scholarly journals Innate immune signaling in the olfactory epithelium reduces odorant receptor levels: modeling transient smell loss in COVID-19 patients

2020 ◽  
Author(s):  
Steve Rodriguez ◽  
Luxiang Cao ◽  
Gregory T. Rickenbacher ◽  
Eric G. Benz ◽  
Colin Magdamo ◽  
...  
Keyword(s):  
Olfactory Epithelium ◽  
Odorant Receptor ◽  
Recovery Phase ◽  
Odor Discrimination ◽  
Olfactory Function ◽  
Receptor Expression ◽  
Odorant Receptors ◽  
Type I ◽  
Innate Immune Signaling ◽  
Leading Symptom

Post-infectious anosmias typically follow death of olfactory sensory neurons (OSNs) with a months-long recovery phase associated with parosmias. While profound anosmia is the leading symptom associated with COVID-19 infection, many patients regain olfactory function within days to weeks without distortions. Here, we demonstrate that sterile induction of anti-viral type I interferon signaling in the mouse olfactory epithelium is associated with diminished odor discrimination and reduced odor-evoked local field potentials. RNA levels of all class I, class II, and TAAR odorant receptors are markedly reduced in OSNs in a non-cell autonomous manner. We find that people infected with COVID-19 rate odors with lower intensities and have odor discrimination deficits relative to people that tested negative for COVID-19. Taken together, we propose that inflammatory-mediated loss of odorant receptor expression with preserved circuit integrity accounts for the profound anosmia and rapid recovery of olfactory function without parosmias caused by COVID-19.

scholarly journals Odor coding in the mammalian olfactory epithelium

2021 ◽  
Author(s):  
Smija M. Kurian ◽  
Rafaella G. Naressi ◽  
Diogo Manoel ◽  
Ann-Sophie Barwich ◽  
Bettina Malnic ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Olfactory Epithelium ◽  
New Technologies ◽  
Odorant Receptor ◽  
Olfactory Mucosa ◽  
Odorant Receptors ◽  
Odor Coding ◽  
New Era ◽  
Odor Detection ◽  
Receptor Interactions

AbstractNoses are extremely sophisticated chemical detectors allowing animals to use scents to interpret and navigate their environments. Odor detection starts with the activation of odorant receptors (ORs), expressed in mature olfactory sensory neurons (OSNs) populating the olfactory mucosa. Different odorants, or different concentrations of the same odorant, activate unique ensembles of ORs. This mechanism of combinatorial receptor coding provided a possible explanation as to why different odorants are perceived as having distinct odors. Aided by new technologies, several recent studies have found that antagonist interactions also play an important role in the formation of the combinatorial receptor code. These findings mark the start of a new era in the study of odorant-receptor interactions and add a new level of complexity to odor coding in mammals.

Laminar segregation of odorant receptor expression in the olfactory epithelium

1996 ◽  
Vol 284 (3) ◽  
pp. 347-354 ◽  
Author(s):  
Jörg Strotmann ◽  
Sidonie Konzelmann ◽  
Heinz Breer
Keyword(s):  
Olfactory Epithelium ◽  
Odorant Receptor ◽  
Receptor Expression

scholarly journals Odor Coding in the Mammalian Olfactory Epithelium

2020 ◽  
Author(s):  
Smija M. Kurian ◽  
Rafaella G. Naressi ◽  
Diogo Manoel ◽  
Ann-Sophie Barwich ◽  
Bettina Malnic ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Olfactory Epithelium ◽  
New Technologies ◽  
Odorant Receptor ◽  
Olfactory Mucosa ◽  
Odorant Receptors ◽  
Odor Coding ◽  
New Era ◽  
Odor Detection ◽  
Receptor Interactions

Noses are extremely sophisticated chemical detectors allowing animals to use scents to interpret and navigate their environments. Odor detection starts with the activation of odorant receptors (ORs), expressed in mature olfactory sensory neurons (OSNs) populating the olfactory mucosa. Different odorants, or different concentrations of the same odorant, activate unique ensembles of ORs. This mechanism of combinatorial receptor coding provided a possible explanation as to why different odorants are perceived as having distinct odors. Aided by new technologies, several recent studies have found that antagonist interactions also play an important role in the formation of the combinatorial receptor code. These findings mark the start of a new era in the study of odorant-receptor interactions and add a new level of complexity to odor coding in mammals.

Spatial segregation of odorant receptor expression in the mammalian olfactory epithelium

Cell ◽  
1993 ◽  
Vol 74 (2) ◽  
pp. 309-318 ◽  
Author(s):  
Robert Vassar ◽  
John Ngai ◽  
Richard Axel
Keyword(s):  
Olfactory Epithelium ◽  
Odorant Receptor ◽  
Spatial Segregation ◽  
Receptor Expression

scholarly journals MAVS: A Two-Sided CARD Mediating Antiviral Innate Immune Signaling and Regulating Immune Homeostasis

2021 ◽  
Vol 12 ◽  
Author(s):  
Yunqiang Chen ◽  
Yuheng Shi ◽  
Jing Wu ◽  
Nan Qi
Keyword(s):  
Signal Transduction ◽  
Innate Immune ◽  
Immune Homeostasis ◽  
Type I ◽  
Interferon Signaling ◽  
Immune Signaling ◽  
Post Translational Modifications ◽  
Innate Immune Signaling ◽  
Mitochondrial Antiviral Signaling ◽  
Mitochondrial Antiviral Signaling Protein

Mitochondrial antiviral signaling protein (MAVS) functions as a “switch” in the immune signal transduction against most RNA viruses. Upon viral infection, MAVS forms prion-like aggregates by receiving the cytosolic RNA sensor retinoic acid-inducible gene I-activated signaling and further activates/switches on the type I interferon signaling. While under resting state, MAVS is prevented from spontaneously aggregating to switch off the signal transduction and maintain immune homeostasis. Due to the dual role in antiviral signal transduction and immune homeostasis, MAVS has emerged as the central regulation target by both viruses and hosts. Recently, researchers show increasing interest in viral evasion strategies and immune homeostasis regulations targeting MAVS, especially focusing on the post-translational modifications of MAVS, such as ubiquitination and phosphorylation. This review summarizes the regulations of MAVS in antiviral innate immune signaling transduction and immune homeostasis maintenance.

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