Concomitant Targeting of Tumor Cells and Induction of T-cell Response Synergizes to Effectively Inhibit Trastuzumab-Resistant Breast Cancer

3059 Background: Studies have demonstrated that the level of HER2 gene amplification in breast cancer, assessed by fluorescence in situ hybridization (FISH), correlates with favorable clinical response after treatment with trastuzumab. We questioned whether HER2 gene amplification impacted the development of HER2-specific T-cell immunity following immunization with a HER2 vaccine. Methods: Patients with HER2+ stage III or IV breast cancer, treated to complete remission or stable bone only disease, were enrolled in one of two concurrent clinical trials of HER2-specific vaccines. Eligibility criteria between the two studies were similar. Patients received either a plasmid DNA-based vaccine encoding the HER2 intracellular domain or a peptide-based vaccine composed of 3 HER2 class II epitopes. Peripheral blood was assessed for HER2-specific T-cell responses by interferon gamma (IFN-g) ELISPOT prior to, immediately after, and 6 months to 1 year after the end of vaccinations. Both immune response and FISH data were available on 31 patients. Results: Correlation of FISH levels to IFN-g spots/well in evaluable patients revealed the level of HER2 gene amplification was not related to the presence of pre-existent HER2-specific T-cell immunity prior to vaccination (p=0.43), the generation of a HER2-specific immune response after vaccination (p=0.35), or the persistence of the HER2-specific T-cell response (p=0.33). However, the magnitude of the T-cell response achieved was less as HER2 gene amplification increased (p=0.05). Conclusions: The level of HER2 gene amplification in the primary tumor can adversely impact the magnitude of HER2-specific T-cell immunity achieved after vaccination. No significant financial relationships to disclose.

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Impact of Regulatory T Cells on Antigen Specific T Cell Response Using Recombinant Chimeric T Cell Receptors In Vivo.

Blood ◽

10.1182/blood.v108.11.5475.5475 ◽

2006 ◽

Vol 108 (11) ◽

pp. 5475-5475

Author(s):

David M. Kofler ◽

Markus Chmielewski ◽

Heike Koehler ◽

Tobias Riet ◽

Patrick Schmidt ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Tumor Cells ◽

T Cell Receptors ◽

Cell Response ◽

Effector T Cells ◽

T Cell Response ◽

Cell Receptors

Abstract Recombinant T cell receptors with defined specificity against tumor cells are a promising experimental approach in the elimination of residual leukemia and lymphoma cells. It is so far unresolved whether regulatory T cells with suppressor activities impair the efficiency of cytolytic T cells grafted with a recombinant immunoreceptor. The frequency of regulatory T cells is highly increased in tumor patients and their suppressive function seems to play a role in the fail of an autologous T cell response against the malignant cells. In this study we analyzed the antigen-triggered, specific activation of receptor grafted T cells in the presence or absence of regulatory CD4+CD25high T cells. CD3+ T cells were grafted with CEA-specific immunoreceptors containing the CD3-zeta signaling domain for T cell activation. Co-cultivation of receptor grafted effector T cells together with regulatory T cells repressed proliferation of the effector cells and decreased IL-2 secretion. Secretion of IFN-gamma and IL-10 was not impaired. Interestingly, the cytotoxicity of grafted effector T cells towards CEA-expressing tumor cells was not impaired by regulatory T cells in vitro. To evaluate the relevance in vivo, we used a Crl:CD1 Nu/Nu mouse model to assess growth of CEA+ tumor cells in the presence of receptor grafted effector T cells and of regulatory T cells. Mice inoculated with tumor cells together with CD3+ effector T cells without immunoreceptor and regulatory T cells developed earlier tumors with faster growth kinetics compared to mice that were inoculated with tumor cells, CD3+ T cells and CD4+CD25- control T cells. Using effector T cells that were equipped with a recombinant CEA-specific CD3-zeta immunoreceptor, 2 of 5 mice developed a tumor in the presence of regulatory T cells while none of the mice developed a tumor in the absence of regulatory T cells. Taken together, regulatory T cells obviously impair an antigen-specific, anti-tumor T cell attack in vivo. This seems to be due to repression of proliferation of the effector T cells and not to diminished cytotoxicity. These findings have major impact on the design of clinical studies involving adoptively transferred effector T cells.

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Apoptotic tumor cells are superior to tumor cell lysate, and tumor cell RNA in induction of autologous T cell response in B-CLL

Leukemia ◽

10.1038/sj.leu.2403517 ◽

2004 ◽

Vol 18 (11) ◽

pp. 1810-1815 ◽

Cited By ~ 47

Author(s):

P Kokhaei ◽

A Choudhury ◽

R Mahdian ◽

J Lundin ◽

A Moshfegh ◽

...

Keyword(s):

T Cell ◽

Tumor Cell ◽

Tumor Cells ◽

Cell Response ◽

T Cell Response ◽

Cell Lysate ◽

Tumor Cell Lysate

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P11.10 The IFNγ pathway mediates brain metastasis formation of breast cancer

Neuro-Oncology ◽

10.1093/neuonc/noz126.156 ◽

2019 ◽

Vol 21 (Supplement_3) ◽

pp. iii44-iii44

Author(s):

R Pedrosa ◽

J M Kros ◽

B Schrijver ◽

R Marques ◽

P Leenen ◽

...

Keyword(s):

Breast Cancer ◽

T Cells ◽

T Cell ◽

T Lymphocytes ◽

Cancer Cells ◽

Tumor Cells ◽

Breast Cancer Cells ◽

T Cell Response ◽

Activated T Cells

Abstract BACKGROUND In previous work we showed the prominence of the T-cell response in the formation of brain metastases of primary ER negative breast cancers (Mustafa et al, Acta Neuropathol 2018). We also showed that breast cancer cells co-cultured with stimulated T lymphocytes overexpress Guanylate-binding protein 1 (GBP1) accompanying increased trespassing ability through an in vitro blood-brain barrier (BBB) model. In addition, we demonstrated a predilection for metastasizing to brain of breast cancer cells that were co-cultured with activated T cells in a mouse model. We now scrutinize the importance of the IFNγ pathway for tresspassing of the tumor cells through the BBB following T cell contact. MATERIAL AND METHODS Anti-hIFN-γ-IgA antibodies were used to neutralize the IFNγ effects on the tumor cells. The effects on the tumor cells is only due to native IFNγ produced by activated T cells, not by recombinant IFNγ. Since the IFNγ expression itself enhances its expression by the T cells, we blocked IFNγ receptors prior to adding CD3+ T cell conditioned media to the breast cancer cells. The receptor blocking was achieved by antibodies to the IFNγα and IFNγβ subunits. Activation of the STAT1 pathway was monitored by GBP1 expression. For functional read-out the in vitro BBB model was used. RESULTS The presence of T-lymphocyte-secreted IFNγ in the primary breast cancer microenvironment activates the STAT1-dependent IFNγ pathway in breast cancer cells, endowing them with an increased ability to trespass the in vitro BBB. Moreover, direct inhibition of soluble IFNγ, or blocking of the IFNγ-specific receptor in breast cancer cells significantly decreases their ability to cross the BBB. CONCLUSION The results illustrate the specific action of T lymphocytes in the formation of cerebral metastasis involves the IFNγ signaling pathway as one of the crucial entangled pathways Subsequent studies should aim at the interference with the IFNγ pathway to develop preventive strategies against the formation of cerebral metastases of breast cancer.

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CD47/SIRPα blocking peptide identification and synergistic effect with irradiation for cancer immunotherapy

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-000905 ◽

2020 ◽

Vol 8 (2) ◽

pp. e000905 ◽

Cited By ~ 1

Author(s):

Hongfei Wang ◽

Yixuan Sun ◽

Xiuman Zhou ◽

Chunxia Chen ◽

Ling Jiao ◽

...

Keyword(s):

Immune Response ◽

Amino Acid ◽

T Cell ◽

Cancer Immunotherapy ◽

Tumor Cells ◽

Cell Response ◽

Regulatory Protein ◽

T Cell Response ◽

Antitumor Effects ◽

Pathogen Invasion

BackgroundImmunotherapy has achieved remarkable advances via a variety of strategies against tumor cells that evade immune surveillance. As important innate immune cells, macrophages play important roles in maintaining homeostasis, preventing pathogen invasion, resisting tumor cells and promoting adaptive immune response. CD47 is found to be overexpressed on tumor cells and act as a don’t eat me’ signal, which contributes to immune evasion. Macrophages mediated phagocytosis via blockade CD47/SIRPα (signal regulatory protein alpha) interaction was proved to induce effective antitumor immune response.MethodsA novel peptide pep-20, specifically targeting CD47 and blocking CD47/SIRPα interaction, was identified via high-throughput phage display library bio-panning. The capability to enhance the macrophage-mediated phagocytosis activities and antitumor effects of pep-20 were investigated. The mechanism of pep-20 to induce T-cell response was explored by ex vivo analysis and confirmed via macrophage depleting strategy. The structure-activity relationship and D-amino acid substitution of pep-20 were also studied. The antitumor effects and mechanism of a proteolysis resistant D-amino acid derivate pep-20-D12 combined with irradiation (IR) were also investigated.ResultsPep-20 showed remarkable enhancement of macrophage-mediated phagocytosis to both solid and hematologic tumor cells in vitro, and inhibited tumor growth in immune-competent tumor-bearing mice. Furthermore, pep-20 promoted macrophages to mobilize the antitumor T-cell response with minimal toxicity. Furthermore, systemic administration of the derivate pep-20-D12 showed robust synergistic antitumor efficacy in combination with IR.ConclusionIn summary, these results demonstrated that CD47/SIRPα blocking peptides, pep-20 and its derivate, could serve as promising candidates to promote macrophages-mediated phagocytosis and immune response in cancer immunotherapy.

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