A body’s immune system is often considered as the main line of defense against pathogens and other harmful microorganisms. The cells of the immune system need to rapidly move through the bloodstream to the affected targets in order to tackle such microorganisms. The helper T cells from the immune system flowing towards the affected body part are a kind of primary defense mechanism acting against diseases. While these cells get ready for navigation, their path is not quite smooth; rather the bloodstream is significantly chaotic for the cells to pass easily through their course. As a response to this situation, the T cells have developed certain mechanisms which enable them to move easily.

Through a Chaotic Blood Stream Environment

An extensive study on the flow of immune system cells was carried out by a group of researchers, headed by researcher Klaus Ley, M.D. from the La Jolla Institute for Allergy and Immunology. The results of this study indicate that mature helper T cells use membrane protrusions to gain traction along the vasculature. To record these observations, high-resolution microscopes were used along with a fluorescent marker to identify the cells. Using this technique, videos of good clarity were obtained that showed distinct T cells moving across muscles as well as artificial surfaces.

Such an in-depth study made it possible to view how exactly the cells used tethers in the form of membranes. These membranes were repeatedly cast out by the cells in the forward direction to gain traction. As bloodstreams are mainly characterized by heavy fluid flow, the mature T cells were observed to put across multiple membranes for getting a firm grip.

From this study, it was observed that in contrast to the fully grown T cells, the immature ones did not have any protrusions and membranes, which caused them to roll improperly along the surfaces. Rather, according to professor Ley from the LJI’s Division of Inflammation Biology, the immature T cells need to grow certain biomechanical properties that could turn out to be useful for their movement.