scholarly journals Borrelia burgdorferi Gene Expression In Vivo and Spirochete Pathogenicity

2000 ◽  
Vol 68 (3) ◽  
pp. 1222-1230 ◽  
Author(s):  
Juan Anguita ◽  
Swapna Samanta ◽  
Beatriz Revilla ◽  
Kyoungho Suk ◽  
Subrata Das ◽  
...  

ABSTRACT Borrelia burgdorferi spirochetes that do not cause arthritis or carditis were developed and used to investigate Lyme disease pathogenesis. A clonal isolate of B. burgdorferiN40 (cN40), which induces disease in C3H/HeN (C3H) mice, was repeatedly passaged in vitro to generate nonpathogenic spirochetes. The passage 75 isolate (N40-75) was infectious for C3H mice but did not cause arthritis or carditis, and spirochetes were at low levels or absent in the joints or hearts, respectively. N40-75 could, however, cause disease in severe combined immunodeficient (SCID) mice, suggesting that the response in immunocompetent mice prevented effective spirochete dissemination and the subsequent development of arthritis and carditis. Administration of immune sera at 4 days after spirochete challenge aborted N40-75, but not cN40, infection in SCID mice. A B. burgdorferi genomic expression library was differentially probed with sera from cN40- and N40-75-infected mice, to identify genes that may not be effectively expressed by N40-75 in vivo. N40-75 was defective in the up-regulation of several genes that are preferentially expressed during mammalian infection, including dbpAB,bba64, and genes that map to the cp32 family of plasmids. These data suggest that adaptation and gene expression may be required for B. burgdorferi to effectively colonize the host, evade humoral responses, and cause disease.

2000 ◽  
Vol 68 (7) ◽  
pp. 4169-4173 ◽  
Author(s):  
Sunlian Feng ◽  
Emir Hodzic ◽  
Stephen W. Barthold

ABSTRACT A 37-kDa protein from Borrelia burgdorferi (the agent of Lyme disease) was identified as a target for immune-mediated resolution of Lyme arthritis. Studies in a mouse model have shown that arthritis resolution can be mediated by antibodies (against unknown target antigens) within immune sera from actively infected mice. Immune sera from infected mice were therefore used to screen a B. burgdorferi genomic expression library. A gene was identified whose native product is a putative lipoprotein of approximately 37 kDa, referred to here as arthritis-related protein (Arp). Active and passive immunization of mice with recombinant Arp or Arp antiserum, respectively, did not protect mice from challenge inoculation. However, when Arp antiserum was administered to severe combined immunodeficient (SCID) mice with established infections and with ongoing arthritis and carditis, treatment selectively induced arthritis resolution without affecting the status of carditis or influencing the status of infection, including spirochetemia. The selective arthritis-resolving effect of Arp antiserum mimics the activity of immune serum from immunocompetent mice when such serum is transferred into SCID mice with established infections. The arp gene could not be amplified from unrelated B. burgdorferi isolates but hybridized with those isolates only under very-low-stringency conditions. Arp antiserum reacted against proteins of similar size in a wide range of B. burgdorferi isolates.


1998 ◽  
Vol 66 (8) ◽  
pp. 3689-3697 ◽  
Author(s):  
Jing-Ren Zhang ◽  
Steven J. Norris

ABSTRACT The Lyme disease agent, Borrelia burgdorferi, is able to persistently infect humans and animals for months or years in the presence of an active immune response. It is not known how the organisms survive immune attack in the mammalian host.vlsE, a gene localized near one end of linear plasmid lp28-1 and encoding a surface-exposed lipoprotein in B. burgdorferi B31, was shown recently to undergo extensive genetic and antigenic variation within 28 days of initial infection in C3H/HeN mice. In this study, we examined the kinetics of vlsEsequence variation in C3H/HeN mice at 4, 7, 14, 21, and 28 days and at 7 and 12 months postinfection. Sequence changes were detected by PCR amplification and sequence analysis as early as 4 days postinfection and accumulated progressively in both C3H/HeN and CB-17 severe combined immunodeficient (SCID) mice throughout the course of infection. The sequence changes were consistent with sequential recombination of segments from multiple silent vls cassette sites into thevlsE expression site. No vlsE sequence changes were detected in organisms cultured in vitro for up to 84 days. These results indicate that vlsE recombination is induced by a factor(s) present in the mammalian host, independent of adaptive immune responses. The possible inducing conditions appear to be present in various tissue sites because isolates from multiple tissues showed similar degrees of sequence variation. The rate of accumulation of predicted amino acid changes was higher in the immunologically intact C3H/HeN mice than in SCID mice, a finding consistent with immune selection of VlsE variants.


2022 ◽  
Vol 12 ◽  
Author(s):  
Rui Hu ◽  
Bingqian Zhou ◽  
Zheyi Chen ◽  
Shiyu Chen ◽  
Ningdai Chen ◽  
...  

Protein arginine transferase 5 (PRMT5) has been implicated as an important modulator of tumorigenesis as it promotes tumor cell proliferation, invasion, and metastasis. Studies have largely focused on PRMT5 regulating intrinsic changes in tumors; however, the effects of PRMT5 on the tumor microenvironment and particularly immune cells are largely unknown. Here we found that targeting PRMT5 by genetic or pharmacological inhibition reduced lung tumor progression in immunocompromised mice; however, the effects were weakened in immunocompetent mice. PRMT5 inhibition not only decreased tumor cell survival but also increased the tumor cell expression of CD274 in vitro and in vivo, which activated the PD1/PD-L1 axis and eliminated CD8+T cell antitumor immunity. Mechanistically, PRMT5 regulated CD274 gene expression through symmetric dimethylation of histone H4R3, increased deposition of H3R4me2s on CD274 promoter loci, and inhibition of CD274 gene expression. Targeting PRMT5 reduced this inhibitory effect and promoted CD274 expression in lung cancer. However, PRMT5 inhibitors represent a double-edged sword as they may selectively kill cancer cells but may also disrupt the antitumor immune response. The combination of PRMT5 inhibition and ani-PD-L1 therapy resulted in an increase in the number and enhanced the function of tumor-infiltrating T cells. Our findings address an unmet clinical need in which combining PRMT5 inhibition with anti-PD-L1 therapy could be a promising strategy for lung cancer treatment.


2010 ◽  
Vol 22 (1) ◽  
pp. 297
Author(s):  
L. Jiang ◽  
S. L. Marjani ◽  
M. Bertolini ◽  
H. A. Lewin ◽  
G. B. Anderson ◽  
...  

During the past several decades, in vitro fertilization (IVF) has been increasingly used in animal production and human infertility treatment. In vitro production (IVP) has been shown to cause reduced developmental competence, aberrant gene expression, and developmental abnormalities. Our objective was to determine how in vitro procedures influence global gene expression during fetal development. To this end, we analyzed the gene expression profiles of liver and placentome tissue samples (n = 18) from IVP and in vivo-derived fetuses at Days 90 and 180 of gestation (n = 5 IVP and n = 4 in vivo-derived pregnancies for each day of gestation). Standard in vitro maturation and fertilization protocols were employed. Putative zygotes were co-cultured with bovine oviductal epithelial cells to the blastocyst stage. In vivo embryos were collected 7 days after AI by nonsurgical uterine flushing. Blastocyst-stage IVP and in vivo embryos were transferred to synchronized recipients and monitored until collection at Day 90 or 180. The pregnancy rate at Day 90 was 12% and 27% for IVP and in vivo pregnancies, respectively (Bertolini et al. 2004 Reproduction 128, 341-354). To conduct expression profiling, total RNA from each tissue sample and a standard reference was indirectly labeled with Cy3 and Cy5, respectively, and hybridized in duplicate to custom, bovine 13 K oligonucleotide microarrays. After Loess normalization, a two-way (origin and day) ANOVA model (GeneSpring 7.3.1) was used to identify differentially expressed genes in each tissue. The P-values were adjusted for multiple comparisons using a 5% false discovery rate (FDR). The expression of 11 candidate genes was confirmed independently by quantitative RT-PCR. Surprisingly, in both the liver and placentome tissues, no differential gene expression was detected between the IVP and in vivo fetuses at Day 90 and 180. This was observed even when the FDR was relaxed to 10% and 20%. A total of 879 genes (523 genes ≥ 1.5-fold) were differentially expressed during liver development from 90 to 180 days of gestation. Conversely, no differential gene expression was detected in the placentomes during this developmental period. Our findings show that during early and mid gestation, surviving IVP fetuses had normal patterns of gene expression. It is possible that embryos with less severe perturbations may survive with their gene expression normalized as development proceeds. Additionally, initial changes in gene expression caused by IVP may affect subsequent development, but do not necessarily persist throughout gestation. Present addresses: L. Jiang, Columbia University, New York, NY, USA; S. L. Marjani, Yale University, New Haven, CT, USA; M. Bertolini, University of Fortaleza, CE, Brazil. This work was supported by USDA grants to X.Y, H.A.L., and X.C T.


2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.


2017 ◽  
Vol 95 (3) ◽  
pp. 1313 ◽  
Author(s):  
L. Zhang ◽  
L. F. Schütz ◽  
C. L. Robinson ◽  
M. L. Totty ◽  
L. J. Spicer

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