Discovery of novel genetic mechanism of immune deficiency
Magdalena M. Gorska and Rafeul Alam of National Jewish Health have discovered a novel genetic mechanism of immune deficiency. They had previously identified Unc119, a signaling protein that activates T cell proliferation, as an activator of SRC-type tyrosine kinases, regulators of cellular function. Other researches had linked idiopathic CD4 lymphopenia, a rare immune disorder defined by low levels of CD4 T cells, to reduced activation of the SRC-type kinase known as Lck, which is involved in T cell development and proliferation. During the study, the researchers examined three patients who came to National Jewish Health with CD4 lymphopenia. Researchers sequenced their Unc119 gene and those of several patients who suffered low CD4 T cell counts. One patient had a mutation in her Unc119 gene which was not present in other lymphopenia patients nor in any genetic database. The mutation prevented Lck activation and its downstream signaling, reducing the proliferation of T cells.