Biomedical subjects

J Van Damme

Publications and source records attributed to J Van Damme.

At least 19 recordsLinked to original sources

PubMed2006

Expression of chemokines and gelatinase B in sympathetic ophthalmia.

PURPOSE: To examine the expression of gelatinase B (matrix metalloproteinase-9) and the chemokines monocyte chemotactic protein-1 (CCL2/MCP-1) and stromal cell-derived factor-1 (CXCL12/SDF-1) in sympathetic ophthalmia (SO). METHODS: Five enucleated exciting eyes with a clinical diagnosis and typical histopathological findings of SO were studied by immunohistochemical techniques using a panel of monoclonal antibodies directed against gelatinase B, MCP-1, and SDF-1. In addition, a panel of monoclonal and polyclonal antibodies was used to characterize the composition of the inflammatory infiltrate. RESULTS: In all cases, the extensive uveal inflammatory infiltrate was organized as a diffuse infiltrate and as large granulomas consisting of epithelioid cells and multinucleated giant cells. CD20(+) B lymphocytes predominated in the diffuse infiltrate and CD3(+) T lymphocytes were few. The monocyte/macrophage marker CD68 was expressed in scattered inflammatory mononuclear cells and within granulomas and Dalen-Fuchs nodules. Most of the inflammatory cells were HLA-DR(+). Immunoreactivity for gelatinase B, MCP-1, and SDF-1 was observed in cells within granulomas and in scattered epithelioid cells. Immunoreactivity for MCP-1 was noted in retinal pigment epithelial cells. Endothelial cells of choriocapillaries showed weak immunoreactivity for SDF-1. CONCLUSIONS: Gelatinase B, MCP-1, and SDF-1 might have a pathogenic role in the recruitment of leucocytes into the eye in SO.

Adult↗

PubMed2006

Natural post-translational modifications of chemokines.

Chemokines, adhesion molecules, cytokines and proteases regulate the extravasation of leucocytes during acute and chronic inflammation and leucocyte homing. Chemokines are produced after transcriptional activation by inflammatory mediators such as cytokines or microbial Toll-like receptor ligands and their effect depends on the expression of chemokine receptors on specific cell types. More and more evidence points towards a role for post-translational modifications in the fine-tuning of chemokine activity. Although both glycosylation and proteolytic processing of the C- and/or N-terminus of chemokines has been reported, mainly proteolytic processing of the N-terminus appears to affect the receptor specificity, chemotactic property and signalling potency of these low-molecular-mass proteins. N-terminal processing of chemokines by aminopeptidases or endoproteases may alter the receptor specificity and may result in up- or down-regulation of their chemotactic, antiviral or angiogenic activity.

Animals↗

PubMed2006

Chemokines in gastrointestinal disorders.

The intestine is constantly challenged by food antigens and pathogens and is therefore in need of a good working innate and adaptive immune response. Chemokines are important modulators as they assure the directed movement of immune cells within the body. In addition, chemokines play an important role in hematopoiesis, angiogenesis and tumor metastasis. This review focuses on chemokines and gastrointestinal disorders, more particularly on inflammatory bowel diseases and gastrointestinal tumors. In a first part, the current knowledge on chemokine expression in inflammatory bowel diseases is summarized. Idiopathic inflammatory bowel diseases are characterized by an uncontrolled immune response. The resulting chronic inflammation of the intestine involves massive infiltration of immune cells, causing intestinal damage by the release of cytokines and proteolytic enzymes. Chemokines are believed to be key mediators in this process of aberrant leukocyte recruitment. Chemokine expression in inflammatory bowel disease strongly correlates with the grade of disease activity. The potential therapeutic use of chemokines in gastrointestinal tumors by the use of gene therapy is also reviewed. Chemokines have therapeutic potential in anti-tumor therapy by their angiostatic effect. On the other hand, chemokines can augment the cell-mediated adaptive immune response and thereby exert anti-tumor activity. However, chemokines can passively favor escape of tumor cells by stimulating the release of tissue degrading matrix metalloproteinases and can actively promote metastasis of chemokine receptor-expressing tumor cells.

Animals↗

PubMed2004

Generation of glycosylated remnant epitopes from human collagen type II by gelatinase B.

Gelatinase B/matrix metalloproteinase-9 (MMP-9) is an inflammatory mediator and effector. Considerable amounts of gelatinase B are released by neutrophils in the synovial cavity of patients with rheumatoid arthritis, and gelatinase B-deficient mice are resistant against antibody-induced arthritis. Native human collagen type II is susceptible to cleavage by various collagenases (MMP-1, MMP-8, and MMP-13), which cleave at a single position in the triple helix. Although the triple-helical structure may persist after this single cleavage, we show that gelatinase B degrades the resulting fragments into small remnant peptides. These were identified by mass spectrometry and Edman degradation. Localization of 31 cleavage sites shows that the immunodominant epitopes remain intact after cleavage and may become available, processed as antigens and presented in MHC-II molecules. Furthermore, most post-translational modifications were identified on the fragments, including nine glycosylation sites. In particular, it is shown for the first time by structural analysis that in natural human collagen II, lysines in the main immunodominant epitope are modified by partial hydroxylation and partial glycosylation. Determination of T-cell reactivity against such fragments indicates that, besides the two known main immunodominant epitopes, other glyco-epitopes may be present in collagen II. This reinforces the role of glycopeptide antigens in autoimmunity.

Antigen Presentation↗

PubMed2002

Up-regulation of FPR2, a chemotactic receptor for amyloid beta 1-42 (A beta 42), in murine microglial cells by TNF alpha.

Human FPRL1 and its mouse homologue FPR2 are functional receptors for several exogenous and host-derived chemotactic peptides, including amyloid beta(42) (A beta(42)), a critical pathogenic factor in Alzheimer's disease. We investigated the effect of TNF alpha on the expression and function of FPR2 in mouse microglial cells, a crucial inflammatory cell type in the CNS. Primary murine microglia and a cell line N9 in resting state expressed low levels of FPR2 gene and lacked the response to chemotactic agonists for this receptor. Incubation with TNF alpha, however, increased microglial expression of FPR2 gene, in association with potent chemotactic responses to FPR2-specific agonists including A beta(42). The effect of TNF alpha was dependent on the p55 TNF alpha receptor and activation of MAP kinase p38. TNF alpha concomitantly down-regulated microglial response to the chemokine SDF-1 alpha. Thus, by selectively up-regulating FPR2 in microglia, TNF alpha has the capacity to amplify host response in inflammatory diseases in the CNS.

Amyloid beta-Peptides↗

PubMed2002

Neutrophil gelatinase B and chemokines in leukocytosis and stem cell mobilization.

Leukocytosis is a physiopathological mechanism primarily to combat infections, whereas stem cell mobilization is induced for therapeutical purposes. Both processes are dependent on the balance between leukocyte and stem cell retention and mobilization. The retention is mediated by the specific architecture of the bone marrow, adhesion molecules and the production of chemokines in the bone marrow, which attract escaped immature cells to the marrow. Mobilization is the effect of the action of "peripheral" chemokines, such as interleukin-8 (IL-8 or CXCL8) and the remodeling of the matrix and basement membranes by matrix enzymes, such as gelatinase B (MMP-9). Recent studies lead to the conclusion that neutrophils, IL-8/CXCL8 and gelatinase B/MMP-9 play control roles in leukocytosis and stem cell mobilization. Neutrophils are the predominant circulating leukocyte type and IL-8/CXCL8 is the major neutrophil chemoattractant in humans. Gelatinase B and no gelatinase A is rapidly released from prestored granules after activation of neutrophils by IL-8/CXCL8. Moreover, neutrophils do not produce TIMP-1 and can chemically activate latent progelatinase B. Activated gelatinase B catalyses the aminoterminal truncation of IL-8/CXCL8 into a tenfold more potent chemokine. This implies that, when IL-8/CXCL8 appears in the circulation, the bone marrow is instructed to release neutrophils and concomitantly stem cells. These studies suggest that IL-8/CXCL8 and gelatinase B/MMP-9 are targets for the modulation of stem cell mobilization.

Animals↗

PubMed2002

Expression of T lymphocyte chemoattractants and activation markers in vernal keratoconjunctivitis.

BACKGROUND/AIMS: T lymphocytes are present in increased numbers in the conjunctiva of patients with vernal keratoconjunctivitis (VKC) and their activation has a central role in the pathogenesis of the chronic allergic inflammatory reactions seen in VKC. The aims of this study were to examine the expression of three recently described potent T lymphocyte chemoattractants, PARC (pulmonary and activation regulated chemokine), macrophage derived chemokine (MDC), and I-309, the MDC receptor CCR4, and T lymphocyte activation markers, CD25, CD26, CD62L, CD71, and CD30, and to correlate them with the counts of CD3(+) T lymphocytes in the conjunctiva of patients with VKC. METHOD: Conjunctival biopsy specimens from 11 patients with active VKC, and eight control subjects were studied by immunohistochemical techniques using a panel of monoclonal and polyclonal antibodies directed against PARC, MDC, I-309, CCR4, CD25, CD26, CD62L, CD71, and CD30. The numbers of positively stained cells were counted. The phenotype of inflammatory cells expressing chemokines was examined by double immunohistochemistry. RESULTS: In the normal conjunctiva, vascular endothelial cells in the upper substantia propria showed weak immunoreactivity for CD26. There was no immunoreactivity for the other antibodies. VKC specimens showed inflammatory cells expressing PARC, MDC, and I-309. The numbers of PARC(+) inflammatory cells were higher than the numbers of MDC(+) and I-309(+) inflammatory cells and the mean values of the three groups differed significantly (17.0 (SD 10.1); 9.5 (9.9), and 4.3 (7.9), respectively, p = 0.0117, ANOVA). The numbers of PARC(+) inflammatory cells had the strongest correlation with the numbers of CD3(+) T lymphocytes. Few CCR4(+) inflammatory cells were observed in only three specimens. Double immunohistochemistry revealed that all inflammatory cells expressing chemokines were CD68(+) monocytes/macrophages. The numbers of CD25(+) T lymphocytes were higher than the numbers of CD26(+), CD62L(+), CD71(+), and CD30(+) T lymphocytes and the mean values of the five groups differed significantly (46.2 (27.9), 30.7 (16.0), 20.1 (8.6), 7.8 (7.7), and 6.5 (4.0), respectively, p <0.001, ANOVA). The numbers of CD25(+) T lymphocytes had the strongest correlation with the numbers of CD3(+) T lymphocytes. CONCLUSION: These results suggest a potential role for PARC, MDC, and I-309 in attracting T lymphocytes into conjunctiva in VKC. T lymphocytes in VKC are activated and express several activation markers which might contribute to the pathogenesis of VKC.

Adolescent↗

PubMed2002

Chemokines and proteinases in autoimmune diseases and cancer.

Chemotactic cytokines or chemokines form a family of proinflammatory proteins that are functionally linked to various classes of proteases, including matrix metalloproteinases (MMPs). Both families of molecules are key players in the migration of inflammatory cells in autoimmune diseases and in invasive cancers. For example, the chemokine interleukin-8 acts as a fast secretagogue of gelatinase B in granulocytes and is increased in the synovial fluid of arthritis patients and may locally recruit and activate neutrophils. The latter are the most abundant inflammatory cell type in the joints of patients with rheumatoid arthritis. In the case of the inflamed joint, the contribution of matrix remodeling enzymes in the breakdown of cartilage and bone is trivial. Gelatinase B (MMP-9) was documented in autoimmune diseases and cancer by immunohistochemistry with the use of monoclonal antibodies. Studies in rheumatoid arthritis and multiple sclerosis led us to postulate the "Remnant Epitopes Generate Autoimmunity" or REGA model for autoimmunity. This model is based on the pathophysiological role of three major classes of molecules involved in aspecific primary immune defense mechanisms: the cytokines, the chemokines and the proteases. The REGA model has proven to be useful for the development of disease treatment strategies. Particular cytokines are disease-limiting and may thus be used for the treatment of autoimmune disorders. Cytokines and chemokines that induce enzymes promote disease and may be antagonized. Along this line of research, we have recently identified natural and biosynthetic chemokine antagonists. Some of these have shown potent antiviral activity against human immunodeficiency virus. It is expected that these might also become useful in the treatment of autoimmune diseases and invasive cancers. A similar effect may be expected by the antagonization of damaging proteases or with the use of recombinant or synthetic enzyme inhibitors.

Autoimmune Diseases↗

PubMed2001

Amino-terminal truncation of CXCR3 agonists impairs receptor signaling and lymphocyte chemotaxis, while preserving antiangiogenic properties.

The interferon (IFN)-inducible chemokines, specifically, IFN-gamma-inducible protein-10 (IP-10), monokine induced by IFN-gamma (Mig), and IFN-inducible T-cell alpha-chemoattractant (I-TAC), share a unique CXC chemokine receptor (CXCR3). Recently, the highly specific membrane-bound protease and lymphocyte surface marker CD26/dipeptidyl peptidase IV (DPP IV) was found to be responsible for posttranslational processing of chemokines. Removal of NH(2)-terminal dipeptides by CD26/DPP IV alters chemokine receptor binding and signaling, and hence inflammatory and anti-human immunodeficiency virus (HIV) activities. CD26/DPP IV and CXCR3 are both markers for Th1 lymphocytes and, moreover, CD26/DPP IV is present in a soluble, active form in human plasma. This study reports that at physiologic enzyme concentrations CD26/DPP IV cleaved 50% of I-TAC within 2 minutes, whereas for IP-10 and Mig the kinetics were 3- and 10-fold slower, respectively. Processing of IP-10 and I-TAC by CD26/DPP IV resulted in reduced CXCR3-binding properties, loss of calcium-signaling capacity through CXCR3, and more than 10-fold reduced chemotactic potency. Moreover, IP-10 and I-TAC cleaved by CD26/DPP IV acted as chemotaxis antagonists and CD26/DPP IV-truncated IP-10 and Mig retained their ability to inhibit the angiogenic activity of interleukin-8 in the rabbit cornea micropocket model. These data demonstrate a negative feedback regulation by CD26/DPP IV in CXCR3-mediated chemotaxis without affecting the angiostatic potential of the CXCR3 ligands IP-10 and Mig.

Angiogenesis Inhibitors↗

PubMed2001

Kinetic study of the processing by dipeptidyl-peptidase IV/CD26 of neuropeptides involved in pancreatic insulin secretion.

Dipeptidyl-peptidase IV (DPPIV/CD26) metabolizes neuropeptides regulating insulin secretion. We studied the in vitro steady-state kinetics of DPPIV/CD26-mediated truncation of vasoactive intestinal peptide (VIP), pituitary adenylyl cyclase-activating peptide (PACAP27 and PACAP38), gastrin-releasing peptide (GRP) and neuropeptide Y (NPY). DPPIV/CD26 sequentially cleaves off two dipeptides of VIP, PACAP27, PACAP38 and GRP. GRP situates between the best DPPIV/CD26 substrates reported, comparable to NPY. Surprisingly, the C-terminal extension of PACAP38, distant from the scissile bond, improves both PACAP38 binding and turnover. Therefore, residues remote from the scissile bond can modulate DPPIV/CD26 substrate selectivity as well as residues flanking it.

Dipeptidyl Peptidase 4↗

PubMed2001

Gene cloning of a new plasma CC chemokine, activating and attracting myeloid cells in synergy with other chemoattractants.

Chemokines are important mediators of cell migration during inflammation and normal leukocyte trafficking. Inflammatory chemokines are induced in multiple cell types at sites of infection. Here, we describe a novel bovine CC chemokine, designated regakine-1, that is constitutively present at high concentrations in plasma. Cloning of its gene revealed an expected two intron/three exon organization, with a rather long first intron. In addition to a 21-residue signal peptide, the coding sequence corresponded to a 71-residue secreted protein. However, the natural regakine-1 protein missed the COOH-terminal lysine residue. Regakine-1 has only weak sequence similarity (<50% identical residues) with other animal or human chemokines. Northern blot analysis demonstrated regakine-1 RNA expression in spleen and lung. At physiological concentrations (30-100 ng/mL), natural 7.5 kDa regakine-1 stimulated gelatinase B release from neutrophils and chemoattracted immature myeloid HL-60 cells, as well as mature granulocytes. Regakine-1 was more potent on human myeloid cells than the human plasma CC chemokine hemofiltrate CC chemokine-1 (HCC-1). Moreover, regakine-1 synergized with the bacterial peptide N-formylmethionylleucylphenylalanine (fMLP), yielding a 10-fold increase in neutrophil chemotactic response above their additive effect. Regakine-1 did not compete with interleukin-8 (IL-8) for binding to neutrophils, nor did it affect fMLP-induced calcium signaling, suggesting that regakine-1 recognizes a different receptor. In view of its high constitutive plasma concentration, regakine-1 is believed to recruit myeloid cells into the circulation, whereas its synergy with other neutrophil chemoattractants suggests that it also enhances the inflammatory response to infection.

Amino Acid Sequence↗

PubMed2001

Kinetic investigation of chemokine truncation by CD26/dipeptidyl peptidase IV reveals a striking selectivity within the chemokine family.

Chemokines coordinate many aspects of leukocyte migration. As chemoattractants they play an important role in the innate and acquired immune response. There is good experimental evidence that N-terminal truncation by secreted or cell surface proteases is a way of modulating chemokine action. The localization of CD26/dipeptidyl peptidase IV on cell surfaces and in biological fluids, its primary specificity, and the type of naturally occurring truncated chemokines are consistent with such a function. We determined the steady-state catalytic parameters for a relevant selection of chemokines (CCL3b, CCL5, CCL11, CCL22, CXCL9, CXCL10, CXCL11, and CXCL12) previously reported to alter their chemotactic behavior due to CD26/dipeptidyl peptidase IV-catalyzed truncation. The results reveal a striking selectivity for stromal cell-derived factor-1alpha (CXCL12) and macrophage-derived chemokine (CCL22). The kinetic parameters support the hypothesis that CD26/dipeptidyl peptidase IV contributes to the degradation of certain chemokines in vivo. The data not only provide insight into the selectivity of the enzyme for specific chemokines, but they also contribute to the general understanding of CD26/dipeptidyl peptidase IV secondary substrate specificity.

Amino Acid Sequence↗

PubMed2001

Identification of a blood-derived chemoattractant for neutrophils and lymphocytes as a novel CC chemokine, Regakine-1.

Chemokines constitute a large family of chemotactic cytokines that selectively attract different blood cell types. Although most inflammatory chemoattractants are only induced and released in the circulation during acute infection, a restricted number of CXC and CC chemokines are constitutively present in normal plasma at high concentrations. Here, such a chemotactic protein was purified to homogeneity from serum and fully identified as a novel CC chemokine by mass spectrometry and amino acid sequence analysis. The protein, tentatively designated Regakine-1, shows less than 50% sequence identity with any known chemokine. This novel CC chemokine chemoattracts both neutrophils and lymphocytes but not monocytes or eosinophils. Its modest chemotactic potency but high blood concentration is similar to that of other chemokines present in the circulation, such as hemofiltrate CC chemokine-1, platelet factor-4, and beta-thromboglobulin. Regakine-1 did not induce neutrophil chemokinesis. However, it synergized with the CXC chemokines interleukin-8 and granulocyte chemotactic protein-2, and the CC chemokine monocyte chemotactic protein-3, resulting in an at least a 2-fold increase of the neutrophil and lymphocyte chemotactic response, respectively. The biologic effects of homogeneous natural Regakine-1 were confirmed with chemically synthesized chemokine. Like other plasma chemokines, it is expected that Regakine-1 plays a unique role in the circulation during normal or pathologic conditions.

Amino Acid Sequence↗

PubMed2001

The Gal/GalNAc-specific lectin from the plant pathogenic basidiomycete Rhizoctonia solani is a member of the ricin-B family.

The lectin isolated from the phytopathogenic basidiomycete Rhizoctonia solani (RSA) is a homodimer of two noncovalently associated monomers of 15.5 kDa. RSA is a basic protein (pI > 9) which consists mainly of beta-sheets. A presumed relationship with ricin-B is supported by the sequence similarity between the N-terminus of RSA and the N-terminal subdomain of ricin-B. Hydrophobic cluster analysis confirms that the N-terminus of both proteins has a comparable folding. RSA exhibits specificity towards Gal/GalNAc whereby the hydroxyls at the C3', C4', and C6' positions of the pyranose ring play a key role in the interaction with simple sugars. The carbohydrate-binding site of RSA apparently accommodates only a single sugar unit. Our results demonstrate an obvious evolutionary relationship between some fungal and plant lectins, but also provide evidence for the occurrence of a lectin consisting of subunits corresponding to a single subdomain of ricin-B.

Acetylgalactosamine↗

PubMed2001

Diverging binding capacities of natural LD78beta isoforms of macrophage inflammatory protein-1alpha to the CC chemokine receptors 1, 3 and 5 affect their anti-HIV-1 activity and chemotactic potencies for neutrophils and eosinophils.

Recently, the LD78beta isoform of the CC chemokine macrophage inflammatory protein (MIP)-1alpha was shown to efficiently chemoattract lymphocytes and monocytes and to inhibit infection of mononuclear cells by R5 HIV-1 strains. We have now demonstrated that after cleavage of the NH2-terminal Ala-Pro dipeptide by CD26, LD78beta(3 - 70) became the most potent chemokine blocking HIV-1. LD78beta(3 - 70) competed tenfold more efficiently than LD78beta(1 - 70) with [125I] RANTES for binding to the CC chemokine receptors CCR5 and CCR1. Contrary to LD78alpha, LD78beta(1 - 70) at 30 ng/ml efficiently competed with [125I] RANTES for binding to CCR3 and mobilized calcium in CCR3 transfectants, whereas LD78beta(3 - 70) showed a 30-fold decrease in CCR3 affinity compared to LD78beta(1 - 70). This demonstrates the importance of the penultimate proline in LD78beta(1 - 70) for CCR3 recognition. Both LD78beta isoforms efficiently chemoattracted eosinophils from responsive donors. In contrast, only the CCR3 agonist LD78beta(1 - 70) and not LD78beta(3 - 70), induced calcium increases in eosinophils with low levels of CCR1. In responder neutrophils, LD78beta(3 - 70) elicited calcium fluxes at a 30-fold lower dose (10 ng/ml) compared to intact LD78beta and LD78alpha, whereas the three MIP-1alpha isoforms were equipotent neutrophil chemoattractants. Taken together, both LD78beta isoforms are potent HIV-1 inhibitors (CCR5) and activators for neutrophils (CCR1) and eosinophils (CCR1, CCR3), affecting infection and inflammation.

Animals↗

PubMed2001

Selective induction of CCL18/PARC by staphylococcal enterotoxins in mononuclear cells and enhanced levels in septic and rheumatoid arthritis.

Chemokines are mediators of innate and acquired immunity. CCL18, also designated pulmonary and activation-regulated chemokine (PARC), dendritic cell-derived CC chemokine-1 (DC-CK1), alternative macrophage activation-associated CC chemokine-1 (AMAC-1) and macrophage inflammatory protein-4 (MIP-4), was for the first time isolated from peripheral blood mononuclear cells (PBMC) and biochemically characterized. We found that CCL18/PARC protein is spontaneously secreted by PBMC and is selectively induced in PBMC by staphylococcal enterotoxins (SEA, SEB) and IL-4, but not by IFN-gamma and the CXCL8/IL-8 inducers lipopolysaccharide (LPS) or Concanavalin A. Human fibroblasts, chondrocytes and endothelial cells did not produce CCL18/PARC in response to inflammatory mediators such as measles virus, double-stranded RNA, LPS or IL-1beta, whereas up to 150 ng/ml of CCL2/MCP-1 was induced under these conditions. In synovial fluids from septic and rheumatoid arthritis patients, fourfold-enhanced CCL18/PARC levels (150 ng/ml) were detected compared to those in crystal-induced arthritis and osteoarthritis. In septic arthritis, the synovial levels of CCL18/PARC were fivefold higher than those of CXCL8/IL-8. Immunochemistry revealed CD68(+) monocytes/macrophages as the main CCL18/PARC-producing cell type in both PBMC and arthritic synovial tissue. In addition, CD1a(+) blood dendritic cells expressed CCL18/PARC. These findings suggest that monocytic cells respond to Gram-positive bacterial infection by the production of CCL18/PARC in the synovial cavity.

Arthritis, Infectious↗

PubMed2001

Protein identification based on matrix assisted laser desorption/ionization-post source decay-mass spectrometry.

Due to its very short analysis time, its high sensitivity and ease of automation, matrix-assisted laser desorption/ionization (MALDI)-peptide mass fingerprinting has become the preferred method for identifying proteins of which the sequences are available in databases. However, many protein samples cannot be unambiguously identified by exclusively using their peptide mass fingerprints (e.g., protein mixtures, heavily posttranslationally modified proteins and small proteins). In these cases, additional sequence information is needed and one of the obvious choices when working with MALDI-mass spectrometry (MS) is to choose for post source decay (PSD) analysis on selected peptides. This can be performed on the same sample which is used for peptide mass fingerprinting. Although in this type of peptide analysis, fragmentation yields are very low and PSD spectra are often very difficult to interpret manually, we here report upon our five years of experience with the use of PSD spectra for protein identification in sequence (protein or expressed sequence tag (EST)) databases. The combination of peptide mass fingerprinting and PSD and analysis described here generally leads to unambiguous protein identification in the amount of material range generally encountered in most proteome studies.

Peptide Fragments↗

PubMed2001

Tumor angiogenesis induced by granulocyte chemotactic protein-2 as a countercurrent principle.

Chemokine production by tumors is a well-known phenomenon, but its role in tumor biology remains debatable. Although intratumoral injection of granulocyte chemotactic protein-2 (GCP-2) had no effect on tumor parameters, needle-free stable expression of the chemokine resulted in enhanced tumor growth. It is shown here that tumors that express a potent form of GCP-2 induce a strong influx and activation of tumor-associated neutrophils. The production of GCP-2 leads to intratumoral expression of gelatinase B and advantage for tumor growth by increased angiogenesis. These results are in line with the countercurrent principle of chemokine action and support the notion that paraneoplastic expression of ELR-positive CXC chemokines has to be blocked rather than stimulated in cancer therapy.

Animals↗