Metals are essential for the adequate functioning of all life. A key element is iron, which plays a vital role in many metabolic processes, such as oxygen transport by haemoglobin. Additionally, iron is vital for immunity against infection, where it is harnessed as an effective catalyst in activated T-cells during periods of infection¹. Iron deficiency anaemia is a condition that affects around 1.2 billion people worldwide and impairs many aspects of physiology, including immunity². Its prevalence is amplified in low-to middle-income countries, where the combination of malnutrition and endemic diseases result in unfavourable fates of disease progression and mortality³.

Precise measurements of iron within individual T-cells may provide a new and insightful tool for immunological research, where it could provide a metabolism-related biomarker of cellular immunological status. Such studies have traditionally adopted bulk-digestion and measurement approaches, but the single resultant average value can be misleading if the population displays cellular heterogeneity, which may occur under conditions of iron deficiency. Here we utilise single cell ICP-MS to rapidly scan the metallomic profile of large cell populations (>200 cells/minute). We evaluate the method developments that are required to enable the precise determination of metal uptake into cells, from experiments conducted on both human and mouse lymphocytes. We demonstrate that this approach yields precise quantification of T-cell iron content through a physiological range.

References

1. Frost J.N. et al., Med. 2021, 2, 164-179

2. Malesza I.J. et al., Nutrients, 2022, 14, 3478

3. Prentice A.M. et al., Food Nutr. Bull., 2007, 28, S524-539