Establishment and characterization of alpha s1-casein-specific T-cell lines from patients allergic to cow's milk: unexpected higher frequency of CD8+ T-cell lines.

Abstract

To study cow's milk allergy at the cellular level, we assessed the reactivity of peripheral blood mononuclear cells from patients allergic to cow's milk to alpha s1-casein, which is one of the major allergens in cow's milk. Proliferation of the cells to alpha s1-casein activation showed a rather weak response. Therefore to understand T-cell reactivity to alpha s1-casein in more detail, we prepared alpha s1-casein-specific T-cell lines from patients allergic to cow's milk and established 26 T-cell lines. These T-cell lines could be classified into three groups by analyzing their surface marker expression: those containing predominantly CD4+ CD8- T cells, those containing both CD4+CD8- and CD4-CD8+ T cells, and those containing predominantly CD4- CD8+ T cells. The CD8+ T cells were obtained at an unexpectedly higher frequency from the patients. These T-cell lines produced interferon-gamma and IL-4. These results suggest that CD8+ T cells specific for alpha s1-casein and CD4+ T cells were primed by the stimulation with alpha s1-casein in patients allergic to milk and that both T cells may play a key role in the onset, progression of, or recovery from cow's milk allergy.