ライフサイエンスコーパス: A. marginale

1 A. marginale and related ehrlichiae express immunoprotec

2 A. marginale encodes three proteins containing ankyrin m

3 A. marginale establishes lifelong persistence in infecte

4 A. marginale is present in the tick salivary glands befo

5 A. marginale numbers per tick increase gradually in sali

6 A. marginale T4SS proteins VirB2, VirB4-1, VirB4-2, VirB

7 A. marginale thus maintains two large, separate systems

8 All 11 A. marginale isolates collected from Oklahoma had differ

9 ts were identified, which corresponded to 32 A. marginale subsp. centrale genotypes detected in cattl

10 and subolesin control, were found to affect A. marginale infection in IDE8 tick cells.

11 oprotein M, vATPase, and ubiquitin, affected A. marginale infection in different sites of development

12 for induction of protective immunity against A. marginale challenge.

13 ively immunized with outer membranes against A. marginale challenge and identify three MSPs that are

14 uired for vaccine-induced protection against A. marginale and provides clear direction for developmen

15 loped strong CD4(+) T cell responses against A. marginale, MSP1a, and specific MHC class II DR-restri

16 unization, proliferated specifically against A. marginale homogenate and purified MSP1 in a dose-depe

17 smosis and is used as a live vaccine against A. marginale There has been less interest in the epidemi

18 testing as a linked protein vaccine against A. marginale.

19 proteins in development of vaccines against A. marginale and related pathogens.

20 no acid sequences are highly conserved among A. marginale strains, with identities ranging from 95 to

21 onal antibody and expression screening of an A. marginale phage library.

22 -sLe(x) fails to inhibit AmOmpA adhesion and A. marginale infection.

23 , as has been reported with A. marginale and A. marginale subsp. centrale strains.

24 ys to simultaneously detect A. marginale and A. marginale subsp. centrale.

25 ettsial agents Anaplasma phagocytophilum and A. marginale.

26 f AmOmpA and ApOmpA competitively antagonize A. marginale infection of host cells, but a monoclonal a

27 Because A. marginale is an obligate intracellular organism, its

28 The promoters in both A. marginale and A. phagocytophilum have similar structu

29 ect as few as 100 copies of 16S rRNA of both A. marginale and A. phagocytophilum in the same reaction

30 sistence in the chronic infections caused by A. marginale and related rickettsiae.

31 taining ankyrin motifs would be expressed by A. marginale only in tick cells and would traffic to the

32 ere confirmed to be expressed as proteins by A. marginale within infected erythrocytes, with expressi

33 tigenically diverse and continually changing A. marginale population within the blood.

34 In contrast, A. marginale subsp. centrale (Israel vaccine strain) has

35 In contrast, A. marginale subsp. centrale colonized the midgut and th

36 Within each rickettsemic cycle, A. marginale expressing antigenically variant major surf

37 eins (MSPs) between the cell culture-derived A. marginale and the bovine erythrocytic stage, currentl

38 The cell culture-derived A. marginale maintained the same-size MSP1a as that foun

39 eal-time PCR assays to simultaneously detect A. marginale and A. marginale subsp. centrale.

40 results indicate that a genetically distinct A. marginale strain capable of superinfecting the mammal

41 us Florida strain, four genetically distinct A. marginale strains, and Anaplasma ovis.

42 Th cell epitopes among genetically distinct A. marginale strains, Th cell clones obtained prior to c

43 is that transmission of genomically distinct A. marginale strains predominates in high-prevalence are

44 ng genotypically and phenotypically distinct A. marginale, A. ovis, and A. centrale strains.

45 that superinfection does occur with distinct A. marginale strains, as has been reported with A. margi

46 equire responses to an antigenically diverse A. marginale population.

47 marked variation in the abilities of diverse A. marginale strains to assemble the F-actin appendages.

48 During A. marginale infection, dynamic and extensive amino acid

49 New MSP2 variants appeared in each A. marginale population, and sequence alignment of the M

50 different MSP2 variants were encoded in each A. marginale population.

51 cattle with persistent infections of either A. marginale strain.

52 AG2 and OpAG3 were expressed by all examined A. marginale strains during the acute rickettsemia in th

53 ons are highly conserved among the expressed A. marginale variants, and similar sequences define the

54 at loss of memory T cell responses following A. marginale infection is due to a mechanism other than

55 The ratio of 16S rRNA to 16S DNA copies for A. marginale was determined to be 117.9:1 (95% confidenc

56 ervals, similar to the pattern described for A. marginale-infected cattle, while in the second patter

57 utility of msp1aS as a genotypic marker for A. marginale subsp. centrale strain diversity.

58 Samples positive for A. marginale subsp. centrale were further characterized

59 Two calves seronegative for A. marginale were immunized four times, at weeks 0, 3, 7

60 The suppressed response was specific for A. marginale, as responses to Clostridium vaccine Ag wer

61 Thus, an effective vaccine for A. marginale and related organisms should contain both T

62 MSP1a among geographic A. marginale isolates is variable in size because of dif

63 reservoirs harbor genetically heterogeneous A. marginale and suggest that different genotypes are ma

64 Within the mammalian host, A. marginale generates antigenic variants by changing a

65 To identify A. marginale molecules associated with these filaments,

66 nated the major surface protein 2 (MSP-2) in A. marginale and HGE and OMP-1 in E. chaffeensis.

67 As in A. marginale, the msp2(p44) gene in this expression site

68 Antibody was induced early in A. marginale infection, predominately against the surfac

69 E. coli were also shown to be functional in A. marginale infected cells, as determined by quantifica

70 LAG-3(+) exhausted T cells were monitored in A. marginale-challenged cattle previously immunized with

71 In this study we analyzed MSP2 in A. marginale populations from the salivary glands of mal

72 ity at the protein level) was higher than in A. marginale.

73 , these superfamily genes are transcribed in A. marginale-infected erythrocytes, tick midgut and sali

74 mpA or its predicted binding domain inhibits A. marginale infection of host cells.

75 to the diversity among strains of senso lato A. marginale.

76 A key question is how the small 1.2 Mb A. marginale genome generates sufficient variants to all

77 cterized by rickettsemic cycles in which new A. marginale variant types, defined by the sequence of t

78 Nonetheless, A. marginale subsp. centrale was not transmitted, even w

79 The ability of A. marginale to persist in cattle has been shown to be d

80 Glycosylation may play a role in adhesion of A. marginale to tick cells because chemical deglycosylat

81 ion of MSP1a plays a role in the adhesion of A. marginale to tick cells.

82 ylation of MSP1a plays a role in adhesion of A. marginale to tick cells.

83 hia ewingii reacted with the MSP3 antigen of A. marginale.

84 is not a marker for the characterization of A. marginale geographic isolates and suggest that the ge

85 a (MSP1a) and MSP1b form the MSP1 complex of A. marginale, which is involved in adhesion of the patho

86 The surface complexes of A. marginale isolated from erythrocytes of the mammalian

87 se PCR (qRT-PCR) assays for the detection of A. marginale and A. phagocytophilum 16S rRNA in plasma-f

88 ol for the accurate and precise detection of A. marginale and A. phagocytophilum infections in cattle

89 itivity and specificity for the detection of A. marginale infection were found to be 65.2% (95% CI, 5

90 Development of A. marginale in cell culture was morphologically similar

91 Our results demonstrate a diversity of A. marginale subsp. centrale strains from cattle and wil

92 One-dimensional gel electrophoresis of A. marginale proteins demonstrated size polymorphism of

93 es which we hypothesize reflect emergence of A. marginale antigenic variants.

94 as been less interest in the epidemiology of A. marginale subsp. centrale, and, as a result, there ar

95 cells contributes to the rapid exhaustion of A. marginale-specific T cells following infection and th

96 immunized with the protective OM fraction of A. marginale.

97 1a, which encodes the complete msp1a gene of A. marginale under the control of human cytomegalovirus

98 ginale was evaluated by using immunoblots of A. marginale proteins separated by one- and two-dimensio

99 P1a as that found on the Virginia isolate of A. marginale in bovine erythrocytes and tick salivary gl

100 Recently, the Virginia isolate of A. marginale was propagated in a continuous tick cell li

101 Isolates of A. marginale from the southern United States (Florida, M

102 ine the genetic variations among isolates of A. marginale obtained during 2001 from infected cattle f

103 Many geographic isolates of A. marginale occur in the United States and have been id

104 tic heterogeneity observed among isolates of A. marginale within Oklahoma could be explained by cattl

105 not conserved between different isolates of A. marginale, and at least in the isolate from Florida,

106 h MSP2 antigenic variation as a mechanism of A. marginale persistence.

107 g the msp1aS gene, a homolog of msp1alpha of A. marginale, which contains repeats at the 5' ends that

108 ophilum, MSP2(P44), is homologous to MSP2 of A. marginale, has a similar organization of conserved an

109 ion-feeding ticks, and whether the number of A. marginale organisms per salivary gland is significant

110 sence of physiologically relevant numbers of A. marginale organisms.

111 PCR results indicated high occurrence of A. marginale subsp. centrale infections, ranging from 25

112 quence variants did not change on passage of A. marginale between culture, acute erythrocyte stage in

113 evasion that allows long-term persistence of A. marginale in the mammalian reservoir.

114 ombination, selection for sub-populations of A. marginale in the vertebrate host and/or PCR errors.

115 uence variants in bloodstream populations of A. marginale.

116 ere that the major outer membrane protein of A. marginale, MSP2, is encoded on a polycistronic mRNA.

117 discovered that several surface proteins of A. marginale encode polymorphic multigene families.

118 two most immunodominant surface proteins of A. marginale followed by emergence of unique variants in

119 ple genes encoding major surface proteins of A. marginale.

120 vary important antigenic surface proteins of A. marginale.

121 are also homologous to the MSP-2 proteins of A. marginale; thus, they were designated GE MSP-2A (45 k

122 In contrast, the surface proteome of A. marginale isolated from tick cells was much less comp

123 show that the single hypervariable region of A. marginale MSP2 encodes epitopes that are immunogenic

124 esized and used to amplify msp1 sequences of A. marginale from tick cell cultures, from cattle during

125 erythrocytic stage, currently the source of A. marginale antigen, was determined.

126 spectrometry and tandem mass spectrometry of A. marginale proteins identified with an appendage-speci

127 nic mRNA transcript in erythrocyte stages of A. marginale and defined the structure of the genomic ex

128 ame expression site is utilized in stages of A. marginale infecting tick salivary glands.

129 of nine pseudogenes from a single strain of A. marginale provides for a combinatorial number of poss

130 ith outer membranes of the Florida strain of A. marginale resulted in protective immunity that correl

131 The South Idaho strain of A. marginale was used, as MSP2 expression is restricted

132 is persistently infected with one strain of A. marginale, infection with a second strain (superinfec

133 Maries strain of A. marginale, we show that this surface coat is dominate

134 g a 90-kb region of the St. Maries strain of A. marginale.

135 ed and transmitted the Puerto Rico strain of A. marginale.

136 Maries (Idaho) strain of A. marginale.

137 icks infected with the South Idaho strain of A. marginale.

138 genes encoding MSP1b in a Florida strain of A. marginale.

139 ied outer membranes of the Florida strain of A. marginale.

140 Maries strain of A. marginale; the correct identification was confirmed b

141 mals superinfected with different strains of A. marginale and hypothesized that the msp2 pseudogene r

142 ion of epitopes common to several strains of A. marginale and the related pathogen A. ovis.

143 pitopes conserved among different strains of A. marginale for inclusion in a nucleic acid or recombin

144 m animals infected with different strains of A. marginale reacted with different 86-kDa antigens.

145 2 functional pseudogenes from two strains of A. marginale were detected and extracted from the phi29-

146 Five strains of A. marginale were selected in order to identify and comp

147 ction does not apply to two other strains of A. marginale, and that different variants are also expre

148 cally and phenotypically distinct strains of A. marginale.

149 strain (Florida) and heterologous strains of A. marginale.

150 ined antigens are conserved among strains of A. marginale.

151 ognized all bovine blood-passaged strains of A. marginale.

152 Testing of A. marginale-positive samples from tropical regions wher

153 hic region bound a unique MSP-2 expressed on A. marginale that was not recognized by antibody generat

154 n limit is the minimum infective unit of one A. marginale bacterium.

155 helper (Th) cell response to these and other A. marginale antigens and to determine conservation of T

156 ut the msp2 mRNA and MSP2 protein levels per A. marginale organism increase only minimally and transi

157 number of variants required for persistence, A. marginale uses segmental gene conversion, in which ol

158 Persistent A. marginale infection is characterized by repetitive ri

159 of rickettsemia that characterize persistent A. marginale infection and control of each rickettsemic

160 rotein antigenic variation during persistent A. marginale rickettsemia, were identified in the A. ovi

161 rge during cyclic rickettsemia in persistent A. marginale infection and suggest that emergent variant

162 d insignificant during subsequent persistent A. marginale infection up to 1 year.

163 In contrast, the same A. marginale strains expressed only OpAG2 in two differe

164 reater percentage of infected ticks secreted A. marginale into the saliva and did so at a significant

165 Under immune selection, A. marginale expresses complex major surface protein 2 m

166 (70 of 75) were infected with only a single A. marginale strain, five animals each carried two strai

167 tudy, we tested the hypothesis that specific A. marginale strains are preferentially transmitted.

168 ese data show that MSPs of erythrocyte-stage A. marginale are present on culture stages and may be st

169 s genomic expression site in Oklahoma strain A. marginale transmitted from in vitro cultures to cattl

170 mpared it to those of virulent senso stricto A. marginale strains.

171 athogens that generate actin filament tails, A. marginale infects mature erythrocytes, and the F-acti

172 Here, we demonstrate that A. marginale outer membrane protein A (AmOmpA; AM854) co

173 The results support the hypothesis that A. marginale gene expression is regulated by the specifi

174 The A. marginale msp3 gene msp3-12 was cloned and expressed

175 strain (low transmission efficiency) and the A. marginale St. Maries strain (high transmission effici

176 antigenic proteins, 14 are annotated in the A. marginale genome and include type IV secretion system

177 which tick cell gene expression mediates the A. marginale developmental cycle and trafficking through

178 Recently, complete sequencing of the A. marginale genome has identified an expanded set of ge

179 A database search of the A. marginale genome identified 24 antigenic proteins tha

180 Recent sequencing and annotation of the A. marginale genome predicts at least 62 outer membrane

181 Using the A. marginale genome sequence to track the origin of sequ

182 Interestingly, the 5' structure of this A. marginale msp2 locus is conserved in the omp1 gene lo

183 All three A. marginale Anks were confirmed to be expressed during

184 pies were identified in the genomes of three A. marginale strains.

185 ecific CD4+ T-cell clones responded to three A. marginale strains, confirming the VirB9-specific T-ce

186 lso proliferated specifically in response to A. marginale and produced high titers of gamma interfero

187 ticks and/or IDE8 tick cells in response to A. marginale infection.

188 -12 would augment type 1 recall responses to A. marginale.

189 These data suggest that, similarly to A. marginale, A. phagocytophilum uses combinatorial mech

190 This restriction of transmitted A. marginale variant types, in contrast to the marked di

191 We have identified two A. marginale strains with significant differences in the

192 host, we tested whether the presence of two A. marginale (sensu lato) strains that differed in trans

193 gainst high-level bacteremia and anemia upon A. marginale challenge of cattle and effectively recapit

194 proportion of erythrocytes containing viable A. marginale in vitro, indicating that an antibody-indep

195 variants revealed a change in structure when A. marginale was transferred from one cell-type to anoth

196 ted cattle from east-central Oklahoma, where A. marginale is endemic.

197 nfected reservoir herd within a region where A. marginale is endemic.

198 positive samples from tropical regions where A. marginale infection is endemic identified individual

199 n the cell-type (tick or mammalian) in which A. marginale developed.

200 liferated strongly in response to both whole A. marginale homogenates and purified outer membranes, a

201 n the United States would be associated with A. marginale transmission.

202 Thus, infection of cattle with A. marginale leads to the rapid loss of Ag-specific T ce

203 n against severe disease upon challenge with A. marginale sensu stricto strains.

204 st cases, it is reported as coinfection with A. marginale without characterization of the strain.

205 ific CD4(+) T cells in cattle immunized with A. marginale outer membrane proteins or purified outer m

206 centor variabilis persistently infected with A. marginale after feeding successively on one susceptib

207 es of cultured IDE8 tick cells infected with A. marginale.

208 gainst erythrocyte stages, also reacted with A. marginale from cell culture and tick salivary glands.

209 marginale strains, as has been reported with A. marginale and A. marginale subsp. centrale strains.

210 zed calves following recall stimulation with A. marginale.