Delineating Surface Epitopes of Lyme Disease Pathogen Targeted by Highly Protective Antibodies of New Zealand White Rabbits

Abstract

Lyme disease (LD), the most prevalent vector-borne illness in the United States and Europe, is caused by Borreliella burgdorferi. No vaccine is available for humans. Dogmatically, B. burgdorferi can establish a persistent infection in the mammalian host (e.g., mice) due to a surface antigen, VlsE. This antigenically variable protein allows the spirochete to continually evade borreliacidal antibodies. However, our recent study has shown that the B. burgdorferi spirochete is effectively cleared by anti-B. burgdorferi antibodies of New Zealand White rabbits, despite the surface expression of VlsE. Besides homologous protection, the rabbit antibodies also crossprotect against heterologous B. burgdorferi spirochetes and significantly reduce the pathology of LD arthritis in persistently infected mice. Thus, this finding that NZW rabbits develop a unique repertoire of very potent antibodies targeting the protective surface epitopes, despite abundant VlsE, prompted us to identify the specificities of the protective rabbit antibodies and their respective targets. By applying subtractive reverse vaccinology, which involved the use of random peptide phage display libraries coupled with next-generation sequencing and our computational algorithms, repertoires of nonprotective (early) and protective (late) rabbit antibodies were identified and directly compared. Consequently, putative surface epitopes that are unique to the protective rabbit sera were mapped. Importantly, the relevance of newly identified protection-associated epitopes for their surface exposure has been strongly supported by prior empirical studies. This study is significant because it now allows us to systematically test the putative epitopes for their protective efficacy with an ultimate goal of selecting the most efficacious targets for development of a long-awaited LD vaccine.

Comparison of motif-based and whole-unique-sequence-based analyses of phage display library datasets generated by biopanning of anti-Borrelia burgdorferi immune sera

“…Our follow-up study defined specificities of day-14 (non-protective) and day-28 (protective) rabbit antibodies via the PDRPL/NGS and then directly compared the two repertoires. As a result, specificities of the rabbit protective antibodies and their respective targets were identified [9].…”

“…In the present study, we have compared two distinct approaches, the WUSA and MA, for the analysis of the PDRPL/NGS data [9]. Both approaches directly compared mimotope sequences between the day-14 (non-protective) and day-28 (protective) immune serum samples from 3 NZW rabbits (animals P, Y, and Z).…”

“…The preimmune sera were pooled from the 3 rabbits prior to their challenge with wild-type B. burgdorferi B31-A3 strain and served as a background control. To obtain mimotope sequences, 1 pooled preimmune, 3 non-protective, and 3 protective serum samples (referred to here as PI, NP, and PR samples, respectively) were analyzed via commercially available Ph.D.-7 library of random heptapeptides followed by sequencing via Illumina 2500 sequencing platform [9]. One PR sample was analyzed in duplicate (samples P28a and P28b).…”

“…Identification of protection-associated (PA) antigens and/or their epitopes via reverse vaccinology is one of the very first steps for development of vaccines against human pathogens [1][2][3][4][5][6][7][8][9]. To select the most promising vaccine candidate(s) initially requires mapping multiple PA targets, which then can be individually tested for their protective efficacy via animal immunization assays [10].…”

The power of phages: revolutionizing cancer treatment

“…It has been widely utilized in the development of vaccines against various microorganisms, including cancer causing pathogens ( 112 ). Researchers have employed phage display libraries to identify immunodominant and immunogenic B-cell epitopes that neutralize toxins from pathogens such as Staphylococcus aureus ( 117 ), Escherichia coli ( 112 ), Salmonella typhi ( 118 ), Borrelia burgdorferi ( 119 ), and viruses like SARS-CoV-2 ( 120 ), Ebola Virus ( 121 ), and Zika virus ( 122 ). Engineered filamentous phages have been employed as direct immunogens in various scenarios, such as immunization against Plasmodium falciparum , the parasite responsible for malaria.…”