Particulate matter reactivates sleeping viruses in the lungs

Particulate pollution arouses inactive viruses
Increased particulate matter pollution is associated with a variety of health impairments. Scientists from the Helmholtz Zentrum München have now discovered that the particulate matter apparently also activates "sleeping viruses" in the lungs. The results of their study published the researchers in the journal "Particle and Fiber Toxicology".

The details of the research teams around Dr. med. Tobias Stöger and Professor According to Heiko Adler from Helmholtz Zentrum München, fine dust causes dormant viruses in the lungs. The nanoparticles from combustion engines would activate viruses that rest in lung tissue cells. This could potentially increase susceptibility to chronic inflammatory processes and remodeling in the lungs.

The fine dust from internal combustion engines can reactivate dormant viruses in the lungs. (Image: WS-Design / fotolia.com)

Fine dust is a massive burden on health
The high particulate matter concentrations - especially in cities and along busy roads - have far-reaching health consequences. Thus, it is known from previous investigations that particulate matter favors asthma, smoker's cough and the like. The risk of cardiovascular diseases, strokes and lung diseases at high particulate matter concentration also increases. In the past year, studies have shown that nanoparticles also have a harmful effect in the brain and that the fine dust increases the cancer risk massively. The high particulate matter pollution in many German inner cities is therefore extremely critical.

Sleeping viruses are a long-term risk
The now observed effect on "sleeping viruses" is another critical aspect of particulate matter pollution. "Sleeping viruses" are viruses that hide in an inactive state in the cells of the host, explain the scientists of the Helmholtz Zentrum München. In technical jargon this condition is called a latent infection. If weakening of the immune system occurs or certain conditions change, the viruses become active again, begin to multiply and destroy the host cell, the experts report.

Inhalation of particulate matter with an inflammatory effect
The research team around Dr. Stöger from the Institute of Lung Biology and Professor Adler from the Department of Lung Repair and Regeneration at Helmholtz Zentrum München has now investigated whether particulate matter could be associated with the reactivation of a latent infection. Because "from previous model studies, we already knew that inhaling nanoparticles has an inflammatory effect and changes the immune system," reports study leader Stöger.

Indications of a reactivation of the viruses
In their current study, the scientists have now "tested the influence of nanoparticles, as they typically arise in the combustion of fossil fuels, in a test model for a specific herpes virus infection". They observed a marked increase in viral proteins produced only with active virus replication. "Metabolic and gene expression analyzes also revealed patterns similar to those of an acute infection," adds Philippe Schmitt-Kopplin, Head of the Department of Analytical BioGeoChemistry at Helmholtz Zentrum München, who was also involved in the study.

Molecular process still unclear
Exposure to nanoparticles in the lungs may, according to the researchers, reactivate latent herpesviruses - at least in the experimental model. Now, further studies should examine whether the results can also be applied to humans. This would be of far-reaching importance. Because: "many people carry herpesviruses in themselves and patients with idiopathic pulmonary fibrosis are particularly affected," explains Prof. Adler. If the results are confirmed in humans, the next step is to investigate the molecular course of the reactivation of latent herpesviruses by particle inhalation.

Hope for new therapeutic options
According to the researchers, experiments on special cell culture models should help to elucidate the exact mechanism of virus reactivation by nanoparticles. This would, if appropriate, offer the possibility of therapeutically influencing the pathway as well. In addition, the scientists plan to examine in long-term studies "to what extent a repeated particle exposure with appropriate virus reactivation can lead to chronic inflammatory and remodeling processes in the lungs," explains Dr. med. Stoeger. (Fp)