Immunity system complexity: killer T cells promote repair (Introduction)

by David Turell , Tuesday, January 16, 2024, 20:40 (102 days ago) @ David Turell

They produce guiding molecules:

https://medicalxpress.com/news/2024-01-killer-cells-tissue-regeneration.html

"One of the main functions of the immune system is to defend the body against infections or cancer. This task is efficiently carried out by immune cells known as killer T cells. These cells possess the ability to destroy body cells that are, for example, infected by viruses or transformed into tumor cells. However, what happens after the destruction of infected body cells? How is tissue damage, resulting from the destruction of target cells, repaired, and organ function restored?

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"'This indicates that soluble factors produced by killer T cells during the destruction of infected cells support the healing of the remaining tissue cells," explains author Lisa Schmidleithner.

"Which factors mediate this surprising healing property? The authors found that growth factors such as amphiregulin are involved in the wound healing effect. Human killer T cells can produce these growth factors and stimulate other cells in the tissue to produce them as well. In addition to these growth factors, "classic" immune messengers such as tumor necrosis factor and interferon-gamma can enhance the impact of amphiregulin and support the wound healing effect.

"To better understand the impact of the regenerative effects of killer T cells, the researchers co-cultured human mini-organs, called organoids, with killer T cells.

"'We observed that the number and size of these organoids significantly increased when activated killer T cells or their released growth factors were present," reports author Philipp Stüve. This suggests that killer T cell-mediated wound healing processes can influence complex regeneration processes.

"In addition to these positive effects on tissue regeneration and wound healing, the same killer T cell-derived growth factors could potentially promote diseases such as cancer. "Indeed, in further experiments, we observed that factors produced by activated killer T cells also enhanced the growth of tumor cells," reports Malte Simon, who also authored the study.

"What do these results mean for further research?

"'Our data suggest that killer T cells not only destroy pathologically altered cells but also initiate the subsequent tissue regeneration," explains Markus Feuerer, the lead author of the study. This mechanism could be useful in the context of viral infections to promote wound closure after the destruction of infected cells and thus restore functionality of the tissue. However, in the context of tumor diseases, this could promote the growth of undestroyed tumor cells."

Comment: from a design point of view, the work of killer T cells is destructive. Therefore, it is reasonable to add a reconstructive function to follow. All of evolution makes sense from a purposive design view.