Abstract
Arthropod-borne pathogens are responsible for hundreds of millions of infections in humans each year. The blacklegged tick, Ixodes scapularis, is the predominant arthropod vector in the United States and is responsible for transmitting several human pathogens, including the Lyme disease spirochete Borrelia burgdorferi and the obligate intracellular rickettsial bacterium Anaplasma phagocytophilum, which causes human granulocytic anaplasmosis. However, tick metabolic response to microbes and whether metabolite allocation occurs upon infection remain unknown. Here we investigated metabolic reprogramming in the tick ectoparasite I. scapularis and determined that the rickettsial bacterium A. phagocytophilum and the spirochete B. burgdorferi induced glycolysis in tick cells. Surprisingly, the endosymbiont Rickettsia buchneri had a minimal effect on bioenergetics. An unbiased metabolomics approach following A. phagocytophilum infection of tick cells showed alterations in carbohydrate, lipid, nucleotide and protein metabolism, including elevated levels of the pleiotropic metabolite β-aminoisobutyric acid. We manipulated the expression of genes associated with β-aminoisobutyric acid metabolism in I. scapularis, resulting in feeding impairment, diminished survival and reduced bacterial acquisition post haematophagy. Collectively, we discovered that metabolic reprogramming affects interspecies relationships and fitness in the clinically relevant tick I. scapularis.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
Metabolomics data are available at MetaboLights (identifier MTBLS686), a database from the European Bioinformatics Institute. Synthetic nucleotide information and reagents/resources are included in Supplementary Tables 1 and 2, respectively. Source data are provided with this paper.
References
Vector-borne Diseases (WHO, 2020); https://www.who.int/news-room/fact-sheets/detail/vector-borne-diseases
Kurokawa, C. et al. Interactions between Borrelia burgdorferi and ticks. Nat. Rev. Microbiol. 18, 587–600 (2020).
Lochhead, R. B., Strle, K., Arvikar, S. L., Weis, J. J. & Steere, A. C. Lyme arthritis: linking infection, inflammation and autoimmunity. Nat. Rev. Rheumatol. 17, 449–461 (2021).
O’Neal, A. J., Singh, N., Mendes, M. T. & Pedra, J. H. F. The genus Anaplasma: drawing back the curtain on tick–pathogen interactions. Pathog. Dis. 79, ftab022 (2021).
Smith, R. P. Tick-borne diseases of humans. Emerg. Infect. Dis. 11, 1808–1809 (2005).
Verhoeve, V. I., Fauntleroy, T. D., Risteen, R. G., Driscoll, T. P. & Gillespie, J. J. Cryptic genes for interbacterial antagonism distinguish Rickettsia species infecting blacklegged ticks from other Rickettsia pathogens. Front. Cell Infect. Microbiol. 12, 880813 (2022).
Hagen, R., Verhoeve, V. I., Gillespie, J. J. & Driscoll, T. P. Conjugative transposons and their cargo genes vary across natural populations of Rickettsia buchneri infecting the tick Ixodes scapularis. Genome Biol. Evol. 10, 3218–3229 (2018).
Kurtti, T. J. et al. Rickettsia buchneri sp. nov., a rickettsial endosymbiont of the blacklegged tick Ixodes scapularis. Int. J. Syst. Evol. Microbiol. 65, 965–970 (2015).
Cabezas-Cruz, A., Espinosa, P., Alberdi, P. & de la Fuente, J. Tick–pathogen interactions: the metabolic perspective. Trends Parasitol. 35, 316–328 (2019).
Samaddar, S., Marnin, L., Butler, L. R. & Pedra, J. H. F. Immunometabolism in arthropod vectors: redefining interspecies relationships. Trends Parasitol. 36, 807–815 (2020).
Shaw, D. K. et al. Vector immunity and evolutionary ecology: the harmonious dissonance. Trends Immunol. 39, 862–873 (2018).
Boggs, C. Resource allocation: exploring connections between foraging and life history. Funct. Ecol. 6, 508–518 (1992).
Roff, D. Evolution of Life Histories: Theory and Analysis (Springer Science & Business Media, 1993).
Stearns, S. C., Rose, M. R. & Mueller, L. D. The evolution of life histories. J. Evol. Biol. 6, 304–306 (1992).
Burger, J. R., Hou, C. & Brown, J. H. Toward a metabolic theory of life history. Proc. Natl Acad. Sci. USA 116, 26653–26661 (2019).
Wang, A., Luan, H. H. & Medzhitov, R. An evolutionary perspective on immunometabolism. Science 363, eaar3932 (2019).
Russell, D. G., Huang, L. & VanderVen, B. C. Immunometabolism at the interface between macrophages and pathogens. Nat. Rev. Immunol. 19, 291–304 (2019).
Warburg, O., Posener, K. & Negelein, E. Über den stoffwechsel der carcinomzelle. Naturwissenschaften 12, 1131–1137 (1924).
Ward, P. S. & Thompson, C. B. Metabolic reprogramming: a cancer hallmark even Warburg did not anticipate. Cancer Cell 21, 297–308 (2012).
DeBerardinis, R. J., Lum, J. J., Hatzivassiliou, G. & Thompson, C. B. The biology of cancer: metabolic reprogramming fuels cell growth and proliferation. Cell Metab. 7, 11–20 (2008).
Hall, S. R., Simonis, J. L., Nisbet, R. M., Tessier, A. J. & Cáceres, C. E. Resource ecology of virulence in a planktonic host–parasite system: an explanation using dynamic energy budgets. Am. Nat. 174, 149–162 (2009).
Peyraud, R., Cottret, L., Marmiesse, L., Gouzy, J. & Genin, S. A resource allocation trade-off between virulence and proliferation drives metabolic versatility in the plant pathogen Ralstonia solanacearum. PLoS Pathog. 12, e1005939 (2016).
Hite, J. L., Pfenning, A. C. & Cressler, C. E. Starving the enemy? Feeding behavior shapes host–parasite interactions. Trends Ecol. Evol. 35, 68–80 (2020).
Cressler, C. E., Nelson, W. A., Day, T. & McCauley, E. Disentangling the interaction among host resources, the immune system and pathogens. Ecol. Lett. 17, 284–293 (2014).
Voss, K. et al. A guide to interrogating immunometabolism. Nat. Rev. Immunol. 21, 637–652 (2021).
Song, X., Zhong, Z., Gao, L., Weiss, B. L. & Wang, J. Metabolic interactions between disease-transmitting vectors and their microbiota. Trends Parasitol. 38, 697–708 (2022).
Hoxmeier, J. C. et al. Metabolomics of the tick–Borrelia interaction during the nymphal tick blood meal. Sci. Rep. 7, 1–11 (2017).
Cabezas-Cruz, A., Alberdi, P., Valdes, J. J., Villar, M. & de la Fuente, J. Anaplasma phagocytophilum infection subverts carbohydrate metabolic pathways in the tick vector, Ixodes scapularis. Front. Cell Infect. Microbiol. 7, 23 (2017).
Alberdi, P. et al. The redox metabolic pathways function to limit Anaplasma phagocytophilum infection and multiplication while preserving fitness in tick vector cells. Sci. Rep. 9, 13236 (2019).
Dahmani, M., Anderson, J. F., Sultana, H. & Neelakanta, G. Rickettsial pathogen uses arthropod tryptophan pathway metabolites to evade reactive oxygen species in tick cells. Cell. Microbiol. 22, e13237 (2020).
Namjoshi, P., Dahmani, M., Sultana, H. & Neelakanta, G. Rickettsial pathogen inhibits tick cell death through tryptophan metabolite mediated activation of p38 MAP kinase. iScience 26, 105730 (2023).
Villar, M. et al. Integrated metabolomics, transcriptomics and proteomics identifies metabolic pathways affected by Anaplasma phagocytophilum infection in tick cells. Mol. Cell. Proteomics 14, 3154–3172 (2015).
Mookerjee, S. A., Gerencser, A. A., Nicholls, D. G. & Brand, M. D. Quantifying intracellular rates of glycolytic and oxidative ATP production and consumption using extracellular flux measurements. J. Biol. Chem. 292, 7189–7207 (2017).
Nicholls, D. G. et al. Bioenergetic profile experiment using C2C12 myoblast cells. J. Vis. Exp. 46, e2511 (2010).
Munderloh, U. G., Liu, Y., Wang, M., Chen, C. & Kurtti, T. J. Establishment, maintenance and description of cell lines from the tick Ixodes scapularis. J. Parasitol. 80, 533–543 (1994).
Troughton, D. R. & Levin, M. L. Life cycles of seven ixodid tick species (Acari: Ixodidae) under standardized laboratory conditions. J. Med. Entomol. 44, 732–740 (2007).
Kocan, K. M., de la Fuente, J. & Coburn, L. A. Insights into the development of Ixodes scapularis: a resource for research on a medically important tick species. Parasit. Vectors 8, 592 (2015).
Troha, K. & Ayres, J. S. Metabolic adaptations to infections at the organismal level. Trends Immunol. 41, 113–125 (2020).
Rosenberg, G., Riquelme, S., Prince, A. & Avraham, R. Immunometabolic crosstalk during bacterial infection. Nat. Microbiol. 7, 497–507 (2022).
Thapa, S., Zhang, Y. & Allen, M. S. Bacterial microbiomes of Ixodes scapularis ticks collected from Massachusetts and Texas, USA. BMC Microbiol. 19, 138 (2019).
Van Treuren, W. et al. Variation in the microbiota of Ixodes ticks with regard to geography, species, and sex. Appl. Environ. Microbiol. 81, 6200–6209 (2015).
Roberts, L. D. et al. β-aminoisobutyric acid induces browning of white fat and hepatic β-oxidation and is inversely correlated with cardiometabolic risk factors. Cell Metab. 19, 96–108 (2014).
Tanianskii, D. A., Jarzebska, N., Birkenfeld, A. L., O’Sullivan, J. F. & Rodionov, R. N. β-aminoisobutyric acid as a novel regulator of carbohydrate and lipid metabolism. Nutrients 11, 524 (2019).
Sharma, A. et al. Cas9-mediated gene editing in the black-legged tick, Ixodes scapularis, by embryo injection and ReMOT Control. iScience 25, 103781 (2022).
Sawada, M., Yamamoto, H., Ogasahara, A., Tanaka, Y. & Kihara, S. β-aminoisobutyric acid protects against vascular inflammation through PGC-1β-induced antioxidative properties. Biochem. Biophys. Res. Commun. 516, 963–968 (2019).
Kitase, Y. et al. β-aminoisobutyric acid, BAIBA, is a muscle-derived osteocyte survival factor. Cell Rep. 22, 1531–1544 (2018).
Zhu, X. W., Ding, K., Dai, X. Y. & Ling, W. Q. β-aminoisobutyric acid accelerates the proliferation and differentiation of MC3T3-E1 cells via moderate activation of ROS signaling. J. Chin. Med. Assoc. 81, 611–618 (2018).
Alasmari, S. & Wall, R. Determining the total energy budget of the tick Ixodes ricinus. Exp. Appl. Acarol. 80, 531–541 (2020).
Corona, A. & Schwartz, I. Borrelia burgdorferi: carbon metabolism and the tick-mammal enzootic cycle. Microbiol. Spectr. 3, 10 (2015).
Rikihisa, Y. Mechanisms of obligatory intracellular infection with Anaplasma phagocytophilum. Clin. Microbiol. Rev. 24, 469–489 (2011).
Driscoll, T. P. et al. Wholly Rickettsia! reconstructed metabolic profile of the quintessential bacterial parasite of eukaryotic cells. MBio 8, e00859–17 (2017).
Dumler, J. S. et al. Reorganization of genera in the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales: unification of some species of Ehrlichia with Anaplasma, Cowdria with Ehrlichia and Ehrlichia with Neorickettsia, descriptions of six new species combinations and designation of Ehrlichia equi and ‘HGE agent’ as subjective synonyms of Ehrlichia phagocytophila. Int. J. Syst. Evol. Microbiol. 51, 2145–2165 (2001).
Narasimhan, S. et al. Grappling with the tick microbiome. Trends Parasitol. 37, 722–733 (2021).
Gillespie, J. J. et al. A Rickettsia genome overrun by mobile genetic elements provides insight into the acquisition of genes characteristic of an obligate intracellular lifestyle. J. Bacteriol. 194, 376–394 (2012).
Xiong, Q., Lin, M., Huang, W. & Rikihisa, Y. Infection by Anaplasma phagocytophilum requires recruitment of low-density lipoprotein cholesterol by flotillins. MBio 10, e02783–18 (2019).
Villar, M. et al. Identification and characterization of Anaplasma phagocytophilum proteins involved in infection of the tick vector, Ixodes scapularis. PLoS ONE 10, e0137237 (2015).
Villar, M. et al. The intracellular bacterium Anaplasma phagocytophilum selectively manipulates the levels of vertebrate host proteins in the tick vector Ixodes scapularis. Parasit. Vectors 9, 467 (2016).
Truchan, H. K. et al. Anaplasma phagocytophilum Rab10-dependent parasitism of the trans-Golgi network is critical for completion of the infection cycle. Cell. Microbiol. 18, 260–281 (2016).
Shi, C. X. et al. β-aminoisobutyric acid attenuates hepatic endoplasmic reticulum stress and glucose/lipid metabolic disturbance in mice with type 2 diabetes. Sci. Rep. 6, 21924 (2016).
Audzeyenka, I. et al. β-aminoisobutyric acid (L-BAIBA) is a novel regulator of mitochondrial biogenesis and respiratory function in human podocytes. Sci. Rep. 13, 766 (2023).
Oliva Chávez, A. S. et al. Tick extracellular vesicles enable arthropod feeding and promote distinct outcomes of bacterial infection. Nat. Commun. 12, 3696 (2021).
Yoshiie, K., Kim, H. Y., Mott, J. & Rikihisa, Y. Intracellular infection by the human granulocytic ehrlichiosis agent inhibits human neutrophil apoptosis. Infect. Immun. 68, 1125–1133 (2000).
Labandeira-Rey, M. & Skare, J. T. Decreased infectivity in Borrelia burgdorferi strain B31 is associated with loss of linear plasmid 25 or 28-1. Infect. Immun. 69, 446–455 (2001).
Shaw, D. K. et al. Infection-derived lipids elicit an immune deficiency circuit in arthropods. Nat. Commun. 8, 14401 (2017).
Collet, T.-H. et al. A metabolomic signature of acute caloric restriction. J. Clin. Endocrinol. Metab. 102, 4486–4495 (2017).
Evans, A. et al. High resolution mass spectrometry improves data quantity and quality as compared to unit mass resolution mass spectrometry in high-throughput profiling metabolomics. Metabolomics 4, 1 (2014).
DeHaven, C. D., Evans, A. M., Dai, H. & Lawton, K. A. Organization of GC/MS and LC/MS metabolomics data into chemical libraries. J. Cheminform. 2, 9 (2010).
Sidak-Loftis, L. C. et al. The unfolded-protein response triggers the arthropod immune deficiency pathway. MBio 13, e00703–e00722 (2022).
Acknowledgements
We thank J. Gillespie (University of Maryland, Baltimore) and T. Driscoll (West Virginia University) for sharing primer details to measure R. buchneri, E. E. McClure Carroll (University of Maryland School of Medicine) for schematics, M. Noto and A. Tyler (University of Maryland School of Medicine) for providing instrumentation, H. Hammond for administrative support, A. S. Oliva Chavez (University of Wisconsin) for technical insights, and the Biopolymer/Genomics core facility for Sanger sequencing and the Seahorse metabolic flux assay (S10OD025101). This work was supported by grants from the NIH to A.J.O’N. (F31AI152215); H.J.L.-Y. (T32AI162579); L.R.B. (F31AI167471); D.K.S. (R01AI162819); J.H.F.P. (R01AI134696, R01AI116523, R01AI049424); J.H.F.P., E.F. and U.P. (P01AI138949); and U.P. (R01AI080615). J.H.F.P. was also supported in kind by the Fairbairn Family Lyme Research Initiative. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH, the Department of Health and Human Services or the US Government.
Author information
Authors and Affiliations
Contributions
S.S., A.R., A.J.O'N. and J.H.F.P. conceptualized the study. S.S., A.R., A.J.O'N., H.J.L.-Y., L.M., N.S., X.W., B.K., B.C., K.L.R., J.O. and S.N. performed the experiments. P.R., C.K., F.E.C.P., L.V., L.R.B. and C.R.F. aided in experiments. E.F., U.G.M., U.P., G.M.F., D.K.S. and B.M.P. supervised experiments. S.S., A.R., A.J.O'N., H.J.L.-Y. and J.H.F.P. wrote the manuscript. All authors analysed the data, provided intellectual input into the study and contributed to editing of the manuscript. J.H.F.P. supervised and managed the entire project.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Microbiology thanks Flaminia Catteruccia and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data
Extended Data Fig. 1 Drug susceptibility of tick cell lines.
Cell viability (%) of (a-e) I. scapularis (IDE12), (f-j) Amblyomma americanum (AAE2) and (k-o) Dermacentor andersoni (DAE100) cell lines treated with different inhibitor concentrations for 48 hours (n = 5 for each condition; n represents individual culture wells). Purple bars indicate non-significant, whereas red bars denote significant differences in cell viability compared to untreated control (grey). Data are representative of two independent experiments with mean ± SEM. Statistical significance was calculated by one-way ANOVA followed by Dunnett’s multiple comparison test. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 2 Growth kinetics of A. phagocytophilum and R. buchneri in ISE6 cells under Seahorse conditions.
(a) Schematic of the infection assay. ISE6 cells were cultured in L15C300 complete medium. Upon infection with A. phagocytophilum or R. buchneri at multiplicity of infection (MOI) 50 or 100, the L15C300 medium was replaced with the modified L15C (mL15C) medium on day 0. Bacterial infection was assessed at 1, 24 and 48 hours post-infection by RT-qPCR. (b-c) A. phagocytophilum infection for (b) MOI 50 or (c) MOI 100, quantified by amplification of 16 s rRNA gene (n = 10 for each condition; n represents individual culture wells). (d-e) R. buchneri infection for (d) MOI 50 or (e) MOI 100, measured using the citrate synthase (gltA) gene (n = 10 for each condition; n represents individual culture wells). Data were normalized to 1 hr, and tick actin was used as a housekeeping gene. Data are representative of two independent experiments with mean ± SEM. Statistical significance was evaluated by (b, d-e) Kruskal Wallis followed by Dunn’s multiple comparison test or (c) one-way ANOVA followed by Dunnett’s multiple comparison test. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 3 A. phagocytophilum infection in response to bioenergetic alterations.
(a) Schematic of microbial infection upon glycolysis or OxPhos inhibitor treatment in vitro. 1 × 106 ISE6 cells were treated with 50 mM 2-deoxy-D-glucose (2-DG), 0.1 µM rotenone (Rot), 0.5 µM antimycin (Anti), 0.5 µM oligomycin (Oligo) or 20 µM 2,4-dinitrophenol (2,4-DNP) for 1 hour prior to infection with A. phagocytophilum at MOI 50. Cells were collected 2 days post-infection for bacterial quantification. Infected cells without inhibitor treatment (-) served as a control. (b) A. phagocytophilum infection quantified by amplification of 16 S rRNA gene (n = 5 for each condition; n represents individual culture wells). (c) Experimental design of inhibitor treatment on A. phagocytophilum infection in vivo. Created with BioRender.com. (d-e) Ticks were injected with either PBS (-, grey) or 2-DG (purple) at indicated amounts prior to feeding on A. phagocytophilum-infected C57BL/6 mice. (d) Tick weight (n = 17, 29, 14 and 21) and (e) A. phagocytophilum infection (n = 7, 17, 7 and 12) were recorded. (f-g) Ticks were injected with either PBS (-, grey) or 0.8 pmol oligomycin (orange) prior to feeding on A. phagocytophilum-infected C57BL/6 mice. (f) Tick weight (n = 27 and 31) and (g) A. phagocytophilum infection (n = 10 and 12) were measured. (b, d-g) Data are representative of two independent experiments with mean ± SEM. Statistical significance was evaluated by (b, d-e) Kruskal–Wallis test followed by Dunn’s multiple comparisons test or (f-g) two-sided Mann-Whitney test. NS=not significant. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 4 R. buchneri infection in response to bioenergetic alterations.
(a) Schematic of microbial infection upon glycolysis or OxPhos inhibitor treatment. 1 × 106 ISE6 cells were treated with 50 mM 2-deoxy D-glucose (2-DG), 0.1 µM rotenone (Rot), 0.5 µM antimycin (Anti), 0.5 µM oligomycin (Oligo) or 20 µM 2,4-dinitrophenol (2,4-DNP) for 1 hour prior to infection with R. buchneri at MOI 50. Cells were collected 2 days post-infection for bacterial quantification via RT-qPCR. Infected cells without inhibitor treatment (-) served as controls. (b) R. buchneri infection was measured using the citrate synthase (gltA) gene by RT-qPCR (n = 6 for each condition, n represents individual culture wells). Data are representative of two independent experiments with mean ± SEM. Statistical significance was evaluated by Kruskal Wallis test followed by Dunn’s multiple comparisons test. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 5 Attachment of ticks silenced for genes associated with the D-BAIBA metabolism.
I. scapularis nymphs were injected with siRNA or scrambled control for beta-ureidopropionase 1 (upb1) or alanine-glyoxylate aminotransferase 2 (agxt2) and allowed to feed on uninfected C57BL/6 mice for 3 days. The attachment of silenced ticks compared to scrambled controls was recorded for (a) upb1 (n = 69 and 83) or (b) agxt2 (n = 76 and 110). Data are representative of two independent experiments where n = an individual tick. Statistical significance was evaluated by the Fisher’s exact test. NS=not significant. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 6 Effect of abat silencing on tick fitness.
(a-d) I. scapularis nymphs were injected with siRNA (blue) or scrambled control (grey) for 4-aminobutyrate aminotransferase (abat) and allowed to feed on uninfected C57BL/6 mice for 3 days. Fitness parameters were recorded. (a) Silencing efficiency (n = 11 and 10); (b) tick attachment (n = 76 and 81); (c) weight (n = 37 and 34); and (d) survival (n = 30 and 31). (a-d) Data are representative of two independent experiments with mean ± SEM where n = an individual tick. Statistical significance was evaluated by (a, c) two-sided t-test with Welch’s correction for unequal variances (b) Fisher’s exact test (d) Log-rank (Mantel-Cox). NS = not significant. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 7 Fitness parameters in ticks silenced for genes related to D-BAIBA metabolism during A. phagocytophilum acquisition.
(a-d) Nymphs were injected with siRNA or scrambled control for genes involved in D-BAIBA metabolism and allowed to feed on A. phagocytophilum-infected mice for 3 days. (a-b) Effect of beta-ureidopropionase 1 (upb1) silencing on (a) attachment (n = 100 and 150) and (b) weight (n = 33 and 22) of fed ticks compared to the scrambled control treatment. (c-d) Effect of alanine-glyoxylate aminotransferase 2 (agxt2) silencing on (c) attachment (n = 146 and 100) and (d) weight (n = 38 and 35) of fed ticks compared to the scrambled control treatment. (a-d) Data are representative of two independent experiments with mean ± SEM where n= an individual tick. Statistical significance was evaluated by (a, c) Fisher’s exact test or (b, d) two-sided unpaired t-test with Welch’s correction. NS=not significant. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 8 Fitness in ticks microinjected with BAIBA and chronically infected with A. phagocytophilum.
Uninfected (Un) or chronically infected (In) A. phagocytophium nymphs were injected with 40 pmol of β-aminoisobutyric acid (BAIBA) or isomer and allowed to feed on C57BL/6 mice for 3 days. (a) Tick attachment to the mammalian host (n = 93,108, 102 and 97); (b) tick weight (n = 62, 64, 45 and 38) and (c) A. phagocytophilum quantification by amplification of the 16 S rRNA gene (n = 12 and 11). (a-c) Data are representative of two independent experiments with mean ± SEM where n = an individual tick. Statistical significance was evaluated by (a) Fisher’s exact test, (b) two-sided Mann-Whitney test or (c) two-sided unpaired t-test with Welch’s correction. NS = not significant. Significant p values (<0.05) are displayed in the figure.
Extended Data Fig. 9 Contribution of BAIBA to A. phagocytophilum infection in ticks.
Proposed crosstalk between the infection cycle of A. phagocytophilum (brown) and I. scapularis metabolic pathways. Infection induces an expensive host process, and energy is partially supplied by rapid ATP generation through increased glycolysis and conversion of pyruvate to lactate (carbohydrate metabolism, green). Infection with A. phagocytophilum increases fatty acid, cholesterol, and phospholipids levels in the host cell, which are utilized for membrane restructuring and inclusion membrane synthesis during bacterium replication (lipid metabolism, yellow). A. phagocytophilum enhances proteolysis in the host cell and acquires amino acids through ER-dependent trans-Golgi network (TGN) vesicles, scavenging essential amino acids that the bacterium uses for synthesizing its own virulence factors and structural proteins (protein metabolism, blue). A. phagocytophilum also acquires nucleotides and their derivatives from the host to synthesize DNA and RNA for replication (nucleotide metabolism, purple). Finally, A. phagocytophilum synthesizes vitamins and cofactors during the infection cycle which serves as a supplementary source of nutrients for the host (vitamins and cofactors, orange). β-aminoisobutyric acid (BAIBA) acts as a key metabolite, playing pleiotropic roles by connecting the four major metabolic pathways altered by A. phagocytophilum infection: nucleotide, protein, lipid and carbohydrate pathways. Fine-tuned regulation of BAIBA metabolism is required to balance infection and fitness costs in I. scapularis. Figure created with BioRender.com.
Supplementary information
Supplementary Information
Supplementary Figs. 1–9.
Supplementary Table
Supplementary Table 1 Primers and siRNA sequences. Supplementary Table 2 Resources and reagents.
Supplementary Data
Statistical source data for supplementary figures.
Source data
Source Data Fig. 1
Statistical source data.
Source Data Fig. 2
Statistical source data.
Source Data Fig. 3
Statistical source data.
Source Data Fig. 4
Statistical source data.
Source Data Fig. 5
Statistical source data.
Source Data Fig. 6
Statistical source data.
Source Data Extended Data Fig. 1
Statistical source data.
Source Data Extended Data Fig. 2
Statistical source data.
Source Data Extended Data Fig. 3
Statistical source data.
Source Data Extended Data Fig. 4
Statistical source data.
Source Data Extended Data Fig. 5
Statistical source data.
Source Data Extended Data Fig. 6
Statistical source data.
Source Data Extended Data Fig. 7
Statistical source data.
Source Data Extended Data Fig. 8
Statistical source data.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Samaddar, S., Rolandelli, A., O’Neal, A.J. et al. Bacterial reprogramming of tick metabolism impacts vector fitness and susceptibility to infection. Nat Microbiol 9, 2278–2291 (2024). https://doi.org/10.1038/s41564-024-01756-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41564-024-01756-0
This article is cited by
-
Bacteria induce metabolic perturbations in ticks
Nature Microbiology (2024)