Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Persistent infection of human immunodeficiency virus (HIV) takes place in the secondary lymphoid tissues even during clinically latent stages. The CC chemokines secondary lymphoid tissue chemokine (SLC) and EBI1-ligand chemokine (ELC) are constitutively expressed in the secondary lymphoid tissues. They share CCR7 expressed on lymphocytes and mature dendritic cells and play key roles in the trafficking of these types of cells into the secondary lymphoid tissues. Here we report that growth of both X4 and R5 strains of HIV-1 in activated peripheral blood T cells was enhanced by SLC. The enhancing effect of SLC was abrogated by pretreatment of cells with pertussis toxin, indicating the involvement of signaling via a receptor coupled with a Galphai class of G-protein. Furthermore, SLC was found to enhance the promoter activity of HIV-1 LTR. These results suggest that signaling via CCR7 has a strong positive effect on HIV growth. Thus, SLC and ELC may contribute to persistent infection of HIV in the secondary lymphoid tissues by promoting viral replication in activated T cells.
 ...
PMID:Enhanced HIV-1 replication by chemokines constitutively expressed in secondary lymphoid tissues. 1056 3

Chemokines have been hypothesized to contribute to the selectivity of lymphocyte trafficking not only as chemoattractants, but also by triggering integrin-dependent sticking (arrest) of circulating lymphocytes at venular sites of extravasation. We show that T cells roll on most Peyer's patch high endothelial venules (PP-HEVs), but preferentially arrest in segments displaying high levels of luminal secondary lymphoid tissue chemokine (SLC) (6Ckine, Exodus-2, thymus-derived chemotactic agent 4 [TCA-4]). This arrest is selectively inhibited by functional deletion (desensitization) of CC chemokine receptor 7 (CCR7), the receptor for SLC and for macrophage inflammatory protein (MIP)-3beta (EBV-induced molecule 1 ligand chemokine [ELC]), and does not occur in mutant DDD/1 mice that are deficient in these CCR7 ligands. In contrast, pertussis toxin-sensitive B cell sticking does not require SLC or MIP-3beta signaling, and occurs efficiently in SLC(low/-) HEV segments in wild-type mice, and in the SLC-negative HEVs of DDD/1 mice. Remarkably, sites of T and B cell firm adhesion are segregated in PPs, with HEVs supporting B cell accumulation concentrated in or near follicles, the target domain of most B cells entering PPs, whereas T cells preferentially accumulate in interfollicular HEVs. Our findings reveal a fundamental difference in signaling requirements for PP-HEV recognition by T and B cells, and describe an unexpected level of specialization of HEVs that may allow differential, segmental control of lymphocyte subset recruitment into functionally distinct lymphoid microenvironments in vivo.
 ...
PMID:The role of chemokines in the microenvironmental control of T versus B cell arrest in Peyer's patch high endothelial venules. 1062 Jun 6

Memory T cells (mTC) express multiple chemokine receptors (including CCR4 and CCR6) that may potentially be involved in their arrest on inflamed endothelia. Herein, we specifically addressed whether CCR6 is required for mTC to arrest on TNF-alpha-activated human dermal microvascular endothelial cells (HDMEC) in vitro under shear stress conditions. Recombinant liver and activation-regulated chemokine (LARC)/CCL20 (a CCR6 ligand) induced firm arrest of cutaneous lymphocyte Ag(+) mTC in a flow chamber system using purified substrates. Strikingly, desensitization of CCR6 with LARC, but not thymus and activation-regulated chemokine/CCL17 or secondary lymphoid tissue chemokine/CCL21, caused a 50-75% decrease (p < 0. 001) in arrest of mTC on HDMEC, which was indistinguishable from the reduction observed when total mTC were treated with pertussis toxin (p > 0.5). CCR6-depleted mTC also had a markedly reduced ability to arrest on HDMEC. Our results suggest that LARC production by activated endothelial cells and CCR6 expression by mTC may be critical components in the pertussis toxin-sensitive arrest of mTC on activated HDMEC.
 ...
PMID:Cutting edge: C-C chemokine receptor 6 is essential for arrest of a subset of memory T cells on activated dermal microvascular endothelial cells under physiologic flow conditions in vitro. 1112 Jul 83

We found that the murine breast cancer cell line 4T1 constitutively produced several chemokines capable of recruiting T cells. Additionally, supernatants from the tumor cell line mediated chemotaxis of T cells in a pertussis toxin-sensitive manner, indicating that these chemokines were functional. However, we also found an impaired chemotactic ability of splenic T cells in mice bearing these same tumors. The receptors for RANTES, MCP-1, and SLC were desensitized. Thus, the impaired chemotactic ability of T cells in tumor-bearing mice may explain why tumors that secrete chemokines grow progressively in a host.
 ...
PMID:Chemokine receptor desensitization in tumor-bearing mice. 1124 97

In this study, we investigate whether dendritic cells (DC), known to interact directly with T and B cells, might also contribute to the recruitment of B cells through the production of chemotactic factors. We found that B cells responded to several chemokines (CXCL12, CCL19, CCL20, and CCL21), which can be produced by DC upon activation. In addition, supernatant from DC (SNDC) potently and selectively attracted naive and memory B cells but not germinal center (GC) B cells or other lymphocytes (CD4(+), CD8(+) T cells or NK cells). Production of this activity was restricted to DC and was not increased following DC activation by LPS or CD40 ligand. Surprisingly, the B-cell chemotactic response to SNDC was insensitive to pertussis toxin treatment. In addition, the chemotactic factor(s) appeared resistant to protease digestion and highly sensitive to heat. This suggested that the DC chemotactic factor(s) is different from classical chemoattractants and does not involve G(alpha(i)) proteins on the responding B lymphocytes. It is interesting that SNDC was able to synergize with several chemokines to induce massive migration of B lymphocytes. These observations show that DC spontaneously produce factors that, alone or in cooperation with chemokines, specifically regulate B-cell migration, suggesting a key role of DC in the recruitment or localization of B lymphocytes within secondary lymphoid organs.
 ...
PMID:Selective attraction of naive and memory B cells by dendritic cells. 1159 Feb 1

Cognate interaction of chemokine receptor CCR7 on lymphocytes with its ligands CCL19 and CCL21 expressed on high endothelial venules (HEVs) is essential for effective migration of T and B cells across HEVs into secondary lymphoid organs. Plt mice, which lack expression of CCL19 and CCL21-ser, both ligands for CCR7 on HEVs, as well as CCR7-deficient mice, have a defective cell migration and reduced homing of lymphocytes. FTY720, a novel immunosuppressant, causes a reduction of lymphocytes in peripheral blood and tissues and their sequestration into lymphoid tissues. In this study we demonstrate that FTY720 rescues the homing defect in both CCR7(-/-) mice and plt mice. After FTY720 treatment, the number of CD4(+) and CD8(+) T cells as well as B cells in peripheral blood is reduced while pertussis toxin-sensitive homing into peripheral lymph nodes, mesenteric lymph node, and Peyer's patches is increased. Immunohistology demonstrates that FTY720 enables these cells to enter lymphoid tissue through HEVs. Thus, our data suggest an alternative G-alpha(i)-dependent, CCR7-CCL19/CCL21-independent mechanism for lymphocyte homing through HEVs which is strongly augmented in the presence of FTY720.
 ...
PMID:CC chemokine receptor 7-dependent and -independent pathways for lymphocyte homing: modulation by FTY720. 1174 87

In this study we examined the role of chemokines in regulating T lymphocyte transmigration across the lining high endothelial cells (HEC) of high endothelial venules (HEV). The roles played by CCL21 (SLC), CCL19 (MIP-3 beta, ELC) and CXCL12 (SDF-1) were assessed using an in vitro transendothelial migration culture system, which constitutively supports high levels of lymphocyte transmigration. We determined that transmigration of T lymphocytes across HEC is inhibitable by treatment of the T lymphocytes with pertussis toxin (PTX) (80% inhibition). This was attributed to blockade of Gi-protein coupled receptors of T lymphocytes, since a non-ADP-ribosylating form of PTX had no significant effect on transendothelial migration. Inhibition of Gi-protein-coupled receptors on the endothelium had no effect on T cell transmigration. Treatment of T lymphocytes with a desensitizing concentration of CXCL12 caused a 60% reduction in T lymphocyte migration across HEC, and the CXCR4 antagonist SDF-1P2G reduced transmigration by 40%. Desensitizing concentrations of CCL21 and CCL19 had no significant effects on T lymphocyte transendothelial migration. Homologous desensitization of T lymphocytes to each chemokine was confirmed in a transwell migration assay. An approximately 3-kb mRNA corresponding to rat SDF-1 beta was constitutively expressed in HEC and cell surface CXCL12 was detectable by enzyme-linked immunosorbent assay. Together, these findings support a pivotal role for HEC-expressed CXCL12 and its receptor on T cells in the regulation of T lymphocyte homing to lymph nodes.
 ...
PMID:Activation of pertussis toxin-sensitive CXCL12 (SDF-1) receptors mediates transendothelial migration of T lymphocytes across lymph node high endothelial cells. 1187 Jun 28

Migration of autoaggressive T cells across the blood-brain barrier (BBB) is critically involved in the initiation of experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. The direct involvement of chemokines in this process was suggested by our recent observation that G-protein-mediated signaling is required to promote adhesion strengthening of encephalitogenic T cells on BBB endothelium in vivo. To search for chemokines present at the BBB, we performed in situ hybridizations and immunohistochemistry and found expression of the lymphoid chemokines CCL19/ELC and CCL21/SLC in venules surrounded by inflammatory cells. Their expression was paralleled by the presence of their common receptor CCR7 in inflammatory cells in brain and spinal cord sections of mice afflicted with EAE. Encephalitogenic T cells showed surface expression of CCR7 and the alternative receptor for CCL21, CXCR3. They specifically chemotaxed towards both CCL19 or CCL21 in a concentration dependent and pertussis toxin-sensitive manner comparable to naive lymphocytes in vitro. Binding assays on frozen sections of EAE brains demonstrated a functional involvement of CCL19 and CCL21 in adhesion strengthening of encephalitogenic T lymphocytes to inflamed venules in the brain. Taken together our data suggest that the lymphoid chemokines CCL19 and CCL21 besides regulating lymphocyte homing to secondary lymphoid tissue are involved in T lymphocyte migration into the immunoprivileged central nervous system during immunosurveillance and chronic inflammation.
 ...
PMID:Functional expression of the lymphoid chemokines CCL19 (ELC) and CCL 21 (SLC) at the blood-brain barrier suggests their involvement in G-protein-dependent lymphocyte recruitment into the central nervous system during experimental autoimmune encephalomyelitis. 1220 25

We have studied the role of endothelins (ET-1, ET-2 and ET-3) and ET receptors (ET-RA and ET-RB) in the invasive capacity of breast tumor cells, which express ET-1 and ET-2 as well as ET-RA and ET-RB. Of five human breast tumor cell lines tested, all expressed mRNAs for ET-1, ET-2, and ET-RB. ET-RA mRNA was expressed by four of five tumor cell lines. Breast tumor cells migrated toward ET-1 and ET-2 but not toward ET-3. Chemotaxis involved signaling via both receptors, and a pertussis toxin-sensitive p42/p44 mitogen-activated protein kinase (MAPK)-mediated pathway that could be inhibited by MAPK kinase (MEK)1/2 antagonists. Chemotaxis toward ETs did not involve p38 or stress-activated protein kinase (SAPK)/Jun N-terminal kinase (JNK) and was not inhibited by hypoxia. Incubation of tumor cells with ET-2 also increased chemotaxis toward the chemokines CXCL12 and CCL21. As well as inducing chemotaxis of tumor cells, ET-1 and ET-2 increased tumor cell invasion through Matrigel. Furthermore, stimulation of macrophage/tumor cell cocultures with ETs led to increased matrix metalloproteinase (MMP)-2 and -9 production by macrophages and a marked increase in invasion of tumor cells. Antagonism of either ET-RA or ET-RB decreased the invasion seen in ET-stimulated cocultures, as did a broad-spectrum MMP inhibitor. Immunohistochemical staining of human breast tumor sections showed increased ET and ET receptor protein expression by tumor cells in invasive ductal carcinoma compared with normal breast tissue or ductal carcinoma in situ. Furthermore, tumor cell ET and receptor expression was stronger at the invasive margin of invasive ductal carcinomas, in the lymphovascular space, and in lymph node metastases. ET expression often colocalized with ET-RB expression in all neoplastic tissue indicating a possible autocrine action of ETs. We suggest that expression of ETs and their receptors by human breast tumors, particularly in conjunction with a high macrophage infiltrate, may have a role in the progression of breast cancer and the invasion of tumor cells.
 ...
PMID:A role for endothelin-2 and its receptors in breast tumor cell invasion. 1505 99

During embryonic development, T-lymphoid precursor cells colonize the thymus. Chemoattraction by the fetal thymus is thought to mediate T-precursor cell colonization. However, the molecules that attract T-precursor cells to the thymus remain unclear. By devising time-lapse visualization in culture, the present results show that alymphoid fetal thymus lobes attract T-precursor cells from fetal liver or fetal blood. CD4(-)CD8(-)CD25(-)CD44+ fetal thymocytes retained the activity to specifically re-enter the thymus. The attraction was predominantly due to I-A-expressing thymic epithelial cells and was mediated by pertussis toxin-sensitive G-protein signals. Among the chemokines produced by the fetal thymus, CCL21, CCL25, and CXCL12 could attract CD4(-)CD8(-)CD25(-)CD44+ fetal thymocytes. However, fetal thymus colonization was markedly diminished by neutralizing antibodies specific for CCL21 and CCL25, but not affected by anti-CXCL12 antibody. Fetal thymus colonization was partially defective in CCL21-deficient plt/plt mice and was further diminished by anti-CCL25 antibody. These results indicate that CCL21 is involved in the recruitment of T-cell precursors to the fetal thymus and suggest that the combination of CCL21 and CCL25 plays a major role in fetal thymus colonization.
 ...
PMID:The role of CCL21 in recruitment of T-precursor cells to fetal thymi. 1535 18


1 2 3 Next >>