A new study explores why some extremely rare cases of human papilloma virus (HPV) infections cause horn-like growths on the skin, a condition known as tree-man syndrome.
Infection with HPV is extremely common, with most people catching it at some point and not even being aware of it due to a robust immune response, though some may experience skin or genital warts. Why only a handful of individuals react to it by developing tree-man syndrome was not well understood.
To find out why this strikes a handful and not others, Rockefeller’s Jean-Laurent Casanova examines the genetics of an otherwise healthy patient who contracted a severe case of tree-man syndrome and several family members who exhibited milder reactions to HPV. Casanova’s team identified a mutation that affects one’s reaction to HPV by decreasing the production of CD28, a molecule within the immune system that plays an important role in activating pathogen-fighting T cells.
Given the purported importance of CD28 to the immune system, the scientists were surprised that this CD28-deficient individual was healthy prior to contracting tree-man syndrome. “CD28 is thought of as a pillar of T cell immunity,” says Casanova. “The fact that this patient was otherwise healthy suggests that CD28 is largely redundant in human health. Something else is able to step up to provide protection against other infections.”
The findings, published in Cell, form a small part of Casanova’s larger work, which continues to demonstrate that the severity of influenza, tuberculosis, COVID, and other diseases, is not solely dependent on the pathogen itself, but on genetics of the host, too.
Source: Rockerfeller University
