[4] Some bacteria, such as Mycoplasma pneumoniae, a pathogen of the respiratory tract, may display multinuclear filaments as a result of a delay between genome replication and cellular division.
[10] Syncytia are multinuclear cells that can form either through normal biological processes, such as the mammalian placenta, or under the influence of certain pathogens, such as HIV, via fusion of the plasma membrane.
[13] The polymorphonuclear leukocytes of mammals are not polynuclear cells, although the lobes of their nuclei are so deeply bifurcated that they can appear so under non-optimal microscopy.
This syncytia is called plasmodium, in the sense of a multinucleate protoplast without a cell wall which exhibits amoeboid movement.
[16] In addition to performing simple interface duties, the placental syncytia also acts as a barrier to infection from viruses, bacteria, and protozoa, which is likely due to unique cytoskeletal properties of these cells.
[17] This interaction is likely specific to CD4+ T-cells, as cells lacking this receptor were unable to form syncytia in laboratory conditions.