Bifunctional CD4–DC-SIGN Fusion Proteins Demonstrate Enhanced Avidity to gp120 and Inhibit HIV-1 Infection and Dissemination

Du, Tao; Hu, Kai; Yang, Jun; Jin, Jing; Chang, Li; Stieh, Daniel J.; Griffin, George E.; Shattock, Robin J.; Hu, Qinxue

doi:10.1128/aac.00623-12

Cited by 22 publications

(23 citation statements)

References 56 publications

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“…Upregulation of DC-SIGN on M2a-MDM may compensate for low CD4 by facilitating binding and receptor/coreceptor-mediated virus entry) [28]. This interpretation is supported by a study [35] showing that gp120 Env binding to DC-SIGN enhances access to the CD4-binding site. Increased expression of DC-SIGN on M2a-MDM may also promote oligomerization of DC-SIGN, or changes in the configuration of CD4/CCR5/DC-SIGN complexes [28].…”

Section: Discussionmentioning

confidence: 86%

Dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin mediates HIV-1 infection of and transmission by M2a-polarized macrophages in vitro

Cassol

Cassetta

Rizzi³

et al. 2013

Aids

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Objective To assess in-vitro effects of monocyte-derived macrophage (MDM) polarization into M1 and M2a cells on HIV-1 replication and transmission and obtain new insights into the potential importance of macrophage polarization in vivo. Design Human peripheral blood monocytes were differentiated into MDM for 7 days. Control and MDM polarized into M1 or M2a cells were exposed to different strains of HIV-1 and assessed for their ability to bind and transmit virus to CD4+ T lymphocytes. Methods MDM were incubated with either tumour necrosis factor-alpha (TNF-α) along with interferon-gamma (IFN-γ) or with interleukin-4 (IL-4) for 18 h to obtain M1 or M2a cells, respectively. Expression of cell surface antigens, including CD4 and dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN), was evaluated by flow cytometry. C-C chemokine receptor type 5 (CCR5)-dependent (R5) HIV-1 binding, DNA synthesis and viral replication were assessed in the presence or absence of anti-DC-SIGN blocking mAbs. Transmission of C-X-C chemokine receptor type 4 (CXCR4)-dependent (X4) and R5 HIV-1 from MDM to IL-2 activated CD4+ T cells was also investigated. Results DC-SIGN was strongly upregulated on M2a-MDM and downregulated on M1-MDM compared with control MDM. DC-SIGN facilitated HIV-1 entry and DNA synthesis in M2a-MDM, compensating for their low levels of CD4 cell expression. M2a-MDM efficiently transmitted both R5 and X4 HIV-1 to CD4+ T cells in a DC-SIGN-dependent manner. Conclusion DC-SIGN facilitates HIV-1 infection of M2a-MDM, and HIV-1 transfer from M2a-MDM to CD4+ T cells. M2a-polarized tissue macrophages may play an important role in the capture and spread of HIV-1 in mucosal tissues and placenta.

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Section: Discussionmentioning

confidence: 86%

Dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin mediates HIV-1 infection of and transmission by M2a-polarized macrophages in vitro

Cassol

Cassetta

Rizzi³

et al. 2013

Aids

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“…Classically the term was applied only to antibodies and fragments of antibodies, Fab and F(ab )2, but later it has naturally been extended to single-domain antigen-binding recombinant fragments and natural nanobodies [32,33]. Likewise the definition can be expanded to cover similar activities by soluble forms of viral receptors [34,35], naturally occurring defensins, or other molecules of the innate immune system [36,37]; it can be extended to lectins, either derived from plants or soluble recombinant and hybrid forms of mannose C-type lectin receptors (MCLRs) [38]. With regard to small organic molecules, if they are said to be neutralizing, it should be clarified whether that is meant to imply that they act by binding to the surface of the virion [39][40][41][42][43][44][45][46][47][48][49].…”

Section: The Definition Of Virus Neutralizationmentioning

confidence: 99%

Neutralization of Virus Infectivity by Antibodies: Old Problems in New Perspectives

Klasse

2014

Advances in Biology

200

208

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Neutralizing antibodies (NAbs) can be both sufficient and necessary for protection against viral infections, although they sometimes act in concert with cellular immunity. Successful vaccines against viruses induce NAbs but vaccine candidates against some major viral pathogens, including HIV-1, have failed to induce potent and effective such responses. Theories of how antibodies neutralize virus infectivity have been formulated and experimentally tested since the 1930s; and controversies about the mechanistic and quantitative bases for neutralization have continually arisen. Soluble versions of native oligomeric viral proteins that mimic the functional targets of neutralizing antibodies now allow the measurement of the relevant affinities of NAbs. Thereby the neutralizing occupancies on virions can be estimated and related to the potency of the NAbs. Furthermore, the kinetics and stoichiometry of NAb binding can be compared with neutralizing efficacy. Recently, the fundamental discovery that the intracellular factor TRIM21 determines the degree of neutralization of adenovirus has provided new mechanistic and quantitative insights. Since TRIM21 resides in the cytoplasm, it would not affect the neutralization of enveloped viruses, but its range of activity against naked viruses will be important to uncover. These developments bring together the old problems of virus neutralization—mechanism, stoichiometry, kinetics, and efficacy—from surprising new angles.

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“…Prokaryotic expression and purification of gB pET-gB was expressed in an Escherichia coli system (Rosetta strain; Novagen) and purified as described previously with modifications (39). Briefly, bacteria bearing pET-gB were induced for 4 h with isopropylb-D-thiogalactoside, and gB proteins were harvested from the insoluble fraction of ultrasonic-treated bacteria by centrifugation (1200 3 g, 30 min at 4˚C).…”

Section: Mice Hsv-2 and Cell Linesmentioning

confidence: 99%

“…gB 1-G-10 mAb (1:1000 dilution; Santa Cruz, sc-52425) and H126 mAb (1:1000 dilution; Santa Cruz, sc-69799) followed by HRP-labeled donkey anti-sheep IgG (1:5000 dilution; Santa Cruz) were used for gB detection in SDS-PAGE and native PAGE, respectively. The colorimetric reaction was developed as described previously (16,39).…”

Section: Sds-page Native Page and Western Blottingmentioning

confidence: 99%

Immunization with HSV-2 gB-CCL19 Fusion Constructs Protects Mice against Lethal Vaginal Challenge

Yan

Deng

et al. 2015

The Journal of Immunology

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There is a lack of an HSV-2 vaccine, in part as the result of various factors that limit robust and long-term memory immune responses at the mucosal portals of viral entry. We previously demonstrated that chemokine CCL19 augmented mucosal and systemic immune responses to HIV-1 envelope glycoprotein. Whether such enhanced immunity can protect animals against virus infection remains to be addressed. We hypothesized that using CCL19 in a fusion form to direct an immunogen to responsive immunocytes might have an advantage over CCL19 being used in combination with an immunogen. We designed two fusion constructs, plasmid (p)gBIZCCL19 and pCCL19IZgB, by fusing CCL19 to the C- or N-terminal end of the extracellular HSV-2 glycoprotein B (gB) with a linker containing two (Gly4Ser)2 repeats and a GCN4-based isoleucine zipper motif for self-oligomerization. Following immunization in mice, pgBIZCCL19 and pCCL19IZgB induced strong gB-specific IgG and IgA in sera and vaginal fluids. The enhanced systemic and mucosal Abs showed increased neutralizing activity against HSV-2 in vitro. Measurement of gB-specific cytokines demonstrated that gB-CCL19 fusion constructs induced balanced Th1 and Th2 cellular immune responses. Moreover, mice vaccinated with fusion constructs were well protected from intravaginal lethal challenge with HSV-2. Compared with pgB and pCCL19 coimmunization, fusion constructs increased mucosal surface IgA+ cells, as well as CCL19-responsive immunocytes in spleen and mesenteric lymph nodes. Our findings indicate that enhanced humoral and cellular immune responses can be achieved by immunization with an immunogen fused to a chemokine, providing information for the design of vaccines against mucosal infection by HSV-2 and other sexually transmitted viruses.

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Bifunctional CD4–DC-SIGN Fusion Proteins Demonstrate Enhanced Avidity to gp120 and Inhibit HIV-1 Infection and Dissemination

Cited by 22 publications

References 56 publications

Dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin mediates HIV-1 infection of and transmission by M2a-polarized macrophages in vitro

Dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin mediates HIV-1 infection of and transmission by M2a-polarized macrophages in vitro

Neutralization of Virus Infectivity by Antibodies: Old Problems in New Perspectives

Immunization with HSV-2 gB-CCL19 Fusion Constructs Protects Mice against Lethal Vaginal Challenge

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