1
|
Foor SD, Brangulis K, Shakya AK, Rana VS, Bista S, Kitsou C, Ronzetti M, Alreja AB, Linden SB, Altieri AS, Baljinnyam B, Akopjana I, Nelson DC, Simeonov A, Herzberg O, Caimano MJ, Pal U. A unique borrelial protein facilitates microbial immune evasion. mBio 2023; 14:e0213523. [PMID: 37830812 PMCID: PMC10653885 DOI: 10.1128/mbio.02135-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 10/14/2023] Open
Abstract
IMPORTANCE Lyme disease is a major tick-borne infection caused by a bacterial pathogen called Borrelia burgdorferi, which is transmitted by ticks and affects hundreds of thousands of people every year. These bacterial pathogens are distinct from other genera of microbes because of their distinct features and ability to transmit a multi-system infection to a range of vertebrates, including humans. Progress in understanding the infection biology of Lyme disease, and thus advancements towards its prevention, are hindered by an incomplete understanding of the microbiology of B. burgdorferi, partly due to the occurrence of many unique borrelial proteins that are structurally unrelated to proteins of known functions yet are indispensable for pathogen survival. We herein report the use of diverse technologies to examine the structure and function of a unique B. burgdorferi protein, annotated as BB0238-an essential virulence determinant. We show that the protein is structurally organized into two distinct domains, is involved in multiplex protein-protein interactions, and facilitates tick-to-mouse pathogen transmission by aiding microbial evasion of early host cellular immunity. We believe that our findings will further enrich our understanding of the microbiology of B. burgdorferi, potentially impacting the future development of novel prevention strategies against a widespread tick-transmitted infection.
Collapse
Affiliation(s)
- Shelby D. Foor
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Kalvis Brangulis
- Latvian Biomedical Research and Study Centre, Riga, Latvia
- Department of Human Physiology and Biochemistry, Riga Stradins University, Riga, Latvia
| | - Anil K. Shakya
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Vipin S. Rana
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Sandhya Bista
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Chrysoula Kitsou
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Michael Ronzetti
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Adit B. Alreja
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Sara B. Linden
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Amanda S. Altieri
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Bolormaa Baljinnyam
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Inara Akopjana
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Daniel C. Nelson
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Osnat Herzberg
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, USA
| | - Melissa J. Caimano
- Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Utpal Pal
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
- Virginia-Maryland College of Veterinary Medicine, College Park, Maryland, USA
| |
Collapse
|
2
|
Thakur M, Bista S, Foor SD, Dutta S, Yang X, Ronzetti M, Rana VS, Kitsou C, Linden SB, Altieri AS, Baljinnyam B, Nelson DC, Simeonov A, Pal U. Controlled Proteolysis of an Essential Virulence Determinant Dictates Infectivity of Lyme Disease Pathogens. Infect Immun 2022;:e0005922. [PMID: 35416705 DOI: 10.1128/iai.00059-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The Borrelia burgdorferi BB0323 protein undergoes a complex yet poorly defined proteolytic maturation event that generates N-terminal and C-terminal proteins with essential functions in cell growth and infection. Here, we report that a borrelial protease, B. burgdorferi high temperature requirement A protease (BbHtrA), cleaves BB0323 between asparagine (N) and leucine (L) at positions 236 and 237, while the replacement of these residues with alanine in the mutant protein prevents its cleavage, despite preserving its normal secondary structure. The N-terminal BB0323 protein binds BbHtrA, but its cleavage site mutant displays deficiency in such interaction. An isogenic borrelial mutant with NL-to-AA substitution in BB0323 (referred to as Bbbb0323NL) maintains normal growth yet is impaired for infection of mice or transmission from infected ticks. Notably, the BB0323 protein is still processed in Bbbb0323NL, albeit with lower levels of mature N-terminal BB0323 protein and multiple aberrantly processed polypeptides, which could result from nonspecific cleavages at other asparagine and leucine residues in the protein. The lack of infectivity of Bbbb0323NL is likely due to the impaired abundance or stoichiometry of a protein complex involving BB0238, another spirochete protein. Together, these studies highlight that a precise proteolytic event and a particular protein-protein interaction, involving multiple borrelial virulence determinants, are mutually inclusive and interconnected, playing essential roles in the infectivity of Lyme disease pathogens.
Collapse
|
3
|
Cole GB, Bateman TJ, Moraes TF. The surface lipoproteins of gram-negative bacteria: Protectors and foragers in harsh environments. J Biol Chem 2021; 296:100147. [PMID: 33277359 PMCID: PMC7857515 DOI: 10.1074/jbc.rev120.008745] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 11/06/2022] Open
Abstract
Gram-negative pathogens are enveloped by an outer membrane that serves as a double-edged sword: On the one hand, it provides a layer of protection for the bacterium from environmental insults, including other bacteria and the host immune system. On the other hand, it restricts movement of vital nutrients into the cell and provides a plethora of antigens that can be detected by host immune systems. One strategy used to overcome these limitations is the decoration of the outer surface of gram-negative bacteria with proteins tethered to the outer membrane through a lipid anchor. These surface lipoproteins (SLPs) fulfill critical roles in immune evasion and nutrient acquisition, but as more bacterial genomes are sequenced, we are beginning to discover their prevalence and their different roles and mechanisms and importantly how we can exploit them as antimicrobial targets. This review will focus on representative SLPs that gram-negative bacteria use to overcome host innate immunity, specifically the areas of nutritional immunity and complement system evasion. We elaborate on the structures of some notable SLPs required for binding target molecules in hosts and how this information can be used alongside bioinformatics to understand mechanisms of binding and in the discovery of new SLPs. This information provides a foundation for the development of therapeutics and the design of vaccine antigens.
Collapse
Affiliation(s)
- Gregory B Cole
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Thomas J Bateman
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Trevor F Moraes
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
4
|
Abstract
Borrelia burgdorferi sensu lato causes Lyme borreliosis in a variety of animals and humans. These atypical bacterial pathogens are maintained in a complex enzootic life cycle that primarily involves a vertebrate host and Ixodes spp. ticks. In the Northeastern United States, I. scapularis is the main vector, while wild rodents serve as the mammalian reservoir host. As B. burgdorferi is transmitted only by I. scapularis and closely related ticks, the spirochete-tick interactions are thought to be highly specific. Various borrelial and arthropod proteins that directly or indirectly contribute to the natural cycle of B. burgdorferi infection have been identified. Discrete molecular interactions between spirochetes and tick components also have been discovered, which often play critical roles in pathogen persistence and transmission by the arthropod vector. This review will focus on the past discoveries and future challenges that are relevant to our understanding of the molecular interactions between B. burgdorferi and Ixodes ticks. This information will not only impact scientific advancements in the research of tick- transmitted infections but will also contribute to the development of novel preventive measures that interfere with the B. burgdorferi life cycle.
Collapse
Affiliation(s)
- Utpal Pal
- Department of Veterinary Medicine, University of Maryland, 8075 Greenmead Drive, College Park, MD 20742, USA
| | - Chrysoula Kitsou
- Department of Veterinary Medicine, University of Maryland, 8075 Greenmead Drive, College Park, MD 20742, USA
| | - Dan Drecktrah
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Özlem Büyüktanir Yaş
- Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Istinye University, Zeytinburnu, İstanbul, 34010, Turkey
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| |
Collapse
|