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Animal models have been proven useful in elucidating the details of interaction between pathogenic bacteria and their human hosts, in addition to assessing the efficacy of therapeutic compounds and vaccines. In this study, we investigate the colonization of Helicobacter pylori (H. pylori) in experimentally-infected guinea pigs over a six-month period. Materials and Methods: A bacterial suspension was prepared by mixing four H. pylori isolates obtained from patients diagnosed with gastric ulcer. Within a one week period, five female guinea pigs were dosed orally with bacterial suspension for a total of three times. One control animal was garaged with normal saline. Stool samples were collected at two-week intervals for six months. We used PCR, the stool antigen test, and indirect immunofluorescence assay (IFA) to assess samples for the presence of H. pylori. Stomachs obtained from two chloroform-killed animals, at 8 and 24 weeks, were investigated for histopathologic changes. Results: H. pylori 16S rDNA was amplified from the stool samples of five guinea pigs. The stool antigen test was also positive in all five animals. IFA demonstrated the presence of H. pylori antigens in the stools from all five animals. PCR, stool antigen test and IFA results showed no H. pylori in the stool of the control animal. We observed infiltration of mature lymphocytes and plasma cells in the stomachs of animals killed at 8 and 24 weeks. Conclusion: The occurrence of H. pylori 16S rDNA and antigens in stool samples of guinea pigs demonstrated persistent colonization of H. pylori in the stomachs of guinea pigs. Histopathological findings have confirmed mild-severe gastritis induced by the bacterial infection. The stomach of a guinea pig is similar to the human stomach, in that it is sterile, lined by glandular epithelium, lacks a vitamin C synthesizing system and produces the cytokine interleukin-8. Accordingly, the guinea pig can be considered an appropriate animal model for long-term experiments to follow the process of H. pylori pathogenesis or to assess the efficacy of antibiotics or vaccines. [ABSTRACT FROM AUTHOR]

Background: In human leishmaniasis Th1/Th2 dichotomy similar to murine model is not clearly defined and surrogate marker(s) of protection is not yet known. In this study, Th1/Th2 cytokines (IL-5, IL-10, IL-13 and IFN-γ) profile induced by purified CD4+/CD8+ T cells in response to Leishmania antigens were assessed at transcript and protein levels in 14 volunteers with a history of self-healing cutaneous leishmaniasis (HCL) and compared with 18 healthy control volunteers. Methodology/Principal Findings: CD4+/CD8+/CD14+ cells were purified from peripheral blood using magnetic beads; CD4+/CD8+ T cells were co-cultured with autologous CD14+ monocytes in the presence of soluble Leishmania antigens (SLA). Stimulation of either CD4+ T cells or CD8+ T cells of HCL volunteers with SLA induced a significantly (P<0.05) higher IFN-γ production compared with the cells of controls. Upregulation of IFN-γ gene expression in CD4+ cells (P<0.001) and CD8+ cells (P = 0.006) of HCL volunteers was significantly more than that of controls. Significantly (P<0.05) higher fold-expression of IFN-γ gene was seen in CD4+ cells than in CD8+ cells. In HCL volunteers a significantly (P = 0.014) higher number of CD4+ cells were positive for intracellular IFN-γ production than CD8+ cells. Conclusions/Significance: Collectively, the volunteers have shown maintenance of specific long-term immune responses characterized by a strong reaction to leishmanin skin test and IFN-γ production. The dominant IFN-γ response was the result of expansion of both CD4+ and CD8+ T cells. The results suggested that immune response in protected individuals with a history of zoonotic cutaneous leishmaniasis (ZCL) due to L. major is mediated not only through the expansion of antigen-specific IFN-γ producing CD4+ Th1 cells, but also through IFN-γ producing CD8+ T cells. Author Summary: Cutaneous leishmaniasis (CL) is usually a self-healing skin lesion caused by different species of Leishmania parasite. Resistance and susceptibility of mice to Leishmania major infection is associated with two types of CD4+ T lymphocytes development: Th1 type response with production of cytokine IFN-γ is associated with resistance, whereas Th2 type response with production of cytokines IL-4 and IL-5 is associated with susceptibility. A clear Th1/Th2 dichotomy similar to murine model is not defined in human leishmaniasis and we need as much information as possible to define marker(s) of protection. We purified CD4+/CD8+ T cells, stimulated them with Leishmania antigens and analysed gene and protein expression of Th1/Th2 cytokines in volunteers with a history of self-healing CL who are presumed to be protected against further Leishmania infection. We have seen significant upregulation of IFN-γ gene expression and high IFN-γ production in the Leishmania stimulated CD4+ T cells and CD8+ T cells. We concluded that both antigen-specific IFN-γ producing CD4+ Th1 cells and IFN-γ producing CD8+ T cells contribute to the long term protection in individuals with a history of CL. This proves the importance of CD8+ T cells as a source of IFN-γ in Th1-like immune responses. [ABSTRACT FROM AUTHOR]

Background: In human leishmaniasis Th1/Th2 dichotomy similar to murine model is not clearly defined and surrogate marker(s) of protection is not yet known. In this study, Th1/Th2 cytokines (IL-5, IL-10, IL-13 and IFN-γ) profile induced by purified CD4+/CD8+ T cells in response to Leishmania antigens were assessed at transcript and protein levels in 14 volunteers with a history of self-healing cutaneous leishmaniasis (HCL) and compared with 18 healthy control volunteers. Methodology/Principal Findings: CD4+/CD8+/CD14+ cells were purified from peripheral blood using magnetic beads; CD4+/CD8+ T cells were co-cultured with autologous CD14+ monocytes in the presence of soluble Leishmania antigens (SLA). Stimulation of either CD4+ T cells or CD8+ T cells of HCL volunteers with SLA induced a significantly (P<0.05) higher IFN-γ production compared with the cells of controls. Upregulation of IFN-γ gene expression in CD4+ cells (P<0.001) and CD8+ cells (P = 0.006) of HCL volunteers was significantly more than that of controls. Significantly (P<0.05) higher foldexpression of IFN-γ gene was seen in CD4+ cells than in CD8+ cells. In HCL volunteers a significantly (P = 0.014) higher number of CD4+ cells were positive for intracellular IFN-γ production than CD8+ cells. Conclusions/Significance: Collectively, the volunteers have shown maintenance of specific long-term immune responses characterized by a strong reaction to leishmanin skin test and IFN-γ production. The dominant IFN-γ response was the result of expansion of both CD4+ and CD8+ T cells. The results suggested that immune response in protected individuals with a history of zoonotic cutaneous leishmaniasis (ZCL) due to L. major is mediated not only through the expansion of antigenspecific IFN-γ producing CD4+ Th1 cells, but also through IFN-γ producing CD8+ T cells. [ABSTRACT FROM AUTHOR]

Background: Allergic rhinitis is a common disorder with great morbidity. Its prevalence has increased during recent years, therefore attracting attentions to its mechanisms. Type 2 cytokines play a major role in allergies. It has been proposed that Natural killer (NK) cells may be able to produce type 2 cytokines. This study was done to evaluate NK cells number and subtypes in patients with allergic rhinitis, comparing healthy subjects. Methods: In a case control study, patients with allergic rhinitis were compared to healthy non-atopic subjects. Allergic rhinitis was diagnosed according to ARIA guidelines. NK cells quantity was studied by staining of peripheral blood mono nuclear cells with anti-CD16-FITC and anti-CD56-PE and evaluated by two color flowcytometry. Intracellular cytokines were evaluated by tri-color flowcytometry. NK cells were separated by magnetic beads, and cultured for 72 hours. Secretion of IL-4, IL-5, IL-10, IL-13, and IFN-γ was measured by ELISA, in stimulated and unstimulated conditions. Results: Patients had more CD16+ CD56+ NK cells than control group. IL-4+ NK cells were significantly higher in patients (p<0.001), but the number of IFN-γ+ NK cells was not different. Cytokine secretion of NK cells was similar in case and control groups. Although IL-13 level after stimulation seemed higher in patients, the difference was not significant. Conclusion: NK cells number is increased in patients with allergic rhinitis and a considerable number of them produce IL-4. [ABSTRACT FROM AUTHOR]

Introduction. We aimed to identify immune status of the stable kidney allografts from the point of some cellular changes that may occur after transplantation. Materials and Methods. This study considered 57 patients with no rejection during the 6 months after transplantation. Flow cytometric frequencies of circulatory CD4+CD25+FoxP3+ and CD8+CD28- regulatory T cells (Treg) as well as myeloid dendritic cells type 1 (MDC1) and type 2 (MDC2) and plasmacytoid dendritic cells (PDC) were measured before transplantation and 2 weeks and 1, 3, and 6 months after transplantation. Using adjusted model of repeated measure analysis, we assessed the influence of different parameters on different cell subsets. Results. The mean number of Tregs and PDCs decreased 2 weeks after transplantation and then increased as they reached their values before transplantation within a few months after transplantation. The mean MDC1s increased during 2 weeks and then decreased to its before-transplantation values within 6 months. The frequency of Tregs (r = 0.90) and MDC1s (r = 0.75) at month 3 could strongly predict their frequencies at month 6. Different variables including family relationship between donor and recipient, glomerular filtration rate, and human leukocyte antigen antibody mismatch did not change the frequency of different cell subsets during the time. Conclusions. The dynamism and circulatory changes in the frequency of Tregs and PDCs are opposite to MDCs after kidney transplantation. We describe these changes in a group of patients with stable graft; however, our study does not render any idea in patients with unstable or rejecting grafts. [ABSTRACT FROM AUTHOR]

Background: Proton pump inhibitors (PPIs) with lipophilic nature may interact with lipid components of H. pylori cell membrane, disrupting cell structure and viability. In this study, the effect of PPIs on fatty acid and cholesterol components of H. pylori cell membrane was assessed. Methods: One H. pylori isolate was treated with 1X and 2X MICs (μg/mL) of lansoprazole (LPZ: 8 and 16) and pantoprazole (PAN: 128 and 256) in brain heart infusion broth plus serum. Treated H. pylori was cultured on brucella blood agar (BBA) and tetrazolium egg yolk agar (TEYA). Bacterial cells stained with Live/Dead kit were examined by fluorescent microscopy. Fatty acid and cholesterol contents of treated H. pylori were measured by gas chromatography. Results: PPI-treated H. pylori did not grow on BBA but grew on TEYA. Fluorescent microscopy showed H. pylori stained red. Analyses showed high frequency of saturated fatty acids, C14:0, C16:0 and C18:0. Among unsaturated fatty acids, C18:1 and C18:2c were increased, while five were eliminated and five were synthesized de novo. Cholesteryl-6-O-tetradecanoyl-α-D- glucopyranoside was detected as the only glycosylated cholesterol in treated H. pylori. Growth of PPI-treated H. pylori on cholesterol-rich TEYA showed that occurrence of cholesterol can reverse the growth inhibition by PPIs. Red- bacilli form of H. pylori showed dye entry through damaged cell membrane without lysis. Conclusion: Incorporation of lipophilic PPI into H. pylori cell membrane disrupted lipids and inhibited growth. However, H. pylori adjusted the defected membrane by replacing the lipid components and resisted lysis. [ABSTRACT FROM AUTHOR]

Introduction: Candiduria is common in the hospitalized patients. This study aimed to quantify interleukin (IL)-17 and IL-22 levels in urine of candiduric patients.Materials and Methods: A case-control study was conducted on inpatients at Hashemi Nejad Kidney Center. Thirty-four patients were identified with Candida species in their urine samples (> 103 colony-forming units per milliliter and presence of Candida species only). Urine samples with concomitant infections were excluded. Thirty-four patients with negative direct examination and culture were included as the control patients. Interleulin-17 and IL-22 levels were measured in the lyophilized and nonlyophilized urine. The relevant cytokine titers of the two groups were compared, and the association of cytokine elevation and candiduria was investigated.Results: The majority of the candiduric patients were from the intensive care and urology units of women. Only 4 patients (11.7%) manifested fever and dysuria. Massive leukocyturia was observed in 4 patients. Candida glabrata was the most commonly isolated species (44%). Levels of the urine IL-17 and IL-22 were significantly elevated in the candiduric patients, when compared to the noncandiduric controls. While an increased IL-17 level was significantly associated with candiduria (odds ratio, 1.09; 95% confidence interval, 1.003 to 1.17; P = .04), an increased IL-22 level was not. The results showed that lyophilized urine samples maximized the detection power of urinary cytokines.Conclusions: Our results indicated that direct examination, fungal urine culture, and investigation of urine IL-17 and IL-22 levels are useful tools for diagnosis of Candida urinary tract infection. [ABSTRACT FROM AUTHOR]

Background Leukocyte infiltration into the graft has pivotal effects on kidney transplantation outcome. The present study sought to determine whether the expression of sequential chemokine receptors on CD4 + and CD8 + T cells in human renal allograft can predict clinical episodes. Methods Blood samples from 52 consecutive renal transplant patients were evaluated at the time of transplantation and at three times (2, 90 and 180 days) after transplantation to analyze the expression of CCR1 and CXCR3 on CD4 + and CD8 + T cells by flowcytometry. A total of 30 biopsies, including protocol biopsy (n = 24) and cause biopsy (n = 6), were investigated according to the Banff criteria. Results The mean percentage of CD4 + and CD8 + T cells expressing CCR1 was significantly increased in patients with allograft dysfunction (n = 25) (p = 0.006, p = 0.004). The mean fluorescence intensity of CXCR3 on CD4 + and CD8 + T cells were found to be significantly higher in graft dysfunction than that in well-functioning grafts. (p < 0.001, p = 0.007). Receiver Operating Characteristic (ROC) Curve Analysis showed that the calculated AUC was 0.86 at the third month for CD4 + CCR1 + and CD8 + CCR1 + (p < 0.001). Multiple logistic regression analysis showed that an increase in CD4 + expressing CXCR3 leads to a lower risk of graft dysfunction (OR = 0.37), while an increase in CD8 + expressing CCR1 results in a higher risk of graft dysfunction (OR = 3.66). Conclusion During renal transplantation, CD4 + and CD8 + T cells expressing CCR1 were increased in patients who developed graft dysfunction. These findings may prospectively predict allograft dysfunction, and help elucidate the underlying pathogenic mechanisms. [ABSTRACT FROM AUTHOR]

Abstract: Recovery from CL is usually accompanied with long-lasting protection and induction of strong immune response. The phenotypes, generation and maintenance of central (=TCM) and effector (=TEM) memory T cell subsets in human leishmaniasis are not well known. Profile of T cell subsets were analyzed on peripheral CD8+ T cells from volunteers with history of cutaneous leishmaniasis (HCL). In HCL and control groups, mean frequencies of CCR7+CD45RA+CD8+ naïve and CCR7−CD45RA−CD8+ TEM cells were higher than other subsets before culture, but after stimulation with soluble Leishmania antigen, the frequency of naïve T cells was significantly decreased and the frequency of TEM cells was significantly increased. TEM phenotype composed the highest portion of proliferating Carboxy Fluorescein diacetate Succinimidyl Ester (CFSE)-dim population which was significantly higher in HCL volunteers than in control group. Stimulation of isolated CD8+ memory T cells, but not naïve T cells, from HCL volunteers induced a significantly higher IFN-γ production compared with that of healthy controls. Intracellular IFN-γ staining provided the same result. Memory population is shown to be responsible for Leishmania-induced IFN-γ production. Leishmania-reactive proliferating TEM cells were identified as the most frequent subset which may play a role in recall immune response and protection against Leishmania infection. [Copyright &y& Elsevier]

HLA-G is normally expressed on human trophoblast cells. It is a non-classical MHC molecule class I b. The role of HLA-G in diabetic type 1 is not known. We investigated the role of IFN-beta in induction HLA-G expression on the monocyte derived dendritic cells (DC) in diabetes type 1. Treatment of dendritic cell with IFN-beta in vitro from diabetic patients (n=20) and normal subjects (n=20) resulted to the production and expression of HLA-G on these cells from both groups. However, comparison of DC from the diabetic patients with DC from the controls revealed lower levels of HLA-G molecules in DC from diabetic patients. Using mixed lymphocyte reaction (MLR), it was found that DC expressing HLA-G mediated the inhibition of autologous T cell activation. It is concluded that IFN-beta can increase HLA-G in DC from diabetic patients; subsequently it may prevent the immune regularly pathway in the diabetic pathogenesis.

Introduction: This study aimed to compare urinary Tamm-Horsfall protein (THP), citrate, and other inhibitors and promoters of stone formation in calcium stone formers with those in healthy individuals., Materials and Methods: From January 2002 to June 2004, 100 calcium stone formers (mean age, 38.6 +/- 10.3 years) who had at least 2 episodes of calcium stone formation were compared with 100 healthy individuals (mean age, 33.8 +/- 9.7 years). Their 24-hour urine THP (using the sodium dodecyl sulfate polyacrylamide gel electrophoresis method), citrate, calcium, uric acid, oxalate, and magnesium values were measured and compared., Results: The mean 24-hour urine THP was 3.3 +/- 8.1 mg in patients in the study group and 4.6 +/- 19.2 mg in controls (P = 0.5). However, THP in individuals with and without bacteriuria was significantly different (15.8 +/- 33.6 versus 2.6 +/- 10.2, P < 0.001). Mean 24-hour urinary calcium, citrate, and oxalate values were 232.6 +/- 95.3 mg and 177.8 +/- 82.7 mg (P < 0.001), 132 +/- 103.2 mg and 395 +/- 258.5 mg (P < 0.001), and 18.9 +/- 22.5 mg and 10.4 +/- 8.5 mg (P < 0.001) in patients in the study and control groups, respectively. There was a significant positive correlation between urinary citrate and promoters of stone formation, including urinary calcium, oxalate, and uric acid, in patients in the control group, but not in patients in the study group., Conclusion: THP in the urine of stone formers is not quantitatively different from that of healthy individuals, but it is different in patients with bacteriuria. Increased urinary excretion of calcium, oxalate, and uric acid in stone formers with no increase in urine citrate may play a role in the pathogenesis of recurrent stone formation.