Methods and compositions for the inhibition of transplant rejection

A method for inhibiting or reducing rejection of a tissue or organ transplant in a human subject,

• comprising administering to the subject two or more pharmaceutical dosage units, each dosage unit comprising
• a dose of 3 mg/kg to 25 mg/kg of a fusion protein comprising a B7-H4 polypeptide comprising the IgV domain of SEQ ID NO:63 or SEQ ID NO:64 fused to a second polypeptide or fused to a linker peptide fused to a second polypeptide comprising
• the hinge, CH2 and CH3 regions of an immunoglobulin,
• wherein at least two of the dosage units are administered at least two days apart and within two weeks,
• to increase the ratio of regulatory T cells (Tregs) relative to total CD4+ cells in the subject and reduce rejection of the tissue or organ transplant in the subject for at least a week post administration.

A method for treating one or more symptoms of graft versus host disease (GVHD) in a human subject,

• comprising administering to the subject two or more pharmaceutical dosage units, each dosage unit comprising
• a dose of 3 mg/kg to 25 mg/kg of a fusion protein comprising a B7-H4 polypeptide comprising the IgV domain of SEQ ID NO:63 or SEQ ID NO:64 fused to a second polypeptide or fused to a linker peptide fused to a second polypeptide,
• wherein at least two of the dosage units are administered at least two days apart and within two weeks,
• to increase the ratio of regulatory T cells (Tregs) relative to total CD4+ cells in the subject and reduce one or more symptoms of GVHD in the subject for at least a week post administration.

A method for treating one or more symptoms of graft versus host disease (GVHD) in a human subject,

• comprising administering to the subject two or more pharmaceutical dosage units, each dosage unit comprising
• a dose of 3 mg/kg to 25 mg/kg of a fusion protein comprising a B7-H4 polypeptide comprising the IgV domain of SEQ ID NO:63 or SEQ ID NO:64 fused to a second polypeptide or fused to a linker peptide fused to a second polypeptide,
• wherein the second polypeptide comprises the hinge, CH2 and CH3 regions of an immunoglobulin,
• wherein at least two of the dosage units are administered at least two days apart and within two weeks,
• to increase the ratio of regulatory T cells (Tregs) relative to total CD4+ cells in the subject and reduce one or more symptoms of GVHD in the subject for at least a week post administration.

A method for inhibiting or reducing rejection of a tissue or organ transplant in a human subject,

• comprising administering to the subject two or more pharmaceutical dosage units, each dosage unit comprising
• a dose of 3 mg/kg to 25 mg/kg of a fusion protein comprising the amino acid sequence of SEQ ID NO:130
• wherein at least two of the dosage units are administered at least two days apart and within two weeks,
• to increase the ratio of regulatory T cells (Tregs) relative to total CD4+ cells in the subject and reduce rejection of tissue or organ transplant in the subject for at least a week post administration.