[A study on the roles of CD86 in antigen-induced eosinophil infiltration into airways and airway hyperresponsiveness]

OBJECTIVE

To explore the effect of CD86 on antigen-induced eosinophil infiltration into the airways and airway hyperresponsiveness in sensitized mice, and further elucidate the role of CD86 in the pathogenesis of bronchial asthma.

METHODS

Female BALB/c mice (n = 8 for each group) were sensitized and challenged with ovalbumin to induce airway eosinophilia and airway hyperresponsiveness. Airway responsiveness was espressed by the provocative concentration of acetylcholine causing 50% increase in respiratory resistance (PC50). Effect of anti-CD86 monoclonal antibody (mAb) on antigen-induced changes of eosinophil numbers in brochoalveolar lavage fluid (BALF) and airway reactivity was observed. CD86 expression on BALF cells was detected by flow cytometry and concentrations of interleukin-4 and interleukin-5 in homogenized supernatant of lung tissue were determined by ELISA.

RESULTS

In sensitized mice challenged with ovalbumin 20 minutes once a day for 6 days, the number of BALF eosinophils was (9.2 +/- 1.5) x 10(8)/L. However, no eosinophil could be found in the BALF from mice without ovalbumin sensitization and challenge. Also, ovalbumin treatment led to PC50 value decrease from (0.66 +/- 0.13) g/L to (0.17 +/- 0.07) g/L (P < 0.01). CD86 expression on BALF cells from ovalbumin sensitized- and challenged-mice (36.4 +/- 6.2) was much higher than that from control mice (12.3 +/- 3.6, P < 0.01). In mice treated with intravenous injection of anti-CD86 mAb before each challenge, BALF eosinophils decreased by 67% (P < 0.01), and PC50 value increased by 69% (P < 0.01). Our results showed that anti-CD86 mAb prevented antigen-induced airway eosinophilia and airway hyperresponsiveness accompanied by a decrement of levels of both interleukin-4 and interleukin-5 in lung tissue.

CONCLUSIONS

Anti-CD86 mAb is able to inhibit antigen-induced airway eosinophilia and to ameliorate airway hyperresponsiveness, possibly by inhibiting production of interleukin-4 and interleukin-5. These data suggested that the blockade of airway antigen-presenting cells' functions couid be of value in treatment of human asthma.

Chemokine and chemokine receptor interactions provide a mechanism for selective T cell recruitment to specific liver compartments within hepatitis C-infected liver

The role played by chemokines in regulating the selective recruitment of lymphocytes to different tissue compartments in disease is poorly characterized. In hepatitis C infection, inflammation confined to portal areas is associated with a less aggressive course, whereas T cell infiltration of the liver parenchyma is associated with progressive liver injury and cirrhosis. We propose a mechanism to explain how lymphocytes are recruited to hepatic lobules during bursts of necroinflammatory activity in chronic hepatitis C infection. We report here that lymphocytes infiltrating hepatitis C-infected liver express high levels of the chemokine receptors CCR5 and CXCR3. However, whereas the CCR5 ligands macrophage inflammatory protein-1alpha and -1beta were largely confined to vessels within portal tracts, the CXCR3 ligands IFN-inducible protein-10 and monokine-induced by IFN-gamma were selectively up-regulated on sinusoidal endothelium. In vitro, human hepatic sinusoidal endothelial cells secreted IFN-inducible protein-10 and monokine-induced by IFN-gamma in response to stimulation with IFN-gamma in combination with either IL-1 or TNF-alpha. This suggests that intrahepatic Th1 cytokines drive the increased expression of IFN-inducible protein-10 and monokine-induced by IFN-gamma and thereby promote the continuing recruitment of CXCR3-expressing T cells into the hepatic lobule in chronic hepatitis C infection.

Competitive repopulation of retrovirally transduced haemopoietic stem cells

Gene transfer into haemopoietic stem cells (HSC) may be useful in gene therapy for a variety of inherited and acquired human diseases. Cell division is required for retroviral transduction, and cytokine stimulation is often used to increase mitosis of quiescent HSC. Exposure to cytokines has been shown to have an unfavourable effect on the engraftment of these cells when competed with unmanipulated HSC. We now show that a similar engraftment defect is present when HSC are manipulated and transduced with the human multiple drug resistance (MDR) gene. The extent of the unfavourable competition depended on the relative numbers of cytokine-treated and fresh cells when the two populations of cells were administered simultaneously into marrow-ablated isogenic mice. When the manipulated transduced cells were given 2 or 4 d before the unmanipulated cells there was a much greater engraftment of the manipulated cells. The data suggested that the manipulated cells were at a relative disadvantage for marrow engraftment as compared to fresh cells, presumably due to the more efficient homing and engraftment properties of these latter unmanipulated cells. However, the manipulated cells had no intrinsic inability to engraft when they were the predominant donor cell population. In all cases the percent of MDR transduced cells in the engrafting manipulated cells remained relatively constant at about 25-30%. These results have implications for the use of manipulated transduced stem cells in gene therapy, suggesting that administering them before adding fresh cells can overcome their engraftment defect.

Involvement of receptor aggregation and reactive oxygen species in osmotic stress-induced Syk activation in B cells

Syk has been shown to be activated by osmotic stress, however, the mechanisms involved are largely unknown. In this study, we demonstrated that cell shrinkage, rather than osmolarity, was responsible for osmotic stress-induced Syk activation. Osmotic stress-induced Syk activation depended partly upon aggregation of surface receptors. Moreover, intracellular reactive oxygen species were involved in mediating osmotic stress-induced Syk activation, with osmotic stress-induced Syk activation being inhibited by the pretreatment of cells with N-acetyl-cysteine and reduced glutathione. When cells were treated with the combination of sodium chloride and hydrogen peroxide, there was a synergistic activation of Syk. In conclusion, osmotic stress-induced Syk activation required suramin-inhibitable surface receptor aggregation and accumulation of intracellular reactive oxygen species.

The chemokine receptor CCR4 in vascular recognition by cutaneous but not intestinal memory T cells

Lymphocytes that are responsible for regional (tissue-specific) immunity home from the blood to the intestines, inflamed skin or other sites through a multistep process involving recognition of vascular endothelial cells and extravasation. Chemoattractant cytokine molecules known as chemokines regulate this lymphocyte traffic, in part by triggering arrest (stopping) of lymphocytes rolling on endothelium. Here we show that many systemic memory T cells in blood carry the chemokine receptor CCR4 and therefore respond to its ligands, the chemokines TARC and MDC. These cells include essentially all skin-homing cells expressing the cutaneous lymphocyte antigen and a subset of other systemic memory lymphocytes; however, intestinal (alpha4beta7+) memory and naive T cells respond poorly. Immunohistochemistry reveals anti-TARC reactivity of venules and infiltration of many CCR4+ lymphocytes in chronically inflamed skin, but not in the gastrointestinal lamina propria. Moreover, TARC induces integrin-dependent adhesion of skin (but not intestinal) memory T cells to the cell-adhesion molecule ICAM-1, and causes their rapid arrest under physiological flow. Our results suggest that CCR4 and TARC are important in the recognition of skin vasculature by circulating T cells and in directing lymphocytes that are involved in systemic as opposed to intestinal immunity to their target tissues.

Expression and function of CXC and CC chemokines in human malignant liver tumors: a role for human monokine induced by gamma-interferon in lymphocyte recruitment to hepatocellular carcinoma

Chemotactic cytokines (chemokines) play an important role in the recruitment of lymphocytes to tissue by regulating cellular adhesion and transendothelial migration. This study examined the expression and function of CXC (human monokine induced by gamma-interferon [HuMig], interleukin-8 [IL-8], and interferon-inducible protein-10 [IP-10]) and CC (macrophage inflammatory protein-1alpha [MIP-1alpha], MIP-1beta, regulated upon activation normal T lymphocyte expressed and secreted (RANTES), and macrophage chemoattractant protein-1 [MCP-1]) chemokines and their respective receptors on lymphocytes infiltrating human liver tumors. Chemokine and chemokine receptor expression was assessed by immunohistochemistry, flow cytometry, in situ hybridization and ribonuclease (RNAse) protection assays and function by in vitro chemotaxis of tumor-derived lymphocytes to purified chemokines and to HepG2 tumor cell culture supernatants. Tumor-derived lymphocytes showed strong chemotactic responses to both CC and CXC chemokines in vitro and expressed high levels of CXCR3 (HuMig and IP-10 receptor) and CCR5 (RANTES, MIP-1alpha, and MIP-1beta receptor). Expansion of tumor-derived lymphocytes in recombinant IL-2 increased expression of CXCR3. The corresponding chemokines were detected on vascular endothelium (HuMig, IL-8, MIP-1alpha, and MIP-1beta) and sinusoidal endothelium (HuMig, MIP-1alpha, MIP-1beta) in hepatocellular carcinoma. In vitro, HepG2 cells secreted functional chemotactic factors for tumor-derived lymphocytes that could be inhibited using anti-CCR5 or anti-CXCR3 monoclonal antibodies (MoAbs). Thus, lymphocytes infiltrating human liver tumors express receptors for and respond to both CXC and CC chemokines. The relevant chemokine ligands are expressed in hepatocellular carcinoma (HCC), particularly HuMig, which was strongly expressed by tumor endothelium, suggesting that they play a role in lymphocyte recruitment to these tumors in vivo. The ability of HepG2 cells to secrete lymphocyte chemotactic factors in vitro suggests that the tumor contributes to lymphocyte recruitment in vivo.

Switch in chemokine receptor expression upon TCR stimulation reveals novel homing potential for recently activated T cells

When naive T lymphocytes are activated and differentiate into memory/effector cells, they down-regulate receptors for constitutive chemokines such as CXCR4 and CCR7 and acquire receptors for inflammatory chemokines such as CCR3, CCR5 and CXCR3, depending on the Th1/Th2 polarization. This switch in chemokine receptor usage leads to the acquisition of the capacity to migrate into inflamed tissues. Using RNase protection assays, staining with specific antibodies, and response to recombinant chemokines, we now show that following TCR stimulation, memory/effector T cells undergo a further and transient switch in receptor expression. CCR1, CCR2, CCR3, CCR5, CCR6 and CXCR3 are down-regulated within 6 h, while CCR7, CCR4, CCR8 and CXCR5 are up-regulated for 2 to 3 days. Up-regulation of CCR7 following TCR stimulation was observed also among resting peripheral blood T cells and required neither co-stimulation nor exogenous IL-2. On the other hand IL-2 down-regulated CXCR5, up-regulated CCR8 and facilitated the recovery of CCR3 and CCR5. Upon TCR stimulation, Th1 and Th2 cells produced comparable sets of chemokines, including RANTES, macrophage inflammatory protein-1beta, I-309, IL-8 and macrophage-derived chemokine, which may modulate surface chemokine receptors and contribute to cell recruitment at sites of antigenic recognition. Altogether these results show that following TCR stimulation effector/memory T cells transiently acquire responsiveness to constitutive chemokines. As a result, T cells that are activated in tissues may either recirculate to draining lymph nodes or migrate to nearby sites of organized ectopic lymphoid tissues.

[Survey on traditional medicinal resources of Uncaria distributed in China]

OBJECTIVE

To make clear the botanical origin of medicinal Uncaria distributed in China and the situation of its use in folk medicines.

METHODS

Collecting data and making on-the-spot investigation.

RESULTS

There are thirteen medicinal plants which belong to Uncaria genus, and ten of them are commercially available. A clear idea was obtained of their geographical distribution, distribution features and practical experiences in folk application.

CONCLUSION

This investigation is helpful in further researching and exploring the resources of Uncaria for medical use, as well as provides a scientific basis for production, management and safe use of crude drugs.

Expression of specific chemokines and chemokine receptors in the central nervous system of multiple sclerosis patients

Chemokines direct tissue invasion by specific leukocyte populations. Thus, chemokines may play a role in multiple sclerosis (MS), an idiopathic disorder in which the central nervous system (CNS) inflammatory reaction is largely restricted to mononuclear phagocytes and T cells. We asked whether specific chemokines were expressed in the CNS during acute demyelinating events by analyzing cerebrospinal fluid (CSF), whose composition reflects the CNS extracellular space. During MS attacks, we found elevated CSF levels of three chemokines that act toward T cells and mononuclear phagocytes: interferon-gamma-inducible protein of 10 kDa (IP-10); monokine induced by interferon-gamma (Mig); and regulated on activation, normal T-cell expressed and secreted (RANTES). We then investigated whether specific chemokine receptors were expressed by infiltrating cells in demyelinating MS brain lesions and in CSF. CXCR3, an IP-10/Mig receptor, was expressed on lymphocytic cells in virtually every perivascular inflammatory infiltrate in active MS lesions. CCR5, a RANTES receptor, was detected on lymphocytic cells, macrophages, and microglia in actively demyelinating MS brain lesions. Compared with circulating T cells, CSF T cells were significantly enriched for cells expressing CXCR3 or CCR5. Our results imply pathogenic roles for specific chemokine-chemokine receptor interactions in MS and suggest new molecular targets for therapeutic intervention.

[Morphological cure of cerebral arteriovenous malformations by endovascular therapeutics]

OBJECTIVE

To sum up the clinical characteristics and typical manifestation by analysing clinical materials from total embolized cerebral arteriovenous malformations (AVM) via endovascular embolization.

METHODS

We reviewed clinical and image materials of 50 patients whose cerebral AVM were embolized entirely and found the cerebral AVM morphological cure by endovascular embolization after studying the size, position, artery supply, therapeutics and follow-up.

RESULTS

50 patients with cerebral AVM were embolized by endovascular therapy, accounting for 17% of all patients. Malformation lesions were medium or small type, with a diameter less than 3 cm, 95% of them were located in the tentorium superior. Terminal end blood supply was common to AVM and especially medium cerebral artery (MCA) or its branches. 97% of the patients were graded III or below by spectzler grading system. 70% of them had a history of intracranial hemorrhage and were cured by one therapy.

CONCLUSIONS

It is a reliable and feasible method for morphological cure in cerebral AVM via endovascular therapeutics only, but case selection is important, that is, medium or small AVM with single branch terminal end blood supply in the tentorium superior.

[HBsAg expression, anti-HBs induction and pathological observation in the mice inoculated with DNA vaccine against hepatitis B]

OBJECTIVE

To study if special humoral immunological response can be induced by DNA vaccine against Hepatitis B (NV-HB/s) and its mechanism.

METHODS

The Balb/C mice inoculated with NV-HB/s by intramuscular injection were detected for HBsAg(the expressed product of NV-HB/s) by ABC immunohistochemistry or ELISA, and for anti-HBs by ELISA and also performed the routine pathological examination.

RESULTS

After inoculated with NV-HB/s, HBsAg could be detected from mice muscle tissue samples of injected sites one week later and almost kept positive(75% and even more) up to 6th month, but was undetectable from all the serum samples during this period; anti-HBs could be detected from serum samples of some mice two weeks later and of all the mice detected one month later, it still kept positive at 6th month while the mice were sacrificed. Under microscope, only non-specific inflammation was found in the muscle tissues of injected sites and could completely recover within 4 weeks, no matter whether the mice were inoculated with NV-HBs, or with traditional HB vaccine derived from blood, or even with PBS as control.

CONCLUSION

DNA vaccine against Hepatitis B (NV-HB/s) can successfully express HBsAg in the muscle tissue of mice by intramuscular inoculation and subsequently induce anti-HBs in vitro.

[Nested polymerase chain reaction in detecting Mycobacterium tuberculosis DNA in bioptic tissue from patients with endobronchial tuberculosis]

OBJECTIVE

To evaluate the nested polymerase chain reaction (NPCR) technique in diagnosing endobronchial tuberculosis.

METHODS

NPCR method was used to detect Mycobacterium tuberculosis DNA in bioptic tissue from 67 patients with endobronchial tuberculosis, and the results were compared with pathologic examination, brushing smear, sputum smear and culture for Mycobacterium tuberculosis after bronchoscopy. The controls were 43 patients with lung cancer.

RESULTS

The positive rates of detecting Mycobacterium tuberculosis were 13%, 19%, 22%, 15% and 76% respectively by pathologic examination, brushing smear, sputum smear, culture after bronchoscopy and NPCR methods. Significant differences were found between NPCR and the other 4 methods (all Ps < 0.01). No positive result for Mycobacterium tuberculosis was found in 43 controls by NPCR.

CONCLUSIONS

NPCR is a useful method for diagnosing patients with endobronchial tuberculosis, especially for those with normal demonstration in X-ray chest film, negative sputum and nonspecific pathologic changes in endobronchial biopsy.

[Detection of NV-HB/s DNA and c-myc mRNA in mice inoculated with hepatitis B nucleic acid vaccine--NV-HB/s]

OBJECTIVE

To explore the persistence period of plasmid in mice muscles injected with NV-HB/s and the possible influence on oncogene C-myc.

METHODS

Anti-HBs was detected by ELISA; NV-HB/s was detected by In-situ and Southern-blot hybridization separately; C-myc mRNA was detected by In-situ hybridization.

RESULTS

All mice injected with NV-HB/s were positive of anti-HBs after 1 month of immunization; NV-HB/s was negative when detected by In-situ hybridization; By Southern-blot hybridization, the positive rates of NV-HB/s were decreasing from 100% in 2 months to 25% after 6 months of inoculation.

CONCLUSIONS

NV-HB/s would be disintegrated little by little after injected into mouse muscles; no C-myc activation was observed in 6 months after NV-HB/s inoculation.

Multiple activation steps of the N-formyl peptide receptor

The human N-formyl peptide receptor (FPR) is representative of a growing family of G protein-coupled receptors (GPCR) that respond to chemokines and chemoattractants. Despite the importance of this receptor class to immune function, relatively little is known about the molecular mechanisms involved in their activation. To reveal steps required for the activation of GPCR receptors, we utilized mutants of the FPR which have previously been shown to be incapable of binding and activating G proteins. For this study, the FPR mutants were expressed in human myeloid U937 cells and characterized for functions in addition to G protein coupling, such as receptor phosphorylation and ligand-induced receptor internalization. The results demonstrated that one of the mutants, R123G, though being unable to activate G protein, was capable of undergoing ligand-induced phosphorylation as well as internalization. Receptor internalization was monitored by following the fate of the ligand as well as by directly monitoring the fate of the receptor. The results with the R123G mutant were in contrast to those obtained for mutants D71A and R309G/E310A/R311G which, though being expressed at the cell surface and binding ligand, were incapable of being phosphorylated or internalized upon agonist stimulation. These results suggest that following ligand binding at least two "steps" are required for full activation of the wild-type FPR. That these observations may be of more general importance in GPCR-mediated signaling is suggested by the highly conserved nature of the mutants studied: D71, R123, and the site represented by amino acids 309-311 are very highly conserved throughout the entire superfamily of G protein-coupled receptors. Models of receptor activation based on the observed results are discussed.

Interleukin-8 receptor modulates IgE production and B-cell expansion and trafficking in allergen-induced pulmonary inflammation

We examined the role of the interleukin-8 (IL-8) receptor in a murine model of allergen-induced pulmonary inflammation using mice with a targeted deletion of the murine IL-8 receptor homologue (IL-8r-/-). Wild-type (Wt) and IL-8r-/- mice were systemically immunized to ovalbumin (OVA) and were exposed with either single or multiple challenge of aerosolized phosphate-buffered saline (OVA/PBS) or OVA (OVA/OVA). Analysis of cells recovered from bronchoalveolar lavage (BAL) revealed a diminished recruitment of neutrophils to the airway lumen after single challenge in IL-8r-/- mice compared with Wt mice, whereas multiply challenged IL-8r-/- mice had increased B cells and fewer neutrophils compared with Wt mice. Both Wt and IL-8r-/- OVA/OVA mice recruited similar numbers of eosinophils to the BAL fluid and exhibited comparable degrees of pulmonary inflammation histologically. Both total and OVA-specific IgE levels were greater in multiply challenged IL-8r-/- OVA/OVA mice than in Wt mice. Both the IL-8r-/- OVA/OVA and OVA/PBS mice were significantly less responsive to methacholine than their respective Wt groups, but both Wt and IL-8r mice showed similar degrees of enhancement after multiple allergen challenge. The data demonstrate that the IL-8r modulates IgE production, airway responsiveness, and the composition of the cells (B cells and neutrophils) recruited to the airway lumen in response to antigen.

[Electroanalytical characteristics of ofloxacin in micellar solution]

In a pH 6.30 buffer solution containing 0.001% Tween-80, ofloxacin (OFX) gives a sensitive polarographic wave at -1.46 V (vs SCE), which can be used for the determination of OFX down to 10(-8) mol.L-1. The linear range is from 1.39 x 10(-7) to 1.39 x 10(-5) mol.L-1. The proposed method was applied to determination of OFX in urine and serum samples with relative standard deviation less than 7.0%.

Involvement of the IP-10 chemokine in sarcoid granulomatous reactions

The accumulation of T cells and monocytes at sites of ongoing inflammation represents the earliest step in the series of events that lead to granuloma formation in sarcoidosis. In this study, we evaluated the pulmonary production of IFN-inducible protein 10 (IP-10), a CXC chemokine that stimulates the directional migration of activated T cells. Striking levels of IP-10 were demonstrated in the bronchoalveolar lavage (BAL) fluid of 24 patients with pulmonary sarcoidosis and lymphocytic alveolitis, as compared with patients with inactive disease or control subjects. A positive correlation was demonstrated between IP-10 levels and the number of sarcoid CD45R0+/CD4+ cells in the BAL. Immunochemistry, performed with an anti-human IP-10 polyclonal Ab in lymph nodes displaying prominent sarcoid granulomas, showed that cells bearing IP-10 were mainly epithelioid cells and CD68+ macrophages located inside granulomatous areas. Macrophages recovered from the BAL of sarcoid patients stained positive for IP-10 protein. Furthermore, alveolar macrophages isolated from sarcoid patients with T cell alveolitis and cultured for 24 h in presence of IFN-gamma secreted definite levels of IP-10 capable of inducing T cell chemiotaxis. Interestingly, alveolar lymphocytes recovered from patients with active sarcoidosis were CD4+ T cells expressing Th1 cytokines (IL-2 and IFN-gamma) and high levels of CXCR3. Taken together, these data suggest the potential role of IP-10 in regulating the migration and activation of T cells toward sites of sarcoid inflammatory process and the consequent granuloma formation.

The bipartite geminivirus coat protein aids BR1 function in viral movement by affecting the accumulation of viral single-stranded DNA

The movement of bipartite geminiviruses such as squash leaf curl virus (SqLCV) requires the cooperative interaction of two essential virus-encoded movement proteins, BR1 and BL1. While the viral coat protein AR1 is not essential for systemic infection, genetic studies demonstrate that its presence masks the defective phenotype of certain BR1 missense mutants, thus suggesting that coat protein does interact with the viral movement pathway. To further examine the mechanism of this interaction, we have constructed alanine-scanning mutants of AR1 and studied them for the ability to mask the infectivity defects of appropriate BR1 mutants, for the ability to target to the nucleus and to bind viral single-stranded DNA (ssDNA) and multimerize, and for effects on the accumulation of replicated viral ssDNA. We identified a specific region of AR1 required for masking of appropriate BR1 mutants and showed that this same region of AR1 was also important for ssDNA binding and the accumulation of viral replicated ssDNA. This region of AR1 also overlapped that involved in multimerization of the coat protein. We also found that the accumulation in protoplasts of single-stranded forms of a recombinant plasmid that included the SqLCV replication origin but was too large to be encapsidated was dependent on the presence of AR1 but did not appear to require encapsidation. These findings extend our model for SqLCV movement, demonstrating that coat protein affects viral movement through its ability to induce the accumulation of replicated viral ssDNA genomes. They further suggested that encapsidation was not required for the AR1-dependent accumulation of viral ssDNA.

The alpha-chemokine, stromal cell-derived factor-1alpha, binds to the transmembrane G-protein-coupled CXCR-4 receptor and activates multiple signal transduction pathways

The alpha-chemokine stromal cell-derived factor (SDF)-1alpha binds to the seven transmembrane G-protein-coupled CXCR-4 receptor and acts to modulate cell migration and proliferation. The signaling pathways that mediate the effects of SDF-1alpha are not well characterized. We studied events following SDF-1alpha binding to CXCR-4 in a model murine pre-B cell line transfected with human CXCR-4. There was enhanced tyrosine phosphorylation and association of components of focal adhesion complexes such as the related adhesion focal tyrosine kinase, paxillin, and Crk. We also observed activation of phosphatidylinositol 3-kinase. Wortmannin, a selective inhibitor of phosphatidylinositol 3-kinase, partially inhibited the SDF-1alpha-induced migration and tyrosine phosphorylation of paxillin. SDF-1alpha treatment selectively activated p44/42 mitogen-activated protein kinase (Erk 1 and Erk 2) and its upstream kinase mitogen-activated protein kinase kinase but not p38 mitogen-activated protein kinase, c-Jun amino-terminal kinase or mitogen activated protein kinase kinase. We also observed that SDF-1alpha treatment increased NF-kappaB activity in nuclear extracts from the CXCR-4 transfectants. Taken together, these studies revealed that SDF-1alpha activates distinct signaling pathways that may mediate cell growth, migration, and transcriptional activation.

Rapid and coordinated switch in chemokine receptor expression during dendritic cell maturation

Dendritic cells (DC) migrate into inflamed peripheral tissues where they capture antigens and, following maturation, to lymph nodes where they stimulate T cells. To gain insight into this process we compared chemokine receptor expression in immature and mature DC. Immature DC expressed CCR1, CCR2, CCR5 and CXCR1 and responded to their respective ligands, which are chemokines produced at inflammatory sites. Following stimulation with LPS or TNF-alpha maturing DC expressed high levels of CCR7 mRNA and acquired responsiveness to the CCR7 ligand EBI1 ligand chemokine (ELC), a chemokine produced in lymphoid organs. Maturation also resulted in up-regulation of CXCR4 and down-regulation of CXCR1 mRNA, while CCR1 and CCR5 mRNA were only marginally affected for up to 40 h. However, CCR1 and CCR5 were lost from the cell surface within 3 h, due to receptor down-regulation mediated by chemokines produced by maturing DC. A complete down-regulation of CCR1 and CCR5 mRNA was observed only after stimulation with CD40 ligand of DC induced to mature by LPS treatment. These different patterns of chemokine receptors are consistent with "inflammatory" and "primary response" phases of DC function.

[Clinical value of a rapid immunochromatographic assay in diagnosis and differential diagnosis of bone and joint tuberculosis]

OBJECTIVE

To evaluate the clinical value of a rapid immunochromatographic assay in diagnosis and differential diagnosis of bone and joint tuberculosis.

METHOD

Antibodies in sera from 75 patients with active bone and joint tuberculosis, 69 patients with non-tuberculous bone and joint diseases and 72 healthy individuals were detected by the rapid immunochromatographic assay using ICT-TB kit.

RESULT

The positive rate was found to be 80% in the patients with active bone and joint tuberculosis, while 90% in the group with spinal tuberculosis, 53% in the extra-spinal articular tuberculosis. The false positive rates were 4% and 3% respectively in those with other bone and joint diseases and healthy individuals.

CONCLUSION

The assay is a rapid, sensitive and specific supplementary tool for the diagnosis of the bone and joint tuberculosis.

A deficiency in Syk enhances ceramide-induced apoptosis in DT40 lymphoma B cells

Syk deficiency significantly enhanced ceramide-induced apoptosis. Ectopic expression of wild-type or kinase-inactive Syk rendered Syk-negative cells resistant to ceramide-induced apoptosis. Furthermore, ceramide could not activate Syk, indicating that Syk protected DT40 cells from ceramide-induced apoptosis, via a mechanism independent of its activity. In addition, a deficiency in Lyn also resulted in the cells becoming susceptible to ceramide-induced apoptosis. However, no difference of Ara-C-induced apoptosis between wild-type and mutant cells was observed. c-Jun N-terminal kinases appeared not to be important in mediating the enhanced apoptosis, as they were still activated in mutant cells following ceramide treatment.

Differential regulation of oxidative and osmotic stress induced Syk activation by both autophosphorylation and SH2 domains

Syk, a nonreceptor protein-tyrosine kinase, is activated by both oxidative and osmotic stress and plays different roles in the transduction of stress signals. In this study, the regulation of oxidative and osmotic stress induced Syk activation was investigated utilizing Syk-negative DT40 cells, expressing various Syk mutants. Phosphorylation of Y518Y519 was demonstrated to be required for both oxidative and osmotic stress induced Syk activation. Syk activation by these two types of stress stimuli was a combination of both autophosphorylation and the activities of additional tyrosine kinases. Oxidative stress induced Syk tyrosine phosphorylation was almost completely attributed to autophosphorylation, whereas other tyrosine kinases were largely responsible for osmotic stress induced Syk tyrosine phosphorylation. Moreover, the Src homology 2 (SH2) domains of Syk differentially regulated Syk activation. Both mSH2(N) Syk and mSH2(C) Syk, in which the phosphotyrosine-dependent binding motif within the SH2 domains contained point mutations, showed a significantly higher activity than that observed in wild-type Syk, following osmotic stress treatment. In comparison, in response to oxidative stress, only mSH2(N) Syk demonstrated a stronger activation than wild-type Syk. Therefore, differential activation and regulation of Syk may give an insight into the distinctive functions of Syk in oxidative and osmotic stress signaling.

[A survey on botanical origins of drug tiannanxing produced in Sichuan]

According to the investigation and identification of botanical origins of 7 species and 1 variety of the traditional Chinese drug Tiannanxing produced in Sichuan, it has been found out that the main species available on the market are Arisaema erubescens and A. heterophyllum, while A. asperatum, A. wilsonii and A. fargesil come second. A key for their identification is presented in this paper.

The chemokine receptors CXCR3 and CCR5 mark subsets of T cells associated with certain inflammatory reactions

T cells infiltrating inflammatory sites are usually of the activated/memory type. The precise mechanism for the positioning of these cells within tissues is unclear. Adhesion molecules certainly play a role; however, the intricate control of cell migration appears to be mediated by numerous chemokines and their receptors. Particularly important chemokines for activated/memory T cells are the CXCR3 ligands IP-10 and Mig and the CCR5 ligands RANTES, macrophage inflammatory protein-1alpha, and macrophage inflammatory protein-1beta. We raised anti-CXCR3 mAbs and were able to detect high levels of CXCR3 expression on activated T cells. Surprisingly, a proportion of circulating blood T cells, B cells, and natural killer cells also expressed CXCR3. CCR5 showed a similar expression pattern as CXCR3, but was expressed on fewer circulating T cells. Blood T cells expressing CXCR3 (and CCR5) were mostly CD45RO+, and generally expressed high levels of beta1 integrins. This phenotype resembled that of T cells infiltrating inflammatory lesions. Immunostaining of T cells in rheumatoid arthritis synovial fluid confirmed that virtually all such T cells expressed CXCR3 and approximately 80% expressed CCR5, representing high enrichment over levels of CXCR3+ and CCR5+ T cells in blood, 35 and 15%, respectively. Analysis by immunohistochemistry of various inflamed tissues gave comparable findings in that virtually all T cells within the lesions expressed CXCR3, particularly in perivascular regions, whereas far fewer T cells within normal lymph nodes expressed CXCR3 or CCR5. These results demonstrate that the chemokine receptor CXCR3 and CCR5 are markers for T cells associated with certain inflammatory reactions, particularly TH-1 type reactions. Moreover, CXCR3 and CCR5 appear to identify subsets of T cells in blood with a predilection for homing to these sites.

[Effects of heat, noise, and their combination on plasma atrial natriuretic peptides, cardiodilatin, endogenous digitalis like substance, angiotensin II and endothelin in rats]

Plasma contents of atrial natriuretic peptides (ANP), cardiodilatin (CDD), endogenous digitalis like substance (EDLS), angiotensin II (A II) and endothelin (ET) were determined in rats following exposure to high temperature, noise and a combination of the two. It was found that plasma content of ANP after heat exposure decreased significantly, CDD and A II content after heat or noise exposure increased obviously, ET content decreased significantly after exposure to combined factors. ANP and CDD have the same physiological function and changes. ANP, CDD and A II observed in the present study were considered to be compensatory responses. It is harmful if exposure to high temperature or noise lasts for a long time.

Evidence of increased endogenous carbon monoxide production in newborn rat endotoxicosis

Carbon monoxide is thought to serve as a new endogenous mediator in the pathogenesis of sepsis and septic shock. In newborn rat endotoxicosis, carbon monoxide levels in the circulation as well as liver, kidney and lung were found to be significantly increased (P < 0.05). Moreover, the elevations of carbon monoxide correlated with enhanced nitric oxide production as indicated by nitrite/nitrate levels (P < 0.05). Our present data showed for the first time that endogenously produced carbon monoxide was increased during the course of shock-like states, which suggested that the role of carbon monoxide in sepsis and septic shock might worth further study.

[Ontogeny of Curcuma longa L]

Based on the research of growth of organs, accumulation of dry matter, distribution of photosynthetic production and displacement of growth centre, the growth of turmeric can be divided into three stages. There are 13 leaves in the life of turmeric. Leaf formation takes place rapidly to form 8 leaves in the seedling stage. The leaf area and increase of dry matter per day in roots and leaves are smaller or lower in the seedling stage. In the daughter rhizome formation stage, NAR reaches the maximum (3.54/m2.d), and the leaf area reaches the maximum(3302.9 cm2/plant, LAI 4.95). Before the daughter rhizome formation stage, more than 75% of dry matters are distributed in leaves, and in the daughter rhizome formation stage, 50%-75% of dry matters are distrbuted in leaves. In the late growing period, more than 40% of dry matters are distributed in the daughter rhizome. The growth centre of turmeric changes two times in life. When CGRr is equal to CGRt, the crossing of CGRt and CGRr curves may be regarded as the evidence of the transfer of growth centre from leaves to daughter rhizome.

Reduction of allergic airway responses in P-selectin-deficient mice

P-selectin is an adhesion receptor that has been shown to be important in the recruitment of eosinophils and lymphocytes in a variety of inflammatory conditions. Because cellular recruitment is thought to be a critical event in allergen-induced changes in airway responsiveness, we reasoned that P-selectin-deficient mice would exhibit reduced airway responsiveness and cellular trafficking noted in wild-type (+/+) mice. Both (+/+) and P-selectin-deficient (-/-) mice sensitized and challenged with ovalbumin (OVA/OVA) exhibited the same capacity to produce increased titers of total and OVA-specific immunoglobulin E. Airway responsiveness to methacholine was significantly greater in the (+/+) (OVA/OVA) animals than it was in the respective (-/-) (OVA/OVA) group or control groups (P = 0.0016). Bronchoalveolar lavage fluid from (-/-) (OVA/OVA) mice contained significantly fewer eosinophils and lymphocytes compared with the (+/+) (OVA/OVA) mice (P < 0.05). These results suggest that the predominant role of P-selectin in OVA-induced airway hyperresponsiveness is to promote the airway inflammatory response to allergen inhalation.

Up-regulation of Syk activity during HL60 cell differentiation into granulocyte but not into monocyte/macrophage-lineage

Following induction of cell differentiation in vitro, an increase in Syk activity was observed only in HL60 cells differentiation into granulocytes induced by all trans retinoic acid (RA) but not into macrophages induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) or monocytes induced by sodium butyrate. This elevation of Syk activity was the specific increase in kinase activity because the Syk amount was not altered before and after differentiation. Anti-phosphotyrosine blot revealed that tyrosine phosphorylation of Syk was significantly increased as the function of induction time by RA, but not by TPA and sodium butyrate, suggesting that tyrosine phosphorylation might account for Syk activation. More importantly, Syk tyrosine phosphorylation and Syk activity were not altered in U937 and K562 cells which undergo monocyte differentiation and no differentiation, respectively, in response to RA induction. Taken together, Syk might exert a unique role in directing HL60 cells toward granulocyte differentiation.

Distinctive functions of Syk and Lyn in mediating osmotic stress- and ultraviolet C irradiation-induced apoptosis in chicken B cells

By taking advantage of the established chicken B cell line, DT40 cells, which do not express tyrosine kinase Syk or Lyn, functional roles of Syk and Lyn in apoptotic response elicited by cellular stress were investigated. DT40 cells underwent apoptosis after hyperosmotic stress. In Syk-deficient DT40 cells, this apoptotic process was significantly enhanced. Ectopic expression of wild type, but not kinase-inactive, porcine Syk in Syk-deficient cells rescued cells from osmotic stress-induced apoptosis, demonstrating that the presence of functionally active Syk is necessary to protect cells from osmotic stress-induced apoptosis. In comparison, there was no effect on osmotic stress-induced apoptosis in Lyn-deficient DT40 cells. Interestingly, while Syk was not involved in ultraviolet C (UVC)-induced apoptosis, a deficiency of Lyn rendered cells resistant to UVC irradiation. These observations defined Syk and Lyn as important mediators of apoptosis in DT40 cells in response to osmotic stress and UVC irradiation, respectively. Furthermore, osmotic stress, but not UVC irradiation, could activate c-Jun N-terminal kinase (JNK) in DT40 cells. A deficiency in either Syk or Lyn did not affect the osmotic stress-induced activation of JNK. We, therefore, concluded that Syk and Lyn regulate the apoptotic responses to osmotic stress and UVC irradiation independently of the JNK pathway in DT40 cells.

T-lymphocytes regulate genetically determined airway hyperresponsiveness in mice

Airway hyperresponsiveness (AHR) is a hallmark of asthma and a heritable polygenic trait in the mouse. In the mouse, candidate gene products of hematopoietic origin implicated in asthma mapped to the regions of the previously defined quantitative trait loci. Since hematopoietic cells have been implicated in the pathogenesis of asthma, we evaluated the role of hematopoietic cells in general and T cells specifically in the genetic modulation of native airway responsiveness in mice. Here, with the use of bone marrow transplantation, anti-T-cell monoclonal antibody treatment and T-cell transfer, we demonstrate that intrinsic non-atopic AHR is mediated by T lymphocytes. Our data support the novel concept that, in the absence of identified environmental influences, T cells enhance genetically determined airway responsiveness.

Interleukin-8 receptor B immunoreactivity in brain and neuritic plaques of Alzheimer's disease

Cytokines mediate inflammatory responses through their receptors in the hematopoietic system. In a search for potential mediators of inflammatory responses in Alzheimer's disease, we examined brain for cytokine receptors. Herein we describe interleukin-8 receptor B (IL-8RB, also termed CXCR2) immunoreactivity in the central nervous system. Strong IL-8RB immunoreactivity is present in both Alzheimer's disease and control brains. Neurons, dendrites, and axons are clearly immunoreactive. In Alzheimer's disease, IL-8RB immunoreactivity is also present in some swollen dystrophic neurites of neuritic plaques. Double staining and confocal microscopic analysis reveals that these IL-8RB-positive neurites in plaques are neurofilament positive and are distinct from astrocytic or microglial processes. In general, these IL-8RB-positive neurities do not co-localize with PHF-1 or AT8 (hyperphosphorylated tau) immunoreactive neurites but instead co-localize with beta PP-positive neurites. These results demonstrate for the first time IL-8RB immunoreactivity in the central nervous system and imply a new role for this receptor outside the hematopoietic system. The strong presence of IL-8RB on neurons and the potential of glial cells to produce IL-8 suggest that this system might mediate neuronal-glial interactions.

[Optimal high-yield agronomic measures for Curcuma longa L]

Regression method of orthogonal conic substitution with factors was employed to build up a tuber yield simulation model. Three main measures (sowing time, plant population, application rate of fertilizer) affecting the tuber yield were analyzed by the mathematical model of three unknown second order orthogonal rotative regression. The optimal agronomic measures were obtained. The results indicate that sowing time and plant population play a important role in raising the tuber yield. Sowing time is clearly interrelated with plant population, and likewise, plant population application rate of fertilizer.

Infiltration of eosinophils into the asthmatic airways caused by interleukin 5

Interleukin (IL)-5 is thought to play an important role in asthmatic bronchial mucosal inflammation and is a potential therapeutic target. To investigate the effect of IL-5 on the infiltration of eosinophils in airway in vivo, we compared eosinophil counts and their activation status in airways without and after the topical instillation of recombinant human IL-5. Eight subjects with mild atopic asthma underwent initial bronchoscopy during which control bronchoalveolar lavage (BAL) fluid as well as bronchial mucosa were obtained, and at the same time, normal saline and IL-5 were administered to two sublobar segments separately. The second bronchoscopy were carried out and samples from challenged sites were taken 24 h later. It was found that the total eosinophils (BMK-13+ cells) and the activated eosinophils (EG2+ cells) in bronchial mucosa, the eosinophil numbers in BAL fluid, as well as eosinophil cationic protein (ECP) in BAL fluid from saline-challenged segments were not different from those in unchallenged segments. However, a significant eosinophilia was observed in bronchial mucosa and BAL fluid from IL-5-challenged sites. Eosinophil activation, as assessed by secretion of ECP, was also increased significantly in bronchial mucosa and BAL fluid. The results strongly suggested that IL-5 is capable of inducing eosinophil infiltration into the asthmatic airways, as well as the activation of infiltrating eosinophils.

[Effect of heat, noise and their combination on plasma and myocardial angiotensin II in rats]

Effects of heat (40 degrees C, relative humidity 82%), noise (115dB) and the combination of heat and noise on angiotensin (A II) content in plasma and myocardia was observed in rats. The results showed: (1) plasma A II in control group, heat group, noise group and combined group were 358.72 +/- 35.78, 624.08 +/- 36.32, 783.27 +/- 34.32 and 619.65 +/- 37.72 pg/ml respectively. The A II content in heat group, noise group and combined group are significantly higher than that of the control group (P<0.01). The increase in noise group was significant as compared with those in the heat group and combined group (P<0.05). (2) The myocardia A II in control group, heat group, noise group and combined group were 594.78 +/- 82.46, 935.10 +/- 15l.51, 326.22 +/- 28.45, and 438.37 +/- 58.63 pg/mg W.W respectively. The myocardial A II content in heat group was significantly higher (P<0.01), but that in noise group than the control was significantly lower(P<0.O5).

[Effect of cultivating measures on the tuber yield of Curcuma longa L]

The effect of cultivating measures on the tuber yield of Curcuma longa was observed. dibble planting has been proved move effective in raising the tuber yield than drill culture, and the dibble planting quantity has no effect on the tuber. The rational producing area, soil, seed tuber and so on were selected according to the experiments.

Syk-dependent and -independent signaling cascades in B cells elicited by osmotic and oxidative stress

It was found that Syk protein-tyrosine kinase is rapidly activated in B cells after H2O2 treatment (oxidative stress) or increased extracellular NaCl concentration (osmotic stress) as well as in response to B cell receptor activation. In this study we examined the involvement of Syk in responses elicited by these types of extracellular stress, particularly Ca2+ responses and c-Jun amino-terminal kinase (JNK) activation, using a chicken B cell line, DT40, as well as the DT40-derived mutant DT40/Syk(-), which does not express Syk. Osmotic stress evokes increases in [Ca2+]i by stimulating an extracellular Ca2+ influx in both DT40 and DT40/Syk(-) cells. In comparison, oxidative stress elicits an increase in [Ca2+]i by stimulating both an extracellular Ca2+ influx and Ca2+ release from internal stores in DT40 cells, but this Ca2+ response is partially abolished in DT40/Syk(-) cells, indicating that the oxidative stress-induced Ca2+ response is at least partly dependent on Syk. Interestingly, the depletion of Ca2+ results in a significantly decreased level of Syk activation in DT40 cells stimulated by oxidative but not osmotic stress. Furthermore, JNK is activated to different extents by these two types of stress. The extent of JNK activation in DT40/Syk(-) cells in response to osmotic stress is comparable to that observed in DT40 cells. Intriguingly, oxidative stress-induced JNK activation is significantly compromised in DT40/Syk(-) cells. Collectively, these results indicate that both the Ca2+ response and JNK activity induced by oxidative stress are partly dependent on Syk, whereas those induced by osmotic stress are independent of Syk.

Chemokine receptor usage by human eosinophils. The importance of CCR3 demonstrated using an antagonistic monoclonal antibody

Chemokines bind and signal through G-protein coupled seven transmembrane receptors. Various chemokine receptors are expressed on leukocytes, and these may impart selective homing of leukocyte subsets to sites of inflammation. Human eosinophils express the eotaxin receptor, CCR3, but respond to a variety of CC chemokines apart from eotaxin, including RANTES, monocyte chemotactic protein (MCP)-2, MCP-3, and MCP-4. Here we describe a mAb, 7B11, that is selective for CCR3 and has the properties of a true receptor antagonist. 7B11 blocked binding of various radiolabeled chemokines to either CCR3 transfectants, or eosinophils. Pretreatment of eosinophils with this mAb blocked chemotaxis and calcium flux induced by all CCR3 ligands. In all individuals examined, including allergic and eosinophilic donors, > 95% of the response of eosinophils to eotaxin, RANTES, MCP-2, MCP-3, and MCP-4 was shown to be mediated through CCR3. The IL-8 receptors, particularly CXCR2, were induced on IL-5 primed eosinophils, however these eosinophils responded to CC chemokines in the same manner as unprimed eosinophils. These results demonstrate the importance of CCR3 for eosinophil responses, and the feasibility of completely antagonizing this receptor.

Discrete steps in binding and signaling of interleukin-8 with its receptor

The mechanisms by which chemokines bind and signal through their receptors are complex and poorly understood. In the present study, we sought to dissect these processes and to map important functional domains of the two CXC chemokine (interleukin-8) receptors, CXCR1 (formally IL-8RA) and CXCR2 (formally IL-8RB), using blocking monoclonal antibodies (mAbs) to the receptors and a series of chimeras between CXCR1 and CXCR2. A panel of specific mAbs against CXCR1 or CXCR2, generated by immunizing mice with transfectants expressing either receptor, were shown to effectively block IL-8- and/or growth-related oncogene alpha (GROalpha) -mediated ligand binding, chemotaxis, elastase release, and VCAM-1 binding in CXCR1 and CXCR2 transfectants and/or human neutrophils. Of particular interest was an anti-CXCR1 mAb, 7D9, that inhibited chemotaxis, elastase release, and VCAM-1 binding but had no detectable effects on ligand binding. The epitopes of these blocking mAbs were mapped by using a series of CXCR1/2 chimera transfectants and synthetic peptides. Most of the anti-CXCR1 antibodies, except 7D9, mapped to the amino acid sequence WDFDDL (CXCR1 residues 10-15), and all the anti-CXCR2 antibodies mapped to the amino acid sequence FEDFW (CXCR2 residues 6-10). The epitope of mAb 7D9 mainly involved a region within the first 45 residues of CXCR1, and it appeared to be conformation-sensitive. These results support a model in which the binding and signaling of IL-8 with its receptor occur in at least two discrete steps involving distinct domains of the receptor. This model is consistent with the notion that discrete conformational changes of the receptor secondary to ligand binding are required to trigger various biological responses. Moreover, the ligand binding and chemotaxis properties of each CXCR1/2 chimeric receptor to IL-8 and GROalpha were determined. It was found that each is distinct in its ability to confer ligand binding and chemotactic response to IL-8 and GROalpha, and two conclusions could be made. 1) The N-terminal segment of CXCR1 is a dominant determinant of receptor subtype selectivity, consistent with previous studies using rabbit/human CXCR1/2 chimeras; and 2) the specificity determinant for GROalpha binding in CXCR2 involves sequences in the N terminus, distal to the first 15 residues, as well as other parts of the receptor.

[Patterns of systematic development for the resources of traditional Chinese drugs and herbs in the Three Gorges Reservoir areas]

Based on the comprehensive survey, the status and countermeasures of systematic development for the resources of traditional Chinese drugs and herbs in the rural exploitative emigration and eco-agricultural economy in the Three Gorges Reservoir Areas are put forth constructively.

[Effect of organic fertilizer and mineral fertilizer on the tuber yield of Curcuma longa L]

Regression method of orthogonal conic substitution with factors was employed to build up the tuber models for yield, quality and benefit. Three main measures affecting the tuber yield, quality and benefit were analyzed by these mathematical models. The effect of agronomic measures on the tuber yield is human and livestock excreta, rape cake > Ca3(PO4)2 > KCl. The optimal combination of farming practices has been obtained according to the analysis of these models.

[Curcuma longa L. tuber yield simulation model and its application under combined agronomic measures for good-quality, high-yield and obvious economic results]

A design of second order orthogonal rotative regression was developed and field tested, and the tuber models for yield, quality and benefit were simulated and built. The effect of agronomic measures on the tuber yield is plant density > phosphorus > sowing date > nitrogen > potassium. There is a clear interrelation effect among agronomic measures. The results of simulation experiment have shown that the optimal combination of farming practices can greatly increase the tuber yield, quality and benefit, and is adjusted according to climate, soil, ferilizer or manure sources, and so on.

[Folk medicine of the Qiang nationality]

Based on a two-year investigation of folk medicine of the Qiang Nationality, systematic studies have been made on its formation and development, specific methods of physical therapy and experiences and features of clinical application.

Biology of chemokine and classical chemoattractant receptors: differential requirements for adhesion-triggering versus chemotactic responses in lymphoid cells

Several chemoattractant receptors can support agonist-induced, integrin-dependent arrest of rolling neutrophils in inflamed venules in vivo, as well as subsequent crawling into tissues. It has been hypothesized that receptors of the Galpha(i)-linked chemoattractant subfamilies, especially receptors for chemokines, may mediate parallel activation-dependent arrest of homing lymphocyte subsets. However, although several chemokines can attract subsets of B or T cells, robust chemoattractant triggering of resting lymphocyte adhesion to vascular ligands has not been observed. To study the biology of individual leukocyte chemoattractant receptors in a defined lymphoid environment, mouse L1/2 pre-B cells and/or human Jurkat T cells were transfected with alpha (IL-8 receptor A) or beta (MIP-1alpha/CC-CKR-1) chemokine receptors, or with the classical chemoattractant C5a (C5aR) or formyl peptide receptors (fPR). All receptors supported robust agonist-dependent alpha4beta1 integrin-mediated adhesion of lymphocytes to VCAM-1. L1/2 cells cotransfected with fPR and beta7 integrin were also induced to bind MAdCAM-1, suggesting common mechanisms coupling chemoattractant receptors to activation of distinct integrins. Adhesion was rapid but transient, with spontaneous reversion to unstimulated levels within 5 min after peak binding. When observed under flow conditions, alpha4beta1-mediated arrest occurred within seconds after initiation of contact and rolling of IL-8RA transfectants on VCAM-1/IL-8 co-coated surface; and arrest reversed spontaneously after a mean of 5 min with a return to rolling behavior. Each of the receptors also conferred agonist-specific chemotaxis; however, whereas strong adhesion required simultaneous occupancy of many receptors with maximal responses above the Kd, chemotaxis in each case was suppressed at high agonist concentrations. The findings indicate that alpha and beta chemokine as well as classical chemoattractant receptors can trigger robust adhesion as well as directed migration of lymphoid cells, but that the requirements for and kinetics of adhesion triggering and chemotaxis are distinct, thus permitting their independent regulation. They suggest that the discordance between proadhesive and chemoattractant responses of circulating lymphocytes to many chemokines may reflect quantitative aspects of receptor expression and/or coupling rather than qualitative differences in receptor signaling.

Different functions for the interleukin 8 receptors (IL-8R) of human neutrophil leukocytes: NADPH oxidase and phospholipase D are activated through IL-8R1 but not IL-8R2

Two monoclonal antibodies, anti-IL8R1 and anti-IL8R2, raised against both interleukin 8 receptors (IL-8R) of human neutrophils, IL-8R1 and IL-8R2, were used to study individual receptor functions after stimulation with IL-8, GRO alpha, or NAP-2. Efficacy and selectivity of the antibodies were tested in Jurkat cells transfected with cDNA coding for one or the other receptor. The binding of 125 I labeled IL-8 and IL-8-induced changes of the cytosolic free Ca2+ concentration were inhibited by anti-IL8RI in cells expressing IL-8R1 and by anti-IL8R2 in cells expressing IL-8R2. In human neutrophils, release of elastase was observed after stimulation with IL-8 or GRO alpha. The response to IL-8 was inhibited slightly by anti-IL8R1 and more substantially when both monoclonal antibodies were present, while the response to GRO alpha was inhibited by anti-IL8R2 but was not affected by anti-IL8R1. These results indicate that both IL-8 receptors can signal independently for granule enzyme release. Superoxide production, a measure of the respiratory burst, was obtained with increasing concentrations of IL-8 with maximum effects at 25 to 50 nM, but no response was observed upon challenge with GRO alpha or NAP-2 up to 1000 nM. The superoxide production induced by IL-8 was inhibited by anti-IL8R1, but was not affected by anti-IL8R2. Stimulation of neutrophils with IL-8, in contrast to GRO alpha or NAP-2, also elicited phospholipase D activity. The effect of IL-8 was again inhibited by anti-IL-8R1 but not by anti-IL8R2, indicating that this response, like the respiratory burst, was mediated by IL-8R1. Taken together, our results show that IL-8R1 and IL-8R2 are functionally different. Responses, such as cytosolic free Ca2+ changes and the release of granule enzymes, are mediated through both receptors, whereas the respiratory burst and the activation of phospholipase D depend exclusively on stimulation through IL-8R1.