Size tunable microbial mimetics for immunotherapy of thyroid carcinomas and solid tumors

Abstract

This invention describes novel immunogenic complexes, which are designed to trigger a robust host immune response against cancer cells by co-opting the immune system's natural ability to eliminate pathogen-infected host cells. The immunogenic complexes, referred to as microbial mimetics (MM) have unique physical and biochemical properties, which are designed to simulate a pathogenic infection of similar sized bacteria and viruses, permitting tumor-associated and tumor-specific peptide antigens to be presented to immune cells as microbial constituents. The MM are well-suited to mimic a systemic infection with microbe sized particles comprised largely of tumor antigens. Under this framework, tumor cells may be eliminated in the ensuing immune response. The microbial mimetics exhibit unique properties, including size tunability and contain antigenic cargo complexed to immune stimulatory molecules, which synergize to potentiate immune responses. The MM constitute a versatile platform for triggering immune responses against cells expressing epitopes contained within the complexed antigenic cargo.

1 . A method for treating thyroid cancer by administering to a patient with thyroid cancer the immunogenic composition comprised of RNA248 (SEQ. ID NO. 61) and one or more of the antigenic Modified Core Sequence Peptides (SEQ. ID NOS. 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 18, 19, 20, 22, 23, 24, 26, 27, 28, 30, 31, 32, 34, 35, 36, 38, 39, 40, 42, 43, 44, 46, 47, 48, 50, 51, 52, 54, 55, 56, 58, 59, 60), in any combination. 
     
     
         2 . The method of  claim 1 , wherein conservative variations of the Modified Core Sequence Peptides, such as one, two, or three amino acid modifications, may be used. 
     
     
         3 . The method of  claim 1 , wherein conservative variations of RNA248, such as one, two, or three nucleic acid modifications, may be used. 
     
     
         4 . The method of  claim 1 , wherein the subject may have medullary thyroid cancer. 
     
     
         5 . The method of  claim 1 , wherein the subject may have differentiated thyroid cancer. 
     
     
         6 . The method of  claim 1 , wherein additional immunostimulatory molecules such as gardiquimod, resiquimod, Poly(I:C), Poly-ICLC, STING agonists and/or CpG DNA may be included in the immunogenic composition. 
     
     
         7 . The method of  claim 1 , wherein the Modified Core Sequence Peptides may have the lipopeptide Pam(2)CSK4 conjugated at the amino termini. 
     
     
         8 . The method of  claim 1 , wherein the Modified Core Sequence Peptides may have the lipopeptide Pam(3)CSK4 conjugated at the amino termini. 
     
     
         9 . The method of  claim 1 , wherein the immunogenic composition may include DNA4 (SEQ. ID NO. 62). 
     
     
         10 . The method of  claim 1 , wherein the immunogenic composition may include DNA10 (SEQ. ID NO. 63). 
     
     
         11 . The method of  claim 1 , wherein the particles comprising the immunogenic composition may be tuned across several orders of magnitude and specifically to dimensions similar in size to bacteria and viruses by titrating the concentrations of each component and varying the final concentration of each component in a suitable buffer. 
     
     
         12 . The method of  claim 1 , wherein immunogenic compositions with distinct Modified Core Sequence Peptides may be separately synthesized and then mixed in a suitable buffer, forming a solution with multiple Modified Core Sequence Peptides. 
     
     
         13 . The method of  claim 1 , wherein the immunogenic composition may be co-administered with other cancer therapies, including kinase inhibitors or immune checkpoint inhibitors such as those targeting various immune checkpoints such as PD-1, PD-L1, LAG-3, TIM-3, CD27, or CD137. 
     
     
         14 . The method of  claim 1 , wherein the immunogenic composition may be used to activate and expand tumor-specific or tumor-associated T cells in vitro. 
     
     
         15 . The method of  claim 1 , wherein the immunogenic composition may be admixed with autologous heat-killed or freeze-thaw killed tumor cells and administered to a human patient for the treatment of cancer. 
     
     
         16 . The method of  claim 1 , wherein the immunogenic composition may be synthesized with a high tumor-antigen content, whereby of the total peptide mass, the mass of tumor-specific or tumor-associated polypeptides exceeds 30%. 
     
     
         17 . The method of  claim 1 , wherein the immunogenic composition may be injected directly into a subject's tumor using a syringe and needle. 
     
     
         18 . The antigenic polypeptide sequences known as the Modified Core Sequence Peptides (SEQ. ID NOS. 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 18, 19, 20, 22, 23, 24, 26, 27, 28, 30, 31, 32, 34, 35, 36, 38, 39, 40, 42, 43, 44, 46, 47, 48, 50, 51, 52, 54, 55, 56, 58, 59, 60). 
     
     
         19 . The immunogenic complexes formed by mixing in a suitable buffer RNA248 (SEQ. ID NO. 61) and DNA4 (SEQ. ID NO. 62) with any one or more polypeptide sequences of 15 to 35 amino acids that also have the RRHRKRR (SEQ. ID NO. 64) linker sequence and Pam(2)CSK4 or Pam(3)CSK4 lipopeptides at the amino terminus.