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Biomedical subjects

Mirjana Hahn-Zoric

Publications and source records attributed to Mirjana Hahn-Zoric.

15 recordsLinked to original sources

Interferon-gamma dose-dependently inhibits prostaglandin E2-mediated dendritic-cell-migration towards secondary lymphoid organ chemokines.

Monocyte-derived human dendritic cells (MoDCs) are increasingly applied as cellular vaccines for cancer patients. Important features for their efficacy include high migratory responsiveness to lymph node-chemokines and most likely their ability to produce bioactive IL-12 p70 upon subsequent contact with CD40 ligand-expressing T-cells. The current standard DC-maturation cocktail for clinical trials is inflammatory cytokines (TNF-alpha, IL-1beta and IL-6) combined with prostaglandin E(2) (PGE(2)), inducing phenotypically mature MoDCs with high migratory responsiveness to CCR7 ligands. This cocktail does not, however, induce or prime for production of IL-12 p70. Addition of IFN-gamma to PGE(2)-containing maturation cocktails has been shown to prime for substantial production of IL-12 p70 by subsequent CD40 ligation, but the impact of IFN-gamma on phenotypic maturation and migratory responsiveness induced by PGE(2)-containing inflammatory stimuli still remains elusive. Here, we demonstrate that addition of IFN-gamma to the standard maturation cocktail decreased CCR7 mRNA and down-regulated CCR7 expression on MoDCs in a dose-dependent manner. Moreover, addition of IFN-gamma was found to suppress MoDC-migration towards the CCR7-ligands CCL19 and CCL21. These novel findings indicate that addition of IFN-gamma to DC-maturation stimuli may have no beneficial impact on MoDC-vaccine efficiency and further implicate IFN-gamma as a negative feedback factor in DC migration towards draining lymph nodes when full-blown Th1-type responses are established. Such mechanism may restrict an uncontrolled and potentially harmful amplification of the adaptive Th1 response.

Antigens, CD↗

Common variations in the IL4R gene affect splicing and influence natural expression of the soluble isoform.

We previously found the soluble interleukin 4 receptor (sIL4R) to be differently expressed in allergic asthma patients compared to healthy individuals. Here we present data demonstrating the involvement of the sequence variations, c.912-1003A > G, c.912-833T > C, c. 912-630A > G, and c.912-577A > G, in the expressional regulation of IL4R splice variants. By using an IL4R minigene construct, genomic DNA and mRNA from asthma patients and nonasthmatic individuals, we analyzed the function of four highly-linked SNPs, flanking the alternatively-spliced exon in the IL4R gene. Results from the minigene assay showed that the form containing the minor alleles significantly decreased the expression of the soluble IL4R (exon 8+) variant, a decrease that could only be seen in the major construct after increasing amounts of either the splicing factor SRp20, or YT521-B. Analysis of mRNA expression in our human material confirmed the results, demonstrating lower expression of the sIL4R in patients and controls carrying the minor alleles. Together these results show sequence variations as a possible way of altering alternative splicing selection of IL4R in vivo.

Adolescent↗

Avidity of tetanus and Hib antibodies after childhood acute lymphoblastic leukaemia - implications for vaccination strategies.

AIM: To investigate the possible relationship between serum levels and avidities of antibodies against tetanus toxoid (TT) and Haemophilus influenzae type b (Hib) in children that were vaccinated after treatment for childhood acute lymphoblastic leukaemia (ALL). METHODS: The study groups were 31 paediatric patients with ALL and 18 healthy controls. All subjects were vaccinated with TT and a protein conjugated Hib vaccine. Antibody levels were analysed at three time points: At diagnosis of ALL, after cessation of treatment before vaccination and three weeks after vaccination. Avidity was measured twice, with a thiocyanate elution assay, at diagnosis of ALL and three weeks after vaccination. RESULTS: There was a correlation between level and avidity of tetanus antibodies after vaccination (r(s) = 0.59, P < 0.001). In the standard-risk and intermediate-risk ALL groups, all patients responded with protective levels of tetanus antibodies with normal avidity. In the high-risk ALL group 7/9 patients had subprotective levels of tetanus antibodies after vaccination and concomitantly the lowest avidity, implying poor protection against tetanus. No patients were found with low levels and low avidity of anti-Hib IgG, and 29/31 patients had full protection after a single dose of conjugated Hib-vaccine. CONCLUSION: The vaccination strategy after childhood ALL must be different for low-risk and high-risk ALL groups, since the high-risk group fail to elicit a recall response to tetanus.

Adolescent↗

Cytokines in the placenta of Pakistani newborns with and without intrauterine growth retardation.

Although intrauterine growth retardation (IUGR) is a major risk factor for increased neonatal mortality and morbidity, the mechanisms behind it are not clear. We analyzed cytokine gene expression and gene polymorphisms in infants with and without IUGR in Pakistan, where IUGR is very common. 45 IUGR and 55 control mother/infant pairs were studied. mRNA for IL-10, IL-8, TNF-alpha, TGF-beta, IL-6, IL-4, IL-1beta, IL-12, IFN-gamma and GAPDH was quantified with RT-PCR from placenta. Cytokine and cytokine receptor gene polymorphisms for -1087IL10, -308TNFA, -174IL6, +915TGFB1, intron 2 IL1RN, +36TNFR1, 150V IL4RA and -159CD14 were determined from genomic DNA. The serum levels of IL-1beta, IL-6, IL-8, IL-10, IL-12, TNF-alpha and TGF-beta were measured. There was a significant decrease of IL-10 and IL-12, but increase of TGF-beta in the decidua and similarly decrease of IL-10, but increase of TGF-beta in the trophoblasts of the IUGR placentas compared with the non-IUGR placentas. We found significantly lower levels of IL-1beta in serum from the mothers of the IUGR infants and of TGF-beta in serum of the infants with IUGR compared with the non-IUGR infants. We note that the IL-10 mRNA expression in the decidua was down-regulated, but the TGF-beta mRNA up-regulated in IUGR placentas of mothers from a population with multiple risk factors for IUGR. We propose that the low IL-10 in the placenta may be involved in the pathogenesis of IUGR and might possibly be treatable.

Base Sequence↗

Association of the -159 CD14 gene polymorphism and lack of association of the -308 TNFA and Q551R IL-4RA polymorphisms with severe chronic periodontitis in Swedish Caucasians.

BACKGROUND: Severe forms of periodontitis are suggested to have a genetic basis. OBJECTIVE: The aim of the present investigation was to study the association of gene polymorphisms related to some immune regulation components (G-308A TNFA, Q551R IL-4RA and C-159T CD14) with severe chronic periodontitis. MATERIALS AND METHODS: Sixty patients (aged 36-74 years; mean 54.5+/-8.5) with severe and generalized chronic periodontitis were included. The patients exhibited bone loss >50% at all teeth. Thirty-nine periodontally healthy subjects between 35 and 78 years of age (mean 51.0+/-10.9) were recruited as controls. DNA was isolated from peripheral blood cells and genotyping was performed by combination of PCR and restriction endonuclease mapping. RESULTS: While gene polymorphisms for TNFA and IL-4RA did not show any association with severe chronic periodontitis, the analysis of the -159 CD14 gene polymorphism revealed significant differences between test and control groups. The proportion of subjects that exhibited the TT genotype was significantly smaller in the group with severe periodontitis than in periodontal healthy group (p=0.028; Fisher's exact test). The C allele carriage was 90% in the periodontitis group and significantly higher than in the healthy control group (72%). CONCLUSION: It is suggested that the -159 CD14 gene polymorphism is associated with chronic periodontitis in Caucasian subjects of a north European origin.

Adult↗

Impaired kidney graft survival is associated with the TNF-alpha genotype.

BACKGROUND: The TNF2 allele at position -308 of the tumor necrosis factor (TNF)-alpha gene is associated with high TNF production. The purpose was to study the association of this gene polymorphism with rejection episodes and graft survival after kidney transplantation. METHODS: A retrospective analysis of transplant outcomes of patients who only had been treated with one single form of immunosuppression consisting of cyclosporine, azathioprine, and prednisolon was performed. RESULTS: We found that 115 (73%) patients had the TNF1/TNF1 genotype, whereas 42 (27%) were TNF2 positive. There was no difference in the overall acute rejection frequency between these two groups (50% in each), but our data showed a non-significant tendency towards a higher frequency of steroid resistant rejections in the TNF2 positive group (57% vs. 40%). There was no significant difference in graft survival between the two genotype groups, although an early tendency towards worse survival was seen in TNF2 recipients. However, the TNF2 positive recipients with rejection episodes had far worse graft survival compared with the TNF1/TNF1 recipients with rejection episodes (P<0.02). No difference was seen between the two genotype groups in patients without rejection episodes. CONCLUSION: Our data propose that potentially high TNF producers with the TNF2 allele do not have an increased risk for rejection episodes, but if rejection episodes occur, they have a significantly increased risk for early graft loss. TNF production may intensify rejection, but is not a primary factor for the induction of such acute immune activation.

Acute Disease↗

Intensive treatment for childhood acute lymphoblastic leukemia reduces immune responses to diphtheria, tetanus, and Haemophilus influenzae type b.

OBJECTIVES: Immunity to diphtheria toxoid (D), tetanus toxoid (T), and Haemophilus influenzae type b (Hib) is affected in children with acute lymphoblastic leukemia (ALL). The aims were to examine immunity and to compare the response to immunization at 1 or 6 months after treatment. METHODS: Thirty-one patients were immunized with DT and conjugated Hib vaccine (ActHib) at 1 month or 6 months after treatment of ALL with the NOPHO 92 protocol. Antibody levels were determined before and 3 weeks after vaccination. Specific T and Hib antibody-secreting cells of IgG/IgA/IgM isotypes were analyzed in peripheral blood using an ELISPOT technique. RESULTS: All specific antibody levels decreased during ALL treatment, and protective levels after treatment were noted for 17% against D, 33% against T, and 100% against Hib. No high-risk patient had full D or T protection after treatment. After vaccination all the standard- and intermediate-risk patients achieved full protection against D, T, and Hib. The high-risk group showed insufficient immune response (full protection after vaccination: D 56%, T 22%, Hib 78%). No difference was found between vaccination at 1 month or 6 months after treatment. The poor antibody production in the high-risk group correlated to low numbers of antibody-secreting cells. CONCLUSIONS: Nonprotective antibody levels against D, T, and Hib after childhood ALL are more common than previously thought. Insufficient immune response was restricted to the high-risk group and was related to a low number of memory B cells in this study. Immunizations should be included in follow-up after childhood ALL, and the policy should be adapted to treatment intensity.

Adolescent↗

Polymorphism in promoter region of IL10 gene is associated with rheumatoid arthritis in women.

OBJECTIVE: Rheumatoid arthritis (RA) is a genetically complex disease with many possible phenotypes. We investigated IL10 and TNFA gene polymorphisms in a group of Swedish women and men with RA compared with healthy individuals to estimate combinations of alleles specific for the disease. METHODS: We analyzed 264 patients with RA and 286 healthy controls for biallelic single-nucleotide polymorphisms in the -308 position of the TNFA and in the -1087 position of the IL10 gene by polymerase chain reaction with restriction endonuclease mapping. RESULTS: The frequencies of the -308 TNFA genotypes were not different in women and men with RA in comparison to the controls. In contrast, frequencies of the GG, AG, and AA -1087 IL10 genotypes were significantly different in women in the investigated groups: 26%, 58%, and 15% for RA patients and 24%, 54%, and 28% for the controls (chi-square = 8.18, p < 0.02). We confirmed this finding in a separate dataset of female patients and controls. The frequencies of the IL10 genotypes in men were similar in the patients and controls. We found no differences in the distribution of the TNFA or IL10 genotypes in relation to rheumatoid factor in the patients. CONCLUSION: On the basis of IL10 polymorphism, female patients with RA seem to represent a separate disease subgroup.

Arthritis, Rheumatoid↗

Association of the -1087 IL 10 gene polymorphism with severe chronic periodontitis in Swedish Caucasians.

BACKGROUND: Severe forms of periodontitis are suggested to have a genetic basis. OBJECTIVE: The aim of the present investigation was to study association of an IL10 gene polymorphism (G to A transition at the -1087 position) with severe chronic periodontitis. MATERIALS AND METHODS: Two groups of Swedish Caucasian subjects were included. One group consisted of 60 patients (aged 36-74 years; mean 54.5+/-8.5) with severe and generalized chronic periodontitis. The patients exhibited bone loss >50% at all teeth. Thirty-nine periodontally healthy subjects between 35-78 years of age (mean 51.0+/-10.9) were also recruited. DNA was isolated from peripheral blood cells and genotyping was performed by combination of PCR with restriction endonuclease mapping. RESULTS: The proportion of subjects that exhibited the GG genotype was significantly larger in the group with severe periodontitis than in the periodontally healthy group. The difference regarding the occurrence of the GG genotype between the two groups was more conspicuous in non-smokers and yielded an odds ratio of 6.1. The G allele carriage in non-smokers was >90 % in the periodontitis group and was significantly higher than in the healthy controls. CONCLUSION: It is suggested that the -1087 IL10 polymorphism in Caucasian subjects of a north European origin is associated with severe chronic periodontitis.

Adenine↗

Lactoferrin down-regulates the LPS-induced cytokine production in monocytic cells via NF-kappa B.

Lactoferrin, a glycoprotein present in milk, mucosal secretions and neutrophils contributes to host defense. We have previously shown that orally given milk lactoferrin (LF) mediates anti-infectious and anti-inflammatory activities in vivo. Moreover, we have shown that LF could inhibit the LPS-induced IL-6 secretion in a human monocytic cell line, THP-1. This observation was expanded in the present study investigating the capacity of LF to inhibit cytokine mRNA expression and the involvement of nuclear transcription factor kappa B (NF-kappa B). Cells (THP-1 and Mono Mac 6 monocytic cell lines) were stimulated with Escherichia coli LPS (5-10 ng/10(6) cells) and LF was added (50-500 microg/10(6) cells) 30 min before, or after the LPS addition. By a semiquantitative RT-PCR lower levels of TNF-alpha, IL-1 beta, IL-6, and IL-8 mRNA expression were detected at the peak of the expression in THP-1 cells treated with LF. The reduction in the cytokine expression was followed by a similar reduction in the secreted cytokines as analyzed by ELISA. LF down-regulated also the IL-10 secretion (detected only in LPS-stimulated Mono Mac 6 cells). A similar level of inhibition of these cytokines was detected regardless of the time at which LF was added to the cells in relation to LPS. In addition, LF was internalized into cells and detected in the nucleoli as determined by immunostaining and immunofluorescence. Moreover, by electrophoretic mobility shift assay (EMSA) analysis LF decreased the LPS-induced binding of NF-kappa B to the TNF-alpha promoter. The results show that LF down-regulates the LPS-induced cytokine production in monocytic cells. The inhibitory mechanism is suggested to involve the interference of LF with NF-kappa B activation.

Cytokines↗

Long term enhancement of the IgG2 antibody response to Haemophilus influenzae type b by breast-feeding.

SUBJECTS: Sets of sera were obtained from 30 children <6 years of age with invasive type b (Hib) infection and their mothers. Duration and mode of breast-feeding were monitored. Titers of IgG1, IgG2, IgA and IgM antibodies against Hib capsular polysaccharide were determined in sera taken during the acute illness and during early and late convalescence. RESULTS: Children 18 months or older with longer durations of exclusive breast-feeding (13 weeks or more; mean, 19.3 weeks) had higher Hib antibody concentrations of the IgG1, IgG2, IgA and IgM isotypes than those with a shorter duration of exclusive breast-feeding (<13 weeks; mean, 5.4 weeks). The difference was greatest for the IgG2 isotype. In regression analyses the association between the duration of exclusive breast-feeding and the anti-Hib IgG2 concentration was significant when breast-feeding, type of Hib infection, maternal Hib antibody titer and age were used as explanatory factors. In the group of 14 children <18 months of age no significant differences were noted. DISCUSSION: This study indicates the presence of a long lasting enhancing effect of breast-feeding on the antibody response to Hib in children, in particular on IgG2 Hib antibody production. This may result from the content in the milk of IFN-gamma and IFN-gamma-producing cells and possibly other factors, which can support IgG2 antibody production.

Age Factors↗

Aberrations in placental cytokine mRNA related to intrauterine growth retardation.

During normal pregnancy, a predominance of Th2 type cytokines prevails and is considered to protect the fetus. Animal experiments suggest that an increase of Th1 type cytokines may instead have deleterious effects. We have studied with the reverse transcription PCR technique mRNA for IL-1alpha, IL-1beta, IL-6, IL-8, IL-10, transforming growth factor-beta, tumor necrosis factor-alpha, and interferon-gamma in placentas from full-term appropriately grown newborns, newborns with intrauterine growth retardation (IUGR) and newborns who were only small for gestational age. The mRNA for IL-10 was significantly reduced in the IUGR placentas (p < 0.05), whereas the mRNA for IL-8 was significantly higher (p < 0.05) for the IUGR cases compared with the full-term neonates. It might be that reduced IL-10 in the placenta is involved in the pathogenesis of IUGR.

Animals↗

Breast-feeding, a complex support system for the offspring.

The newborn has an immune system, very limited in size at birth and its postnatal expansion and maturation takes time. In the meantime the transplacental IgG antibodies from the mother play an important role for the protection of the infant. However, these antibodies act in tissues and induce inflammation and are energy-consuming. In contrast, the milk secretory IgA antibodies stop microbes already on the mucosa preventing infection, tissue engagement and energy loss. In addition, the milk contains many protective factors such as lactoferrin and oligosacharides functioning as analogues for microbial receptors preventing mucosal attachment, the initial step of most infections. As a result, breast-feeding significantly reduces the risk of neonatal septicemia, respiratory tract infections, otitis media, diarrhea, urinary tract infections, infection-induced wheezing and necrotizing enterocolitis. Via several mechanisms it seems that human milk can actively stimulate the immune system of the breast-fed infant. This reduces the risk of infections like otitis media, respiratory tract infections, diarrhea and infection-induced wheezing for several years after the termination of breast-feeding. Furthermore, it seems that breast-feeding decreases the risk of attracting celiac disease and allergic diseases. The latter has been much debated, but a recent critical review of published reports gives good support for long-term protection of allergic diseases, especially in high-risk children.

Breast Feeding↗