London: While, healthy people usually have no problem if microorganisms find their way into their bodies as their immune defence system will put the spores out of action, a specific type of fungus can threaten lives with a compromised immune system, such as AIDS patients or who are immunosuppressed following an organ transplantation, says a new study.
Researchers have now discovered how the fungus — Aspergillus fumigatus — knocks out the immune defences, enabling a potentially fatal fungal infection to develop.
Among alternative factors, it is gliotoxin — a potent mycotoxin — that is responsible for the pathogenicity of Aspergillus fumigatus.
Pathogenicity refers to the power of Associate in Nursing organism to cause illness.
“It was known that this substance has an immunosuppressive effect, which means that it weakens the activity of cells of the immune defence system.
However, it had not been clear antecedently how precisely this happens,” said Oliver Werz, Professor at the University of Jena in Germany.
To achieve this, they brought immune cells into contact with synthetically produced gliotoxin. These cells — neutrophilic granulocytes — represent the first line of the immune defence system.
Their task is to notice pathogens and eliminate them.
As presently in and of itself a cell comes into contact with a microorganism, for example a fungus, it releases specific messenger substances (leukotrienes) into the blood, which attract other immune cells.
Once a sufficiently large number of immune cells has gathered, they can render the intruder harmless, findings showed, published in the journal, Cell Chemical Biology.
This doesn’t happen if the microorganism Aspergillus fumigatus is involved.
Gliotoxin ensures that production of the messenger substance leukotrieneB4 in the neutrophilic granulocytes is inhibited, so that they are unable to send a signal to other immune cells.
This is caused by a particular accelerator (LTA4 hydrolase) being converted by the phytotoxin.