Background: Proteins of the fungus Trichophyton tonsurans have been shown to give strong T cell proliferative responses in vitro using lymphocytes from individuals with immediate or delayed skin tests. Furthermore, Trichophyton-specific T-cell lines produce distinct patterns of cytokine production depending upon the skin-test reactivity of the host. However, skin-test negative individuals generally give limited responses. A recent study has demonstrated dust mite specific proliferation with lymphocytes from atopic and non-atopic subjects using the serum free medium Aim V.
Objective: Compare the T-cell reactivity to Trichophyton and dust mite antigens in Aim V and media containing 10% pooled AB serum.
Methods: Peripheral blood mononuclear cells (PBMC) were separated from subjects with different skin-test reactivities and cultured either in media with serum or serum free media.
Results: Proliferation to two Trichophyton extracts was decreased in serum free media among subjects with either immediate or delayed hypersensitivity. Trichophyton skin-test negative subjects gave poor proliferative responses in both culture conditions. A similar decrease in proliferation in serum free media was observed in cultures with PHA and tetanus toxoid. In contrast, the majority of individuals showed increased proliferation to dust mite antigens when cultured in serum free media. Cultures in serum free medium produced less IFNgamma, IL-4, or IL-5 compared with cultures in AB medium.
Conclusions: In vitro T-cell responses to the dermatophyte fungus T. tonsurans are inhibited by the serum free medium Aim V. This inhibition is seen equally with cells from individuals with delayed and immediate hypersensitivity. Furthermore, the results do not support the view that AB serum is masking T-cell responses in skin-test negative individuals.