Multiple myeloma patients display weakened antibody responses to mRNA COVID vaccines

Weakened antibody responses to COVID-19 mRNA vaccines among most patients with multiple Read more

Precision medicine with multiple myeloma

“Precision medicine” is an anti-cancer treatment strategy in which doctors use genetic or other tests to identify vulnerabilities in an individual’s cancer subtype. Winship Cancer Institute researchers have been figuring out how to apply this strategy to multiple myeloma, with respect to one promising drug called venetoclax, in a way that can benefit the most patients. Known commercially as Venclexta, venetoclax is already FDA-approved for some forms of leukemia and lymphoma. Researchers had observed that multiple Read more

Promiscuous protein droplets regulate immune gene activity

Biochemists at Emory are achieving insights into how an important regulator of the immune system switches its function, based on its orientation and local environment. New research demonstrates that the glucocorticoid receptor (or GR) forms droplets or “condensates” that change form, depending on its available partners. The inside of a cell is like a crowded nightclub or party, with enzymes and other proteins searching out prospective partners. The GR is particularly well-connected and promiscuous, and Read more

Georgia Tech/Emory Center for Regenerative Medicine

CV cell therapy: bridge between nurse and building block

In the field of cell therapy for cardiovascular diseases, researchers see two main ways that the cells can provide benefits:

*As building blocks – actually replacing dead cells in damaged tissues

*As nurses — supplying growth factors and other supportive signals, but not becoming part of damaged tissues

Tension between these two roles arises partly from the source of the cells.

Many clinical trials have used bone marrow-derived cells, and the benefits here appear to come mostly from the “paracrine” nurse function. A more ambitious approach is to use progenitor-type cells, which may have to come from iPS cells or cardiac stem cells isolated via biopsy-like procedures. These cells may have a better chance of actually becoming part of the damaged tissue’s muscles or blood vessels, but they are more difficult to obtain and engineer.

A related concern: available evidence suggests introduced cells – no matter if they are primarily serving as nurses or building blocks — don’t survive or even stay in their target tissue for long.

Transplanted cells were labeled with a red dye, while a perfused green dye shows the extent of functional blood vessels. Blue is DAPI, staining nuclear DNA. Yellow arrows indicate where red cells appear to contribute to blood vessels.

Transplanted cells were labeled with a red dye, while a perfused green dye shows the extent of functional blood vessels. Blue is DAPI, staining nuclear DNA. Yellow arrows indicate where red cells appear to contribute to green blood vessels. Courtesy of Sangho Lee.

Stem cell biologist Young-sup Yoon and colleagues recently published a paper in Biomaterials in which the authors use chitosan, a gel-like carbohydrate material obtained by processing crustacean shells, to aid in cell retention and survival. Ravi Bellamkonda’s lab at Georgia Tech contributed to the paper.

More refinement of these approaches are necessary before clinical use,  but it illustrates how engineered mixtures of progenitor cells and supportive materials are becoming increasingly sophisticated and complicated.

The chitosan gel resembles the alginate material used to encapsulate cells by the Taylor lab. Yoon’s team was testing efficacy in a hindlimb ischemia model, in which a mouse’s leg is deprived of blood. This situation is analogous to peripheral artery disease, and the readout of success is the ability of experimental treatments to regrow capillaries in the damaged leg.

The current paper builds a bridge between the nurse and building block approaches, because the researchers mix two complementary types of cells: an angiogenic one derived from bone marrow cells that expands existing blood vessels, and a vasculogenic one derived from embryonic stem cells that drives formation of new blood vessels. Note: embryonic stem cells were of mouse origin, not human. Read more

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Stem cell research center gets NSF support

Stem cell research is on the verge of impacting many elements of medicine, but scientists haven’t yet worked out the processes needed to manufacture sufficient quantities of stem cells for diagnostic and therapeutic purposes.

Todd McDevitt and Robert Nerem

The National Science Foundation (NSF) has awarded $3 million to Georgia Tech to fund a center that will develop engineering methods for stem cell production. The program’s co-leaders are Todd McDevitt, PhD, an associate professor in the Georgia Tech/Emory Department of Biomedical Engineering and Robert Nerem, director of the Emory/Georgia Tech Center for Regenerative Medicine (GTEC), which will administer the award.

“Successfully integrating knowledge of stem cell biology with bioprocess engineering and process development is the challenging goal of this program,” says McDevitt.

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