Rabbit Anti-CCR7 monoclonal antibody, clone TS47-15

Innate and adaptive immunity regulate the inflammatory and erosive phenotypes observed in rheumatoid arthritis (RA) patients. Hence, identifying novel pathways that participate in different stages of RA pathology will provide valuable insights concerning the mechanistic behavior of different joint leukocytes and the strategy to restrain their activity. Recent findings have revealed that CCL21 poses as a risk factor for RA and expression of its receptor, CCR7, on circulating monocytes is representative of the patient's disease activity score. Expression of CCR7 was found to be the hallmark of RA synovial fluid (SF) M1 macrophages (M Phi s) and its levels were potentiated in response to M1 mediating factors and curtailed by M2 mediators in naive M Phi s. Intriguingly, although both CCR7 ligands, CCL19 and CCL21, are elevated in RA specimens, only CCL21 was predominately responsible for CCR7's pathological manifestation of RA. Unique subset of M Phi s differentiated in response to CCL21 stimulation, exhibited upregulation in Th17-polarizing monokines. Moreover, CCL21-activated monokines were capable of differentiating naive T cells into joint Th17 cells, which also partook in RA osteoclastogenesis. Finally, to conserve chronic inflammation, SF CCL21 amplified RA neovascularization directly and indirectly by promoting RA FLS and M Phi s to secrete proangiogenic factors, VEGF and IL-17. This review aims to shed light on the broad pathogenic impact of CCL21, linking immunostimulatory M Phi s with Th17 cells, while concurrently advancing RA bone destruction and neovascularization.

Despite the shared pattern of surface antigens, neoplastic cells in chronic lymphocytic leukemia (CLL) are highly heterogeneous in CD5 expression, a marker linked to a proliferative pool of neoplastic cells. To further characterize CD5(high)and CD5(low)neoplastic cells, we assessed the chemokine receptors (CCR5, CCR7, CCR10, CXCR3, CXCR4, CXCR5) and adhesion molecules (CD54, CD62L, CD49d) on the CD5(high)and CD5(low)subpopulations, defined by CD5/CD19 coexpression, in peripheral blood of CLL patients (n=60) subgrouped according to theIgHVmutational status (IgHV(mut),n=24;IgHV(unmut),n=36). CD5(high)subpopulation showed a high percentage of CXCR3 (P<0.001), CCR10 (P=0.001), and CD62L (P=0.031) and high levels of CXCR5 (P=0.005), CCR7 (P=0.013) compared to CD5(low)cells expressing high CXCR4 (P<0.001). ComparingIgHV(mut)andIgHV(unmut)patients, high levels of CXCR3 on CD5(high)and CD5(low)subpopulations were detected in theIgHV(mut)patients, with better discrimination in CD5(low)subpopulation. Levels of CXCR3 on CD5(low)subpopulation were associated with time to the next treatment, thus further confirming its prognostic value. Taken together, our analysis revealed higher CXCR3 expression on both CD5(high)and CD5(low)neoplastic cells inIgHV(mut)with a better prognosis compared toIgHV(unmut)patients. Contribution of CXCR3 to CLL pathophysiology and its suitability for prognostication and therapeutic exploitation deserves future investigations.