Expression of transforming growth factor-beta but not tumor necrosis factor-alpha, interferon-gamma, and interleukin-4 in granulomatous lung lesions in tuberculosis

The expression of transforming growth factor (TGF-beta1), tumor necrosis fa ctor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and interleukin-4 (IL- 4) were assessed in lung tissues from patients with tuberculosis. Vimentin, a constitutively expressed cellular protein, was present in 12 of 19 tissu e sections indicating adequate preservation of tissue proteins in these cas es. Immunohistochemical studies for cytokines were done in the vimentin pos itive sections only. TGF-beta1 was localized to mononuclear phagocytes of t uberculous lung lesions in 4 of 12 tuberculosis patients. TNF-alpha, IFN-ga mma, and IL-4 were absent in sections from all tuberculosis patients. The f ailure to detect the latter cytokines may indicate that these molecules may not be expressed at the site of disease, or are not a feature of the late stages of tuberculous granulomas. TGF beta -1, although not universally exp ressed, may be involved in the development and/or consequences of tuberculo us granuloma formation. These data substantiate further the role of TGF-bet a1 in the immunopathology of tuberculosis, (C) 2000 Harcourt Publishers Ltd .