Evolution and function of tandem repeats in the major surface protein 1a of the ehrlichial pathogenAnaplasma marginale

2001 ◽  
Vol 2 (2) ◽  
pp. 163-174 ◽  
Author(s):  
José de la Fuente ◽  
Jose C. Garcia-Garcia ◽  
Edmour F. Blouin ◽  
Sergio D. Rodríguez ◽  
Migel A. García ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Control Strategies ◽  
Surface Protein ◽  
Single Copy ◽  
Major Surface Protein ◽  
Host Parasite Interactions ◽  
Major Surface ◽  
And Function ◽  
Host Parasite ◽  
Bovine Erythrocytes

AbstractThe major surface protein (MSP) 1a of the ehrlichial cattle pathogenAnaplasma marginale, encoded by the single-copy genemsp1α, has been shown to have a neutralization-sensitive epitope and to be an adhesin for bovine erythrocytes and tick cells.msp1αhas been found to be a stable genetic marker for the identification of geographic isolates ofA. marginalethroughout development in acutely and persistently infected cattle and in ticks. The molecular weight of MSP1a varies among geographic isolates ofA. marginalebecause of a varying number of tandemly repeated peptides of 28–29 amino acids. Variation in the sequence of the tandem repeats occurs within and among isolates, and may have resulted from evolutionary pressures exerted by ligand–receptor and host–parasite interactions. These repeated sequences include markers for tick transmissibility that may be important in the identification of ehrlichial pathogens because they may influence control strategies and the design of subunit vaccines.

scholarly journals Infection of Tick Cells and Bovine Erythrocytes with One Genotype of the Intracellular Ehrlichia Anaplasma marginale Excludes Infection with Other Genotypes

2002 ◽  
Vol 9 (3) ◽  
pp. 658-668 ◽  
Author(s):  
José de la Fuente ◽  
Jose C. Garcia-Garcia ◽  
Edmour F. Blouin ◽  
Jeremiah T. Saliki ◽  
Katherine M. Kocan
Keyword(s):  
United States ◽  
Tandem Repeats ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
The United States ◽  
The Other ◽  
Tick Cell ◽  
Anaplasma Ovis ◽  
Major Surface ◽  
Bovine Erythrocytes

ABSTRACT Anaplasma marginale, a tick-borne rickettsial pathogen of cattle, is endemic in several areas of the United States. Many geographic isolates of A. marginale that occur in the United States are characterized by the major surface protein 1a, which varies in sequence and molecular weight due to different numbers of tandem repeats of 28 or 29 amino acids. Recent studies (G. H. Palmer, F. R. Rurangirwa, and T. F. McElwain, J. Clin. Microbiol. 39:631-635, 2001) of an A. marginale-infected herd of cattle in an area of endemicity demonstrated that multiple msp1α genotypes were present but that only one genotype was found per individual bovine. These findings suggested that infection of cattle with other genotypes was excluded. The present study was undertaken to confirm the phenomenon of infection exclusion of A. marginale genotypes in infected bovine erythrocytes and cultured tick cells. Two tick-transmissible isolates of A. marginale, one from Virginia and one from Oklahoma, were used for these studies. In two separate trials, cattle inoculated with equal doses of the two isolates developed infection with only one genotype. Tick cell cultures inoculated with equal doses of the two isolates became infected with only the Virginia isolate of A. marginale. When cultures were inoculated with different ratios of the Oklahoma and Virginia isolates of A. marginale, the isolate inoculated in the higher ratio became established and excluded infection with the other. When cultures with established infections of one isolate were subsequently infected with the other, only the established isolate was detected. We documented infection exclusion during initial infection in cell culture by labeling each isolate with a different fluorescent dye. After 2 days in culture, only a single isolate was detected per cell by fluorescence microscopy. Finally, when Anaplasma ovis infections were established in cultures that were subsequently inoculated with the Virginia or Oklahoma isolate of A. marginale, A. marginale infection was excluded. These studies confirm that infection exclusion occurs with A. marginale in bovine erythrocytes and tick cells, resulting in the establishment of only one genotype, and appears to be the first report of infection exclusion for Anaplasma and Ehrlichia species.

scholarly journals Hide and seek: interplay between influenza viruses and B cells

2020 ◽  
Vol 32 (9) ◽  
pp. 605-611 ◽  
Author(s):  
Masayuki Kuraoka ◽  
Yu Adachi ◽  
Yoshimasa Takahashi
Keyword(s):  
B Cells ◽  
B Cell ◽  
Surface Protein ◽  
Influenza Viruses ◽  
Influenza Vaccines ◽  
Native Structure ◽  
Humoral Immune ◽  
Protective Antibodies ◽  
Major Surface ◽  
And Function

Abstract Influenza virus constantly acquires genetic mutations/reassortment in the major surface protein, hemagglutinin (HA), resulting in the generation of strains with antigenic variations. There are, however, HA epitopes that are conserved across influenza viruses and are targeted by broadly protective antibodies. A goal for the next-generation influenza vaccines is to stimulate B-cell responses against such conserved epitopes in order to provide broad protection against divergent influenza viruses. Broadly protective B cells, however, are not easily activated by HA antigens with native structure, because the virus has multiple strategies to escape from the humoral immune responses directed to the conserved epitopes. One such strategy is to hide the conserved epitopes from the B-cell surveillance by steric hindrance. Technical advancement in the analysis of the human B-cell antigen receptor (BCR) repertoire has dissected the BCRs to HA epitopes that are hidden in the native structure but are targeted by broadly protective antibodies. We describe here the characterization and function of broadly protective antibodies and strategies that enable B cells to seek these hidden epitopes, with potential implications for the development of universal influenza vaccines.

Three strains of Wolbachia pipientis and high rates of infection in Iranian sandfly species

2014 ◽  
Vol 104 (2) ◽  
pp. 195-202 ◽  
Author(s):  
A. Bordbar ◽  
S. Soleimani ◽  
F. Fardid ◽  
M.R. Zolfaghari ◽  
P. Parvizi
Keyword(s):  
Protein Gene ◽  
Surface Protein ◽  
Male And Female ◽  
Wolbachia Pipientis ◽  
Major Surface Protein ◽  
Zoonotic Cutaneous Leishmaniasis ◽  
Geographical Regions ◽  
Surface Protein Gene ◽  
Major Surface ◽  
Zoonotic Visceral Leishmaniasis

AbstractIndividual wild-caught sandflies from Iran were examined for infections of Wolbachia pipientis by targeting the major surface protein gene wsp of this intracellular α-proteobacterium. In total, 638 male and female sandflies were screened, of which 241 were found to be positive for one of three wsp haplotypes. Regardless of geographical origins and habitats, Phlebotomus (Phlebotomus) papatasi and other sandfly species were found to be infected with one common, widespread strain of A-group W. pipientis (Turk 54, GenBank accession EU780683; AY288297). In addition, a new A-group haplotype (Turk07, GenBank accession KC576916) was isolated from Phlebotomus (Paraphlebotomus) mongolensis and Phlebotomus (Pa.) caucasicus, and a new B-group haplotype (AZ2331, GenBank accession JX488735) was isolated from Phlebotomus (Larroussius) perfiliewi. Therefore, Wolbachia was found to occur in at least three of the incriminated vectors of zoonotic cutaneous leishmaniasis and zoonotic visceral leishmaniasis in different geographical regions of Iran. It may provide a new tool for the future control of leishmaniasis.

scholarly journals CD4+ T Lymphocytes from Calves Immunized withAnaplasma marginale Major Surface Protein 1 (MSP1), a Heteromeric Complex of MSP1a and MSP1b, Preferentially Recognize the MSP1a Carboxyl Terminus That Is Conserved among Strains

2001 ◽  
Vol 69 (11) ◽  
pp. 6853-6862 ◽  
Author(s):  
Wendy C. Brown ◽  
Guy H. Palmer ◽  
Harris A. Lewin ◽  
Travis C. McGuire
Keyword(s):  
T Lymphocytes ◽  
T Lymphocyte ◽  
Protective Immunity ◽  
B Lymphocyte ◽  
Surface Protein ◽  
Specific Response ◽  
Major Surface Protein ◽  
Ifn Γ ◽  
Major Surface ◽  
Lymphocyte Responses

ABSTRACT Native major surface protein 1 (MSP1) of the ehrlichial pathogenAnaplasma marginale induces protective immunity in calves challenged with homologous and heterologous strains. MSP1 is a heteromeric complex of a single MSP1a protein covalently associated with MSP1b polypeptides, of which at least two (designated MSP1F1 and MSP1F3) in the Florida strain are expressed. Immunization with recombinant MSP1a and MSP1b alone or in combination fails to provide protection. The protective immunity in calves immunized with native MSP1 is associated with the development of opsonizing and neutralizing antibodies, but CD4+ T-lymphocyte responses have not been evaluated. CD4+ T lymphocytes participate in protective immunity to ehrlichial pathogens through production of gamma interferon (IFN-γ), which promotes switching to high-affinity immunoglobulin G (IgG) and activation of phagocytic cells to produce nitric oxide. Thus, an effective vaccine for A. marginaleand related organisms should contain both T- and B-lymphocyte epitopes that induce a strong memory response that can be recalled upon challenge with homologous and heterologous strains. This study was designed to determine the relative contributions of MSP1a and MSP1b proteins, which contain both variant and conserved amino acid sequences, in stimulating memory CD4+ T-lymphocyte responses in calves immunized with native MSP1. Peripheral blood mononuclear cells and CD4+ T-cell lines from MSP1-immunized calves proliferated vigorously in response to the immunizing strain (Florida) and heterologous strains of A. marginale. The conserved MSP1-specific response was preferentially directed to the carboxyl-terminal region of MSP1a, which stimulated high levels of IFN-γ production by CD4+ T cells. In contrast, there was either weak or no recognition of MSP1b proteins. Paradoxically, all calves developed high titers of IgG antibodies to both MSP1a and MSP1b polypeptides. These findings suggest that in calves immunized with MSP1 heteromeric complex, MSP1a-specific T lymphocytes may provide help to MSP1b-specific B lymphocytes. The data provide a basis for determining whether selected MSP1a CD4+ T-lymphocyte epitopes and selected MSP1a and MSP1b B-lymphocyte epitopes presented on the same molecule can stimulate a protective immune response.

scholarly journals Anaplasma marginale Major Surface Protein 2 CD4+-T-Cell Epitopes Are Evenly Distributed in Conserved and Hypervariable Regions (HVR), Whereas Linear B-Cell Epitopes Are Predominantly Located in the HVR

2004 ◽  
Vol 72 (12) ◽  
pp. 7360-7366 ◽  
Author(s):  
Jeffrey R. Abbott ◽  
Guy H. Palmer ◽  
Chris J. Howard ◽  
Jayne C. Hope ◽  
Wendy C. Brown
Keyword(s):  
T Cell ◽  
B Cell ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
T Cell Epitopes ◽  
B Cell Epitopes ◽  
Major Surface Protein ◽  
Hypervariable Regions ◽  
Major Surface ◽  
Linear B

ABSTRACT Organisms in the genus Anaplasma express an immunodominant major surface protein 2 (MSP2), composed of a central hypervariable region (HVR) flanked by highly conserved regions. Throughout Anaplasma marginale infection, recombination results in the sequential appearance of novel MSP2 variants and subsequent control of rickettsemia by the immune response, leading to persistent infection. To determine whether immune evasion and selection for variant organisms is associated with a predominant response against HVR epitopes, T-cell and linear B-cell epitopes were localized by measuring peripheral blood gamma interferon-secreting cells, proliferation, and antibody binding to 27 overlapping peptides spanning MSP2 in 16 cattle. Similar numbers of MSP2-specific CD4+ T-cell epitopes eliciting responses of similar magnitude were found in conserved and hypervariable regions. T-cell epitope clusters recognized by the majority of animals were identified in the HVR (amino acids [aa] 171 to 229) and conserved regions (aa 101 to 170 and 272 to 361). In contrast, linear B-cell epitopes were concentrated in the HVR, residing within hydrophilic sequences. The pattern of recognition of epitope clusters by T cells and of HVR epitopes by B cells is consistent with the influence of protein structure on epitope recognition.

scholarly journals Microscopic And Molecular Identification of Anaplasma Ovis in Small Ruminants in Duhok Province in Kurdistan Region of Iraq

2020 ◽  
Vol 23 (2) ◽  
pp. 228-235
Author(s):  
Adnan Ahmed ◽  
Jassim M Abdo
Keyword(s):  
Microscopic Examination ◽  
Prevalence Rate ◽  
Small Ruminants ◽  
Surface Protein ◽  
Positive Sample ◽  
Pcr Analysis ◽  
Anaplasma Ovis ◽  
Blood Samples ◽  
Major Surface Protein ◽  
Major Surface

In last ten years, there has been a developing enthusiasm for microscopic organisms from the genus Anaplasma, particularly the species A. ovis. It is associated with the pathogenic action of these microscopic organisms in livestock. Anaplasma ovis is a tick-borne obligate intracellular rickettsial bacterium that causes anaplasmosis in domestic and wild small ruminants. The samples of the present study were collected from small ruminants from inside seven distinct regions (Akre, Simele, Zummar, Feshchapoor, Deraboon, Bajed Kandal,Karoda)of Duhok province, 389 (goats 75 and sheep 314) during the period of April and May 2018, blood sample were taken and thin smear was formed, after Giemsa’s staining the slide is observed under microscope. In this study used Giemsa stain for microscopic examination out of 389 animals 250 were found positive for Anaplasma ovis infection with a prevalence rate of 64.26 % and 139 of them were negative with a prevalence rate of 35.73 %. According to the species of animals, the highest prevalence of A. ovis infection in animals by using microscopic examination was 67.83 %, 213 positive sample from total 314 blood samples from sheep and lowest prevalence was 49.33 %, 37 positive sample from total 75 blood samples from goats. PCR analysis of 100 blood samples obtained from total 250 positive blood samples after DNA extraction and measure of concentration and purity we used 2 primers that target major surface protein 4 (MSP4) in A. ovis genomic DNA. The results of PCR test with major surface protein 4 primer was 83 samples positive from total 100 samples, According to the species of animals, the highest prevalence of A. ovis was 83.7 %, 72 positive sample from total 86 blood samples from sheep and lowest prevalence was 78.5 %, 11 positive sample from total 14 blood samples from goats.

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