CTLs Directed against HER2 Specifically Cross-React with HER3 and HER4

Abstract

The human epidermal growth factor receptor 2 (HER2) has been targeted as a breast cancer-associated Ag by T cell-based immunotherapeutical strategies such as cancer vaccines and adoptive T cell transfer. The prerequisite for a successful T cell-based therapy is the induction of T cells capable of recognizing the HER2-expressing tumor cells. In this study, we generated human cytotoxic T cell clones directed against the HER2369–377 epitope known to be naturally presented with HLA-A*0201. Those HER2-reactive CTLs, which were also tumor lytic, exhibited a similar lysis pattern dividing the targets in lysable and nonlysable tumor cells. Several HER2-expressing tumor cells became susceptible to CTL-mediated lysis after IFN-γ treatment and, in parallel, up-regulated molecules of the Ag-presenting machinery, indicating that the tumor itself also contributes to the success of CTL-mediated killing. Some of the HER2369–377-reactive T cells specifically cross-reacted with the corresponding peptides derived from the family members HER3 and/or HER4 due to a high sequence homology. The epitopes HER3356–364 and HER4361–369 were endogenously processed and contributed to the susceptibility of cell lysis by HER cross-reacting CTLs. The principle of “double” or “triple targeting” the HER Ags by cross-reacting T cells will impact the further development of T cell-based therapies.

A Single TCRα-Chain with Dominant Peptide Recognition in the Allorestricted HER2/neu-Specific T Cell Repertoire

“…The TCR-deficient T cell line Jurkat76 (J76) (13) and J76 transduced with CD8a (J76CD8) cells were used for TCR-transfer experiments. The following malignant cell lines were used as targets to test tumor reactivity and cross-reactivity: HLA-A2-positive breast carcinoma cell lines MCF-7 (ATCC HTB-22) and MDA-MB 231 (CLS, Eppelheim, Germany), the HLA-A2-negative ovarian cancer cell lines SKOV3 and SKOV3 transfected with HLA-A2 (SKOV3tA2) (kindly provided by H. Bernhard, Munich, Germany) (14), the HLA-A2-positive melanoma cell lines SK-Mel 29, 624.38MEL (kindly provided by E. Noessner, Munich, Germany), wild-type (WT) K562 (ATCC CCL-243), HLA-A2-positive 143 TK 2 lung fibroblasts (kindly provided by R. Mocikat, Munich, Germany), MRC-5 lung fibroblasts (CCL-171), and the human B cell lines C1R untransfected and transfected with HLA-A*0201 (kindly provided by S. Stevanovic, Tübingen, Germany) (15). CIR cells transfected with HLA-A p 0201 and HER2, as well as fetal cardiomyocytes, were kindly provided by J. Charo (Berlin, Germany) (16).…”

“…We used the following peptides for pulsing of APCs: the HLA-A2-restricted HER2 369-377 (KIFGSLAFL) (17), single amino acid analog peptides of HER2 369-377 substituting all amino acids at all positions by either alanine or threonine, the HER1-derived peptide 364-372 (SISGDLHIL) (14), the HER3-derived peptide 356-364 (KILGNLDFL) (14), the HER4-derived peptide 361-369 (KINGNLIFL) (14), the HLA-A2-restricted influenza matrix peptide MP58 (GILGFVFTL) (18), the HLA-A2-restricted tyrosinase-derived peptide 369-377 (YMNGTMSQV) (19), the Formin-related protein in leukocytes (FMNL1)-derived HLA-A2-binding peptide PP2 (RLPERMTTL) (8), the HDAC6-derived peptide (RLAERMTTR) (8), the HLA-A2-restricted GP100-derived peptide 209-217 (ITDQVPFSV) (20), and the CMV-phosphoprotein (pp) 65-derived HLA-A2-restricted peptide 495-503 (NLVPMVATV) (21). Peptides were synthesized by standard fluorenylmethoxycarbonyl (Fmoc) synthesis (Biosyntan, Berlin, Germany).…”

HER2/neu: an increasingly important therapeutic target. Part 1: basic biology & therapeutic armamentarium

“…The majority of these have focused on the extracellular domain of HER2/neu due, in large part to the high degree of homology of the intracellular kinase domain with other receptor tyrosine kinases both in and outside of the HER family [209,[215][216][217][218][219], although some strategies have included elements from the intracellular domain [213][214][215]. Indeed, cytotoxic T-lymphocytes directed against HER2/neu have been documented to react with HER3 and HER4 [220].…”

Establishment of specific cytotoxic T lymphocyte culture system and its inhibitory effect on ovarian cancer

“…A 9-amino acid human leukocyte antigen-A2-restricted CTL epitope corresponding to a cleavage site of the HER2/neu tumor antigen was also predicted by the above mentioned software. Finally, the P369-377 peptide epitope, which has previously been shown to be immunocompetent (28)(29)(30)(31), was elected as the antigen peptide from the antigen epitope prediction results. The amino acid sequence of the P369-377 peptide epitope was as follows: Lysine-isoleucine-phenylalanine (Phe)-glycine-serine-leucine (Leu)-alanine-Phe-Leu.…”