scholarly journals Innate Immune Defenses in Human Tuberculosis: An Overview of the Interactions betweenMycobacterium tuberculosisand Innate Immune Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Jonathan Kevin Sia ◽  
Maria Georgieva ◽  
Jyothi Rengarajan
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Immune Cells ◽  
Public Health Problem ◽  
Human Infection ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Global Public Health ◽  
Bacterial Replication ◽  
Inflammatory Milieu

Tuberculosis (TB) remains a serious global public health problem that results in up to 2 million deaths each year. TB is caused by the human pathogen,Mycobacterium tuberculosis(Mtb), which infects primarily innate immune cells patrolling the lung. Innate immune cells serve as barometers of the immune response against Mtb infection by determining the inflammatory milieu in the lungs and promoting the generation of adaptive immune responses. However, innate immune cells are also potential niches for bacterial replication and are readily manipulated by Mtb. Our understanding of the early interactions between Mtb and innate immune cells is limited, especially in the context of human infection. This review will focus on Mtb interactions with human macrophages, dendritic cells, neutrophils, and NK cells and detail evidence that Mtb modulation of these cells negatively impacts Mtb-specific immune responses. Furthermore, this review will emphasize important innate immune pathways uncovered through human immunogenetic studies. Insights into the human innate immune response to Mtb infection are necessary for providing a rational basis for the augmentation of immune responses against Mtb infection, especially with respect to the generation of effective anti-TB immunotherapeutics and vaccines.

scholarly journals Helminth Infections: Recognition and Modulation of the Immune Response by Innate Immune Cells

2018 ◽  
Vol 9 ◽  
Author(s):  
Claudia Cristina Motran ◽  
Leonardo Silvane ◽  
Laura Silvina Chiapello ◽  
Martin Gustavo Theumer ◽  
Laura Fernanda Ambrosio ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Helminth Infections

scholarly journals Natural Killer Dendritic Cells Enhance Immune Responses Elicited byα-Galactosylceramide-Stimulated Natural Killer T Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Sung Won Lee ◽  
Hyun Jung Park ◽  
Nayoung Kim ◽  
Seokmann Hong
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Natural Killer ◽  
Immune Cells ◽  
Tumor Antigens ◽  
Nkt Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Natural Killer T

Natural killer dendritic cells (NKDCs) possess potent anti-tumor activity, but the cellular effect of NKDC interactions with other innate immune cells is unclear. In this study, we demonstrate that the interaction of NKDCs and natural killer T (NKT) cells is required for the anti-tumor immune responses that are elicited byα-galactosylceramide (α-GC) in mice. The rapid and strong expression of interferon-γby NKDCs afterα-GC stimulation was dependent on NKT cells. Various NK and DC molecular markers and cytotoxic molecules were up-regulated followingα-GC administration. This up-regulation could improve NKDC presentation of tumor antigens and increase cytotoxicity against tumor cells. NKDCs were required for the stimulation of DCs, NK cells, and NKT cells. The strong anti-tumor immune responses elicited byα-GC may be due to the down-regulation of regulatory T cells. Furthermore, the depletion of NKDCs dampened the tumor clearance mediated byα-GC-stimulated NKT cellsin vivo. Taken together, these results indicate that complex interactions of innate immune cells might be required to achieve optimal anti-tumor immune responses during the early stages of tumorigenesis.

scholarly journals Interfering with MIF-CD74 signalling on macrophages and dendritic cells with a peptide-based approach restores the immune response against metastatic melanoma

2018 ◽  
Author(s):  
Carlos R. Figueiredo ◽  
Ricardo A. Azevedo ◽  
Sasha Mousdell ◽  
Pedro T. Resende-Lara ◽  
Lucy Ireland ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Metastatic Melanoma ◽  
Immune Cells ◽  
Tumour Microenvironment ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Adaptive Immune Cells ◽  
Cancer Immunotherapies

ABSTRACTMounting an effective immune response against cancer requires the activation of innate and adaptive immune cells. Metastatic melanoma is the most aggressive form of skin cancer. Immunotherapies that boost the activity of effector T cells have shown a remarkable success in melanoma treatment. Patients, however, can develop resistance to such therapies by mechanisms that include the establishment of an immune suppressive tumour microenvironment. Understanding how metastatic melanoma cells suppress the immune system is vital to develop effective immunotherapies against this disease. In this study, we find that the innate immune cells, macrophages and dendritic cells are suppressed in metastatic melanoma. The Ig-CDR-based peptide C36L1 is able to restore macrophages and dendritic cells’ immunogenic functions and to inhibit metastatic growth in vivo. Mechanistically, we found that C36L1 interferes with the MIF-CD74 tumour-innate immune cells immunosuppressive signalling pathway and thereby restores an effective anti-tumour immune response. C36L1 directly binds to CD74 on macrophages and dendritic cells, disturbing CD74 structural dynamics and inhibiting MIF signalling through CD74. Our findings suggest that interfering with MIF-CD74 immunosuppressive signalling in macrophages and dendritic cells using peptide-based immunotherapy can restore the anti-tumour immune response in metastatic melanoma. Our study provides the rationale for further development of peptide-based therapies to restore the anti-tumour immune response.

scholarly journals The Role of Syk/CARD9-Coupled C-Type Lectin Receptors in Immunity toMycobacterium tuberculosisInfections

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Mohlopheni Jackson Marakalala ◽  
Lisa M. Graham ◽  
Gordon D. Brown
Keyword(s):  
Immune Response ◽  
Pattern Recognition ◽  
Mycobacterium Tuberculosis ◽  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Lectin Receptors ◽  
Molecular Patterns

There is increasing interest in understanding the mechanisms underlying the interactions that occur betweenMycobacterium tuberculosisand host innate immune cells. These cells express pattern recognition receptors (PRRs) which recognise mycobacterial pathogen-associated molecular patterns (PAMPs) and which can influence the host immune response to the infection. Although many of the PRRs appear to be redundant in the control ofM. tuberculosisinfectionin vivo, recent discoveries have revealed a key, nonredundant, role of the Syk/CARD9 signalling pathway in antimycobacterial immunity. Here we review these discoveries, as well as recent data investigating the role of the Syk/CARD9-coupled PRRs that have been implicated in mycobacterial recognition, including Dectin-1 and Mincle.

scholarly journals The Life Cycle Stages of Pneumocystis murina Have Opposing Effects on the Immune Response to This Opportunistic Fungal Pathogen

2016 ◽  
Vol 84 (11) ◽  
pp. 3195-3205 ◽  
Author(s):  
Heather M. Evans ◽  
Grady L. Bryant ◽  
Beth A. Garvy
Keyword(s):  
Cell Wall ◽  
Life Cycle ◽  
Immune Responses ◽  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Content Type ◽  
Life Cycle Stages ◽  
Ifn Γ

The cell wall β-glucans of Pneumocystis cysts have been shown to stimulate immune responses in lung epithelial cells, dendritic cells, and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with these innate immune cells. Here we report differences in the responses of both neonatal and adult mice to the trophic and cystic life cycle stages of Pneumocystis murina . The adult and neonatal immune responses to infection with Pneumocystis murina trophic forms were less robust than the responses to infection with a physiologically normal mixture of cysts and trophic forms. Cysts promoted the recruitment of nonresident innate immune cells and T and B cells into the lungs. Cysts, but not trophic forms, stimulated increased concentrations of the cytokine gamma interferon (IFN-γ) in the alveolar spaces and an increase in the percentage of CD4 + T cells that produce IFN-γ. In vitro , bone marrow-derived dendritic cells (BMDCs) stimulated with cysts produced the proinflammatory cytokines interleukin 1β (IL-1β) and IL-6. In contrast, trophic forms suppressed antigen presentation to CD4 + T cells, as well as the β-glucan-, lipoteichoic acid (LTA)-, and lipopolysaccharide (LPS)-induced production of interleukin 1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) by BMDCs. The negative effects of trophic forms were not due to ligation of mannose receptor. Our results indicate that optimal innate and adaptive immune responses to Pneumocystis species are dependent on stimulation with the cyst life cycle stage. Conversely, trophic forms suppress β-glucan-induced proinflammatory responses in vitro , suggesting that the trophic forms dampen cyst-induced inflammation in vivo .

scholarly journals Species-Specific Endotoxin Stimulus Determines Toll-Like Receptor 4- and Caspase 11-Mediated Pathway Activation Characteristics

mSystems ◽  
2021 ◽  
Author(s):  
Orna Ernst ◽  
Mohd M. Khan ◽  
Benjamin L. Oyler ◽  
Sung Hwan Yoon ◽  
Jing Sun ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Surface ◽  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Pathway Activation ◽  
Specific Receptors ◽  
Species Specific

Macrophages and monocytes are innate immune cells playing an important role in orchestrating the initial innate immune response to bacterial infection and the tissue damage. This response is facilitated by specific receptors on the cell surface and intracellularly.

scholarly journals Differential Regulation of Macrophage Interleukin-1 (IL-1), IL-12, and CD80-CD86 by Two Bacterial Toxins

1999 ◽  
Vol 67 (10) ◽  
pp. 5275-5281 ◽  
Author(s):  
Dennis L. Foss ◽  
Michael J. Zilliox ◽  
Michael P. Murtaugh
Keyword(s):  
Immune Response ◽  
Immune Cells ◽  
Interleukin 1 ◽  
Bacterial Toxins ◽  
Innate Immune ◽  
Interleukin 12 ◽  
Innate Immune Cells ◽  
Vaccine Adjuvants ◽  
Qualitative Nature ◽  
Ifn Γ

ABSTRACT The ability of innate immune cells to differentially respond to various bacterial components provides a mechanism by which the acquired immune response may be tailored to specific pathogens. The response of innate immune cells to bacterial components provides regulatory signals to cognate immune cells. These signals include secreted cytokines and costimulatory molecules, and to a large extent they determine the quantitative and qualitative nature of the immune response. In order to determine if innate immune cells can differentially respond to bacterial components, we compared the responses of macrophages to two bacterially derived molecules, cholera toxin (CT) and lipopolysaccharide (LPS). We found that CT and LPS differentially regulated the expression of interleukin-12 (IL-12) and CD80-CD86 but not that of IL-1β. LPS and CT each induced IL-1β expression in macrophages, while only LPS induced IL-12 and only CT induced CD80-CD86. These differences were markedly potentiated in gamma interferon (IFN-γ)-treated macrophages, in which LPS potently induced IL-12 and CD80-CD86 expression. In contrast, IFN-γ treatment had no effect on the expression of IL-1β. These results define a molecular basis for the differential pathogenicities of bacterial toxins and are relevant to the design of vaccine adjuvants able to selectively induce desired types of immunity.

Latest Advances in Small Molecule TLR 7/8 Agonist Drug Research

2019 ◽  
Vol 19 (24) ◽  
pp. 2228-2238 ◽  
Author(s):  
David C. McGowan
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Small Molecule ◽  
Immune Cells ◽  
Drug Research ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Small Molecule Activation ◽  
Evolutionarily Conserved ◽  
Recent Developments

Toll-like receptors (TLRs) 7 and 8 play an important role in the activation of innate immune cells in mammals. These evolutionarily conserved receptors serve as important sentinels in response to infection. Activation of TLRs 7 and 8 triggers induction of a Th1 type innate immune response. The emergence of new structural and small molecule information generated in the last decade has contributed enormously to our understanding of this highly sophisticated process of innate immunity signaling. This review will focus on recent developments in the small molecule activation of TLR 7 and 8.

Sign in / Sign up

Export Citation Format

Share Document