Activated lymphocytes from breast cancer patients express the characteristics of type 2 helper cells – a possible role for breast cancer-associated p43

P43, a breast cancer-associated antigen, has been repeatedly described as an immunosuppressive factor. The objective of the present study was to investigate whether immune dysregulation induced by p43 affects the profile of cytokines secreted by mitogen-stimulated lymphocytes in breast cancer patients as compared with stimulated lymphocytes in women with benign tumors. The study consisted of 32 women undergoing surgical excision for a suspicious lesion in their breast. Histology revealed malignant breast disease in 20 patients and benign lesions in 10 patients. Lymphocytes isolated from peripheral blood were activated by Conconavalin A (Con A) with and without the addition of p43 and the concentrations of cytokines (IL-2, TNF- α, IFN- γ, IL-4, IL-10 and IL-6) secreted into the culture medium were determined. Lymphocytes of patients with malignant breast disease stimulated with Con A secreted a significantly higher concentration of IL-10 compared with lymphocytes of patients with benign tumors. No significant differences were found between the two groups regarding the levels of IL-2, TNF- α, IFN- γ and IL-4. Cytokine concentrations were analyzed according to the type 1/type 2 cytokine profile (IL-2, TNF and IFN- γ and IL-4, IL-6 and IL-10, respectively). This analysis revealed no significant differences in IL-2, TNF or IFN- γ between benign and malignant tumors. However, in the type 2 cytokines, lymphocytes from cancer patients secreted significantly higher levels of IL-4 (27.3±7.2 U/ml) and IL-10 (44.1±22.3 U/ml) than did the lymphocytes from patients with benign disease (21.4±7.3 and 1.8±0.3 U/ml, respectively). The addition of p43 to the culture medium significantly enhanced the levels of IL-4 secreted by lymphocytes in both groups of patients (malignant disease, from 27.3±9.2 to 40.7±6.3 U/ml; benign disease, from 21.4±7.3 to 28.4±2.1 U/ml). P43 antigen significantly enhanced the low levels of IL-10 in the benign lymphocytes (from 1.8±0.4 to 8.4±1.5 U/ml) while the high levels of IL-10 secreted by the PBL in patients with malignant tumors were not significantly increased (44.1±22.3 versus 50.1±12.6 U/ml). The study showed a difference in the immune response of lymphocytes between malignant and benign tumors. When the current results were analyzed according to the type of response, i.e. in terms of whether at least two cytokines of either type 1 or type 2 were elevated, a significant type 2 response was observed in the PBL of patients with malignant brea