scholarly journals pMGA Phenotypic Variation in Mycoplasma gallisepticumOccurs In Vivo and Is Mediated by Trinucleotide Repeat Length Variation

2000 ◽  
Vol 68 (10) ◽  
pp. 6027-6033 ◽  
Author(s):  
M. D. Glew ◽  
Glenn F. Browning ◽  
Philip F. Markham ◽  
Ian D. Walker
Keyword(s):  
Trinucleotide Repeat ◽  
Ex Vivo ◽  
Adaptive Immune Response ◽  
Surface Protein ◽  
Length Variation ◽  
Major Surface Protein ◽  
Adaptive Immune ◽  
Major Surface ◽  
Successful Colonization

ABSTRACT Chickens were infected with a pathogenic strain of Mycoplasma gallisepticum, and the expression of pMGA, the major surface protein, was inferred by examination of colonies from ex vivo cells. Within 2 days postinfection, 40% of cells had ceased the expression of the original pMGA surface protein (pMGA1.1), and by day 6, the majority of recovered cells were in this category. The switch in pMGA phenotype which had occurred in vivo was reversible, since most colonies produced from ex vivo progenitors exhibited frequent pMGA1.1+sectors. After prolonged in vivo habitation, increasing proportions of recovered cells gave rise to variant pMGA colonies which had switched from the expression of pMGA1.1 to another gene, pMGA1.2, concomitant with the acquisition of a (GAA)12 motif 5′ to its promoter. Collectively, the results suggest that changes in M. gallisepticum pMGA gene expression in vivo are normal, common, and possibly obligate events for successful colonization of the host. Surprisingly, the initial cessation of pMGA1.1 expression occurred in the absence of detectable pMGA antibodies and seemed to precede the adaptive immune response.

scholarly journals Expression of Anaplasma marginale Major Surface Protein 2 Variants during Persistent Cyclic Rickettsemia

1998 ◽  
Vol 66 (3) ◽  
pp. 1200-1207 ◽  
Author(s):  
Dorothy M. French ◽  
Terry F. McElwain ◽  
Travis C. McGuire ◽  
Guy H. Palmer
Keyword(s):  
Genetic Variants ◽  
Protective Immunity ◽  
Genetic Variant ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
Competitive Pcr ◽  
Cloning And Sequencing ◽  
Major Surface Protein ◽  
Major Surface

ABSTRACT Anaplasma marginale is an intraerythrocytic rickettsial pathogen of cattle in which infection persists for the life of the animal. Persistent A. marginale infection is characterized by repetitive rickettsemic cycles which we hypothesize reflect emergence of A. marginale antigenic variants. In this study, we determined whether variants of major surface protein 2 (MSP-2), a target of protective immunity encoded by a polymorphic multigene family, arise during persistent rickettsemia. By using a quantitative competitive PCR to identify rickettsemic cycles,msp-2 transcripts expressed in vivo were isolated from peak rickettsemia of sequential cycles. Cloning and sequencing ofmsp-2 cDNA revealed that genetic variants of MSP-2 emerge representing a minimum of four genetic variant types in each cycle during persistent infection. Two-color immunofluorescence using variant-specific antibody showed that emergence of MSP-2 variants resulted in expression of a minimum of three antigenic types of MSP-2 within one rickettsemic cycle. Therefore immune control of each cycle would require responses to an antigenically diverse A. marginale population. These findings demonstrate that polymorphic MSP-2 variants emerge during cyclic rickettsemia in persistent A. marginale infection and suggest that emergent variants play an important role in persistence.

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.

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.

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