Posts Tagged With: antiviral drug

Could Bats be the Pharmacopoeia of the Future?

Tadarida_brasiliensis_outflight_Hristov_Carlsbad_Caverns

This is some of the research that contributed to the recently released Darwin’s Paradox: An international science mysteryhttp://amzn.to/2k8qJgi. Bats have a major role in this books, also the people who try to protect them when they become a target of fearful people during the pandemic.

Could Bats be the Pharmacopoeia of the Future?

Bats have long been considered a threat to humans, but it might be time for that to change.

Of the almost 5,000 mammal species, about 20% are bats, chiroptera (KIE-ROP-TER-A) to be scientific. There are more bats species than any other order except rodents, and they inhabit every continent except Antarctica. Bats are everywhere, and they’re nocturnal, and they fly. What could be scarier than 1,000 species of bats flying into your nightmares?

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How about over 3,000 species of viruses? The International Committee of Taxonomy of Viruses has identified over 3,000 virus species. Unfortunately, a large number of the viruses that are dangerous to people spend their vacations with bats. The list of viruses that are hosted by bats is both long and scary: hepaciviruses, pegiviruses, influenza A virus, hantavirus, paramyxoviruses, and of course lyssaviruses which include rabies.

Besides the viral threat, bats are vampires, as every school child can tell you. NOT! Only 3% of the bat species are vampires, and those are isolated to south and central America.

Recall the major pandemics (Black Plague, Spanish Flu, HIV/AIDS)? All caused by viruses. People die from viruses. Bats host viruses. Bats and Rats … maybe we’d be better off if we killed them all?

This has been the myth, legend, and superstition for millennia. With modern science, it’s time to reconsider.

Science is now asking the question, “Why do viruses that infect and kill humans and other mammals exist benignly in bats?”

If scientists can answer this question, find what protects the bats, we might be able to prevent future pandemics and even cure the common cold.

Chiroptera differ from other mammals in several ways. First, bats reached their current evolutionary point over 33.5 million years ago, while other mammals continued to evolve. Felines didn’t even appear until about 25 million years ago, and people, homo sapiens sapiens, didn’t show up until a few hundred thousand years ago.

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This might explain why bats are better at dealing with viruses. Some scientists suggest that given 30 million years bats had time to evolve better defenses than we could in a few hundred thousand. Bats also had strong evolutionary pressures since they live in large, dense colonies – ideal for spreading viral infections. This is very different from primates which evolved in small isolated groups.

Others suggest that it’s just a numbers game. Given a thousand species of bats, to our one, they had a better chance to get lucky. This is supported by the rodents which have even more species and also host lots of viruses.

The third line of investigation is the high metabolism required for flight. This, combined with the observation that bats don’t seem to get cancer, leads to the hypothesis that their DNA repair mechanisms work faster and better.

This third hypothesis brings up another bat anomaly: not only are they more resistant to viral diseases, but they also live longer than expected. Are these two related? Maybe?

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Regardless, the denizens of Chiroptera have antiviral secrets that we need and science is working to find them. Today more scientists study the biology of bats, and more bats are getting their DNA sequenced. Perhaps soon we will live longer and healthier because of those scary, night flying, echolocating bats.

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Categories: Bats, Viruses | Tags: , , , , , , , , | 1 Comment

How to stop viral vampires: virus life cycle and antiviral 101

Cyto Citadel 2

This is some of the research that contributed to the recently released Darwin’s Paradox: An international science mysteryhttp://amzn.to/2k8qJgi. Anti-virals are way more complicated that I first imagined.

The Battle for Cyto Citadel – A Primer in Antiviral Warfare

This is the story of viral vampires and their clone armies attacking the friendly territory defended by cyto citadels. Viruses, not quite alive, walking dead, attack cells, armored castles (Cyto Cidadel), defended by vaccines and drugs. Some are defeated.

Skirmish 1 – VACCINATION

All around the Cyto Citadel are roaming squads of deadly B-cell skirmishers and T-cell marauders searching for viral vampires. These forces are very effective and win most of their battles leaving vanquished vampires in their wake.

Unfortunately, they only attack vampires they have seen before. Any new viral vampires get by them unnoticed as if they were wearing invisibility cloaks.

Vaccines introduce B-cells and T-cells to recognized vampires of the viral armies, such as measles, mumps, rubella, polio, and hepatitis. Captain Cytoplasm uses as many vaccines as possible, but still many viral vampires get pass this defense, especially influenza viruses which constantly mutate into unrecognizable forms.

Skirmish 2 – ATTACHMENT

When the invisibility-cloaked vampires approach the Cyto Citadel, their first objective is to attach to the citadel walls to stage their break in. Medical sentries can stop some viral attacks before they attach to the wall.

Docosanol dragoons prevent herpes simplex viral vampires from attaching to the citadel walls. Unfortunately, if these loyal dragoons do not recognize the viral vampires, the invaders slip by undeterred.

Skirmish 3 – ENDOCYTOSIS

With the vampires at the wall, they need to worm their way through. The Cyto Citadel has strong walls to thwart this intrusion.

For example, even the dreaded HIV horde, causers of the AIDS scourge, can not penetrate the citadel without the help of CCR5 crackers or CXCR4 crashers. Blockers can be brought against CCR5 and CXCR4 to isolate the HIV horde outside the Citadel where they can do no damage.

Skirmish 4 – UNCOATING

Once inside, all is not lost. First of all the viral vampires come heavily armored for the battle to breach the citadel walls. Before they can do their real damage, they need to remove this armor. This is called uncoating.

Two antiviral armies, the amantadine arsenal, and the rimantadine rangers, prevent influenza vampires from releasing acid to dissolve their armor. Without this acid, they are stuck inside their own armor and helpless to do any damage.

Skirmish 5 – MUTAGENESIS

Once uncoated, the viral vampires break into the citadel storeroom to steal parts to build a vampire clone army. This is the last thing the citadel defenders want: a viral vampire clone army!

The citadel storerooms are infiltrated by ribavirin robots that fool the vampires to accepting mutating parts. When the vampires build clones from mutating parts, errors pile up and the clones die from error catastrophe. Too many errors equal dead clones.

Skirmish 6 – SYNTHESIS

Another attack on the synthesis of the viral clone army is to supply the vampires with the wrong parts. Reverse Transcriptase quartermasters delivering the wrong parts from inventory can foil the cloning efforts of some of the HIV horde, and the Hepatitis B horde also. The parts look right, but when used, the result is defective.

Skirmish 7 – REPLICATION

If a few clones get this far, all is not lost. Building a clone is a slow process. Unfortunately, once they are operational, they can replicate themselves. From a few clones, they can grow a full clone army.

Patrol of protease (pronounced PRO-TEA-AZE) inhibitors can stop the replication. Unfortunately, like all the fighters in the Cyto Citadel, patrols are very specific about who they will attack. Smart citadel defenders recruit as many different protease inhibitor patrols as possible.

If the HIV horde invades, the saquinavir, ritonavir, indinavirnelfinavir, and amprenavir patrols are recommended. For the hepatitis C horde, different patrols are needed: boceprevir and telaprevir.

The last defense: Skirmish 8 – EXOCYTOSIS

If the clone army is successfully put together, the Cyto Citadel is lost, but a lost battle is not a lost war. As a last ditch effort, oseltamivir (aka Tamaflu) can prevent the clone army from breaching the walls from the inside. With the clone army trapped in this citadel, other Citadels can be safe.

Good News and Bad News

The good news is that there are many ways the Cyto Citadel defenders can stop the viral vampires and their clone armies.

The bad news is that all the defenders are all very specific, and each different vampire attack must be met with the correct response. Unfortunately, some vampires mutate rapidly, so there is an arms race to keep finding new defenders. Even worse, for some viral attacks, there are no known defenders.

Map credit: Dyson Logos rpgcharacters.wordpress.com.

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Categories: Diseases, Pharmaceutical Industry | Tags: , , , , , , | Leave a comment

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