It causes humans to suffer some diseases the effects of the black plague have not disappeared

October 26, 2022

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It causes humans to suffer some diseases the effects of the black plague have not disappeared Some question the long-term effects that epidemics may have on humans. The study of the Black Plague may provide some evidence of a continuing impact of these epidemics on humans' immune systems A recent research study, published in the journal Nature on October 19, revealed that the Black Plague that swept Europe in the 14th century still has effects on the biology of our bodies today. The study, which was led by researchers from McMaster University, the University of Chicago, the Pasteur Institute and some other scientific institutions, analyzed the DNA of victims as well as survivors of this pandemic, in the hope of knowing Key genes that helped some survive the pandemic, and by studying these differences, researchers have learned how our immune systems have evolved since then. A connection between yesterday and today The Black Plague swept across Europe from 1347-1352, and is still the largest recorded event of human deaths, killing a third to half of the European continent's population. Similar epidemics spread in the same period in Asia and the Middle East, which indicates that this epidemic was part of a widespread global epidemic. In their study, the researchers note that the same genes that provided protection from the black plague are now linked to an increased risk of autoimmune diseases such as rheumatoid arthritis and Crohn's disease (a type of inflammatory bowel disease). To arrive at these findings, the researchers focused their analyzes on a 100-year period before, during, and after the Black Plague pandemic. Scientists have extracted 500 ancient DNA samples from the remains of individuals who died before, or died from, the plague (their samples were collected from the remains of mass burial remains intended for plague victims in East Smithfield 1348-49), who survived it and later died. Then in London. Other samples were also collected from 5 sites in Denmark. Notably, the bacterium Yersinia pestis, which infects humans via the oriental rat flea, was the pathogen that caused the black plague. Therefore, the researchers studied the genetic adaptations that resulted from infection with these bacteria. This led them to identify 4 genes that are all involved in the synthesis of proteins that defend our bodies from pathogens. The team found that copies of these genes either provided protection or made one more susceptible to the plague. Protection mechanism People with identical copies of a specific gene known as (ERAP2) survived the epidemic at much higher rates compared to people with opposite copies of this gene, as identical copies of the gene allowed more effective inactivation of the bacteria Yersinia pestis, through cells. immunoglobulins. According to the press release issued by McMaster University in response to the study, evolutionary geneticist at the university and study leader Hendrik Poinar states that “when a pandemic occurs that kills 30 to 50% of the population, the copies of resistance genes in humans will be selectively preferred. But this does not It means that the bodies of people most vulnerable to infection will succumb." In the beginning, Europeans who lived at the time of the Black Plague were more susceptible to the disease, as their bodies had not previously been exposed to these bacteria until their immune systems were immunized against it. With the recurrence of epidemic waves over the following centuries, death rates decreased because the body had strengthened its defense mechanisms against infection with these bacteria. Yesterday's condoms are today's nurses The researchers estimated that people who had identical copies of the ERAP2 gene had a 40 to 50 percent greater chance of survival than those who did not. This selective feature of certain gene loci is among the strongest of the adaptive features found in humans, as it “shows how a single pathogen can have such a powerful effect on our immune system,” says University of Chicago geneticist and study co-author Luis Barreiro. Over time, our immune systems have evolved to elicit different responses to pathogens, but what was once a protective gene against plague in the Middle Ages is now linked to increased susceptibility to autoimmune diseases. Poinar concludes, "Understanding the mechanisms that shaped the human immune system is key to understanding how previous epidemics - such as the plague - may contribute to our increased vulnerability to disease in the modern era."

Some question the long-term effects that epidemics may have on humans. The study of the Black Plague may provide some evidence of a continuing impact of these epidemics on humans' immune systems

A recent research study, published in the journal Nature on October 19, revealed that the Black Plague that swept Europe in the 14th century still has effects on the biology of our bodies today.

The study, which was led by researchers from McMaster University, the University of Chicago, the Pasteur Institute and some other scientific institutions, analyzed the DNA of victims as well as survivors of this pandemic, in the hope of knowing Key genes that helped some survive the pandemic, and by studying these differences, researchers have learned how our immune systems have evolved since then.

A connection between yesterday and today

The Black Plague swept across Europe from 1347-1352, and is still the largest recorded event of human deaths, killing a third to half of the European continent's population. Similar epidemics spread in the same period in Asia and the Middle East, which indicates that this epidemic was part of a widespread global epidemic.

In their study, the researchers note that the same genes that provided protection from the black plague are now linked to an increased risk of autoimmune diseases such as rheumatoid arthritis and Crohn's disease (a type of inflammatory bowel disease).

To arrive at these findings, the researchers focused their analyzes on a 100-year period before, during, and after the Black Plague pandemic. Scientists have extracted 500 ancient DNA samples from the remains of individuals who died before, or died from, the plague (their samples were collected from the remains of mass burial remains intended for plague victims in East Smithfield 1348-49), who survived it and later died. Then in London. Other samples were also collected from 5 sites in Denmark.

Notably, the bacterium Yersinia pestis, which infects humans via the oriental rat flea, was the pathogen that caused the black plague. Therefore, the researchers studied the genetic adaptations that resulted from infection with these bacteria.

This led them to identify 4 genes that are all involved in the synthesis of proteins that defend our bodies from pathogens. The team found that copies of these genes either provided protection or made one more susceptible to the plague.

Protection mechanism

People with identical copies of a specific gene known as (ERAP2) survived the epidemic at much higher rates compared to people with opposite copies of this gene, as identical copies of the gene allowed more effective inactivation of the bacteria Yersinia pestis, through cells. immunoglobulins.

According to the press release issued by McMaster University in response to the study, evolutionary geneticist at the university and study leader Hendrik Poinar states that “when a pandemic occurs that kills 30 to 50% of the population, the copies of resistance genes in humans will be selectively preferred. But this does not It means that the bodies of people most vulnerable to infection will succumb."

In the beginning, Europeans who lived at the time of the Black Plague were more susceptible to the disease, as their bodies had not previously been exposed to these bacteria until their immune systems were immunized against it. With the recurrence of epidemic waves over the following centuries, death rates decreased because the body had strengthened its defense mechanisms against infection with these bacteria.

Yesterday's condoms are today's nurses

The researchers estimated that people who had identical copies of the ERAP2 gene had a 40 to 50 percent greater chance of survival than those who did not.

This selective feature of certain gene loci is among the strongest of the adaptive features found in humans, as it “shows how a single pathogen can have such a powerful effect on our immune system,” says University of Chicago geneticist and study co-author Luis Barreiro.

Over time, our immune systems have evolved to elicit different responses to pathogens, but what was once a protective gene against plague in the Middle Ages is now linked to increased susceptibility to autoimmune diseases.

Poinar concludes, "Understanding the mechanisms that shaped the human immune system is key to understanding how previous epidemics - such as the plague - may contribute to our increased vulnerability to disease in the modern era."