Two items relevant to long COVID

One of the tricky issues in studying in long COVID is: how widely do researchers cast their net? Initial reports acknowledged that people who were hospitalized and in intensive care may take a while to get back on their feet. But the number of people who had SARS-CoV-2 infections and were NOT hospitalized, yet experienced lingering symptoms, may be greater. A recent report from the United Kingdom, published in PLOS Medicine, studied more than Read more

All your environmental chemicals belong in the exposome

Emory team wanted to develop a standard low-volume approach that would avoid multiple processing steps, which can lead to loss of material, variable recovery, and the potential for Read more

Signature of success for an HIV vaccine?

Efforts to produce a vaccine against HIV/AIDS have been sustained for more than a decade by a single, modest success: the RV144 clinical trial in Thailand, whose results were reported in 2009. Now Emory, Harvard and Case Western Reserve scientists have identified a gene activity signature that may explain why the vaccine regimen in the RV144 study was protective in some individuals, while other HIV vaccine studies were not successful. The researchers think that this signature, Read more

major histocompatibility complex

Risk triangle: immune gene, insecticide, Parkinson’s

Genetic variation and exposure to pesticides both appear to affect risk for Parkinson’s disease. A new study has found a connection between these two risk factors, in a way that highlights a role for immune responses in progression of the disease.

The results are published in the inaugural issue of NPJ Parkinson’s Disease.

The findings implicate a type of pesticide called pyrethroids, which are found in the majority of commercial household insecticides, and are being used more in agriculture as other insecticides are being phased out. Although pyrethroids are neurotoxic for insects, exposure to them is generally considered safe for humans by federal authorities.

The study is the first making the connection between pyrethroid exposure and genetic risk for Parkinson’s, and thus needs follow-up investigation, says co-senior author Malu Tansey, PhD, associate professor of physiology at Emory University School of Medicine.

The genetic variation the team probed, which has been previously tied to Parkinson’s in larger genome-wide association studies, was in a non-coding region of a MHC II (major histocompatibility complex class II) gene, part of a group of genes that regulate the immune system.

“We did not expect to find a specific association with pyrethroids,” Tansey says. “It was known that acute exposure to pyrethroids could lead to immune dysfunction, and that the molecules they act on can be found in immune cells; now we need to know more about how longer-term exposure affects the immune system in a way that increases risk for Parkinson’s.”

“There is already ample evidence that brain inflammation or an overactive immune system can drive the progression of Parkinson’s. What we think may be happening here is that environmental exposures may be altering some people’s immune responses, in a way that promotes chronic inflammation in the brain.”

For this study, Emory investigators led by Tansey and Jeremy Boss, PhD, chair of microbiology and immunology, teamed up with Stewart Factor, DO, head of Emory’s Comprehensive Parkinson’s Disease Center, and public health researchers from UCLA led by Beate Ritz, MD, PhD. The first author of the paper is MD/PhD student George T. Kannarkat.

The UCLA researchers used a California state geographical database covering 30 years of pesticide use in agriculture. They defined exposure based on proximity (someone’s work and home addresses), but did not measure levels of pesticides in the body. Pyrethroids are thought to decay relatively quickly, especially in sunlight, with half-lives in soil of days to weeks. Read more

Posted on by Quinn Eastman in Immunology, Neuro Leave a comment