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Tumor necrosis factor-dependent segmental control of MIG expression by high endothelial venules in inflamed lymph nodes regulates monocyte recruitment.

Janatpour MJ, Hudak S, Sathe M, Sedgwick JD, McEvoy LM - J. Exp. Med. (2001)

Bottom Line: Quantitative PCR analyses revealed the upregulation of many chemokines in the inflamed lymph node, including MCP-1 and MIG.HEVs did not express detectable levels of MCP-1; however, a subset of HEVs in inflamed lymph nodes in wild-type (but not tumor necrosis factor [TNF] mice) expressed MIG and this subset of HEVs preferentially supported monocyte binding.Together, these results suggest that the lymph node microenvironment can dictate the nature of molecules expressed on HEV subsets in a TNF-dependent fashion and that inflammation-induced MIG expression by HEVs can mediate monocyte recruitment.

View Article: PubMed Central - PubMed

Affiliation: DNAX Research Institute, Inc., Palo Alto, CA 94304, USA.

ABSTRACT
Monocytes recruited from the blood are key contributors to the nature of an immune response. While monocyte recruitment in a subset of immunopathologies has been well studied and largely attributed to the chemokine monocyte chemoattractant protein (MCP)-1, mechanisms mediating such recruitment to other sites of inflammation remain elusive. Here, we showed that localized inflammation resulted in an increased binding of monocytes to perifollicular high endothelial venules (HEVs) of lymph nodes draining a local inflammatory site. Quantitative PCR analyses revealed the upregulation of many chemokines in the inflamed lymph node, including MCP-1 and MIG. HEVs did not express detectable levels of MCP-1; however, a subset of HEVs in inflamed lymph nodes in wild-type (but not tumor necrosis factor [TNF] mice) expressed MIG and this subset of HEVs preferentially supported monocyte binding. Expression of CXCR3, the receptor for MIG, was detected on a small subset of peripheral blood monocytes and on a significant percentage of recruited monocytes. Most importantly, in both ex vivo and in vivo assays, neutralizing anti-MIG antibodies blocked monocyte binding to inflamed lymph node HEVs. Together, these results suggest that the lymph node microenvironment can dictate the nature of molecules expressed on HEV subsets in a TNF-dependent fashion and that inflammation-induced MIG expression by HEVs can mediate monocyte recruitment.

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A function-perturbing antibody to MIG blocks monocyte binding to inflamed HEVs in vivo. To test whether MIG plays a role in monocyte recruitment to inflamed lymph nodes in vivo, inflammation was induced in both forepaws of 12 mice. The mice were divided into two groups, each receiving either a function-perturbing antibody to MIG or a control antibody intraperitoneally. In one experiment (Exp. 2), 12 mice that were not inflamed (white bars) also received the antibody treatment. Draining lymph nodes were isolated and sectioned. (A) To confirm that the antibodies reached and bound the HEVs, sections were stained with a FITC-conjugated secondary antibody to visualize the intraperitoneally injected antibody. Sections were costained with an antibody against B220. The neutralizing antibody to MIG localized to the HEV (right, green). (B) The in vivo snapshot assay was performed to determine the percentage of HEVs with a bound monocyte in the presence of either a MIG neutralizing antibody (αMIG) or the control (Cont Ab). 15–20% of inflamed HEVs had a bound monocyte in the presence of the control antibody, similar to what was observed in the absence of antibody (compare No Ab to Cont Ab, black bars). In the presence of a MIG neutralizing antibody this percentage was reduced to levels equivalent to uninflamed controls (white bars).
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fig4: A function-perturbing antibody to MIG blocks monocyte binding to inflamed HEVs in vivo. To test whether MIG plays a role in monocyte recruitment to inflamed lymph nodes in vivo, inflammation was induced in both forepaws of 12 mice. The mice were divided into two groups, each receiving either a function-perturbing antibody to MIG or a control antibody intraperitoneally. In one experiment (Exp. 2), 12 mice that were not inflamed (white bars) also received the antibody treatment. Draining lymph nodes were isolated and sectioned. (A) To confirm that the antibodies reached and bound the HEVs, sections were stained with a FITC-conjugated secondary antibody to visualize the intraperitoneally injected antibody. Sections were costained with an antibody against B220. The neutralizing antibody to MIG localized to the HEV (right, green). (B) The in vivo snapshot assay was performed to determine the percentage of HEVs with a bound monocyte in the presence of either a MIG neutralizing antibody (αMIG) or the control (Cont Ab). 15–20% of inflamed HEVs had a bound monocyte in the presence of the control antibody, similar to what was observed in the absence of antibody (compare No Ab to Cont Ab, black bars). In the presence of a MIG neutralizing antibody this percentage was reduced to levels equivalent to uninflamed controls (white bars).

Mentions: To confirm that the antibodies reached and bound the HEVs, sections were stained with a FITC-conjugated secondary antibody to localize the intraperitoneally injected antibody. As shown in Fig. 4 A, the neutralizing antibody to MIG (but not the control antibody) localized to the HEVs (right panel, green) confirming display of MIG on the HEVs and presence of neutralizing antibody during the peak of monocyte recruitment.


Tumor necrosis factor-dependent segmental control of MIG expression by high endothelial venules in inflamed lymph nodes regulates monocyte recruitment.

Janatpour MJ, Hudak S, Sathe M, Sedgwick JD, McEvoy LM - J. Exp. Med. (2001)

A function-perturbing antibody to MIG blocks monocyte binding to inflamed HEVs in vivo. To test whether MIG plays a role in monocyte recruitment to inflamed lymph nodes in vivo, inflammation was induced in both forepaws of 12 mice. The mice were divided into two groups, each receiving either a function-perturbing antibody to MIG or a control antibody intraperitoneally. In one experiment (Exp. 2), 12 mice that were not inflamed (white bars) also received the antibody treatment. Draining lymph nodes were isolated and sectioned. (A) To confirm that the antibodies reached and bound the HEVs, sections were stained with a FITC-conjugated secondary antibody to visualize the intraperitoneally injected antibody. Sections were costained with an antibody against B220. The neutralizing antibody to MIG localized to the HEV (right, green). (B) The in vivo snapshot assay was performed to determine the percentage of HEVs with a bound monocyte in the presence of either a MIG neutralizing antibody (αMIG) or the control (Cont Ab). 15–20% of inflamed HEVs had a bound monocyte in the presence of the control antibody, similar to what was observed in the absence of antibody (compare No Ab to Cont Ab, black bars). In the presence of a MIG neutralizing antibody this percentage was reduced to levels equivalent to uninflamed controls (white bars).
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Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195975&req=5

fig4: A function-perturbing antibody to MIG blocks monocyte binding to inflamed HEVs in vivo. To test whether MIG plays a role in monocyte recruitment to inflamed lymph nodes in vivo, inflammation was induced in both forepaws of 12 mice. The mice were divided into two groups, each receiving either a function-perturbing antibody to MIG or a control antibody intraperitoneally. In one experiment (Exp. 2), 12 mice that were not inflamed (white bars) also received the antibody treatment. Draining lymph nodes were isolated and sectioned. (A) To confirm that the antibodies reached and bound the HEVs, sections were stained with a FITC-conjugated secondary antibody to visualize the intraperitoneally injected antibody. Sections were costained with an antibody against B220. The neutralizing antibody to MIG localized to the HEV (right, green). (B) The in vivo snapshot assay was performed to determine the percentage of HEVs with a bound monocyte in the presence of either a MIG neutralizing antibody (αMIG) or the control (Cont Ab). 15–20% of inflamed HEVs had a bound monocyte in the presence of the control antibody, similar to what was observed in the absence of antibody (compare No Ab to Cont Ab, black bars). In the presence of a MIG neutralizing antibody this percentage was reduced to levels equivalent to uninflamed controls (white bars).
Mentions: To confirm that the antibodies reached and bound the HEVs, sections were stained with a FITC-conjugated secondary antibody to localize the intraperitoneally injected antibody. As shown in Fig. 4 A, the neutralizing antibody to MIG (but not the control antibody) localized to the HEVs (right panel, green) confirming display of MIG on the HEVs and presence of neutralizing antibody during the peak of monocyte recruitment.

Bottom Line: Quantitative PCR analyses revealed the upregulation of many chemokines in the inflamed lymph node, including MCP-1 and MIG.HEVs did not express detectable levels of MCP-1; however, a subset of HEVs in inflamed lymph nodes in wild-type (but not tumor necrosis factor [TNF] mice) expressed MIG and this subset of HEVs preferentially supported monocyte binding.Together, these results suggest that the lymph node microenvironment can dictate the nature of molecules expressed on HEV subsets in a TNF-dependent fashion and that inflammation-induced MIG expression by HEVs can mediate monocyte recruitment.

View Article: PubMed Central - PubMed

Affiliation: DNAX Research Institute, Inc., Palo Alto, CA 94304, USA.

ABSTRACT
Monocytes recruited from the blood are key contributors to the nature of an immune response. While monocyte recruitment in a subset of immunopathologies has been well studied and largely attributed to the chemokine monocyte chemoattractant protein (MCP)-1, mechanisms mediating such recruitment to other sites of inflammation remain elusive. Here, we showed that localized inflammation resulted in an increased binding of monocytes to perifollicular high endothelial venules (HEVs) of lymph nodes draining a local inflammatory site. Quantitative PCR analyses revealed the upregulation of many chemokines in the inflamed lymph node, including MCP-1 and MIG. HEVs did not express detectable levels of MCP-1; however, a subset of HEVs in inflamed lymph nodes in wild-type (but not tumor necrosis factor [TNF] mice) expressed MIG and this subset of HEVs preferentially supported monocyte binding. Expression of CXCR3, the receptor for MIG, was detected on a small subset of peripheral blood monocytes and on a significant percentage of recruited monocytes. Most importantly, in both ex vivo and in vivo assays, neutralizing anti-MIG antibodies blocked monocyte binding to inflamed lymph node HEVs. Together, these results suggest that the lymph node microenvironment can dictate the nature of molecules expressed on HEV subsets in a TNF-dependent fashion and that inflammation-induced MIG expression by HEVs can mediate monocyte recruitment.

Show MeSH
Related in: MedlinePlus