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1.
J Mycol Med ; 29(1): 49-55, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30470620

ABSTRACT

OBJECTIVE: The effect of candidemia on immunologic parameters in breast tumor bearing patients is not well studied. Here, we hypothesised that candidemia in the tumor background may change the outcome of immunologic parameters and tumor condition. METHOD: Mice were divided into four groups, including normal, tumor, Candida infected (only Candidiasis) and tumor/Candidiasis groups. Tumor changes were recorded daily after tumor transplantation and induction of candidemia. Splenocytes of mice were harvested, cultured, and stimulated with PHA; afterwards, IL-4, IL-10, IFN-γ, TNF-α and TGF-ß cytokines were assessed using ELISA kits. We also evaluated the population of CD4+CD25+Foxp3+ regulatory T cells in the tumor infiltrated and splenocytes. RESULTS: The results showed that infection with C. albicans decreased the IFN-γ/IL-4 ratio in tumor/candidiasis and candidiasis groups versus their non-infected controls. IL-10, TGF-ß and TNF-α levels increased in the candidiasis group. In addition, Candidemia led to an increase in the Treg population in tumor microenvironment and splenocytes of experimental groups compared with non-infected controls. Finally, candidemia increased tumor growth of tumor/Candidiasis group compared with the tumor group. CONCLUSION: It seems that systemic infection with C. albicans could not only induce regulatory T cells but also result in dysregulation of cytokine network and thereby facilitate tumor growth.


Subject(s)
Breast Neoplasms/immunology , Candidemia/immunology , Cytokines/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Breast Neoplasms/physiopathology , Candida albicans , Female , Interferon-gamma/immunology , Interleukin-10/immunology , Interleukin-4/immunology , Mice , Mice, Inbred BALB C , Spleen/cytology , Spleen/drug effects , Transforming Growth Factor beta1/immunology , Tumor Necrosis Factor-alpha/immunology
2.
J Phys Condens Matter ; 23(24): 245602, 2011 Jun 22.
Article in English | MEDLINE | ID: mdl-21628789

ABSTRACT

We investigate single-particle spectral densities and dynamical charge and spin structure factors of the one-dimensional extended ionic Hubbard model in the band insulator regime by using the perturbative continuous unitary transformations method. The one-body staggered potential is considered as the unperturbed part and the hopping term, on-site electron-electron interaction, and the nearest-neighbor repulsive interaction are treated as the perturbations. The excitation spectrum of this model was determined in a previous work (Hafez and Jafari 2010 Eur. Phys. J. B 78 323). It was shown that when the intersite interaction is off, there are two antibound state modes and one bound state mode in the singlet channel and two bound state modes in the triplet channel, while for finite values of intersite interaction two bound state modes were found in each channel. Our results for dynamical charge and spin structure factors indicate that only one of two bound/antibound state modes can be probed by electron-energy-loss spectroscopy and inelastic neutron scattering experiments.


Subject(s)
Ions/chemistry , Models, Chemical , Computer Simulation , Electron Transport
3.
Int J Pharm ; 409(1-2): 307-13, 2011 May 16.
Article in English | MEDLINE | ID: mdl-21356293

ABSTRACT

Gene delivery using cationic polymers such as chitosan shows good biocompatibility, but reveals low transfection efficiency. Fibronectin Attachment Protein of Mycobacterium bovis (FAP-B) which is responsible for the attachment of many Mycobacteria on the Fibronectin molecule of epithelial cell membrane can be considered as a new targeting ligand and can improve transfection rates in epithelial cells. In this study, chitosan-DNA nanoparticles were prepared using coacervation process. The effect of stirring speed and charge ratio (N/P) on the size and zeta potential of nanoparticles were evaluated. FAP-B ligand was added to nanoparticles at the specific condition to form chitosan-DNA-FAP-B nanoparticles via electrostatic attraction. Transfection efficiency of the final nanoparticles was investigated in A549 (alveolar epithelial cells). Cell viability was investigated using MTT assay. The optimum speed of stirring which was yielded the smallest chitosan-DNA nanoparticles with a narrow distribution (227±43 nm), was 500 rpm with the corresponding N/P ratio of 20. Chitosan-DNA-FAP-B nanoparticles presented the size of 279±27 nm with transfection efficiency about 10-fold higher than chitosan-DNA nanoparticles and resulted in 97.3% cell viability compared to 71.7% using Turbofect controls. Chitosan-DNA-FAP-B nanoparticles showed good transfection efficiency without cell toxicity. They have small particle size around 279 nm which make them a promising candidate as a novel non-viral gene vector for gene delivery to lung epithelial cells.


Subject(s)
Adhesins, Bacterial/chemistry , Chitosan/chemistry , DNA/administration & dosage , Gene Transfer Techniques , Cell Line , Cell Survival/drug effects , Epithelial Cells/metabolism , Gene Targeting , Genetic Therapy/methods , Genetic Vectors/chemistry , Humans , Lung/metabolism , Nanoparticles , Particle Size , Transfection/methods
4.
Asian Pac J Trop Biomed ; 1(1): 54-6, 2011 Jan.
Article in English | MEDLINE | ID: mdl-23569725

ABSTRACT

OBJECTIVE: To carry out an experimental study with the main objective of mass rearing of sheep flies (Lucilia sericata). METHODS: Hand collection and beef- or cattle liver-baited net traps were used for field fly sampling from April, 2010 to November, 2010. The samples collected from different places were placed in properly labeled tubes and sent to the Entomology Laboratory. Since maggot identification is important in inducing mortality, they were kept under insectary condition to develop to adult stage and identified using systematic keys. RESULTS: A total of 218 flies were collected in three rounds of sampling from the field of Tehran and Karaj Counties. In the first generation, 433 flies including 135 (31.17%) male, and 298 (68.82%) female were yielded. The female/male of parent ratio was calculated as 1.72 in Tehran and in Karaj areas, whereas it was 2.20% and 1.81%, respectively in F1 and F2 generations, respectively. CONCLUSIONS: During this study, the mass rearing of sheep blow fly has been established at the School of Public Health, Tehran University of Medical Sciences and can be used for producing flies for maggot therapy.


Subject(s)
Diptera , In Vitro Techniques/methods , Larva , Animals , Female , Iran , Male , Therapeutics/methods
5.
Acta Virol ; 54(2): 131-6, 2010.
Article in English | MEDLINE | ID: mdl-20545443

ABSTRACT

UNLABELLED: Many Human immunodeficiency virus (HIV) candidate vaccines have been tested in clinical trials, but none was sufficiently effective in the prevention of HIV infection. A HIV vaccine should induce humoral as well as cell-mediated response, the latter including the cytotoxic CD8+ T lymphocyte (CTL) response. In this study, we immunized BALB/c mice with a purified fusion peptide Gag p24-Nef and evaluated immune responses. As for the cellular responses, the adjuvanted fusion peptide induced lymphocyte proliferation, CTL response, and cytokines IFN-gamma and IL-4 in the Th1 pattern. Humoral immune response to the adjuvanted fusion peptide included an increase in IgG antibodies of more IgG2a than IgG1 subtype. These results indicate that the employed HIV-1 peptide construct can elicit both cellular and humoral immune responses in mice. Further studies aimed at memory T cells and other aspects of immune responses are needed before a comprehensive assessment of this candidate vaccine could be provided. KEYWORDS: epitopes; fusion peptide; HIV-1 p24-Nef; immune response.


Subject(s)
AIDS Vaccines/immunology , HIV Core Protein p24/immunology , HIV-1/immunology , nef Gene Products, Human Immunodeficiency Virus/immunology , AIDS Vaccines/pharmacology , Animals , Female , HIV Antibodies/biosynthesis , Humans , Immunity, Cellular , Immunity, Humoral , Immunoglobulin G/biosynthesis , Interferon-gamma/biosynthesis , Interleukin-4/biosynthesis , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Models, Animal , Recombinant Fusion Proteins/immunology , T-Lymphocytes, Cytotoxic/immunology
6.
8.
J Chromatogr A ; 1216(48): 8563-6, 2009 Nov 27.
Article in English | MEDLINE | ID: mdl-19857867

ABSTRACT

Columns of phosphorylcholine (PC) immobilized on silica gel were shown to be useful for size exclusion chromatography (SEC) of proteins. The columns provided good separation of proteins in 50mM sodium phosphate buffer (pH 6.9) containing 0.25 M NaCl, and there was a linear relationship between the retention times and the logarithmic values of the molecular weights with a correlation coefficient (R(2)) of 0.978-0.992. The columns were used in analyzing the subunit structures of the rhamnose-binding lectins CSL1, CSL2, and CSL3, isolated from chum salmon (Oncorhynchus keta) eggs. Although the lectins, which are a group of carbohydrate-binding and hydrophobic proteins, behaved anomalously in SEC with conventional matrices, they could be eluted from the immobilized PC columns without non-size-related retention, thereby allowing their molecular weights to be reliably estimated.


Subject(s)
Chromatography, Gel/methods , Fishes , Lectins/chemistry , Ovum/chemistry , Phosphorylcholine/chemistry , Protein Subunits/analysis , Silicon Dioxide/chemistry , Animals , Chromatography, Gel/instrumentation , Hydrogen-Ion Concentration , Lectins/analysis , Molecular Weight , Protein Subunits/chemistry , Silica Gel , Time Factors
9.
Inflamm Res ; 57(9): 419-29, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18777115

ABSTRACT

OBJECTIVE AND DESIGN: We evaluated the role of the osmolarity in the pro-inflammatory responses of epithelial cells. MATERIAL: Twenty-five female Wistar rats and colorectal (HT-29) and bladder (T24) cell lines were used. TREATMENTS: Rats and cells were exposed for 48 hours to hyperosmotic solutions. METHODS: Interleukin-8 (IL-8) production was measured by Enzyme Linked ImmunoSorbent Assay, mRNA transcription of pro-inflammatory cytokines by microarrays or RNase Protection Assay. Nuclear factor-kappa B (NF-kappaB) pathway and Protein Phosphatase 2A (PP2A) activations were measured. Myeloperoxydase (MPO) activation and Macrophage-Inflammatory Protein-2 (MIP-2) transcription were monitored. RESULTS: The exposure to hyperosmotic solutions enhanced the production of IL-8 and induced pro-inflammatory cytokines transcription. In vivo, MPO enhanced activity accompanied by an increased MIP-2 transcription was observed. In vitro, NF-kappaB activation is accompanied by an inhibitor of kappa B-alpha degradation and inhibitor of kappa B kinase (IKK gamma) activation. We demonstrated the induction of IKK gamma after methylation and activation of PP2A. Cytokine induction was inhibited by okadaic acid and calyculin A and stimulated by xylitol. CONCLUSION: Hyperosmolarity can induce pro-inflammatory cytokine responses in colorectal and bladder epithelial cells. Inflammation appears to be the simple consequence of a shift of methylation of PP2A which in turn activates NF-kappaB.


Subject(s)
Inflammation/etiology , Protein Phosphatase 2/metabolism , Animals , Cell Line, Tumor , Chemokines/biosynthesis , Cytokines/biosynthesis , Epithelial Cells/immunology , Female , Humans , I-kappa B Kinase/metabolism , Methylation , NF-kappa B/metabolism , Osmolar Concentration , Peroxidase/metabolism , RNA, Messenger/analysis , Rats , Rats, Wistar
10.
Scand J Clin Lab Invest ; 66(3): 201-9, 2006.
Article in English | MEDLINE | ID: mdl-16714249

ABSTRACT

OBJECTIVE: Malaria has been prevalent for a long time in Iran and continues to be a health problem despite substantial control programs. In addition to numerous cytokines, nitric oxide (NO) is thought to be a key molecule and a novel target of malaria immunopathology. MATERIAL AND METHODS: The objective of this research was to measure reactive nitrogen intermediates (RNI) as stable metabolites of NO induction in plasma of malaria-infected patients in Iran. In this study, 235 blood samples from malaria patients and 80 blood samples from healthy controls were randomly collected from different malarial endemic provinces of Iran, located in southeastern (Sistan & Balouchestan, Hormozgan, Kerman) and northwestern (Ardabil) areas. The involvement of NO in malaria patients has been investigated by statistical analysis of RNI values. Griess micro assay (GMA) was used during Plasmodium vivax, P. falciparum and mixed infections, in order to evaluate whether RNI changes are related to the provincial areas, parasite strains, clinical symptoms and age and gender parameters. RESULTS: The results showed a significant increase of RNI level in malaria patients compared with the control groups of Ardabil (p<0.01), Sistan & Balouchestan, Hormozgan and Kerman (p<0.001) provinces. The level of RNI was higher in mixed plasmodial infection than in single infection. CONCLUSIONS: The high level of RNI was dependent on the type of infection, the plasmodia strain, the clinical symptoms, the age groups and the endemic provinces. Although, this study did not clarify the pathogenic and/or protective role of NO in malaria, our findings provide a novel immunoepidemiological aspect of basal NO production in patients with malaria in endemic areas in Iran.


Subject(s)
Malaria/blood , Nitric Oxide/biosynthesis , Adolescent , Adult , Case-Control Studies , Child , Child, Preschool , Female , Humans , Infant , Iran/epidemiology , Malaria/epidemiology , Malaria/immunology , Malaria, Falciparum/blood , Malaria, Falciparum/epidemiology , Malaria, Falciparum/immunology , Malaria, Vivax/blood , Malaria, Vivax/epidemiology , Malaria, Vivax/immunology , Male , Middle Aged , Nitric Oxide/blood , Reactive Nitrogen Species/blood
11.
Conf Proc IEEE Eng Med Biol Soc ; 2006: 1731-4, 2006.
Article in English | MEDLINE | ID: mdl-17946477

ABSTRACT

The auditory periphery system receives a one dimensional acoustical signal that describes how the local pressure varies with time. However, this one dimensional signal information is then somehow unfolded into a two dimensional time-frequency plane, that tells us when which frequency occurs. The hearing process is based on compromise between time localization and frequency localization. A kind of time-frequency or wavelet type transformation is done in auditory signal processing. In this study the similarities between auditory transform based on the auditory physiological process and wavelet transform are introduced. Specially, band pass filter bank properties and variable time and frequency resolutions with the signal frequency are considered. The main goal is to find the scaling function while the numerical values of the wavelet function were measured. If the wavelet function and the scaling function from the measured data are estimated, then the wavelet coefficients and the scaling coefficients could be calculated. Therefore, the multiresolution implementation of auditory based wavelet transform is possible.


Subject(s)
Algorithms , Cochlea/physiology , Models, Biological , Pitch Perception/physiology , Signal Processing, Computer-Assisted , Humans
12.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 1567-70, 2005.
Article in English | MEDLINE | ID: mdl-17282503

ABSTRACT

We proposed an efficient method for classification of diffused liver diseases based on Gabor wavelet. It is well known that Gabor wavelets attain maximum joint space-frequency resolution which is highly significant in the process of texture extraction and presentation. This property has been explored here as the proposed method outperforms the classification rate obtained by using dyadic wavelets and methods based on statistical properties of textures. The feature vector is relatively small compared to other methods. This has a significant impact on the speed of retrieval process. In addition, the proposed algorithm is not sensitive to shift of the image contents. Since shifting the contents of an image will cause a circular shift of the Gabor filter coefficients in each sub-band. The proposed algorithm applied to discriminate ultrasonic liver images into three disease states that are normal liver, liver hepatitis and cirrhosis. In our experiment 45 liver sample images from each three disease states which already proven by needle biopsy were used. We achieved the sensitivity 85% in the distinction between normal and hepatitis liver images and 86% in the distinction between normal and cirrhosis liver images. Based on our experiments, the Gabor wavelet is more appropriate than dyadic wavelets and statistical based methods for texture classification as it leads to higher classification accuracy.

13.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 2773-6, 2005.
Article in English | MEDLINE | ID: mdl-17282816

ABSTRACT

To improve transient evoked otoacoustic emission (TEOAE) test accuracy, a new technique in presented based on multiresolution signal decomposition. Using a wavelet function which optimized according to an active cochlear model, time frequency distribution of TEOAE is obtained. The coefficients of the filter bank are determined from Morlet mother wavelet function in the analysis section. In the synthesis section, time windows are obtained from deduced latency curve. By applying this multiresolution analysis, the correlative noise would be canceled. Therefore, the wave reproducibility can be increased without loss of measuring reliability. In abnormal cases where response is not expected the correlative noise is considered as response are completely disappeared. Thus this will increase the accuracy of screening results.

14.
Scand J Immunol ; 55(3): 293-303, 2002 Mar.
Article in English | MEDLINE | ID: mdl-11940236

ABSTRACT

Cell-mediated immunity plays a key role in containing the growth of Mycobacterium tuberculosis in the host. The induction of an antibody response or a mixed cell-mediated and humoral response is frequently associated with tuberculosis disease or a decrease in the ability to control M. tuberculosis load. We recently reported the induction of similar immune responses and protection by rectal, subcutaneous (SC) or intradermal administration of Mycobacterium bovis BCG in adult mice, guinea pigs and macaques. The rectal immunization, which did not induce the side-effects associated with parenteral routes (axillary adenitis) and which could be used to reduce the risks of viral transmission associated with unsafe injections in the developing world, was analysed and compared in newborn and adult BALB/c mice. The rectal and SC immunization induced, in mice immunized as newborns or as adults, a mixed T helper 1/T helper 2 (Th1/Th2) immune response; however, particularly in adult mice, after SC administration of BCG, the level of Th2 immune response is significantly higher than it is by the rectal route. Six months after immunization with BCG, rectal and SC delivery induced similar levels of protective immunity against a virulent challenge with M. tuberculosis strain (H37Rv) in mice immunized as adults, but the rectal BCG delivery triggered stronger protection than the SC delivery if mice were immunized as newborns.


Subject(s)
BCG Vaccine/administration & dosage , Mycobacterium tuberculosis/immunology , Th1 Cells/immunology , Th2 Cells/immunology , Administration, Rectal , Animals , Animals, Newborn , Colony Count, Microbial , Female , Injections, Subcutaneous , Interferon-gamma/biosynthesis , Mice , Mice, Inbred BALB C , Mycobacterium bovis/isolation & purification
15.
Braz J Infect Dis ; 5(6): 345-51, 2001 Dec.
Article in English | MEDLINE | ID: mdl-12010599

ABSTRACT

In this report we have analysed the peripheral blood lymphocyte of several patients with chronic hepatitis B virus infection with flow cytometry. Based on the presence and absence of the HBeAb, patients were divided into two groups. In both, all the patients were HBsAg positive with normal range of serum alanine aminotranferase (23.9 +/- 17.8). We have found that the immunophenotypic profiles of patients were different from healthy donors with significant decrease in CD(3)(+) T cells, specially CD(8)(+) T cells and a significant increase in the CD(19)(+) B cells. The differences were seen in other subset of T cells (CD(4)(+)) or NK cells (CD(56)(+)/CD(16)(+)) and HLA-DR markers were not significant. When the phenotypic profiles of both groups were compared with each other, such changes were more dominant in group II, with HBeAb positive than in group I, with HBeAb negative. Also, we have seen a correlation between the increase of CD(19)(+) B cells and the decrease of CD CD(3)(+) T cells. No such correlation was observed with other cells.


Subject(s)
Hepatitis B virus/immunology , Hepatitis B, Chronic/immunology , Immunophenotyping , Lymphocyte Subsets , Adult , Aged , Aged, 80 and over , Female , Flow Cytometry , Hepatitis B Antibodies/blood , Hepatitis B Surface Antigens/blood , Hepatitis B e Antigens/immunology , Hepatitis B virus/isolation & purification , Hepatitis B, Chronic/virology , Humans , Male , Middle Aged
16.
Infect Immun ; 68(10): 5657-62, 2000 Oct.
Article in English | MEDLINE | ID: mdl-10992467

ABSTRACT

We compared cellular immune responses to rectal, subcutaneous, and intradermal administration of Mycobacterium bovis BCG for 5 to 20 weeks in mice, guinea pigs, and macaques. Strong lymphoproliferative responses were induced in spleen cells after in vitro stimulation with purified protein derivative in guinea pigs and macaques, whatever the route of immunization. Comparable high numbers of gamma interferon- and tumor necrosis factor alpha-producing cells were found in the spleen after rectal, subcutaneous, and intradermal immunization of mice and macaques. Similar levels of precursors of cytotoxic T lymphocytes specific for mycobacterial antigens were observed in mice for all immunization routes. In macaques, cytotoxic activity, determined only at the end of the experiment (20 weeks), was similar after rectal and intradermal immunization. Six months after immunization, rectal and subcutaneous routes induced in mice similar levels of protective immunity against challenge with a virulent Mycobacterium tuberculosis strain (H37Rv). Rectal immunization gave immune responses and protective capacity similar to those for parenteral immunization and seemed to be a promising new route of vaccination against tuberculosis; in our study, immunization via the rectal route never induced side effects associated with parenteral routes (axillary adenitis) and could also effectively reduce the risks of viral transmission associated with unsafe injections in the developing world.


Subject(s)
BCG Vaccine/administration & dosage , BCG Vaccine/immunology , Mycobacterium bovis/immunology , Tuberculosis/prevention & control , Administration, Rectal , Animals , BCG Vaccine/adverse effects , Cytokines/biosynthesis , Germ-Free Life , Guinea Pigs , Infusions, Parenteral , Lymphocyte Activation , Macaca , Mice , Mice, Inbred BALB C , Spleen/cytology , Spleen/immunology , T-Lymphocytes, Cytotoxic/immunology , Tuberculosis/immunology , Vaccination
17.
J Interferon Cytokine Res ; 15(2): 179-85, 1995 Feb.
Article in English | MEDLINE | ID: mdl-8590322

ABSTRACT

We have identified a new antiproliferative activity from the conditioned medium of two androgen-independent prostatic cancer cell lines, PC3 and DU-145. This antiproliferative activity selectively inhibited cell proliferation of an androgen-dependent prostate cancer cell line LNCaP in a dose-dependent manner. No antiproliferative activity was observed against mouse fibroblast 3T3, normal human lymphocytes, human leukemic cells, including promyelocyte HL-60 or T cell HUT-78, or human adenocarcinoma cell lines, including prostatic cells JCA-1, ovary NIH:OVCAR-3, cervix C-33A, or breast MDA-MB-231. Cell cycle analysis revealed that the antiproliferative activity did not induce apoptosis in LNCaP cells, but it prevented some G1 LNCaP cells from entering into the S phase of the cell cycle. The antiproliferative activity was sensitive to high temperature (100 degrees C) and to proteinase digestion; however, it was resistant to 56 degrees C, pH 2.0, and reducing agent treatment, as well as to DNase and RNase digestion. The antiproliferative activity was partially purified by gel filtration, ion-exchange chromatography, and SDS-PAGE, with an apparent molecular weight of 50 kD. The antiproliferative activity was not affected by neutralizing antibody against TGF-beta 1,2,3, TNF-alpha, PDGF, EGF, IL-1, IL-2, IL-3, IL-4, or IL-6.


Subject(s)
Androgens/metabolism , Carcinoma/metabolism , Prostatic Neoplasms/metabolism , Carcinoma/immunology , Cell Cycle , Cell Division , Culture Media, Conditioned , Cytokines/metabolism , Deoxyribonucleases/pharmacology , Dithiothreitol/pharmacology , Endopeptidases/pharmacology , Female , Humans , Hydrogen-Ion Concentration , Male , Neutralization Tests , Prostatic Neoplasms/immunology , Ribonucleases/pharmacology , Temperature , Tumor Cells, Cultured
18.
Oncol Rep ; 2(5): 811-3, 1995 Sep.
Article in English | MEDLINE | ID: mdl-21597822

ABSTRACT

We have identified an immunosuppressive activity from the conditioned medium of an androgen-independent human prostatic carcinoma cell line, JCA-1. This activity is constitutively produced by JCA-1 cells and is capable of suppressing normal human peripheral blood lymphocyte proliferation irreversibly in a dose-dependent manner. Immunosuppressive activity was semi-purified by a combination of ion-exchange chromatography and gel filtration with an apparent molecular weight of 40-55 kDa. The immunosuppressive activity was not cytolytic to lymphocytes and was sensitive to 56 degrees C, reducing agent as well as to protease digestion. Cell cycle analysis revealed that the suppressive activity did not induce apoptosis, but it prevented some G(1) lymphocytes from entering into the S phase of the cell cycle.

19.
FEMS Immunol Med Microbiol ; 8(2): 151-5, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8173554

ABSTRACT

Modulation of cellular immune responses by the spirochaete Borrelia burgdorferi, the bacteria that causes Lyme disease, was demonstrated. When cultured in the presence of sonicated Borrelia preparation (Bb), the mitogen- or antigen-stimulated proliferative responses of normal lymphocytes were consistently lowered. Bb caused the greatest reduction in Concanavalin A (ConA) or antigen-stimulated proliferation, where almost 100% reduction in proliferation could be achieved. Bb also reduced phytohemagglutinin-M (PHA) or pokeweed mitogen (PWM)-stimulated peripheral blood lymphocyte (PBL) proliferation, with the PWM proliferation being the least affected. This regulatory activity was not due to toxicity and was determined to be caused by Bb protein antigens. The degree of the proliferation reduction was directly proportional to both Bb quantity and length of exposure to lymphocytes. IL-2 production was significantly reduced from Bb-exposed lymphocytes. The entry of lymphocytes into the proliferating phases of the cell cycle was also shown to be blocked. These results have demonstrated an immune suppressive mechanism of B. burgdorferi. The magnitude of host immune responses may be dependent on the degree of suppression which is related to the spirochaete quantity and their length of presence in the host.


Subject(s)
Antigens, Bacterial/immunology , Borrelia burgdorferi Group/immunology , Lymphocytes/immunology , Cells, Cultured , Humans , Immune Tolerance/immunology , Interleukin-2/analysis , Lyme Disease/immunology , Lymphocyte Activation , Mitogens , Subcellular Fractions
20.
Int J Oncol ; 4(2): 417-21, 1994 Feb.
Article in English | MEDLINE | ID: mdl-21566940

ABSTRACT

Release of DNA fragments into the culture supernatant of human promyelocytic cell line HL-60 was investigated. The released DNA has previously been shown to have a strong immunosuppressive effect on the proliferation of mitogen-stimulated human peripheral lymphocytes and some cancer cell lines. In this study, HL-60 cells were cultured for four days in serum-free medium and the amount of extracellular nucleic acid was monitored daily. Nucleic acids were isolated by phenol/chloroform extractions, followed by ethanol precipitations. A similar amount of DNA was identified in the HL-60 culture supernatant regardless of whether the cells were incubated for one day or up to four days. Also, the same amount of DNA was isolated from culture supernatants after washing the cells daily and reincubating into the fresh medium. During the first 8 hours of incubation no DNA material was detected in the culture supernatant, whereas at 24 h the concentration of the extracellular DNA reached a plateau. The data suggest the extracellular DNA is not accounted for totally by DNA from dying cells, and a regulatory mechanism may be involved which controls the release of DNA into the medium.

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