scholarly journals Humoral First-Line Mucosal Innate Defence in vivo

2020 ◽  
Vol 12 (5) ◽  
pp. 373-386
Author(s):  
Carl Persson
Keyword(s):  
First Line ◽  
Innate Defence

scholarly journals The loss of SHMT2 mediates 5-fluorouracil chemoresistance in colorectal cancer by upregulating autophagy

Oncogene ◽  
2021 ◽  
Author(s):  
Jian Chen ◽  
Risi Na ◽  
Chao Xiao ◽  
Xiao Wang ◽  
Yupeng Wang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Patient Survival ◽  
Serine Hydroxymethyltransferase ◽  
First Line ◽  
Xenograft Models ◽  
Potential Opportunity ◽  
First Line Treatment ◽  
Novel Therapeutic

Abstract5-Fluorouracil (5-FU)-based chemotherapy is the first-line treatment for colorectal cancer (CRC) but is hampered by chemoresistance. Despite its impact on patient survival, the mechanism underlying chemoresistance against 5-FU remains poorly understood. Here, we identified serine hydroxymethyltransferase-2 (SHMT2) as a critical regulator of 5-FU chemoresistance in CRC. SHMT2 inhibits autophagy by binding cytosolic p53 instead of metabolism. SHMT2 prevents cytosolic p53 degradation by inhibiting the binding of p53 and HDM2. Under 5-FU treatment, SHMT2 depletion promotes autophagy and inhibits apoptosis. Autophagy inhibitors decrease low SHMT2-induced 5-FU resistance in vitro and in vivo. Finally, the lethality of 5-FU treatment to CRC cells was enhanced by treatment with the autophagy inhibitor chloroquine in patient-derived and CRC cell xenograft models. Taken together, our findings indicate that autophagy induced by low SHMT2 levels mediates 5-FU resistance in CRC. These results reveal the SHMT2–p53 interaction as a novel therapeutic target and provide a potential opportunity to reduce chemoresistance.

scholarly journals Inhibition of platelet phagocytosis as an in vitro predictor for therapeutic potential of RBC antibodies in murine ITP

Blood ◽  
2020 ◽  
Vol 135 (26) ◽  
pp. 2420-2424 ◽  
Author(s):  
Ramsha Khan ◽  
Melissa Menard ◽  
Chao-Ching Jen ◽  
Xi Chen ◽  
Peter A. A. Norris ◽  
...  
Keyword(s):  
Blood Cells ◽  
Immune Thrombocytopenia ◽  
Therapeutic Potential ◽  
Sufficient Condition ◽  
First Line ◽  
Phagocytosis Assay ◽  
First Line Therapy ◽  
Line Therapy

Abstract Polyclonal anti-D is a first-line therapy for immune thrombocytopenia (ITP). Monoclonal antibodies are desirable alternatives, but none have yet proven successful despite their ability to opsonize erythrocytes (or red blood cells, RBCs) and cause anemia. Here, we examined 12 murine erythrocyte–specific antibodies of different specificity and subtypes and found that 8 of these antibodies could induce anemia in antigen-positive mice. Of these 8 antibodies, only 5 ameliorated ITP. All antibodies were examined for their in vitro ability to support macrophage-mediated phagocytosis of erythrocytes. Antibodies which supported erythrocyte phagocytosis in vitro successfully ameliorated ITP in vivo. To examine the ability of each antibody to inhibit phagocytosis of platelets, the antibodies were used to sensitize erythrocytes in vitro and these were added to a platelet phagocytosis assay. Antibodies that inhibited platelet phagocytosis in vitro also all ameliorated ITP in vivo. We conclude that inducing anemia is not a sufficient condition for amelioration of ITP but that the antibody’s ability to prevent platelet phagocytosis in vitro predicted its ability to ameliorate ITP. We suggest that inhibition of in vitro platelet phagocytosis may prove to be a valuable tool for determining which erythrocyte antibodies would likely be candidates for clinical use in ITP.

scholarly journals Identification of Metabolically Quiescent Leishmania mexicana Parasites in Peripheral and Cured Dermal Granulomas Using Stable Isotope Tracing Imaging Mass Spectrometry

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Joachim Kloehn ◽  
Berin A. Boughton ◽  
Eleanor C. Saunders ◽  
Sean O’Callaghan ◽  
Katrina J. Binger ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Heavy Water ◽  
Large Population ◽  
Imaging Mass Spectrometry ◽  
Host Cells ◽  
Microbial Pathogens ◽  
Mammalian Host ◽  
Leishmania Mexicana ◽  
First Line

ABSTRACT Leishmania are sandfly-transmitted protists that induce granulomatous lesions in their mammalian host. Although infected host cells in these tissues can exist in different activation states, the extent to which intracellular parasites stages also exist in different growth or physiological states remains poorly defined. Here, we have mapped the spatial distribution of metabolically quiescent and active subpopulations of Leishmania mexicana in dermal granulomas in susceptible BALB/c mice, using in vivo heavy water labeling and ultra high-resolution imaging mass spectrometry. Quantitation of the rate of turnover of parasite and host-specific lipids at high spatial resolution, suggested that the granuloma core comprised mixed populations of metabolically active and quiescent parasites. Unexpectedly, a significant population of metabolically quiescent parasites was also identified in the surrounding collagen-rich, dermal mesothelium. Mesothelium-like tissues harboring quiescent parasites progressively replaced macrophage-rich granuloma tissues following treatment with the first-line drug, miltefosine. In contrast to the granulomatous tissue, neither the mesothelium nor newly deposited tissue sequestered miltefosine. These studies suggest that the presence of quiescent parasites in acute granulomatous tissues, together with the lack of miltefosine accumulation in cured lesion tissue, may contribute to drug failure and nonsterile cure. IMPORTANCE Many microbial pathogens switch between different growth and physiological states in vivo in order to adapt to local nutrient levels and host microbicidal responses. Heterogeneity in microbial growth and metabolism may also contribute to nongenetic mechanisms of drug resistance and drug failure. In this study, we have developed a new approach for measuring spatial heterogeneity in microbial metabolism in vivo using a combination of heavy water (2H2O) labeling and imaging mass spectrometry. Using this approach, we show that lesions contain a patchwork of metabolically distinct parasite populations, while the underlying dermal tissues contain a large population of metabolically quiescent parasites. Quiescent parasites also dominate drug-depleted tissues in healed animals, providing an explanation for failure of some first line drugs to completely eradicate parasites. This approach is broadly applicable to study the metabolic and growth dynamics in other host-pathogen interactions.

scholarly journals DRES-07. TMZ-LEV- IFN COCKTAIL REGIMEN SIGNIFICANTLY INHIBITED THE GROWTH OF GLIOMA IN VIVO

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi72-vi73
Author(s):  
Xiang-rong Ni ◽  
Jing Wang ◽  
Fu-rong Chen ◽  
Hai-ping Cai ◽  
Yan-jiao Yu ◽  
...  
Keyword(s):  
Protein Expression ◽  
Tumor Growth ◽  
Tumor Volume ◽  
Control Group ◽  
First Line ◽  
Killing Effect ◽  
Treatment Groups ◽  
Mgmt Protein ◽  
Tumor Killing

Abstract OBJECTIVE Temozolomide (TMZ), is the first line chemotherapeutic drug for glioma. Previous studies have suggested that interferon (IFN) and levetiracetam (LEV) could respectively reverse the resistance of TMZ by down-regulating MGMT expression. This study, we aim to investigate the therapeutic effect of a cocktail chemotherapy regimen combining TMZ, LEV, IFN in vivo. METHODS Glioma cell lines U251 and SKMG-4 (MGMT protein expression positive), U138 and GSC-1(MGMT protein expression negative) were used for producing xenograft tumors. The xenograft tumors were established by subcutaneously injecting 1×106 glioma cells into female BALB/C nude mice and divided into 5 treatment groups: Control, TMZ, TMZ+IFN, TMZ+LEV, TMZ+LEV+IFN. The treatment with TMZ (50 mg/kg, i.p.), IFN (2×105 IU, s.c.), LEV (150 mg/kg, i.p.) once a day for five consecutive days and xenograft tumors were measured every two days. RESULTS We identified that U138, U251, SKMG-4 tumor growth among TMZ, TMZ+IFN, TMZ+LEV, TMZ+LEV+IFN were all significantly inhibited (P< 0.05), compared with the control. As for U251 and SKMG-4, tumor killing effect of all 4 treatment groups were not different (P > 0.05). In the treatment of mice bearing U138 glioma, the tumor weight of TMZ+LEV+IFN (0.2688±0.1169 g) group was the lowest and significantly lower than that of TMZ+LEV (0.6574±0.08174g, P=0.0261), TMZ+IFN(0.6108±0.07317 g, P=0.0381), and TMZ (0.9054±0.07154 g, P=0.0017) group. Glioma stem cells GSC-1 was highly resistant to TMZ, tumor volume of TMZ group was not different from control group (P >0.05). While compared with TMZ (1.993±0.1274 g) group, in TMZ+IFN (1.506±0.1223g, P=0.0203), TMZ+LEV (1.178±0.1807g, P=0.0042), and TMZ+LEV+IFN (1.049±0.2171 g, P=0.0038) groups, GSC-1 tumor growth were significantly inhibited(P< 0.05). CONCLUSION Our data demonstrate that both IFN and LEV can sensitize TMZ effect on glioma in vivo, even for MGMT(+) tumors, and TMZ-LEV-IFN cocktail regimen seems the best. Key words: glioma, TMZ, LEV, IFN

scholarly journals Pulmonary Surfactant Protein D in First-Line Innate Defence against Influenza A Virus Infections

2013 ◽  
Vol 5 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Marine L.B. Hillaire ◽  
Henk P. Haagsman ◽  
Albert D.M.E. Osterhaus ◽  
Guus F. Rimmelzwaan ◽  
Martin van Eijk
Keyword(s):  
Influenza A Virus ◽  
Pulmonary Surfactant ◽  
Influenza A ◽  
Surfactant Protein ◽  
Surfactant Protein D ◽  
Virus Infections ◽  
First Line ◽  
Innate Defence ◽  
Pulmonary Surfactant Protein

scholarly journals Early Bactericidal Activity and Pharmacokinetics of the Diarylquinoline TMC207 in Treatment of Pulmonary Tuberculosis

2008 ◽  
Vol 52 (8) ◽  
pp. 2831-2835 ◽  
Author(s):  
R. Rustomjee ◽  
A. H. Diacon ◽  
J. Allen ◽  
A. Venter ◽  
C. Reddy ◽  
...  
Keyword(s):  
Pulmonary Tuberculosis ◽  
Bactericidal Activity ◽  
Dose Range ◽  
Study Drug ◽  
First Line ◽  
Serious Adverse Events ◽  
Once Daily ◽  
Smear Positive Pulmonary Tuberculosis

ABSTRACT Tibotec Medicinal Compound 207 (TMC207) is a novel diarylquinoline with a unique mode of action that targets mycobacterial ATP synthase. TMC207 exhibits high in vitro activity against mycobacterial strains either susceptible or resistant to all first-line and many second-line drugs, including fluoroquinolones, and has shown exceptional in vivo activity against several mycobacterial species in different animal models. In this early bactericidal activity study, 75 treatment-naïve patients with smear-positive pulmonary tuberculosis were randomized to once-daily oral TMC207 (25 mg, 100 mg, or 400 mg), 600 mg rifampin (RIF), or 300 mg isoniazid (INH) for 7 days. Sixteen-hour overnight sputum collected at baseline and on each treatment day was plated in serial dilutions on selective agar plates. The bactericidal activity was expressed as the log10 decrease in CFU/ml sputum/day. Pharmacokinetic sampling was performed on day 7 of TMC207 administration up to 24 h postdose. The decreases in log10 CFU counts (± standard deviation) from baseline to day 7 were 0.04 ± 0.46 for 25 mg TMC207 (n = 14), 0.26 ± 0.64 for 100 mg TMC207 (n = 14), 0.77 ± 0.58 for 400 mg TMC207 (n = 14), 1.88 ± 0.74 for INH (n = 11), and 1.70 ± 0.71 for RIF (n = 14). Significant bactericidal activity of 400 mg TMC207 was observed from day 4 onward and was similar in magnitude to those of INH and RIF over the same period. The pharmacokinetics of TMC207 were linear across the dose range. In summary, TMC207 demonstrated bactericidal activity with a delayed onset and was well tolerated, and no study drug-related serious adverse events occurred.

scholarly journals In vivo effect of two first-line ART regimens on inflammatory mediators in male HIV patients

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Vasiliki D Papakonstantinou ◽  
Maria Chini ◽  
Nikos Mangafas ◽  
George M Stamatakis ◽  
Nickolaos Tsogas ◽  
...  
Keyword(s):  
Inflammatory Mediators ◽  
First Line ◽  
Hiv Patients

scholarly journals First-Choice Antibiotics at Subinhibitory Concentrations Induce Persistence of Chlamydia pneumoniae

2004 ◽  
Vol 48 (4) ◽  
pp. 1402-1405 ◽  
Author(s):  
Jens Gieffers ◽  
Jan Rupp ◽  
Andreas Gebert ◽  
Werner Solbach ◽  
Matthias Klinger
Keyword(s):  
Gene Expression ◽  
Membrane Proteins ◽  
Chlamydia Pneumoniae ◽  
Growth Forms ◽  
Chronic Infections ◽  
First Line ◽  
First Choice ◽  
Subinhibitory Concentrations

ABSTRACT Persistent growth forms of Chlamydia pneumoniae have been associated with chronic infections in vivo. We investigated the effects of first-line therapeutics on the induction of persistence by monitoring recoverable organisms, gene expression of membrane proteins, and morphology. We found that all of the antibiotics tested have distinct and subinhibitory concentrations at which they induce persistence.

scholarly journals Targeting the TR4 nuclear receptor-mediated lncTASR/AXL signaling with tretinoin increases the sunitinib sensitivity to better suppress the RCC progression

Oncogene ◽  
2019 ◽  
Vol 39 (3) ◽  
pp. 530-545 ◽  
Author(s):  
Hangchuan Shi ◽  
Yin Sun ◽  
Miao He ◽  
Xiong Yang ◽  
Michiaki Hamada ◽  
...  
Keyword(s):  
Small Molecules ◽  
Nuclear Receptor ◽  
Preclinical Study ◽  
First Line ◽  
Novel Therapy ◽  
Signaling Mechanism ◽  
First Line Therapy ◽  
Line Therapy ◽  
The Stability

Abstract Renal cell carcinoma (RCC) is one of the most lethal urological tumors. Using sunitinib to improve the survival has become the first-line therapy for metastatic RCC patients. However, the occurrence of sunitinib resistance in the clinical application has curtailed its efficacy. Here we found TR4 nuclear receptor might alter the sunitinib resistance to RCC via altering the TR4/lncTASR/AXL signaling. Mechanism dissection revealed that TR4 could modulate lncTASR (ENST00000600671.1) expression via transcriptional regulation, which might then increase AXL protein expression via enhancing the stability of AXL mRNA to increase the sunitinib resistance in RCC. Human clinical surveys also linked the expression of TR4, lncTASR, and AXL to the RCC survival, and results from multiple RCC cell lines revealed that targeting this newly identified TR4-mediated signaling with small molecules, including tretinoin, metformin, or TR4-shRNAs, all led to increase the sunitinib sensitivity to better suppress the RCC progression, and our preclinical study using the in vivo mouse model further proved tretinoin had a better synergistic effect to increase sunitinib sensitivity to suppress RCC progression. Future successful clinical trials may help in the development of a novel therapy to better suppress the RCC progression.

scholarly journals Inhibition of FGF2-Mediated Signaling in GIST—Promising Approach for Overcoming Resistance to Imatinib

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1674
Author(s):  
Sergei Boichuk ◽  
Aigul Galembikova ◽  
Ekaterina Mikheeva ◽  
Firuza Bikinieva ◽  
Aida Aukhadieva ◽  
...  
Keyword(s):  
Tumor Response ◽  
Molecular Target ◽  
Compensatory Mechanism ◽  
Dependent Manner ◽  
First Line ◽  
Induced Apoptosis ◽  
First Time ◽  
Malignant Behavior ◽  
First Line Treatment

Inhibition of KIT-signaling is a major molecular target for gastrointestinal stromal tumor (GIST) therapy, and imatinib mesylate (IM) is known as the most effective first-line treatment option for patients with advanced, unresectable, and/or metastatic GISTs. We show here for the first time that the inhibition of KIT-signaling in GISTs induces profound changes in the cellular secretome, leading to the release of multiple chemokines, including FGF-2. IM increased migration, invasion, and colony formation of IM-resistant GISTs in an FGF2-dependent manner, whereas the use of blocking anti-FGF2 antibodies or BGJ398, a selective FGFR inhibitor, abolished these effects, thus suggesting that the activation of FGF2-mediated signaling could serve as a compensatory mechanism of KIT-signaling inhibited in GISTs. Conversely, FGF-2 rescued the growth of IM-naive GISTs treated by IM and protected them from IM-induced apoptosis, consistent with the possible involvement of FGF-2 in tumor response to IM-based therapy. Indeed, increased FGF-2 levels in serum and tumor specimens were found in IM-treated mice bearing IM-resistant GIST xenografts, whereas BGJ398 used in combination with IM effectively inhibited their growth. Similarly, increased FGF-2 expression in tumor specimens from IM-treated patients revealed the activation of FGF2-signaling in GISTs in vivo. Collectively, the continuation of IM-based therapy for IM-resistant GISTs might facilitate disease progression by promoting the malignant behavior of tumors in an FGF2-dependent manner. This provides a rationale to evaluate the effectiveness of the inhibitors of FGF-signaling for IM-resistant GISTs.

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