Biomedical subjects

J Knop

Publications and source records attributed to J Knop.

At least 55 records · Page 3Linked to original sources

PubMed2000

Efficient transduction of mature CD83+ dendritic cells using recombinant adenovirus suppressed T cell stimulatory capacity.

We have developed a culture method for the foreign serum-free generation of highly immunostimulatory, CD83+ human dendritic cells (DC). In this study, we evaluated the feasibility and consequences of endogenously expressing antigens in mature DC using adenoviral vectors. Transduction of DC with Ad-EGFP demonstrated endogenous fluorescence in 50-85% of CD83+ DC. Ad-transduced DC stimulated the proliferation of allogeneic CD8+ and CD4+ T cells at low DC: T cell ratios. However, at high DC: T cell ratios the stimulatory capacity of Ad-transduced DC was suppressed. This immunosuppressive effect was confirmed by demonstrating that the stimulatory function of untreated DC could be suppressed in a dose-dependent manner by addition of Ad-transduced DC. Furthermore, transwell experiments suggested that direct cell contact was required. Taken together, our results demonstrate the feasibility of efficiently expressing antigens in CD83+ DC using adenoviruses. However, immunosuppressive effects must be considered and carefully studied before Ad-transduced DC are employed for clinical trials. Gene Therapy (2000) 7, 249-254.

Adenoviridae↗

PubMed2000

Therapeutic application of T cell receptor mimic peptides or cDNA in the treatment of T cell-mediated skin diseases.

An 8-amino acid peptide encoding a sequence of the transmembrane region of the T cell receptor alpha chain (TCR-alpha) was shown to inhibit T cell function by preventing functional assembly of the T cell receptor (mimic peptide). To avoid systemic immunosuppression by peptide application in vivo, we used a topical application of the peptide. In the system of murine contact sensitivity, topical application of the peptide inhibited the elicitation of contact sensitivity following application of a contact allergen in sensitized animals. Alternatively, when naked DNA encoding the peptide sequence was injected into skin before application of a contact allergen to sensitized animals, local immunosuppression was also observed. To investigate the effects of this peptide in humans, patients with psoriasis, atopic eczema, lichen planus, or contact dermatitis were treated topically with mimic peptide or control peptide. All patients except for one reported a marked improvement or cure of their skin disease following application of the TCR-alpha peptide, but not controls. These data indicate that TCR-alpha peptide or cDNA treatment might be a proper treatment for human T cell-mediated dermatoses substituting for corticosteroids.

Allergens↗

PubMed2000

Expression of the actin-bundling protein fascin in cultured human dendritic cells correlates with dendritic morphology and cell differentiation.

Dendritic cells are key players of the immune system as they efficiently induce primary immune responses by activating naive T cells. We generated human dendritic cells from CD14+ blood precursors and investigated expression of the actin-bundling protein fascin during maturation by western blotting, immunofluorescence, and cytofluorometry. Cells obtained by culture of CD14+ blood precursors in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4, which were only weakly positive for the maturation marker CD83, expressed low amounts of fascin. Addition of a cytokine cocktail including tumor necrosis factor alpha, interleukin-1beta, interleukin-6, and prostaglandin E2 induced maturation of the cells and enhanced fascin expression in parallel with CD83 expression. Isolated mature CD83+ cells displayed especially high fascin levels on western blots, as did gated CD83+ dendritic cells in cytofluorometry. Dendritic cells generated from CD34+ blood precursors expressed high levels of fascin as well. Confocal microscopy revealed that location of fascin within the cell was restricted to the area of the submembranous actin cytoskeleton and to the dendritic processes. Suppression experiments using antisense constructs of fascin hint at a retarded morphologic maturation of dendritic cells, supporting the view that fascin expression is pivotal for dendrite formation. Our data suggest that fascin could serve as a marker molecule to monitor the maturation state of in vitro generated dendritic cells for use in clinical trials.

Actins↗

PubMed2000

Fetal calf serum-free generation of functionally active murine dendritic cells suitable for in vivo therapeutic approaches.

UNLABELLED: Standard protocols to generate mouse dendritic cells (DC) generally use culture medium supplemented with fetal calf serum; however, reinjection in vivo of DC cultured in fetal calf serum results in priming to xenogeneic proteins that clearly limits the use of such DC. We therefore established a fetal calf serum-free culture system for the generation of murine DC from bone marrow precursors. DC can be generated fetal calf serum-free using RPMI supplemented with 1.5% syngeneic mouse serum. Although the yield of DC grown under fetal calf serum-free conditions was somewhat lower than that of the standard culture, large numbers of DC could be generated without the exposure to xenogeneic proteins. The yield of fetal calf serum-free cultured DC was further enhanced by addition of the proinflammatory cytokines TNF-alpha and IL-1beta with the combination resulting in up to 10% more DC. Phenotypically, CD11c + DC cultured fetal calf serum-free homogenously coexpressed the DC-specific molecule DEC-205 as well as the costimulatory molecules CD40, CD80, and CD86. In contrast, only a subpopulation of the CD11c + DC cultured in fetal calf serum-containing medium coexpressed these molecules. Functionally, fetal calf serum-free DC showed strong stimulatory capacity for naïve allogeneic CD4 + and CD8 + T cells. Importantly, fetal calf serum-free DC showed spontaneous in vivo migratory activity. Moreover, 5 x 105 subcutaneously injected TNBS-conjugated fetal calf serum-free DC were able to mediate contact sensitivity. Furthermore, the intravenous or subcutaneous injection of a single dose of 5 x 105 OVA-pulsed fetal calf serum-free DC resulted in the induction of an OVA-specific immune response in naïve TCR transgenic animals. Thus DC cultured under fetal calf serum-free conditions are suitable instruments for in vivo therapeutic approaches, especially in autoimmune models. KEYWORDS: DC vaccines/dendritic cell development/fetal calf serum-free culture conditions for DC/in vivo therapeutic DC approaches.

Animals↗

PubMed2000

Deficient cytokine response of human allergen-specific T lymphocytes from humanized SCID mice and reconstitution by professional antigen-presenting cells.

BACKGROUND: Hu-PBL-SCID mice generated by the transfer of PBMCs from atopic individuals may provide a physiologic in vivo model for investigating human responses to allergens and potential approaches toward immunotherapy. OBJECTIVE: This study was undertaken to investigate the functional activity and cytokine profile of human allergen-reactive T lymphocytes isolated from hu-PBL-SCID mice. METHODS: PBMCs from allergic individuals were coinjected with allergen into SCID mice. Human lymphocyte migration and phenotype were established by reverse transcription-PCR and immunohistochemistry, IgE levels in sera were determined, and the frequency of allergen-reactive cytokine-producing T lymphocytes was established. RESULTS: After immunization with allergen, specific IgE levels in hu-PBL-SCID sera were comparable with levels in donor sera. Although the majority of lymphocytes remained in the peritoneum, significant numbers of T lymphocytes were located in the spleen, where human IL-4, IL-5, and IFN-gamma messenger RNA expression was detected after stimulation with PHA and phorbol myristate acetate. Failure to induce cytokine production by human T lymphocytes isolated from the peritoneum and spleen of hu-PBL-SCID mice by allergen was reversed by stimulating with allergen in the presence of exogenously added IL-2 and antigen-presenting cells (APC), particularly CD14(+) monocytes. Under these conditions, allergen-reactive T cells expressed a T(H)2-like phenotype. CONCLUSIONS: These data suggest that, after initial activation and induction of antibody production, human T lymphocytes enter a state of unresponsiveness, arising from a loss of human professional APC, in hu-PBL-SCID mice. The use of hu-PBL-SCID mouse models in studies on therapeutic approaches for allergy may benefit from the additional transfer of human professional APC.

Allergens↗

PubMed2000

Comparison of allergen-stimulated dendritic cells from atopic and nonatopic donors dissecting their effect on autologous naive and memory T helper cells of such donors.

BACKGROUND: Because of their production of IL-12, mature dendritic cells (DC) are potent inducers of T(H)1 responses. However, recent reports have demonstrated that DCs can also induce T(H)2 differentiation. OBJECTIVE: In the current study we investigated which immune response is induced by DCs in naive CD45RA(+) or memory CD45R0(+) CD4(+) T cells from atopic individuals (patients with grass pollen, birch pollen, or house dust mite allergy) compared with nonatopic control subjects. METHODS: Immature DCs, generated from peripheral blood monocytes from atopic and nonatopic donors, were pulsed with the respective allergen and fully matured. Then the mature DCs were cocultured in vitro with autologous naive (CD45RA(+)) and memory (CD45R0(+)) CD4(+) T cells and cytokine and IgE production were measured by ELISA. RESULTS: After the second restimulation with allergen-pulsed DCs, naive as well as memory autologous CD4(+) T cells from atopic but not from nonatopic donors showed an enhanced production of the T(H)2-type cytokines IL-4, IL-5, and IL-10, resulting in an increased IgE production, whereas IFN-gamma production and proliferation were not different. IL-12 production and surface marker expression of DCs derived from atopic and nonatopic donors did not differ and addition of neutralizing anti-IL-12 mAbs did not increase IL-4 but diminished IFN-gamma production. CONCLUSION: These data indicate that mature DCs are able to induce naive and activate allergen-specific T helper cells to produce T(H)2 cytokines if the T cells are derived from atopic donors. This phenomenon is not due to diminished IL-12 production by DCs of atopic donors.

Allergens↗

PubMed2000

T cell receptor mimic peptides and their potential application in T-cell-mediated disease.

BACKGROUND: A T cell receptor (TCR) peptide was designed that mimics the intramembranous amino acid sequence of the TCR chain. Prior studies had shown that this mimic peptide would inhibit TCR signaling. This study was designed to investigate the use of this mimic peptide for the treatment of T-cell-mediated skin diseases. METHODS: Synthesized mimic peptides were first tested for their T-cell-inhibitory effect in proliferation assays. Afterwards, mimic peptides were applied to murine ear skin prior to application of a contact allergen and tested for their inhibitory effect in the model of murine allergic contact sensitivity. The effect of epicutaneous treatment with the peptide was also tested on patients with T-cell-mediated skin disease. RESULTS: Mimic peptide potently inhibited proliferation of CD4(+) and CD8(+) T cells when added to allogeneic proliferation assays using dendritic cells as antigen-presenting cells (APCs). Suppression of the proliferative capacity could be overcome by addition of an anti-CD3 monoclonal antibody. When applied to murine ear skin prior to application of a contact allergen, mimic peptide efficiently blocked ear swelling responses in mice. In humans, application of mimic peptide for the treatment of various diseases resulted in amelioration or even cure in patients suffering from atopic dermatitis, psoriasis or lichen planus. CONCLUSIONS: TCR mimic peptide efficiently abrogates T-cell-mediated immune responses in mice and man in vitro and in vivo. The potential immunosuppressive effect of the drug is discussed.

Amino Acid Sequence↗

PubMed1999

Involvement of reactive oxygen species in TNF-alpha mediated activation of the transcription factor NF-kappaB in canine dermal fibroblasts.

The cytokine tumor necrosis factor-alpha (TNF-alpha) plays a major role in inflammatory and immune-pathological reactions of the skin. With respect to a possible therapeutic modulation of TNF-alpha mediated activation of Nuclear Factor-kappa B (NF-kappaB) in canine cutaneous inflammation, we investigated the role of NF-kappaB and the involvement of reactive oxygen species (ROS) in the TNF-alpha signalling pathway in dermal fibroblasts of the dog. TNF-alpha treatment resulted in the activation of NF-kappaB as assessed by electrophoretic mobility shift assay (EMSA). Additionally, NF-kappaB translocation was induced with butylhydroperoxide and antimycin A, but not with hydrogen peroxide. TNF-alpha stimulated NF-kappaB activation was partially inhibited by preincubation with the antioxidants alpha-lipoic acid and butylated hydroxyanisol (BHA). No superoxide generation following TNF-alpha stimulation could be detected in the supernatant of canine fibroblasts with the superoxide dismutase-inhibitable cytochrome c reduction test. In contrast, production of TNF-alpha dependent intracellular hydrogen peroxide, the dismutation product of the superoxide radical, was demonstrated spectroscopically by formation of electron dense cerium-hydroperoxide precipitates. With electron energy loss spectroscopy (EELS) significant cerium deposits were detected in the mitochondria, the endoplasmatic reticulum, the cytosol and to a lesser extent on the plasma membrane of canine fibroblasts indicating multiple hydrogen peroxide production sites. Peroxides, therefore, possibly play an important part in the redox-sensitive pathway of TNF-alpha dependent NF-kappaB activation in canine skin. An adjunctive therapy with appropriate antioxidants modulating NF-kappaB overactivation in cutaneous inflammation in the dog is promising.

Animals↗

PubMed1999

Effects of IL-1 receptor-associated kinase (IRAK) expression on IL-1 signaling are independent of its kinase activity.

Interleukin-1 (IL-1) stimulates the association of the IL-1 receptor-associated protein kinase (IRAK) with the heterodimer of IL-IRI and IL-IRAcP via the adapter protein MyD88. In the receptor complex IRAK becomes heavily phosphorylated and concomitantly activated. Here we show that overexpression of a kinase-inactive mutant of IRAK (K239S) inhibits neither IL-1-stimulated activation of the transcription factor NF-kappaB, nor that of the c-Jun N-terminal kinase nor IL-2 production in murine EL-4 cells, but enhances these effects in a manner comparable to wild type IRAK. This strongly suggests that the intrinsic kinase activity is not required for downstream signaling via IRAK.

Animals↗

PubMed1999

Interleukin-10-treated human dendritic cells induce a melanoma-antigen-specific anergy in CD8(+) T cells resulting in a failure to lyse tumor cells.

Dendritic cells (DC) are critically involved in the initiation of primary immune processes, including tumor rejection. In our study, we investigated the effect of interleukin-10 (IL-10)-treated human DC on the properties of CD8(+) T cells that are known to be essential for the destruction of tumor cells. We show that IL-10-pretreatment of DC not only reduces their allostimulatory capacity, but also induces a state of alloantigen-specific anergy in both primed and naive (CD45RA+) CD8(+) T cells. To investigate the influence of IL-10-treated DC on melanoma-associated antigen-specific T cells, we generated a tyrosinase-specific CD8(+) T-cell line by several rounds of stimulation with the specific antigen. After coculture with IL-10-treated DC, restimulation of the T-cell line with untreated, antigen-pulsed DC demonstrated peptide-specific anergy in the tyrosinase-specific T cells. Addition of IL-2 to the anergic T cells reversed the state of both alloantigen- or peptide-specific anergy. In contrast to optimally stimulated CD8(+) T cells, anergic tyrosinase-specific CD8(+) T cells, after coculture with peptide-pulsed IL-10-treated DC, failed to lyse an HLA-A2-positive and tyrosinase-expressing melanoma cell line. Thus, our data demonstrate that IL-10-treated DC induce an antigen-specific anergy in cytotoxic CD8(+) T cells, a process that might be a mechanism of tumors to inhibit immune surveillance by converting DC into tolerogenic antigen-presenting cells.

Antigen Presentation↗

PubMed1999

Mycophenolate is effective in the treatment of pemphigus vulgaris.

BACKGROUND: Pemphigus vulgaris is a potentially life-threatening autoimmune disease. Although combination therapies with prednisone and azathioprine are usually effective in controlling the disease, some patients either do not respond to this treatment or show early relapses. OBJECTIVE: To find out whether mycophenolate mofetil would be an effective drug in controlling pemphigus vulgaris in patients who failed initial treatment with azathioprine and prednisone. RESULTS: Twelve patients who were initially diagnosed as having pemphigus vulgaris and had relapsed while undergoing treatment with azathioprine (1.5-2 mg/kg of body weight) and prednisolone (2 mg/kg of body weight) subsequently received combination therapy with mycophenolate mofetil (2 x 1 g/d) and prednisolone (2 mg/kg of body weight per day). Eleven of the 12 patients responded to therapy and showed no relapse of their disease even after tapering of the steroid dose. One patient did not respond. Toxic effects were low with only mild gastrointestinal symptoms in 5 patients and mild lymphopenia (World Health Organization grade I) in 9 patients. During the 9- to 12-month follow-up, none of the 11 patients showed reappearance of pemphigus lesions. CONCLUSION: Treatment of pemphigus vulgaris with mycophenolate is a safe and effective treatment.

Adult↗

PubMed1999

[Decreased rate of progression and induction of tumor-specific immune response by adjuvant immunotherapy in stage IV melanoma].

Stage IV melanoma is still a disease with poor prognosis. Although modern chemo- or chemoimmunotherapies give high response rates in stage IV patients, remissions are usually followed by fast relapses. In order to avoid early relapses after chemotherapy, patients with stage IV disease and either stable disease or partial or complete remission following therapy were treated with 9 million IU IFN alpha subcutaneously 5 times weekly and 6 million IU IL-2 subcutaneously twice weekly. Compared with untreated controls, the rate of progression in the treatment group was reduced from 95% to 35%. Also, time to progression was significantly prolonged. Median survival times in the control group were 25 weeks, whereas median survival time in the treatment group has not yet been reached. Furthermore, TNF-ELISPOT assays showed a significant increase in MAGE-3 reactive cytotoxic T-cells in the treatment, but not in the control group. Thus, immunotherapy in stage IV disease seems to prolong survival in melanoma patients.

Adult↗

PubMed1999

Detection of increased tyrosine phosphorylation in murine Langerhans cells after stimulation with contact sensitizers.

The signalling pathways in epidermal Langerhans cells (LC) during activation by contact sensitizers are poorly understood. Recently, we have described an increased phosphorylation of tyrosine residues in human MHC class II-positive cells in vitro following stimulation with contact sensitizers. In the study reported here the formation of phosphotyrosine (p-tyr) in murine epidermal LC upon stimulation with contact sensitizers was examined. By the use of a flow cytometric technique a significant increase in p-tyr was demonstrated in LC stimulated in vitro with the strong contact sensitizers TNCB (2,4,6-trinitro-chlorobenzene) and MCI/MI (5-chloro-2-methylisothiazolinone plus 2-methylisothiazolinone) but not after treatment with the irritants sodium lauryl sulphate or benzoic acid. The protein tyrosine kinase inhibitors genistein and tyrphostin A9, but not tyrphostin AG 1288, were able to block this process significantly. Similar results were obtained using the LC-like dendritic cell line XS52. In addition, Western blot analysis on XS52 cells revealed a selective phosphorylation of two protein bands with a molecular weight between 50 and 60 kDa following stimulation with TNCB. These results demonstrate that contact sensitizers induce an increased phosphorylation of tyrosine residues in murine LC and can be used as the basis for in vivo studies using inhibitors for signal transduction pathways for prevention of primary sensitization to contact sensitizers.

Animals↗

PubMed1999

Allergen-specific immune deviation from a TH2 to a TH1 response induced by dendritic cells and collagen type I.

BACKGROUND: Atopy and IgE production are associated with enhanced allergen-specific T(H)2 responses. Therefore a causative treatment may result from the deviation of this T(H)2-dominated immune response toward a T(H)1 response. OBJECTIVE: This study was carried out to analyze whether dendritic cells, the most potent antigen-presenting cells that are also known to induce antigen-specific T(H)1 responses, are suitable for therapy of atopic diseases by shifting the allergen-specific T(H)2 response toward a T(H)1 response. METHODS: Monocyte-derived dendritic cells were used to present allergens in vitro to autologous CD4(+) T cells of allergic persons. Because collagen type I activates dendritic cells and enhances the secretion of IL-12, we performed allergen presentation assays also in the presence of collagen type I. RESULTS: After stimulation with allergen-pulsed dendritic cells the production of IFN-gamma as well as that of IL-4 and IL-5 by CD4(+) T cells was enhanced. In the presence of collagen type I, however, a significant shift toward a T(H)1 response with increased production of IFN-gamma and a decreased production of IL-5 could be observed. When T cells were stimulated directly with anti-CD3 and anti-CD28 in the absence of antigen-presenting cells, it was demonstrated that collagen type I also exerted a direct effect on T cells, increasing their IFN-gamma production. CONCLUSION: These data indicate that collagen type I influences dendritic cells as well as T cells in a way that a shift in cytokine production results in a T(H)1 response even in already-sensitized atopic individuals.

Allergens↗

PubMed1999

Signals involved in the early TH1/TH2 polarization of an immune response depending on the type of antigen.

BACKGROUND: The early production of distinct cytokines by epidermal cells (ECs) in response to antigen exposure may govern the development of TH1 -like immune responses, such as contact sensitivity, or TH2 -like immune responses, such as IgE-dependent allergies of the immediate type, depending on the type of antigen. OBJECTIVE: The aim of this study was to compare the signals induced by protein allergens with those induced by haptens in ECs and subsequently in local draining lymph node cells (LNCs) or splenocytes. METHODS: BALB/c mice were primed in vivo with the protein allergens ovalbumin or birch pollen or the haptens 2, 4-dinitrofluorobenzene or trinitrochlorbenzene, respectively, and cytokine and immunoglobulin secretions of responding splenocytes were measured by ELISA after in vitro coculture with ECs. Induction of cytokine mRNA expression in ECs and LNCs was analyzed by reverse transcriptase-PCR. RESULTS: In the presence of protein allergens, ECs enhance the induction of a TH2 immune response (IL-4 and IgE production of splenocytes), whereas a TH1 immune response (IFN-gamma and IgG2a production) was only induced in the context of haptens. Heat inactivation of ovalbumin did not diminish the development of a TH2 immune response. One direct effect of antigen on ECs was the earlier expression of IL-10 mRNA after stimulation with protein allergens (30 minutes) than with haptens (2 hours) in vitro. By using an in vivo approach, sensitization of the skin with trinitrochlorbenzene, but not with ovalbumin, resulted in an early induction of IL-1beta, IL-12p40, and IFN-gamma mRNA in LNCs, whereas IL-18 was induced by both. CONCLUSION: These data indicate that the type of antigen strongly influences the type of immune response by eliciting distinct signals already in the epithelium.

Allergens↗

PubMed1999

Decreased release of histamine and sulfidoleukotrienes by human peripheral blood leukocytes after wasp venom immunotherapy is partially due to induction of IL-10 and IFN-gamma production of T cells.

BACKGROUND: Recent studies provide evidence that venom immunotherapy (VIT) alters the pattern of cytokine production by inducing an allergen-specific T-cell shift in cytokine expression from TH2 (IL-4, IL-5) to TH1 (IFN-gamma) cytokines and also inducing the production of IL-10. OBJECTIVE: This study was carried out to analyze whether these changes in cytokine production of T cells already observed 1 week after the initiation of VIT in subjects with wasp venom allergy also influence the reactivity of effector cells, such as mast cells and basophils. METHODS: All subjects included in this study had a history of severe systemic allergic reactions to wasp stings and positive skin test responses with venom and venom-specific IgE in the sera. Peripheral blood leukocytes were isolated before and after the initiation of VIT (rush therapy reaching a maintenance dose of 100 microg venom injected subcutaneously within 1 week) and preincubated with or without addition of IL-10, IFN-gamma, IL-10 + IFN-gamma, anti-IL-10, or anti-IFN-gamma. After stimulation with wasp venom, histamine and sulfidoleukotriene release were assessed by ELISA and compared with spontaneous release and total histamine content. RESULTS: After the induction of VIT, venom-induced absolute and relative histamine and sulfidoleukotriene release were reduced. This was at least partially due to the induction of IFN-gamma and IL-10 production, because (1) neutralization of IL-10 and IFN-gamma by mAbs partially restored the release after the initiation of VIT and (2) the addition of exogenous IFN-gamma and IL-10 caused a statistically significant diminution of the venom-induced histamine and sulfidoleukotriene release before VIT. Depletion of CD2(+) T cells also restored the releasability after VIT. CONCLUSION: These data indicate that T cells (producing IL-10 and IFN-gamma after VIT) play a key role for the inhibition of histamine and sulfidoleukotriene release of effector cells.

Antibodies, Monoclonal↗

PubMed1999

Mouse langerhans cells differentially express an activated T cell-attracting CC chemokine.

Epidermal Langerhans cells represent an immature population of dendritic cells, not yet able to prime naïve T cells. Following in vitro culture Langerhans cells mature into potent immunostimulatory cells. We constructed a representative cDNA library of in vitro matured murine Langerhans cells. Applying a differential screening procedure 112 differentially expressed cDNA clones were isolated. Thirty-six clones represented cDNA fragments of the same gene, identifying it to be the most actively expressed gene induced in maturing Langerhans cells. A full-length cDNA was sequenced completely. The open reading frame codes for a protein of 92 amino acids containing a leader peptide of 24 amino acids, yielding a mature protein of 7.8 kDa molecular weight. Database searches revealed 99.4% sequence identity on the nucleotide level to the recently described mouse CC chemokine ABCD-1, as well as 74% sequence identity to the human CC chemokine, the macrophage-derived chemokine/stimulated T cell chemotactic protein. Expression was analyzed by reverse transcriptase-polymerase chain reaction on a large panel of cell types. Unlike the macrophage-derived chemokine, expression was not detected in macrophages stimulated by various cytokines. Expression is restricted to cultured Langerhans cells, in vitro cultured dendritic cells, and lipopolysaccharide-activated B cells. Recombinant protein was expressed in the yeast Pichia pastoris and purified to homogeneity. Whereas no chemotactic activity was observed in chemotaxis assays for naïve T cells, B cells, cultured dendritic cells, and Langerhans cells, a strong chemoattractant activity was exerted on activated T cells. Thus, production of this chemokine by dendritic cells may be essential for the establishment and amplification of T cell responses.

Amino Acid Sequence↗

PubMed1999

Breast-feeding and alcoholism: the Trotter hypothesis.

OBJECTIVE: The authors' goal was to determine whether early termination of breast-feeding contributes to later alcohol dependence, as proposed more than 200 years ago by the British physician Thomas Trotter. METHOD: In 1959-1961, a multiple-specialty group of physicians studied 9, 182 consecutive deliveries in a Danish hospital, obtaining data about prepartum and postpartum variables. The present study concentrates on perinatal variables obtained from 200 of the original babies who participated in a 30-year high-risk follow-up study of the antecedents of alcoholism. RESULTS: Of the 27 men who were diagnosed as alcohol dependent at age 30, 13 (48%) came from the group weaned from the breast before the age of 3 weeks; only 33 (19%) of the 173 non-alcohol-dependent subjects came from the early weaning group. When challenged by other perinatal variables in a multiple regression analysis, early weaning significantly contributed to the prediction of the severity of alcoholism at age 30. CONCLUSIONS: The data support the hypothesis that early weaning may be associated with a greater risk of alcohol dependence later in life.

Adult↗