Tag Archives: allergies

5 Amazing Feats Performed by “Meta-Genes”

[Image via the NIH Image Gallery. Photo by Alex Ritter, Jennifer Lippincott Schwartz, and Gillian Griffiths. Full video, complete with narration here.] 

Under the Radar: A series of listicles about biology concepts you definitely won’t find in newspaper headlines.

#1: Be a Navigation App for Immune Cells

Natural killer cells, or “NK cells” are the human body’s best defense against cancer.  While other types of immune cells often ignore tumor cells, natural killer cells specialize in finding and destroying human cells that look either infected or like cancer mutants. In leukemia patients,  a higher number of active natural killer cells ups the patient’s chances for survival, so much so that  researchers are experimenting with transfusing NK cells into patients.

Just one problem there: Active natural killer cells die without a strong support network.

Dormant NK cells can survive in the bloodstream for a long time, but once activated, natural killers have to make a b-line for cells carrying a marker called IL-15 or die,  but until a study in Monday’s edtion of PNAS , no one knew how natural killers knew to look for IL-15. The study, led by Vanderbilt immunologist Eric Sebzda and grad student Whitney Rabacal, traced NK cells’ IL-15 homing ability back to a biochemical with the horrendous name “Kruppel-like Factor 2” (KLF2).

KLF2, oddly enough, also exerts a strong navigational influence on the immune system’s T-cells and B-cells.  Even though all three types of cells fall under the “white blood cell” umbrella, the notion that one protein could control navigation in all three is pretty weird.  Crawling and navigating are complex tasks, requiring coordination between dozens of genes. “[NK cell migration] is totally different from how t-cells and b-cells circulate,” Sebzda said.

Additionally, taking away KLF2 has distinctive effects on each type of cell: KLF2-less t-cells vacate the central body and crawl out to lab mice’s fingers and toes, KLF2-less b-cells all congregate at the spleen (which creates some serious problems for those lab mice), and KLF2-less natural killers end up dying alone.

So KLF2 could be super-useful for improving cancer immunotherapy. But why is KLF2 so versatile in the first place?

The answer lies in KLF2’s ability to bind to a certain recurring DNA base pair sequence, one that presumably earmarks the genes needed in each immune system navigation system, and it’s far from the only protein with such abilities…

Continue reading “5 Amazing Feats Performed by “Meta-Genes”” »

Epidemic of Absence: A book that made me think too much

What it’s about:

Moises Velasquez-Manoff’s Epidemic of Absence tackles one of the trickiest and trendiest topics in 21st-century biomedical research: the complex relationship between autoimmune disease and the bacteria that live in our guts.

A growing body of evidence suggests that by decimating the number of pathogenic microbes people are exposed to, modern medicine has inadvertently shifted the ecological balance between the human immune system and the human microbiome, leaving millions of people vulnerable to allergies and autoimmune disease.

The basic evolutionary argument is that our immune system evolved to cope with a constant onslaught of opportunistic microbes by developing a complex system of checks-and-balances with our bodies’ microbial populations. With those microbes gone, many of the immune system’s coping strategies are having disastrous side effects. In this book, Velasquez-Manoff implicates the depletion of bacterial biodiversity as a driving agent in the pretty much every non-infectious disease you can think of (cancer, depression, Crohn’s, Celiac’s, allergies, and autism are all covered in this book).

The Upsides:

It’s a rare snapshot of a scientific revolution in progress. And it’s easily the most thought-provoking book I’ve read all year. Continue reading “Epidemic of Absence: A book that made me think too much” »