Abstract:
Tuberculosis (TB) is the first cause of death by a single infectious agent. Previous
reports have highlighted the presence of platelets within Tb granulomas, albeit the
immune-associated platelet response to Mycobacterium tuberculosis (Mtb) has not
be deeply studied. Our results showed that platelets are recruited into the granuloma
in the late stages of tuberculosis. Furthermore, electron-microscopy studies showed
that platelets can internalize Mtb and produce host defense peptides (HDPs), such
as RNase 7, HBD2 and hPF-4 that bind to the internalized Mtb. Mtb-infected platelets
exhibited higher transcription and secretion of IL-1ß and TNF-α, whereas IL-10 and
IL-6 protein levels decreased. These results suggest that platelets participate in the
immune response against Mtb through HDPs and cytokines production.