Head and neck squamous cell carcinoma (HNSCC), an aggressive malignancy, is characterized by high morbidity and low survival rates with limited therapeutic options outside of regional surgery, conventional cytotoxic chemotherapy, and irradiation. Increasing studies have supported the synergistic role of the tumor microenvironment (TME) in cancer advancement. The immune system, in particular, plays a key role in surveillance against the initiation, development, and progression of HNSCC. The understanding of how neoplastic cells evolve and evade the immune system whether through self-immunogenicity manipulation, or expression of immunosuppressive mediators, provides the foundation for the development of advanced therapies. Furthermore, the crosstalk between cancer cells and the host immune system have a detrimental effect on the TME promoting angiogenesis, proliferation, and metastasis. This review provides a recent insight into the role of the key inflammatory cells infiltrating the TME, with a focus on reviewing immunological principles related to HNSCC, as cancer immunosurveillance and immune escape, including a brief overview of current immunotherapeutic strategies and ongoing clinical trials.
Head and Neck Neoplasms/therapy* ; Humans ; Immune Evasion ; Squamous Cell Carcinoma of Head and Neck ; Tumor Microenvironment

Since December 2019, the novel coronavirus (severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) has spread to many countries around the world, developing into a global pandemic with increasing numbers of deaths reported worldwide. To data, although some vaccines have been developed, there are no ideal drugs to treat novel coronavirus pneumonia (coronavirus disease 2019 (COVID-19)). By examining the structure of the coronavirus and briefly describing its possible pathogenesis based on recent autopsy reports conducted by various teams worldwide, this review analyzes the possible structural and functional changes of the human body upon infection with SARS-CoV-2. We observed that the most prominent pathological changes in COVID-19 patients are diffuse alveolar damage (DAD) of the lungs and microthrombus formation, resulting in an imbalance of the ventilation/perfusion ratio and respiratory failure. Although direct evidence of viral infection can also be found in other organs and tissues, the viral load is relatively small. The conclusion that the injuries of the extra-pulmonary organs are directly caused by the virus needs further investigation.
COVID-19/physiopathology* ; Human Body ; Humans ; Immune Evasion ; Lung/virology* ; Viral Load

OBJECTIVE: To investigate the mechanisms of anti-apoptosis and immune evasion in drug-resistant leukemia cells mediated by STAT3, further to explore the possible mechanism of leukemia relapse caused by minimal residual. METHODS: Drug-resistance leukemia cell line was established by transfecting pcDNA3.1-STAT3 into K562 cells (K562/STAT3). The expression of STAT3, BAX and NKG2D ligands (MICA and ULBP1) in K562/-cells, K562/STAT3 were detected by Western blot and/or RQ-PCR. Cells apoptosis and the killing effect of NK cells on leukemia cells were detected by flow cytometry. RESULTS: The expression of the total STAT3, STAT3 phosphorylation in K562/STAT3 was significantly increased, and P-gp mRNA expression was increased also significantly (P<0.005). In K562/STAT3 cells, the expression of pro-apoptotic BAX (P=0.005) was significantly lower, and the number of apoptotic cells (P=0.002) induced by adriamycin was significantly decreased as compared with those in K562/- cells. After K562/STAT3 cells were treated by STAT3 inhibitor (SH-4-54), the expression of BAX mRNA (P=0.017) was significantly higher and the number of apoptotic cells (P=0.005) was significantly increased. The MICA and ULBP1 mRNA expression in K562/STAT3 cells was significantly lower than that in K562/- cells, and also for MICA and ULBP1 protein (MICA and ULPB1 mRNA: P<0.0001, MICA protein: P=0.001, ULPB1 protein: P=0.022). After K562/STAT3 cells were treated with STAT3 inhibitor (SH-4-54), the expression of MICA mRNA and protein was increased (mRNA: P=0.001, protein: P=0.002), but ULBP1 mRNA and protein showed no significantly change (mRNA: P=0.137, protein: P=0.1905). The cytotoxicity of NK cells to K562/STAT3 cells was susceptible as compared with K562/- (P=0.002), but the cytotoxicity of K562/STAT3 cells to NK cell could be recovered by STAT3 inhibitor (P=0.006). CONCLUSION STAT3 phosphorylation can inhibits cell apoptosis and promotes cell immune escape. STAT3 inhibitors can promote the apoptosis of leukemia cells and increase their sensitivity to NK cells.
Apoptosis ; Humans ; Immune Evasion ; K562 Cells ; Killer Cells, Natural ; Leukemia ; Pharmaceutical Preparations ; STAT3 Transcription Factor

BACKGROUND: Nanoparticle-mediated photothermal therapy (PTT) has been well studied as a treatment for cancer. However, the therapeutic outcome of PTT is often hindered by the penetration depth of laser light. In the tumor margin beyond the laser penetration limit, tumor recurrence often occurs, bypassing the immune response of the host. Accumulating evidence suggests the prominent role of tumor microenvironment (TME) and its interactions with the immune components contribute to an immunosuppressive milieu during the post-therapy period. Here, we explored the immunosuppressive cascade generated after PTT, which is responsible for tumor recurrence, and identified the potential targets to achieve an effective PTT period. METHODS: Here, we investigated the immunosuppressive cascade generated after PTT in a CT26 tumor bearing mouse. The liposomal system loaded with the indocyanine green (ICG) was utilized for the generation of PTT with high efficiency. Immunological factors such as cytokines and protein expressions post-therapy were investigated through enzyme-linked immunosorbent assay, flow cytometry and western blot analysis. RESULTS: Our results suggested that PTT with ICG-loaded liposomes (Lipo-ICG) was effective for the first 5 days after treatment, resulting in tumor suppression. However, an immunosuppressive and pro-inflammatory environment developed thereafter, causing the recruitment and upregulation of the immune evasion factors of heat shock protein 70, programmed death ligand 1, indoleamine-dioxygenase, interleukin-6, transforming growth factor-β, regulatory T-cells, and myeloid-derived suppressor cells, to develop immunotolerance. CONCLUSION: Collectively, these findings have determined potential therapeutic targets to modulate the TME during PTT and achieve tumor ablation without remission.
Animals ; Blotting, Western ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; HSP70 Heat-Shock Proteins ; Immune Evasion ; Immunologic Factors ; Immunosuppression ; Indocyanine Green ; Interleukin-6 ; Liposomes ; Mice ; Recurrence ; T-Lymphocytes, Regulatory ; Tumor Microenvironment ; Up-Regulation

Immunotherapy has been introduced into cancer treatment methods, but different problems have restricted the efficacy of these protocols in clinical trials such as the presence of various immunomodulatory factors in the tumor microenvironment. Adenosine is an immunosuppressive metabolite produced by the tumor to promote growth, invasion, metastasis, and immune evasion. Many studies about adenosine and its metabolism in cancer have heightened interest in pursuing this treatment approach. It seems that targeting the adenosine pathway in combination with immunotherapy may lead to efficient antitumor response. In this review, we provide information on the roles of both adenosine and CD73 in the immune system and tumor development. We also describe recent studies about combination therapy with both purinergic inhibitors and other immunotherapeutic methods.
Adenosine ; Immune Evasion ; Immune System ; Immunotherapy ; Metabolism ; Neoplasm Metastasis ; Tumor Microenvironment

BACKGROUND: Human leukocyte antigen class I (HLA-I) molecules play important roles in regulating immune responses. Loss or reduction of HLA-I expression has been shown to be associated with prognosis in several cancers. Regulatory T-cells (Tregs) also play critical functions in immune response regulation. Evaluation of HLA-I expression status by the EMR8-5 antibody and its clinical impact in breast cancer have not been well studied, and its relationship with Tregs remains unclear. METHODS: We evaluated HLA-I expression and Treg infiltration by immunohistochemistry in 465 surgically resected breast cancer samples. We examined the correlation between HLA-I expression and Treg infiltration and clinicopathologic characteristics and survival analyses were performed. RESULTS: Total loss of HLA-I expression was found in 84 breast cancer samples (18.1%). Univariate survival analysis revealed that loss of HLA-I expression was significantly associated with worse disease-specific survival (DSS) (p = .029). HLA-I was not an independent prognostic factor in the entire patient group, but it was an adverse independent prognostic factor for DSS in patients with advanced disease (stage II–IV) (p = .031). Treg numbers were significantly higher in the intratumoral stroma of HLA-I–positive tumors than in HLA-I–negative tumors (median 6.3 cells/high power field vs 2.1 cells/high power field, p < .001). However, Tregs were not an independent prognostic factor in our cohort. CONCLUSIONS: Our findings suggest that the loss of HLA-I expression is associated with poor prognosis in breast cancer patients, highlighting the role of HLA-I alterations in immune evasion mechanisms of breast cancer. HLA-I could be a promising marker that enables the application of more effective and precise immunotherapies for patients with advanced breast cancer.
Breast Neoplasms ; Breast ; Cohort Studies ; HLA Antigens ; Humans ; Immune Evasion ; Immunohistochemistry ; Immunotherapy ; Leukocytes ; Lymphocytes, Tumor-Infiltrating ; Major Histocompatibility Complex ; Prognosis ; T-Lymphocytes, Regulatory

Neisseria gonorrhoeae (NG), as a pathogen of gonorrhea, is strictly limited to growth on the human host. In case of gonococcal infection, the body may recruit such inflammatory cells as neutrophils to resist the invasion of NG or initiate its adaptive immune response by antigen presentation to eliminate the pathogen. However, a series of immune escape mechanisms of NG make it difficult to clear up the infection. In the innate immune system, NG can not only secrete thermonuclease to degrade neutrophile granulocytes, inhibit respiratory burst to resist killing by neutrophils, activate NLRP3 to prompt the pyronecrosis of inflammatory cells, but also regulate the differentiation of macrophages to reduce the inflammatory response, combine with factor H to evade complement-mediated killing. NG infection can hardly give rise to effective adaptive immune response and immune memory, but can promote TGF-β production to inhibit Th1/Th2-mediated adaptive immune response, bind to CEACAM1 on the B cell surface to promote apoptosis in B cells, and combine with CEACAM1 on the T cell surface to inhibit helper T cell proliferation, which makes it difficult for B cells to produce high-affinity specific antibodies. With the increasing drug-resistance of NG, immunological studies may play a significant role in the development of novel therapies and effective vaccines against the infection.
Adaptive Immunity ; Antibodies ; immunology ; Antigens, CD ; immunology ; Cell Adhesion Molecules ; immunology ; Complement Factor H ; immunology ; Gonorrhea ; immunology ; Humans ; Immune Evasion ; immunology ; Immunity, Innate ; immunology ; Neisseria gonorrhoeae ; immunology

PURPOSE: Immune suppression is common in patients with advanced breast cancer but the mechanisms underlying this phenomenon have not been sufficiently studied. In this study, we aimed to identify B7 family members that were able to predict the immune status of patients, and which may serve as potential targets for the treatment of breast cancer. We also aimed to identify microRNAs that may regulate the expression of B7 family members. METHODS: The Cancer Genome Atlas data from 1,092 patients with breast cancer, including gene expression, microRNA expression and survival data, were used for statistical and survival analyses. Polymerase chain reaction and Western blot were used to measure messenger RNA and protein expression, respectively. Luciferase assay was used to investigate direct microRNA target. RESULTS: Bioinformatic analysis predicted that microRNA (miR)-93, miR-195, miR-497, and miR-340 are potential regulators of the immune evasion of breast cancer cells, and that they exert this function by targeting CD274, PDCD1LG2, and NCR3LG1. We chose CD274 for further investigations. We found that miR-195, miR-497, and CD274 expression levels were inversely correlated in MDA-MB-231 cells, and miR-195 and miR-497 expressions mimic inhibited CD274 expression in vitro. Mechanistic investigations demonstrated that miR-195 and miR-497 directly target CD274 3′ untranslated region. CONCLUSION: Our data indicated that the level of B7 family members can predict the prognosis of breast cancer patients, and miR-195/miR-497 regulate CD274 expression in triple negative breast cancer. This regulation may further influence tumor progression and the immune tolerance mechanism in breast cancer and may be able to predict the effect of immunotherapy on patients.
Antigens, CD274 ; B7 Antigens ; Blotting, Western ; Breast Neoplasms ; Computational Biology ; Gene Expression ; Genome ; Humans ; Immune Evasion ; Immune Tolerance ; Immunotherapy ; In Vitro Techniques ; Ligands* ; Luciferases ; MicroRNAs ; Polymerase Chain Reaction ; Prognosis ; RNA, Messenger ; Triple Negative Breast Neoplasms* ; Untranslated Regions

Cancer immunoediting consists of three sequential phases: elimination, equilibrium, and escape. For colorectal adenoma-carcinoma sequence, the adenoma dysplastic progression may represent an equilibrium phase and the cancer stage as escape phase. Immune system eliminates transformed enterocytes by destroying them at first, sculpts them at the same time and selects the variants subsequently that are no longer recognized and insensitive to immune effectors, and finally induces immunosuppressive state within the tumor microenvironment that facilitates immune escape and tumor outgrowth. Immunosuppression and inflammation are the two crucial features of Pi (Spleen)-deficiency. Classic quotations, immune evidence and clinical observations suggest that Spleen (but not other organs) deficiency is the key pathogenesis of colorectal cancer (CRC) microenvironment. Weakness of old age, immunosuppressive cytokines from chronic inflammation, tumor-derived immunosuppressive factors and surrendered immune cells-regulatory T cells, myeloid-derived suppressor cells and tumor associated macrophages (TAMs) constitutes CRC microenvironment of Pi-deficiency. Furthermore, excess in superficiality, such as phlegm stagnation, blood stasis and toxin accumulation are induced by chronic inflammation on the basis of asthenia in origin, an immunosuppressive state. Great masters of Chinese medicine emphasize that strengthen Pi is the chief therapeutic principle for CRC which receives good therapeutic effects. So, Pi-deficiency based syndrome is the pivotal pathogenesis of tumor microenvironment. The immunosuppressive microenvironment facilitates immune escape which play an important role in the transition from adenoma to adenocarcinoma. There are some signs that strengthen Pi based treatment has potential capacity to ameliorate tumor environment. It might be a novel starting point to explore the mechanism of strengthen Pi based therapy in the prevention and treatment of CRC through regulation of tumor environment and immunoediting.
Colorectal Neoplasms ; immunology ; Humans ; Immune Evasion ; Immunosuppression ; Spleen ; immunology ; Syndrome ; Tumor Microenvironment ; immunology

The discovery and understanding of antigenic proteins are essential for development of a vaccine against malaria. In Plasmodium falciparum, Pf92 have been characterized as a merozoite surface protein, and this protein is expressed at the late schizont stage, but no study of Pv92, the orthologue of Pf92 in P. vivax, has been reported. Thus, the protein structure of Pv92 was analyzed, and the gene sequence was aligned with that of other Plasmodium spp. using bioinformatics tools. The recombinant Pv92 protein was expressed and purified using bacterial expression system and used for immunization of mice to gain the polyclonal antibody and for evaluation of antigenicity by protein array. Also, the antibody against Pv92 was used for subcellular analysis by immunofluorescence assay. The Pv92 protein has a signal peptide and a sexual stage s48/45 domain, and the cysteine residues at the N-terminal of Pv92 were completely conserved. The N-terminal of Pv92 was successfully expressed as soluble form using a bacterial expression system. The antibody raised against Pv92 recognized the parasites and completely merged with PvMSP1-19, indicating that Pv92 was localized on the merozoite surface. Evaluation of the human humoral immune response to Pv92 indicated moderate antigenicity, with 65% sensitivity and 95% specificity by protein array. Taken together, the merozoite surface localization and antigenicity of Pv92 implicate that it might be involved in attachment and invasion of a merozoite to a new host cell or immune evasion during invasion process.
Animals ; Computational Biology ; Cysteine ; Fluorescent Antibody Technique ; Humans ; Immune Evasion ; Immunity, Humoral ; Immunization ; Malaria ; Merozoites* ; Mice ; Parasites ; Plasmodium falciparum ; Plasmodium vivax* ; Plasmodium* ; Protein Array Analysis ; Protein Sorting Signals ; Schizonts ; Sensitivity and Specificity