scholarly journals Tick Saliva Reduces Adherence and Area of Human Neutrophils

2004 ◽  
Vol 72 (5) ◽  
pp. 2989-2994 ◽  
Author(s):  
Ruth R. Montgomery ◽  
Denise Lusitani ◽  
Anne de Boisfleury Chevance ◽  
Stephen E. Malawista

ABSTRACT During natural infection with the agent of Lyme disease, Borrelia burgdorferi, spirochetes are delivered with vector saliva, which contains anti-inflammatory and antihemostatic activities. We show here that the saliva of ixodid ticks reduces polymorphonuclear leukocyte (PMN) adhesion via downregulation of β2-integrins and decreases the efficiency of PMN in the uptake and killing of spirochetes. Inhibition of integrin adhesion and signaling reduces anti-inflammatory functions of PMN. These effects may favor the initial survival of spirochetes in vivo.

2019 ◽  
Vol 93 (3) ◽  
pp. 196-202 ◽  
Author(s):  
Kevin S. Brandt ◽  
Amy J. Ullmann ◽  
Claudia R. Molins ◽  
Kalanthe Horiuchi ◽  
Brad J. Biggerstaff ◽  
...  

Parasitology ◽  
2016 ◽  
Vol 143 (10) ◽  
pp. 1310-1319 ◽  
Author(s):  
SANNE C. RUYTS ◽  
EVY AMPOORTER ◽  
ELENA C. COIPAN ◽  
LANDER BAETEN ◽  
DIETER HEYLEN ◽  
...  

SUMMARYLyme disease is caused by bacteria of theBorrelia burgdorferigenospecies complex and transmitted by Ixodid ticks. In North America only one pathogenic genospecies occurs, in Europe there are several. According to the dilution effect hypothesis (DEH), formulated in North America, nymphal infection prevalence (NIP) decreases with increasing host diversity since host species differ in transmission potential. We analysedBorreliainfection in nymphs from 94 forest stands in Belgium, which are part of a diversification gradient with a supposedly related increasing host diversity: from pine stands without to oak stands with a shrub layer. We expected changing tree species and forest structure to increase host diversity and decrease NIP. In contrast with the DEH, NIP did not differ between different forest types. Genospecies diversity however, and presumably also host diversity, was higher in oak than in pine stands. Infected nymphs tended to harbourBorrelia afzeliiinfection more often in pine stands whileBorrelia gariniiandBorrelia burgdorferiss. infection appeared to be more prevalent in oak stands. This has important health consequences, since the latter two cause more severe disease manifestations. We show that the DEH must be nuanced for Europe and should consider the response of multiple pathogenic genospecies.


2019 ◽  
Author(s):  
Chunxiang Bai ◽  
Hua Yang ◽  
Peng Cui ◽  
Rong Quan ◽  
Ying Zhang

AbstractBorrelia burgdorferi could be occasionally recovered from patients after antibiotic treatment, which indicates it may resist eradication by antibiotic and host defense mechanisms. Skin fibroblast cells have previously been shown to protect the killing of B. burgdorferi by ceftriaxone, a powerful antibiotic commonly used to treat Lyme disease. In this study, we evaluated if fibroblast cells could also protect against the doxycycline+ cefuroxime+ daptomycin drug combination which has previously been shown to completely eradicate highly persistent biofilm-like microcolonies of B. burgdorferi. To do so, we utilized a GFP-labeled B. burgdorferi for infection of murine fibroblast cells and assessed the effect of the drug combination on killing the bacteria in the presence or absence of the fibroblast cells. Surprisingly, we found that fibroblasts could protect B. burgdorferi from being completely killed by the drug combination doxycycline, cefuroxime and daptomycin, which eradicated B. burgdorferi completely in the absence of fibroblast cells. Interestingly, addition of essential oil carvacrol or oregano at 0.1% could enhance the activity of the doxycycline+ cefuroxime+ daptomycin drug combination and led to complete eradication of B. burgdorferi even in the presence of fibroblast cells. Further studies are needed to determine if the essential oil drug combinations could eradicate persistent B. burgdorferi infection in vivo in animal models. Our study provides a useful and convenient ex vivo model for evaluating different drug regimens needed for developing more effective treatment of persistent Lyme disease in the future.


2006 ◽  
Vol 74 (4) ◽  
pp. 2468-2472 ◽  
Author(s):  
Ruth R. Montgomery ◽  
Kimberly Schreck ◽  
Xiaomei Wang ◽  
Stephen E. Malawista

ABSTRACT Borrelia burgdorferi, the spirochetal agent of Lyme disease, is susceptible to killing by a variety of polymorphonuclear leukocyte (PMN) components. Some are most effective against metabolically active B. burgdorferi. The abundant PMN cytoplasmic protein calprotectin, elevated 10- to 100-fold in inflammation, inhibits the growth of spirochetes through chelation of the essential cation, Zn. Since the action of some therapeutic antibiotics depends on bacterial division, we investigated the antibiotic sensitivities of spirochetes in calprotectin. In physiologic calprotectin, B. burgdorferi is not eliminated by therapeutic doses of penicillin G; in contrast, doxycycline is effective. Calprotectin may modify the clearance of spirochetes at sites of inflammation.


Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3382 ◽  
Author(s):  
Chi-Lung Yang ◽  
Ho-Cheng Wu ◽  
Tsong-Long Hwang ◽  
Chu-Hung Lin ◽  
Yin-Hua Cheng ◽  
...  

One new dibenzocycloheptene, validinol (1), and one butanolide firstly isolated from the natural source, validinolide (2), together with 17 known compounds were isolated from the stem of Cinnamomum validinerve. Among the isolates, lincomolide A (3), secosubamolide (7), and cinnamtannin B1 (19) exhibited potent inhibition on both superoxide anion generation (IC50 values of 2.98 ± 0.3 µM, 4.37 ± 0.38 µM, and 2.20 ± 0.3 µM, respectively) and elastase release (IC50 values of 3.96 ± 0.31 µM, 3.04 ± 0.23 µM, and 4.64 ± 0.71 µM, respectively) by human neutrophils. In addition, isophilippinolide A (6), secosubamolide (7), and cinnamtannin B1 (19) showed bacteriostatic effects against Propionibacterium acnes in in vitro study, with minimal inhibitory concentration (MIC) values at 16 μg/mL, 16 μg/mL, and 500 μg/mL, respectively. Further investigations using the in vivo ear P. acnes infection model showed that the intraperitoneal administration of the major component cinnamtannin B1 (19) reduced immune cell infiltration and pro-inflammatory cytokines TNF-α and IL-6 at the infection sites. The results demonstrated the potential of cinnamtannin B1 (19) for acne therapy. In summary, these results demonstrated the anti-inflammatory potentials of Formosan C. validinerve during bacterial infections.


2007 ◽  
Vol 76 (1) ◽  
pp. 391-402 ◽  
Author(s):  
Mahulena Maruskova ◽  
M. Dolores Esteve-Gassent ◽  
Valerie L. Sexton ◽  
J. Seshu

ABSTRACT Borrelia burgdorferi, the causative agent of Lyme disease, undergoes rapid adaptive gene expression in response to environmental signals encountered during different stages of its life cycle in the arthropod vector or the mammalian host. Among all the plasmid-encoded genes of B. burgdorferi, several linear plasmid 54 (lp54)-encoded open reading frames (ORFs) exhibit the greatest differential expression in response to mammalian host-specific temperature, pH, and other uncharacterized signals. These ORFs include members of the paralogous gene family 54 (pgf 54), such as BBA64, BBA65, and BBA66, present on lp54. In an attempt to correlate transcriptional up-regulation of these pgf 54 members to their role in infectivity, we inactivated BBA64 and characterized the phenotype of this mutant both in vitro and in vivo. There were no major differences in the protein profiles between the BBA64 mutant and the control strains, while immunoblot analysis indicated that inactivation of BBA64 resulted in increased levels of BBA65. Moreover, there was no significant difference in the ability of the BBA64 mutant to infect C3H/HeN mice compared to that of its parental or complemented control strains as determined by culturing of viable spirochetes from infected tissues. However, enumeration of spirochetes using quantitative real-time PCR revealed tissue-specific differences, suggesting a minimal role for BBA64 in the survival of B. burgdorferi in select tissues. Infectivity analysis of the BBA64 mutant suggests that B. burgdorferi may utilize multiple determinants to establish infection in mammalian hosts.


2011 ◽  
Vol 18 (6) ◽  
pp. 901-906 ◽  
Author(s):  
Christopher G. Earnhart ◽  
DeLacy V. L. Rhodes ◽  
Richard T. Marconi

ABSTRACTBorrelia burgdorferiOspC is an outer membrane lipoprotein required for the establishment of infection in mammals. Due to its universal distribution amongB. burgdorferisensu lato strains and high antigenicity, it is being explored for the development of a next-generation Lyme disease vaccine. An understanding of the surface presentation of OspC will facilitate efforts to maximize its potential as a vaccine candidate. OspC forms homodimers at the cell surface, and it has been hypothesized that it may also form oligomeric arrays. Here, we employ site-directed mutagenesis to test the hypothesis that interdimeric disulfide bonds at cysteine 130 (C130) mediate oligomerization.B. burgdorferiB31ospCwas replaced with a C130A substitution mutant to yield strain B31::ospC(C130A). Recombinant protein was also generated. Disulfide-bond-dependent oligomer formation was demonstrated and determined to be dependent on C130. Oligomerization was not required forin vivofunction, as B31::ospC(C130A) retained infectivity and disseminated normally. The total IgG response and the induced isotype pattern were similar between mice infected with untransformed B31 and those infected with the B31::ospC(C130A) strain. These data indicate that the immune response to OspC is not significantly altered by formation of OspC oligomers, a finding that has significant implications in Lyme disease vaccine design.


1998 ◽  
Vol 66 (5) ◽  
pp. 2143-2153 ◽  
Author(s):  
Mark S. Hanson ◽  
David R. Cassatt ◽  
Betty P. Guo ◽  
Nita K. Patel ◽  
Michael P. McCarthy ◽  
...  

ABSTRACT Borrelia burgdorferi, the spirochete that causes Lyme disease, binds decorin, a collagen-associated extracellular matrix proteoglycan found in the skin (the site of entry for the spirochete) and in many other tissues. Two borrelial adhesins that recognize this proteoglycan, decorin binding proteins A and B (DbpA and DbpB, respectively), have recently been identified. Infection of mice by low-dose B. burgdorferi challenge elicited antibodies against DbpA and DbpB that were sustained at high levels, suggesting that these antigens are expressed in vivo. Scanning immunoelectron microscopy showed that DbpA was surface accessible on intact borreliae. Passive administration of DbpA antiserum protected mice from infection following challenge with heterologous B. burgdorferi sensu stricto isolates, even when serum administration was delayed for up to 4 days after challenge. DbpA is the first antigen target identified that is capable of mediating immune resolution of early, localizedB. burgdorferi infections. DbpA immunization also protected mice from B. burgdorferi challenge; DbpB immunization was much less effective. DbpA antiserum inhibited in vitro growth of manyB. burgdorferi sensu lato isolates of diverse geographic, phylogenetic, and clinical origins. In combination, these findings support a role for DbpA in the immunoprophylaxis of Lyme disease and suggest that DbpA vaccines have the potential to eliminate early-stageB. burgdorferi infections.


1998 ◽  
Vol 66 (7) ◽  
pp. 3433-3435 ◽  
Author(s):  
Juha Suhonen ◽  
Kaija Hartiala ◽  
Matti K. Viljanen

ABSTRACT Interactions between human neutrophils and Borrelia burgdorferi, the Lyme disease spirochete, were studied by dark-field microscopy combined with video technology. A previously unrecognized mechanism for neutrophils to phagocytize the spirochete was discovered. During phagocytosis, the spirochete attaches to the neutrophil head-on, the neutrophil forms a thin tubelike protrusion around the bacterium, and the fully covered spirochete is drawn into the cell.


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