  We measure the evolution of the galaxy Luminosity Function as a function of
large-scale environment up to z=1.5 from the VIMOS-VLT Deep Survey (VVDS) first
epoch data. The 3D galaxy density field is reconstructed using a sample of 6582
galaxies with 17.5 < I_{AB} < 24 and measured spectroscopic redshifts. We split
the sample in four redshift bins up to z=1.5 and in under-dense and over-dense
environments according to the average density contrast \delta=0. There is a
strong dependence of the Luminosity Function (LF) with large-scale environment
up to z=1.2: the LF shape is observed to have a steeper slope in under-dense
environments. We find a continuous brightening of \Delta M* ~0.6 mag from
z=0.25 to z=1.5 both in under-dense and over-dense environments. The rest-frame
B-band luminosity density continuously increases in under-dense environments
from z=0.25 to z=1.5 whereas its evolution in over-dense environments presents
a peak at z~0.9. We interpret the peak by a complex interplay between the
decrease of the star formation rate and the increasing fraction of galaxies at
\delta>0 due to hierarchical growth of structures. As the environmental
dependency of the LF shape is already present at least up to z=1.2, we
therefore conclude that either the shape of the LF is imprinted very early on
in the life of the Universe, a `nature' process, or that `nurture' physical
processes shaping up environment relation have already been efficient earlier
than a look-back time corresponding to 30% of the current age of the Universe.
