Researchers Identify New Type of Lung Cell

A research team led by Boston University scientists has identified a new type of lung cell that is implicated in the body’s immune defense against pneumonia-causing bacteria.

Immunohistochemical analysis of a human lung section stained with anti-PIWIL4 antibody. Scale bars – 10 ?m. Image credit: Wasserman et al, doi: 10.1172/JCI94639.

There are two classifications of cells in the human body: germ cells that are used to make sperm and eggs and somatic cells that make up every other cell in the body including lung cells.

There are widespread differences between germ cells and somatic cells underscoring their markedly different roles in human biology.

It was previously thought that a gene called MIWI2 (also known as the Piwi like RNA-mediated gene silencing 4, or PIWIL4) was only expressed in male germ cells as part of a family of genes that ensure the proper development of sperm.

However, Dr. Matthew Jones, an assistant professor of medicine at Boston University School of Medicine, and his co-authors from the United Kingdom and the United States have discovered that not only is the same gene expressed in somatic cells in the body, but also marks a distinct population of multi-ciliated cells that line the upper airways of the lung.

“These ciliated cells have hair-like projections that function to sweep mucous and other foreign material out of the lung,” Dr. Jones explained.

“However, what sets this new population of ciliated cells apart is that they express the MIWI2 protein and in this report, were found to have a specialized role in controlling lung infection.”

Published in the Journal of Clinical Investigation, the findings may lead to new, non-traditional approaches in the fight against pneumonia and chronic lung diseases.

“The new cell type and pattern of gene expression may also lead to a better understanding of the mechanisms behind diseases like COPD and asthma,” the researchers said.

“We are hopeful next steps will lead to new ways of investigating how the body reacts to infectious bacteria in the lung.”

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Gregory A. Wasserman et al. Expression of Piwi protein MIWI2 defines a distinct population of multiciliated cells. J Clin Invest, published online September 18, 2017; doi: 10.1172/JCI94639