Abstract: An antigen-loaded nanogel is formed by loading or encapsulating one or more long peptide antigens or one or more protein antigens in a hydrophobized polysaccharide. The long peptide antigen(s) or protein antigen(s) contains (or each contain) one or more CD8+ cytotoxic T cell recognition epitopes and/or one or more CD4+ helper T cell recognition epitopes, which is/are derived from the antigen. The antigen-loaded nanogel is administered at least one day prior to administration of antigen-specific T cells to improve the efficacy of a T cell infusion therapy against an immune checkpoint inhibitor-resistant tumor. The hydrophobized polysaccharide may be pullulan having cholesteryl groups bound thereto. An immune-enhancing agent also may be administered in or with the antigen-loaded nanogel.

Abstract: An object is to provide a technique of forming CpG oligonucleotides and hydrophobized polysaccharides into complexes. This object is achieved by a complex comprising a modified CpG oligonucleotide containing a hydrophobic group A having a sterol skeleton, and a modified polysaccharide containing a hydrophobic group B.

Abstract: A long-chain peptide antigen includes a plurality of epitopes. An interepitope sequence located between two of the plurality of epitopes contains four to ten consecutive tyrosines, threonines, alanines, histidines, glutamines, or asparagines. The killer T-cell recognition epitopes form complexes with MHC class I molecules and are recognized by CD8+ killer T-cells when the complexes are presented on the surfaces of antigen-presenting cells. The helper T-cell recognition epitopes form complexes with MHC class II molecules and are recognized by CD4+ helper T-cells when the complexes are presented on the surfaces of antigen-presenting cells. The peptide is cleaved within the first interepitope sequence upon uptake of the peptide into antigen-presenting cells. The long-chain peptide antigen may be administered to a patient together with a hydrophobized polysaccharide, such as cholesterol-modified pullulan, and/or an adjuvant, such as CpG oligo DNA.

Abstract: To provide an agent for overcoming immunosuppression which can overcome immunosuppression by regulatory T cells. An agent for overcoming immunosuppression and an inhibitor of FOXP3 function containing an anthracycline antibiotic as an active ingredient.

Abstract: A long-chain peptide antigen includes a plurality of epitopes. An interepitope sequence located between two of the plurality of epitopes contains four to ten consecutive tyrosines. The long-chain peptide antigen may be administered to a patient together with a hydrophobized polysaccharide, such as cholesterol-modified pullulan, and/or an adjuvant, such as CpG oligo DNA.

Abstract: Therapeutic agents effective for treating cell-proliferative diseases contain extracellular vesicles (exosomes) released from cytotoxic T cells or miRNA obtained from extracellular vesicles (exosomes) released from cytotoxic T cells, such as human CD8+ T cells. Such therapeutic agents suppress the proliferation of mesenchymal cells surrounding cancer cells, e.g., by killing the mesenchymal cells, such that the cancer cells become isolated and unable to metastasize. Cell-proliferative diseases are thus treatable by administering such a therapeutic agent to a patient.

Abstract: An antigen-loaded nanogel is formed by loading or encapsulating one or more long peptide antigens or one or more protein antigens in a hydrophobized polysaccharide. The long peptide antigen(s) or protein antigen(s) contains (or each contain) one or more CD8+ cytotoxic T cell recognition epitopes and/or one or more CD4+ helper T cell recognition epitopes, which is/are derived from the antigen. The antigen-loaded nanogel may be administered prior to administration of antigen-specific T cells to improve the efficacy of a T cell infusion therapy against an immune checkpoint inhibitor-resistant tumor. The hydrophobized polysaccharide may be pullulan having cholesteryl groups bound thereto. An immune-enhancing agent also may be administered in or with the antigen-loaded nanogel.

Abstract: To provide an agent for overcoming immunosuppression which can overcome immunosuppression by regulatory T cells. An agent for overcoming immunosuppression and an inhibitor of FOXP3 function containing an anthracycline antibiotic as an active ingredient.

Abstract: A long-chain peptide antigen includes a plurality of epitopes. An interepitope sequence located between two of the plurality of epitopes contains four to ten consecutive tyrosines. The long-chain peptide antigen may be administered to a patient together with a hydrophobized polysaccharide, such as cholesterol-modified pullulan, and/or an adjuvant, such as CpG oligo DNA.

Abstract: Therapeutic agents effective for treating cell-proliferative diseases contain extracellular vesicles (exosomes) released from cytotoxic T cells or miRNA obtained from extracellular vesicles (exosomes) released from cytotoxic T cells, such as human CD8+ T cells. Such therapeutic agents suppress the proliferation of mesenchymal cells surrounding cancer cells, e.g., by killing the mesenchymal cells, such that the cancer cells become isolated and unable to metastasize. Cell-proliferative diseases are thus treatable by administering such a therapeutic agent to a patient.

Abstract: A vaccine contains a long-chain peptide antigen having a plurality of epitopes. An interepitope sequence located between two of the plurality of epitopes contains two to ten consecutive tyrosines, two to ten consecutive threonines, two to ten consecutive alanines, two to ten consecutive histidines, two to ten consecutive glutamines or two to ten consecutive asparagines. The vaccine may be an anticancer vaccine, an antibacterial vaccine or an antiviral vaccine. The vaccine may be a peptide vaccine, a DNA vaccine, an mRNA vaccine or a dendritic cell vaccine.

Abstract: A vaccine preparation for treating cancer includes a complex of a hydrophobized polysaccharide and at least one synthetic long peptide derived from a tumor-specific antigenic protein and/or a pathogen-derived antigenic protein. The at least one synthetic long peptide contains at least one CD8+ cytotoxic T-cell recognition epitope and at least one CD4+ helper T-cell recognition epitope. The complex is simultaneously administered to the patient with at least one immunopotentiating agent.

Abstract: A process for producing an embedded protein antigen, comprising embedding a protein antigen having two or more cysteine residues in a molecule thereof, into a hydrophobized polysaccharid. Prior to or after the embedding of the protein antigen, the protein antigen is purified. There are provided an embedded protein antigen and a process for producing the same, which can advantageously purify the protein antigen, while suppressing the denaturation of the protein antigen as completely as possible.