Rabbit Anti-Human CCL21 (a.a. 24-134) Polyclonal antibody

Background: Neuroinflammation in the spinal cord is a pathological event in remifentanil-induced hyperalgesia (MD, but its underlying molecular mechanisms remain unclear. Recent studies recapitulate the significance of the intracellular protease caspase-6 in the release of inflammatory mediators and synaptic plasticity in pathologic pain. Also, chemokine CCL21 is involved in microglia activation and nociceptive transduction. This study examined whether spinal caspase-6 is associated with RIH via CCL21 and its receptor CXCR3. Methods: The acute exposure to remifentanil (1 mu g kg(-1)min(-1) for 60 min) was used to establish RIH, verified by assessment of mechanical paw withdrawal threshold and thermal paw withdrawal latency. The caspase-6 inhibitor, a neutralizing antibody against CCL21 (anti-CCL21), a selective CXCR3 antagonist NBI-74330, recombinant caspase-6 and CCL21 were used for the investigation of pathogenesis as well as the prevention of hyperalgesia. The expression of caspase-6, CCL21 and CXCR3 was also evaluated by RT-qPCR and Western blot. Results: This study discovered mechanical allodynia and thermal hyperalgesia along with the increase in the expression of spinal caspase-6 and CCL21/CXCR3 after remifentanil exposure. Central caspase-6 inhibition prevented behavioral RIH and spinal up-regulation of CCL21/CXCR3 level. Intrathecal anti-CCL21 injection reduced RIH and spinal expression of CXCR3. The delivery of recombinant caspase-6 facilitated acute nociceptive hypersensitivity and increased spinal CXCR3 release in naive rats, reversing by co-application of antiCCL21. Also, NBI-74330 attenuated RIH and exogenous CCL21-caused acute pain behaviors. Conclusion: This study highlighted that spinal caspase-6-mediated up-regulation of CCL21/CXCR3 is vital in the pathogenesis of RIH in rats.

Background. Costimulatory blockade with anti-CD40L monoclonal antibody (mAb) plus donor-specific splenocyte transfusion (DST) induces alloantigen-specific tolerance. We previously showed that lymphotoxin signaling in the fibroblastic reticular cell (FRC) stromal subset was required for proper lymph node structure and function during tolerization in murine cardiac transplantation. Here we focused on FRC functions and hypothesized that DST and anti-CD40L mAb-modulated FRC interactions with CD4(+) Tcells in mice. Methods. Mice were immunized or tolerized by DST or DST plus anti-CD40L mAb. Fibroblastic reticular cells were flow-sorted at different timepoints for characterization and in vitro proliferation and activation assays. Results. Fibroblastic reticular cells responded rapidly to DST by transcribing inflammatory cytokine and chemokine messenger RNAs, such as CXCL2, CXCL9, CXCL10, and CCL21. Conversely, anti-CD40L mAb inhibited FRC inflammatory responses. CD40 was expressed on FRC and agonistic anti-CD40 mAb activated FRC, which supported CD4(+) T-cell proliferation, whereas unstimulated FRC did not. Anti-CD3 mAb-activated CD4(+) T cells induced inflammatory cytokine and chemokine expressions by FRC, which were inhibited by anti-CD40L mAb. Thus, FRC phenotype was altered by interaction with CD4(+) T cells through CD40-CD40L, and activated FRC interacted directly with CD4(+) T cells to support T cell activation and proliferation in vitro. Conclusions. Taken together, these results demonstrated that CD40 on FRC facilitated bidirectional communication between FRC and CD4(+) T cells via CD40-CD40L, thereby altering FRC gene expression of immune regulatory molecules. Because blockade of CD40-CD40L interactions results in tolerance in mice, identification of FRC-Tcell interactions provides a new research target for tolerance induction.