Browsing by Subject "T cells"

Now showing 1 - 7 of 7
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    Enhanced autophagy and phagocytosis of apoptotic lymphocytes in splenic macrophages of acute ethanol-treated rats: Light and electron microscopic studies
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Betsuyaku, Tsubasa; Ito, Yuko; Peake, Nicholas; Al Bari, Abdul Alim; El Akabawy, Gehan; Eid, Nabil
    Autophagy is a prosurvival mechanism for the clearance of damaged cellular components, specifically upon exposure to various stressors. In lymphoid organs, excessive ethanol consumption increases lymphocyte apoptosis, resulting in immunosuppression. However, ethanol-induced autophagy and related phagocytosis of apoptotic lymphocytes in the spleen have not been studied yet. Adult male Wistar rats were injected intraperitoneally either with 5 g/kg ethanol or phosphate-buffered saline (as a control group) and then sacrificed 0, 3, 6, and 24 hours after injection. Light and transmission electron microscopy (TEM) findings indicated enhanced T cell apoptosis in the white pulps of ethanol-treated rats (ETRs) compared with the control group, which peaked at 6h and was associated with the accumulation of tingible body macrophages (TBMs). These macrophages exhibited an upregulated autophagic response, as evidenced by enhanced LC3-II (a specific marker of autophagosomes) expression, which peaked at 24h. In addition, double labeling immunofluorescence of LC3-II with lysosomal markers revealed the enhanced formation of autolysosomes in TBMs of ETRs, which was associated with suppression of p62 immunostaining, indicating the enhanced autophagic flux. Interestingly, this elevated autophagic response in ETR TBMs was accompanied by evidence of LC3-associated phagocytosis (LAP) of apoptotic splenocytes. This is based on TUNEL/LC3-II double labeling and TEM observations of phagosomes containing apoptotic bodies, enclosed within phagosomal membranes adjacent to the autophagic vacuoles. It can be concluded that enhanced prosurvival autophagy in splenic TBMs of ETRs and clearing of apoptotic lymphocytes via LAP may contribute to preventing secondary necrosis and autoimmune diseases.
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    Glioblastoma progression is assisted by induction of immunosuppressive function of pericytes through interaction with tumor cells
    (Impact Journals, 2017-08-02) Valdor, Rut; García Bernal, David; Bueno, Carlos; Ródenas, Mónica; Moraleda, José M.; Macián, Fernando; Martínez, Salvador; Bioquímica y Biología Molecular B e Inmunología
    The establishment of immune tolerance during Glioblastoma Multiforme (GBM) progression, is characterized by high levels expression of anti-inflammatory cytokines, which suppress the function of tumor assocciated myeloid cells, and the activation and expansion of tumor antigen specific T cells. However, the mechanisms underlying the failed anti-tumor immune response around the blood vessels during GBM, are poorly understood. The consequences of possible interactions between cancer cells and the perivascular compartment might affect the tumor growth. In this work we show for the first time that GBM cells induce immunomodulatory changes in pericytes in a cell interaction-dependent manner, acquiring an immunosuppresive function that possibly assists the evasion of the anti-tumor immune response and consequently participates in tumor growth promotion. Expression of high levels of anti-inflammatory cytokines was detected in vitro and in vivo in brain pericytes that interacted with GBM cells (GBC-PC). Furthermore, reduction of surface expression of co-stimulatory molecules and major histocompatibility complex molecules in GBC-PC correlated with a failure of antigen presentation to T cells and the acquisition of the ability to supress T cell responses. In vivo, orthotopic xenotransplant of human glioblastoma in an immunocompetent mouse model showed significant GBM cell proliferation and tumor growth after the establishment of interspecific immunotolerance that followed GMB interaction with pericytes.
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    Immune based therapies in cancer
    (Murcia : F. Hernández, 2007) Krüger, C.; Greten, T.F.; Korangy, F.
    Immunotherapy of cancer has become a more promising approach in the past decade. Developments in both basic immunology and tumor biology have increased our knowledge of the interactions between the tumor cells and the immune system. The molecular identification of tumor-associated antigens and understanding of immunological pathways have cleared the way for development of different strategies for anti-tumor vaccines. The success of any cancer vaccine relies on the induction of an effective tumor-specific immune response to break tolerance and to elicit a long lasting anti-tumor immunity. It is also increasingly clear that the interactions of host-tumor are quite complicated leading to tumor escape mechanisms, which add another level of difficulty to this interaction. This review will summarize the recent developments in tumor immunotherapy as well as the clinical trials addressing novel immunotherapeutic approaches to cancer.
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    Inhibition of dendritic cell autophagy alleviates the progression of allergic rhinitis by inhibiting Th1/Th2/Th17 immune imbalance and inflammation
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Xiao, Changwu; Feng, Lizhi; Yang, Wei
    Introduction. Immune imbalance is a fundamental immunological feature of allergic rhinitis (AR). The autophagy in CD11c+ dendritic cells (DCs), the strongest antigen-presenting cells, was reported to induce the occurrence of AR by facilitating CD4+ T cell immune imbalance and subsequent inflammation. Our study was designed to confirm that inhibition of DC autophagy can alleviate the progression of AR by inhibiting the T cell immune imbalance. Methods. The AR mouse model was established by using ovalbumin (OVA). OVA-induced mouse models were then injected intraperitoneally with the autophagy inhibitor Baf-A1. Levels of OVA-specific IgE, PGD2, ECP, LTC4, and Th1/Th2/Th17 cell-related cytokines in serum or nasal lavage fluid (NLF) were examined using the corresponding commercial ELISA kits. Morphological changes in the nasal mucosa were observed by HE staining. Nasal mucosa tissues were collected for western blotting to assess the expression of autophagy markers (LC3, P62, and Beclin 1) in each group of mice. Results. Baf-A1 treatment alleviated the allergic symptoms, mitigated inflammatory immune cell infiltration in the nasal mucosa, decreased IgE, LTC4, ECP, and PGD2 levels in both serum and NLF, impaired CD11c+ DC autophagy, and restored Th1/Th2/Th17 cytokine imbalance in OVA-induced AR mice. Furthermore, Baf-A1 treatment also reversed the immune imbalance of CD4+ T cell subtypes and attenuated Th1/Th2/Th17 cytokine imbalance in vitro. Conclusion. Inhibition of CD11c+ DC autophagy suppressed the immune imbalance of CD4+ T cell subsets and attenuated the subsequent inflammatory response, thereby ameliorating the progression of AR.
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    Regulation and distribution of European sea bass perforins point to their role in the adaptive cytotoxic response against NNV
    (2024-01) Garcia Alvarez, M. A.; Cervera Martínez, L.; Valero Cuesta, Y.; Gonzalez Fernandez, C.; Mercado, L.; Chaves Pozo, E.; Cuesta Peñafiel, A.; Biología Celular e Histología
    Cell-mediated cytotoxicity is a complex immune mechanism that involves the release of several killing molecules, being perforin (PRF) one of the most important effector players. Perforin is synthesized by T lymphocytes and natural killer cells in mammals and responsible for the formation of pores on the target cell membrane during the killing process. Although perforin has been extensively studied in higher vertebrates, this knowledge is very limited in fish. Therefore, in this study we have identified four prf genes in European sea bass (Dicentrarchus labrax) and evaluated their mRNA levels. All sea bass prf genes showed the typical and conserved domains of its human orthologue and were closely clustered by the phylogenetic analysis. In addition, all genes showed constitutive and ubiquitous tissular expression, being prf1.9 gene the most highly expressed in immune tissues. Subsequently, in vitro stimulation of head-kidney (HK) cells with phytohemagglutinin, a T-cell activator, showed an increase of all prf gene levels, except for prf1.3 gene. European sea bass HK cells increased the transcription of prf1.2 and prf1.9 during the innate cell-mediated cytotoxic activity against xenogeneic target cells. In addition, sea bass infected with nodavirus (NNV) showed a similar expression pattern of all prf in HK and brain at 15 days post-infection, except for prf1.3 gene and in the gonad. Finally, the use of a polyclonal antibody against PRF1.9 showed an increase of positive cells in HK, brain and gonad from NNV-infected fish. Taken together, the data seem to indicate that all prf genes, except prf1.3, appear to be involved in the European sea bass immunity, and probably in the cell-mediated cytotoxic response, with PRF1.9 playing the most important role against nodavirus. The involvement of the PRFs and the CMC activity in the vertical transmission success of the virus is also discussed.
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    T cell subsets in immunologically-mediated glomerulonephritis
    (Murcia : F. Hernández, 1997) van Alderwegen, I.E.; Bruijn, J.A.; Heer, E.de
    Until recently, research on the pathogenesis of glomerulonephritis has been mainly focused on the characterization of humoral immune responses in the initiation of glomerular injury. However, there is a growing recognition that both cellular and humoral immune responses, in varying proportions, are involved in the pathogenesis of immunologically-mediated glomerulonephritis. T lymphocytes are essential cellular elements of cell-mediated immunity. Both in experimental models of immune-mediated renal disease and in histopathological analyses of human nephropathies, the involvement of T cells has been demonstrated in the immunoregulation of nephritogenic immune responses and in the immune injury in the kidney. T cell activation resulting in either delayed-type hypersensitivity, cytolytic reactions, abnormal expression of major histocompatibility complex (MHC) molecules, or B cell activation can result in glomerulonephritis. These different types of responses are exerted by distinct T cell subsets defined by cell surface markers and cytokine profiles. CD4+ T cells in vivo are functionally heterogeneous with respect to cytokine production and the CD45 isoforms that are found on their surface. Like CD4+ T cells, CD8+ T cells may also be heterogeneous at the leve1 of cytokine production. The roles of CD4+ and CD8+ cells and their cytokine profiles in glomerulonephritis have not been extensively investigated yet, but such studies might improve the understanding of the pathogenesis and possibly lead to new therapeutic approaches of human glomerulonephritis. In this review the role of distinct T lymphocyte subsets in experimental and human glomerulonephritis will be discussed.
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    Tumoricidal potential of binary therapy in lymphoma: Role of DC-NK cross-talk and checkpoint inhibitors
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Chaudhary, Pratima; Yadav, Pragya; Manna, Partha Pratim; Biología Celular e Histología
    Lymphoma is a common type of cancer that occurs in humans. Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL) subtype and is characterized by high clinical and biological heterogeneity. The tumor microenvironment (TME) in lymphoma is critical for the initiation, progression, and metastasis of tumors and influences the therapeutic efficiency of chemotherapy or immuno-therapy, including cell therapy or appropriate combinations of therapeutics. The role of effector immune cells in the development and progression of DLBCL is complex and involves reciprocal interactions between tumor cells, adaptive and innate immune cells, their soluble mediators, and structural components present in the TME. Recruitment of immune cells in the TME and their distinct effects on tumor progression and therapeutic outcomes in the presence of therapy have decisive effects on the outcome of therapy. In this review, we discuss the application and implications of binary therapy involving suboptimal-dose chemotherapy and adoptive cell therapy on the basis of our recent findings on γc cytokine-aided cross-talk between dendritic cells and natural killer cells in therapy against experimental murine lymphoma. This novel therapeutic protocol induces a healing response in experimental lymphoma by downregulating FOXP3 and programmed cell death protein 1. We discuss the various aspects of binary therapy covering multiple issues, including the participation of cell subsets and checkpoint inhibitors in the treatment of malignant lymphoma. These new therapies involve the induction of adoptive cell therapy through the passive transfer of immunologic effectors in addition to a suboptimal dose of adriamycin (doxorubicin hydrochloride) to increase the ability of the immune system to react against tumor antigens, inducing the destruction of tumor cells.