Testing the\nAntigenic Potential of Transmembrane Proteins\nTo Develop a Thermostable Tuberculosis MOF-Liposomal Vaccine

Tuberculosis is one of the deadliest infectious diseases\nand continues\nto be a major health risk in many parts of the world. Even today,\nthe century-old Bacillus Calmette-Guerin (BCG) vaccine is the only\nformulation on the market and is ineffective for several sections\nof the global population responsible for transmission. In the search\nfor antigens that can mount a robust immune response, we have reported\nthe recombinant expression and purification of two novel membrane\nproteins, the Cation transporter protein V (CtpV) and the Mycobacterial\ncopper transporter B (MctB) present on the membrane surface of Mycobacterium tuberculosis. CtpV was tested as an\nantigen against the plasma of tuberculosis patients and was found\nto have a unique immune response profile compared with more commonly\nstudied tuberculosis (TB) antigens. CtpV and MctB were reconstituted\ninto proteoliposomesindividually and in combinationto\nstabilize them in a lipid bilayer and create a nanoparticle vaccine\nplatform. <i>In vivo</i> experiments demonstrated that when\ndelivered with an adjuvant, these antigens generated a robust Th1-biased\nT-cell response in mice, with the combination of both antigens performing\nthe best and generating a response comparable to BCG. Since tuberculosis\nvaccines often need to be shipped to areas with fluctuating power\nsupply, we encapsulated the proteoliposomes and the adjuvant in ZIF-8\nto create a shelf-stable formulation. Complementary <i>in vivo</i> studies were carried out to confirm that the ZIF-8 coating did not\ninterfere with or compromise the immunogenicity of the antigens.