proteins impair mouse embryo development in vitro

Two-cell mouse embryos (B6D2F1) were cultured in the presence or absence of 100 mg/ml monoclonal antibodies specific for the mammalian 60 kDa (HSP60), 70 kDa (HSP70) and 90 kDa (HSP90) heat shock proteins. Embryo development was evaluated after 3, 5 and 7 days in culture by determining the number of blastocysts, hatched blastocysts and outgrown trophoblasts at the successive time points. At day 3, only 29 % (22/75) of the embryos cultured with anti-HSP60 antibody developed to the blasto-cyst stage (P, 0.0001) as compared to 67 % (31/46) of the embryos cultured with anti-HSP70, 72 % (43/60) cultured with anti-HSP90, and 79 % (49/62) in medium plus mouse IgG1. By day 5, hatched embryos were present in 28 % (13/ 46) of the cultures containing anti-HSP70 (P, 0.0001), as opposed to 57 % (34/60) containing anti-HSP90 and 73% (45/62) containing IgG1. At day 7, outgrown trophoblasts were observed in 9 % (4/46) of cultures containing anti-HSP70 (P, 0.0001), 45 % (27/60) containing anti-HSP90 (P, 0.01) and 66 % (41/62) cultured in medium plus IgG1. Antibodies to different heat shock proteins exerted a detrimental effect on mouse embryo development at unique development stages. Immune sensitization to heat shock proteins may be a cause of reproductive failure. Key words: embryo development/heat shock proteins/mouse/ preimplantation embryo/reproductive failur