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PubMed2004

Evaluation of recombinant and native timothy pollen (rPhl p 1, 2, 5, 6, 7, 11, 12 and nPhl p 4)- specific IgG4 antibodies induced by subcutaneous immunotherapy with timothy pollen extract in allergic patients.

BACKGROUND: Allergen immunotherapy is a widely accepted treatment for IgE-mediated allergies. The evaluation of immunotherapy-induced IgG4 antibodies based on allergen extract is questionable because the amount of allergen-extract-specific IgG4 to individual disease-eliciting allergens cannot be determined using crude allergen extracts. In this study, we examined the specific IgE and IgG4 serum binding profiles to individual Phleum pratense allergens in grass-pollen-sensitive patients who had received grass-pollen-specific immunotherapy (SIT). METHODS: The study included 33 patients from North-West Italy. All suffered from seasonal rhinoconjunctivitis and/or asthma. A modified "cluster" regimen of injections of a standardized aluminium-adsorbed P.pratense extract, with once-weekly visits and 10 injections for 5 weeks followed by 3 weeks of maintenance injections was instituted. Patients' sera were analyzed for specific IgE and IgG4 reactivity to individual P. pratense allergens (recombinant Phl p 1, Phl p 2, Phl p 5, Phl p 6, Phl p 7, Phl p 11, Phl p12 and native Phl p 4) and natural P. pratense extract using the Pharmacia CAP system. RESULTS: IgE reactivities to new allergen components were not detected by CAP in treated patients after 15 weeks and a cumulative dose of approximately 65 microg of the major allergen Phl p 5. Patients lacking specific IgE reactivity towards individual allergens at the start of SIT did not produce significant levels of specific serum IgG4 to serum IgE-negative allergens. On the other hand, an increase in specific IgG4 only to allergens to which patients were previously sensitized was observed. Significant increases in specific IgG4 levels to rPhl p 1 (p < 0.05), 2 (p < (0.01), 5 (p < 0.0001), 6 (p < 0.0001), 7 (p < 0.05), 11 (p < 0.05) and nPhl p 4 (p < 0.01) were observed after P. pratense extract immunotherapy. No significant rPhl p 12-specific IgG4 antibody increase was documented after treatment. CONCLUSION: These findings suggest that Phl p 12 was underrepresented in the extract used, as indicated by the low specific IgG4 response induced by this grass-pollen-specific vaccine. Thus, the simple detection of specific serum IgG4 antibodies a few weeks after the start of SIT could represent a valuable tool to estimate the presence of relevant allergens in a given immunotherapeutic allergen extract.

Adolescent↗
PubMed1982

Altered function and membrane properties of lymphocytic leukemia cells. Correlation with clinical stage of disease.

Lymphocytes from the peripheral blood of patients with chronic lymphocytic leukemia (CLL) were examined for the presence of several recognized surface receptors [immunoglobulins, C3 component of complement, and concanavalin A (Con A)] and for structural changes in membrane distribution and dynamics, such as mobility and capping. There appeared to be a general decrease in the mobility of the various receptors on the surface membranes of CLL cells as compared with normal lymphocytes. Although C3 receptors were present on the majority of CLL cells, only a small proportion of the cells formed EAC rosettes. The response to phytohemagglutinin (PHA), Con A and pokeweed mitogen (PWM) confirmed previous observations that CLL cells respond poorly to the B cell mitogen, PWM, and that this response is significantly lower than that to the T cell mitogens, PHA and Con A. The decrease in response to all three mitogens seemed to correlate with the clinical stage of the disease, and it appears that Stage II cases may constitute a heterogeneous group of patients in this respect. A differential response to reduced concentrations of PHA was observed in CLL lymphocytes, but not with normal cells. The data concerning B and T cell function in CLL cells, as determined by the transformation and rosetting capacity of these cells, suggest a general decrease in function, which apparently deteriorates with progression of the disease.

Cell Membrane↗
PubMed1987

Comparison of blocking effects of monoclonal antibodies anti-MO1-alpha and anti-LFA1-alpha on human neutrophil functions.

In order to analyse the role of LFA1 and MO1 on neutrophil functions, the blocking effects of two monoclonal antibodies (MAb), one (anti-MO1) recognizing an epitope of the MO1-alpha chain and the other (25.31) an epitope of the LFA1-alpha chain, were measured. Adherence of 51Cr-labelled control neutrophils was 66 + 8% (mean +/- 1 SD) on plastic nuclon plates; this figure decreased to 33 +/- 5% and 23 +/- 6% of control adherence when the neutrophils had been pretreated with anti-LFA1-alpha (anti-alpha L) and anti-MO1-alpha (anti-alpha M), respectively. On another support (plastic culture chambers), 84 +/- 6% of control neutrophils adhered and the adherence of neutrophils pretreated with anti-alpha L or anti-alpha M was 10% and 43% of the control figure, respectively. These results show that adherence of neutrophils is dependent upon the plastic used. Moreover, inhibition of adhesion by the two MAbs was also dependent upon the support used for the assay, suggesting that MO1 and LFA1 may be surface proteins with different specificities. Both antigens capped upon adhesion, while they were randomly distributed in resting neutrophils. Anti-alpha L inhibited (congruent to 50%) locomotion more than did anti-alpha M (congruent to 25%), without altering chemoattractant-induced shape changes. These results suggest that the two MAbs inhibit chemokinesis but not chemotaxis. Many other adherence-associated functions, such as ingestion of opsonized Klebsiella pneumoniae, and cytotoxicity towards K/562 cells were decreased more by anti-alpha L than by anti-alpha M. In contrast, chemiluminescence and iodination induced by opsonized zymosan were inhibited more by anti-alpha M than by anti-alpha L. Degranulation induced by zymosan or opsonized zymosan was altered by anti-alpha M only, and this alteration involved azurophilic and not specific granules. Chemiluminescence induced by phorbol myristate acetate was inhibited to a greater extent by anti-alpha M than by anti-alpha L, while degranulation induced by phorbol myristate acetate was not altered by either of the two Mabs.

Adult↗
PubMed2003

Specific immunotherapy for severe latex allergy.

We studied 4 patients (3 adult females + 13y old boy) with latex allergy. All patients had anaphylaxis related with latex and oral-latex-fruit syndrome. All 3 females had severe symptoms in the workplace. The boy had spina bifida with 9 previous surgeries and needed further surgical interventions. Positive skin prick tests (SPT), the presence of serum latex specific IgE (CAP-RAST, Pharmacia-Upjohn, Sweden- class 3 in the 3 females and class 4 in the boy) demonstrated the sensitisation. All 4 patients were treated with specific immunotherapy (SIT) with aqueous extract (ALK-ALK-ABELLO SA, Spain) administered subcutaneously at the hospital, by a modified rush schedule. A maintenance dose (MD) of 0.35_g protein was established according to the magnitude of local reactions (LRs). In one patient a higher dose induced the appearance of a systemic reaction (SR) 40 min after administration, which promptly remitted with treatment. After reaching MD, all 3 females remained assymptomatic at workplace. A challenge test with latex gloves was performed. Two months after MD was reached 2 females had no symptoms and one other had mild symptoms of rhinoconjunctivitis. The boy was subjected to a surgical intervention with no allergic reaction. We also observed a reduction on skin reactivity to latex in all patients by prick tests. We consider SIT with latex to be highly effective, safe and well tolerated provided we use this dose of the allergenic extract.

Adolescent↗
PubMed2003

An orally active Amazonian plant extract (BIRM) inhibits prostate cancer growth and metastasis.

PURPOSE: Poor efficacy of conventional chemotherapeutic drugs against metastatic hormone-refractory prostate cancer (CaP) drives patients to try "alternative medicine". The antitumor activity of one such agent, "BIRM" (biological immune response modulator; "Simple Ecuadorian Oral Solution: an extract of an Amazonian plant"), was characterized in vitro and in vivo using established CaP cell lines and a tumor model. METHODS: The cytotoxicity of BIRM in four human and one rat CaP cell line was evaluated using cell proliferation-inhibition and clonogenic survival assays. BIRM-induced apoptosis, alterations in cell cycle phase progression and inhibition of the extracellular matrix-degrading enzyme hyaluronidase were also investigated in these cells. The in vivo efficacy of BIRM was evaluated in rats with subcutaneous tumor implants of Dunning EGFP-MAT LyLu cells. The active species in BIRM were characterized by gel filtration chromatography. RESULTS: BIRM inhibited cell proliferation and clonogenic growth of the CaP cells (IC(50) about 8.0 microl/ml). It increased cell accumulation in the G(0)/G(1) phase by 33.8% and decreased the proportion of cells in S phase by 54.6%. Apoptotic cell death in BIRM-treated cells was associated with activation of cell death-associated caspases. BIRM inhibited the activity of hyaluronidase, a hyaluronic acid-degrading enzyme, at 1 microl/ml. Treatment of MAT LyLu tumor-bearing rats with BIRM by oral gavage resulted in a significant decrease in tumor incidence (50%), tumor growth rate (18.6+/-1.3 days for 1 cc tumor growth in control rats and 25.7+/-2.6 days in BIRM-treated rats), and only one out of six BIRM-treated rats versus four out of six in the control group developed lung metastasis. Three active ingredients in BIRM with a relative molecular mass (Mr) of >or=3500 were identified by ultracentrifugation and gel filtration chromatography and were found to be resistant to proteinase and heat (100 degrees C). CONCLUSION: The plant extract BIRM contains antitumor compounds of Mr >or=3500 with potent antiproliferative activity in vitro and in vivo against prostate cancer cells.

Administration, Oral↗
PubMed2004

The basophil activation test in wasp venom allergy: sensitivity, specificity and monitoring specific immunotherapy.

BACKGROUND: As in vitro diagnosis of wasp venom sensitization by specific serum IgE has a sensitivity of only 60-80%, additional in vitro tests are desirable. Basophil activation is associated with the expression of CD63 and its measurement has been proposed as a novel in vitro test for immediate-type allergy. Furthermore, to date, no in vitro test exists to monitor successful specific immunotherapy (SIT) with wasp venom. Therefore, the potentially harmful sting challenge is still recommended. OBJECTIVE: We compared the CD63-based basophil activation test (BAT) in the diagnosis of wasp venom allergy with skin tests and measurement of specific IgE. Furthermore, we investigated whether BAT can predict the outcome of the sting challenge in patients on SIT. METHODS: Fifty patients with a systemic reaction caused by a wasp sting and 20 controls were studied. Intracutaneous tests were performed with wasp and bee venom in the suspected allergics. Specific IgE was determined by the CAP-FEIA method and basophil activation by flow cytometry upon double staining with anti-IgE/anti-CD63 mAb. Twenty-five patients were sting challenged 6 months after starting SIT and the BAT was repeated before challenge. RESULTS: Sensitivity of the intracutaneous tests, specific IgE and BAT was 100, 76, and 92%, respectively. Specificity of specific IgE and the BAT was 85 and 80%, respectively. The cut-off for a positive BAT was 15% CD63+ basophils. There was a positive correlation between IgE reactivity to wasp venom and the number of CD63+ basophils (r = 0.65). Although no patient had a systemic reaction upon sting challenge, in most subjects basophil activation did not decrease when compared with the BAT before SIT. CONCLUSIONS: Quantitation of basophil activation by CD63 expression is a valuable new in vitro method for diagnosis of allergy to hymenopteran venoms. The CD63-based BAT is a helpful tool for the complementation of routine diagnostic tests such as specific IgE as it increases sensitivity of in vitro detection of sensitization. However, this in vitro method does not offer an alternative to the sting challenge in monitoring successful SIT.

Adolescent↗
PubMed1976

Immunoglobulin M receptors on memory cells of immunoglobulin G antibody-forming cell clones.

The memory cells of two antibody-forming cell clones had receptors of the IgM class, even though the clones had been producing IgG1 or IgG2a anti-2,4-dinitrophenyl antibodies for 9-15 months previously (on exposure to antigen). Thus a phenotypic switch in heavy chain constant region evidently occurred after re-exposure of these memory cells to antigen. To show that, we first removed the clonal cells' surface immunoglobins by "capping" and "stripping", with class- or subclass-specific antisera. Then, to assay their remaining receptor activity, the cells were incubated with antigen in vitro, washed and transferred (together with carrier primed cells) to irradiated recipients, and their antibody responses to this in vitro boost were assayed by iselectric focusing. Pretreatment with anti-mu serum, as well as with anti-Fab(kappa), prevented the responses of the IgG1 and IgG2a clones to an in vitro boost, while anti-gamma1 and anti-gamma2a antisera had no effect. An antiserum to the putative mouse IgD also had no effect. The anti-mu serum failed to react with the IgG1 and IgG2A clonal serum antibodies in the test tube. Some other contaminating clones were suppressed completely only by the anti-Fab serum. This result strongly suggests that switching in class commitment may occur during the differentiation of memory cells to antibody producers, and may therefore be antigen-dependent. It also implies that some apparently naive cells with surface IgM may, in reality, be B memory cells.

Animals↗
PubMed2003

Rapid urinary antigen test for diagnosis of pneumococcal community-acquired pneumonia in adults.

Streptococcus pneumoniae is suspected to cause an important proportion of community-acquired pneumonia (CAP) whose aetiology cannot be detected with conventional tests. In this study, the authors evaluated the diagnostic yield of a new immunochromatographic membrane test (ICT) for the detection of the S. pneumoniae antigen in the urine of patients admitted with diagnosed CAP. ICT was performed in unconcentrated and concentrated urine from all the patients. ICT was repeated 1 month after discharge in a group initially testing positive. The authors also studied the ICT in clinically stable human immunodeficiency virus type 1 (HIV1)-infected patients. S. pneumoniae antigen was detected in all of the 68 (100%) patients tested with definitive pneumococcal pneumonia. In five of these cases ICT was only positive when it had been performed on the patients. The S. pneumoniae antigen was also detected in 36 (69.2%) of 52 patients with probable pneumococcal pneumonia and in 50 of 277 (18%) patients without pneumococcal pneumonia. ICT remained positive in 16 (69.5%) of 23 patients, 1 month after hospital discharge. Nasopharyngeal colonisation with S. pneumoniae was detected in 8 (12%) of 68 clinically stable HIV1 infected patients, but none tested ICT positive. The Binax NOW it immunochromatographic membrane test is a rapid, sensitive and specific test for detecting pneumococcal community-acquired pneumonia in adults. The test may remain positive for several weeks after pneumococcal pneumonia.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Fc alpha receptor cross-linking causes translocation of phosphatidylinositol-dependent protein kinase 1 and protein kinase B alpha to MHC class II peptide-loading-like compartments.

A20 IIA1.6 B cells cotransfected with FcalphaR and wild-type gamma-chain (wt-ITAM (immunoreceptor tyrosine-based activation motif)) or FcalphaR and gamma-chain, in which the wt-ITAM was substituted with the FcgammaRIIA ITAM (IIA-ITAM), were used to investigate cell signaling events influencing presentation of FcalphaR-targeted exogenous Ag in the context of MHC class II. wt-ITAM cells presented FcalphaR-targeted OVA more efficiently than IIA-ITAM transfectants to OVA-specific T cell hybridomas. Phosphatidylinositol 3-kinase (PI 3-kinase) inhibition abrogated Ag presentation, suggesting that FcalphaR may trigger a PI 3-kinase-dependent signal transduction pathway, and thus phosphatidylinositol-dependent protein kinase (PDK1) and protein kinase B alpha (PKBalpha) activation. Cross-linking FcalphaR on wt-ITAM or IIA-ITAM cells triggered equivalent PI 3-kinase-dependent activation of PKBalpha. Furthermore, FcalphaR cross-linking triggered recruitment of PDK1 and serine-phosphorylated PKBalpha to capped cell surface FcalphaR irrespective of the gamma-chain ITAM. Although FcalphaR endocytosis was accompanied by translocation of PDK1 and phospho-PKBalpha to FcalphaR-containing vesicles in both transfectants, this was decreased in IIA-ITAM cells, and a significant proportion of PDK1 and PKBalpha remained at the plasma membrane. In wt-ITAM cells, PDK1 and serine-phosphorylated PKBalpha translocated to lysosomal-associated membrane glycoprotein 1- and cathepsin B-containing vesicles, consistent with MHC class II peptide-loading compartments (MIIC) described by other groups. Our data indicate that translocation of signal transduction mediators to MIIC-like compartments accompanies efficient presentation of receptor-targeted Ag, and suggest a mechanism connecting signaling to the Ag-processing pathway.

3-Phosphoinositide-Dependent Protein Kinases↗
PubMed2003

Promoter polymorphism in the endotoxin receptor (CD14) is associated with increased carotid atherosclerosis only in smokers: the Carotid Atherosclerosis Progression Study (CAPS).

BACKGROUND AND PURPOSE: The risk of atherosclerosis from endotoxemia is increased in smokers. Endotoxin is a potent mediator of inflammation, and smokers have elevated plasma levels of endotoxin. The endotoxin receptor CD14 can enhance the endotoxin-neutralization capacity of plasma. A functional polymorphism in the promoter region of the CD14 gene (CD14 -159C/T) was studied to determine its impact on common carotid artery (CCA) intima-media thickness (IMT) and any interactions with environmental inflammatory stimuli. METHODS: A community population (n=992; aged 50 to 65 years) underwent genotypic examination for the CD14 -159 polymorphism by restriction fragment length polymorphism analysis. RESULTS: The CC genotype was associated with increased CCA IMT. The age- and sex-adjusted odds ratio for IMT above the 75th percentile was 1.63 (95% CI, 1.19 to 2.24; P=0.002) and 1.70 (95% CI, 1.18 to 2.44; P=0.004) after additional adjustment for conventional risk factors. This gene effect was found only in current smokers and ex-smokers. Multivariate analysis in this group (n=503) increased the odds ratio to 2.02 (95% CI, 1.23 to 3.34; P=0.006). No significant interactions were found in nonsmokers or with alcohol consumption. CONCLUSIONS: The CD14 -159 polymorphism is associated with increased CCA IMT in smokers from a general population. CD14 may modulate the inflammatory effects of smoking in atherogenesis.

Aged↗
PubMed1997

Multicenter evaluation of the flow cytometry T-cell crossmatch: results from the American Society of Histocompatibility and Immunogenetics-College of American Pathologists proficiency testing program.

BACKGROUND: The performance characteristics and interlaboratory comparisons of the T-cell flow cytometry crossmatch remain largely unknown. METHODS: This study was performed using data from the ASHI-CAP proficiency testing program. Four unknown sera and two unknown cells were sent to participating laboratories twice a year for 4 years. RESULTS: In one survey in which different crossmatch techniques were compared, flow cytometry was slightly more sensitive than the antiglobulin method and considerably more sensitive than direct cytotoxicity. However, the proportion of participants in any given survey detecting antibodies in all sera expected to be positive was 50-60% and has not changed over the years. Failure to detect antibodies correlated with low antibody concentration, diluting the unknown serum by the testing laboratory, and with the instrument used. False positive results with normal sera were infrequent. Fluorescence intensity values were not standardized and were highly variable, but when fluorescence units reported by individual laboratories were divided by their own positive-negative cutoff values, results from different centers were more comparable. In general, fluorescence-to-cutoff ratios >5 correlated with complement binding activity, whereas values <5 denoted concentrations below those required to fix complement. CONCLUSIONS: Flow cytometry, as used by most centers, is highly sensitive and allows relative antibody quantitation. Furthermore, the data define objective parameters that may help to standardize the test and improve its predictive value in clinical transplantation.

Antibodies↗
PubMed2006

IgE reactivity to latex allergens among sensitized healthcare workers before and after immunotherapy with latex.

BACKGROUND: New IgE sensitizations to proteins in allergen extracts have been shown to occur during allergen-specific immunotherapy (IT). METHODS: Twenty-four healthcare workers (HCWs) -- patients included in a latex IT study -- were analysed, 16 in active treatment and eight in placebo. Sera were obtained at baseline and after 6 months of IT and analysed with immunoblotting and CAP System with eight single recombinant latex allergens (rHev b 1, 3, 5, 6.01, 8, 9, 10, 11, and a mix of rHev b1, 5, 6.01 and 8). RESULTS: After IT with latex, three patients in the active treatment group had new IgE sensitizations, one to Hev b 5, one to Hev b 11 and another to Hev b 6.01. No other significant variation in mean of specific IgE to latex or recombinant allergens were observed in patients who received placebo or active treatment. A significant (P = 0.012) negative correlation (-0.72) was observed between maximal tolerated dose and specific IgE to Hev b 6.01 at baseline. After IT, immunoblot analysis demonstrated a significant increase in IgE binding in a band of approximately 22 kDa (P = 0.032) that may correspond to Hev b 6.01. New or more intense bands appeared in seven patients of the active group, while in three subjects a reduction was observed. CONCLUSIONS: Hev b 6.01 seems to be the most relevant latex allergen in HCWs. New or more intense IgE binding to latex allergenic components occurs during latex immunotherapy. However, the levels of specific IgE against these new components are low and do not seem to have clinical relevance.

Allergens↗
PubMed2000

Specific cytolytic T-cell responses to human CEA from patients immunized with recombinant avipox-CEA vaccine.

Avipox viruses are replication-defective members of the poxvirus family. Avipox-derived vectors such as ALVAC (canarypox) and fowlpox have the ability to infect mammalian cells, including human cells, but do not replicate. The first clinical trial of an avipox recombinant vaccine for patients with advanced carcinomas has recently been conducted using the ALVAC vector and the human carcinoembryonic antigen (CEA) transgene (designated ALVAC-CEA; J. L. Marshall et al, J. Clin. Oncol., 17: 332-337, 1999). The T-cell responses elicited by patients before and after vaccination with the ALVAC-CEA recombinants are characterized in this report. Pre- and postvaccination peripheral blood mononuclear cells (PMBCs) of the eight patients positive for HLA-class I A2 allele, were incubated with the HLA-A2-CEA peptide CAP-1 and interleukin 2. In no cases using prevaccination PMBCs could cultures be established that had the ability to lyse C1R-A2 target cells pulsed with the CAP-1 peptide. However, T-cell cultures from seven of eight of these same patients, obtained from PBMCs after ALVAC-CEA vaccination, were shown to lyse C1R-A2 cells only when pulsed with CAP-1. Moreover, all seven of these T-cell cultures were shown to lyse allogeneic human carcinoma cell lines (SW1463 and SW480) that were both A2+ and expressed CEA; an allogeneic tumor cell line (LS174T) expressing CEA that was negative for A2 expression was not lysed. HLA-A2+ and CEA+ autologous tumor cells were also capable of being lysed by CEA-specific T cells from this patient. Analysis of this CTL line also revealed the expression of several homing and adhesion-associated molecules. Fluorescence-activated cell sorter analysis of the T-cell lines established from patients after ALVAC-CEA vaccination revealed that most were CD8+/CD4-, but many also had a CD8+/CD4+ component. Analyses of T-cell receptor Vbeta usage of several of the CEA-specific CTL lines showed a relatively diverse Vbeta pattern. These studies demonstrate for the first time the ability to vaccinate cancer patients with an avipox recombinant and derive T cells that are capable of lysing allogeneic and autologous tumor cells in a MHC-restricted manner. These studies thus form the rationale to use such replication-deficient recombinant vaccines in future cancer vaccine trials.

Antigen-Presenting Cells↗
PubMed1995

Characterization of the cytolytic trigger molecules G7/PNK-E as a molecular complex on the surface of porcine phagocytes.

G7 and PNK-E mAbs recognize distinct porcine NK cell and granulocyte function-associated molecules that enhance and induce a significant cytolytic response against tumor cell targets through a mechanism of re-directed cytotoxicity. The present study shows that the G7 and PNK-E molecules are present on the surface of porcine neutrophils, monocytes, and pulmonary alveolar macrophages as a physically and functionally associated cytolytic trigger molecular complex. Two-color flow cytometric analysis demonstrates that most, if not all, neutrophils are G7 and PNK-E antigen positive. In contrast, monocytes and PAM contain both G7 and PNK-E positive as well as G7 positive and PNK-E negative subpopulations. mAb binding competition experiments indicate that pretreatment of phagocytes with G7 mAb can block subsequent binding by PNK-E mAb, suggesting that these antigens are physically associated on the surface of porcine phagocytes. Fluorescent co-capping experiments utilizing G7 and PNK-E mAbs clearly demonstrate a physical association between G7 and PNK-E antigens present on the surface of porcine neutrophils. Pretreatment of phagocytes with F(ab')2 fragments of G7 and PNK-E mAbs shows that F(ab')2 G7 mAb blocks subsequent induction of phagocyte-mediated tumor cell cytotoxicity by whole PNK-E mAb but pretreatment with F(ab')2 PNK-E does not block subsequent induction of phagocyte-mediated tumor cell cytotoxicity by whole G7 mAb. In addition, pretreatment of neutrophils and mononuclear phagocytes with F(ab')2 fragments of G7 mAb blocks subsequent whole PNK-E mAb-dependent activation of a phagocytic cell intracellular oxidative burst response but pretreatment with F(ab')2 PNK-E does not block subsequent G7 mAb-dependent activation of a phagocytic cell intracellular oxidative burst response. These data reinforce a physical and functional association between the G7 and PNK-E molecules. Recent identification of the G7 antigen as the porcine homolog of Fc gamma RIII indicates that the G7 and PNK-E mAbs recognize a unique and previously uncharacterized Fc gamma R cytolytic trigger molecular complex present on the surface of porcine neutrophils, monocytes, and PAM.

Animals↗
PubMed2006

Usefulness of specific immunotherapy in patients with atopic dermatitis and allergic sensitization to house dust mites: a multi-centre, randomized, dose-response study.

BACKGROUND: The effect of specific immunotherapy (SIT) on eczema in atopic dermatitis is not known. Therefore, a multi-centre, randomized dose-response trial, double-blind with respect to the efficacy of a biologically standardized depot house dust mite preparation was performed. METHODS: Eighty-nine adults with a chronic course of atopic dermatitis, SCORAD >or=40 and allergic sensitization to house dust mites [CAP-FEIA >or=3] were included, of whom 51 completed the study. Subcutaneous SIT with a house dust mite preparation (Dermatophagoides pteronyssinus/D. farinae) applying maintenance doses of 20, 2,000 and 20,000 SQ-U in weekly intervals for 1 year. The main outcome measures addressed the change of the SCORAD as average of the values after 9 and 12 months of SIT in comparison with the value at baseline. RESULTS: The SCORAD declined in the three dose groups in a dose-dependent manner (P = 0.0368, Jonckheere-Terpstra test) and was significantly lower in the two high-dose groups (2,000, 20,000 SQ-U) compared with the low-dose group of 20 SQ-U (P = 0.0379, U-test) after 1 year of SIT. The use of topical corticosteroids was significantly reduced with higher doses (P = 0.0007, Mantel-Haenszel chi-square test). CONCLUSIONS: Allergen-SIT for 1 year with a house dust mite preparation is able to improve the eczema in patients with atopic dermatitis who are sensitized to house dust mite allergens and reduces the need for topical corticosteroids. SIT may be valuable in the treatment of this chronic skin disease.

Adolescent↗
PubMed2005

Contraceptive responses of female hamsters immunized with recombinant sperm protein P26h.

BACKGROUND: A number of antigens have been characterized and proposed as potential candidates for immunocontraception. P26h, a 26-kDa hamster sperm protein located on the acrosomal cap, is known to be involved in sperm-zona pellucida interactions. Furthermore, in vivo fertilization can be blocked by active immunization of male hamsters against P26h or maltose-binding protein recombinant P26h (MBP-P26h). OBJECTIVE: The aim of this study was to investigate the immune response and reproductive function of female hamsters immunized against MBP-P26h. RESULTS: Active immunization against MBP-P26h resulted in anti-P26h circulating antibodies, with enzyme-linked immunosorbent assay (ELISA) titers showing interindividual variability. The antibodies produced by the animals immunized against MBP-P26h reacted with the native P26h protein in ELISA, in Western blot analysis and in immunostaining performed on cauda epididymal spermatozoa. Mating of immunized female hamsters resulted in a significant decrease in the number of viable fetuses only in females with high titers of anti-P26h circulating antibodies. DISCUSSION: This result is in agreement with the sperm-zona pellucida binding assay's results. Indeed, sera collected from immunized animals, and not from control animals, significantly blocked sperm-zona pellucida binding in vitro. Histological studies showed that active immunization did not cause any pathology in the reproductive tissues. CONCLUSION: These findings suggest that P26h is a potential candidate for the development of a contraceptive vaccine in both males and females.

Alcohol Oxidoreductases↗
PubMed2004

Effect of prolactin on carcinoembryonic antigen-specific cytotoxic T lymphocyte response induced by dendritic cells.

The cytokine hormone prolactin (PRL) has been shown previously to modulate native cellular responses and maturation of antigen-presenting cells. Here we have addressed its effect on the antigen-specific response of cytotoxic T lymphocytes (CTL). CTL were generated from HLA-A2 lymphocytes after three rounds of stimulation with autologous dendritic cells loaded with HLA-A2-restricted carcinoembrionic antigen (CEA) Cap-1 (YLSGANLNL) peptide. Selected cultures were expanded on cytokine-supplemented feeder-layers, enriched for CD8+ lymphocytes and analysed for PRL-receptor (PRL-R) expression and PRL responsiveness. Resting CD8+ lymphocytes were negative for PRL-R, whereas antigen-activated CD8+ lymphocytes derived from long-term cultures were highly positive. Results of a 51Cr release assay showed CTL killing of CEA-loaded, but not unloaded, T2 cell line and the CEA-positive gastric carcinoma cell line KATO, but not of the CEA-negative T leukaemia cell line Jurkat. Interferon (IFN)-gamma release, evaluated in an ELISPOT assay against CEA-loaded T2, was enhanced (P < 0.05) by concentrations of PRL (12-25 ng/ml) very close to the physiological levels (6-20 ng/ml), but was decreased (P < 0.05) by high concentrations (200 ng/ml). Pre-incubation of the stimulators with the anti-MHC class I MoAb W6.32 induced a 40-60% decrease of the PRL-boosted IFN-gamma release, thus proving the MHC restriction of the lymphocyte response. Cytotoxicity against CEA-loaded T2 and KATO cell lines was also increased by 12-25 ng (P < 0.05) and decreased (P < 0.05) by 200 ng PRL. Pre-incubation of CTL with an antibody specific for the PRL-R almost completely abrogated this effect.

Carcinoembryonic Antigen↗
PubMed1994

Progress report on the ASHI/CAP Proficiency Survey Program in Histocompatibility Testing. I. HLA-A,B,C typing, antibody screening, and lymphocytotoxicity crossmatching. American Society for Histocompatibility and Immunogenetics. College of American Pathologists.

The Histocompatibility Survey Program was organized in 1982 as a joint project by the ASHI and CAP to evaluate laboratory performance in HLA typing, lymphocytotoxicity crossmatching, and antibody analysis. This report summarizes the experience with the HS surveys on HLA class I serology. During a 12-year period, the number of participating laboratories increased from 150 to 285 and HLA typing was done with 90 survey specimens representing 20 HLA-A and 35 HLA-B antigens. Most unsplit antigens were correctly identified in more than 90% of the laboratories. For many antigens, a high percentage of participants reported a split and there was generally a high consensus of a correct assignment. Nevertheless, several antigens were difficult to define, as shown by low consensus rates. During recent years, the assignments of Bw4/6 and HLA-C antigens have significantly improved. Lymphocytotoxicity crossmatching was analyzed for 138 cell-serum combinations tested by an average of 143 laboratories. Comparisons between four techniques (basic NIH, Amos modified, LI, and AHG) showed consistent results (greater than 90% crossmatch compatibility or incompatibility) for 71% of the cell-serum combinations. The crossmatch results with the remaining combinations were more variable for one or more of the crossmatch techniques. Serum antibody identification showed a continued improvement during recent years, and the average consensus for assigning acceptable antibody specificity reached 88%. A performance grading system based on a 90% consensus rate among participants is used to satisfy requirements for laboratory accreditation.

Cytotoxicity Tests, Immunologic↗