Faulty immune memory can trigger cold sores, cancer

A faulty immune memory can trigger infections that may lead to cold sores and even cancer in some people, say researchers.

The memory circuit, identified by the research team, involves a gene and protein called DOCK8, which helps white blood cells form synapses, tiny points of cell contact, that are responsible for memory in the brain.

An increased understanding of immune memory would not only lead to enhanced vaccines but also improve the treatment of cancer, transplant rejection, auto-immunity and allergies.

"Vaccines that provoke long-lasting immunity are among the greatest advances delivered by health research, but the circuits that determine whether they work or not have been among the most difficult to decipher," said Chris Goodnow from the John Curtin School of Medical Research in Australia and co-leader of the research team.

Lapses of immunological memory also explain the reactivation of infections responsible for cold sores, shingles, yeast infections, and possibly some forms of cancer.

Katrina Randall, clinical immunologist and co-research team leader said: "Immunity normally lasts for years after we are immunised or infected because our immune system remembers the shape and 'fingerprints' of an infecting microbe..."

"When immunological memory wanes we become susceptible to infection again. For some vaccines like the tetanus vaccine this occurs after several years, and for many experimental vaccines their memory has so far proved just too short to be useful."

The findings were published in the latest issue of Nature Immunology.