Do Some People Have Natural Resistance to Ebola?

My Brother says...
The reason it (Ebola) is so
infectious is 10 billion virions per cc of blood, vs 1 million for HIV.
Skin contact with blood usually doesn't transmit HIV, always Ebola...or vomit, stool, urine, phlegm.

Sounds like it is pretty easy to catch...Even on the skin.

B+

Here's some more information I found:

"Another marker linked with people's ability to survive Ebola is a gene called human leukocyte antigen-B, which makes a protein that is important in the immune system. A 2007 study found that people with certain versions of this gene, called B*07 and B*14, were more likely to survive Ebola, while people with other versions, called B*67 and B*15, were more likely to die.

Finally, some people may be resistant to Ebola infection entirely, if they have a mutation in a gene called NPC1. Studies show that, when researchers take cells from people with the NPC1 mutation and try to infect them with Ebola in a laboratory dish, these cells are resistant to the virus.

In European populations, about 1 in 300 to 1 in 400 people have this mutation, Gatherer said. But in some populations, this mutation is more common: in Nova Scotia, between 10 and 26 percent of people have this mutation, Gatherer said. But the frequency of this mutation in African populations is not known, he said."

[link to news.yahoo.com]

You are going to believe a study done in India?

All you have to offer is an ad hominem attack?

To follow up on what I posted above:

"Finally, some people may be resistant to Ebola infection entirely, if they have a mutation in a gene called NPC1. Studies show that, when researchers take cells from people with the NPC1 mutation and try to infect them with Ebola in a laboratory dish, these cells are resistant to the virus."

In the excerpts below, "heterozygous" and "-/+" both refer to mis-matched sets of alleles (A, G, C or T) for the NPC1 gene.

[link to en.wikipedia.org]

In one of the original studies, a small molecule was shown to inhibit Ebola virus infection by preventing the virus glycoprotein from binding to NPC1.[8][10] In the other study, mice that were heterozygous for NPC1 were shown to be protected from lethal challenge with mouse adapted Ebola virus.[7] Together, these studies suggest NPC1 may be potential therapeutic target for an Ebola anti-viral drug.

[link to www.ncbi.nlm.nih.gov]

We assessed the effect of NPC1 mutation in lethal mouse models of EboV and MarV infection. Heterozygous NPC1 (NPC1-/+) knockout mice and their wild type littermates were challenged with mouse-adapted EboV or MarV and monitored for 28 days. Whereas NPC1+/+ mice rapidly succumbed to infection with either filovirus, NPC1-/+ mice were largely protected (Figure 4E).

Last Edited by AnonOne on 10/17/2014 11:54 PM

This is informative,
Thank you

Be true to your quote.

"Think beyond impossible."

or think

Here are excerpts from a couple of articles on NPC1 which are more accessible to the lay person. [Make sure you scroll down to the bottom where the antidepressant imipramine is discussed. I haven't seen this info posted anywhere before.]

[link to www.sciencedaily.com]

In one Nature study, scientists from USAMRIID, Albert Einstein College of Medicine, the Whitehead Institute for Biomedical Research, and Harvard Medical School searched for proteins that Ebola virus might use to enter cells. One such cellular protein, known as Niemann-Pick C1 (NPC1), stood out: The team found that if cells don't make NPC1, they cannot be infected by Ebola virus.

According to the authors, the NPC1 protein is embedded within cell membranes, where it helps transport cholesterol within the cell. However, the absence of NPC1 due to gene mutations causes a rare degenerative disorder called Niemann-Pick disease, in which cells become clogged with cholesterol and eventually die.

To confirm the group's finding that NPC1 is crucial for Ebola virus infection, John M. Dye, Ph.D. and colleagues at USAMRIID used mice that were partially deficient in NPC1 expression, challenging the animals with lethal doses of Ebola virus. Remarkably, most of the mice survived the challenge. Other studies using cells from people with Niemann-Pick disease found that those cells also were resistant to Ebola virus infection. In addition, the researchers showed that treating cells with a compound that blocks NPC1 function inhibited infection.

[link to www.nytimes.com]

But in work published in the journal Nature, researchers from several institutions have identified a protein in host cells that appears to be essential for infection. Cells that lacked the protein remained unharmed after exposure to the virus in the laboratory.

More strikingly, mice that were even partly deficient in the protein (as a result of genetic manipulation) became sick with Ebola but mostly did not die.

…
Probing these resistant cells, Dr. Chandran and his colleagues homed in on a protein, called NPC1, that appeared to be missing.

Under normal circumstances, NPC1, found within a cellular compartment called the endosome, helps bring cholesterol into the cell’s cytoplasm, where it is necessary for healthy function. People whose cells lack the protein typically develop a disease called Niemann-Pick, in which cholesterol and other lipids build up in the liver, spleen and brain.

The researchers took cells from patients with Niemann-Pick disease and exposed them to the Ebola-like virus in the laboratory. The cells survived, further indicating that Ebola relies on NPC1 to enter cells.

…
Dr. Dye and his team verified that when cells without the NPC1 protein were exposed to Ebola, they did not become infected. In addition, mice engineered to produce half the usual amount of NPC1 appeared to be protected as well: They got sick with the virus, but remarkably, most survived. Cells or mice infected with Marburg virus, Ebola’s close cousin, also survived if they lacked or were low in NPC1, the researchers found.

Meanwhile, more evidence was discovered that Ebola needs this protein to wreak havoc. Scientists led by Dr. James Cunningham of Harvard Medical School and Dr. Chandran conducted a broad search for small molecules that might prevent Ebola from entering and killing cells. After screening roughly 40,000 compounds, they zeroed in on one that seemed likely to work by blocking the interaction between the virus and NPC1.

…
One of the Nature papers described a molecule and a derivative that seemed to thwart Ebola’s entry into cells by interacting with NPC1. The other showed that an antidepressant called imipramine, which was known to block NPC1, seemed to prevent infection as well. None of these compounds has been tested against the virus in mice, let alone in primates. But that day may be coming.

Last Edited by AnonOne on 10/18/2014 12:38 AM

seems like caucasians do......

I thnk you are referring to the wrong study.


[link to www.ncbi.nlm.nih.gov]
1Special Pathogens Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. [email protected]

Here is the complete study.
Not Indian at all.

[link to www.ncbi.nlm.nih.gov]

A better article for the more dumbed down populations.
[link to www.sciencedaily.com]

And yes Europeans have more immunity to the Ebola virus.

[link to h.dropcanvas.com]
Various NPC1 mutations lead to various forms of Niemann-Pick's disease, but some mutations are non-pathogenic. Guess what? The most common non-pathogenic mutation (rs1805084) (G to A single nucleotide polymorphism resulting in a glutamine instead of an arginine amino acid) is most common in people of African descent.

[link to www.ncbi.nlm.nih.gov]
In people of European descent the frequency is only about 1~2%. In people of African descent the frequency is about 25%, the most of any demographic examined for it (CEU is European descent in Utah, YRI is a Nigerian population, AFR an African-American population).

Anyone who has already survived an Ebola infection is also likely to have natural resistance toward any future exposures to the virus.

Interestingly, data from long term studies conducted in the hardest hit Ebola-ravaged areas (where Ebola is endemic) indicate that over decades the African populations studied are becoming more and more resistant to Ebola infection.

This stands to reason, however.

That's because someone with more natural resistance to Ebola infection will simply stand a better chance of surviving if they do become infected and, thus, they will live long enough to be able to reproduce.

Ebola infection survivors' offspring will likely also exhibit natural immunity toward Ebola.

Over generations this natural immunity will be selected for - over and over again - and its prevalence in the targetpopulation will increase.

Not really, as Ebola used to kill everyone.

Whole villiages wiped out completely with 0 survivors.

The main reason is that the first outbreak was in 1976.

This means that today is only one generation later.

Let's say 50 people survived this outbreak and they each had 4 kids. That means that there are 200 people alive today with a 50% change of surviving that particular strain of Ebola that used to kill 90%.

Not enough time/generations has passed for natural immunity to form.