scholarly journals Environment impacts innate immune ontogeny

2016 ◽  
Vol 23 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Mathieu Garand ◽  
Bing Cai ◽  
Tobias R Kollmann

Susceptibility to infection and response to vaccination differ between populations and as a function of age. The underlying mechanisms for this age- and population-dependent variation are not known. Specifically, it is unclear if these variations are due to differences in genetically encoded host programs or driven by environmental influences or a combination of both. To address the relationship between gene and environment regarding immune ontogeny, we determined the innate cytokine responses following PRR stimulation of blood mononuclear cells at birth, 1, and 2 yr of age in infants from Caucasian vs . Asian parents and were raised in the same city. At birth, we found that innate cytokine responses were significantly elevated in Asian compared with Caucasian infants. However, these differences waned and responses became more similar over the course of 1–2 yr of living in a similar environment. Our observations that innate response differences present at birth subsequently equalized rather than diverged suggest a key role for environmental effects common to both racial groups in shaping the innate immune responses early in life. Delineating the underlying environmental factors that modulate innate immune responses early in life could provide avenues for targeted beneficial immune modulation.

2019 ◽  
Vol 116 (50) ◽  
pp. 25106-25114 ◽  
Author(s):  
Wenqian Li ◽  
Jun Yan ◽  
Yan Yu

Receptors of innate immune cells function synergistically to detect pathogens and elicit appropriate immune responses. Many receptor pairs also appear “colocalized” on the membranes of phagosomes, the intracellular compartments for pathogen ingestion. However, the nature of the seemingly receptor colocalization and the role it plays in immune regulation are unclear, due to the inaccessibility of intracellular phagocytic receptors. Here, we report a geometric manipulation technique to directly probe the role of phagocytic receptor “colocalization” in innate immune regulation. Using particles with spatially patterned ligands as phagocytic targets, we can decouple the receptor pair, Dectin-1 and Toll-like receptor (TLR)2, to opposite sides on a single phagosome or bring them into nanoscale proximity without changing the overall membrane composition. We show that Dectin-1 enhances immune responses triggered predominantly by TLR2 when their centroid-to-centroid proximity is <500 nm, but this signaling synergy diminishes upon receptor segregation beyond this threshold distance. Our results demonstrate that nanoscale proximity, not necessarily colocalization, between Dectin-1 and TLR2 is required for their synergistic regulation of macrophage immune responses. This study elucidates the relationship between the spatial organization of phagocytic receptors and innate immune responses. It showcases a technique that allows spatial manipulation of receptors and their signal cross-talk on phagosomes inside living cells.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Hang Yang ◽  
Tony N. Marion ◽  
Yi Liu ◽  
Lingshu Zhang ◽  
Xue Cao ◽  
...  

Nanotechnology has become a novel subject with impact in many research and technology areas. Nanoparticles (NPs), as a key component in nanotechnology, are widely used in many areas such as optical, magnetic, electrical, and mechanical engineering. The biomedical and pharmaceutical industries have embraced NPs as a viable drug delivery modality. As such, the potential for NP-induced cytotoxicity has emerged as a major concern for NP drug delivery systems. Thus, it is important to understand how NPs affect the innate immune system. As the most abundant myeloid cell type in innate immune responses, neutrophils are critical for concerns about potentially toxic side effects of NPs. When activated by innate immune stimuli, neutrophils may initiate NETosis to release neutrophil extracellular traps (NETs). Herein, we have reviewed the relationship between NPs and the induction of NETosis and release of NETs.


Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2060
Author(s):  
Yu Zhang ◽  
Shuaiyin Chen ◽  
Yuefei Jin ◽  
Wangquan Ji ◽  
Weiguo Zhang ◽  
...  

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a member of the Coronaviridae family, which is responsible for the COVID-19 pandemic followed by unprecedented global societal and economic disruptive impact. The innate immune system is the body’s first line of defense against invading pathogens and is induced by a variety of cellular receptors that sense viral components. However, various strategies are exploited by SARS-CoV-2 to disrupt the antiviral innate immune responses. Innate immune dysfunction is characterized by the weak generation of type I interferons (IFNs) and the hypersecretion of pro-inflammatory cytokines, leading to mortality and organ injury in patients with COVID-19. This review summarizes the existing understanding of the mutual effects between SARS-CoV-2 and the type I IFN (IFN-α/β) responses, emphasizing the relationship between host innate immune signaling and viral proteases with an insight on tackling potential therapeutic targets.


Parasitology ◽  
2019 ◽  
Vol 147 (4) ◽  
pp. 465-470
Author(s):  
Lisa J. Ioannidis ◽  
Emily Eriksson ◽  
Diana S. Hansen

AbstractThe CXCR3 chemokine CXCL10 or IFN-γ inducible protein 10 (IP-10) has been identified as an important biomarker of cerebral malaria (CM) mortality in children. Studies in mouse malaria infection models have shown that CXCL10 blockade alleviates brain intravascular inflammation and protects infected mice from CM. Despite the key role that CXCL10 plays in the development of CM, the leucocytic sources of CXCL10 in response to human malaria are not known. Here we investigated CXCL10 responses to Plasmodium falciparum in peripheral blood mononuclear cells (PBMCs). We found that PBMCs from malaria-unexposed donors produce CXCL10 in response to P. falciparum and that this response is IFN-γ-dependent. Moreover, CD14+ monocytes were identified as the main leucocytic sources of CXCL10 in peripheral blood, suggesting an important role for innate immune responses in the activation of this pathway involved in the development of symptomatic malaria.


Author(s):  
Ayesha J Verrall ◽  
Marion Schneider ◽  
Bachti Alisjahbana ◽  
Lika Apriani ◽  
Arjan van Laarhoven ◽  
...  

AbstractBackgroundA proportion of tuberculosis (TB) case contacts do not become infected, even when heavily exposed. We studied the innate immune responses of TB case contacts to understand their role in protection against infection with Mycobacterium tuberculosis, termed “early clearance.”MethodsIndonesian household contacts of TB cases were tested for interferon-γ release assay (IGRA) conversion between baseline and 14 weeks post recruitment. Blood cell populations and ex vivo innate whole blood cytokine responses were measured at baseline and, in a subgroup, flow cytometry was performed at weeks 2 and 14. Immunological characteristics were measured for early clearers, defined as a persistently negative IGRA at 3 months, and converters, whose IGRA converted from negative to positive.ResultsAmong 1347 case contacts, 317 were early clearers and 116 were converters. Flow cytometry showed a resolving innate cellular response from 2 to 14 weeks in persistently IGRA-negative contacts but not converters. There were no differences in cytokine responses to mycobacterial stimuli, but compared to converters, persistently IGRA-negative contacts produced more proinflammatory cytokines following heterologous stimulation with Escherichia coli and Streptococcus pneumoniae.ConclusionsEarly clearance of M. tuberculosis is associated with enhanced heterologous innate immune responses similar to those activated during induction of trained immunity.


2021 ◽  
pp. 1-7
Author(s):  
Hyago Passe Pereira ◽  
Lucas Lima Verardo ◽  
Mayara Morena Del Cambre Amaral Weller ◽  
Ana Paula Sbardella ◽  
Danísio Prado Munari ◽  
...  

Abstract This study aimed to obtain a better understanding of the regulatory genes and molecules involved in the development of mastitis. For this purpose, the transcription factors (TF) and MicroRNAs (miRNA) related to differentially expressed genes previously found in extracorporeal udders infected with Streptococcus agalactiae were investigated. The Gene-TF network highlighted LOC515333, SAA3, CD14, NFKBIA, APOC2 and LOC100335608 and genes that encode the most representative transcription factors STAT3, PPARG, EGR1 and NFKB1 for infected udders. In addition, it was possible to highlight, through the analysis of the gene-miRNA network, genes that could be post-transcriptionally regulated by miRNAs, such as the relationship between the CCL5 gene and the miRNA bta-miR-363. Overall, our data demonstrated genes and regulatory elements (TF and miRNA) that can play an important role in mastitis resistance. The results provide new insights into the first functional pathways and the network of genes that orchestrate the innate immune responses to infection by Streptococcus agalactiae. Our results will increase the general knowledge about the gene networks, transcription factors and miRNAs involved in fighting intramammary infection and maintaining tissue during infection and thus enable a better understanding of the pathophysiology of mastitis.


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