scholarly journals IMMU-35. COMPLEMENT SYSTEM AND GLIOBLASTOMA: AN INTRICATE RELATIONSHIP

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi126-vi126
Author(s):  
Sandeep Mittal ◽  
Shayak Sengupta ◽  
Sabbir Khan ◽  
Kain McGee ◽  
Kristin Alfaro-Munoz ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Complement System ◽  
Complement Activation ◽  
Receptor Expression ◽  
High Expression ◽  
Rt Pcr ◽  
Expression Levels ◽  
Human Gbm ◽  
The Complement System

Abstract The complement system is a vital part of the innate immune system which plays a critical role in immune surveillance and inflammatory processes. Malignant and host cells express various complement inhibitory proteins on their surface to protect against complement mediated cytotoxicity. Imbalanced complement activation triggers inflammation and alters the tumor microenvironment. Complement activation has been shown to induce proliferation and migration of breast, ovarian and lung cancer cells. At this time, the expression and functional role of the complement cascade in glioblastoma (GBM) remain elusive. Here, we investigated the role of complement proteins and their receptor expression in human primary glioma stem-like cells (GSCs) and human GBM tissues. Western blot data demonstrated a high level of expression of central complement components and their receptors in GSCs. RT-PCR data further confirmed the high expression of complement genes which was similar or higher to normal human astrocytes (HA), a cell with high baseline expression levels of complement genes. Flow cytometry analysis revealed that almost 95% of GSCs expressed the anaphylatoxin complement receptors C3aR and C5aR on their cell surfaces which was consistent with our immunohistochemistry analysis of freshly resected GBM tissues. Furthermore, anaphylatoxin C5a exposure increased the proliferation of a subgroup of GSCs while reduced in another subset. Interestingly, C5a exposure was found to increase the expression of various pro-inflammatory markers in GSCs with reduced proliferation. Fluorescence-activated cell sorting (FACS) analysis of freshly isolated human GBM tissue revealed predominant expression of C5aR on cancer cells (CD11b-/CD45- cells) rather than on immune cells. RT-PCR analysis also demonstrated high expression levels of complement genes with concomitant decrease in complement inhibitory genes in human GBM tissue. Evaluation of the differential role of the complement system in GSCs along with their role in in vivo glioma models is ongoing.

scholarly journals Complement Activation Contributes to Severe Acute Respiratory Syndrome Coronavirus Pathogenesis

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Lisa E. Gralinski ◽  
Timothy P. Sheahan ◽  
Thomas E. Morrison ◽  
Vineet D. Menachery ◽  
Kara Jensen ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Host Defense ◽  
Complement System ◽  
Complement Activation ◽  
Fungal Infections ◽  
Central Component ◽  
Lung Pathology ◽  
Inflammatory Monocytes ◽  
The Complement System

ABSTRACT Acute respiratory distress syndrome (ARDS) is immune-driven pathologies that are observed in severe cases of severe acute respiratory syndrome coronavirus (SARS-CoV) infection. SARS-CoV emerged in 2002 to 2003 and led to a global outbreak of SARS. As with the outcome of human infection, intranasal infection of C57BL/6J mice with mouse-adapted SARS-CoV results in high-titer virus replication within the lung, induction of inflammatory cytokines and chemokines, and immune cell infiltration within the lung. Using this model, we investigated the role of the complement system during SARS-CoV infection. We observed activation of the complement cascade in the lung as early as day 1 following SARS-CoV infection. To test whether this activation contributed to protective or pathologic outcomes, we utilized mice deficient in C3 (C3–/–), the central component of the complement system. Relative to C57BL/6J control mice, SARS-CoV-infected C3–/– mice exhibited significantly less weight loss and less respiratory dysfunction despite equivalent viral loads in the lung. Significantly fewer neutrophils and inflammatory monocytes were present in the lungs of C3–/– mice than in C56BL/6J controls, and subsequent studies revealed reduced lung pathology and lower cytokine and chemokine levels in both the lungs and the sera of C3–/– mice than in controls. These studies identify the complement system as an important host mediator of SARS-CoV-induced disease and suggest that complement activation regulates a systemic proinflammatory response to SARS-CoV infection. Furthermore, these data suggest that SARS-CoV-mediated disease is largely immune driven and that inhibiting complement signaling after SARS-CoV infection might function as an effective immune therapeutic. IMPORTANCE The complement system is a critical part of host defense to many bacterial, viral, and fungal infections. It works alongside pattern recognition receptors to stimulate host defense systems in advance of activation of the adaptive immune response. In this study, we directly test the role of complement in SARS-CoV pathogenesis using a mouse model and show that respiratory disease is significantly reduced in the absence of complement even though viral load is unchanged. Complement-deficient mice have reduced neutrophilia in their lungs and reduced systemic inflammation, consistent with the observation that SARS-CoV pathogenesis is an immune-driven disease. These data suggest that inhibition of complement signaling might be an effective treatment option following coronavirus infection.

scholarly journals Role of high expression levels of STK39 in the growth, migration and invasion of non-small cell type lung cancer cells

Oncotarget ◽  
2016 ◽  
Vol 7 (38) ◽  
pp. 61366-61377 ◽  
Author(s):  
Zhao Li ◽  
Wenzhuo Zhu ◽  
Liwen Xiong ◽  
Xiaobo Yu ◽  
Xi Chen ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cancer Cells ◽  
Small Cell ◽  
High Expression ◽  
Lung Cancer Cells ◽  
Migration And Invasion ◽  
Cell Type ◽  
Expression Levels

The Role of the Complement System Classical and Alternative Pathways in the Pathogenesis of Lacrimal Gland Benign Lymphoepithelial Lesions

2021 ◽  
Author(s):  
Rui Liu ◽  
Jing Li ◽  
Mei Sun ◽  
Jinjin Wang ◽  
Nan Wang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Lacrimal Gland ◽  
Complement System ◽  
Immunohistochemical Staining ◽  
Rt Pcr ◽  
Alternative Pathways ◽  
Medical University ◽  
The Complement System ◽  
Lymphoepithelial Lesions

Abstract Objective: The complement system plays an important role in chronic inflammation and autoimmune diseases. On the basis of previous studies, this paper further analyzed the role of the complement system classical pathway and alternative pathway in the pathogenesis of lacrimal gland benign lymphoepithelial lesions (LGBLEL).Methods: Six cases of LGBLEL and six cases of orbital cavernous hemangioma (CH), diagnosed by histopathology in Beijing Tongren Hospital, Capital Medical University, between July 2010 and October 2013 were randomly selected for proteomic analysis. Gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to analyze the signaling pathways of differentially expressed genes and proteins. Four LGBLEL and three orbital CH cases, diagnosed by histopathology in Beijing Tongren Hospital, Capital Medical University, between October 2018 and August 2019, were randomly selected as the experimental group and the control group, respectively. RT-PCR, immunohistochemical staining and western blotting were used to verify the genes and proteins related to the complement system signaling pathway.Results: The expression of complement system signaling pathway in LGBLEL tissue was significantly different (P<0.0001) compared with orbital CH, and C3, C5 and C9 were differentially expressed genes. RT-PCR results showed that mRNA expression levels of C1qA, C3, C5 and C9 related to the complement signaling pathway were higher in LGBLEL tissues than in orbital CH (P<0.0001). Immunohistochemical staining results showed that C1qA, C3, C5 and C9 protein expression was significantly higher in LGBLEL tissues than in orbital CH. Western blotting showed that the levels of C1qA, C3, C5 and C9 proteins were significantly higher in LGBLEL tissues than in orbital CH (P=0.0008; P=0.0375; P=0.0306; P=0.0073, respectively).Conclusion: Both the classical and alternative pathways of complement system are involved in the pathogenesis of LGBLEL.

scholarly journals Role of the Classical Pathway of Complement Activation in Experimentally Induced Polymicrobial Peritonitis

2001 ◽  
Vol 69 (12) ◽  
pp. 7304-7309 ◽  
Author(s):  
Ilhan Celik ◽  
Cordula Stover ◽  
Marina Botto ◽  
Steffen Thiel ◽  
Sotiria Tzima ◽  
...  
Keyword(s):  
Complement System ◽  
Complement Activation ◽  
Immune Defense ◽  
Classical Pathway ◽  
Complement Factor ◽  
Wild Type ◽  
Factor B ◽  
The Complement System ◽  
Deficient Mice

ABSTRACT The complement system and the natural antibody repertoire provide a critical first-line defense against infection. The binding of natural antibodies to microbial surfaces opsonizes invading microorganisms and activates complement via the classical pathway. Both defense systems cooperate within the innate immune response. We studied the role of the complement system in the host defense against experimental polymicrobial peritonitis using mice lacking either C1q or factor B and C2. The C1q-deficient mice lacked the classical pathway of complement activation. The factor B- and C2-deficient mice were known to lack the classical and alternative pathways, and we demonstrate here that these mice also lacked the lectin pathway of complement activation. Using inoculum doses adjusted to cause 42% mortality in the wild-type strain, none of the mice deficient in the three activation routes of complement (factor B and C2 deficient) survived (mortality of 100%). Mortality in mice deficient only in the classical pathway of complement activation (C1q deficient) was 83%. Application of further dilutions of the polymicrobial inoculum showed a dose-dependent decrease of mortality in wild-type controls, whereas no changes in mortality were observed in the two gene-targeted strains. These results demonstrate that the classical activation pathway is required for an effective antimicrobial immune defense in polymicrobial peritonitis and that, in the infection model used, the remaining antibody-independent complement activation routes (alternative and lectin pathways) provide a supporting line of defense to gain residual protection in classical pathway deficiency.

scholarly journals Platelets Promote Activation of the Complement System in Ovarian Cancer

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4970-4970
Author(s):  
Omayra Gonzalez Pagan ◽  
Min Soon Cho ◽  
Vahid Afshar-Kharghan
Keyword(s):  
Ovarian Cancer ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Complement System ◽  
Complement Activation ◽  
Platelet Inhibition ◽  
Ovarian Cancer Cells ◽  
Murine Models ◽  
Mesenchymal Transition ◽  
The Complement System

Abstract Platelets promote metastasis and growth of ovarian cancer. We have shown that platelets extravasate into the tumor microenvironment (TME) and increase proliferation and epithelial-mesenchymal transition (EMT) in ovarian cancer cells. We have also shown that activation of the complement system in TME of ovarian cancer enhances tumor growth. Ovarian cancer cells secrete complement proteins that upon activation in the TME increase proliferation of cancer cells and promote EMT via an autocrine pathway. The activators of the complement system in the TME have not been identified. We have demonstrated that upon activation platelets activate the complement system on their surface. In the current study, we examined whether extravasated platelets inside tumors contribute to the complement activation in the TME. 1) We examined the effect of antiplatelet reagents on platelet extravasation into TME, using murine models of ovarian cancer. Tumors induced by injection of ovarian cancer cells into the peritoneum of Nu/Nu mice were resected after 6-8 weeks and the number of extravasated platelets was determined by immunostaining tumor sections and counting the number CD42 (GPIb) positive cells that were outside the blood vessels (CD31 positive). We found that platelet extravasation is an active process and platelet inhibition by aspirin or ticagrelor reduces the number of extravasated platelets. Furthermore, P2Y12 deficient platelets extravasate less than normal platelets. In all of these experiments, the number of extravasated red blood cells were significantly less than extravasated platelets and was not affected by the inhibition of platelets. 2) We examined the effect of platelet inhibition on the activation of the complement system in the TME. We immunostained resected tumors from aspirin- or ticagrelor-treated tumor-bearingmice and from P2Y12-deficient tumor-bearingmice for the endproductof complement activation (C5b-9 or membrane attack complex). Inhibition of platelet function by aspirin or ticagrelor,or the presence of hypoactive platelets in P2Y12 deficient mice reduced the amount of C5b-9 deposited in the tumors induced in murine models of ovarian cancer. Our result showed that complement activation in the TME is at least partially dependent onextravasated platelets. We propose that platelets in addition to directly increasing proliferation of ovarian cancer cells, also enhance tumor growth by activating the complement system in the vicinity of cancer cells. Our study links platelets, complement activation, and ovarian cancer growth; and raises the possibility of using antiplatelet reagents and complement inhibitors as novel synergisticanti-tumor reagents in ovarian cancer. Disclosures No relevant conflicts of interest to declare.

scholarly journals Special Issue: The Role of Complement in Cancer Immunotherapy

Antibodies ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 29
Author(s):  
Ronald P. Taylor
Keyword(s):  
Cancer Immunotherapy ◽  
Complement System ◽  
Immune Defense ◽  
Special Issue ◽  
The Complement System ◽  
Critical Aspects

The complement system plays an important role in critical aspects of immune defense and in the maintenance of homeostasis in the bloodstream, as well as in essentially all tissues and organs [...]

The role of the complement system in hereditary angioedema

2017 ◽  
Vol 89 ◽  
pp. 59-68 ◽  
Author(s):  
Dorottya Csuka ◽  
Nóra Veszeli ◽  
Lilian Varga ◽  
Zoltán Prohászka ◽  
Henriette Farkas
Keyword(s):  
Complement System ◽  
Hereditary Angioedema ◽  
The Complement System

Aberrant activation of complement system in renal grafts is mediated by cold storage

2021 ◽  
Author(s):  
Sorena Lo ◽  
Li Jiang ◽  
Savannah Stacks ◽  
Haixia Lin ◽  
Nirmala Parajuli
Keyword(s):  
Cold Storage ◽  
Complement System ◽  
Complement Activation ◽  
Renal Tubules ◽  
Renal Transplants ◽  
Reducing Conditions ◽  
Tnf Α ◽  
Renal Grafts ◽  
The Impact ◽  
The Complement System

Aberrant complement activation leads to tissue damage during kidney transplantation, and it is recognized as an important target for therapeutic intervention (6, 19, 35, 64). However, it is not clear whether cold storage (CS) triggers the complement pathway in transplanted kidneys. The goal of this study was to determine the impact of CS on complement activation in renal transplants. Male Lewis and Fischer rats were used, and donor rat kidneys were exposed to 4 h or 18 h of CS followed by transplantation (CS+Transplant). To study CS-induced effects, a group with no CS was included in which the kidney was removed and transplanted back to the same rat (autotransplantation, ATx). Complement proteins (C3 and C5b-9) were evaluated with western blotting (reducing and non-reducing conditions) and immunostaining. Western blot of renal extracts or serum indicated that the levels of C3 and C5b-9 increased after CS+Transplant compared to ATx. Quite strikingly, intracellular C3 was profoundly elevated within renal tubules after CS+Transplant but was absent in Sham or ATx groups, which showed only extratubular C3. Similarly, C5b-9 immunofluorescence staining of renal sections showed an increase in C5b-9 deposits in kidneys after CS+Transplant. Real-time PCR (SYBR Green) showed increased expression of CD11b and CD11c, components of complement receptors 3 and 4, respectively, as well as inflammatory markers such as TNF-α. In addition, recombinant TNF-α significantly increased C3 levels in renal cells. Collectively, these results demonstrate that CS activates the complement system in renal transplants.

scholarly journals Assessment of TRPV4 Channel and Its Role in Colorectal Cancer Cells

2019 ◽  
Vol 12 (2) ◽  
pp. 629-638
Author(s):  
N. N. Bahari ◽  
S. Y. N. Jamaludin ◽  
A. H. Jahidin ◽  
M. N. Zahary ◽  
A. B. Mohd Hilmi
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle ◽  
Cell Death ◽  
Cancer Cells ◽  
Human Colorectal Cancer ◽  
Expression Levels ◽  
Pharmacological Modulation ◽  
Colorectal Cancer Cells ◽  
Ht 29

The transient receptor potential vanilloid member 4 (TRPV4) is a non-selective calcium (Ca2+)-permeable channel which is widely expressed in different types of tissues including the lungs, liver, kidneys and salivary gland. TRPV4 has been shown to serve as a cellular sensor where it is involved in processes such as osmoregulation, cell volume regulation and thermoregulation. Emerging evidence suggests that TRPV4 also plays important roles in several aspects of cancer progression. Despite the reported roles of TRPV4 in several forms of cancers, the role of TRPV4 in human colorectal cancer remains largely unexplored. In the present study, we sought to establish the potential role of TRPV4 in colorectal cancer by assessing TRPV4 expression levels and investigating whether TRPV4 pharmacological modulation may alter cell proliferation, cell cycle and cell death in colorectal cancer cells. Quantitative real-time PCR analysis revealed that TRPV4 mRNA levels were significantly lower in HT-29 cells than normal colon CCD-18Co cells. However, TRPV4 mRNA was absent in HCT-116 cells. Pharmacological activation of TRPV4 with GSK1016790A significantly enhanced the proliferation of HT-29 cells while TRPV4 inhibition using RN 1734 decreased their proliferation. Increased proliferation in GSK1016790A-treated HT-29 cells was attenuated by co-treatment with RN 1734. Pharmacological modulation of TRPV4 had no effect on the cell cycle progression but promoted cell death in HT-29 cells. Taken together, these findings suggest differential TRPV4 expression levels in human colorectal cancer cells and that pharmacological modulation of TRPV4 produces distinct effects on the proliferation and induces cell death in HT-29 cells.

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