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Inflammatory chemokine transport and presentation in HEV: a remote control mechanism for monocyte recruitment to lymph nodes in inflamed tissues.

Palframan RT, Jung S, Cheng G, Weninger W, Luo Y, Dorf M, Littman DR, Rollins BJ, Zweerink H, Rot A, von Andrian UH - J. Exp. Med. (2001)

Bottom Line: MCP-1 mRNA in inflamed skin was over 100-fold upregulated and paralleled MCP-1 protein levels, whereas in draining LNs MCP-1 mRNA induction was much weaker and occurred only after a pronounced rise in MCP-1 protein.Thus, MCP-1 in draining LNs was primarily derived from inflamed skin.These findings demonstrate that inflamed peripheral tissues project their local chemokine profile to HEVs in draining LNs and thereby exert "remote control" over the composition of leukocyte populations that home to these organs from the blood.

View Article: PubMed Central - PubMed

Affiliation: Center for Blood Research, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT
Interstitial fluid is constantly drained into lymph nodes (LNs) via afferent lymph vessels. This conduit enables monocyte-derived macrophages and dendritic cells to access LNs from peripheral tissues. We show that during inflammation in the skin, a second recruitment pathway is evoked that recruits large numbers of blood-borne monocytes to LNs via high endothelial venules (HEVs). Inhibition of monocyte chemoattractant protein (MCP)-1 blocked this inflammation-induced monocyte homing to LNs. MCP-1 mRNA in inflamed skin was over 100-fold upregulated and paralleled MCP-1 protein levels, whereas in draining LNs MCP-1 mRNA induction was much weaker and occurred only after a pronounced rise in MCP-1 protein. Thus, MCP-1 in draining LNs was primarily derived from inflamed skin. In MCP-1(-/-) mice, intracutaneously injected MCP-1 accumulated rapidly in the draining LNs where it enhanced monocyte recruitment. Intravital microscopy showed that skin-derived MCP-1 was transported via the lymph to the luminal surface of HEVs where it triggered integrin-dependent arrest of rolling monocytes. These findings demonstrate that inflamed peripheral tissues project their local chemokine profile to HEVs in draining LNs and thereby exert "remote control" over the composition of leukocyte populations that home to these organs from the blood.

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Intracutaneous injection of recombinant MCP-1 into MCP-1−/− mice enhances monocyte homing in draining PLNs. MCP-1−/− mice with cutaneous inflammation in both flanks and the right lateral chest were injected intracutaneously with recombinant murine MCP-1 (25 μg) over the left flank and vehicle (50 μl PBS) elsewhere, as described in Materials and Methods. 10 min later, 1.5 × 107 CX3CR1+/GFP donor PBMCs (containing ∼106 GFP+ cells) were injected intravenously. (A) FACS® plots show the frequency of GFP+NK1.1− monocytes after 90 min in recipient blood, the PLN draining MCP-1–injected skin (subiliac LN plus MCP-1), the contralateral subiliac LNs (subiliac LN plus vehicle), and the inflamed brachial LN (brachial LN plus vehicle) from the same mouse. 6 × 105 events are plotted in each histogram. (B) GFPMED, but not GFPHIGH CX3CR+/GFP cells accumulate preferentially in the subiliac LN that drained the MCP-1 injection site. Mean ± SEM of three separate experiments are shown. (C) MCP-1 protein concentration in inflamed left and right subiliac LNs and right brachial LNs 90 min after intracutaneous injection of recombinant murine MCP-1 or vehicle. Each curve reflects MCP-1 concentration in three PLNs measured in the same mouse.
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fig5: Intracutaneous injection of recombinant MCP-1 into MCP-1−/− mice enhances monocyte homing in draining PLNs. MCP-1−/− mice with cutaneous inflammation in both flanks and the right lateral chest were injected intracutaneously with recombinant murine MCP-1 (25 μg) over the left flank and vehicle (50 μl PBS) elsewhere, as described in Materials and Methods. 10 min later, 1.5 × 107 CX3CR1+/GFP donor PBMCs (containing ∼106 GFP+ cells) were injected intravenously. (A) FACS® plots show the frequency of GFP+NK1.1− monocytes after 90 min in recipient blood, the PLN draining MCP-1–injected skin (subiliac LN plus MCP-1), the contralateral subiliac LNs (subiliac LN plus vehicle), and the inflamed brachial LN (brachial LN plus vehicle) from the same mouse. 6 × 105 events are plotted in each histogram. (B) GFPMED, but not GFPHIGH CX3CR+/GFP cells accumulate preferentially in the subiliac LN that drained the MCP-1 injection site. Mean ± SEM of three separate experiments are shown. (C) MCP-1 protein concentration in inflamed left and right subiliac LNs and right brachial LNs 90 min after intracutaneous injection of recombinant murine MCP-1 or vehicle. Each curve reflects MCP-1 concentration in three PLNs measured in the same mouse.

Mentions: After injection of 25 μg recombinant MCP-1 in the left flank some intracutaneously injected chemokine was found in the contralateral subiliac LN and, to a lesser degree, the brachial LN (Fig. 5 C). When tissues were harvested from MCP-1−/− mice 90 min after intracutaneous injection, optical density measurements in our ELISA assay were at least 10-fold higher in PLNs of MCP-1 recipients than in PLNs of a MCP-1−/− mouse that was not injected with chemokine (data not shown). This chemokine “spillover” is consistent with earlier experiments with SLC (17) and the experiments described previously using a lower dose (1 μg) of MCP-1. Thus, it seems plausible that some monocytes that homed to the contralateral subiliac and brachial PLNs were recruited by MCP-1 that was transported there from the injection site. Despite this, the number of monocytes in the right brachial LN was significantly smaller than in the MCP-1 draining left subiliac LN (P < 0.03), whereas intermediate monocyte numbers were present in the contralateral subiliac LN (P > 0.05 vs. right brachial and left subiliac LNs). Thus, homing of GFPMED (but not GFPHIGH) cells to recipient PLNs correlated with the presence of MCP-1 indicating that remotely-administered MCP-1 stimulates monocyte recruitment into draining PLNs of MCP-1−/− mice.


Inflammatory chemokine transport and presentation in HEV: a remote control mechanism for monocyte recruitment to lymph nodes in inflamed tissues.

Palframan RT, Jung S, Cheng G, Weninger W, Luo Y, Dorf M, Littman DR, Rollins BJ, Zweerink H, Rot A, von Andrian UH - J. Exp. Med. (2001)

Intracutaneous injection of recombinant MCP-1 into MCP-1−/− mice enhances monocyte homing in draining PLNs. MCP-1−/− mice with cutaneous inflammation in both flanks and the right lateral chest were injected intracutaneously with recombinant murine MCP-1 (25 μg) over the left flank and vehicle (50 μl PBS) elsewhere, as described in Materials and Methods. 10 min later, 1.5 × 107 CX3CR1+/GFP donor PBMCs (containing ∼106 GFP+ cells) were injected intravenously. (A) FACS® plots show the frequency of GFP+NK1.1− monocytes after 90 min in recipient blood, the PLN draining MCP-1–injected skin (subiliac LN plus MCP-1), the contralateral subiliac LNs (subiliac LN plus vehicle), and the inflamed brachial LN (brachial LN plus vehicle) from the same mouse. 6 × 105 events are plotted in each histogram. (B) GFPMED, but not GFPHIGH CX3CR+/GFP cells accumulate preferentially in the subiliac LN that drained the MCP-1 injection site. Mean ± SEM of three separate experiments are shown. (C) MCP-1 protein concentration in inflamed left and right subiliac LNs and right brachial LNs 90 min after intracutaneous injection of recombinant murine MCP-1 or vehicle. Each curve reflects MCP-1 concentration in three PLNs measured in the same mouse.
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Related In: Results  -  Collection

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fig5: Intracutaneous injection of recombinant MCP-1 into MCP-1−/− mice enhances monocyte homing in draining PLNs. MCP-1−/− mice with cutaneous inflammation in both flanks and the right lateral chest were injected intracutaneously with recombinant murine MCP-1 (25 μg) over the left flank and vehicle (50 μl PBS) elsewhere, as described in Materials and Methods. 10 min later, 1.5 × 107 CX3CR1+/GFP donor PBMCs (containing ∼106 GFP+ cells) were injected intravenously. (A) FACS® plots show the frequency of GFP+NK1.1− monocytes after 90 min in recipient blood, the PLN draining MCP-1–injected skin (subiliac LN plus MCP-1), the contralateral subiliac LNs (subiliac LN plus vehicle), and the inflamed brachial LN (brachial LN plus vehicle) from the same mouse. 6 × 105 events are plotted in each histogram. (B) GFPMED, but not GFPHIGH CX3CR+/GFP cells accumulate preferentially in the subiliac LN that drained the MCP-1 injection site. Mean ± SEM of three separate experiments are shown. (C) MCP-1 protein concentration in inflamed left and right subiliac LNs and right brachial LNs 90 min after intracutaneous injection of recombinant murine MCP-1 or vehicle. Each curve reflects MCP-1 concentration in three PLNs measured in the same mouse.
Mentions: After injection of 25 μg recombinant MCP-1 in the left flank some intracutaneously injected chemokine was found in the contralateral subiliac LN and, to a lesser degree, the brachial LN (Fig. 5 C). When tissues were harvested from MCP-1−/− mice 90 min after intracutaneous injection, optical density measurements in our ELISA assay were at least 10-fold higher in PLNs of MCP-1 recipients than in PLNs of a MCP-1−/− mouse that was not injected with chemokine (data not shown). This chemokine “spillover” is consistent with earlier experiments with SLC (17) and the experiments described previously using a lower dose (1 μg) of MCP-1. Thus, it seems plausible that some monocytes that homed to the contralateral subiliac and brachial PLNs were recruited by MCP-1 that was transported there from the injection site. Despite this, the number of monocytes in the right brachial LN was significantly smaller than in the MCP-1 draining left subiliac LN (P < 0.03), whereas intermediate monocyte numbers were present in the contralateral subiliac LN (P > 0.05 vs. right brachial and left subiliac LNs). Thus, homing of GFPMED (but not GFPHIGH) cells to recipient PLNs correlated with the presence of MCP-1 indicating that remotely-administered MCP-1 stimulates monocyte recruitment into draining PLNs of MCP-1−/− mice.

Bottom Line: MCP-1 mRNA in inflamed skin was over 100-fold upregulated and paralleled MCP-1 protein levels, whereas in draining LNs MCP-1 mRNA induction was much weaker and occurred only after a pronounced rise in MCP-1 protein.Thus, MCP-1 in draining LNs was primarily derived from inflamed skin.These findings demonstrate that inflamed peripheral tissues project their local chemokine profile to HEVs in draining LNs and thereby exert "remote control" over the composition of leukocyte populations that home to these organs from the blood.

View Article: PubMed Central - PubMed

Affiliation: Center for Blood Research, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT
Interstitial fluid is constantly drained into lymph nodes (LNs) via afferent lymph vessels. This conduit enables monocyte-derived macrophages and dendritic cells to access LNs from peripheral tissues. We show that during inflammation in the skin, a second recruitment pathway is evoked that recruits large numbers of blood-borne monocytes to LNs via high endothelial venules (HEVs). Inhibition of monocyte chemoattractant protein (MCP)-1 blocked this inflammation-induced monocyte homing to LNs. MCP-1 mRNA in inflamed skin was over 100-fold upregulated and paralleled MCP-1 protein levels, whereas in draining LNs MCP-1 mRNA induction was much weaker and occurred only after a pronounced rise in MCP-1 protein. Thus, MCP-1 in draining LNs was primarily derived from inflamed skin. In MCP-1(-/-) mice, intracutaneously injected MCP-1 accumulated rapidly in the draining LNs where it enhanced monocyte recruitment. Intravital microscopy showed that skin-derived MCP-1 was transported via the lymph to the luminal surface of HEVs where it triggered integrin-dependent arrest of rolling monocytes. These findings demonstrate that inflamed peripheral tissues project their local chemokine profile to HEVs in draining LNs and thereby exert "remote control" over the composition of leukocyte populations that home to these organs from the blood.

Show MeSH
Related in: MedlinePlus