The trophoblast is an important component of the placenta, and it
is able to recognize and respond to microorganisms and their
products through the expression of TLRs (30–32). TLRs are a family
of innate immune receptors that have an essential role in the recognition
of pathogen-associated molecular patterns (33–35). Trophoblasts
are able to produce cytokines/chemokines and antiviral
factors following TLR-3 ligation in vitro, suggesting the potentially
active role of these cells in the control of viral infections (20, 36).
Some of these receptors (chemokine and TLRs) may also function
as viral receptors mediating viral recognition and entry into the