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Normalization of the lymph node T cell stromal microenvironment in lpr/lpr mice is associated with SU5416-induced reduction in autoantibodies.

Chyou S, Tian S, Ekland EH, Lu TT - PLoS ONE (2012)

Bottom Line: Surprisingly, treatment with SU5416, an inhibitor of VEGF and other receptor tyrosine kinases, did not have sustained effects in inhibiting vascular growth, but attenuated the anti-dsDNA response and altered the phenotype of the double negative T cells that are expanded in these mice.In examining for anatomic correlates of these immunologic changes, we found that the double negative T cells are localized within ectopic follicles around a central B cell patch and that these T cell-rich areas lack the T zone stromal protein ER-TR7 as well as other elements of a normal T zone microenvironment.Recent studies have shown a regulatory role for T zone stromal elements.

View Article: PubMed Central - PubMed

Affiliation: Autoimmunity and Inflammation Program, Hospital for Special Surgery, New York, New York, United States of America.

ABSTRACT
The vascular-stromal elements of lymph nodes can play important roles in regulating the activities of the lymphocytes within. During model immune responses, the vascular-stromal compartment has been shown to undergo proliferative expansion and functional alterations. The state of the vascular-stromal compartment and the potential importance of this compartment in a spontaneous, chronic model of autoimmunity have not been well studied. Here, we characterize the vascular expansion in MRL-lpr/lpr lymph nodes and attempt to ask whether inhibiting this expansion can interfere with autoantibody generation. We show that characteristics of vascular expansion in enlarging MRL-lpr/lpr lymph nodes resemble that of the VEGF-dependent expansion that occurs in wild-type mice after model immunization. Surprisingly, treatment with SU5416, an inhibitor of VEGF and other receptor tyrosine kinases, did not have sustained effects in inhibiting vascular growth, but attenuated the anti-dsDNA response and altered the phenotype of the double negative T cells that are expanded in these mice. In examining for anatomic correlates of these immunologic changes, we found that the double negative T cells are localized within ectopic follicles around a central B cell patch and that these T cell-rich areas lack the T zone stromal protein ER-TR7 as well as other elements of a normal T zone microenvironment. SU5416 treatment disrupted these follicles and normalized the association between T zone microenvironmental elements and T cell-rich areas. Recent studies have shown a regulatory role for T zone stromal elements. Thus, our findings of the association of anti-dsDNA responses, double negative T cell phenotype, and altered lymphocyte microenvironment suggest the possibility that lymphocyte localization in ectopic follicles protects them from regulation by T zone stromal elements and functions to maintain autoimmune responses. Potentially, altering the lymphocyte microenvironment that is set up by the vascular-stromal compartment can be a means by which to control undesired autoimmune responses.

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SU5416 induces infiltration of ER-TR7 into the B cell areas within ectopic follicles.MRL-lpr-lpr mice were treated with SU5416 or DMSO vehicle for 11.5 weeks starting at 8 weeks of age and lymph nodes were examined. For comparison to a stimulated wild-type lymph node, 10 week old MRL+/+ mice were immunized with OVA/CFA and draining brachial lymph nodes were examined at day 8. (A, D) nearby sections from a single brachial lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (B, E) Nearby sections from a single axillary lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (C,F) Nearby sections from a single axillary lymph node from a SU5416-treated MRL-lpr/lpr mouse were stained as indicated. (G) Higher magnification of B cell follicle border indicated in (D, arrow). (H) Higher magnification of ectopic follicle border indicated in (E, arrow). (I, J) Higher magnification of border of B cell areas indicated in (F). (I) is magnification of area denoted by single arrow and (J) is magnification of area denoted by double arrows. Scale bars represent 500 um.
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pone-0032828-g004: SU5416 induces infiltration of ER-TR7 into the B cell areas within ectopic follicles.MRL-lpr-lpr mice were treated with SU5416 or DMSO vehicle for 11.5 weeks starting at 8 weeks of age and lymph nodes were examined. For comparison to a stimulated wild-type lymph node, 10 week old MRL+/+ mice were immunized with OVA/CFA and draining brachial lymph nodes were examined at day 8. (A, D) nearby sections from a single brachial lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (B, E) Nearby sections from a single axillary lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (C,F) Nearby sections from a single axillary lymph node from a SU5416-treated MRL-lpr/lpr mouse were stained as indicated. (G) Higher magnification of B cell follicle border indicated in (D, arrow). (H) Higher magnification of ectopic follicle border indicated in (E, arrow). (I, J) Higher magnification of border of B cell areas indicated in (F). (I) is magnification of area denoted by single arrow and (J) is magnification of area denoted by double arrows. Scale bars represent 500 um.

Mentions: We examined the distribution of ER-TR7, a component of the extracellular matrix secreted by FRCs [27], to better understand the alterations in the lymph node architecture in the MRL-lpr/lpr mice with and without SU5416 treatment. ER-TR7 staining is normally quite bright and relatively disorganized in the medulla (Fig. 3Fi, 3G) while it shows a distinct reticular pattern in the T zone and (Fig. 3Fi, 3H). It is normally largely excluded from the B cell follicles, defining the border between the T zone and the B cell follicles [24]–[27] (see Fig. 3H). In the MRL-lpr/lpr nodes, bright medullary-type ER-TR7 staining could be observed in the medullary cord-like areas (Fig. 3Fiii double asterisks and Fig. 3I). In the areas occupied by syndecannegCD3hi T cells (Fig. 3Aiii asterisks, 3Biii asterisks), normal T zone reticular ER-TR7 staining was seen (Fig. 3Fiii asterisks, 3J). Remarkably, despite the T cells within the ectopic follicles (Fig. 3Aii–iii, 4B), only sparse ERTR7 staining was seen within the ectopic follicles (Fig. 3Fii–iii, 4E). ER-TR7, then, appeared excluded from the zone of double negative T cells within the ectopic follicles in MRL-lpr/lpr mice.


Normalization of the lymph node T cell stromal microenvironment in lpr/lpr mice is associated with SU5416-induced reduction in autoantibodies.

Chyou S, Tian S, Ekland EH, Lu TT - PLoS ONE (2012)

SU5416 induces infiltration of ER-TR7 into the B cell areas within ectopic follicles.MRL-lpr-lpr mice were treated with SU5416 or DMSO vehicle for 11.5 weeks starting at 8 weeks of age and lymph nodes were examined. For comparison to a stimulated wild-type lymph node, 10 week old MRL+/+ mice were immunized with OVA/CFA and draining brachial lymph nodes were examined at day 8. (A, D) nearby sections from a single brachial lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (B, E) Nearby sections from a single axillary lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (C,F) Nearby sections from a single axillary lymph node from a SU5416-treated MRL-lpr/lpr mouse were stained as indicated. (G) Higher magnification of B cell follicle border indicated in (D, arrow). (H) Higher magnification of ectopic follicle border indicated in (E, arrow). (I, J) Higher magnification of border of B cell areas indicated in (F). (I) is magnification of area denoted by single arrow and (J) is magnification of area denoted by double arrows. Scale bars represent 500 um.
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pone-0032828-g004: SU5416 induces infiltration of ER-TR7 into the B cell areas within ectopic follicles.MRL-lpr-lpr mice were treated with SU5416 or DMSO vehicle for 11.5 weeks starting at 8 weeks of age and lymph nodes were examined. For comparison to a stimulated wild-type lymph node, 10 week old MRL+/+ mice were immunized with OVA/CFA and draining brachial lymph nodes were examined at day 8. (A, D) nearby sections from a single brachial lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (B, E) Nearby sections from a single axillary lymph node from a DMSO-treated MRL-lpr/lpr mouse were stained as indicated. (C,F) Nearby sections from a single axillary lymph node from a SU5416-treated MRL-lpr/lpr mouse were stained as indicated. (G) Higher magnification of B cell follicle border indicated in (D, arrow). (H) Higher magnification of ectopic follicle border indicated in (E, arrow). (I, J) Higher magnification of border of B cell areas indicated in (F). (I) is magnification of area denoted by single arrow and (J) is magnification of area denoted by double arrows. Scale bars represent 500 um.
Mentions: We examined the distribution of ER-TR7, a component of the extracellular matrix secreted by FRCs [27], to better understand the alterations in the lymph node architecture in the MRL-lpr/lpr mice with and without SU5416 treatment. ER-TR7 staining is normally quite bright and relatively disorganized in the medulla (Fig. 3Fi, 3G) while it shows a distinct reticular pattern in the T zone and (Fig. 3Fi, 3H). It is normally largely excluded from the B cell follicles, defining the border between the T zone and the B cell follicles [24]–[27] (see Fig. 3H). In the MRL-lpr/lpr nodes, bright medullary-type ER-TR7 staining could be observed in the medullary cord-like areas (Fig. 3Fiii double asterisks and Fig. 3I). In the areas occupied by syndecannegCD3hi T cells (Fig. 3Aiii asterisks, 3Biii asterisks), normal T zone reticular ER-TR7 staining was seen (Fig. 3Fiii asterisks, 3J). Remarkably, despite the T cells within the ectopic follicles (Fig. 3Aii–iii, 4B), only sparse ERTR7 staining was seen within the ectopic follicles (Fig. 3Fii–iii, 4E). ER-TR7, then, appeared excluded from the zone of double negative T cells within the ectopic follicles in MRL-lpr/lpr mice.

Bottom Line: Surprisingly, treatment with SU5416, an inhibitor of VEGF and other receptor tyrosine kinases, did not have sustained effects in inhibiting vascular growth, but attenuated the anti-dsDNA response and altered the phenotype of the double negative T cells that are expanded in these mice.In examining for anatomic correlates of these immunologic changes, we found that the double negative T cells are localized within ectopic follicles around a central B cell patch and that these T cell-rich areas lack the T zone stromal protein ER-TR7 as well as other elements of a normal T zone microenvironment.Recent studies have shown a regulatory role for T zone stromal elements.

View Article: PubMed Central - PubMed

Affiliation: Autoimmunity and Inflammation Program, Hospital for Special Surgery, New York, New York, United States of America.

ABSTRACT
The vascular-stromal elements of lymph nodes can play important roles in regulating the activities of the lymphocytes within. During model immune responses, the vascular-stromal compartment has been shown to undergo proliferative expansion and functional alterations. The state of the vascular-stromal compartment and the potential importance of this compartment in a spontaneous, chronic model of autoimmunity have not been well studied. Here, we characterize the vascular expansion in MRL-lpr/lpr lymph nodes and attempt to ask whether inhibiting this expansion can interfere with autoantibody generation. We show that characteristics of vascular expansion in enlarging MRL-lpr/lpr lymph nodes resemble that of the VEGF-dependent expansion that occurs in wild-type mice after model immunization. Surprisingly, treatment with SU5416, an inhibitor of VEGF and other receptor tyrosine kinases, did not have sustained effects in inhibiting vascular growth, but attenuated the anti-dsDNA response and altered the phenotype of the double negative T cells that are expanded in these mice. In examining for anatomic correlates of these immunologic changes, we found that the double negative T cells are localized within ectopic follicles around a central B cell patch and that these T cell-rich areas lack the T zone stromal protein ER-TR7 as well as other elements of a normal T zone microenvironment. SU5416 treatment disrupted these follicles and normalized the association between T zone microenvironmental elements and T cell-rich areas. Recent studies have shown a regulatory role for T zone stromal elements. Thus, our findings of the association of anti-dsDNA responses, double negative T cell phenotype, and altered lymphocyte microenvironment suggest the possibility that lymphocyte localization in ectopic follicles protects them from regulation by T zone stromal elements and functions to maintain autoimmune responses. Potentially, altering the lymphocyte microenvironment that is set up by the vascular-stromal compartment can be a means by which to control undesired autoimmune responses.

Show MeSH
Related in: MedlinePlus