Stabilized HBc chimer particles as therapeutic vaccine for chronic hepatitis

A method of treating chronic hepatitis comprising

• administering to a patient in need thereof a T cell-stimulating amount of vaccine comprised of an immunogenic effective amount of immunogenic particles dissolved or dispersed in a pharmaceutically acceptable diluent, said immunogenic particles being comprised of recombinant hepatitis B virus core (HBc) protein chimer molecules that have a length of about 135 to about 525 amino acid residues and contain four peptide-linked amino acid residue sequence domains from the N-terminus that are denominated Domains I, II, III and IV, wherein
• (i) Domain I comprises about 71 to about 110 amino acid residues whose sequence includes (a′) at least the sequence of the residues of position 5 through position 75 of HBc, (b′) zero to three cysteine residues at an amino acid position of the chimer molecule corresponding to amino acid position −20 to about +1 from the N-terminus of the HBc sequence of SEQ ID NO:1 [N-terminal cysteine residue(s)] in a sequence other than that of the HBc precore sequence, and (c′) an optional immunogenic epitope containing up to about 30 amino acid residues peptide-bonded to one of HBc residues 2-4;
• (ii) Domain II comprises about 5 to about 250 amino acid residues peptide-bonded to HBc residue 75 of Domain I in which (a′) zero to all residues in the sequence of HBc positions 76 through 85 are present peptide-bonded to (b′) an optionally present sequence of one to about 245 amino acid residues that constitute an immunogenic epitope or a heterologous linker residue for a conjugated epitope;
• (ii) Domain III is an HBc sequence from position 86 through position 135 peptide-bonded to residue 85 of Domain II;
• and
• (iv) Domain IV comprises (a′) five through fourteen residues of an HBc amino acid residue sequence from position 136 through 149 peptide-bonded to the residue of position 135 of Domain III, (b′) zero to three cysteine residues [C-terminal cysteine residue(s)] within about 30 residues from the C-terminus of the chimer molecule, and (c′) zero to about 100 amino acid residues in an immunogenic sequence heterologous to HBc from position 165 to the C-terminus,
• said chimer molecule (i) having an amino acid residue sequence in which no more than about 10 percent of the amino acid residues are substituted in the HBc sequence of the chimer, (ii) self-assembling into particles on expression in a host cell and (iii) containing at least one N-terminal cysteine residue or C-terminal cysteine residue, said particles being substantially free of binding to nucleic acids and being more stable than are particles formed from otherwise identical HBc chimer molecules that are (i) free of any above-mentioned C-terminal cysteine residue(s) or N-terminal cysteine residue(s) or (ii) in which said cysteine residue(s) of (iii) present in a contemplated chimer molecule is(are) replaced by another residue.

A method of treating chronic hepatitis comprising

• administering to a patient in need thereof a T cell-stimulating amount of a vaccine comprised of an immunogenic effective amount of immunogenic particles dissolved or dispersed in a pharmaceutically acceptable diluent, said immunogenic particles being comprised of recombinant hepatitis B virus core (HBc) protein chimer molecules with a length of about 170 to about 250 amino acid residues that contains four peptide-linked amino acid residue sequence domains from the N-terminus that are denominated Domains I, II, III and IV, wherein
• (a) Domain I comprises about the sequence of the residues of position 4 through position 75 of HBc as well as a first sequence of up to about 25 residues in a first sequence peptide-bonded to the amino-terminal HBC residue of said sequence, said sequence of up to about 25 residues containing zero or one cysteine residue at an amino acid position of the chimer molecule corresponding to amino acid position −14 to about +1 from the N-terminus of the HBc sequence of SEQ ID NO:1 [N-terminal cysteine residue];
• (b) Domain II comprises about 5 to about 55 amino acid residues peptide-bonded to HBc residue 75 of Domain I in which at least 4 residues in a sequence of HBc positions 76 through 85 are present peptide-bonded to an optional second sequence heterologous to HBc at positions 76 through 85 of up to about 50 amino acid residues;
• (c) Domain III is an HBc sequence from position 86 through position 135 peptide-bonded to residue 85 of Domain II;
• and
• d) Domain IV comprises (i) 5 through fourteen residues of a HBc amino acid residue sequence from position 136 through 149 peptide-bonded to the residue of position 135 of Domain III, (ii) zero or one cysteine residue [C-terminal cysteine residue] within about 30 residues of the C-terminus of the chimer molecule, and (iii) zero to about 50 amino acid residues in a third sequence heterologous to HBc from position 165 to the C-terminus,
• said chimer molecules (i) self-assembling into particles on expression in a host cell, (ii) including at least one or the other of said N-terminal cysteine residue or C-terminal cysteine residue and (iii) having an amino acid residue sequence in which no more than about 5 percent of the amino acid residues are substituted in the HBc sequence of the chimer relative to the sequence shown in the HBc sequence of SEQ ID NO:1, said particles exhibiting a ratio of absorbance at 280 nm to 260 nm of about 1.2 to about 1.7 and being more stable than are particles formed from otherwise identical HBc chimer molecules that lack said N-terminal cysteine residue or C-terminal cysteine residue that is present or in which the N-terminal cysteine or C-terminal cysteine residue present in the chimer molecule is replaced by another residue.