Hck is required for extracellular vesicle
(EV)-associated secretion of ADAM17. (a–b) Hck is present in HIV pEV. (A)
Blotting of Hck and indicated tyrosine kinases in pEV purified by differential
centrifugation (from 2 ml plasma) from 2 non-viremic HIV
patients (HIV.07/0.08) and one healthy control (cont.02). For blotting control
the tyrosine kinases were transiently expressed in 293T cells. (b) Blotting of
Hck, Yes and Nef in pEV from HIV.08 and a healthy donor (cont.03) isolated by
anti-αvβ3-coupled magnetic beads. For blotting control lysates from NIH3T3 and
293T cells transfected with ADAM17 and Nef were used. Beads: bead-isolated pEV;
FT: flow through. (c–e) Nef-activated Hck correlates with ADAM17 activation. (c)
Blotting of indicated factors in lysates of transiently transfected 293T cells.
NAKC: Nef-associated kinase complex (hnRNPK, Lck, PKCδ). (d) Immunoprecipitation
of Hck from transiently transfected 293T cells as indicated, and blotting for
p-Src. (e) Blotting of indicated factors in lysates of 293T cells stably
expressing (stbl. exp.) p59 Hck, and transiently transfected (trans. transf.) as
indicated (lower four panels). EV purified from the supernatants were blotted
for ADAM17 and Tsg101 (upper two panels). (f–m) EV-associated ADAM17 secretion
from myeloid cells requires Hck. (f) Blotting of indicated factors in lysates of
immature and mature dendritic cells (iDC/mDC). (g) Blotting of indicated factors
in lysates of iDC and mDC, treated/not treated with the tyrosine kinase
inhibitor PP2. (h) Blotting of indicated factors in lysates of iDC, mDC, Jurkat
and 293T cells, transiently transfected as indicated, or untreated (mDC). (j)
Immunoprecipitation of Hck from Nef-transfected iDC and mDC and blotting for
indicated factors. (k) Same experiment as shown in (H), blotting EV purified
from culture supernatants for indicated factors. (l) Blotting of indicated
factors in lysates of Nef-transfected macrophages. (m) Same experiment as shown
in (l), blotting EV purified from culture supernatants. Colored boxes in all
panels depict results that are described in the text.