Liqun Tu

All Publications

• Establishment of a prediction model of postoperative infection complications in patients with gastric cancer and its impact on prognosis. Journal of gastrointestinal oncology Dong, Z., Liu, G., Tu, L., Su, X., Yu, Y. 2023; 14 (3): 1250-1258

  Abstract

  Postoperative infection delays postoperative adjuvant therapy and can lead to poor prognosis in gastric cancer patients. Therefore, accurately identifying patients at high risk of postoperative infection in patients with gastric cancer is critical. We therefore conducted a study to analyze the impact of postoperative infection complications on long-term prognosis.From January 2014 to December 2017, we retrospectively collected the data of 571 patients with gastric cancer admitted to the Affiliated People's Hospital of Ningbo University. The patients were divided into an infection group (n=81) and control group (n=490) according to whether the patients experienced postoperative infection. The clinical characteristics of the 2 groups were compared, and the risk factors of postoperative infection complications in patients with gastric cancer were analyzed. Finally, the prediction model of postoperative infection complications was established.There were significant differences in age, diabetes, preoperative anemia, preoperative albumin, preoperative gastrointestinal obstruction, and surgical methods between the 2 groups (P<0.05). Compared with that in the control group, the mortality rate of patients in the infection group at 5 years after surgery was significantly increased (39.51% vs. 26.12%; P=0.013). Multivariate logistics regression analysis showed that age >65 years, preoperative anemia, albumin <30 g/L, and gastrointestinal obstruction were risk factors of postoperative infection in patients with gastric cancer (P<0.05). The data set was randomly divided into a training set and validation set; the sample size of the training set was 286 while the sample size of the validation set was 285. In terms of the predictive model's value in predicting postoperative infection in patients with gastric cancer, the area under the curve of the receiver operating characteristic (ROC) curve in the training set was 0.788 (95% confidence interval: 0.711-0.864), and the area under the curve of the ROC curve in the validation set was 0.779 (95% confidence interval: 0.703-0.855). In the validation set, the model was evaluated with the Hosmer-Lemeshow goodness-of-fit test, resulting in a chi-squared value of 5.589 and a P value of 0.693.The present model can effectively identify patient as high risk of postoperative infection.

  View details for DOI 10.21037/jgo-23-231

  View details for PubMedID 37435220

  View details for PubMedCentralID PMC10331766

• Incorporation of a TGF-β2-inhibiting oligodeoxynucleotide molecular adjuvant into a tumor cell lysate vaccine to enhance antiglioma immunity in mice. Frontiers in immunology Tu, L., Wang, Z., Yang, L., Sun, X., Yao, Y., Zhang, P., Zhang, X., Wang, L., Yu, Y., Yang, M. 2023; 14: 1013342

  Abstract

  Transforming growth factor β2 (TGF-β2), also known as glioma-derived T-cell suppressor factor, is associated with the impairment of tumor immune surveillance. Therefore, blocking TGF-β2 signaling probably be a feasible strategy to develop a novel type of adjuvant for glioma vaccines to enhance antitumor immunity.A TGF-β2 inhibitory oligodeoxynucleotide, TIO3, was designed with sequences complementary to the 3' untranslated region of TGF-β2 mRNA. The expression of TGF-β2 and MHC-I was detected by qPCR, western and flow cytometry in vitro. All the percentage and activation of immune cells were detected by flow cytometry. Subsequently, TIO3 was formulated with Glioma cell lysate (TCL) and investigated for its antitumor effects in GL261 murine glioma prophylactic and therapeutic models.TIO3 could efficiently downregulate the expression of TGF-β2 while increase the MHC-I's expression in GL261 and U251 glioma cells in vitro. Meanwhile, TIO3 was detected in mice CD4+ T, CD8+ T, B and Ly6G+ cells from lymph nodes after 24 hours incubation. Moreover, TCL+TIO3 vaccination significantly prolonged the survival of primary glioma-bearing mice and protected these mice from glioma re-challenge in vivo. Mechanistically, TCL+TIO3 formulation strongly evoke the antitumor immune responses. 1) TCL+TIO3 significantly increased the composition of CD4+ and CD8+ T cells from draining lymph nodes while promoted their IFN-γ production and reduced the expression of TGF-β2 and PD1. 2) TCL+TIO3 activated the NK cells with the elevation of CD69 or NKG2D expression and PD1 reduction. 3) TCL+TIO3 increased the glioma-specific lysis CTLs from spleen. 4) TCL+TIO3 downregulated PD-L1 expression in glioma tissues and in Ly6G+ cells among glioma-infiltrating immune cells.TIO3 is a promising adjuvant for enhancing TCL-based vaccines to produce a more vigorous and long-lasting antitumor response by interfering with TGF-β2 expression.

  View details for DOI 10.3389/fimmu.2023.1013342

  View details for PubMedID 36776837

  View details for PubMedCentralID PMC9914600

• Size-dependent activation of CAR-T cells. Science immunology Xiao, Q., Zhang, X., Tu, L., Cao, J., Hinrichs, C. S., Su, X. 2022; 7 (74): eabl3995

  Abstract

  As the targets of chimeric antigen receptor (CAR)-T cells expand to a variety of cancers, autoimmune diseases, viral infections, and fibrosis, there is an increasing demand for identifying new antigens and designing new CARs that can be effectively activated. However, the rational selection of antigens and the design of CARs are limited by a lack of knowledge regarding the molecular mechanism by which CARs are activated by antigens. Here, we present data supporting a "size exclusion" model explaining how antigen signals are transmitted across the plasma membrane to activate the intracellular domains of CARs. In this model, antigen engagement with CAR results in a narrow intermembrane space that physically excludes CD45, a bulky phosphatase, out of the CAR zone, thus favoring CAR phosphorylation by kinases, which further triggers downstream pathways leading to T cell activation. Aligned with this model, increasing the size of CAR extracellular domains diminished CAR-T activation both in vitro and in a mouse lymphoma model; membrane-proximal epitopes activated CAR-Ts better than membrane-distal epitopes. Moreover, increasing the size of CD45 by antibody conjugation enhanced the activation of CARs that recognize membrane-distal epitopes. Consistently, CAR-Ts expressing CD45RABC, the larger isoform, were activated to a higher level than those expressing a smaller isoform CD45RO. Together, our work revealed that CAR-T activation depends on the size difference between the CAR-antigen pair and CD45; the size of CAR, antigen, and CD45 can thus be targets for tuning CAR-T activation.

  View details for DOI 10.1126/sciimmunol.abl3995

  View details for PubMedID 35930653

  View details for PubMedCentralID PMC9678385

• TGF-β2 interfering oligonucleotides used as adjuvants for microbial vaccines. Journal of leukocyte biology Tu, L., Sun, X., Yang, L., Zhang, T., Zhang, X., Li, X., Dong, B., Liu, Y., Yang, M., Wang, L., Yu, Y. 2020; 108 (5): 1673-1692

  Abstract

  The success of using immune checkpoint inhibitors to treat cancers implies that inhibiting an immunosuppressive cytokine, such as TGF-β2, could be a strategy to develop novel adjuvants for microbial vaccines. To develop nucleic acid based TGF-β2 inhibitors, we designed three antisense oligonucleotides, designated as TIO1, TIO2, and TIO3, targeting the conserve regions identical in human and mouse TGF-β2 mRNA 3'-untranslated region. In cultured immune cells, TIO3 and TIO1 significantly reduced the TGF-β2 mRNA expression and protein production. In mice, the TIO3 and TIO1, when formulated in various microbial vaccines, significantly enhanced the antibody response to the vaccines, and the TIO3-adjuvanted influenza virus vaccine induced effective protection against the influenza virus challenge. In the immunized mice, TIO3 formulated in microbial vaccines dramatically reduced surface-bound TGF-β2 expression on CD4+ T cells and CD19+ B cells in the lymph node (LN) cells and spleen cells; up-regulated the expression of CD40, CD80, CD86, and MHC II molecules on CD19+ B cells and CD11c+ dendritic cells; and promoted IFN-γ production in CD4+ T cells and CD8+ T cells in the LN cells. Overall, TIO3 or TIO1 could be used as a novel type of adjuvant for facilitating the microbial vaccines to elicit more vigorous and persistent antibody response by interfering with TGF-β2 expression.

  View details for DOI 10.1002/JLB.5A0420-491R

  View details for PubMedID 32794350

• Diversity of locally produced IFN-α subtypes in human nasopharyngeal epithelial cells and mouse lung tissues during influenza virus infection. Applied microbiology and biotechnology Yang, L., Wang, S., Wang, Y., Zhao, P., Cui, C., Tu, L., Li, X., Yu, Y., Li, H., Wang, L. 2020; 104 (14): 6351-6361

  Abstract

  The excessively expressed interferon-α (IFN-α) might contribute to the uncontrolled inflammatory responses, causing pathological damage during influenza virus infection. However, the correlation of the pathological damage with the expression profile of IFN-α subtypes in the focus of infection with influenza viruses is poorly understood. To investigate this, we detected the IFN-α subtype dominance in human respiratory epithelial cells and mouse lungs, both of which were infected with influenza viruses. It was found that IFN-α1, IFN-α6, IFN-α14, and IFN-α16 were dominantly expressed in respiratory epithelial cells from the patients infected with IAV, whereas IFN-α5, IFN-α8, and IFN-α21 were dominantly expressed in respiratory epithelial cells from the patients infected with less pathogenic IBV and that IFN-α1, IFN-α9, and IFN-α15 were dominantly expressed in lungs of the mice infected with H1N1 IAV, and IFN-α2, IFN-α12, and IFN-α13 were dominantly expressed in lungs of the mice infected with less pathogenic H9N2 IAV. Compared with H9N2 IAV, H1N1 IAV induced higher mortality rates and more obvious body weight loss in the mice. In addition, IAV or H1N1 IAV induced a significantly higher level of CXCL10 mRNA in the human respiratory epithelial cells or the mouse lungs, respectively. In mice, the high level of Cxcl10 mRNA was accompanied by the abundant infiltrated neutrophils and more severe pathological changes in the lungs. Together, the data presented here indicate that the pathogenicity of influenza viruses is correlated with the IFN-α subtypes induced by influenza viruses. KEY POINTS: • Different influenza viruses induce differential inflammation responses. • Various influenza viruses induce diverse expression profiles of IFN-α subtypes. • The locally produced IFN-α subtypes correlated to the differential inflammation. Graphical abstract.

  View details for DOI 10.1007/s00253-020-10676-y

  View details for PubMedID 32472176

  View details for PubMedCentralID 4033792

• Attenuation of interferon regulatory factor 7 activity in local infectious sites of trachea and lung for preventing the development of acute lung injury caused by influenza A virus. Immunology Yang, L., Tu, L., Zhao, P., Wang, Y., Wang, S., Lu, W., Wang, Y., Li, X., Yu, Y., Hua, S., Wang, L. 2019; 157 (1): 37-51

  Abstract

  The excessive activation of interferon regulatory factor 7 (IRF7) promotes the development of acute lung injury (ALI) caused by influenza A virus (IAV). However, the deficiency of IRF7 increases the susceptibility to deadly IAV infection in both humans and mice. To test whether the attenuation rather than the abolishment of IRF7 activity in local infectious sites could alleviate IAV-induced ALI, we established IAV-infected mouse model and trachea/lung-tissue culture systems, and designed two IRF7-interfering oligodeoxynucleotides, IRF7-rODN M1 and IRF7-rODN A1, based on the mouse and human consensus sequences of IRF7-binding sites of Ifna/IFNA genes, respectively. In the model mice, we found a close relationship between the IAV-induced ALI and the level/activity of IRF7 in local infectious sites, and also found that the reduced IRF7 level or activity in the lungs of mice treated with IRF7-rODN M1 led to decreased mRNA levels of Ifna genes, reduced neutrophil infiltration in the lungs and prolonged survival of mice. Furthermore, we found that the effects of IRF7-rODN M1 on alleviating IAV-induced ALI could be correlated to the reduced translocation of IRF7, caused by the IRF7-rODN M1, from cytosol to nucleus in IAV-infected cells. These data suggest that the proper attenuation of IRF7 activity in local infectious sites could be a novel approach for treating IAV-induced ALI.

  View details for DOI 10.1111/imm.13045

  View details for PubMedID 30667045

  View details for PubMedCentralID PMC6459777

• Anti-glioma effect of intracranial vaccination with tumor cell lysate plus flagellin in mice. Vaccine Dong, B., Wang, L., Nie, S., Li, X., Xiao, Y., Yang, L., Meng, X., Zhao, P., Cui, C., Tu, L., Lu, W., Sun, W., Yu, Y. 2018; 36 (52): 8148-8157

  Abstract

  The adjuvant effects of flagellin on regulation of immune response have been proved; whether flagellin could assist tumor cell lysate (TCL) to enhance anti-glioma immunity remains to be investigated. This study tests a hypothesis that therapeuticly intracranial administration with flagellin plus TCL enhances the effects of specific immunotherapy on glioma in mice. In this study, GL261 cells were transferred into C57BL/6 mice and the GL261-bearing mice were subcutaneously or intracranially inoculated with flagellin plus TCL, flagellin, TCL or saline. Our results showed that prophylacticly subcutaneous administration with TCL and flagellin could induce potent cytotoxic T lymphocyte (CTL) and prolong the survival of GL261-bearing mice significantly, but therapeuticly subcutaneous administration failed to. However, therapeuticly intracranial administration of TCL plus flagellin could prolong the survival. Moreover, intracranial administration of flagellin could recruit CD4+ T cells and CD8+ T cells to brain tissues, induce proliferation of natural killer (NK) cells, CD4+ T cells and CD8+ T cells in peripheral blood mononuclear cells and induce to splenomegaly. The results suggested that flagellin could be acted as an efficient adjuvant for TCL based vaccine.

  View details for DOI 10.1016/j.vaccine.2018.04.053

  View details for PubMedID 30449633

• Virus-like particles of recombinant PCV2b carrying FMDV-VP1 epitopes induce both anti-PCV and anti-FMDV antibody responses. Applied microbiology and biotechnology Li, X., Meng, X., Wang, S., Li, Z., Yang, L., Tu, L., Diao, W., Yu, C., Yu, Y., Yan, C., Wang, L. 2018; 102 (24): 10541-10550

  Abstract

  Mixed infection of porcine circovirus type 2 (PCV2) and foot-and-mouth disease virus (FMDV) is devastating to swine populations. To develop an effective vaccine that can protect the pigs from the infection of PCV2 and FMDV, we used the neutralizing B cell epitope region (aa 135-160) of FMDV to replace the regions aa 123-151 and aa 169-194 of the PCV2b Cap protein to generate a recombinant protein designated as Capfb. The Capfb protein was expressed in Escherichia coli system and the purified Capfb protein assembled into virus-like particles (VLPs) through dialysis. The ability of the Capfb protein to induce effective immune response against FMDV and PCV2b was tested in mice and guinea pigs. The results showed that the Capfb-VLPs could elicit anti-PCV2b and anti-FMDV antibody response in mice and guinea pigs without inducing antibodies against decoy epitope. Moreover, the Capfb-VLPs could enhance the percentage and activation of B cells in lymph nodes when the mice were stimulated with inactivated FMDV or PCV2b. These data suggested that the Capfb-VLPs could be an efficacious candidate antigen for developing a novel PCV2b-FMDV bivalent vaccine.

  View details for DOI 10.1007/s00253-018-9361-2

  View details for PubMedID 30338355

• An AAAG-Rich Oligodeoxynucleotide Rescues Mice from Bacterial Septic Peritonitis by Interfering Interferon Regulatory Factor 5. International journal of molecular sciences Gao, S., Li, X., Nie, S., Yang, L., Tu, L., Dong, B., Zhao, P., Wang, Y., Yu, Y., Wang, L., Hua, S. 2017; 18 (5)

  Abstract

  A previous study found that an AAAG-rich Oligodeoxynucleotide (ODN), designated as MS19, could lessen the acute lung inflammatory injury (ALII) in mice infected by influenza viruses. Bioinformatics analysis found that MS19 is consensus with the binding site of interferon regulatory factor 5 (IRF5) in the regulatory elements of pro-inflammatory genes. This study established a septic peritonitis model in Institute of Cancer Research (ICR) mice infected with Escherichia coli (E. coli), and found that MS19 prolonged the survival of the mice and down-regulated the expression of inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α). In cultured RAW264.7 cells, MS19 significantly reduced the expression of iNOS, IRF5, IL-6, and TNF-α and inhibited the nuclear translocation of IRF5. This data may provide a new insight for understanding how MS19 reduces the excessive inflammatory responses in sepsis.

  View details for DOI 10.3390/ijms18051034

  View details for PubMedID 28492513

  View details for PubMedCentralID PMC5454946

• Adjuvanticity of a CTLA-4 3' UTR complementary oligonucleotide for emulsion formulated recombinant subunit and inactivated vaccines. Vaccine Li, X., Yang, L., Zhao, P., Yao, Y., Lu, F., Tu, L., Liu, J., Li, Z., Yu, Y., Wang, L. 2017; 35 (18): 2379-2389

  Abstract

  Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is recognized as a critical inhibitory regulator of T-cell proliferation and activation, opposing the action of CD28-mediated co-stimulation. Interfering or blocking CTLA-4 can result in continuous T-cell activation required for the full immune response to pathogenic microbes and vaccines. To test if nucleic acid-based CTLA-4 inhibitors could be developed into a novel adjuvant, we designed two oligonucleotides, CMD-1 and CMD-2, with the sequences complementary to the conserve regions identical between human and mouse CTLA-4 mRNA 3' untranslated region (3' UTR), and tested their in vitro effects on CTLA-4 production and their adjuvanticity for vaccines in mice. We found that CMD-1 inhibited the antigen-induced CTLA-4 up-regulation on the CD4+ T cells by interfering its mRNA expression, maintained higher levels of CD80 and CD86 on the CD11c+ cells and promoted the recalled proliferation of the CD4+ T cells and CD19+ B cells, and that the CMD-1 enhanced the antibody response against recombinant PCV2b capsid protein or inactivated foot-and-mouth disease virus in both ICR and BALB/c mice. These data suggest that the CMD-1 could be used as a novel vaccine adjuvant capable of inhibiting inhibitory signals rather than inducing stimulatory signals of immune cells.

  View details for DOI 10.1016/j.vaccine.2017.03.043

  View details for PubMedID 28359618