Complexes Of Trophoblastic Peptides And Heat Shock Protein 70 As A Novel Contraceptive Vaccine In A Mouse Model

Objectives: The idea of contraceptive vaccines has interested reproductive biologists and immunologists for nearly two decades, yet there is currently no approved approach. The placenta might be a promising target for gestation termination and contraception. In this study, we try to explore a new immunocontraceptive vaccine, which utilizes HSP70-trophoblastic peptide complexes to generate a specific T cell immune response against placental trophoblasts.Methods: 1. In vitro experiments:HSP70-peptide complexes co-cultured with splenic T cells with control groups.(1) Observation of T cell proliferation and cytokine IL-2 and IFN-? levels.(2) By comparing the trophoblast cells antigenic peptides and immune-induced with different tissues-derived peptide, observe whether the activation of t cells with trophoblastic specificity.(3) By detecting UTY and SMCY genes, find out male or female derived trophoblasts,prepare corresponding peptide respectively to activate the proliferation of T cells, detecting cytotoxicity of two kinds of T-cells on trophoblasts, determine what components are capable of inducing trophoblast T cell activation as described above.2. Animal models:(1) Mice were injected subcutaneously with Hsp70- trophoblastic peptide, with control groups. 7 days after the separation of mouse spleen T cells by RT-PCR and real-time PCR to detect the expression of cytokines.(2)The female BALB / c mice were inoculated HSP70- trophoblastic peptide complex, then mated with BALB / c male mate, a control group was observed to see whether HSP70-trophoblastic peptide complex have immunocontraceptive effects.3. Placental trophoblast cells were isolated from full-term(38 weeks) pregnant human female(N = 6), HSP70 peptide complex is used for stimulating autologous T cells, a control group was observed to see whether cytokine IFN-? and IL-2 proliferate.Results:1. We demonstrated that trophoblast-derived peptides, after in vitro binding with HSP70, can activate T cells both in vitro and in vivo.2. The activated T cells have a Th1 bias and specifically cytolysis trophoblasts, thus leading to pregnant failure.3. Such activated T cells seem to have an effect on the early gestation, rather than influence the preimplantation.4. We did not observe the side effect of such vaccine in mice.Conclusion:We describe a novel contraceptive strategy which utilizes HSP70-trophoblast peptide complexes to induce the T cell-specific immune attack against trophoblasts, leading to contraception...