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 Interleukin-12 as an Adjuvant Promotes Immunoglobulin G and Type 1 Cytokine Recall Responses to Major Surface Protein 2 of the Ehrlichial Pathogen Anaplasma marginale

2000 ◽  
Vol 68 (1) ◽  
pp. 270-280 ◽  
Author(s):  
Wenbin Tuo ◽  
Guy H. Palmer ◽  
Travis C. McGuire ◽  
Daming Zhu ◽  
Wendy C. Brown
Keyword(s):  
Protective Immunity ◽  
Mononuclear Cells ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
Interleukin 12 ◽  
Major Surface Protein ◽  
Ifn Γ ◽  
Major Surface ◽  
Type 1 Cytokine

ABSTRACT Anaplasma marginale is a tick-transmitted pathogen of cattle closely related to the human ehrlichiae, Ehrlichia chaffeensis and the agent of human granulocytic ehrlichiosis (HGE). These pathogens have in common a structurally conserved outer membrane protein (OMP) designated the major surface protein 2 (MSP-2) in A. marginale and HGE and OMP-1 in E. chaffeensis. Protective immunity against ehrlichial pathogens is believed to require induction of gamma interferon (IFN-γ) and opsonizing immunoglobulin (Ig) subclasses directed against OMP epitopes that, in concert, activate macrophages for phagocytosis and killing. Because interleukin-12 (IL-12) acts as an adjuvant for protein immunization to induce IFN-γ and protective immunity against intracellular pathogens, we hypothesized that as an adjuvant with MSP-2, IL-12 would augment type 1 recall responses to A. marginale. IL-12 was coadsorbed with MSP-2 to alum and shown to significantly enhance IFN-γ production by lymph node cells (LNC) and LNC-derived CD4+ T-cell lines from immunized calves following recall stimulation with A. marginale. LNC proliferation and IL-2 production were also enhanced in IL-12-treated calves. Elevated recall proliferative responses by peripheral blood mononuclear cells were still evident 9 months after immunization. Serum IgG levels were consistently increased in IL-12 immunized calves, predominantly due to higher IgG1 responses. The results support the use of IL-12 coadsorbed with OMP of ehrlichial pathogens in alum to amplify both antibody and type-1 cytokine responses important for protective immunity.

scholarly journals CD4+ T Lymphocytes from Anaplasma marginale Major Surface Protein 2 (MSP2) Vaccinees Recognize Naturally Processed Epitopes Conserved in MSP3

2004 ◽  
Vol 72 (6) ◽  
pp. 3688-3692 ◽  
Author(s):  
Wendy C. Brown ◽  
Guy H. Palmer ◽  
Kelly A. Brayton ◽  
Patrick F. M. Meeus ◽  
Anthony F. Barbet ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
T Lymphocyte ◽  
Antigenic Variation ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
Lymphocyte Response ◽  
Major Surface Protein ◽  
C Terminus ◽  
N Terminus ◽  
Major Surface

ABSTRACT Major surface protein 2 (MSP2) and MSP3 of the persistent bovine ehrlichial pathogen Anaplasma marginale are immunodominant proteins that undergo antigenic variation. The recently completed sequence of MSP3 revealed blocks of amino acids in the N and C termini that are conserved with MSP2. This study tested the hypothesis that CD4+ T cells specific for MSP2 recognize naturally processed epitopes conserved in MSP3. At least one epitope in the N terminus and two in the C terminus of MSP2 were also processed from MSP3 and presented to CD4+ T lymphocytes from MSP2-immunized cattle. This T-lymphocyte response to conserved and partially conserved epitopes may contribute to the immunodominance of MSP2 and MSP3.

scholarly journals Major Histocompatibility Complex Class II DR-Restricted Memory CD4+ T Lymphocytes Recognize Conserved Immunodominant Epitopes of Anaplasma marginale Major Surface Protein 1a

2002 ◽  
Vol 70 (10) ◽  
pp. 5521-5532 ◽  
Author(s):  
Wendy C. Brown ◽  
Travis C. McGuire ◽  
Waithaka Mwangi ◽  
Kimberly A. Kegerreis ◽  
Henriette Macmillan ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Protective Immunity ◽  
Surface Protein ◽  
T Cell Epitopes ◽  
Major Surface Protein ◽  
Histocompatibility Complex ◽  
Cell Clones ◽  
Major Surface

ABSTRACT Native major surface protein 1 (MSP1) of Anaplasma marginale, composed of covalently associated MSP1a and MSP1b proteins, stimulates protective immunity in cattle against homologous and heterologous strain challenge. Protective immunity against pathogens in the family Anaplasmataceae involves both CD4+ T cells and neutralizing immunoglobulin G. Thus, an effective vaccine should contain both CD4+ T- and B-lymphocyte epitopes that will elicit strong memory responses upon infection with homologous and heterologous strains. Previous studies demonstrated that the predominant CD4+ T-cell response in MSP1 vaccinates is directed against the MSP1a subunit. The present study was designed to identify conserved CD4+ T-cell epitopes in MSP1a presented by a broadly represented subset of major histocompatibility complex (MHC) class II molecules that would be suitable for inclusion in a recombinant vaccine. Transmembrane protein prediction analysis of MSP1a from the Virginia strain revealed a large hydrophilic domain (HD), extending from amino acids (aa) 1 to 366, and a hydrophobic region extending from aa 367 to 593. The N terminus (aa 1 to 67) includes one 28-aa form A repeat and one 29-aa form B repeat, which each contain an antibody neutralization-sensitive epitope [Q(E)ASTSS]. In MSP1 vaccinates, recombinant MSP1a HD (aa 1 to 366) stimulated recall proliferative responses that were comparable to those against whole MSP1a excluding the repeat region (aa 68 to 593). Peptide mapping determined a minimum of five conserved epitopes in aa 151 to 359 that stimulated CD4+ T cells from cattle expressing DR-DQ haplotypes common in Holstein-Friesian breeds. Peptides representing three epitopes (aa 231 to 266, aa 270 to 279, and aa 290 to 319) were stimulatory for CD4+ T-cell clones and restricted by DR. A DQ-restricted CD4+ T-cell epitope, present in the N-terminal form B repeat (VSSQSDQASTSSQLG), was also mapped using T-cell clones from one vaccinate. Although form B repeat-specific T cells did not recognize the form A repeat peptide (VSSQS_EASTSSQLG), induction of T-cell anergy by this peptide was ruled out. The presence of multiple CD4+ T-cell epitopes in the MSP1a HD, in addition to the neutralization-sensitive epitope, supports the testing of this immunogen for induction of protective immunity against A. marginale challenge.

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.

scholarly journals The immunization-induced antibody response to the Anaplasma marginale major surface protein 2 and its association with protective immunity

Vaccine ◽  
2010 ◽  
Vol 28 (21) ◽  
pp. 3741-3747 ◽  
Author(s):  
Susan M. Noh ◽  
Yan Zhuang ◽  
James E. Futse ◽  
Wendy C. Brown ◽  
Kelly A. Brayton ◽  
...  
Keyword(s):  
Antibody Response ◽  
Protective Immunity ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
Major Surface Protein ◽  
Major Surface

scholarly journals Surviving older patients show preserved cellular and humoral immunological memory several months after SARS-CoV-2 infection

2021 ◽  
Author(s):  
Alejandra García-Torre ◽  
Eva Bueno-García ◽  
Rocío López-Martínez ◽  
Beatriz Rioseras ◽  
Marco Antonio Moro-García ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Immune Responses ◽  
B Lymphocyte ◽  
Immunological Memory ◽  
Specific Memory ◽  
Great Heterogeneity ◽  
Ifn Γ ◽  
Humoral Responses ◽  
Lymphocyte Responses ◽  
Memory T Lymphocytes

Abstract Understanding how older people respond to SARS-CoV-2 is critical if we are to confront the COVID-19 pandemic and establish effective vaccination strategies. Immunosenescence reduces the ability to respond to neoantigens and may compromise the life of infected individuals. Here, we analysed the immunological memory to SARS-CoV-2 in 102 recovered patients aged over 60 years several months after the infection had been resolved. Specific memory T lymphocytes against the virus were measured by IFN-γ and granzyme B release by ELISpot; memory B lymphocyte responses were quantified by detection of anti-S IgG1 producer cells by ELISpot and anti-S and anti-N antibodies were determined by ELISA. Memory T lymphocytes were found in peripheral blood of most of the studied donors, more than seven months after the infection in some of them. Fewer patients maintained memory B lymphocytes, but antibodies, mainly anti-S, were highly durable and positively correlated with T responses. More robust humoral responses were found in patients who had more severe symptoms and had been admitted to hospital. We concluded that specific immunity against SARS-CoV-2 is effectively preserved regardless of age, despite the great heterogeneity of their immune responses, and that memory T lymphocytes and anti-S IgG might be more durable than memory B cells and anti-N IgG.

scholarly journals The Repertoire of Anaplasma marginale Antigens Recognized by CD4+ T-Lymphocyte Clones from Protectively Immunized Cattle Is Diverse and Includes Major Surface Protein 2 (MSP-2) and MSP-3

1998 ◽  
Vol 66 (11) ◽  
pp. 5414-5422 ◽  
Author(s):  
Wendy C. Brown ◽  
Daming Zhu ◽  
Varda Shkap ◽  
Travis C. McGuire ◽  
Edmour F. Blouin ◽  
...  
Keyword(s):  
T Lymphocyte ◽  
Surface Protein ◽  
Anaplasma Marginale ◽  
Surface Proteins ◽  
Interleukin 4 ◽  
Protein Vaccine ◽  
Major Surface Protein ◽  
Th Cell ◽  
Cell Clones ◽  
Major Surface

ABSTRACT Major surface proteins of Anaplasma marginale are vaccine candidates. We recently demonstrated that immunization of calves with outer membranes of the Florida strain ofA. marginale resulted in protective immunity that correlated with a memory CD4+ T-lymphocyte response specific for major surface protein 1 (MSP-1), MSP-2, and MSP-3 (W. C. Brown, V. Shkap, D. Zhu, T. C. McGuire, W. Tuo, T. F. McElwain, and G. H. Palmer, Infect. Immun. 66:5406–5413, 1998). As immunogens, these proteins have been shown to induce complete or partial protection against homologous challenge. To further define the T helper (Th) cell response to these and other A. marginale antigens and to determine conservation of Th cell epitopes among genetically distinct A. marginalestrains, Th cell clones obtained prior to challenge from three immunized calves were characterized for antigen-specific responses. Nine distinct antigenic profiles were defined by 11 Th cell clones derived by stimulation with the Florida strain. Several clones responded to MSP-2, MSP-3, or both. All of these MSP-2- or MSP-3-specific clones and the majority of other clones that did not respond to MSPs recognized all bovine blood-passaged strains ofA. marginale. These results demonstrate conservation of certain Th cell epitopes between MSP-2 and MSP-3 and show that Th cell epitopes in MSP-2, MSP-3, and undefined antigens are conserved among strains of A. marginale. Of seven clones that responded to the blood-passaged Virginia strain, two did not recognize antigen prepared from this strain cultured in tick cells, suggesting differences in the antigenic composition between these stages. Analysis of the cytokines expressed by the Th cells revealed that all clones expressed gamma interferon and tumor necrosis factor alpha, and most coexpressed interleukin-4. Our results provide a rationale for identifying Th cell epitopes conserved among different strains of A. marginale for inclusion in a nucleic acid or recombinant protein vaccine.

Sign in / Sign up

Export Citation Format

Share Document