There are many types of T cells, which help us fight pathogens. New research has shown that a type of T cell that stays in the intestinal tissue, also known as a tissue resident lymphocyte, uses sugar as fuel. These cells, which are specifically called intestinal intraepithelial lymphocytes (IELs), can monitor for invaders and react when necessary. This study has also shown that the metabolic processes in the IELs are faster than what is seen in lymphocytes that circulate throughout the body.
A healthy body is better at fighting infection, and this research may provide one explanation; when there is an appropriate supply of sugar in the gut, it may boost the activity of tissue resident lymphocytes in the local area, and lead to a more rapid elimination of infection. The findings have been reported in the Proceedings of the National Academy of Sciences (PNAS).
While various lymphocytes can be found throughout the body, tissue resident lymphocytes stay in one kind of tissue and adapt to their local environment. The IELs are adapted to the intestinal wall.
"Circulating lymphocytes spend most their lifetime in the lymph nodes, where there is high availability of energy. It's as if the lymph nodes are filled with lunch boxes. These cells can be permanently filled with energy, and even grab a box to go when they leave the lymph nodes to circulate through the body," explained study leader and Associate Professor Marc Veldhoen of the Instituto de Medicina Molecular João Lobo Antunes (iMM) and the Faculdade de Medicina de Lisboa (FMUL).
In this study, a mouse model was exposed to infection. The researchers found that the activation of resident lymphocytes in the gut, and the time it took for infections to clear depended on how much sugar was available.
Tissue resident lymphocytes don't have access to the same level of energy as circulating lymphocytes, and they stay in a constant state of partial activation. These resident cells are prepared to react to issues like infections, they adapt to the gut environment, and they can control their metabolic activity depending on how much glucose is available, added Veldhoen.
Resident lymphocytes in the gut can generate energy faster than lymphocytes in circulation. "The glucose is rapidly taken [up] by these cells to generate lactate or pyruvate, molecules that are used to produce energy," added study co-author Vanessa Morais, a group leader at iMM.
While more research will be needed to confirm these findings in humans, it highlights the importance of a balanced diet.