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The present invention relates to compositions containing a complex of an inactivated pepsin fraction (IPF) component and heat shock protein (HSP) peptide component (IPF-HSP complex) and methods for producing specific immunity to tumor peptides.


There are a variety of technology that modulate immune system of treat a various conditions.  For example, commonly owned US utility application #20100143291 Zhabilov discloses method for isolating and preparing an inactivated pepsin fraction (IPF) useful for detecting and treating infectious and autoimmune diseases and viral infections.

Current data indicates that immune protection against cancer requires generation of potent cellular immune responses against a unique tumor antigen expressed by malignant cells.

As a consequence successful immune protection requires:
– A unique antigen in the tumor cells (tu specific antigen)
– Induction of potent T-cell immune response.

However tumor associated antigens are recognized by immune cells as a molecule and so im. Sg. Is not activated.  Unresponsiveness of the im. Sy. To self-molecules, which restricts its ability to generate potent immune responses.  Targeting potent cellular immune response specifically tu cells to normal cells.

The cellular heat shock protein gp96- it has long been known for its ability to induce tumor-specific immunity in animals that are intrapertioneally injected with it.  HSPs isolated form tumors has been shown to elicit specific protective immunity against the tumor, used as the source of HSP.  The structural basis of this broad phenomenon lies in the fact that HSP preparations isolated from a given cell are associated with the range of peptides, including self, and antigenic peptides, generated within that cell, and that HSP peptide complexes are highly immunogenic.  In studies demonstrating the specific immunogenicity of the cognate tumor derived HSP-gp96 as such CD91.  Protein sequencing identified the molecule as CD91 which is known as the – alpha2 macroglobuline (2m) receptor expressed on phagocytes.  The presentation of a gp-96- isolated peptide by antigen presenting cells (JPC) is indeed blocked by –alpha 2 macroglobulines.  In addition to the identification of a receptor of a receptor for gp96.  Binder ct al incorporated his observation into an intriguing model for the general role of HSP in the regulation of APC function.  In tissues, CD91 becomes accessible to gp96 molecule, possibly released from necrotic cells (for example tumor) and the associated peptides can than be presented in a immunogenic context to the adaptive immune system by macrophages and thus the gp96- CD91 interactions may act as a sensor for tissue damage, furthermore the identification to apoptotic versus necrotic cell death.  Necrotic cell death includes inflammatory cytokines and the expression of costimulatory molecules on APCs.  Gp96 also delivers maturation signals to the DC, and includes the expression of MHC molecule. The ability of gp96 to transfer antigen peptides/MHC to initiate T-cell mediated anti-tumor responses and uptake and processing of tumor antigens by DC, makes it an ideal candidate for triggering an immune response in an organism in response to tumor.

It could be assumed that gp96 is binding to IPF identified as a major epitope recognized by the immune response using a non conventional antigen processing pathway.  IPF is a sterile bilogival product.  It is isolated pepsine enzyme by buffer extraction and engime cleavage.  The following have been demonstrated in several experimental studies:

  1. Increased CD8 and, iFN gamma
  2. Increased CD8 number over time
  3. Improved cellular response of both CD4 and CD8 when activated in vitro by nonspecific mitogens.



Immunotherapy has the potential to provide an alternative treatment for the most types of cancer. The advantage of immunotherapy over radiation and chemotherapy is that can act specifically against tumor without causing normal tissue damage.

Current data indicates that immune protection against all cancers requires generation of a potent immune responses against a unique tumor antigen expressed by the malignant cell.  As a consequence successful immune protection first requires a unique antigen expressed in the tumor cell (tumor-specific antigen) and second, induction of a potent T-cell immune response targeted to the tumor antigen.   Unfortunatly the immune system cannot recognize specific tumor antigens and rejects the tumor.  Resent advances of our understanding have revealed that any proteins binding with specific tumor antigens can be recognized by the immune system.  Attached proteins by tumor antigens form complex antigen.  Which will increase antibodies against them and second induction of a potent T-cell immune response targeted to the tumor antigen.  For amplification of immune response will be using a different kind of cytokines.  Complex of inactivated pepsin fraction (IPF) component and a gp96 (HSP) peptide is a method of modulating immune system activity by induce specific T-cells (CTL) responses against tumor cells.