This research project was a collaboration between Dr. Selleri and her colleagues, and Rockefeller University's Dr. Jean-Laurent Casanova, professor in the St. Giles Laboratory of Human Genetics of Infectious Diseases. Dr. Casanova had led a previous study describing 20 ICA patients, of which most children suffered their first serious infection by age one, and nine died of an invasive pneumonia.
Dr. Selleri has long been studying congenital asplenia in the laboratory using the mouse as a model system and had previously discovered that a transcription factor known as Pbx is the prime regulator of spleen development in mouse models. Dr. Matthew Koss, a recent Ph.D. graduate who had studied in Dr. Selleri's lab, led the effort to create a strain of mice that lacked Pbx in the spleen, and were born without a spleen. He identified a regulatory module that is controlled by Pbx and targets Nkx2.5, a gene downstream of Pbx, in the developing spleen of the mouse embryo. He also discovered that Pbx controls the growth of the spleen by directly regulating the expression of Nkx2.5, which in turn controls cell proliferation within the primitive spleen organ.
Then, in Dr. Casanova's lab, Alexandre Bolze, a graduate student, sequenced genetic samples from ICA patients and analyzed them using whole exome sequencing technology, which allows sequencing of the entire coding genome of multiple patients -- a technique routinely employed by Dr. Casanova. Bolze found that Nkx2.5 was mutated in a family of asplenic patients, some of which died from lethal infections -- confirming the importance of Nkx2.5 in human congenital asplenia as in the mouse model of the disorder.
"This study illustrates the unique strength in using mouse models and human genetics hand-in-hand," sa
|Contact: Lauren Woods|
New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College