Surfactant protein A: an immunoregulatory molecule involved in female reproductive biology.

Surfactant protein A (SP-A), a member of the collectin family originally described as a major component of lung surfactant, plays an important role in the modulation of lung host defense. A new interest in SP-A is provided by the link between fetal lung development and the timing of labor in the mouse. In the present review, we discuss some of the known features of SP-A such as biological functions, signaling pathways involved and the recent developments showing that SP-A bind and serve as a signal in the female genital tract. Therefore, such reports support a new paradigm involving SP-A as a multifunctional protein in the parturition process.