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Overexpression of gp185^erbB-2 has been associated with reduced survival in breast-cancer patients. Our earlier results, now confirmed in a larger cohort of patients (798), evidenced that the HLA-A2 allele may participate in the modulation of the erbB-2 tumor phenotype in vivo. In the present study, we evaluated other clinico-biopathologic parameters possibly involved in the host immune response against erbB-2. Localization of the CD3⁺ T-cell infiltrate was taken into consideration in 705 primary breast tumors, and expression of HLA-class-I and HLA-A2 antigens was evaluated in a subgroup of 170 frozen primary tumors of HLA-A2-positive patients. The presence or the absence of HLA-class-I and HLA-A2 antigens in primary tumors did not correlate with erbB-2 expression. However, HLA-A2-positive tumors preferentially showed intratumoral lymphocyte localization, whereas the lesions displaying undetectable HLA-class-I expression showed peritumoral CD3⁺ T-cell localization. Taking into account erbB-2 immunoreactivity, we found that the relationship between HLA-A2 expression and intratumoral CD3⁺ T-lymphocyte localization is significant only in the erbB-2 negative subset, whereas the relationship between lack of HLA-class-I expression and peritumoral CD3⁺ T-lymphocyte localization is significant only in the erbB-2-positive subset. These data provide novel in vivo evidence of the possible contribution of the host immune system to control of erbB-2 oncogene overexpression in breast cancer. Int. J. Cancer (Pred. Oncol.) 84:598–603, 1999. © 1999 Wiley-Liss, Inc.

The main linear epitopes of p-glutathione transferase (p-GST, EC 2.5.1.18), an enzyme related to cancer progression in a restricted number of tumours, were identified by testing in ELISA the reactivities of polyclonal anti-p-GST rabbit sera against a panel of 51 overlapping decapeptides, covering the whole 216-residue sequence of the protein. Several major reactivity peaks were detected, each covering two or three adjacent peptides. The most active fragments were then reconstructed by conventional solid-phase synthesis, linked to Sepharose, and used as affinity ligands for isolating specific anti-p-GST antibody subsets.

Peripheral blood mononuclear cells (PBMC) from both nonatopic and Parietaria officinalis -sensitive donors proliferated in response to the allergen Par o 1 and developed into Par o 1-specific T cell lines and clones, which also showed reactivity for Par o 1-derived peptides. Virtually all Par o 1-specific T cell lines and large numbers of Par o 1-specific T cell clones proliferated in response to two Par o 1 nonapeptides (p92 and p96), which probably contain immunodominant epitopes of the Par o 1 allergen. Both p92- and p96-specific T cell clones showed the ability to produce IFN-γ, but p92-specific T cell clones produced significantly lower amounts of IL-4 and IL-5 than p96-specific T cell clones, indicating that distinct epitopes, able to elicit functionally different T helper cell responses, may coexist in Par o 1. How ever, p92-specific T cell clones derived from atopic subjects with high IgE serum levels (high IgE producers) secreted significantly higher amounts of IL-4 and IL-5 than corresponding T cell clones generated from non atopic subjects or patients with low IgE serum levels (low IgE producers), whereas p96-specific T cell clones secreted high IL-4 and IL-5 concentrations irrespective of whether they derived from high or low IgE producers. The addition of IL- 4 and anti-IL-12 mAb to bulk culture significantly up-regulated the development of p92-specific T cells into IL-4-producing cells, whereas the addition of IL-12 and anti-IL-4 mAb shifted the differentiation of p96-specific T cells towards IFN-γ-producing cells. Taken together, these results suggest that the cytokine profile of allergen-specific T cells is influenced by both the T cell receptor repertoire and the severity of atopic status and can be modulated, at least in vitro, by stimulation with the specific peptide in the presence, or after removal, of appropriate cytokines.