A Missing Link: Engagements of Dendritic Cells in the Pathogenesis of SARS-CoV-2 Infections

Dendritic cells (DC) connect the innate and adaptive arms of the immune system and carry out numerous roles that are significant in the context of viral disease. Their functions include the control of inflammatory responses, the promotion of tolerance, cross-presentation, immune cell recruitment and the production of antiviral cytokines. Based primarily on the available literature that characterizes the behaviour of many DC subsets during Severe acute respiratory syndrome (SARS) and coronavirus disease 2019 (COVID-19), we speculated possible mechanisms through which DC could contribute to COVID-19 immune responses, such as dissemination of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to lymph nodes, mounting dysfunctional inteferon responses and T cell immunity in patients. We highlighted gaps of knowledge in our understanding of DC in COVID-19 pathogenesis and discussed current pre-clinical development of therapies for COVID-19.

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Non-Coding RNAs in COVID-19: Emerging Insights and Current Questions

Non-Coding RNA ◽

10.3390/ncrna7030054 ◽

2021 ◽

Vol 7 (3) ◽

pp. 54

Author(s):

Tobias Plowman ◽

Dimitris Lagos

Keyword(s):

Immune Response ◽

Severe Acute Respiratory Syndrome ◽

Immune Cell ◽

Cytokine Storm ◽

Cell Recruitment ◽

Vascular Dysregulation ◽

Virus Rna ◽

Growing Body ◽

Non Coding Rnas ◽

Immune Cell Recruitment

The highly infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as the causative agent of coronavirus disease 2019 (COVID-19) in late 2019, igniting an unprecedented pandemic. A mechanistic picture characterising the acute immunopathological disease in severe COVID-19 is developing. Non-coding RNAs (ncRNAs) constitute the transcribed but un-translated portion of the genome and, until recent decades, have been undiscovered or overlooked. A growing body of research continues to demonstrate their interconnected involvement in the immune response to SARS-CoV-2 and COVID-19 development by regulating several of its pathological hallmarks: cytokine storm syndrome, haemostatic alterations, immune cell recruitment, and vascular dysregulation. There is also keen interest in exploring the possibility of host–virus RNA–RNA and RNA–RBP interactions. Here, we discuss and evaluate evidence demonstrating the involvement of short and long ncRNAs in COVID-19 and use this information to propose hypotheses for future mechanistic and clinical studies.

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IL-6 trans-signaling regulates vascular endothelial laminin profile and inflammatory responses: Possible mechanism for immune cell recruitment during atherosclerosis?

Atherosclerosis ◽

10.1016/j.atherosclerosis.2021.06.175 ◽

2021 ◽

Vol 331 ◽

pp. e61

Author(s):

M.M. Zegeye ◽

A.K. Kumawat ◽

L. Matic ◽

M. Lengquist ◽

A. Hyderi ◽

...

Keyword(s):

Immune Cell ◽

Inflammatory Responses ◽

Vascular Endothelial ◽

Cell Recruitment ◽

Immune Cell Recruitment

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Comparative Analysis of Cytokine Expression in Oral Keratinocytes and THP-1 Macrophages in Response to the Most Prevalent Serotypes of Aggregatibacter actinomycetemcomitans

Microorganisms ◽

10.3390/microorganisms9030622 ◽

2021 ◽

Vol 9 (3) ◽

pp. 622

Author(s):

Daniel Betancur ◽

Camila Muñoz Grez ◽

Angel Oñate

Keyword(s):

Immune Responses ◽

Immune Cell ◽

Aggregatibacter Actinomycetemcomitans ◽

Chronic Inflammatory Disease ◽

Gram Negative Bacteria ◽

Oral Keratinocytes ◽

Cell Recruitment ◽

Tnf Α ◽

Serotype B ◽

Immune Cell Recruitment

Background: Periodontitis is a chronic inflammatory disease associated with a dysbiotic biofilm. Many pathogens have been related with its progression and severity, one of which is Aggregatibacter actinomycetemcomitans, a Gram-negative bacteria with seven serotypes (a–g) according with the structure of its LPS, with serotype b defined as the most virulent compared with the other serotypes. The aim of this study was to evaluate the response of oral keratinocytes and macrophages to A. actinomycetemcomitans. Methods: Oral keratinocytes (OKF6/TERT2) and macrophages (THP-1) were infected with A. actinomycetemcomitans serotypes a, b and c. The expression of IL-1β, IL-6, IL-8, IL-18, TNF-α, MMP-9, RANKL, TLR-2, TLR-4, TLR-6, thymic stromal lymphopoietin (TSLP), and ICAM-1 was evaluated by qPCR at 2 and 24 h after infection. Results: An increase in the expression of these molecules was induced by all serotypes at both times of infection, with macrophages showing higher levels of expression at 24 h compared to epithelial cells in which the highest levels were observed in the first hours after infection. Conclusions: Keratinocytes and macrophages contribute to the inflammation in periodontitis from the early stages of infection, producing the first waves of cytokines, acting as the first signal for professional immune cell recruitment and modulation of more specific immune responses.

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IL-17A Promotes Immune Cell Recruitment in Human Esophageal Cancers and the Infiltrating Dendritic Cells Represent a Positive Prognostic Marker for Patient Survival

Journal of Immunotherapy ◽

10.1097/cji.0b013e3182a802cf ◽

2013 ◽

Vol 36 (8) ◽

pp. 451-458 ◽

Cited By ~ 33

Author(s):

Lin Lu ◽

Ke Pan ◽

Hai-Xia Zheng ◽

Jian-Jun Li ◽

Hui-Juan Qiu ◽

...

Keyword(s):

Dendritic Cells ◽

Prognostic Marker ◽

Immune Cell ◽

Patient Survival ◽

Cell Recruitment ◽

Esophageal Cancers ◽

Immune Cell Recruitment

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Mycobacterium tuberculosis HN878 Infection Induces Human-Like B-Cell Follicles in Mice

The Journal of Infectious Diseases ◽

10.1093/infdis/jiz663 ◽

2019 ◽

Vol 221 (10) ◽

pp. 1636-1646 ◽

Cited By ~ 1

Author(s):

José Alberto Choreño-Parra ◽

Suhas Bobba ◽

Javier Rangel-Moreno ◽

Mushtaq Ahmed ◽

Smriti Mehra ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Immune Responses ◽

B Cell ◽

Spatial Organization ◽

Immune Cell ◽

Large Animal ◽

Cell Recruitment ◽

Large Animal Models ◽

Immune Parameters ◽

Immune Cell Recruitment

Abstract Specific spatial organization of granulomas within the lungs is crucial for protective anti-tuberculosis (TB) immune responses. However, only large animal models such as macaques are thought to reproduce the morphological hallmarks of human TB granulomas. In this study, we show that infection of mice with clinical “hypervirulent” Mycobacterium tuberculosis (Mtb) HN878 induces human-like granulomas composed of bacilli-loaded macrophages surrounded by lymphocytes and organized localization of germinal centers and B-cell follicles. Infection with laboratory-adapted Mtb H37Rv resulted in granulomas that are characterized by unorganized clusters of macrophages scattered between lymphocytes. An in-depth exploration of the functions of B cells within these follicles suggested diverse roles and the activation of signaling pathways associated with antigen presentation and immune cell recruitment. These findings support the use of clinical Mtb HN878 strain for infection in mice as an appropriate model to study immune parameters associated with human TB granulomas.

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