Antagonists to chaperonin 10

Antibodies raised against recombinant or synthetic cpn10 are disclosed. The cpn10 has the sequence GSMAGQAFRKFLPLFDRVLVERSAAETVTKGGIMLPEKSQGKVLQ ATVEAVGSGSKGKGGEIQPVSVKEGDKVLLPEYGGTKVVLDDKDYFLFRDGDIL GKYVD (SEQ ID NO:). Antibodies are raised against either the entire sequence of cpn or a shorter peptide sequence derived from cpn such as Ac-AGQAFRKFLPL (SEQ ID NO:), ACQAFRKFLPL (SEQ ID NO ), or EKSQGKVLQAT (SEQ ID NO:), in which the peptides may have a single amino acid deletion, addition or substitution. The antibodies can be used to terminate pregnancy, suppress tumor cell growth or enhance the immune system.