Identification, Characterization, and Epitope Mapping of Human Monoclonal Antibody J19 That Specifically Recognizes Activated Integrin α4β7

Qi, Junpeng; Zhang, Kun; Zhang, Qiao; Sun, Yi; Fu, Ting; Li, Guohui; Chen, Jianfeng

doi:10.1074/jbc.m112.341263

Cited by 9 publications

(14 citation statements)

References 48 publications

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“…3C). The conformational change in a 4 b 7 upon activation by chemokine and Mn 2+ could be well reported by J19 binding (Qi et al, 2012). Consistent with the FRET results, both WT a 4 b 7 and a 4 CC/b 7 CC mutant transfectants were stained with J19 only after stimulation with 0.5 mM Mn 2+ but not in 1 mM Ca .…”

Section: Resultssupporting

confidence: 84%

“…To further study the binding characteristics of WT a 4 b 7 and a 4 CC/b 7 CC mutant to MAdCAM-1, we purified soluble a 4 b 7 proteins that contain the full-length ectodomain as described previously (Qi et al, 2012;Zhu et al, 2008) and measured the binding of WT a 4 b 7 and a 4 CC/b 7 CC proteins to MAdCAM-1 using surface plasmon resonance. In the presence of 1 mM Ca 2+ / Mg 2+ , soluble integrins bound to immobilized MAdCAM-1 in a concentration-dependent manner (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…3B), suggesting full extension of a 4 b 7 ectodomain. To further confirm that breaking the two disulfide bonds does not induce the typical conformational change in integrin a 4 b 7 on the cell surface, we examined the epitope expression of J19, a monoclonal antibody (mAb) that recognizes an epitope located in the a 4 b 7 head domain and only expressed in the extended a 4 b 7 (Qi et al, 2012) (Fig. 3C).…”

Section: Resultsmentioning

confidence: 99%

“…mAb against FAK and pY397-FAK were from Upstate Biotechnology. mAb J19 human IgG was prepared as described (Qi et al, 2012). mAb FIB504 against human b 7 was prepared from hybridoma (Developmental Studies Hybridoma Bank).…”

Section: Structural Model Constructionmentioning

confidence: 99%

“…The full-length a 4 b 7 ectodomain, consisting of b-propeller, thigh, knee, calf-1, calf-2 domains in a 4 subunit and bI domain, hybrid, PSI, I-EGF1-4, b-Tail domains in b 7 subunit, was purified as previously described (Qi et al, 2012;Yu et al, 2012;Zhu et al, 2008).…”

Section: Protein Purificationmentioning

confidence: 99%

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Disruption of disulfide-restriction at integrin knees induces activation and ligand-independent signaling of α4β7

Zhang

Pan

et al. 2013

Journal of Cell Science

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SummaryControl of integrin activation and signaling plays crucial roles in cell adhesion, spreading and migration. Here, we report that selective breakage of two conserved disulfide bonds located at the knees of integrin a 4 C589-C594 and b 7 C494-C526 activated a 4 b 7 . This activated integrin had a unique structure that was different from the typical extended conformation of active integrin. In addition, these activated a 4 b 7 integrins spontaneously clustered on the cell membrane and triggered integrin downstream signaling independent of ligand binding. Although these disulfide bonds were not broken during a 4 b 7 activation by inside-out signaling or Mn 2+ , they could be specifically reduced by 0.1 mM dithiothreitol, a reducing strength that could be produced in vivo under certain conditions. Our findings reveal a novel mechanism of integrin activation under specific reducing conditions by which integrin can signal and promote cell spreading in the absence of ligand.

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Section: Resultssupporting

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Structural Model Constructionmentioning

confidence: 99%

Section: Protein Purificationmentioning

confidence: 99%

See 3 more Smart Citations

Disruption of disulfide-restriction at integrin knees induces activation and ligand-independent signaling of α4β7

Zhang

Pan

et al. 2013

Journal of Cell Science

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Binding of HIV-1 virions to α4β7 expressing cells and impact of antagonizing α4β7 on HIV-1 infection of primary CD4+ T cells

Jin

et al. 2014

Virol. Sin.

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HIV-1 envelope glycoprotein is reported to interact with α4β7, an integrin mediating the homing of lymphocytes to gut-associated lymphoid tissue, but the significance of α4β7 in HIV-1 infection remains controversial. Here, using HIV-1 strain BaL, the gp120 of which was previously shown to be capable of interacting with α4β7, we demonstrated that α4β7 can mediate the binding of whole HIV-1 virions to α4β7-expressing transfectants. We further constructed a cell line stably expressing α4β7 and confirmed the α4β7-mediated HIV-1 binding. In primary lymphocytes with activated α4β7 expression, we also observed significant virus binding which can be inhibited by an anti-α4β7 antibody. Moreover, we investigated the impact of antagonizing α4β7 on HIV-1 infection of primary CD4(+) T cells. In α4β7-activated CD4(+) T cells, both anti-α4β7 antibodies and introduction of short-hairpin RNAs specifically targeting α4β7 resulted in a decreased HIV-1 infection. Our findings indicate that α4β7 may serve as an attachment factor at least for some HIV-1 strains. The established approach provides a promising means for the investigation of other viral strains to understand the potential roles of α4β7 in HIV-1 infection.

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The activated conformation of integrin β7 is a novel multiple myeloma–specific target for CAR T cell therapy

Hosen

Matsunaga

Hasegawa

et al. 2017

Nat Med

121

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Cancer-specific cell-surface antigens are ideal targets for monoclonal antibody (mAb)-based immunotherapy but are likely to have previously been identified in transcriptome or proteome analyses. Here, we show that the active conformer of an integrin can serve as a specific therapeutic target for multiple myeloma (MM). We screened >10,000 anti-MM mAb clones and identified MMG49 as an MM-specific mAb specifically recognizing a subset of integrin β molecules. The MMG49 epitope, in the N-terminal region of the β chain, is predicted to be inaccessible in the resting integrin conformer but exposed in the active conformation. Elevated expression and constitutive activation of integrin β conferred high MMG49 reactivity on MM cells, whereas MMG49 binding was scarcely detectable in other cell types including normal integrin β lymphocytes. T cells transduced with MMG49-derived chimeric antigen receptor (CAR) exerted anti-MM effects without damaging normal hematopoietic cells. Thus, MMG49 CAR T cell therapy is promising for MM, and a receptor protein with a rare but physiologically relevant conformation can serve as a cancer immunotherapy target.

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Identification, Characterization, and Epitope Mapping of Human Monoclonal Antibody J19 That Specifically Recognizes Activated Integrin α4β7

Cited by 9 publications

References 48 publications

Disruption of disulfide-restriction at integrin knees induces activation and ligand-independent signaling of α4β7

Disruption of disulfide-restriction at integrin knees induces activation and ligand-independent signaling of α4β7

Binding of HIV-1 virions to α4β7 expressing cells and impact of antagonizing α4β7 on HIV-1 infection of primary CD4+ T cells

The activated conformation of integrin β7 is a novel multiple myeloma–specific target for CAR T cell therapy

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