According to a study published in Science X-Press, an advanced, online edition of the journal Science on Sept. 14, a single gene immunodeficiency may cause susceptibility to herpes simplex virus. This suggestion is contradictory to the current scientific theory of how genes function in vulnerability to infections. These findings may be relevant in other infectious diseases also.

In the study, scientists focused on blood cells from two French children with a deficiency for UNC-93B, an endoplasmic reticulum protein involved in the recognition of pathogens. When infected with herpes simplex virus-1, the UNC-93B-deficient cells were unable to produce natural interferons alpha, beta, and gamma (IFNs á, â and ã). Interferons are produced by the immune system to fight infections and tumors.

This deficiency resulted in high rates of herpes simplex virus-1 proliferation and cell death. Assuming these findings extend to neurons, they provide a plausible mechanism for herpes simplex encephalitis.

"We and our colleagues have identified recessive UNC-93B deficiency as a genetic etiology of herpes simplex encephalitis in otherwise healtalpha, ihy patients," said Professor Bruce Beutler, M.D., one of three Scripps Research scientists who contributed to the study. "The discovery of this genetic cause for herpes simplex encephalitis not only broadens our understanding of these types of immunodeficiencies, but also has important therapeutic implications-some of these patients could benefit from recombinant interferon alpha (IFN- á) treatment, just as patients with low levels of naturally occurring interferon gamma (IFN- ã) benefit from a similar life-saving approach."