho-alveolar lavage (BAL) fluid of significant numbers of eosinophils and lymphocytes, in a pattern which is reminiscent of asthmatic inflammation. The accumulation of eosinophils in the airways is completely dependent on interleukin (IL)-5 secretion by CD4+ T cells. We have used mice transgenic for a soluble form of murine CTLA-4 (mCTLA4-Hgamma1) which binds to B7 molecules on antigen-presenting cells, thereby preventing their interaction with T cell-expressed CD28. mCTLA4-Hgamma1-transgenic mice immunized intraperitoneally and challenged i.n. with ovalbumin failed to generate any eosinophil infiltration, suggesting that little or no IL-5 was secreted in the lungs of these mice. In contrast with the complete lack of eosinophils, the numbers and phenotypes of infiltrating lymphocytes were comparable in the lungs of mCTLA4-Hgamma1-transgenic and normal mice. Also, lung lymphocytes from immunized mCTLA4-Hgamma1-transgenic and normal mice could be shown to secrete comparable amounts of IL-4 and IL-5 when stimulated in culture in the absence of mCTLA4-Hgamma1. We conclude that mCTLA4-Hgamma1 can efficiently block the production of IL-5 during in vivo responses and inhibit eosinophil recruitment, but that it does not block the development of CD4+ T cells into Th2 cells with the potential to secrete IL-5.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abatacept
  • Animals
  • Antigens, CD
  • Antigens, Differentiation / physiology*
  • B7-1 Antigen / physiology*
  • Bronchoalveolar Lavage Fluid / cytology
  • CD28 Antigens / physiology*
  • CTLA-4 Antigen
  • Female
  • Immunoconjugates*
  • Interleukin-5 / physiology
  • Lung / immunology*
  • Lung / pathology
  • Lymphocyte Activation
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Ovalbumin / immunology
  • Signal Transduction
  • Th2 Cells / immunology*


  • Antigens, CD
  • Antigens, Differentiation
  • B7-1 Antigen
  • CD28 Antigens
  • CTLA-4 Antigen
  • Ctla4 protein, mouse
  • Immunoconjugates
  • Interleukin-5
  • Abatacept
  • Ovalbumin