Dysfunction of sinus macrophages in tumor-bearing host induces resistance to immunotherapy.

Sinus macrophages in draining lymph nodes (DLNs) are involved in anti-tumor immune reactions. CD169 (Sialoadhesin, Siglec-1) is expressed on sinus macrophages and is considered a surrogate marker for the immunostimulatory phenotype of macrophages. In this study, the significance of sinus macrophages in immunotherapy was evaluated using mouse models. Treatment with anti-programmed death-ligand 1 (PD-L1) antibody suppressed the subcutaneous tumor growth of MC38 and E0771 cells but was not effective against MB49 and LLC tumors. Decreased cytotoxic T-lymphocyte (CTL) infiltration in tumor tissues and CD169 expression in sinus macrophages were observed in MB49 and LLC cells compared to corresponding parameters in MC38 and E0771 cells. The anti-tumor effects of the anti-PD-L1 antibody on MC38 and E0771 cells were abolished when sinus macrophages in DLNs were depleted, suggesting that sinus macrophages are involved in the therapeutic effect of the anti-PD-L1 antibody. Naringin activated sinus macrophages. Naringin inhibited tumor growth in MB49- and LLC-bearing mice but did not affect that in MC38- and E0771-bearing mice. The infiltration of CTLs in tumor tissues and their activation were increased by naringin, and this effect was impaired when sinus macrophages were depleted. Combination therapy with naringin and anti-PD-L1 antibody suppressed MB49 tumor growth. In conclusion, CD169-positive sinus macrophages in DLNs are critical for anti-tumor immune responses, and naringin suppresses tumor growth by activating CD169-positive sinus macrophages and anti-tumor CTL responses. The activation status of sinus macrophages has been suggested to differ among tumor models, and this should be investigated in future studies.

Phase I study of a novel therapeutic vaccine as perioperative treatment for patients with surgically resectable hepatocellular carcinoma: The YCP02 trial.

AIM: Developing effective adjuvant therapies is essential for improving the surgical outcomes in patients with hepatocellular carcinoma (HCC). Immunotherapy against HCC has become a promising strategy; however, only approximately 30% of all HCC patients respond to immunotherapy. Previously, we generated the novel therapeutic vaccine comprising multi-human leukocyte antigen-binding heat shock protein 70/glypican-3 peptides with a novel adjuvant combination of hLAG-3Ig and poly-ICLC. We also confirmed the safety of this vaccination therapy, as well as its capacity for the effective induction of immune responses in a previous clinical trial. METHODS: In this phase I study, we administered this vaccine intradermally six times before surgery, and 10 times after surgery to patients with untreated, surgically resectable HCC (stage II to IVa). The primary end-points of this study were the safety and feasibility of this treatment. We also analyzed the resected tumor specimens pathologically using hematoxylin-eosin staining and immunohistochemistry for heat shock protein 70, glypican 3, CD8 and programmed death-1. RESULTS: A total of 20 human leukocyte antigen-matched patients received this vaccination therapy with an acceptable side-effect profile. All patients underwent planned surgery without vaccination-related delay. Immunohistochemical analyses revealed that potent infiltration of CD8+ T cells into tumors with target antigen expression was observed in 12 of 20 (60%) patients. CONCLUSIONS: This novel therapeutic vaccine was safe as perioperative immunotherapy for patients with HCC, and has the potential to strongly induce CD8+ T cells infiltration into tumors.

[Development of CAR-T Cells Effective against Solid Tumors].

Traditionally, the 3 major standard treatments for cancers-surgery, chemotherapy, and radiation therapy-have been applied and have saved many lives. However, malignancies have been the leading cause of death in Japan for more than 40 years since 1981, and the trend is still accelerating. According to the statistics report from the Ministry of Health, Labour and Welfare, cancers accounted for 26.5% of all deaths in 2021, which means that about 1 in 3.5 of all deaths in Japan was due to cancers. Additionally, medical expenditure spent on the diagnosis and treatments for cancer patients have significantly increased, contributing to the pressure on the Japanese economy. Therefore, there is a demand to develop the novel technologies concerning diagnostic methods, effective treatment, and recurrence prevention of cancers. Chimeric antigen receptor(CAR)-T cell therapy has attracted much attention as the next generation of cancer immunotherapy following immune checkpoint blockade therapy, which was the subject of the 2018 Nobel Prize in Physiology or Medicine. CAR-T cell therapy was first approved in the United States in 2017, followed by the EU in 2018 and Japan in March 2019, after having demonstrated significant therapeutic efficacies against B-cell malignancies in clinical trials. However, current CAR-T cell therapies are not yet complete, and there still remain challenges to be overcome. In particular, it is one of the most important issues that current CAR-T cell therapies do not work effectively against solid cancers, which make up the majority of malignant tumors. This review provides an overview of the development toward establishing the next generation CAR-T cell therapy with therapeutic potential against solid cancers.

Paving the road to make chimeric antigen receptor-T-cell therapy effective against solid tumors.

The three major standard therapies, that is, surgery, chemotherapy, and radiation therapy have conventionally been applied to the treatments for cancers and have saved many patients. In addition, for intractable, refractory, or advanced malignancies that cannot be cured by the three standard therapies, immunotherapy is an important subject of basic and clinical researches. Immune checkpoint inhibitor therapy (ICI) has shown significant therapeutic efficacies on some types of tumors in large-scale randomized clinical trials, making a major impact on clinical oncology by scientifically proving and establishing the effectiveness of an immunotherapy. In 2018, ICI was awarded the Nobel Prize in Physiology or Medicine, and immunotherapy is now becoming the "fourth" standard therapy for cancers. Recently, adoptive cell therapies, in which genetically modified T cells with enhanced reactivity against tumors are infused into the patients, have been attracting considerable attention as a hopeful immunotherapy following ICI. Particularly, chimeric antigen receptor (CAR)-T-cell therapies demonstrate marked therapeutic efficacies against some hematologic malignancies, and have been approved in many countries. However, current CAR-T-cell therapy is considered to be little effective against solid tumors, which is one of the challenging issues to be overcome in CAR-T-cell therapy. In this review, we at first introduce CAR and CAR-T cell, and then focus on the recent progress of CAR-T-cell therapy against solid tumors as well as the novel concept on a role of CAR-T cells, aiming to further understandings of the novel cancer immunotherapies.

The expression of PD-1 ligand 1 on macrophages and its clinical impacts and mechanisms in lung adenocarcinoma.

Programmed cell death-1 (PD-1) and PD-1 ligand 1 (PD-L1) are target molecules for immunotherapy in non-small cell lung cancer. PD-L1 is expressed not only in cancer cells, but also on macrophages, and has been suggested to contribute to macrophage-mediated immune suppression. We examined the clinical significance of PD-L1 expression on macrophages in human lung adenocarcinoma. The mechanism of PD-L1 overexpression on macrophages was investigated by means of cell culture studies and animal studies. The results showed that high PD-L1 expression on macrophages was correlated with the presence of EGFR mutation, a lower cancer grade, and a shorter cancer-specific overall survival. In an in vitro study using lung cancer cell lines and human monocyte-derived macrophages, the conditioned medium from cancer cells was found to up-regulate PD-L1 expression on macrophages via STAT3 activation, and a cytokine array revealed that granulocyte-macrophage colony-stimulating factor (GM-CSF) was a candidate factor that induced PD-L1 expression. Culture studies using recombinant GM-CSF, neutralizing antibody, and inhibitors indicated that PD-L1 overexpression was induced via STAT3 activation by GM-CSF derived from cancer cells. In a murine Lewis lung carcinoma model, anti-GM-CSF therapy inhibited cancer development via the suppression of macrophage infiltration and the promotion of lymphocyte infiltration into cancer tissue; however, the PD-L1 expression on macrophages remained unchanged. PD-L1 overexpression on macrophages via the GM-CSF/STAT3 pathway was suggested to promote cancer progression in lung adenocarcinoma. Cancer cell-derived GM-CSF might be a promising target for anti-lung cancer therapy.

PD-L1 on mast cells suppresses effector CD8+ T-cell activation in the skin in murine contact hypersensitivity.

BACKGROUND: The programmed cell death-1 (PD-1)/programmed death ligand 1 (PD-L1) pathway is known to inhibit the activation of effector CD8+ T cells. However, just how this regulatory pathway is involved in the pathophysiology of CD8+ T-cell-mediated inflammatory skin diseases remains unclear. OBJECTIVE: Our aim was to elucidate the mechanisms by which the PD-1/PD-L1 pathway exerts its regulatory roles in CD8+ T-cell-mediated cutaneous immune responses. METHODS: PD-L1-deficient (Pdl1-/-) mice were used for the murine contact hypersensitivity model. Inflammatory responses such as IFN-γ production from CD8+ T cells in the skin was evaluated by flow cytometry. RESULTS: Compared with wild-type mice, Pdl1-/- mice exhibited exacerbated ear swelling and increased numbers of IFN-γ+ CD8+ T cells in the skin. Adoptive T-cell transfer experiments revealed the involvement of the PD-1/PD-L1 pathway in the elicitation phase of contact hypersensitivity. Bone marrow chimera experiments showed that PD-L1 on radioresistant cells was responsible for this regulatory pathway. Flow cytometric analysis revealed that among the radioresistant cells in the skin, PD-L1 was most highly expressed on mast cells (MCs) before and after elicitation. Administration of anti-PD-L1 blocking antibody during the elicitation phase significantly enhanced ear swelling responses and increased the number of IFN-γ+CD8+ T cells in the skin of wild-type mice, whereas no significant effects were observed in MC-deficient (WBB6F1/J-KitW/KitW-v/J and C57BL/6-KitW-sh/W-sh) mice. The high level of expression of PD-L1 on human skin MCs was confirmed by database analysis and immunohistochemical analysis. CONCLUSION: PD-L1 on MCs negatively regulates CD8+ T-cell activation in the skin.

Anti-tumor efficacy of human anti-c-met CAR-T cells against papillary renal cell carcinoma in an orthotopic model.

Chimeric antigen receptor (CAR)-T cell therapy has shown salient efficacy in cancer immunotherapy, particularly in the treatment of B cell malignancies. However, the efficacy of CAR-T for solid tumors remains inadequate. In this study, we displayed that c-met is an appropriate therapeutic target for papillary renal cell carcinoma (PRCC) using clinical samples, developed an anti-human c-met CAR-T cells, and investigated the anti-tumor efficacy of the CAR-T cells using an orthotopic mouse model as pre-clinical research. Administration of the anti-c-met CAR-T cells induced marked infiltration of the CAR-T cells into the tumor tissue and unambiguous suppression of tumor growth. Furthermore, in combination with axitinib, the anti-tumor efficacy of the CAR-T cells was synergistically augmented. Taken together, our current study demonstrated the potential for clinical application of anti-c-met CAR-T cells in the treatment of patients with PRCC.

Enhanced anti-tumor efficacy of IL-7/CCL19-producing human CAR-T cells in orthotopic and patient-derived xenograft tumor models.

Chimeric antigen receptor (CAR)-T cell therapy has impressive efficacy in hematological malignancies, but its application in solid tumors remains a challenge. Multiple hurdles associated with the biological and immunological features of solid tumors currently limit the application of CAR-T cells in the treatment of solid tumors. Using syngeneic mouse models, we recently reported that CAR-T cells engineered to concomitantly produce interleukin (IL)-7 and chemokine (C-C motif) ligand 19 (CCL19)-induced potent anti-tumor efficacy against solid tumors through an improved ability of migration and proliferation even in an immunosuppressive tumor microenvironment. In this study, for a preclinical evaluation preceding clinical application, we further explored the potential of IL-7/CCL19-producing human CAR-T cells using models that mimic the clinical features of solid tumors. Human anti-mesothelin CAR-T cells producing human IL-7/CCL19 achieved complete eradication of orthotopic pre-established malignant mesothelioma and prevented a relapse of tumors with downregulated antigen expression. Moreover, mice with patient-derived xenograft of mesothelin-positive pancreatic cancers exhibited significant inhibition of tumor growth and prolonged survival following treatment with IL-7/CCL19-producing CAR-T cells, compared to treatment with conventional CAR-T cells. Transfer of IL-7/CCL19-producing CAR-T cells resulted in an increase in not only CAR-T cells but also non-CAR-T cells within the tumor tissues and downregulated the expression of exhaustion markers, including PD-1 and TIGIT, on the T cells. Taken together, our current study elucidated the exceptional anti-tumor efficacy of IL-7/CCL19-producing human CAR-T cells and their potential for clinical application in the treatment of patients with solid tumors.

Non-clinical efficacy, safety and stable clinical cell processing of induced pluripotent stem cell-derived anti-glypican-3 chimeric antigen receptor-expressing natural killer/innate lymphoid cells.

The use of allogeneic, pluripotent stem-cell-derived immune cells for cancer immunotherapy has been the subject of recent clinical trials. In Japan, investigator-initiated clinical trials will soon begin for ovarian cancer treatment using human leukocyte antigen (HLA)-homozygous-induced pluripotent stem cell (iPSC)-derived anti-glypican-3 (GPC3) chimeric antigen receptor (CAR)-expressing natural killer/innate lymphoid cells (NK/ILC). Using pluripotent stem cells as the source for allogeneic immune cells facilitates stringent quality control of the final product, in terms of efficacy, safety and producibility. In this paper, we describe our methods for the stable, feeder-free production of CAR-expressing NK/ILC cells from CAR-transduced iPSC with clinically relevant scale and materials. The average number of cells that could be differentiated from 1.8-3.6 × 106 iPSC within 7 weeks was 1.8-4.0 × 109 . These cells showed stable CD45/CD7/CAR expression, effector functions of cytotoxicity and interferon gamma (IFN-γ) production against GPC3-expressing tumor cells. When the CAR-NK/ILC cells were injected into a GPC3-positive, ovarian-tumor-bearing, immunodeficient mouse model, we observed a significant therapeutic effect that prolonged the survival of the animals. When the cells were injected into immunodeficient mice during non-clinical safety tests, no acute systemic toxicity or tumorigenicity of the final product or residual iPSC was observed. In addition, our test results for the CAR-NK/ILC cells generated with clinical manufacturing standards are encouraging, and these methods should accelerate the development of allogeneic pluripotent stem cell-based immune cell cancer therapies.

Anticancer effects of chemokine-directed antigen delivery to a cross-presenting dendritic cell subset with immune checkpoint blockade.

BACKGROUND: Cancer peptide vaccines show only marginal effects against cancers. Immune checkpoint inhibitors (ICIs) show significant curative effects in certain types of cancers, but the response rate is still limited. In this study, we aim to improve cancer peptide vaccination by targeting Ag peptides selectively to a dendritic cell (DC) subset, XCR1-expressing DCs (XCR1+ DCs), with high ability to support CD8+ T-cell responses. METHODS: We have generated a fusion protein, consisting of an Ag peptide presented with MHC class I, and an XCR1 ligand, XCL1, and examined its effects on antitumour immunity in mice. RESULTS: The fusion protein was delivered to XCR1+ DCs in an XCR1-dependent manner. Immunisation with the fusion protein plus an immune adjuvant, polyinosinic:polycytidylic acids (poly(I:C)), more potently induced Ag-specific CD8+ T-cell responses through XCR1 than the Ag peptide plus poly(I:C) or the Ag protein plus poly(I:C). The fusion protein plus poly(I:C) inhibited the tumour growth efficiently in the prophylactic and therapeutic tumour models. Furthermore, the fusion protein plus poly(I:C) showed suppressive effects on tumour growth in synergy with anti-PD-1 Ab. CONCLUSIONS: Cancer Ag targeting to XCR1+ DCs should be a promising procedure as a combination anticancer therapy with immune checkpoint blockade.

A phase I study of multi-HLA-binding peptides derived from heat shock protein 70/glypican-3 and a novel combination adjuvant of hLAG-3Ig and Poly-ICLC for patients with metastatic gastrointestinal cancers: YNP01 trial.

BACKGROUND: This phase I study aimed to evaluate the safety, peptide-specific immune responses, and anti-tumor effects of a novel vaccination therapy comprising multi-HLA-binding heat shock protein (HSP) 70/glypican-3 (GPC3) peptides and a novel adjuvant combination of hLAG-3Ig and Poly-ICLC against metastatic gastrointestinal cancers. METHODS: HSP70/GPC3 peptides with high binding affinities for three HLA types (A*24:02, A*02:01, and A*02:06) were identified with our peptide prediction system. The peptides were intradermally administered with combined adjuvants on a weekly basis. This study was a phase I dose escalation clinical trial, which was carried out in a three patients' cohort; in total, 11 patients were enrolled for the recommended dose. RESULTS: Seventeen patients received this vaccination therapy without dose-limiting toxicity. All treatment-related adverse events were of grades 1 to 2. Peptide-specific CTL induction by HSP70 and GPC3 proteins was observed in 11 (64.7%) and 13 (76.5%) cases, respectively, regardless of the HLA type. Serum tumor marker levels were decreased in 10 cases (58.8%). Immunological analysis using PBMCs indicated that patients receiving dose level 3 presented with significantly reduced T cell immunoglobulin and mucin-domain containing-3 (TIM3)-expressing CD4 + T cells after one course of treatment. PD-1 or TIM3-expressing CD4 + T cells and T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT)-expressing CD8 + T cells in PBMCs before vaccination were negative predictive factors for survival. CONCLUSIONS: This novel peptide vaccination therapy was safe for patients with metastatic gastrointestinal cancers.

Improved survival of chimeric antigen receptor-engineered T (CAR-T) and tumor-specific T cells caused by anti-programmed cell death protein 1 single-chain variable fragment-producing CAR-T cells.

Chimeric antigen receptor-engineered T (CAR-T)-cell therapy holds significant promise for the treatment of hematological malignancies, especially for B-cell leukemia and lymphoma. However, its efficacy against non-hematological malignancies has been limited as a result of several biological problems characteristic of the tumor microenvironment of solid tumors. One of the main hurdles is the heterogeneous nature of tumor-associated antigens (TAA) expressed in solid tumors. Another hurdle is the inefficient activation and limited persistence of CAR-T cells, mainly as a result of T-cell exhaustion caused by immunosuppressive factors in the tumor microenvironment. In the present study, to address these problems, we engineered CAR-T cells to produce antagonistic anti-programmed cell death protein 1 (PD-1) single-chain variable fragment (scFv), by which PD-1-dependent inhibitory signals in CAR-T cells and adjacent tumor-specific non-CAR-T cells are attenuated. In mouse solid tumor models, PD-1 scFv-producing CAR-T cells induced potent therapeutic effects superior to those of conventional CAR-T cells, along with a significant reduction of apoptotic cell death not only in CAR-T cells themselves but also in TAA-specific T cells in the tumor tissue. In addition, the treatment with anti-PD-1 scFv-producing CAR-T cells resulted in an increased concentration of PD-1 scFv in tumor tissue but not in sera, suggesting an induction of less severe systemic immune-related adverse events. Hence, the present study developed anti-PD-1 scFv-producing CAR-T cell technology and explored its cellular mechanisms underlying potent antitumor efficacy.

Inhibitory functions of PD-L1 and PD-L2 in the regulation of anti-tumor immunity in murine tumor microenvironment.

Although a role of PD-L1 in the suppression of anti-tumor immunity and its value as a predictive biomarker has been suggested by various preclinical and clinical studies, the precise mechanisms how PD-L1 and PD-L2, another ligand of PD-1, regulate anti-tumor immunity in the tumor microenvironment are yet to be fully explored. Here, we address this issue using PD-L1-deficient tumor cells, PD-L1-knockout (KO) mice, anti-PD-L1 monoclonal antibody (mAb), and anti-PD-L2 mAb. Firstly, PD-L1-deficient or competent tumor cells were inoculated into wild-type or PD-L1-KO mice. Results of tumor growth and mouse survival indicated that both tumor- and host-derived PD-L1 are functional to suppress anti-tumor immunity, while the former contributes predominantly than the latter. Experiments using bone marrow (BM) chimeric mice, generated by transferring PD-L1-KO BM cells into wild-type mice or vice versa, further suggested that PD-L1 expressed on BM-derived hematopoietic cells mediates the suppressive effects on anti-tumor immunity. Secondly, anti-PD-L2 mAb treatment demonstrated a profound synergy with anti-PD-L1 mAb therapy, whereas anti-PD-L2 mAb alone hardly induced any anti-tumor effects, suggesting that PD-L2's function becomes evident when the effects of PD-L1 are abrogated by anti-PD-L1 mAb. Consistent with this notion, PD-L2 expression was upregulated on tumor-associated macrophages (TAM) when mice were treated with anti-PD-L1 mAb. Taken together, our study elucidated the importance of PD-L1 associated with tumor cells and non-tumor host cells, particularly BM-derived hematopoietic cells, as well as PD-L2 inducibly expressed on TAM in the suppression of anti-tumor immunity in the tumor microenvironment.

Cancer Immunotherapy Targeting Co-signal Molecules.

Great success of immune checkpoint blockade represented by anti-PD-1 monoclonal antibodies (mAbs) has changed a landscape of cancer immunotherapy. There is no doubt about an importance of co-signal molecules as one of the most promising targets in anti-cancer drugs. However, it should be noted that the proportion of patients who have objective and durable responses to immune checkpoint blockade remains less than 30% in majority of cancers. Thus, in addition to refine the usage of existing drugs for checkpoint blockade, identification and characterization of novel checkpoint molecules other than CTLA-4 and PD-1 is a highly anticipated research subject. In addition, agonists of stimulatory co-signal molecules have a potential to further improve anti-tumor effects, rendering them attractive in research and drug development. In this chapter, functions of co-signal molecules in anti-tumor immunity in terms of pre-clinical animal models as well as clinical trials are described.

[Cancer Immunotherapy Using Gene Modification Technology].

Recently, accumulating discoveries in the field of immunology have been applied in clinical settings along with rapid progression of basic and pre-clinical research. Especially, advancement of gene modification technologies has contributed to unlock a way to novel cancer immunotherapy. One representative is chimeric antigen receptor-expressing T(CAR-T)cell therapy which was approved by FDA in August, 2017 as first gene-modified cell therapy. However, such technologies are still work-in-progress and there are many obstacles to be overcome for their full development. So called 4th generation CAR-T cells, in which CAR-T cells are engineered to secrete some kinds of cytokine and/or chemokine, have revealed their prominent potential to eradicate established solid tumors, which are usually resistant to conventional CAR-T cells. Another example of gene-modified cells for cancer immunotherapy is T cell receptor(TCR)-T cells, which are T cells engineered to express tumor antigen-specific TCR. Targeting neoantigens, mutated proteins to be expressed only in cancer cells and scarcely in normal ones, is attracting attempt for TCR-T cell approach. In addition, due to unique immunological functions, other lymphocyte subsets such as natural killer(NK)cells, invariant natural killer T(iNKT)cells, and gd-type T cells gain attention as effector cells to be gene-modified. Furthermore, off-the-shelf cell therapy, in which patients receive cell products made from allogeneic non-self immune cells, is nowunder development. It should be noted that development of "personalized" medicine, which aims to customize drugs to be suitable for each patient and different types of tumor, and "universal" technologies, which are crucial to generate uniform quality of cell products and to decrease manufacturing time and cost, are highly important for further advance of cancer immunotherapy.

Pathogenic Function of Herpesvirus Entry Mediator in Experimental Autoimmune Uveitis by Induction of Th1- and Th17-Type T Cell Responses.

Herpesvirus entry mediator (HVEM), a member of the TNFR superfamily, serves as a unique molecular switch to mediate both stimulatory and inhibitory cosignals, depending on its functions as a receptor or ligand interacting with multiple binding partners. In this study, we explored the cosignaling functions of HVEM in experimental autoimmune uveitis (EAU), a mouse model resembling human autoimmune uveitis conditions such as ocular sarcoidosis and Behcet disease. Our studies revealed that EAU severity significantly decreased in HVEM-knockout mice compared with wild-type mice, suggesting that stimulatory cosignals from the HVEM receptor are predominant in EAU. Further studies elucidated that the HVEM cosignal plays an important role in the induction of both Th1- and Th17-type pathogenic T cells in EAU, including differentiation of IL-17-producing αß(+)γδ(-) conventional CD4(+) T cells. Mice lacking lymphotoxin-like, inducible expression, competes with herpes simplex virus glycoprotein D for HVEM, a receptor expressed by T lymphocytes : LIGHT), B- and T-lymphocyte attenuator (BTLA) or both LIGHT and BTLA are also less susceptible to EAU, indicating that LIGHT-HVEM and BTLA-HVEM interactions, two major molecular pathways mediating HVEM functions, are both important in determining EAU pathogenesis. Finally, blocking HVEM cosignals by antagonistic anti-HVEM Abs ameliorated EAU. Taken together, our studies revealed a novel function of the HVEM cosignaling molecule and its ligands in EAU pathogenesis through the induction of Th1- and Th17-type T cell responses and suggested that HVEM-related molecular pathways can be therapeutic targets in autoimmune uveitis.

[In Vivo Antigen Delivery to Dendritic Cells-A Novel Peptide Vaccine for Cancer Therapy].

Tumor-derived peptides can induce antitumor cytotoxic T lymphocyte(CTL)response. However, the effects are limited. We aimed to overcome this limitation by selectively delivering antigen peptides to an XC chemokine receptor 1-expressing dendritic cell subset(XCR1+DC)that is notable for its exceptional ability to generate CTL response. To do that, we designed a vaccine(mXCL1-OVA peptide vaccine)that consisted of a murine XCR1 ligand(XCL1)and an ovalbumin(OVA)-derived MHC class I-restricted antigen. When co-injected with the immune adjuvant polyinosinic-polycytidylic acid(poly[I: C]), mXCL1-OVA peptide vaccine showed much greater antigen-specific cytotoxic T cell(CTL)response than either OVA protein plus poly(I: C)or OVA peptide plus poly(I: C). Furthermore, mXCL1-OVA peptide vaccine plus poly(I: C)showed more prominent antitumor effects against OVA-expressing melanoma(B16-OVA)than other vaccines with regard to growth inhibition. Thus, our results suggest that chemokine-directed antigen delivery to DC subsets with high CTL-inducing ability is a promising method for generating effective antitumor immunity.

Chimeric antigen receptor (CAR)-T cell therapy.

Chimeric antigen receptor (CAR)-T cell therapy, where patients' own T cells are engi- neered to express receptor that targets antigen found on the surface of cancer cells, delivers outstanding efficacy to treat hematological malignancies. This personalized medicine has been actively explored by researchers in academia and quickly developed for clinical applica- tion by several pharmaceutical/biotech companies. While CAR-T cell therapy is a highly promising technology, many challenges remain to be overcome in targeting solid tumors, in- cluding on-target off-tumor toxicity, inefficient accumulation and survival of CAR-T cells in the immunosuppressive tumor microenvironment. In this review, we briefly describe the cur- rent status, challenges, and future perspectives of CAR-T cell therapy.

Combined adjuvants of poly(I:C) plus LAG-3-Ig improve antitumor effects of tumor-specific T cells, preventing their exhaustion.

Therapeutic cancer vaccines are designed to treat cancer by boosting the endogenous immune system to fight against the cancer. In the development of clinically effective cancer vaccines, one of the most practical objectives is to identify adjuvants that are capable of optimizing the vaccine effects. In this study, we explored the potential of polyinosinic-polycytidylic acid (poly(I:C)) and LAG-3-Ig (soluble recombinant protein of lymphocyte activation gene-3 [LAG-3] extracellular domain fused with human IgG Fc region) as adjuvants for P1A tumor antigen peptide vaccine in a pre-established P815 mouse tumor model with a transfer of tumor-specific T cells. Whereas the use of poly(I:C) or LAG-3-Ig as a signal adjuvant induced a slight enhancement of P1A vaccine effects compared to incomplete Freund's adjuvant, combined treatment with poly(I:C) plus LAG-3-Ig remarkably potentiated antitumor effects, leading to complete rejection of pre-established tumor and long-term survival of mice. The potent adjuvant effects of poly(I:C) plus LAG-3-Ig were associated with an enhanced infiltration of T cells in the tumor tissues, and an increased proliferation and Th1-type cytokine production of tumor-reactive T cells. Importantly, the combined adjuvant of poly(I:C) plus LAG-3-Ig downregulated expressions of PD-1, LAG-3, and TIGIT on P1A-specific T cells, indicating prevention of T cell exhaustion. Taken together, the results of the current study show that the combined adjuvants of poly(I:C) plus LAG-3-Ig with tumor peptide vaccine induce profound antitumor effects by activating tumor-specific T cells.

Tumor necrosis factor superfamily 14 (LIGHT) controls thymic stromal lymphopoietin to drive pulmonary fibrosis.

BACKGROUND: Pulmonary fibrosis is characterized by excessive accumulation of collagen and α-smooth muscle actin in the lung. The key molecules that promote these phenotypes are of clinical interest. OBJECTIVES: Thymic stromal lymphopoietin (TSLP) has been found at high levels in patients with asthma and idiopathic pulmonary fibrosis, and TSLP has been proposed as a primary driver of lung fibrotic disease. We asked whether tumor necrosis factor superfamily protein 14 (TNFSF14) (aka LIGHT) controls TSLP production to initiate fibrosis. METHODS: Expression of TSLP and initiation of pulmonary fibrosis induced by bleomycin were assessed in mice deficient in LIGHT. The ability of recombinant LIGHT, given intratracheally to naive mice, to promote TSLP and fibrosis was also determined. RESULTS: Genetic deletion of LIGHT abolished lung TSLP expression driven by bleomycin, accompanied by near-complete absence of accumulation of lung collagen and α-smooth muscle actin. Furthermore, recombinant LIGHT administered in vivo induced lung expression of TSLP in the absence of other inflammatory stimuli, and strikingly reproduced the primary features of bleomycin-driven disease in a TSLP-dependent manner. Blockade of LIGHT binding to either of its receptors, herpes virus entry mediator and lymphotoxin beta receptor, inhibited clinical symptoms of pulmonary fibrosis, and correspondingly both receptors were found on human bronchial epithelial cells, a primary source of TSLP. Moreover, LIGHT induced TSLP directly in human bronchial epithelial cells and synergized with IL-13 and TGF-ß in vivo to promote TSLP in the lungs and drive fibrosis. CONCLUSIONS: These results show that LIGHT is a profibrogenic cytokine that may be a key driver of TSLP production during the initiation and development of lung fibrotic disease.