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The HIV-1 envelope protein gp120 is captured and displayed for B cell recognition by SIGN-R1(+) lymph node macrophages.

Park C, Arthos J, Cicala C, Kehrl JH - Elife (2015)

Bottom Line: In contrast, two other antigens, phycoerythrin and hen egg lysozyme, were not captured by these cells.Intravital imaging of mouse LNs revealed persistent, but transient interactions between gp120 bearing interfollicular network cells and both trafficking and LN follicle resident gp120 specific B cells.Our findings reveal a specialized LN antigen delivery system poised to deliver gp120 and likely other pathogen derived glycoproteins to B cells.

View Article: PubMed Central - PubMed

Affiliation: B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, Bethesda, United States.

ABSTRACT
The HIV-1 envelope protein gp120 is both the target of neutralizing antibodies and a major focus of vaccine efforts; however how it is delivered to B cells to elicit an antibody response is unknown. Here, we show that following local gp120 injection lymph node (LN) SIGN-R1(+) sinus macrophages located in interfollicular pockets and underlying SIGN-R1(+) macrophages form a cellular network that rapidly captures gp120 from the afferent lymph. In contrast, two other antigens, phycoerythrin and hen egg lysozyme, were not captured by these cells. Intravital imaging of mouse LNs revealed persistent, but transient interactions between gp120 bearing interfollicular network cells and both trafficking and LN follicle resident gp120 specific B cells. The gp120 specific, but not the control B cells repetitively extracted gp120 from the network cells. Our findings reveal a specialized LN antigen delivery system poised to deliver gp120 and likely other pathogen derived glycoproteins to B cells.

No MeSH data available.


Individual b12 HL B cell tracks from b12 HL B cells located in the LNfollicle near the IFC channel following injection of gp120.(A) Six tracks, red lines, and displacements, yellow or cyanarrows, of b12 HL B cells were superimposed on 3-D reconstruction image ofgp120 loaded IFC network cells, green. 3-D reconstruction images weregenerated with 50 μm z-stack volume image. Displacement arrows weregenerated with fragments of the original track, which disconnected at timepoints that showed typical turning or discontinues movement from theoriginal single track. Yellow arrows in each track indicate the startingpoint. Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.(B, C) Each track in (a) was visualized from adifferent angle to see typical tracked cell pattern (approach, survey, moveaway). Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.Each individual track is shown as a single track plot of velocity (solidline) and gp120 intensity (dotted line). Duration is total time span of theoriginal single tracks in a 2 hr intravital TPLSM imaging.DOI:http://dx.doi.org/10.7554/eLife.06467.023
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fig8: Individual b12 HL B cell tracks from b12 HL B cells located in the LNfollicle near the IFC channel following injection of gp120.(A) Six tracks, red lines, and displacements, yellow or cyanarrows, of b12 HL B cells were superimposed on 3-D reconstruction image ofgp120 loaded IFC network cells, green. 3-D reconstruction images weregenerated with 50 μm z-stack volume image. Displacement arrows weregenerated with fragments of the original track, which disconnected at timepoints that showed typical turning or discontinues movement from theoriginal single track. Yellow arrows in each track indicate the startingpoint. Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.(B, C) Each track in (a) was visualized from adifferent angle to see typical tracked cell pattern (approach, survey, moveaway). Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.Each individual track is shown as a single track plot of velocity (solidline) and gp120 intensity (dotted line). Duration is total time span of theoriginal single tracks in a 2 hr intravital TPLSM imaging.DOI:http://dx.doi.org/10.7554/eLife.06467.023

Mentions: To determine whether B cells resident in LN follicles might also acquire cognateantigen from the IFC network, we adoptively transferred b12 HL and wild type (WT) Bcells to recipient mice the day prior to gp120 injection. This allowed the B cells tolocalize in the follicle. Then, we injected gp120 and over the next 2 hr monitoredits uptake by the IFC network and the behavior of B cells in the LN follicle. Asnoted previously the IFC network cells rapidly accumulated gp120 and within 30 minfine cellular processes bearing gp120 became visible along the follicle edge (Figure 7A). Tracking the transferred B cells nearthe follicle edge revealed that the b12 HL B cells moved slower and tended to remainin the imaging space longer resulting in a longer track lengths and increaseddisplacements (Figure 7B). As a consequenceb12 HL B cells accumulated at these sites while the control B cells did not (Figure 7C). The b12 HL B cells made numerous,transient interactions with the gp120 bearing cellular processes (Video 6). Tracking individual b12 HL B cellsrevealed that the B cells slowed as they extracted antigen from the network, afterwhich they sped up and the cell associated gp120 signal declined, whereupon theyre-engaged the network and extracted more gp120 (Figure 7D). Interestingly, the average velocities of both the WT and thegp120 specific B cells increased over time following the gp120 injection (Figure 7E). Detailed analyses of six tracks fromB cells located in the LN follicle and near the intrafollicular channel are shown(Figure 8). These results show that antigenloaded IFC can provide a source of antigen for cognate B cells traversing the edge ofthe LN follicle and perhaps provide signals that enhance B cell motility in thefollicle.10.7554/eLife.06467.021Figure 7.LN follicle B cells that express the b12 antigen receptor can extractgp120 from IFC network cells.


The HIV-1 envelope protein gp120 is captured and displayed for B cell recognition by SIGN-R1(+) lymph node macrophages.

Park C, Arthos J, Cicala C, Kehrl JH - Elife (2015)

Individual b12 HL B cell tracks from b12 HL B cells located in the LNfollicle near the IFC channel following injection of gp120.(A) Six tracks, red lines, and displacements, yellow or cyanarrows, of b12 HL B cells were superimposed on 3-D reconstruction image ofgp120 loaded IFC network cells, green. 3-D reconstruction images weregenerated with 50 μm z-stack volume image. Displacement arrows weregenerated with fragments of the original track, which disconnected at timepoints that showed typical turning or discontinues movement from theoriginal single track. Yellow arrows in each track indicate the startingpoint. Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.(B, C) Each track in (a) was visualized from adifferent angle to see typical tracked cell pattern (approach, survey, moveaway). Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.Each individual track is shown as a single track plot of velocity (solidline) and gp120 intensity (dotted line). Duration is total time span of theoriginal single tracks in a 2 hr intravital TPLSM imaging.DOI:http://dx.doi.org/10.7554/eLife.06467.023
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Related In: Results  -  Collection

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fig8: Individual b12 HL B cell tracks from b12 HL B cells located in the LNfollicle near the IFC channel following injection of gp120.(A) Six tracks, red lines, and displacements, yellow or cyanarrows, of b12 HL B cells were superimposed on 3-D reconstruction image ofgp120 loaded IFC network cells, green. 3-D reconstruction images weregenerated with 50 μm z-stack volume image. Displacement arrows weregenerated with fragments of the original track, which disconnected at timepoints that showed typical turning or discontinues movement from theoriginal single track. Yellow arrows in each track indicate the startingpoint. Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.(B, C) Each track in (a) was visualized from adifferent angle to see typical tracked cell pattern (approach, survey, moveaway). Scale bar is 50 μm. Grid spacing in 3-D view is 10 μm.Each individual track is shown as a single track plot of velocity (solidline) and gp120 intensity (dotted line). Duration is total time span of theoriginal single tracks in a 2 hr intravital TPLSM imaging.DOI:http://dx.doi.org/10.7554/eLife.06467.023
Mentions: To determine whether B cells resident in LN follicles might also acquire cognateantigen from the IFC network, we adoptively transferred b12 HL and wild type (WT) Bcells to recipient mice the day prior to gp120 injection. This allowed the B cells tolocalize in the follicle. Then, we injected gp120 and over the next 2 hr monitoredits uptake by the IFC network and the behavior of B cells in the LN follicle. Asnoted previously the IFC network cells rapidly accumulated gp120 and within 30 minfine cellular processes bearing gp120 became visible along the follicle edge (Figure 7A). Tracking the transferred B cells nearthe follicle edge revealed that the b12 HL B cells moved slower and tended to remainin the imaging space longer resulting in a longer track lengths and increaseddisplacements (Figure 7B). As a consequenceb12 HL B cells accumulated at these sites while the control B cells did not (Figure 7C). The b12 HL B cells made numerous,transient interactions with the gp120 bearing cellular processes (Video 6). Tracking individual b12 HL B cellsrevealed that the B cells slowed as they extracted antigen from the network, afterwhich they sped up and the cell associated gp120 signal declined, whereupon theyre-engaged the network and extracted more gp120 (Figure 7D). Interestingly, the average velocities of both the WT and thegp120 specific B cells increased over time following the gp120 injection (Figure 7E). Detailed analyses of six tracks fromB cells located in the LN follicle and near the intrafollicular channel are shown(Figure 8). These results show that antigenloaded IFC can provide a source of antigen for cognate B cells traversing the edge ofthe LN follicle and perhaps provide signals that enhance B cell motility in thefollicle.10.7554/eLife.06467.021Figure 7.LN follicle B cells that express the b12 antigen receptor can extractgp120 from IFC network cells.

Bottom Line: In contrast, two other antigens, phycoerythrin and hen egg lysozyme, were not captured by these cells.Intravital imaging of mouse LNs revealed persistent, but transient interactions between gp120 bearing interfollicular network cells and both trafficking and LN follicle resident gp120 specific B cells.Our findings reveal a specialized LN antigen delivery system poised to deliver gp120 and likely other pathogen derived glycoproteins to B cells.

View Article: PubMed Central - PubMed

Affiliation: B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, Bethesda, United States.

ABSTRACT
The HIV-1 envelope protein gp120 is both the target of neutralizing antibodies and a major focus of vaccine efforts; however how it is delivered to B cells to elicit an antibody response is unknown. Here, we show that following local gp120 injection lymph node (LN) SIGN-R1(+) sinus macrophages located in interfollicular pockets and underlying SIGN-R1(+) macrophages form a cellular network that rapidly captures gp120 from the afferent lymph. In contrast, two other antigens, phycoerythrin and hen egg lysozyme, were not captured by these cells. Intravital imaging of mouse LNs revealed persistent, but transient interactions between gp120 bearing interfollicular network cells and both trafficking and LN follicle resident gp120 specific B cells. The gp120 specific, but not the control B cells repetitively extracted gp120 from the network cells. Our findings reveal a specialized LN antigen delivery system poised to deliver gp120 and likely other pathogen derived glycoproteins to B cells.

No MeSH data available.