The role of heat shock proteins in reproduction

Heat shock proteins (hsp) were first discovered in cells exposed to elevated temperature. They are preferentially expressed in response to an array of insults, including hyperthermia, free oxygen radicals, heavy metals, inflammation and infection. In addition hsp are involved in several processes essential for cellular function under physiological conditions. Heat shock proteins are expressed during oogenesis and spermatogenesis. In the early stages of the pregnancy they are expressed both in embryo and maternal decidua. Antibodies to bacterial and human hsp are present at high titers in serum of many patients undergoing in vitro fertilization. Several studies provided evidence that immune sensitization to hsp is associated with unsuccessful embryo development and implantation failure in in-vitro-fertilization (IVF) patients.