Use of immunogenic immunosuppressive and/or angiogenic proteins which have been rendered inactive, process for their preparation and pharmaceutical or vaccinal uses

A method for inhibiting the proliferation of cancer cells in a patient, comprising:

• inactivating a polypeptide that is a soluble factor which is released or induced by cancer cells or by cells infected by a cancer-inducing virus and has a local immunosuppressive and/or angiogenic activity with respect to the cancer cells to be inhibited, by physical and/or chemical treatment, and/or by modification of the amino acid sequence thereof, so as to eliminate at least 70% of the immunosuppressive and/or angiogenic activity of the non-inactivated factor and yet to retain sufficient immunogenic properties to raise antibodies that neutralize the immunosuppressive and/or angiogenic activity of the factor;
• and
• administering said inactivated protein to the patient in a manner such that antibodies thereto are produced in a quantity sufficient to combine with the factor and to neutralize the immunosuppressive and/or angiogenic activity of the factor, thereby inhibiting the proliferation of the cells, wherein said factor is other than Tat.

An immunogenic polypeptide that is useful for inhibiting the proliferation of cancer cells in a patient, said polypeptide consisting of an inactivated form of a soluble factor which is released or induced by cancer cells or by cells infected by a cancer-inducing virus and has a local immunosuppressive and/or angiogenic activity with respect to the cancer cells to be inhibited, said inactivated polypeptide being the carboxyamidated form of said factor, or of a fragment of said factor, which fragment is large enough such that the carboxyamidated form thereof is capable of raising antibodies that neutralize the immunosuppressive and/or angiogenic activity of said factor.