The journey of a marathon sleeper

A marathon sleeper who got away left some clues for Emory and University of Florida scientists to Read more

A push for reproducibility in biomedical research

At Emory, several scientists are making greater efforts to push forward to improve scientific research and combat what is being called “the reproducibility crisis.” Guest post from Erica Read more

Exosomes as potential biomarkers of radiation exposure

Exosomes = potential biomarkers of radiation in the Read more

variable lymphocyte receptor

Lampreys and the reverse spy problem

Call it the reverse spy problem. If you were a spy who wanted to gain access to a top secret weapons factory, your task would be to fit in. The details of your employee badge, for example, should look just right.

As described in this 2016 JCI Insight paper, Emory and University of Toronto investigators wanted to do the opposite. They were aiming to develop antibody tools for studying and manipulating plasma cells, which are the immune system’s weapons factories, where antibody production takes place. The situation is flipped when we’re talking about antibodies. Here, the goal is to stand out.

Do these guys look like good spies?

Monoclonal antibodies are classic biomedical tools (and important anticancer drugs). But it’s tricky to develop antibodies against the places where antibodies themselves are made, because of the way the immune system develops. To guard against autoimmune disease, antibodies that would react against substances in the body are often edited out.

To get around this obstacle, researchers used organisms that have very different immune systems from humans: lampreys. Emory’s Max Cooper and colleagues had already shown how lampreys have molecules — variable lymphocyte receptors or VLRs — that function like antibodies, but don’t look like them, in terms of their molecular structure.

From the paper:

We reasoned that the unique protein architecture of VLR Abs and the great evolutionary distance between lampreys and humans would allow the production of novel VLRB Abs against biomedically relevant antigens against which conventional Abs are not readily produced because of structural or tolerogenic constraints.

Senior author Goetz Ehrhardt, now at University of Toronto, used to be in Cooper’s lab, and their two labs worked together on the JCI Insight paper. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Alternative antibody architecture

This complex diagram, showing the gene segments that encode lamprey variable lymphocyte receptors, comes from a recent PNAS paper published by Emory’s Max Cooper and his colleagues along with collaborators from Germany led by Thomas Boehm. Lampreys have molecules that resemble our antibodies in function, but they look very different at the protein level. The study of lamprey immunity provides hints to how the vertebrate immune system has evolved.
PNAS-2014-Das-1415580111_Page_4

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Lampreys hint at origin of ancient immune cells

Lamprey slideStudying lampreys allows biologists to envision the evolutionary past, because they represent an early offshoot of the evolutionary tree, before sharks and fish. Despite their inconspicuous appearance, lampreys have a sophisticated immune system with three types of white blood cell that resemble our B and T cells, researchers have discovered.

Scientists at Emory University School of Medicine and the Max Planck Institute of Immunology and Epigenetics in Freiburg have identified a type of white blood cell in lampreys analogous to the “gamma delta T cells” found in mammals, birds and fish. Gamma delta T cells have specialized roles defending the integrity of the skin and intestines, among other functions.

The results are published in the journal Nature. The finding follows an earlier study showing that cells resembling two main types of white blood cells, B cells and T cells, are present in lampreys.

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Posted on by Quinn Eastman in Immunology Leave a comment