The lymph node stromal laminin α5 shapes alloimmunity
Lushen Li, Marina W. Shirkey, Tianshu Zhang, Yanbao Xiong, Wenji Piao, Vikas Saxena, Christina Paluskievicz, Young Lee, Nicholas Toney, Benjamin M. Cerel, Qinshan Li, Thomas Simon, Kyle D. Smith, Keli L. Hippen, Bruce R. Blazar, Reza Abdi, Jonathan S. Bromberg
Lushen Li, Marina W. Shirkey, Tianshu Zhang, Yanbao Xiong, Wenji Piao, Vikas Saxena, Christina Paluskievicz, Young Lee, Nicholas Toney, Benjamin M. Cerel, Qinshan Li, Thomas Simon, Kyle D. Smith, Keli L. Hippen, Bruce R. Blazar, Reza Abdi, Jonathan S. Bromberg
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Research Article Immunology

The lymph node stromal laminin α5 shapes alloimmunity

Abstract

Lymph node stromal cells (LNSCs) regulate immunity through constructing lymphocyte niches. LNSC-produced laminin α5 (Lama5) regulates CD4+ T cells but the underlying mechanisms of its functions are poorly understood. Here we show that depleting Lama5 in LNSCs resulted in decreased Lama5 protein in the LN cortical ridge (CR) and around high endothelial venules (HEVs). Lama5 depletion affected LN structure with increased HEVs, upregulated chemokines, and cell adhesion molecules, and led to greater numbers of Tregs in the T cell zone. Mouse and human T cell transendothelial migration and T cell entry into LNs were suppressed by Lama5 through the receptors α6 integrin and α-dystroglycan. During immune responses and allograft transplantation, depleting Lama5 promoted antigen-specific CD4+ T cell entry into the CR through HEVs, suppressed T cell activation, and altered T cell differentiation to suppressive regulatory phenotypes. Enhanced allograft acceptance resulted from depleting Lama5 or blockade of T cell Lama5 receptors. Lama5 and Lama4/Lama5 ratios in allografts were associated with the rejection severity. Overall, our results demonstrated that stromal Lama5 regulated immune responses through altering LN structures and T cell behaviors. This study delineated a stromal Lama5–T cell receptor axis that can be targeted for immune tolerance modulation.

Authors

Lushen Li, Marina W. Shirkey, Tianshu Zhang, Yanbao Xiong, Wenji Piao, Vikas Saxena, Christina Paluskievicz, Young Lee, Nicholas Toney, Benjamin M. Cerel, Qinshan Li, Thomas Simon, Kyle D. Smith, Keli L. Hippen, Bruce R. Blazar, Reza Abdi, Jonathan S. Bromberg

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Figure 5

Lama5 inhibits CD4+ T cell and iTreg transendothelial migration via α6-integrin and αDG.

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Lama5 inhibits CD4+ T cell and iTreg transendothelial migration via α6-i...
(A) Schematic representation of transwell assay. Boyden chambers were coated with 30 μg laminin; BECs line MS-1 monolayers coated on inserts. T cells (2 × 105) were loaded into the upper chamber, and 500 ng/mL CCL21 was added to the bottom chamber. Percentage of cells that migrated to the bottom chamber was determined after 3 hours. (B) Percentage of migrated CD4+ T cells; anti–α6 integrin or anti-αDG pretreatment of T cells. (C) Migration of CD4+ T effector and memory cells, natural and induced Tregs, and CD8+ T cells. (D) CD4+ T cell migration across laminin 421 or/and laminin 521. (E and F) Migration efficiency of human CD4+ iTregs and T effector cells; anti–α6 integrin or anti-αDG pretreatment. n = 6 (B–F). (G) Schematic representation of T cell migration in laminar flow channels with shear force using BioFlux. Laminar flow channels were coated with 30 μg/mL laminin 411 and/or 511. BEC MS-1 cells were grown to confluence and 500 ng/mL CCL21 was passed through the laminar flow channels and incubated at 37°C for 6 hours. CD4+ T cells or iTregs were passed through the flow channels at 0.5 dynes/cm2. (H) Adherence of CD4+ T cells or iTregs imaged at 1-minute intervals for 30 minutes. (I) CD4+ T cells pretreated with anti–α6 integrin or anti-αDG. n = 3 (H and I). (J) Adherence of CD4+ T cells or CD8+ T cells after 3 minutes of cell perfusion over BEC layers in a flow device (n = 6). Data are presented as mean ± SEM from 3 independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001 by 1-way ANOVA with Tukey’s multiple-comparisons test.