Mast Cell Disorder Support Network

Articles relating to COVID 19

Posts and articles from our official researcher Don Snyder

TGF-b1 Limits the Onset of Innate Lung Inflammation by Promoting Mast Cell–Derived IL-6

Kirthana Ganeshan, Laura K. Johnston, and Paul J. Bryce

"In addition to their established role in allergy, mast cells are being increasingly recognized for their roles in innate immune responses and in shaping the nature of the ensuing inflammatory response.
Indeed, our study demonstrated that Tregs and TGF-b1 actively increased mast cell–derived IL-6 and that this enhanced the development of Th17 cells and intestinal homeostasis in a food allergy model.

In vitro production of IL-6 by mast cells occurs rapidly upon LPS-driven activation and is independent of the degranulation response that underlies the established role of mast cells in IgE-mediated immediate hypersensitivity.

Although the physiological roles of mast cell–derived IL-6 remain largely unknown, recent studies showed that it is important in protection against Klebsiella pneumonia infection and in limiting tumor growth, implying a role in innate immune responses.

In conclusion, our findings describe a previously unappreciated process through which the magnitude of innate inflammation is regulated in the lung. Surprisingly, this occurs via two cytokines, TGF-b1 and IL-6, which have been characterized extensively for their deleterious effects in chronic inflammation. However, as we propose, the priming influence of TGF-b1on tissue resident mast cells serves to enhance IL-6 production upon LPS exposure, which drives the infiltrating neutrophil into apoptotic clearance."

Tryptase is involved in the development of early ventilator-induced pulmonary fibrosis in sepsis-induced lung injury

Jesús Villar, Nuria E Cabrera-Benítez,

"Most patients with sepsis and acute lung injury require mechanical ventilation to improve oxygenation and facilitate organ repair. Mast cells are important in response to infection and resolution of tissue injury. Since tryptase secreted from mast cells has been associated with tissue fibrosis, we hypothesized that tryptase would be involved in the early development of ventilator-induced pulmonary fibrosis in a clinically relevant model of sepsis-induced lung injury.

A feature of lungs in patients with fibrotic lung disease is the increased number of mast cells [16] and it has been suggested that mast cells may support the continuation of the fibroproliferative process in patients with ARDS [17] by release of mediators. The most abundant product of mast cells is tryptase, a serine protease with pleiotropic biological activities [18]. Tryptases consist of α-tryptase and β-tryptase [19]. β-tryptase is the main isoenzyme expressed in human lung. Tryptase upregulates the expression of cytokines [19] and vascular endothelial growth factor (VEGF).

The term ‘fibroproliferative’ has been conventionally applied only to ‘late-phase ARDS’, but pulmonary fibroproliferation can occur early in ARDS and is correlated with outcome [15,34]. Although in our animal model the exudative stage of acute lung injury and VILI is dominated by the presence of edema and inflammatory infiltrates [6], increased collagen was present in all lung samples at 18 h after CLP and increased further after 4 h of high-VT MV, confirming our previous results.

They also demonstrated that by inhibiting tryptase, lung injury was reduced while activating mast cells further aggravated lung damage.

Our experimental findings provide evidence for an association between acute lung injury, tryptase, PAR-2, and pulmonary fibrosis in VILI and sepsis-induced lung injury. Further studies are needed to fully address whether the attenuation or inhibition of tryptase and/or PAR-2 may offer a potential clinical therapeutic option in the setting of VILI and sepsis-induced ARDS.

Key messages

Changes in tryptase and collagen lung content during sepsis-induced acute lung injury are dependent on the mechanical ventilation strategy.

Increased expression of tryptase and collagen induced by alveolar overdistension may be important events contributing to the development of ventilator-induced pulmonary fibrosis.

Attenuation or inhibition of tryptase and/or PAR-2 may offer a potential clinical therapeutic option in the setting of VILI and sepsis-induced ARDS."

Where Are We At?? 3/17/2020

  1. NSAIDs (ibuprofen, asprin, etc) may infect be adverse for the viral infection

  2. Naproxen has some role in inhibition of the viral replication and inflammation.

  3. Sodium cromylgate, quercetin, and ketotifen all have positive action toward minimizing viral effects, infection, and reproduction.

Thanks to all the Masterminds that help dig out the research and post it for the family.

I have shared the info you helped pull together with the entire Ben’s Friends Community of 200,000 rare disease folks.

Hopefully we may help save someone’s Mom or Dad or Grandparents.

You make a difference with real science…

Quercetin as an Antiviral Agent Inhibits Influenza A Virus (IAV) Entry

Wenjiao Wu, Richan Li,

"The result revealed that quercetin reduced HA mRNA transcription in influenza-virus-infected cells in a dose-dependent manner (Figure 1C,D).
To further confirm that quercetin also impairs viral protein expressions, MDCK cells were infected with the influenza A/Puerto Rico/8/34 (H1N1) virus at 100 TCID50 in the presence of various concentrations of quercetin. At 24 h post-infection, cells were analyzed for virus nucleoprotein (NP) localization by an indirect immunofluorescence assay. As the data shown (Figure 2), quercetin showed significant inhibition on viral NP protein synthesis in a dose-dependent way in MDCK cells.

All the data above adequately illustrated quercetin could effectively inhibit influenza virus infections and inspired us to further detect the mechanism of quercetin inhibiting influenza virus infections.

In the initial study, we found that quercetin displayed antiviral activity against different influenza virus strains, including H1N1and H3N2, which impelled us to investigate the mechanism of its anti-influenza activity.

Surprisingly, we found that the inhibitory effect of quercetin was enhanced when the virus was pre-incubated with quercetin, or the cell was infected with the virus in the presence of quercetin. The time of the additional assay indicated that quercetin effectively inhibited virus infection when it was added during virus entry stage, while the inhibitory effects of other stages were less clear.

On the basis of the above results, we wondered whether quercetin targeted the virion or the cell.

Through three different modes of treatment, namely co-treatment, pre-treatment of cells and pre-treatment of virus, we found that quercetin targeted influenza viral particles instead of the host cell.

Our study demonstrates quercetin is a novel antiviral agent, which may be used as an effective, safe and affordable chemoprophylaxis or treatment of influenza infection. Importantly, quercetin targeting to the HA2 subunit of influenza hemagglutinin provides new insights for the development of a class of anti-influenza fusion inhibitors."

Mast Cell-Induced Lung Injury in Mice Infected with H5N1 Influenza Virus

(Effects of Ketotofin and Oseltamivir in reducing lung damage)

Yanxin Hu, Yi Jin,

In the present study, we investigated whether mast cells play a role in the initial process of influenza virus infection and what contributions mast cells make to the pathological consequences of influenza viruses.

We show that mast cells actively participate in the first-line immunological responses to infection.

Through release of tryptase, histamine, and gamma interferon (IFN-γ), mast cells could aggravate pathological injury of the infected tissues by directly inducing apoptosis or inflammatory cytokines and mediators.

To investigate whether mast cells were activated by H5N1 virus (A/chicken/Henan/1/2004) infection, we used the mast cell inhibitor ketotifen. Mice were given ketotifen (1 mg/kg body weight) once daily for 3 days by oral gavage, and all mice were challenged with 5 LD50 of H5N1 virus at 4 h after the first dose of ketotifen.

Remarkably, we found that ketotifen treatment significantly reduced the lung lesions (Fig. 3A).

Mice without ketotifen treatment showed severe bronchiolitis, peribronchiolitis, and bronchopneumonia, which were characterized by dropout and necrosis of mucous epithelial cells in the bronchioles; infiltration of various inflammatory cells, including lymphocytes, neutrophils, and plasmacytes near the small blood vessels; interstitial edema; thickening of the alveolar walls; and alveolar lumen flooding with dropout of alveolar cells, erythrocytes, and inflammatory cells in the lung.

In comparison, the lungs of the mice with ketotifen treatment demonstrated only mild pathological lesions, such as mild bronchiolitis, which was characterized by dropout and necrosis of mucous epithelial cells in the bronchioles and inflammatory cell infiltration around the bronchioles and small blood vessels.

Here, we found that inhibition of mast cell degranulation effectively protected mice from death after H5N1 infection, probably by reducing the lung lesions and by inhibition of apoptosis, which was evidenced by a decreased level of IFN-γ in ketotifen-treated groups.

The results suggest that the mast cell degranulation inhibitor is a potent antiviral agent against influenza virus. We found that a combination of ketotifen (10 mg/kg) and oseltamivir (10 mg/kg) protected 100% of the mice from death caused by H5N1 infection, which offers an alternative strategy for controlling a potential pandemic influenza outbreak.

The therapeutic effects of sodium cromoglycate against influenza A virus H5N1 in mice

Deping Han,

"Our previous study revealed that mast cells play roles in the pathogenesis of lung injury after H5N1 virus infection by producing proinflammatory mediators including tryptase, histamine, and interferon‐γ (IFN‐γ). In addition, the resulting lung injury was improved by treatment with ketotifen, which inhibits mast cell activation.19

Sodium cromoglycate (SCG) can inhibit degranulation and the release of histamine and inflammatory mediators from mast cells. It is used to treat allergic asthma, allergic rhinitis, small intestine ischemia/reperfusion, allergic conjunctivitis, and contact dermatitis;20, 21, 22, 23, 24 however, its role in the pathogenesis of H5N1 virus infection is unclear.

In this study, we investigated whether SCG has protective effects during the initial process of influenza virus infection and the possible mechanism behind any such effects.

We show that SCG can improve the mouse survival and respiratory pathological changes. Although viral replication was not inhibited, SCG could regulate the expressions of IL‐6, TNF‐α, TLR3, and TRIF to alleviate the pathological injury to the nose, trachea, and lungs by reducing the inflammatory response.

Analysis of the respiratory pathological changes after H5N1 infection revealed that there was significant inflammatory cell infiltration in H5N1 virus‐infected mice, whereas fewer pathological changes were observed in SCG‐treated mice.

This suggests that SCG could stabilize mast cells to reduce the release of cytokines and chemokines and alleviate inflammatory cell infiltration in the lungs.

These results further suggest that mast cells are involved in the pathogenesis of H5N1 virus infection and that preventing aberrant inflammation could protect the mice from mortality.

Previous studies reported that cytokine dysregulation contributed to the severity of influenza H5N1 virus infection.

In summary, SCG protected mice effectively from death after H5N1 infection by alleviating inflammatory injury via its function as an inhibitor of mast cell degranulation. These data provide a novel approach for combating highly pathogenic influenza virus infection."

Genome-wide gene expression profiling of human mast cells stimulated by IgE or FcεRI-aggregation reveals a complex network of genes involved in inflammatory responses

Ethanol Extract of Sanguisorbae Radix Inhibits Mast Cell Degranulation and Suppresses 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis-Like Skin Lesions

Genome-wide gene expression profiling of human mast cells stimulated by IgE or FceRI-aggregation reveals a complex network of genes involved in inflammatory responses


BACKGROUND: Mast cells are well established effectors of IgE-triggered allergic reactions and immune responses to parasitic infections. Recent studies indicate that mast cells may play roles in adaptive and innate immunity, suggesting an innovative view of the regulation of immune responses. Here, we profiled the transcriptome of human mast cells sensitized with IgE alone, or stimulated by FecµRI aggregation.

RESULTS: Our data show that among 8,793 genes examined, 559 genes are differentially regulated in stimulated mast cells when compared with resting/unstimulated mast cells. The major functional categories of upregulated genes include cytokines, chemokines, and other genes involved in innate and adaptive immune-responses. We observed the increased expression of over 63 gene-transcripts following IgE-sensitization alone. Our data was validated using Real-Time-PCR; ELISA and western blot. We confirmed that IgE alone does not trigger mast cell-immediate responses, such as calcium signals, degranulation or protein-phosphorylation.

CONCLUSION: This report represents a substantial advance in our understanding of the genome wide effects triggered by “passive sensitization” or active stimulation of human mast cells, supporting mast cells’ potential involvement in a wide range of inflammatory responses.

Which Species Transmit COVID-19 to Humans? We’re Still Not Sure.

OR “I Sure as Hell wouldn’t eat that thing Bubba, Put that crap back down in the road and lets go get us a Whataburger”

Preliminary modeling studies provide a shortlist of potential coronavirus intermediate host species.

Claire Jarvis Mar 16, 2020

When a new zoonotic outbreak occurs, scientists rush to trace the species the infection originated from. Often the infection jumps from its initial animal carrier to an intermediate host species, which then transmits the virus to humans. Identifying intermediate host species enable risk-mitigating public health policies to be implemented and gives researchers a better understanding of the disease evolution and pathogenesis.

SARS-CoV-2, the virus that causes COVID-19, belongs to the same family of viruses as SARS-CoV and MERS-CoV, which first circulated in bats before transmitting via intermediate hosts to humans. While SARS-CoV-2 is likely to have come to humans through a similar route, “we currently don’t have any evidence that there’s an intermediate host,” says William Karesh, the executive vice president for health and policy at EcoHealth Alliance, who notes that coronaviruses can directly transmit from bats to humans without an intermediate.

The 2003 SARS outbreak began with virus transmission between bats and civet cats, which then passed it on to humans. Similarly, the intermediate host during the 2012 MERS outbreak is believed to have been dromedary camels.

See “Where Coronaviruses Come From”
While the COVID-19 pandemic continues, scientists are using models to look for potential intermediate hosts. As of today (March 16), there have been more than 164,000 cases reported and 6,507 deaths. The first full COVID-19 genome sequences were released in January 2020, enabling researchers to compare the human version of the coronavirus to coronavirus strains already isolated in animals.

A recent paper from the labs of Ralph Baric and Fang Li, published in the Journal of Virology, used the 2003 SARS-CoV as a template to simulate the structure of key COVID-19 proteins and predict in which other species the virus strain could bind in a manner similar to how it does in humans.

The models support the well-accepted idea that the interaction between the receptor-binding domain (RBD) of the coronavirus spike protein and the host receptor angiotensin-converting enzyme 2 (ACE2) controls disease transmission in SARS and COVID-19. In other words, the spike protein grabs hold of ACE2 on host cells to gain entry into cells, where it replicates, bursts open the cell, and spreads to other cells. The researchers then modeled ACE2 receptor proteins belonging to different species to see which ones are vulnerable to SARS-CoV-2 infection. It turns out that pigs, ferrets, cats, orangutans, monkeys, at least some species of bats, and humans have similar levels of affinity for SARS-CoV-2 based on the structural similarity of their ACE2 receptors.

While the team did not rule out civets as intermediate hosts for the current outbreak, they noted several differences in the civet ACE2 receptor that made it less able to bind SARS-CoV-2. The going hypothesis is that the current outbreak started in bats, then moved to another species. While many of the earliest cases in Wuhan were linked to the Huanan Seafood market—which sold seafood and wildlife, including snakes and birds—not every case has a link to it. The wide variety of animal produce available at the market, and structural similarities of ACE2 receptors in many “suspect species” means scientists are still not confident about the transmission chain of SARS-CoV-2.

Although these models create a shortlist of potential reservoir species, “this study doesn’t identify intermediate hosts,” cautions Baric. He says he wants the findings to help researchers develop new coronavirus animal models to test vaccines and drugs and to study disease progression.

“There’s a lot of ongoing experimental work, which I think will be important for actually confirming some of the hypotheses advanced in this paper,” says Andrew Ward, a computational biologist at the Scripps Research Institute who was not involved in the study.

A similar modeling study by a different set of researchers was recently published in the Journal of Medical Virology. The authors propose—based on structural similarities between the viral RBD and host ACE2—that pangolins, snakes, and turtles could be possible intermediate hosts of SARS-CoV-2. The authors note that further research is needed to confirm these findings, while other experts have discredited the idea put forth by a different group of researchers in January that snakes are SARS-CoV-2 hosts.

Confirming the identity of any intermediate host through wet lab experimentation is a difficult process, and researchers may never nab the definitive culprit. “You can test thousands of bats, but to get the coronavirus you have to catch them on the day they’re shedding it,” says Karesh. He explains that it’s now several months since the initial animal-to-human SARS-CoV-2 transmission occurred, and the coronavirus circulation in animals may have dropped off, which would make the original strain even harder to find.

Y. Wan et al., “Receptor recognition by novel coronavirus from Wuhan: An analysis based on decade-long structural studies of SARS,” J Virology, doi:10.1128/JVI.00127-20, 2020.

Claire Jarvis is an Atlanta-based science reporter. Email her at or find her on Twitter @StAndrewsLynx.

Thanks to Nancy Ryan!

Indomethacin has a potent antiviral activity against SARS coronavirus. Antiviral therapy. 11. 1021-30.

Severe acute respiratory syndrome (SARS) is a newly emerging, highly transmissible and fatal disease caused by a previously unknown coronavirus (SARS-CoV).

Existing in non-identified animal reservoirs, SARS-CoV continues to represent a threat to humans because there is no effective specific antiviral therapy for coronavirus infections.

Starting from the observation that cyclopentenone cyclooxygenase (COX) metabolites are active against several RNA viruses, we investigated the effect of the COX inhibitor indomethacin on coronavirus replication.

Work involving infectious SARS-CoV was performed in biosafety level 3 facilities. SARS-CoV was grown in monkey VERO cells and human lung epithelial A549 cells, while canine coronavirus (CCoV) was grown in A72 canine cells.

Antiviral activity was analysed by determining infective virus titres by TCID50, viral RNA synthesis by Northern blot analysis and real-time RT-PCR, and viral protein synthesis by SDS-PAGE analysis after 35S-methionine-labelling. Antiviral efficacy in vivo was determined by evaluating virus titres in CCoV-infected dogs treated orally with 1 mg/kg body weight indomethacin (INDO).

Unexpectedly, we found that INDO has a potent direct antiviral activity against the coronaviruses SARS-CoV and CCoV. INDO does not affect coronavirus binding or entry into host cells, but acts by blocking viral RNA synthesis at cytoprotective doses. This effect is independent of cyclooxygenase inhibition. INDO’s potent antiviral activity (>1,000-fold reduction in virus yield) was confirmed in vivo in CCoV-infected dogs.

The results identify INDO as a potent inhibitor of coronavirus replication and suggest that, having both anti-inflammatory and antiviral activity, INDO could be beneficial in SARS therapy.

Thanks to Ms Nancy

Rapid response to:

Response to the emerging novel coronavirus outbreak
BMJ 2020; 368 doi: (Published 31 January 2020)
Cite this as: BMJ 2020;368:m406

Re: Response to the emerging novel coronavirus outbreak
Dear Editor

With the ongoing spread of COVID-19 virus all around the world and with knowing this concept that not all potential suggested-for-trials drugs against this virus are available in countries like Iran, a rather available and the over-the-counter drug, Naproxen as a promising treatment or prevention agent may be suggested besides the supportive management.

COVID-19 virus is an enveloped, positive-sense, single-stranded RNA beta-coronavirus [1]. Naproxen, a non-steroidal anti-inflammatory drug, has previously been revealed to exert antiviral activity against influenza A virus by impeding nucleoprotein (NP) binding to RNA in a study by Nathalie Lejal et al [2]. Furthermore, Weinan Zheng et al [3] indicated that naproxen is a potential broad, multi-mechanistic anti-influenza virus therapeutic, as it inhibits influenza B virus replication both in vivo and in vitro. Additionally, the NP of influenza B virus (BNP) has a higher binding affinity to naproxen than influenza A virus NP (ANP). Specifically, naproxen targets the NP at residues F209 (BNP) and Y148 (ANP). This interaction antagonizes the nuclear export of NP normally mediated by the host export protein CRM1.

Based on the fact that the COVID-19 virus is single-stranded RNA virus and Naproxen has an antiviral activity via inhibiting nucleoprotein (NP) binding to RNA in the replication process of RNA-viruses like influenza A/B, the use of Naproxen as a probable agent for control of widespread novel coronavirus infection may be assumed.

Published literature relating to the effect of Naproxen on the COVID-19 virus is limited. Clinicians may consider the use of Naproxen for treatment of the infected host cell and spread of infection besides using its anti-inflammatory feature in patients with more severe symptoms. Clinical trials and research may reveal this efficiency.


  1. Zumla, A., Chan, J., Azhar, E. et al. Coronaviruses — drug discovery and therapeutic options. Nat Rev Drug Discov 15, 327–347 (2016).
  2. Lejal, N., Tarus, B., Bouguyon, E., et al. Structure-based discovery of the novel antiviral properties of naproxen against the nucleoprotein of influenza A virus. Antimicrob Agents Chemother 57, 2231–2242 (2013).
  3. Zheng, W., Wenhui, F., Shuang, Z. al. Naproxen exhibits broad anti-influenza virus activity in mice by impeding viral nucleoprotein nuclear export. Cell reports 27, 1875-1885 (2019).

Competing interests: No competing interests

Thank you Judy Lavalle!!

A Big Shout Out​:+1::+1::+1:to

:star::star::star: Mastermind Jocelyn Swayze :star::star::star:

for running this report on recommendation regarding Ibuprofen and other NSAIDs when running a fever for viral infections.

Still no in vitro or in vivo data publication but I’ll go with this for now.

"Ian Jones, a professor of virology at the University of Reading, said that ibuprofen’s anti-inflammatory properties could “dampen down” the immune system, which could slow the recovery process. He added that it was likely, based on similarities between the new virus (SARS-CoV-2) and SARS I, that covid-19 reduces a key enzyme that part regulates the water and salt concentration in the blood and could contribute to the pneumonia seen in extreme cases. “Ibuprofen aggravates this, while paracetamol (acetaminophen (Tylenol)-admin edit) does not,” he said.

Rupert Beale, an infectious diseases researcher at the Francis Crick Institute, had a warning on cortisone, however. “Patients taking cortisone or other steroids should not stop them except on advice from their doctor,” he said.

"Roche has secured approval from China for its anti-inflammation drug Actemra (tocilizumab) to treat patients developing severe complications from covid-19.

Some doctors in Italy, including Paolo Ascierto of the Pascale Hospital in Naples, claim that they have had success treating severely ill patients with the drug, which blocks the key inflammatory molecule interleukin-6.

There is speculation that the drug might prevent fatal “cytokine storms,” in which the immune system of seriously ill patients can cause organ failure."

I dont think lozenges count but,

“The inhibitory effect of Zn2+ on the replication of picornaviruses appeared to be due to interference with viral polyprotein processing. In infections with the coronavirus mouse hepatitis virus (MHV), Zn2+ also interfered with some of the replicase polyproteins cleavages [24], albeit at a much higher concentration (100 µM Zn2+) than used in our studies. Since impaired replicase processing will indirectly affect viral RNA synthesis in the infected cell, we used two recently developed in vitro assays to investigate whether Zn2+ also affects nidovirus RNA synthesis directly. Our in vitro studies revealed a strong inhibitory effect of zinc ions on the RNA-synthesizing activity of isolated EAV and SARS-CoV RTCs. Assays with recombinant enzymes subsequently demonstrated that this was likely due to direct inhibition of RdRp function.”

New insights on the antiviral effects of chloroquine against coronavirus: what to expect for COVID-19?

"Chloroquine has been shown to be capable of inhibiting the in vitro replication of several coronaviruses. Recent publications support the hypothesis that chloroquine can improve the clinical outcome of patients infected by SARS-CoV-2.

The multiple molecular mechanisms by which chloroquine can achieve such results remain to be further explored.

Chloroquine can also act on the immune system through cell signalling and regulation of pro-inflammatory cytokines.

Since SARS-CoV-2 was found a few days ago to utilise the same cell surface receptor ACE2 (expressed in lung, heart, kidney and intestine) as SARS-CoV-1 [85,86] (Table 1), it may be hypothesised that chloroquine also interferes with ACE2 receptor glycosylation thus preventing SARS-CoV-2 binding to target cells.

A recent paper reported that both chloroquine and the antiviral drug remdesivir inhibited SARS-CoV-2 in vitro and suggested these drugs be assessed in human patients suffering from COVID-19"