Albumin enhances chlamydial infectivity on human placental cells.

Chlamydia trachomatis (L2) adhere to and infect chorionic membrane in vitro. Similarly, chlamydiae pre-exposed to either chorion homogenate, newborn calf serum or pure bovine serum albumin display a higher infectivity against mouse fibroblast cells in vitro. Polyacrylamide gel electrophoresis of the chorion homogenate displays a peptide band which co-migrates with albumin. Isolated chlamydiae stripped of protein with trypsin and exposed to albumin-containing solutions are precipitated by both anti-chlamydia and anti-albumin antibody. These findings suggest that albumin may selectively adhere to the surface of chlamydiae and serve an intermediary role in the infectious process.