PFAS have demonstrated the ability to inhibit white blood cell systems to fight off intruders

A recent investigation revealed that the PFAS chemical GenX inhibits the neutrophil respiratory burst, a crucial defense mechanism for white blood cells known as neutrophils. The finding is an initial step toward better understanding how both legacy and emerging PFAS chemicals may influence one's innate immune system.

Per- and polyfluoroalkyl chemicals are an integral component of many consumer and industrial products, enabling them to resist moisture, stains and lubricants. Across the globe there are more than 12,000 known PFAS - like GenX - that can be used to create resilient products.

Drake Phelps, Ph.D student at North Carolina State University and lead author of this study concurs: It is generally acknowledged that PFAS are detrimental to the adaptive immune system, yet comparatively less research has been devoted towards their impact on innate immunity.

The human immune system comprises two distinct but interwoven branches: adaptive and innate. The adaptive arm boasts potent T cell and B cell units that are capable of remembering pathogens encountered during previous encounters, yet their response lags behind even days after detection.

The bodys innate immune system is its first line of defense, and is equipped with a formidable arsenal of white blood cells that can mobilize to respond quickly to any potential invasion. Neutrophils are among these combatants - they produce minute quantities of reactive oxygen species (imagine the like of bleach or hydrogen peroxide) within their livers which have the ability to eradicate pathogens instantaneously via a process termed the respiratory burst.

Drake and his team conducted an in-depth study of the impact of nine environmentally relevant PFAS on zebrafish embryos, neutrophil -like cells (cells that can be chemically manipulated to behave like neutrophils), as well as human neutrophil cell cultures derived from donor blood samples.

Emerging PFAS are chemicals, such as GenX, which have been introduced to replace legacy pollutants that have been proven toxic. The compounds found in this analysis were both present in the Cape Fear River and detected within human blood serum samples; originating from drinking water that was sourced from this river system.

The embryos and cells were subjected to concentrations of each compound equaling 80 micromolar solutions:
perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid potassium salt (PFOS-K), perfluorononanoic acid (PFNA), perfluorohexanoic acid (PFHxA), perfluorohexane sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS), ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX), 7H-perfluoro-4-methyl-3,6-dioxa-octane sulfonic acid (Nafion byproduct 2), and perfluoromethoxyacetic acid sodium salt (PFMOAA-Na).

Only GenX inhibited the respiratory burst in embryonic zebrafish, neutrophil-like cells, and human neutrophils. In addition to this inhibitory effect, PFHxA likewise suppressed activity; however it was only observed for embryonic zebrafish and neutrophil-like cells.

Researchers from this preliminary investigation have cautioned that while their findings are intriguing, they do not provide definitive answers.

The investigation into the longest chemical exposure in this study was only four days in duration, with which its impossible to compare to the decades-long human exposure to PFAS that people living along Cape Fear River experience on a daily basis. However, the researchers did examine PFAS doses at a high concentration over an abbreviated period of time when compared with exposures experienced by residents within the Cape Fear Basin who were exposed to low levels of multiple PFas congeners over prolonged periods.

“So while we can say that we see a toxic effect from a high dose in the cell lines, we can’t yet say what effects long-term exposure may ultimately have on the immune system. This paper isn’t the end of the road – it’s the first step. Hopefully our work may help prioritize further study of these two chemicals.”

Source: NC State University News