We first introduce a generalization of the Bernoulli polynomials,
and consequently of the Bernoulli numbers, starting from suitable
generating functions related to a class of Mittag-Leffler
functions. Furthermore, multidimensional extensions of the
Bernoulli and Appell polynomials are derived generalizing the
relevant generating functions, and using the Hermite-Kampé de
Fériet (or Gould-Hopper) polynomials. The main properties of
these polynomial sets are shown. In particular, the differential
equations can be constructed by means of the factorization method.