scholarly journals Stronger In Vitro Phagocytosis by Monocytes-Macrophages Is Indicative of Greater Pathogen Clearance and Antibody Levels In Vivo

2008 ◽  
Vol 87 (9) ◽  
pp. 1725-1733 ◽  
Author(s):  
S.F. Sun ◽  
Q.Z. Pan ◽  
X. Hui ◽  
B.L. Zhang ◽  
H.M. Wu ◽  
...  
Keyword(s):  
Antibody Levels ◽  
Pathogen Clearance

scholarly journals Increased Severity of Local and Systemic Anaphylactic Reactions in Gp49b1-Deficient Mice

2001 ◽  
Vol 194 (2) ◽  
pp. 227-234 ◽  
Author(s):  
Massoud Daheshia ◽  
Daniel S. Friend ◽  
Michael J. Grusby ◽  
K. Frank Austen ◽  
Howard R. Katz
Keyword(s):  
Mast Cell ◽  
Cell Activation ◽  
Mast Cell Activation ◽  
Critical Question ◽  
Increased Sensitivity ◽  
Antibody Levels ◽  
Deficient Mice

gp49B1 is an immunoglobulin (Ig) superfamily member that inhibits FcεRI-induced mast cell activation when the two receptors are coligated with antibodies in vitro. The critical question of in vivo function of gp49B1 is now addressed in gene-disrupted mice. gp49B1-deficient mice exhibited a significantly increased sensitivity to IgE-dependent passive cutaneous anaphylaxis as assessed by greater tissue swelling and mast cell degranulation in situ. Importantly, by the same criteria, the absence of gp49B1 also resulted in a lower threshold for antigen challenge in active cutaneous anaphylaxis, in which the antigen-specific antibody levels were comparable in gp49B1-deficient and sufficient mice. Moreover, the absence of gp49B1 resulted in a significantly greater and faster death rate in active systemic anaphylaxis. These results indicate that gp49B1 innately dampens adaptive immediate hypersensitivity responses by suppressing mast cell activation in vivo. In addition, this study provides a new concept and target for regulation of allergic disease susceptibility and severity.

scholarly journals Deletion of the Gene for the Type I Interferon Inhibitor I329L from the Attenuated African Swine Fever Virus OURT88/3 Strain Reduces Protection Induced in Pigs

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 262 ◽  
Author(s):  
Ana Luisa Reis ◽  
Lynnette C. Goatley ◽  
Tamara Jabbar ◽  
Elisabeth Lopez ◽  
Anusyah Rathakrishnan ◽  
...  
Keyword(s):  
Type I Interferon ◽  
African Swine Fever Virus ◽  
Clinical Signs ◽  
African Swine Fever ◽  
Type I ◽  
Lethal Challenge ◽  
Host Innate Immune Response ◽  
Antibody Levels

Live attenuated vaccines are considered to be the fastest route to the development of a safe and efficacious African swine fever (ASF) vaccine. Infection with the naturally attenuated OURT88/3 strain induces protection against challenge with virulent isolates from the same or closely related genotypes. However, adverse clinical signs following immunisation have been observed. Here, we attempted to increase the OURT88/3 safety profile by deleting I329L, a gene previously shown to inhibit the host innate immune response. The resulting virus, OURT88/3ΔI329L, was tested in vitro to evaluate the replication and expression of type I interferon (IFN) and in vivo by immunisation and lethal challenge experiments in pigs. No differences were observed regarding replication; however, increased amounts of both IFN-β and IFN-α were observed in macrophages infected with the deletion mutant virus. Unexpectedly, the deletion of I329L markedly reduced protection against challenge with the virulent OURT88/1 isolate. This was associated with a decrease in both antibody levels against VP72 and the number of IFN-γ-producing cells in the blood of non-protected animals. Furthermore, a significant increase in IL-10 levels in serum was observed in pigs immunised with OURT88/3ΔI329L following challenge. Interestingly, the deletion of the I329L gene failed to attenuate the virulent Georgia/2007 isolate.

scholarly journals Neutrophil-derived alpha defensins control inflammation by inhibiting macrophage mRNA translation

2016 ◽  
Vol 113 (16) ◽  
pp. 4350-4355 ◽  
Author(s):  
Matthew Brook ◽  
Gareth H. Tomlinson ◽  
Katherine Miles ◽  
Richard W. P. Smith ◽  
Adriano G. Rossi ◽  
...  
Keyword(s):  
Mrna Translation ◽  
Protein Translation ◽  
In Vitro Translation ◽  
Human Neutrophils ◽  
Translation System ◽  
Serovar Typhimurium ◽  
The Unfolded Protein Response ◽  
Pathogen Clearance

Neutrophils are the first and most numerous cells to arrive at the site of an inflammatory insult and are among the first to die. We previously reported that alpha defensins, released from apoptotic human neutrophils, augmented the antimicrobial capacity of macrophages while also inhibiting the biosynthesis of proinflammatory cytokines. In vivo, alpha defensin administration protected mice from inflammation, induced by thioglychollate-induced peritonitis or following infection with Salmonella enterica serovar Typhimurium. We have now dissected the antiinflammatory mechanism of action of the most abundant neutrophil alpha defensin, Human Neutrophil Peptide 1 (HNP1). Herein we show that HNP1 enters macrophages and inhibits protein translation without inducing the unfolded-protein response or affecting mRNA stability. In a cell-free in vitro translation system, HNP1 powerfully inhibited both cap-dependent and cap-independent mRNA translation while maintaining mRNA polysomal association. This is, to our knowledge, the first demonstration of a peptide released from one cell type (neutrophils) directly regulating mRNA translation in another (macrophages). By preventing protein translation, HNP1 functions as a “molecular brake” on macrophage-driven inflammation, ensuring both pathogen clearance and the resolution of inflammation with minimal bystander tissue damage.

scholarly journals Enhancing the Immune Response of a Nicotine Vaccine with Synthetic Small “Non-Natural” Peptides

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1290
Author(s):  
Hoang-Thanh Le ◽  
Nya L. Fraleigh ◽  
Jordan D. Lewicky ◽  
Justin Boudreau ◽  
Paul Dolinar ◽  
...  
Keyword(s):  
Immune Response ◽  
Delivery System ◽  
Solid Phase ◽  
Ex Vivo ◽  
Successful Vaccine ◽  
Adjuvant Vaccine ◽  
Natural Peptides ◽  
Antibody Levels

The addictive nature of nicotine is likely the most significant reason for the continued prevalence of tobacco smoking despite the widespread reports of its negative health effects. Nicotine vaccines are an alternative to the currently available smoking cessation treatments, which have limited efficacy. However, the nicotine hapten is non-immunogenic, and successful vaccine formulations to treat nicotine addiction require both effective adjuvants and delivery systems. The immunomodulatory properties of short, non-natural peptide sequences not found in human systems and their ability to improve vaccine efficacy continue to be reported. The aim of this study was to determine if small “non-natural peptides,” as part of a conjugate nicotine vaccine, could improve immune responses. Four peptides were synthesized via solid phase methodology, purified, and characterized. Ex vivo plasma stability studies using RP-HPLC confirmed that the peptides were not subject to proteolytic degradation. The peptides were formulated into conjugate nicotine vaccine candidates along with a bacterial derived adjuvant vaccine delivery system and chitosan as a stabilizing compound. Formulations were tested in vitro in a dendritic cell line to determine the combination that would elicit the greatest 1L-1β response using ELISAs. Three of the peptides were able to enhance the cytokine response above that induced by the adjuvant delivery system alone. In vivo vaccination studies in BALB/c mice demonstrated that the best immune response, as measured by nicotine-specific antibody levels, was elicited from the conjugate vaccine structure, which included the peptide, as well as the other components. Isotype analyses highlighted that the peptide was able to shift immune response toward being more humorally dominant. Overall, the results have implications for the use of non-natural peptides as adjuvants not only for the development of a nicotine vaccine but also for use with other addictive substances and conventional vaccination targets as well.

scholarly journals 886 Targeting VSIG4, a novel macrophage checkpoint, repolarizes suppressive macrophages which induces an inflammatory response in primary cell in vitro assays and fresh human tumor cultures

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A928-A928
Author(s):  
Steve Sazinsky ◽  
Phuong Nguyen ◽  
Mohammad Zafari ◽  
Ryan Phennicie ◽  
Joe Wahle ◽  
...  
Keyword(s):  
Lung Cancer ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Ex Vivo ◽  
Syngeneic Mouse ◽  
Pathogen Clearance

BackgroundVSIG4 (V-set immunoglobulin-domain-containing 4) is a B7 family related protein with known roles as a complement receptor involved in pathogen clearance as well as a negative regulator of T cell activation by an undetermined mechanism.1–3 VSIG4 is expressed in tumor associated macrophages (TAMs) with exquisite specificity. In cancer, increased expression of VSIG4 has been associated with worse survival in multiple indications, including non-small cell lung cancer, multiple myeloma, ovarian cancer, and glioma, suggesting an important role in tumor immune evasion.3–6 Based upon computational analysis of transcript data across thousands of primary cancer and normal tissue samples, we hypothesized that VSIG4 has an important regulatory role in promoting M2-like immune suppressive macrophages in the tumor microenvironment, and that targeting VSIG4 via a monoclonal antibody could relieve VSIG4-mediated macrophage suppression by repolarizing TAMs to an inflammatory phenotype capable of coordinating an anti-tumor immune response.MethodsThe ability of anti-VSIG4 antibodies to repolarize M2-like macrophages and induce T cell activation was assessed in vitro and ex vivo, by measuring production of inflammatory mediators. In vitro assays were performed primarily with M-CSF plus IL-10 driven monocyte-derived M2c macrophages from healthy donors. Ex vivo assays were performed with fresh, patient-derived tumor samples in culture. To determine whether targeting VSIG4 can lead to an anti-tumor effect in vivo, syngeneic mouse models were dosed with anti-mouse VSIG4 antibodies and characterized for changes in tumor volume and immune cell populations.ResultsIn in vitro and ex vivo assays anti-VSIG4 antibodies repolarize M2 macrophages and induce an immune response culminating in T cell activation. Targeting VSIG4 upregulates pro-inflammatory cytokines in M2c macrophages, as well as upregulates pro-inflammatory myeloid-derived cytokines and T cell-derived cytokines in M2c macrophages co-cultured with autologous T cells in the presence of staphylococcal enterotoxin B (SEB) activation. To assess targeting VSIG4 in a relevant translational model, fresh, patient-derived tumor samples were treated ex vivo with anti-VSIG4. Across multiple tumor types, anti-VSIG4 treatment resulted in a significant upregulation of cytokines involved in TAM repolarization and T cell activation, and chemokines involved in immune cell recruitment, at levels greater than observed by treatment with anti-PD-1 or a clinical macrophage repolarizing agent (anti-ILT-4). In vivo, tumor growth inhibition is observed in syngeneic mouse models dosed with anti-mouse-VSIG4 alone and in combination with anti-PD-1.ConclusionsTaken together, these data suggest that VSIG4 represents a promising new target capable of stimulating an anti-cancer response via multiple key immune mechanisms.Referencesvan Lookeren Campagne M, Verschoor A. Pathogen clearance and immune adherence “revisited”: immuno-regulatory roles for CRIg. Semin Immunol 2018;37:4–11.Xu S, Sun Z, Li L, Liu J, He J, Song D, Shan G, Liu H, Wu X. Induction of T cells suppression by dendritic cells transfected with VSIG4 recombinant adenovirus. Immunol Lett 2010;128(1):46–50.Liao Y, Guo S, Chen Y, Cao D, Xu H, Yang C, Fei L, Ni B, Ruan Z. VSIG4 expression on macrophages facilitates lung cancer development. Lab Invest 2014;94(7):706–715.Roh J, Jeon Y, Lee A, Lee S, Kim Y, Sung C, Park C, Hong J, Yoon D, Suh C, Huh J, Choi I, Park C. The immune checkpoint molecule V-set Ig domain-containing 4 is an independent prognostic factor for multiple myeloma. Oncotarget 2017;8(35):58122–58132.Xu T, Jiang Y, Yan Y, Wang H, Lu C, Xu H, Li W, Fu D, Lu Y, Chen J. VSIG4 is highly expressed and correlated with poor prognosis of high-grade glioma patients. Am J Transl Res 2015;7(6):1172–1180.Byun J, Jeong D, Choi I, Lee D, Kang M, Jung K, Jeon Y, Kim Y, Jung E, Lee K, Sung M, Kim K. The significance of VSIG4 expression in ovarian cancer. Int J Gynecol Cancer 2017;27(5):872–878.Ethics ApprovalAll legal and ethical requirements were met with regards to the humane treatment of animals described in the study. The animal study was conducted in compliance with CRL IACUC under IACUC No. I033.

scholarly journals In Vitro and In Vivo Phagocytic Ability of Mouse B-1 Cells

2010 ◽  
Vol 2 ◽  
pp. III.S6156 ◽  
Author(s):  
RR Novaes E Brito ◽  
BA Cortez ◽  
GM Machado-Santelli ◽  
P Xander ◽  
BH De Lorenzo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
B Cells ◽  
Peritoneal Cavity ◽  
Mononuclear Phagocyte ◽  
Phagocytic Cells ◽  
Phagocytic Ability ◽  
Escherichia Coli Bacteria ◽  
Pathogen Clearance

B-1 cells are a peculiar subpopulation of B cells found in the peritoneal and pleural cavities in mice. These cells are typically IgM+ and CD11b+. B-1 cells are able to migrate from the peritoneal cavity to non-specific inflammatory sites in mice. In addition, they can differentiate into mononuclear phagocyte-like cells in vitro; however, it is still unknown whether B-1 cells are capable of performing phagocytosis in vivo. Here we further characterized B-1 cells as phagocytes in vitro, and we investigated their ability to phagocytose apoptotic cells and bacteria in vivo. Our results demonstrate that B-1 phagocytes are able to uptake apoptotic thymocytes and Escherichia coli bacteria, both in vitro and in vivo. These findings indicate that along with macrophages, B-1 phagocytic cells might play a role in fundamental processes such as tissue remodeling, resolution of inflammation and pathogen clearance.

scholarly journals In vitro and in vivo analyses of co-infections with peste des petits ruminants and capripox vaccine strains

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Dajun Zhang ◽  
Bo Yang ◽  
Ting Zhang ◽  
Xijuan Shi ◽  
Chaochao Shen ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Quantitative Pcr ◽  
Small Ruminants ◽  
Infection Model ◽  
Peste Des Petits Ruminants ◽  
Immune Effect ◽  
Tnf Α ◽  
Antibody Levels

Abstract Background Peste des petits ruminants (PPR) and goat pox (GTP) are two devastating animal epidemic diseases that affect small ruminants. Vaccination is one of the most important measures to prevent and control these two severe infectious diseases. Methods In this study, we vaccinated sheep with PPR and POX vaccines to compare the changes in the antibody levels between animals vaccinated with PPRV and POX vaccines alone and those co-infected with both vaccines simultaneously. The cell infection model was used to explore the interference mechanism between the vaccines in vitro. The antibody levels were detected with the commercial ELISA kit. The Real-time Quantitative PCR fluorescent quantitative PCR method was employed to detect the viral load changes and cytokines expression after the infection. Results The concurrent immunization of GTP and PPR vaccine enhanced the PPR vaccine's immune effect but inhibited the immune effect of the GTP vaccine. After the infection, GTP and PPR vaccine strains caused cytopathic effect; co-infection with GTP and PPR vaccine strains inhibited the replication of PPR vaccine strains; co-infection with GTP and PPR vaccine strains enhanced the replication of GTP vaccine strains. Moreover, virus mixed infection enhanced the mRNA expressions of TNF-α, IL-1β, IL-6, IL-10, IFN-α, and IFN-β by 2–170 times. GTP vaccine strains infection alone can enhanced the mRNA expression of IL-1β, TNF-α, IL-6, IL-10, while the expression of IFN-α mRNA is inhibited. PPR vaccine strains alone can enhanced the mRNA expression of IFN-α, IFN-β, TNF-α, and has little effect the mRNA expression of IL-1β, IL-6 and IL-10. The results showed that GTP and PPR vaccine used simultaneously in sheep enhanced the PPR vaccine's immune effect but inhibited the immune effect of the GTP vaccine in vivo. Furthermore, an infection of GTP and PPR vaccine strains caused significant cell lesions in vitro; co-infection with GTP + PPR vaccine strains inhibited the replication of PPR vaccine strains, while the co-infection of GTP followed by PPR infection enhanced the replication of GTP vaccine strains. Moreover, virus infection enhanced the expressions of TNF-α, IL-1β, IL-6, IL-10, IFN-α, and IFN-β. Conclusions Peste des petits ruminants and capripox vaccine strains interfere with each other in vivo and vitro.

scholarly journals Myeloid 12/15-LOX regulates B cell numbers and innate immune antibody levels in vivo

2017 ◽  
Vol 2 ◽  
pp. 1 ◽  
Author(s):  
Sarah N. Lauder ◽  
Victoria J Tyrrell ◽  
Keith Allen-Redpath ◽  
Maceler Aldrovandi ◽  
David Gray ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Function ◽  
Inflammatory Diseases ◽  
Innate Immune ◽  
Cell Phenotype ◽  
Cell Numbers ◽  
Antibody Levels ◽  
Immune Antibody

Background: The myeloid enzyme 12/15-lipoxygenase (LOX), which generates bioactive oxidized lipids, has been implicated in numerous inflammatory diseases, with several studies demonstrating an improvement in pathology in mice lacking the enzyme. However, the ability of 12/15-LOX to directly regulate B cell function has not been studied.Methods: The influence of 12/15-LOX on B cell phenotype and function, and IgM generation, was compared using wildtype (WT) and 12/15-LOX (Alox15-/-) deficient mice. The proliferative and functional capacity of splenic CD19+B cells was measuredin vitroin response to various toll-like receptor agonists.Results: WT andAlox15-/-displayed comparable responses. Howeverin vivo, splenic B cell numbers were significantly elevated inAlox15-/-mice with a corresponding elevation in titres of total IgM in lung, gut and serum, and lower serum IgM directed against the 12/15-LOX product, 12-hydroxyeicosatetraenoic acid-phosphatidylethanolamine (HETE-PE).Discussion: Myeloid 12/15-LOX can regulate B cell numbers and innate immune antibody levelsin vivo, potentially contributing to its ability to regulate inflammatory disease. Furthermore, the alterations seen in 12/15-LOX deficiency likely result from changes in the equilibrium of the immune system that develop from birth. Further studies in disease models are warranted to elucidate the contribution of 12/15-LOX mediated alterations in B cell numbers and innate immune antibody generation to driving inflammationin vivo.

scholarly journals Leptin signaling impairs macrophage defenses against Salmonella Typhimurium

2019 ◽  
Vol 116 (33) ◽  
pp. 16551-16560 ◽  
Author(s):  
Julia Fischer ◽  
Saray Gutièrrez ◽  
Raja Ganesan ◽  
Chiara Calabrese ◽  
Rajeev Ranjan ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Bacterial Infections ◽  
Leptin Receptor ◽  
Gram Negative ◽  
Leptin Signaling ◽  
Therapeutic Implications ◽  
Phosphorylated Akt ◽  
Pathogen Clearance

The dynamic interplay between metabolism and immune responses in health and disease, by which different immune cells impact on metabolic processes, are being increasingly appreciated. However, the potential of master regulators of metabolism to control innate immunity are less understood. Here, we studied the cross-talk between leptin signaling and macrophage function in the context of bacterial infections. We found that upon infection with Gram-negative pathogens, such as Salmonella Typhimurium, leptin receptor (Lepr) expression increased in both mouse and human macrophages. Unexpectedly, both genetic Lepr ablation in macrophages and global pharmacologic leptin antagonization augmented lysosomal functions, reduced S. Typhimurium burden, and diminished inflammation in vitro and in vivo. Mechanistically, we show that leptin induction activates the mTORC2/Akt pathway and subsequently down-regulates Phlpp1 phosphatase, allowing for phosphorylated Akt to impair lysosomal-mediated pathogen clearance. These data highlight a link between leptin signaling, the mTORC2/Phlpp1/Akt axis, and lysosomal activity in macrophages and have important therapeutic implications for modulating innate immunity to combat Gram-negative bacterial infections.

Sign in / Sign up

Export Citation Format

Share Document