Delivering impact to support AIDS research

LGC is helping to ensure that research into a cure for HIV is based on sound fundamental measurements.

Over 36 million people currently live with HIV, with approximately 2 million becoming infected each year (WHO 2015). Although HIV can be successfully managed with combination antiretroviral therapy (cART), the therapy must be continued indefinitely as no cure presently exists. This can be challenging in regions with high HIV prevalence and long-term use can potentially have toxic side effects.

One barrier to curing HIV is the presence of infected host cells that are not targeted by current therapies but lay dormant (so-called ‘viral reservoir’). These cells have the potential to become re-activated so novel strategies to cure HIV aim to target this reservoir. To determine whether these new approaches are successful, accurate and robust, methods for measuring HIV DNA are required.

The Molecular and Cell Biology team at LGC perform research to support accurate and reliable measurement as part of our National Measurement Laboratory (NML) role. Recent work by NML scientists comparing different molecular methods (qPCR, digital PCR) for quantification of HIV DNA has raised some concerns around the current popular choice of calibrator used to compare results between HIV clinical studies (8E5, ATCC® CRL-8993). It appears to lose HIV DNA copies during cell growth, potentially producing misleading estimates of how much HIV DNA is present and affecting whether novel strategies towards curing HIV are deemed successful or not.

Based in part on our work, the NIH AIDS Reagent Program, which provides critical reagents and resources to support research in the areas of AIDS therapeutics and vaccine development, has recently highlighted the potential instability of the standard on its reagent database to support the research community and enable the best chances of success.

 

 

Citation:

Busby E et al. Instability of 8E5 calibration standard revealed by digital PCR risks inaccurate quantification of HIV DNA in clinical samples by qPCR (2017) Sci Rep 7(1):1209. doi:10.1038/s41598-017-01221-5

The importance of iodine – are you drinking enough milk?

Ensuring the safety of the food we eat is of paramount importance. Iodine is an essential element naturally found in some foods. Insufficient amounts of iodine in the diet results in low levels of thyroid hormones, which are responsible for regulation of metabolism.

In pregnant women and infants iodine is of particular importance as it plays a critical role in brain development. The primary sources of iodine for most people are milk and dairy products but due to increases in dairy intolerance and changes in diet, milk-products are being increasingly substituted for non-milk alternatives.

To identify the impact that such dietary changes might have on iodine levels across the population, an understanding of the levels of iodine naturally present in milk is necessary. This includes the effects of seasonal variations or fat content and any processing effects of pasteurisation which might reduce the iodine content. These variations have been investigated by the Nutrition Innovation Centre for Food and Health (NICHE), Ulster University, with milk samples collected over a 12-month period. However, these differences needed to be measured accurately in order to properly determine the influence different conditions have on iodine content.

As part of the UK’s National Measurement Laboratory (NML) role, scientists at LGC have developed a high accuracy quantitative method (inductively-coupled plasma mass spectrometry) for the analysis of iodine in milk and milk-products to support the regulation on iodine levels in infant formulas. Using this expertise, we were able to support the work being done at Ulster University, providing the analytical capability required to determine the levels of iodine in milk under a variety of conditions.

Of the collaboration, Maria O’Kane, lead author on the paper, said: “LGC facilitated my visit to the laboratory in Teddington and enabled me to undertake analysis of the milk samples collected using high accuracy ICP-MS. The expert staff at LGC supported my learning and enabled me to develop a greater knowledge and understanding of ICP-MS analysis.”

The findings were recently published in the Journal of Nutrition, where Maria concluded that consuming additional cow milk can significantly increase the amount of iodine observed in the urine of women of childbearing age.

This work will help our understanding of current iodine intake and support future research in this area and clearly demonstrates the impact the UK’s National Measurement Laboratory (NML) can have on real-world problems, protecting human health and ensuring the safety of our food.