Listeria-Vectored Multiantigenic Tuberculosis Vaccine Enhances Protective Immunity against Aerosol Challenge with Virulent Mycobacterium tuberculosis in BCG-Immunized C57BL/6 and BALB/c Mice

Abstract

TB, one of the world's most important infectious diseases, afflicts approximately 10 million people and kills approximately 1.5 million people annually. The current vaccine, BCG, developed over a century ago, has been administered to about 5 billion people, mostly in infancy, but is only modestly protective.

Listeria-vectored multi-antigenic tuberculosis vaccine protects C57BL/6 and BALB/c mice and guinea pigs against Mycobacterium tuberculosis challenge

“…Construction and verification of rLm9Ag expressing fusion proteins of Mtb5Ag and Mtb5AgII from the comK and tRNA arg loci, respectively. To construct rLm5Ag (expressing Mtb Mpt64-EsxH-EsxA-EsxB-r30, with an N-terminal fusion to ActAN, the N-terminal 100 amino acids of Lm ActA) 23 (Supplementary Table 1) and rLm5AgII (expressing ActAN-Mpt64-EsxN-PPE68-EspA-TB8.4) (Supplementary Table 1), we integrated the pPL2e-ActAN-Mtb5Ag and pPL2e-ActAN-Mtb5AgII into the tRNA arg locus of the rLm chromosome (Fig. 1a, top and middle vaccines).…”

“…Prime vaccines under development, all comprising mycobacteria, include rBCG30, the first vaccine demonstrated more potent than BCG and the first potential replacement vaccine for BCG to enter human trials [4][5][6][7] ; rBCG(mbtB)30, the first vaccine demonstrated more potent and safer than BCG 8 ; MTBVAC, an attenuated Mtb 9 , and VPM-1002, a modified BCG 10 . TB booster vaccines under development, all subunit vaccines, include protein/adjuvant vaccines such as r30 (Antigen 85B), the first defined booster vaccine against TB 4 , H1 (Antigen 85B -ESAT6) 11,12 , H4 (Antigen 85B-TB10.4) 13,14 , M72 15,16 , and ID93 17,18 ; virus vectored vaccines such as MVA85A 19,20 ; and bacterium vectored vaccines including Salmonella-vectored vaccines 21 and Listeria-vectored vaccines, including rLm30 22 and rLmMtb5Ag 23 , as well as rLmMtb9Ag, described herein.…”

“…Using Lm ΔactA ΔinlB prfA* as a vaccine vector, we have developed several recombinant Lm-vectored Mtb vaccines (rLm) including rLm30 22 , rLmMtb5Ag (rLm5Ag) 23 , and in this study, rLmMtb9Ag (rLm9Ag). The rLm30 vaccine expresses a single Mtb antigenthe 30-kDa major secretory protein or Antigen 85B (r30 or Ag85B, gene Rv1886); rLm5Ag expresses a fusion protein of 5 Mtb antigens − Mpt64/23.5 (Rv1980c), EsxH/TB10.4 (Rv0288), EsxA/ESAT6 (Rv3875), EsxB/CFP10 (Rv3874) and r30; and rLm9Ag expresses, in addition to the 5 antigens expressed by rLm5Ag, a fusion protein comprising 4 additional Mtb antigens -EspA (Rv3616c), EsxN (Rv1793), PPE68 (Rv3873) and TB8.4 (Rv1174c).…”

“…The rLm30 vaccine expresses a single Mtb antigenthe 30-kDa major secretory protein or Antigen 85B (r30 or Ag85B, gene Rv1886); rLm5Ag expresses a fusion protein of 5 Mtb antigens − Mpt64/23.5 (Rv1980c), EsxH/TB10.4 (Rv0288), EsxA/ESAT6 (Rv3875), EsxB/CFP10 (Rv3874) and r30; and rLm9Ag expresses, in addition to the 5 antigens expressed by rLm5Ag, a fusion protein comprising 4 additional Mtb antigens -EspA (Rv3616c), EsxN (Rv1793), PPE68 (Rv3873) and TB8.4 (Rv1174c). These 4 additional proteins were selected on the basis of their capacity, when administered as part of a rLm booster vaccine, to enhance protective immunity against Mtb aerosol challenge in BCG-immunized mice 23 . In previous studies of rLm30 and rLm5Ag, we have shown that i) immunization of mice with BCG has no significant effect on local replication or systemic dissemination, growth, and clearance of rLm30 administered intradermally 12 or 15 weeks later 22,23 ; ii) boosting BCG-primed mice with rLm30 and rLm5Ag enhances Mtb antigen-specific CD4+ and CD8+ T cell-mediated immune responses 22,23 ; and iii) boosting BCG-primed C57BL/6 and BALB/c mice with rLm30 and rLm5Ag enhances protective immunity against aerosolized Mtb 22,23 .…”

“…These 4 additional proteins were selected on the basis of their capacity, when administered as part of a rLm booster vaccine, to enhance protective immunity against Mtb aerosol challenge in BCG-immunized mice 23 . In previous studies of rLm30 and rLm5Ag, we have shown that i) immunization of mice with BCG has no significant effect on local replication or systemic dissemination, growth, and clearance of rLm30 administered intradermally 12 or 15 weeks later 22,23 ; ii) boosting BCG-primed mice with rLm30 and rLm5Ag enhances Mtb antigen-specific CD4+ and CD8+ T cell-mediated immune responses 22,23 ; and iii) boosting BCG-primed C57BL/6 and BALB/c mice with rLm30 and rLm5Ag enhances protective immunity against aerosolized Mtb 22,23 .…”