Background and purpose
Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immunomediated condition affecting the peripheral nervous system where probably macrophages are the ...primary effector cells for demyelination. Reactive oxygen species (ROS), catalyzed by the NOX family of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzymes, can induce peroxidation and are potentially injurious to myelin. Our aim was to assess the activity of NOX2, an isoform of NOX, in a series of CIDP patients and to analyze the effect of intravenous immunoglobulin (IVIg) on NOX2.
Methods
Thirty CIDP patients treated with IVIg and 30 control subjects were enrolled. To evaluate NOX2 activity, neutrophil and monocyte oxidative burst was measured directly in fresh whole blood using the Phagoburst™ assay, a fluorescence‐activated cell sorting method. The mean fluorescence intensity, emitted in response to different stimuli, leads to the production of ROS and corresponds to the percentage of oxidizing cells and their enzymatic activity.
Results
Mean fluorescence intensity values for granulocyte and monocyte burst in patients (mean 633.3, SD 191; mean 111.8, SD 28.5) were different from those measured in healthy controls (granulocytes, mean 436.6, SD 137.0, P = 0.0003; monocytes, mean 78.2, SD 17.3, P = 0.000001). Moreover, IVIg administration increased both granulocyte (P = 0.005) and monocyte (P = 0.0009) burst.
Conclusion
Our findings demonstrate that oxidative burst is significantly increased in CIDP patients and that treatment with IVIg enhances oxidative values, thus representing a possible IVIg therapeutic effect linked to a regulatory effect of ROS. Based on this, the development of treatments targeting the specific activation of NOX may be beneficial in autoimmune disorders.
CCL16 is a CC chemokine originally identified as a liver-expressed chemokine. Its expression has been detected in activated monocytes where it is up-regulated by stimulation with IL-10. This is in ...contrast with IL-10's inhibition of the expression of most chemokines. CCL16 is chemotactic for monocytes, lymphocyte and dendritic cells. We investigated whether CCL16 displays biological activities other than chemotaxis and whether IL-10 affects monocyte response to CCL16. We show that CCL16 induces the expression of CCL2 at the mRNA and protein level, but does not affect that of CCL5, CCL18 and proinflammatory cytokines. This effect was prevented by treatment with pertussis toxin and may thus be mediated by G-protein-coupled receptors. IL-10 markedly increased CCL2 production induced by CCL16, but suppressed that of CXCL8. It also enhanced the chemotactic response to CCL16. Addition of antibodies blocking CCR1, but not CCR8, prevented this enhanced chemotactic response and suggested that CCR1 is primarily involved. We propose that IL-10 modulates the effects of CCL16 on monocytes by increasing their CCR1-dependent response. The coordinated secretion of CCL16 and IL-10 may thus enhance monocyte infiltration.
T cells from HLA A2+ healthy donors were co-cultured with autologous dendritic cells (DC) loaded with apoptotic tumor cells expressing rat neu, and were induced to mature by tumor necrosis factor ...(TNF)α and interleukin (IL)-1β (mDCneu) or by the CCL16 chemokine (CCL16/mDCneu). Priming by CCL16/mDCneu induces a larger population of T cells that express cytoplasmatic interferon (IFN)γ, TNFα, perforin and granzyme B compared to those primed by mDCneu. T cells primed by CCL16/mDCneu release IFNγ in response to human HER-2+ cells and kill human HER-2+ target cells more efficiently than those primed by mDCneu. Our results show that both the loading of DC with xenogeneic rat neu and their maturation by CCL16 are two issues of critical importance for the elicitation of an effective response to human HER-2 in T cells from normal donors.
Immunolocalization of V1 vasopressin receptors in the rat kidney using anti-receptor antibodies. By using immunocytochemical techniques we have been able to localize the V1 vasopressin receptor in ...the rat kidney. Immunoblotting using an antiserum raised against an affinity-purified vasopressin receptor showed a 55,000 daltons protein band that has a molecular mass similar to that of the liver V1 vasopressin receptor, as demonstrated by cross-linking studies. Immunoblotting of the antibody showed a band of 55,000 daltons in A-10 cells, which contains the V1 subtype, whereas it did not stain LLC-PK1 cells, which possess the V2 subtype, showing that the antibody recognizes the V1 vasopressin receptor. The immunostaining of kidney sections with this antiserum showed a strong reaction of the connecting tubules and cortical and medullary collecting ducts. The immunostaining pattern of connecting tubule and collecting duct cells was different, that is, the former showed a staining of both the apical and basal plasma membrane but also in the cytoplasm, whereas the latter showed a strong reaction mainly in the basolateral membrane. Immunostaining of consecutive serial sections with an antiserum raised against tissue kallikrein, an enzyme present exclusively in connecting tubules, and with the anti-receptor serum allowed us to show, for the first time, the presence of the vasopressin receptor in the connecting tubule cells and their absence in intercalated cells, the other cell type present in connecting tubules. These findings support experiments carried in the eighties on the release of renal tissue kallikrein by AVP.
Within 33 weeks of life, all 10 mammary glands of virgin BALB/c mice transgenic for the transforming rat HER-2/neu oncogene under the mammary tumor virus promoter (BALB-neuT mice) progress from ...atypical hyperplasia to invasive palpable carcinoma. Repeated DNA vaccination with plasmids coding for the extracellular and transmembrane domain of the protein product of rat HER-2/neu (r-p185(neu)) delayed tumor onset and reduced tumor multiplicity, but this protection eventually declined, and few mice were tumor free at 1 year of age. Association of plasmid vaccination with administration of soluble mouse LAG-3 (lymphocyte activation gene-3/CD223) generated by fusing the extracellular domain of murine LAG-3 to a murine IgG2a Fc portion (mLAG-3Ig) elicited a stronger and sustained protection that kept 70% of 1-year-old mice tumor free. Moreover, this combined vaccination, which was performed when multiple in situ carcinomas were already evident, extended disease-free survival and reduced carcinoma multiplicity. Inhibition of carcinogenesis was associated with markedly reduced epithelial cell proliferation and r-p185(neu) expression, whereas the few remaining hyperplastic foci were heavily infiltrated by reactive leukocytes. A stronger and enduring r-p185(neu)-specific cytotoxicity, a sustained release of IFN-gamma and interleukin 4, and a marked expansion of both CD8(+)/CD11b(+)/CD28(+) effector and CD8(+)/CD11b(+)/CD28(-) memory effector T-cell populations were induced in immunized mice. This combined vaccination also elicited a quicker and higher antibody response to r-p185(neu), as well as an early antibody isotype switch. These data suggest that the appropriate costimulation provided by mLAG-3Ig enables DNA vaccination to establish an effective protection, probably by enhancing cross-presentation of the DNA coded antigen.
The huan CC chemokine CCL16, a liver‐expressed chemokine, enhances the killing activity of mouse peritoneal macrophages by triggering their expression of tumor necrosis factor α (TNF‐α) and Fas ...ligand. Macrophages also respond to CCL16 by enhancing their production of monocyte chemoattractant protein‐1, regulated on activation, normal T cells expressed and secreted chemokines, and interleukin (IL)‐1β, TNF‐α, and IL‐12. The effect of CCL16 is almost as strong as that of lipopolysaccharide and interferon‐γ, two of the best macrophage activators. Moreover, CCL16‐activated macrophages overexpress membrane CD80, CD86, and CD40 costimulatory molecules and extensively phagocytose tumor cell debris. On exposure to such debris, they activate a strong, tumor‐specific, cytolytic response in virgin T cells. Furthermore, cytolytic T cells generated in the presence of CCL16 display a higher cytotoxicity and activate caspase‐8 in tumor target cells. This ability to activate caspase‐8 depends on their overexpression of TNF‐α and Fas ligand induced by CCL16. These data reveal a new function for CCL16 in the immune‐response scenario. CCL16 significantly enhances the effector and the antigen‐presenting function of macrophages and augments T cell lytic activity.
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