Entry of Newcastle disease virus into host cells: an interplay among viral and host factors

Newcastle disease (ND) is a major burden for the poultry industry worldwide, especially in developing countries. The virus that causes this disease, Newcastle disease virus (NDV), is also an effective vector for the development of novel human and animal vaccines and a promising oncolytic virus for cancer therapy. The mechanism of entry of NDV into host cells is of particular interest because it has a significant impact on the infectivity, host range, and pathogenicity of the virus. Here, we present an overview of the entry of NDV into cells, focusing on the interplay among viral and host factors involved in this process. In particular, recent research revealing novel features of NDV attachment to cells, the identification of viral and cellular components that regulate binding of the virus to cells, and the emerging role of novel cellular routes of NDV entry are discussed. More importantly, some of the remaining gaps in our understanding of NDV entry and some fundamental questions for research efforts in the future are also highlighted.