Presence of parasite antigen on the surface of P388D1 cells infected with Ehrlichia risticii

Messick, Joanne B.; Rikihisa, Yasuko

doi:10.1128/iai.60.8.3079-3086.1992

Cited by 14 publications

(8 citation statements)

References 26 publications

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“…Saponin treatment permeabilized not only host membranes but also ehrlichial membranes, resulting in immunolabeling of the interior of ehrlichiae as well. In contrast, in paraformaldehyde fixation given prior to immunostaining for the binding study, the antibody could not penetrate the ehrlichial membrane, resulting in ringlike immunolabeling (8). By 96 h the progression of the intracellular proliferation of E. risticii was demonstrable (Fig.…”

Section: Resultsmentioning

confidence: 97%

Characterization of Ehrlichia risticii binding, internalization, and proliferation in host cells by flow cytometry

Messick¹,

Rikihisa²

1993

Infect Immun

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The binding, internalization, and proliferation of Ehrlichia ristcii in P388D1 cells and equine polymorphonuclear (PMN) leukocytes were studied by immunofluorescent staining and flow cytometric analysis. The binding of ehrlichiae to P388D1 cells at 4°C was dose dependent, and the antigens of bound organisms were susceptible to pronase treatment. Additionally, the binding of ehrlichiae to P388D1 cells was diminished when either P388D1 cells or ehrlichiae were treated with 1% paraformaldehyde for 30 min or 0.25% trypsin for 15 min. These results indicate that the ehrlichial ligand and host cell receptor are likely surface proteins. Following incubation at 37rC, bound E. risticii and/or its antigens were removed with pronase and indirect immunofluorescent staining in the presence of saponin was used to examine intracellular ehrlichiae. Our results indicate that E. rislicii was internalized into P388D1 cells within 3 h and proliferated by 48 h of incubation. The microfilament-disrupting agent cytochalasin D and the transglutaminase inhibitor monodansylcadaverine were used to differentiate between phagocytosis (sensitive to cytochalasin) and receptor-mediated endocytosis (sensitive to monodansylcadaverine) of E. risticii by P388D1 cells. In concentrations that produced distinctive morphological changes and inhibited phagocytosis of polystyrene latex beads, cytochalasin D did not suppress the infectivity of E. risticii. Binding, internalization, or proliferation of E. risticii was not affected by cytochalasin D. However, monodansylcadaverine inhibited infection ofE. risticii in a dose-dependent manner. The agent did not affect the attachment of ehrlichiae to host cells, but it did suppress internalization and proliferation. These results suggest that E. risticii is internalized by receptor-mediated endocytosis and that productive infection by E. risticii does not depend on phagocytosis by the P388D1 cells. Although E. risticii did not bind to the surface of equine PMN leukocytes at 4°C, organisms were taken up by this cell at 37°C. E. risticii, however, failed to survive in equine PMN leukocytes.

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Section: Resultsmentioning

confidence: 97%

Characterization of Ehrlichia risticii binding, internalization, and proliferation in host cells by flow cytometry

Messick¹,

Rikihisa²

1993

Infect Immun

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“…Results are the means Ϯ standard deviations of three independent experiments. significant role in host immune defense in infectious diseases as well as in ehrlichial infection through antibody-dependent cell-mediated cytotoxicity (27) and in vitro neutralization of infection (28,35). The role of antibody in proinflammatory cytokine induction in infectious diseases has, however, been overlooked because in most infections, the agent (virus, bacterium, or protozoan) itself causes a significant cytokine production.…”

Section: Discussionmentioning

confidence: 99%

Anti-Ehrlichia chaffeensis antibody complexed with E. chaffeensis induces potent proinflammatory cytokine mRNA expression in human monocytes through sustained reduction of IkappaB-alpha and activation of NF-kappaB

Lee

Rikihisa

1997

Infect Immun

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Ehrlichia chaffeensis is an obligatory intracellular bacterium that infects monocytes and macrophages and is the etiologic agent of human ehrlichiosis in the United States. Our previous studies showed that the exposure of human monocytes to E. chaffeensis induces the expression of interleukin-1␤ (IL-1␤), IL-8, and IL-10 genes in vitro but not the expression of tumor necrosis factor alpha (TNF-␣) and IL-6 mRNAs. In this study, the effect of anti-E. chaffeensis antibody complexed with E. chaffeensis on the expression of major proinflammatory cytokines in human monocytes was examined. Human monocytic cell line THP-1 was treated with E. chaffeensis which had been preincubated with human anti-E. chaffeensis serum for 2 h, and the levels of cytokine mRNAs were evaluated by competitive reverse transcription-PCR. Anti-E. chaffeensis antibody complexed with E. chaffeensis significantly enhanced mRNA expression of IL-1␤ in THP-1 cells. The expression of TNF-␣ and IL-6 mRNAs was also induced. The levels of secreted IL-1␤, TNF-␣, and IL-6 during 24 h of stimulation were comparable to those induced by Escherichia coli lipopolysaccharide at 1 g/ml. Fab fragment of anti-E. chaffeensis immunoglobulin G complexed with E. chaffeensis did not induce any of these three cytokines, indicating that ehrlichial binding is required for IL-1␤ mRNA expression and that binding of the immune complex to the Fc␥ receptor is required for TNF-␣ and IL-6 mRNA expression and enhanced IL-1␤ mRNA expression. Furthermore, prolonged degradation of IB-␣ and activation of NF-B were demonstrated in THP-1 cells exposed to anti-E. chaffeensis serum and E. chaffeensis. This result implies that development of anti-E. chaffeensis antibody in patients can result in the production of major proinflammatory cytokines, which may play an important role in the pathophysiology of ehrlichiosis and immune responses to it.

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“…Antigenic changes on the infected cell surface have been well characterized in parasitic [3^5] and bacterial infections [6,7]. Few reports have demonstrated the induction of mycobacterial genes during infection [8,9] and an altered expression of various known adhesion and costimulatory molecules on infected cell surface [10,11].…”

Section: Introductionmentioning

confidence: 99%

Membrane surface of Mycobacterium microti-infected macrophages antigenically differs from that of uninfected macrophages

Majumdar

2000

FEMS Immunology and Medical Microbiology

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Identification of the antigenic changes in mycobacteria-infected macrophage may be important in understanding the mechanisms responsible for the intracellular survival of the bacteria. In the present study, Mycobacterium microti-infected macrophages were utilized to investigate the possibility of differentiating the infected cells from normal cells, based on the antigenic changes occurring in the membranes. Antisera were generated against bacterial extract, heat-killed bacteria and crude preparation of M. microti-infected homologous macrophage membrane. The reactivity of these antisera, towards in vitro infected macrophages, was compared by flow cytometry. Unlike anti-bacterial extract antiserum or anti-heat-killed bacterial antiserum, anti-infected macrophage membrane antiserum reacted with infected macrophage surface. This reactivity increased with the increase in post-infection time. However, it was not observed with uninfected macrophages, PMA- or lipopolysaccharide-activated macrophages and those harboring Mycobacterium tuberculosis H37Ra, heat-killed M. microti and Leishmania donovani. Interestingly, anti-infected macrophage membrane antiserum identified a 63-kDa antigen in M. microti-infected macrophage membranes which was not present in the membranes of normal macrophages, activated macrophages and of those infected with M. tuberculosis H37Ra, heat-killed M. microti and L. donovani. Thus, membranes of M. microti-infected macrophages differ antigenically from those of the normal macrophages and infected homologous macrophage membrane antiserum provides a useful tool in studying such changes.

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Presence of parasite antigen on the surface of P388D1 cells infected with Ehrlichia risticii

Cited by 14 publications

References 26 publications

Characterization of Ehrlichia risticii binding, internalization, and proliferation in host cells by flow cytometry

Characterization of Ehrlichia risticii binding, internalization, and proliferation in host cells by flow cytometry

Anti-Ehrlichia chaffeensis antibody complexed with E. chaffeensis induces potent proinflammatory cytokine mRNA expression in human monocytes through sustained reduction of IkappaB-alpha and activation of NF-kappaB

Membrane surface of Mycobacterium microti-infected macrophages antigenically differs from that of uninfected macrophages

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