Monday, May 18, 2020

WHAT I HAVE LEARNED SO FAR.




Gentle People:

 Here is something else that I have learned so far and it seems to contain conflicting information. Judge for yourselves.
1.  According to the Japanese, the SARS-CoV-2 protein basically blocks the human cell from recognizing that a virus is present. Human interferons: Type I and type III IFNs, establish the cellular state of viral resistance, as well as activate the adaptive immune responses to viruses (
  Successful viral pathogens, however,  have evolved mechanisms to escape both immune recognition and suppress the functions of IFNs and ISGs. Many viral proteins are dedicated to modulating the host IFN response. These mechanisms have been extensively investigated for SARS-CoV and MERS-CoV ( It has been proven that many viruses block interferon from signalling for help and when Interferon is not expressed, it consequently does not signal B cells and T cells to arrive and fight the virus. The virus is then uninhibited and infects every cell in the host body...
2.  Conflicting with this concept is the idea that a cytokine storm response is created by the SARS-CoV-2.  A cytokine storm occurs when too many T cells gather to fight an infection and do more damage than good. When too many killer T cells enter the lungs, they can destroy both the virus and the  cells in the lungs. The Japanese claim they did not find T cells in the lungs of their patients. This would be possible if interferon was inhibited by the SARS-CoV-2 from signalling the B and T cells. 
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In another new study, scientists in Japan last week identified how SARS-CoV-2 accomplishes its genetic manipulation. Its ORF3b gene produces a protein called a transcription factor that has “strong anti-interferon activity,” Kei Sato of the University of Tokyo and colleagues found the transcription factor to be stronger than the original SARS virus or influenza viruses. The SARS-CoV-2 protein basically blocks the human cell from recognizing that a virus is present, in a way that prevents interferon genes from being expressed. Interferon genes call for help from human B cells and T cells while slowing down the SARS virus. Without interferon genes, no call for help is issued and the virus continues to infect the cells.
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 The more than 100 COVID-19 vaccines in development mainly focus on another immune response: antibodies. Antibody proteins are made by B cells and ideally latch onto SARS-coV-2 and prevent it from entering cells. (They do, that is, if they are triggered by interferon to locate the SARS-CoV-2. )

 T cells thwart infections in two different ways. 1. Helper T cells spur B cells into making antibody proteins and other immune defenders into action, and 2. killer T cells target and destroy infected cells. The severity of disease can depend on the strength of the killer T cell response, which if too strong, may trigger a cytokine storm response and do more harm than good. It can kill rather than cure.

 For reasons that are not completely understood, too many immune cells can be sent to the infection site and when this happens a particular type of molecule in the body, known as a cytokine, is activated. The immune cells at the infection site signal more immune cells to flood the area. This creates a cytokine storm where far too many immune cells are activated to fight the infection. The reaction ends up inflaming the tissue surrounding the infection and both the virus and the human cell...die!

 When the infection is in the lungs a severe inflammation created by the cytokine reaction can cause permanent damage and doctors who place an oxygen tube into an already damaged lung may be doing more harm than good. A prolonged cytokine storm will eventually shut down breathing completely as infected lung cells lose the capacity to transfer oxygen to blood cells. This is usually when a doctor will use a ventilator to place an oxygen tube into a damaged lung of a patient. A cytokine storm is what makes the reaction so deadly in certain epidemic strains such as bronchitis and other varieties of influenza, Pneumoniasepsis, and possibly rheumatoid arthritis are susceptible to triggering a cytokine storm.

 Using bioinformatics tools, a team led by Shane Crotty and Alessandro Sette, immunologists at the La Jolla Institute for Immunology, predicted which viral protein pieces would provoke the most powerful T cell responses. They then exposed immune cells from 10 patients who had recovered from mild cases of COVID-19 to these viral snippets.
All of the patients carried helper T cells that recognized the SARS-CoV-2 spike protein, which enables the virus to infiltrate our cells. They also harbored helper T cells that react to other SARS-CoV-2 proteins. And the team detected virus-specific killer T cells in 70% of the subjects, they report today in Cell. “The immune system sees this virus and mounts an effective immune response,” Sette says.
The results jibe with those of a study posted as a preprint on medRxiv on 22 April by immunologist Andreas Thiel of the Charité University Hospital in Berlin and colleagues. They 
identified helper T cells targeting the spike protein in 15 out of 18 patients hospitalized with COVID-19.


 Comments (8)

Presence of SARS-CoV-2 reactive T cells in COVID-19 patients and healthy donors

Julian BraunLucie LoyalMarco FrentschDaniel WendischPhilipp GeorgFlorian KurthStefan HippenstielManuela DingeldeyBeate KruseFlorent FauchereEmre BaysalMaike MangoldLarissa HenzeRoland LausterMarcus MallKirsten BeyerJobst RoehmelJuergen SchmitzStefan MiltenyiMarcel A MuellerMartin WitzenrathNorbert SuttorpFlorian KernUlf ReimerHolger WenschuhChristian DrostenVictor M CormanClaudia Giesecke-ThielLeif-Erik SanderAndreas Thiel

Abstract

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a rapidly unfolding pandemic, overwhelming health care systems worldwide1. Clinical manifestations of Corona-virus-disease 2019 (COVID-19) vary broadly, ranging from asymptomatic infection to acute respiratory failure and death2, yet the underlying physiological conditions and mechanisms for this high variability are still unknown. Also, the role of host immune responses in viral clearance and its involvement in pathogenesis remains unresolved. For SARS-CoV (2002/03), however, CD4+ T cell responses are generally associated with positive outcomes3,4, while cellular immune responses to SARS-CoV-2 have not yet been investigated. Here we describe an assay that allows direct detection and characterization of SARS-CoV-2 spike glycoprotein (S)-reactive CD4+ T cells in peripheral blood. We demonstrate the presence of S-reactive CD4+ T cells in 83% of COVID-19 patients, as well as in 34% of SARS-CoV-2 seronegative healthy donors, albeit at lower frequencies. Strikingly, in COVID-19 patients S-reactive CD4+ T cells equally targeted both N-terminal and C-terminal parts of S whereas in healthy donors S-reactive CD4+ T cells reacted almost exclusively to the Cterminal part that is a) characterized by higher homology to spike glycoprotein of human endemic "common cold" coronaviruses, and b) contains the S2 subunit of S with the cytoplasmic peptide (CP), the fusion peptide (FP), and the transmembrane domain (TM) but not the receptor-binding domain (RBD). S-reactive CD4+ T cells from COVID-19 patients were further distinct to those from healthy donors as they co-expressed higher levels of CD38 and HLA-DR, indicating their recent in vivo activation. Our study is the first to directly measure SARS-CoV-2-reactive T cell responses providing critical tools for large scale testing, in depth epitope mapping and characterization of potential cross-reactive cellular immunity to SARS-CoV-2. The presence of pre-existing SARS-CoV-2-reactive T cells in healthy donors is of high interest but larger scale prospective cohort studies are needed to assess whether their presence is a correlate of protection or pathology. Results of such studies will be key for a mechanistic understanding of the SARS-CoV-2 pandemic, adaptation of containment methods and to support vaccine development.

Competing Interest Statement

The authors Jürgen Schmitz, Stefan Miltenyi, Florian Kern, Ulf Reimer, Holger Wenschuh are employed at non-academic cooperations.

Funding Statement
















Duration of contamination on objects and surfaces
Although the virus was greatly reduced, viable SARS-CoV-2 was measured for this length of time:
  • Plastic: up to 2-3 days
  • Stainless Steel: up to 2-3 days
  • Cardboard: up to 1 day
  • Copper: up to 4 hours

Floor

"The rate of positivity was relatively high for floor swab samples (ICU 7/10, 70%; GW 2/13, 15.4%), perhaps because of gravity and air flow causing most virus droplets to float to the ground.
In addition, as medical staff walk around the ward, the virus can be tracked all over the floor, as indicated by the 100% rate of positivity from the floor in the pharmacy, where there were no patients.
Furthermore, half of the samples from the soles of the ICU medical staff shoes tested positive. Therefore, the soles of medical staff shoes might function as carriers. The 3 weak positive results from the floor of dressing room 4 might also arise from these carriers. We highly recommend that persons disinfect shoe soles before walking out of wards containing COVID-19 patients." [source]
  

Friday, May 15, 2020

T cells target Covid-19 virus.

 Here we describe an assay that allows direct detection and characterization of SARS-CoV-2 spike glycoprotein (S)-reactive CD4+ T cells in peripheral blood. We demonstrate the presence of S-reactive CD4+ T cells in 83% of COVID-19 patients, as well as in 34% of SARS-CoV-2 seronegative healthy donors, albeit at lower frequencies. Strikingly, in COVID-19 patients S-reactive CD4+ T cells equally targeted both N-terminal and C-terminal parts of S whereas in healthy donors S-reactive CD4+ T cells reacted almost exclusively to the Cterminal part that is a) characterized by higher homology to spike glycoprotein of human endemic "common cold" coronaviruses, and b) contains the S2 subunit of S with the cytoplasmic peptide (CP), the fusion peptide (FP), and the transmembrane domain (TM) but not the receptor-binding domain (RBD). S-reactive CD4+ T cells from COVID-19 patients were further distinct to those from healthy donors as they co-expressed higher levels of CD38 and HLA-DR, indicating their recent in vivo activation. Our study is the first to directly measure SARS-CoV-2-reactive T cell responses providing critical tools for large scale testing, in depth epitope mapping and characterization of potential cross-reactive cellular immunity to SARS-CoV-2. The presence of pre-existing SARS-CoV-2-reactive T cells in healthy donors is of high interest but larger scale prospective cohort studies are needed to assess whether their presence is a correlate of protection or pathology. Results of such studies will be key for a mechanistic understanding of the SARS-CoV-2 pandemic, adaptation of containment methods and to support vaccine development.

Competing Interest Statement

The authors Jürgen Schmitz, Stefan Miltenyi, Florian Kern, Ulf Reimer, Holger Wenschuh are employed at non-academic cooperations.

Funding Statement

We thank Ulf Klein (Leeds, UK) und Hans-Peter Herzel (Berlin) for critical discussion. This work was supported by the German Research Foundation (KFO339 to J.B and F.F., SFB-TR84 projects A4, B6 to S.H., B8 to M.M., C6 to M.W., C8, C10 to L.E.S., C9 to M.W, N.S., and by the German Federal Ministry of Education and Research (BMBF-RAPID to S.H., C.D., and CAPSyS to M.W., N.S.).

Author Declarations

All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.
Yes
All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.
Yes
I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).
Yes
I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.
Yes

T cells bode well for long term immunity.

Immune hunters called T cells can seek and destroy a cell (green) infected with and making copies of SARS-CoV-2 (yellow).
NIAID

T cells found in COVID-19 patients ‘bode well’ for long-term immunity

Sciences COVID-19 reporting is supported by the Pulitzer Center.
Immune warriors known as T cells help us fight some viruses, but their importance for battling SARS-CoV-2, the virus that causes COVID-19, has been unclear. Now, two studies reveal infected people harbor T cells that target the virus—and may help them recover. Both studies also found some people never infected with SARS-CoV-2 have these cellular defenses, most likely because they were previously infected with other coronaviruses.
“This is encouraging data,” says virologist Angela Rasmussen of Columbia University. Although the studies don’t clarify whether people who clear a SARS-CoV-2 infection can ward off the virus in the future, both identified strong T cell responses to it, which “bodes well for the development of long-term protective immunity,” Rasmussen says. The findings could also help researchers create better vaccines.
The more than 100 COVID-19 vaccines in development mainly focus on another immune response: antibodies. These proteins are made by B cells and ideally latch onto SARS-CoV-2 and prevent it from entering cells. T cells, in contrast, thwart infections in two different ways. Helper T cells spur B cells and other immune defenders into action, whereas killer T cells target and destroy infected cells. The severity of disease can depend on the strength of these T cell responses.
Using bioinformatics tools, a team led by Shane Crotty and Alessandro Sette, immunologists at the La Jolla Institute for Immunology, predicted which viral protein pieces would provoke the most powerful T cell responses. They then exposed immune cells from 10 patients who had recovered from mild cases of COVID-19 to these viral snippets.
All of the patients carried helper T cells that recognized the SARS-CoV-2 spike protein, which enables the virus to infiltrate our cells. They also harbored helper T cells that react to other SARS-CoV-2 proteins. And the team detected virus-specific killer T cells in 70% of the subjects, they report today in Cell. “The immune system sees this virus and mounts an effective immune response,” Sette says.
The results jibe with those of a study posted as a preprint on medRxiv on 22 April by immunologist Andreas Thiel of the Charité University Hospital in Berlin and colleagues. They identified helper T cells targeting the spike protein in 15 out of 18 patients hospitalized with COVID-19.
The teams also asked whether people who haven’t been infected with SARS-CoV-2 also produce cells that combat it. Thiel and colleagues analyzed blood from 68 uninfected people and found that 34% hosted helper T cells that recognized SARS-CoV-2. The La Jolla team detected this crossreactivity in about half of stored blood samples collected between 2015 and 2018, well before the current pandemic began. The researchers think these cells were likely triggered by past infection with one of the four human coronaviruses that cause colds; proteins in these viruses resemble those of SARS-CoV-2.
The results suggest “one reason that a large chunk of the population may be able to deal with the virus is that we may have some small residual immunity from our exposure to common cold viruses,” says viral immunologist Steven Varga of the University of Iowa. However, neither of the studies attempted to establish that people with crossreactivity don’t become as ill from COVID-19.
Before these studies, researchers didn’t know whether T cells played a role in eliminating SARS-CoV-2, or even whether they could provoke a dangerous immune system overreaction. “These papers are really helpful because they start to define the T cell component of the immune response,” Rasmussen says. But she and other scientists caution that the results do not mean that people who have recovered from COVID-19 are protected from reinfection.
To spark production of antibodies, vaccines against the virus need to stimulate helper T cells, Crotty notes. “It is encouraging that we are seeing good helper T cell responses against SARS-CoV-2 in COVID-19 cases,” he says. The results have other significant implications for vaccine design, says molecular virologist Rachel Graham of the University of North Carolina, Chapel Hill. Most vaccines under development aim to elicit an immune response against spike, but the La Jolla group’s study determined that T cells reacted to several viral proteins, suggesting vaccines that sic the immune system on these proteins as well could be more effective. “It is important to not just concentrate on one protein,” Graham says.

Thursday, May 14, 2020

Drugs Against Covid-19



Review

2020 Apr 29;157:104859.
 doi: 10.1016/j.phrs.2020.104859. Online ahead of print.

Candidate Drugs Against SARS-CoV-2 and COVID-19

Affiliations 

Abstract

Outbreak and pandemic of coronavirus SARS-CoV-2 in 2019/2020 will challenge global health for the future. Because a vaccine against the virus will not be available in the near future, we herein try to offer a pharmacological strategy to combat the virus. There exists a number of candidate drugs that may inhibit infection with and replication of SARS-CoV-2. Such drugs comprise inhibitors of TMPRSS2 serine protease and inhibitors of angiotensin-converting enzyme 2 (ACE2). Blockade of ACE2, the host cell receptor for the S protein of SARS-CoV-2 and inhibition of TMPRSS2, which is required for S protein priming may prevent cell entry of SARS-CoV-2. Further, chloroquine and hydroxychloroquine, and off-label antiviral drugs, such as the nucleotide analogue remdesivir, HIV protease inhibitors lopinavir and ritonavir, broad-spectrum antiviral drugs arbidol and favipiravir as well as antiviral phytochemicals available to date may limit spread of SARS-CoV-2 and morbidity and mortality of COVID-19 pandemic.
Keywords: Arbidol; COVID-19; Camostat; Chloroquine; Drugs; Favipiravir; Lopinavir; Phytochemicals; Remdesivir; Ritonavir; SARS-CoV-2.

Conflict of interest statement

Declaration of Competing Interest None.

Figures



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Fig. 1

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References

    1. Lu R., Zhao X., Li J., Niu P., Wang B., Wu H. Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding. Lancet. 2020;395(10224):565–574. - PMC - PubMed
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