Polysaccharides (PS) represent major protective antigens on the surface of many pathogenic bacteria cells and have therefore been targets of successful and effective vaccines to prevent infectious disease. Conjugation of PS to proteins is currently the most established way to make immunogenic PS vaccines. However, conjugation technology is expensive and technically challenging. The Mekalanos laboratory has developed a simple and inexpensive way of making 'virtual conjugate vaccines'that employs Protein Capsular Matrix Vaccine (PCMV) technology. This proposal seeks to extend PCMV technology to modify killed whole cell bacteria vaccines (wcPCMV) and thus render them immunogenic after oral immunization and capable of inducing 'conjugate-like'immune responses against surface PS of bacterial cells. This will be accomplished by using a bifunctional molecular cross-linker (glutaraldehyde) to drive extensive proteinprotein coupling in the vicinity of surface-localized PS chains, thus entrapping the PS in a protein mesh that will remain associated with them after dissolution of the cell by elements of the host immune system. Thus, B cells expressing antibody receptors that recognize PS will take up PS only in the context of PCMV carrier protein. This process should (as with conjugate vaccines) trigger activation of T helper cells that instruct B cells to undergo replication, immunoglobulin class switching, and mutational affinity maturation of their anti- PS antibody genes. We will make wcPCMV vaccines for several species of organisms to control for the effect ofthe chemistry of different PS surface structures, and their density on the cell surface. These will include the O1 Inaba, O1 Ogawa and 0139 serogroups of Vibrio cholerae and Vi encapsulated Salmonella typhi. As a control for the properties of wcPCMV versus conventional PCMV and conjugates, we will also evaluate the method on several encapsulated types of Streptococcus pneumoniae, a Gram-positive bacterium. The wcPCMV vaccines will be explored as immunogens using both parenteral and mucosal routes of administration. The functionality of wcPCMV-induced antibodies will be assessed for complement dependent bacteriolysis activity, as well as their ability to protect experimental animals from direct pathogenic bacterial challenge. This proposal may lead to a multivalent wcPCMV vaccine against cholera, . brucellosis, 0157 E. coli, and anthrax. However, wcPCMV technology could more broadly impact mucosal vaccine development for many other mucosal bacterial pathogens that display PS on their surface.

Public Health Relevance

Immunization with polysaccharide-protein conjugate vaccines is an effective way to induce protective immune responses against many bacterial pathogens. Combination vaccines directed against multiple pathogens are highly desirable. However, conjugation technology is expensive and technically challenging. This proposal seeks to extend the use of a new alternate technology. Protein Capsular Matrix Vaccine technology, to whole cell bacteria vaccines to generate conjugate-like immune responses. If successful, this technology will simplify the preparation of vaccines directed against bacterial pathogens and further enable the development of vaccines directed against multiple pathogens

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Program--Cooperative Agreements (U19)
Project #
Application #
Study Section
Special Emphasis Panel (ZAI1-LR-M (J1))
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Harvard University
United States
Zip Code
Lorenz, Christian; Dougherty, Thomas J; Lory, Stephen (2016) Transcriptional Responses of Escherichia coli to a Small-Molecule Inhibitor of LolCDE, an Essential Component of the Lipoprotein Transport Pathway. J Bacteriol 198:3162-3175
Markovski, Monica; Bohrhunter, Jessica L; Lupoli, Tania J et al. (2016) Cofactor bypass variants reveal a conformational control mechanism governing cell wall polymerase activity. Proc Natl Acad Sci U S A 113:4788-93
Rajagopal, Mithila; Martin, Melissa J; Santiago, Marina et al. (2016) Multidrug Intrinsic Resistance Factors in Staphylococcus aureus Identified by Profiling Fitness within High-Diversity Transposon Libraries. MBio 7:
Simpson, Brent W; Owens, Tristan W; Orabella, Matthew J et al. (2016) Identification of Residues in the Lipopolysaccharide ABC Transporter That Coordinate ATPase Activity with Extractor Function. MBio 7:
Matano, Leigh M; Morris, Heidi G; Wood, B McKay et al. (2016) Accelerating the discovery of antibacterial compounds using pathway-directed whole cell screening. Bioorg Med Chem 24:6307-6314
Meeske, Alexander J; Riley, Eammon P; Robins, William P et al. (2016) SEDS proteins are a widespread family of bacterial cell wall polymerases. Nature 537:634-638
Pasquina, Lincoln; Santa Maria Jr, John P; McKay Wood, B et al. (2016) A synthetic lethal approach for compound and target identification in Staphylococcus aureus. Nat Chem Biol 12:40-5
Lee, Wonsik; Schaefer, Kaitlin; Qiao, Yuan et al. (2016) The Mechanism of Action of Lysobactin. J Am Chem Soc 138:100-3
Cho, Hongbaek; Wivagg, Carl N; Kapoor, Mrinal et al. (2016) Bacterial cell wall biogenesis is mediated by SEDS and PBP polymerase families functioning semi-autonomously. Nat Microbiol :16172
Meeske, Alexander J; Rodrigues, Christopher D A; Brady, Jacqueline et al. (2016) High-Throughput Genetic Screens Identify a Large and Diverse Collection of New Sporulation Genes in Bacillus subtilis. PLoS Biol 14:e1002341

Showing the most recent 10 out of 17 publications