Individuals with Hermansky-Pudlak syndrome type 2 (HPS2) are albinos with prolonged bleeding times and increased susceptibility to infections. Patients with HPS2 have mutations in a protein called AP-3, which is involved in directing the movement of proteins inside cells. How mutations in this protein lead to immunodeficiency, however, is unclear. In the November issue of Nature Immunology, scientists show that AP-3 is required by T cells to kill infected cells.
Gillian Griffiths and colleagues from Oxford University found that AP-3–deficient T cells taken from a patient with HSP-2 could not kill target cells. Closer analysis showed that lytic granules, which are required for killing, fail to move towards the contact site between the T cell and target cell. AP-3 therefore appears to be involved in mediating granule movement inside killer T cells.
Gillian M. Griffiths
University of Oxford, UK
Tel: +44 1865 275 571
Additional contact for comment on paper:
Jonathan W. Yewdell
NIAID, National Institutes of Health
Tel: +1 301 402 4602
Also available online.
(C) Nature Immunology press release.
Message posted by: Trevor M. D'Souza