e The levels of IL-10 and TGF- in the serum of mice were assayed by enzyme-linked immunosorbent assay (ELISA). as soon as these immunized mice were challenged with HCC cells, accompanied by T cell and NK cell activation and infiltration. Additionally, immunization with this vaccine decreased the generation of Tregs and the production of TGF- and IL-10. Importantly, STAT3-clogged whole HCC cell lysates prevented HCC-mediated exhaustion of T cells and NK cells, showing low manifestation of checkpoint molecules such as PD-1 and TIGIT on T cells and NK cells in the immunized mice. Conclusions The newly generated STAT3-clogged whole-cell HCC vaccine offers potential for tumor cell vaccination. Electronic supplementary material The online version of this article (10.1186/s13046-017-0623-0) contains supplementary material, which is available to authorized users. strong class=”kwd-title” Keywords: Tumor vaccine, STAT3, Hepatoma, Immunotherapy, Whole-cell vaccine Background Hepatocellular carcinoma (HCC) is the most common main liver malignancy, with high morbidity and mortality, and is the third leading Lomeguatrib cause of cancer-related death worldwide. Traditional methods to treat HCC include surgery treatment, radiotherapy, and chemotherapy . However, the effectiveness of these treatments is definitely often unsatisfactory, because of obvious side effects, ease GRIA3 of relapse and metastasis, and poor prognosis. Therefore, the development of novel methods for HCC treatment is definitely urgently required. In recent years, along with the quick development of biomolecular technology and immunology, tumor biological therapy Lomeguatrib has become a novel and effective restorative tool in comprehensive tumor treatment, and is just about the fourth mode after surgery, chemotherapy, and radiotherapy . A malignancy vaccine provides proactive immunotherapy by inducing anti-tumor immune responses. To day, several HCC vaccine medical trials have been designed based on HCC-specific tumor-associated antigens (TAAs), including alpha fetoprotein (AFP), glypican 3 (GPC3), telomerase reverse transcriptase (TERT), melanoma-associated antigen (MAGE-A), synovial sarcoma, X Breakpoint 2 (SSX-2), and New York esophageal squamous cell carcinoma 1 (NY-ESO-1) [3C5]. However, immunizations with only one or several TAAs generally fail to control overall tumor development, instead they create beneficial conditions for the growth of tumor cell clones that lack the antigens present in the vaccine . Recently, whole tumor cells attenuated by different kinds of treatment or mixed with numerous adjuvants have become the mainstream Lomeguatrib tools for software of HCC vaccines . Unlike tumor-derived specific peptides, a whole tumor lysate is applicable to all individuals, regardless of HLA type. Whole-cell vaccination provides multiple known and unfamiliar TAAs to activate CD4+ T helper and CD8+ cytotoxic lymphocytes (CTL) simultaneously via the vast amount of uncharacterized and characterized T cell epitopes, reducing the chance of tumor immune escape. A study involving approximately 1800 patients shown that individuals treated by whole tumor vaccination experienced a significantly higher objective response than individuals immunized with defined tumor antigens . An irradiated autologous whole tumor lysate was used to treat individuals with malignancy [8, 9]. However, phase III tests of whole-cell vaccines often failed to demonstrate medical benefit . One reason is the low effectiveness of antigen uptake and demonstration, as well as the poor immunogenicity of the tumor lysate, which cannot induce a strong anti-tumor immune response. Additional explanations include immune tolerance and immunosuppression within the tumor stromal microenvironment. To conquer these problems, whole-cell tumor vaccines have been revised by overexpressing stimulatory molecules, such as fibroblast activation protein (FAP), granulocyte-macrophage colony-stimulating element (GM-CSF), and CD86, or combined with CpG oligodeoxynucleotides (CpG ODNs), all of which conferred significant antitumor effects [11C13]. Moreover, depletion of regulatory T cells (Tregs) increases the performance of tumor-cell vaccines . Transmission transducer and activator of transcription 3 (STAT3) is definitely constitutively triggered and overexpressed in many main tumors, and is closely associated with tumor proliferation, angiogenesis, and immune escape . Our earlier findings confirmed that obstructing the STAT3 signaling pathway in HCC cells inhibited proliferation and advertised the apoptosis of tumor cells. In the mean time, the level of sensitivity of STAT3-clogged HCC cells to natural killer (NK) cell cytolysis was significantly enhanced. Most importantly, mice inoculated with STAT3-clogged HCC cells could efficiently break tumor-induced immune tolerance, resulting in an effective anti-tumor effect [15, 16]. These results suggested the manifestation of tumor antigens in HCC cells might be revised by obstructing STAT3 signaling, which would enhance the immunogenicity of the HCC cells. Based on these findings, we hypothesized that STAT3-clogged HCC cells could be used like Lomeguatrib a vaccine. To confirm this hypothesis, in the present study, we prepared a whole cell lysate of.