scholarly journals Differential and sequential immunomodulatory role of neutrophils and Ly6Chi inflammatory monocytes during antiviral antibody therapy

2020 ◽  
Author(s):  
Jennifer Lambour ◽  
Mar Naranjo-Gomez ◽  
Myriam Boyer-Clavel ◽  
Mireia Pelegrin
Keyword(s):  
Immune Responses ◽  
Antibody Therapy ◽  
Myeloid Cell ◽  
Cell Types ◽  
Retroviral Infection ◽  
Antiviral Immune Response ◽  
Inflammatory Monocytes ◽  
Cytokines And Chemokines

AbstractAntiviral monoclonal antibodies (mAbs) can generate protective immunity through Fc-Fcγ Rs interactions. Using a mouse model of retroviral infection, we previously showed a crucial role for immune complexes (ICs) in the enhancement of T-cell responses through FcγR-mediated activation of dendritic cells (DCs). However, IC-FcγR interactions involve different cells of the immune system other than DCs such as neutrophils and monocytes. These two myeloid cell-types are innate effector cells rapidly recruited to sites of infection. In addition to being key cells to fight against invading pathogens, they are also endowed with immunomodulatory properties. While the role of DCs in enhancing antiviral immune responses upon mAb treatment has been addressed in several studies, the role of neutrophils and monocytes has been much less studied. Here we addressed how mAb therapy affects the functional activation of neutrophils and inflammatory monocytes in retrovirus-infected mice. We found that both cell-types activated in vitro by viral ICs secreted high levels of chemokines able to recruit monocytes and neutrophils themselves. Moreover, inflammatory cytokines potentiated chemokines and cytokines release by IC-activated cells and induced FcγRIV upregulation. Similarly, infection and mAb-treatment upregulated FcγRIV expression on neutrophils and inflammatory monocytes and enhanced their cytokines and chemokines secretion. Notably, upon antibody therapy neutrophils and inflammatory monocytes displayed distinct functional activation states and sequentially modulated the antiviral immune response through the secretion of Th1-type polarizing cytokines and chemokines. Our work provides novel findings on the immunomodulatory role of neutrophils and monocytes in the enhancement of immune responses upon antiviral mAb therapy.

scholarly journals Decoding the role of CBLB for innate immune responses regulating systemic dissemination during Non-Tuberculous Mycobacteria infection

2020 ◽  
Author(s):  
Srinivasu Mudalagiriyappa ◽  
Jaishree Sharma ◽  
Hazem F. M. Abdelaal ◽  
Thomas C. Kelly ◽  
Woosuk Choi ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Granulomatous Inflammation ◽  
Innate Immune ◽  
Dependent Manner ◽  
Innate Immune Responses ◽  
Inflammatory Monocytes ◽  
Cell Immunity

AbstractNon-Tuberculous Mycobacteria (NTM) are ubiquitous in nature, present in soil and water, and cause primary leading to disseminated infections in immunocompromised individuals. NTM infections are surging in recent years due to an increase in an immune-suppressed population, medical interventions, and patients with underlying lung diseases. Host regulators of innate immune responses, frontiers for controlling infections and dissemination, are poorly defined during NTM infections. Here, we describe the role of CBLB, an E3-ubiquitin ligase, for innate immune responses and disease progression in a mouse model of NTM infection under compromised T-cell immunity. We found that CBLB thwarted NTM growth and dissemination in a time- and infection route- dependent manner. Mechanistically, we uncovered defects in many innate immune cells in the absence of Cblb, including poor responses of NK cells, inflammatory monocytes, and conventional dendritic cells. Strikingly, Cblb-deficient macrophages were competent to control NTM growth in vitro. Histopathology suggested the lack of early formation of granulomatous inflammation in the absence of CBLB. Collectively, CBLB is essential to mount productive innate immune responses and help prevent the dissemination during an NTM infection under T-cell deficiency.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

scholarly journals Innate cell microenvironments in lymph nodes shape the generation of T cell responses during type I inflammation

2021 ◽  
Vol 6 (56) ◽  
pp. eabb9435
Author(s):  
Joseph M. Leal ◽  
Jessica Y. Huang ◽  
Karan Kohli ◽  
Caleb Stoltzfus ◽  
Miranda R. Lyons-Cohen ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Critical Role ◽  
Myeloid Cell ◽  
T Cell Responses ◽  
Type I ◽  
Cell Responses ◽  
Inflammatory Monocytes ◽  
Cell Effector

Microanatomical organization of innate immune cells within lymph nodes (LNs) is critical for the generation of adaptive responses. In particular, steady-state LN-resident dendritic cells (Res cDCs) are strategically localized to intercept lymph-draining antigens. Whether myeloid cell organization changes during inflammation and how that might affect the generation of immune responses are unknown. Here, we report that during type I, but not type II, inflammation after adjuvant immunization or viral infection, antigen-presenting Res cDCs undergo CCR7-dependent intranodal repositioning from the LN periphery into the T cell zone (TZ) to elicit T cell priming. Concurrently, inflammatory monocytes infiltrate the LNs via local blood vessels, enter the TZ, and cooperate with Res cDCs by providing polarizing cytokines to optimize T cell effector differentiation. Monocyte infiltration is nonuniform across LNs, generating distinct microenvironments with varied local innate cell composition. These spatial microdomains are associated with divergent early T cell effector programming, indicating that innate microenvironments within LNs play a critical role in regulating the quality and heterogeneity of T cell responses. Together, our findings reveal that dynamic modulation of innate cell microenvironments during type I inflammation leads to optimized generation of adaptive immune responses to vaccines and infections.

scholarly journals CCL2: An Important Mediator Between Tumor Cells and Host Cells in Tumor Microenvironment

2021 ◽  
Vol 11 ◽  
Author(s):  
Jiakang Jin ◽  
Jinti Lin ◽  
Ankai Xu ◽  
Jianan Lou ◽  
Chao Qian ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Cell Types ◽  
Host Cells ◽  
Specific Cell ◽  
Tumor Patients ◽  
Multiple Tumor ◽  
Inflammatory Monocytes ◽  
Immunosuppressive Cell ◽  
Tumor Types

Tumor microenvironment (TME) formation is a major cause of immunosuppression. The TME consists of a considerable number of macrophages and stromal cells that have been identified in multiple tumor types. CCL2 is the strongest chemoattractant involved in macrophage recruitment and a powerful initiator of inflammation. Evidence indicates that CCL2 can attract other host cells in the TME and direct their differentiation in cooperation with other cytokines. Overall, CCL2 has an unfavorable effect on prognosis in tumor patients because of the accumulation of immunosuppressive cell subtypes. However, there is also evidence demonstrating that CCL2 enhances the anti-tumor capability of specific cell types such as inflammatory monocytes and neutrophils. The inflammation state of the tumor seems to have a bi-lateral role in tumor progression. Here, we review works focusing on the interactions between cancer cells and host cells, and on the biological role of CCL2 in these processes.

scholarly journals From animal models to patients: the role of placental microRNAs, miR-210, miR-126, and miR-148a/152 in preeclampsia

2020 ◽  
Vol 134 (8) ◽  
pp. 1001-1025 ◽  
Author(s):  
Sonya Frazier ◽  
Martin W. McBride ◽  
Helen Mulvana ◽  
Delyth Graham
Keyword(s):  
Animal Models ◽  
Cell Types ◽  
Rodent Model ◽  
Hypertensive Disorder ◽  
Model Studies ◽  
Genetic Components ◽  
Immune Mediated ◽  
Hypertensive Disorder Of Pregnancy

Abstract Placental microRNAs (miRNAs) regulate the placental transcriptome and play a pathological role in preeclampsia (PE), a hypertensive disorder of pregnancy. Three PE rodent model studies explored the role of placental miRNAs, miR-210, miR-126, and miR-148/152 respectively, by examining expression of the miRNAs, their inducers, and potential gene targets. This review evaluates the role of miR-210, miR-126, and miR-148/152 in PE by comparing findings from the three rodent model studies with in vitro studies, other animal models, and preeclamptic patients to provide comprehensive insight into genetic components and pathological processes in the placenta contributing to PE. The majority of studies demonstrate miR-210 is upregulated in PE in part driven by HIF-1α and NF-κBp50, stimulated by hypoxia and/or immune-mediated processes. Elevated miR-210 may contribute to PE via inhibiting anti-inflammatory Th2-cytokines. Studies report an up- and downregulation of miR-126, arguably reflecting differences in expression between cell types and its multifunctional capacity. MiR-126 may play a pro-angiogenic role by mediating the PI3K-Akt pathway. Most studies report miR-148/152 family members are upregulated in PE. Evidence suggests they may inhibit DNA methylation of genes involved in metabolic and inflammatory pathways. Given the genetic heterogeneity of PE, it is unlikely that a single placental miRNA is a suitable therapeutic target for all patients. Investigating miRNAs in PE subtypes in patients and animal models may represent a more appropriate approach going forward. Developing methods for targeting placental miRNAs and specific placental cell types remains crucial for research seeking to target placental miRNAs as a novel treatment for PE.

scholarly journals The critical immunosuppressive effect of MDSC-derived exosomes in the tumor microenvironment

2020 ◽  
Author(s):  
Mohammad H. Rashid ◽  
Thaiz F. Borin ◽  
Roxan Ara ◽  
Raziye Piranlioglu ◽  
Bhagelu R. Achyut ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Cd8 T Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
Biological Macromolecules

AbstractMyeloid-derived suppressor cells (MDSCs) are an indispensable component of the tumor microenvironment (TME), and our perception regarding the role of MDSCs in tumor promotion is attaining extra layer of intricacy in every study. In conjunction with MDSC’s immunosuppressive and anti-tumor immunity, they candidly facilitate tumor growth, differentiation, and metastasis in several ways that yet to be explored. Alike any other cell types, MDSCs also release a tremendous amount of exosomes or nanovesicles of endosomal origin and partake in intercellular communications by dispatching biological macromolecules. There has not been any experimental study done to characterize the role of MDSCs derived exosomes (MDSC exo) in the modulation of TME. In this study, we isolated MDSC exo and demonstrated that they carry a significant amount of proteins that play an indispensable role in tumor growth, invasion, angiogenesis, and immunomodulation. We observed higher yield and more substantial immunosuppressive potential of exosomes isolated from MDSCs in the primary tumor area than those are in the spleen or bone marrow. Our in vitro data suggest that MDSC exo are capable of hyper activating or exhausting CD8 T-cells and induce reactive oxygen species production that elicits activation-induced cell death. We confirmed the depletion of CD8 T-cells in vivo by treating the mice with MDSC exo. We also observed a reduction in pro-inflammatory M1-macrophages in the spleen of those animals. Our results indicate that immunosuppressive and tumor-promoting functions of MDSC are also implemented by MDSC-derived exosomes which would open up a new avenue of MDSC research and MDSC-targeted therapy.

scholarly journals A75 ROLE OF LRRK2 IN INFLAMMATORY BOWEL DISEASE

2018 ◽  
Vol 1 (suppl_2) ◽  
pp. 118-118
Author(s):  
J Rocha ◽  
C Sun ◽  
M Glogauer ◽  
D Philpott
Keyword(s):  
Listeria Monocytogenes ◽  
Myeloid Cell ◽  
Mucosal Barrier ◽  
Ros Generation ◽  
Transwell Assay ◽  
Bacteria Growth ◽  
Tlr4 Ligand

Abstract Background Variants of the leucine-rich repeat kinase 2 (LRRK2) are associated with an increased susceptibility to Parkinson disease but also Crohn’s disease (CD). Aims The present research is designed to develop a comprehensive understanding of the role of LRRK2 in immune system modulation, and how dysfunction of this pathway may lead to the development of CD. Methods WT and LRRK2-deficient neutrophil were infected with Gram-positive Bacteria (Listeria monocytogenes-LM) in a gentamicin protection assays and colony-forming unit assessment will determine the competence of LRRK2 deficient cells for bacterial phagocytosis as well as killing capacity). To examine how LRRK2 is involved in the generation of ROS during the respiratory burst, we will first examine if neutrophil from LRRK2-KO mice have altered ROS generation upon infection with LM and addition of PMA. We evaluate in vitro the ability of neutrophils from LRRK2-KO versus WT mice to transmigrate in vitro in a transwell assay using fMLP as a chemattractant. Also, we investigate the peritoneal cells (by FACS analysis) after injection of different microbial stimuli including FK105 (NOD1 ligand), MDP (NOD2 ligand) and LPS (TLR4 ligand) and anti-cd3 model of ielitis. Results We found that LRRK2 KO mice have a defect in migration of neutrophils to the peritoneal cavity after injection of different microbial stimuli including FK10565 (NOD1 ligand), MDP (NOD2 ligand) and LPS (TLR4 ligand). Neutrophils from LRRK2 mice were compromised in their ability to transmigrate in vitro in a transwell assay using fMLP as a chemoattractant. Chemotaxis was also compromised. In parallel, we designed experiments to examine reactive oxygen species (ROS) produced in response to infection of myeloid cells with bacteria. Neutrophils from LRRK2 KO mice infected with Listeria monocytogenes were less able to restrict bacteria growth compared to WT cells. Consistent with these findings, cells from LRRK2 KO mice produced lower levels of ROS following bacterial infection. In order to determine whether myeloid cell migration is compromised in vivo during inflammation, we performed experiments in WT and KO mice looking at different models of ileitis/colitis. Conclusions With this work we will further characterize the role of LRRK2 in intestinal homeostasis and mucosal barrier maintenance, including how its deficiency may predispose an individual to developing CD. Funding Agencies CAG, CIHR

scholarly journals Revisiting the role of IRF3 in inflammation and immunity by conditional and specifically targeted gene ablation in mice

2018 ◽  
Vol 115 (20) ◽  
pp. 5253-5258 ◽  
Author(s):  
Hideyuki Yanai ◽  
Shiho Chiba ◽  
Sho Hangai ◽  
Kohei Kometani ◽  
Asuka Inoue ◽  
...  
Keyword(s):  
Immune Cell ◽  
Cell Types ◽  
Type I ◽  
Type I Ifn ◽  
Cell Type ◽  
Gene Ablation ◽  
Cell Type Specific

IFN regulatory factor 3 (IRF3) is a transcription regulator of cellular responses in many cell types that is known to be essential for innate immunity. To confirm IRF3’s broad role in immunity and to more fully discern its role in various cellular subsets, we engineered Irf3-floxed mice to allow for the cell type-specific ablation of Irf3. Analysis of these mice confirmed the general requirement of IRF3 for the evocation of type I IFN responses in vitro and in vivo. Furthermore, immune cell ontogeny and frequencies of immune cell types were unaffected when Irf3 was selectively inactivated in either T cells or B cells in the mice. Interestingly, in a model of lipopolysaccharide-induced septic shock, selective Irf3 deficiency in myeloid cells led to reduced levels of type I IFN in the sera and increased survival of these mice, indicating the myeloid-specific, pathogenic role of the Toll-like receptor 4–IRF3 type I IFN axis in this model of sepsis. Thus, Irf3-floxed mice can serve as useful tool for further exploring the cell type-specific functions of this transcription factor.

Abstract O.16: Comprehensive Genotyping Of The FCGR2/3 Locus Reveals A Novel Association Of FCGR2C-ORF With Susceptibility To Kawasaki Disease

Circulation ◽  
2015 ◽  
Vol 131 (suppl_2) ◽  
Author(s):  
Taco W Kuijpers ◽  
Carline E Tacke ◽  
Sietse Q Nagelkerke ◽  
Willemijn B Breunis ◽  
Long T Hoang ◽  
...  
Keyword(s):  
Kawasaki Disease ◽  
Myeloid Cell ◽  
Cell Types ◽  
Copy Number Variations ◽  
Nucleotide Polymorphisms ◽  
Homologous Genes ◽  
Genes Encoding ◽  
Novel Association ◽  
Family Based

The human FCGR2/3 locus contains highly homologous genes encoding the five major receptors for IgG (Fc-gamma receptors, FcγRs). In two prior GWAS on Kawasaki disease (KD), a SNP in FCGR2A (131H>R; rs1801274) was identified to be associated with disease susceptibility. However, the FCGR2/3 locus contains multiple single nucleotide polymorphisms (SNPs) and copy number variations (CNVs), which were not covered by the detection platforms used in the GWAS. In this study we therefore focused on further fine-mapping of this locus to investigate the association of the different genetic variations with KD susceptibility. A highly accurate and validated multiplex ligation-dependent probe amplification (MLPA) assay was used to analyze all functionally relevant SNPs and CNVs within this locus. In a genetic association study involving case-control and family-based testing with 1028 patients with KD, the previous finding of FCGR2A-131H as a susceptibility marker for KD was confirmed (OR 1.16; 95%CI 1.08-1.32, meta-P = 0.01). In addition, we found a novel significant association of the FCGR2C-ORF haplotype with susceptibility to KD (OR 1.34; 95% confidence interval 1.11-1.62, meta-P = 0.003). FCGR2C-ORF leads to the expression of an extra, functionally activating FcγR (i.e. FcγRIIc) on myeloid cell types and NK cells. Being absent in Asian individuals, the FCGR2C-ORF haplotype only contributed to KD susceptibility in European subjects, independent of the established association with FCGR2A-H131R. We did not find any significant association of CNV of the locus with susceptibility to KD. Our data point to an important role of the activating FcγRs in KD pathology. We hypothesize that the identified functional SNPs might alter the balance between the activating and inhibitory FcγRs leading to unbalanced inflammation and KD.

Sign in / Sign up

Export Citation Format

Share Document