Classification of PD-L1 expression in various cancers and macrophages based on immunohistocytological analysis

IL-32 production from lung adenocarcinoma cells is potentially involved in immunosuppressive microenvironment

Interleukin 32 (IL-32) is a proinflammatory cytokine secreted from several kinds of cancer cells. In the present study, we investigated the significance of IL-32 in lung adenocarcinoma by immunohistochemistry and bioinformatics analysis. IL-32 was positive in cancer cells of 21 cases (9.2%) of total 228 cases. Increased IL-32 gene expression was linked to worse clinical course in TCGA analysis, however, IL-32 expression in immunohistochemistry was not associated to clinical course in our cohort. It was also found that high IL-32 expression was seen in cases with increased lymphocyte infiltration. In vitro studies indicated that IFN-γ induced gene expression of IL-32 and PD1-ligands in lung adenocarcinoma cell lines. IL-32, especially IL-32β, also induced overexpression of PD1-ligands in human monocyte-derived macrophages. Additionally, Cancer-cell-derived IL-32 was elevated by stimulation with anticancer agents. In conclusion, IL-32 potentially induced by inflammatory conditions and anticancer therapy and contribute to immune escape of cancer cells via development the immunosuppressive microenvironment. IL-32 might be a target molecule for anti-cancer therapy.

Integrated analyses of the genetic and clinicopathological features of cholangiolocarcinoma: cholangiolocarcinoma may be characterized by mismatch-repair deficiency

Cholangiolocarcinoma (CLC) is a primary liver carcinoma that resembles the canals of Hering and that has been reported to be associated with stem cell features. Due to its rarity, the nature of CLC remains unclear, and its pathological classification remains controversial. To clarify the positioning of CLC in primary liver cancers and identify characteristics that could distinguish CLC from other liver cancers, we performed integrated analyses using whole-exome sequencing (WES), immunohistochemistry, and a retrospective review of clinical information on eight CLC cases and two cases of recurrent CLC. WES demonstrated that CLC includes IDH1 and BAP1 mutations, which are characteristic of intrahepatic cholangiocarcinoma (iCCA). A mutational signature analysis showed a pattern similar to that of iCCA, which was different from that of hepatocellular carcinoma (HCC). CLC cells, including CK7, CK19, and EpCAM, were positive for cholangiocytic differentiation markers. However, the hepatocytic differentiation marker AFP and stem cell marker SALL4 were completely negative. The immunostaining patterns of CLC with CD56 and epithelial membrane antigen were similar to those of the noncancerous bile ductules. In contrast, mutational signature cluster analyses revealed that CLC formed a cluster associated with mismatch-repair deficiency (dMMR), which was separate from iCCA. Therefore, to evaluate MMR status, we performed immunostaining of four MMR proteins (PMS2, MSH6, MLH1, and MSH2) and detected dMMR in almost all CLCs. In conclusion, CLC had highly similar characteristics to iCCA but not to HCC. CLC can be categorized as a subtype of iCCA. In contrast, CLC has characteristics of dMMR tumors that are not found in iCCA, suggesting that it should be treated distinctly from iCCA. © 2024 The Pathological Society of Great Britain and Ireland.

Pathogenicity of functionally activated PD-1+CD8+ cells and counterattacks by muscular PD-L1 through IFNγ in myositis

Programmed-cell-death 1 (PD-1) expression is associated not only with T-cell activation but with exhaustion. Specifically, PD-1+ T cells present an exhausted phenotype in conditions of chronic antigen exposure, such as tumor microenvironments and chronic viral infection. However, the immune status regarding exhaustion of PD-1+CD8+ T cells in chronic autoimmune diseases including idiopathic inflammatory myopathies (IIMs) remains unclear. We aimed to clarify the role of PD-1+CD8+ T cells and PD-1 ligand (PD-L1) in IIMs. We showed that PD-1+ cells infiltrated into PD-L1-expressing muscles in patients with IIMs and immune checkpoint inhibitor-related myopathy. According to the peripheral blood immunophenotyping, the PD-1+CD8+ cell proportions were comparable between the active and inactive patients. Of note, PD-1+CD8+ cells in the active patients highly expressed cytolytic molecules, indicating their activation, while PD-1-CD8+ cells expressed low levels of cytolytic molecules in the active and inactive patients. A part of PD-1+CD8+ cells expressed the HMG-box transcription factor TOX highly and presented the exhausted phenotype in the active patients. Among PD-1+CD4+ T cells, PD-1highCXCR5-CD45RO+CD4+ peripheral helper T cells were increased in the active patients. PD-L1-deficient mice developed severer C-protein-induced myositis (CIM), a model of polymyositis, with abundant infiltration of PD-1+CD8+ cells expressing cytolytic molecules than wild-type mice, indicating pathogenicity of the PD-1+CD8+ cells and the protective role of PD-L1. The deficiency of IFNγ, a general PD-L1-inducer, impaired muscular PD-L1 expression and exacerbated CIM, indicating IFNγ-dependent muscular PD-L1 regulation. IFNγ-induced PD-L1 on myotubes was protective in an established muscle injury model. In conclusion, PD-1+CD8+ T cells rather than PD-1-CD8+ T cells were a pathogenic subset of IIMs. Muscular PD-L1 was regulated by IFNγ and exerted protective properties in IIMs.

The relationship between tumor infiltrating immune cells and the prognosis of patients with lung adenocarcinoma

Background

To depict the immune infiltration characteristics of tumor cells in patients with lung adenocarcinoma (LUAD) and evaluate the predictive value and significance of tumor immune cells on the prognosis of LUAD patients.

Methods

The clinical characteristics and transcriptome of LUAD patients were obtained from The Cancer Genome Atlas (TCGA), and the immune cell abundance in LUAD tissue was evaluated using the CIBERSORT algorithm. We created a simplified immune cell-based Cox regression model according to the survival status of patients and clarified the correlation between the survival status of patients and seven types of immune cells. An immune cell-based risk prediction model was created by Cox proportional hazards regression. Subsequently, the gene expression profile of LUAD patients was obtained from the Gene Expression Omnibus (GEO) database to validate the tumor immune infiltration and patient prognosis prediction model attained using the CIBERSORT algorithm.

Results

The abundance of 22 tumor-infiltrating immune cells in these patients was detected using the CIBERSORT algorithm. According to Pearson correlation analysis, the immune cells appeared to be closely related to each other. The immune cell composition was remarkably different between the LUAD tumor tissue and paracancerous tissue. The simplified COX model showed that seven kinds of immune cells have predictive value for the prognosis and survival status of LUAD. The receiver operating characteristic curve (ROC) curve confirmed that the prediction model performed well for 1-, 3-, and 5-year survival status. The calibration curve suggested that the prediction model was consistent with the clinical results. Correlation analysis revealed that the clinical features were significantly related to immune cell infiltration. A total of 246 LUAD specimens were from the GEO database, and the risk score model suggested that high risk scores were indicative of a poor prognosis. Finally, enzyme-linked immunosorbent assay (ELISA) revealed that the expressions of tumor necrosis factor-α (TNF-α), interleukin 8 (IL-8), IL-6, and interferon-γ (IFN-γ) in tumor tissues were remarkably higher compared with those in adjacent tissues.

Conclusions

There is a close correlation between the tumor-infiltrating immune cells and the prognosis and clinical characteristics of LUAD patients. The risk score model based on TCGA and GEO designed in this study can be applied in clinical practice.

Prospective role of PD-1/PD-L1 immune checkpoint inhibitors in GI cancer

One of the mechanisms by which tumor cells can evade the immune system is over activation of the programmed cell death protein-1 (PD-1) / programmed death-ligand 1 (PD-L1) pathway. The binding of PD-1 to its ligand PD-L1 can trigger an inhibitory signal for reducing T-cell proliferation, inhibiting the anticancer effect of T cells, and limiting the anti-tumor immunity of effectors T cell responses to protect tissues from immune-mediated tissue damage in the tumor microenvironment (TME). PD-1/PD-L1 immune checkpoint inhibitors have created a new pattern in cancer immunotherapy and can increase T cell- surveillance; therefore, the development of better clinical application of PD-1/PD-L1 inhibitors can significantly enhance antitumor immunity and prolong survival in GI cancer patients.

The role of PD-1/PD-L1 and application of immune-checkpoint inhibitors in human cancers

Programmed cell death protein-1 (PD-1) is a checkpoint receptor expressed on the surface of various immune cells. PD-L1, the natural receptor for PD-1, is mainly expressed in tumor cells. Studies have indicated that PD-1 and PD-L1 are closely associated with the progression of human cancers and are promising biomarkers for cancer therapy. Moreover, the interaction of PD-1 and PD-L1 is one of the important mechanism by which human tumors generate immune escape. This article provides a review on the role of PD-L1/PD-1, mechanisms of immune response and resistance, as well as immune-related adverse events in the treatment of anti-PD-1/PD-L1 immunotherapy in human cancers. Moreover, we summarized a large number of clinical trials to successfully reveal that PD-1/PD-L1 Immune-checkpoint inhibitors have manifested promising therapeutic effects, which have been evaluated from different perspectives, including overall survival, objective effective rate and medium progression-free survival. Finally, we pointed out the current problems faced by PD-1/PD-L1 Immune-checkpoint inhibitors and its future prospects. Although PD-1/PD-L1 immune checkpoint inhibitors have been widely used in the treatment of human cancers, tough challenges still remain. Combination therapy and predictive models based on integrated biomarker determination theory may be the future directions for the application of PD-1/PD-L1 Immune-checkpoint inhibitors in treating human cancers.