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排序方式: 共有650条查询结果,搜索用时 15 毫秒
1.
Effects of preinduced Candida-specific systemic cell-mediated immunity on experimental vaginal candidiasis. 总被引:6,自引:7,他引:6
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It has been postulated that systemic cell-mediated immunity (CMI) is an important host defense factor against recurrent vaginal infections caused by Candida albicans. Using an estrogen-dependent murine model of vaginal candidiasis, we have previously shown that mice inoculated vaginally with C. albicans acquire a persistent vaginal infection and develop Candida-specific Th1-type systemic CMI. In the present study, experimental vaginitis was monitored in the presence of preinduced systemic Candida-specific CMI. Mice immunized systemically with C. albicans culture filtrate antigens (CaCF) in complete Freund's adjuvant (CFA) had Th1-type reactivity similar to that of vaginally infected mice. CaCF given to mice intravenously induced Candida-specific suppressor T (Ts) cells. Mice preimmunized with CaCF-CFA and given a vaginal inoculum of C. albicans had positive delayed-type hypersensitivity (DTH) reactivity from the time of vaginal inoculation through 4 weeks. Conversely, mice infected in the presence of Ts cells had significantly reduced DTH responses throughout the 4-week period in comparison with naive infected mice. However, the presence of Th1-type Candida-specific DTH cells or Ts cells, either induced in mice prior to vaginal inoculation or adoptively transferred at the time of inoculation, had no effect on the vaginal Candida burden through 4 weeks of infection. A similar lack of effects was obtained in animals with lower Candida population levels resulting from a reduction in or absence of exogenous estrogen. These results suggest that systemic Th1-type CMI demonstrable with CaCF is unrelated to protective events at the level of the vaginal mucosa. 相似文献
2.
Candida-specific cell-mediated immunity is demonstrable in mice with experimental vaginal candidiasis. 总被引:6,自引:10,他引:6
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Women with recurrent vulvovaginal candidiasis often demonstrate a down-regulation of cell-mediated immunity (CMI) to Candida albicans detected by a lack of cutaneous delayed-type hypersensitivity (DTH) to Candida antigens. However, the role of systemic CMI as a host defense mechanism against recurrent vulvovaginal candidiasis is not well understood, in part because of the lack of a well-defined murine model of vaginal candidiasis. The present study was undertaken to determine: (i) whether soluble Candida culture filtrate antigens (CaCF) could be used to induce and detect Candida-specific CMI in mice and (ii) whether these antigens would be useful in detecting systemic CMI in mice given an experimental Candida vaginal infection. To this end, mice were immunized subcutaneously with CaCF in complete Freund's adjuvant, and within 7 days they developed Candida-specific DTH reactivity detected by footpad swelling (increase in footpad thickness, 0.36 mm) 24 h after footpad challenge with CaCF. Adoptive transfer studies showed that the DTH responsiveness was elicited by CD4+ DTH T cells. In mice given a vaginal inoculum of C. albicans blastoconidia (5 x 10(5)), footpad challenge with CaCF resulted in positive DTH responses (0.24 mm) as early as 1 week, responses similar to immunization in 2 to 3 weeks (0.33 mm), and sustained low levels of DTH reactivity (0.15 mm) through 10 weeks of vaginal infection. Vaginal lavage cultures revealed that peak vaginal Candida burden occurred 1 week post-vaginal inoculation (10(5) CFU) and declined 16-fold by week 10. These results provide evidence that Candida-specific systemic CMI is generated and can be detected longitudinally in mice with Candida vaginitis by a multiantigen preparation of Candida organisms which both initiates and detects Candida-specific CMI. 相似文献
3.
Characterization of CD8+ T cells and microenvironment in oral lesions of human immunodeficiency virus-infected persons with oropharyngeal candidiasis
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Oropharyngeal candidiasis (OPC), the most common oral infection in human immunodeficiency virus-positive persons, correlates with reduced blood CD4+ T cells. In those with OPC, CD8+ T cells accumulate at the lamina propria-epithelium interface at a distance from the organism at the outer epithelium. The present study aimed to characterize the tissue-associated CD8+ T cells and tissue microenvironment in both OPC+ and OPC- persons. The results show that the majority of CD8+ T cells possess the alphabeta T-cell receptor, the thymus-derived alphabeta CD8 antigen heterodimer, and similar levels of the alpha(4)beta(7), alpha(4)beta(1), and alpha(e)beta(7) homing receptors. Studies to evaluate the tissue microenvironment showed that in OPC+ persons, the adhesion molecule for T cells to enter mucosa, mucosal addressin cell adhesion molecule, is significantly increased, whereas E-cadherin, which allows T cells to migrate through mucosa, is significantly decreased compared to OPC- persons. These results continue to support a role for CD8+ T cells against OPC under conditions of reduced numbers of CD4+T cells, with susceptibility to infection potentially associated with a dysfunction in mucosal CD8+ T-cell migration by reduced tissue-associated E-cadherin. 相似文献
4.
Immunohistochemical evaluation of T cells in oral lesions from human immunodeficiency virus-positive persons with oropharyngeal candidiasis
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Myers TA Leigh JE Arribas AR Hager S Clark R Lilly E Fidel PL 《Infection and immunity》2003,71(2):956-963
Oropharyngeal candidiasis (OPC), caused by Candida albicans, is the most frequent opportunistic fungal infection in human immunodeficiency virus (HIV)-positive persons. Although Th1-type CD4(+) T cells are considered important for host defense against mucosal C. albicans infections, there is a paucity of information regarding the presence and/or role of T cells in OPC lesions. In pursuit of this, initial chromophore immunohistochemical studies showed a majority of CD8(+) rather than CD4(+) cells equally distributed throughout the buccal mucosa of OPC(-) persons (HIV(-) or HIV(+)), irrespective of blood CD4(+) cell numbers. In contrast, CD8(+) cells in lesions from HIV(+) OPC(+) persons were in significantly higher numbers and concentrated at the lamina propria-epithelium interface, a considerable distance from the Candida at the outer epithelium. Dual fluorescence and confocal microscopy confirmed that the majority of CD8(+), but not CD4(+), cells were T cells by the presence or absence, respectively, of CD3 on each cell type. These results suggest that CD8(+) T cells may be important for oral host defense against OPC, especially when CD4 cell numbers are reduced, with a potential CD8 cell-specific dysfunction associated with susceptibility to OPC. 相似文献
5.
Vinagre C Martínez MJ Avendaño LF Landaeta M Pinto ME 《Journal of medical virology》2003,70(3):459-462
Infantile chronic recurrent parotitis (ICRP) has been attributed to multiple causes, including viral infections, and therefore its treatment remains empirical. Our aim was to evaluate the involvement of respiratory and oropharyngeal viruses in acute episodes of ICRP. Seventy children were studied, 50 patients and 20 age-matched controls, in a 2-year follow-up study. Saliva samples were taken from the parotid duct and analyzed by viral isolation and immunofluorescence for adenovirus (Ad), respiratory sincitial virus (RSV), parainfluenza virus (PI), influenza virus (Flu), Cytomegalovirus (CMV), and herpes simplex virus (HSV). Paired sera samples were tested by ELISA for anti-Epstein-Barr virus (EBV) IgG and anti-mumps IgM and IgG. Viral infections were detected in 7/50 (14%) cases of the ICRP group: one CMV; 2 Enteroviruses isolated in human embryonic lung fibroblast cells; 1 Flu A; and 3 mumps virus. No EBV seroconversions were detected. In the control group, 2 out of the 20 children had an asymptomatic mumps positive IgM titer. Our data indicate that the main respiratory and oropharyngeal viruses are not the cause of acute episodes of ICRP in Chilean children. 相似文献
6.
Phenotypic and functional properties of murine {gamma}{delta} T cell clones derived from malaria immunized, {alpha}{beta} T cell-deficient mice 总被引:1,自引:0,他引:1
Tsuji Moriya; Eyster Cassandra L.; O'Brien Rebecca L.; Born Willi K.; Bapna Mitali; Reichel Martin; Nussenzweig Ruth S.; Zavala Fidel 《International immunology》1996,8(3):359-366
Six murine T cell clones expressing TCR were generated frommalaria immunized, ß T celldeficient mice. Phenotypiccharacterization of these clones has revealed that, in contrastto conventional ß T cells, there is a considerabledegree of heterogeneity among these clones with regard to theirsurface markers and their lymphokine profile. One clone wasfound to display significant anti-parasite activity in vivoupon adoptive transfer. We attempted to determine whether theprotective clone differs in one or more key characteristicsfrom the non-protective clones. Although no obvious patternpeculiar to the protective clone was observed, it appears thatmore than one parameter may, in combination, define a distinctprotective phenotype, and thus explain the functional differencebetween the protective and non-protective clones. 相似文献
7.
Characterization of an in vitro-stimulated, Cryptococcus neoformans-specific second-order suppressor T cell and its precursor.
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Using a cryptococcal culture filtrate antigen (CneF) in a murine model, we have demonstrated previously that a cascade of Cryptococcus neoformans-specific suppressor T cells and soluble factors function in suppressing the cryptococcal delayed-type hypersensitivity (DTH) response. In addition, we have successfully hybridized the C. neoformans-specific, first-order T-suppressor (Ts1) cell and have established that the culture supernatant (hTsF1) from this hybridoma induces second-order T-suppressor (Ts2) cells in vivo. Here we report the in vitro induction of expression-phase suppressor cells. The suppressor cells were induced by culturing nylon wool-nonadherent splenic cells from naive mice with hTsF1 in the absence of CneF. Nylon wool-nonadherent splenic cells similarly cultured with supernatants from the BW5147 thymoma cells, the fusion partners of the hybridoma, did not significantly suppress the cryptococcal DTH response. The suppressor cells were designated Ts2 cells based on their similarities in function, specificity, and phenotype, i.e. L3T4-, Lyt-2+, and I-J+, to the in vivo-induced Ts2 cells. By employing the in vitro culture technique, we demonstrated that the precursors of the functional Ts2 cells were L3T4- Lyt-1-2+ I-J- cells. The induction of Ts2 cells was not associated with [3H]thymidine incorporation; therefore, we concluded that hTsF1 induces the Lyt-2+ I-J- cells to differentiate into Lyt-2+ I-J+ functional Ts2 cells without a significant amount of proliferation. From the results of this study, a better understanding of the processes involved in the regulation of the DTH response to CneF was achieved. The in vitro culture technique will allow for further detailed studies of the interactions between the various cell populations and the Ts1 cell-derived soluble factor during the induction of Ts2 cells. 相似文献
8.
In vivo depletion of CD11c+ dendritic cells abrogates priming of CD8+ T cells by exogenous cell-associated antigens 总被引:21,自引:0,他引:21
Jung S Unutmaz D Wong P Sano G De los Santos K Sparwasser T Wu S Vuthoori S Ko K Zavala F Pamer EG Littman DR Lang RA 《Immunity》2002,17(2):211-220
Cytotoxic T lymphocytes (CTL) respond to antigenic peptides presented on MHC class I molecules. On most cells, these peptides are exclusively of endogenous, cytosolic origin. Bone marrow-derived antigen-presenting cells, however, harbor a unique pathway for MHC I presentation of exogenous antigens. This mechanism permits cross-presentation of pathogen-infected cells and the priming of CTL responses against intracellular microbial infections. Here, we report a novel diphtheria toxin-based system that allows the inducible, short-term ablation of dendritic cells (DC) in vivo. We show that in vivo DC are required to cross-prime CTL precursors. Our results thus define a unique in vivo role of DC, i.e., the sensitization of the immune system for cell-associated antigens. DC-depleted mice fail to mount CTL responses to infection with the intracellular bacterium Listeria monocytogenes and the rodent malaria parasite Plasmodium yoelii. 相似文献
9.
Fidel Cano Juan A. García-Velasco Antón Millet José Remohí Carlos Simón Antonio Pellicer 《Journal of assisted reproduction and genetics》1997,14(5):254-261
Purpose: Our purpose was to assess the endocrine status of women with polycystic ovaries (PCO) undergoing IVF, and to compare oocyte
quality with endocrine markers of the syndrome, in an attempt to define a subpopulation with poor quality oocytes.
Methods: This was a retrospective study. Patients were first endocrinologically analyzed: serum levels of androgens (T, androstenedione,
DHEAS), FSH, and LH as well as glucose and insulin after an oral glucose tolerance test (OGTT) were recorded and are expressed
as absolute values and area under the curve (AUC). Subsequently, they were followed over a 2-year period in which patients
underwent several attempts of IVF as well as serving as oocyte donors. Patients were divided into three groups: group I (n=4)
was women who displayed embryos unable to implant in 15 IVF cycles and 10 ovum donation cycles in which they served as donors;
group II (n=16) was PCO patients in whom IVF (n=38) and/or oocyte donation cycles (n=42) resulted in pregnancies; and group
III (n=13) was IVF patients with normal appearance of the ovaries by ultrasound. The endocrine status was compared with the
IVF results.
Results: There was no difference among groups in the endocrinological parameters tested, except for the OGTT which identified women
in group I as having higher serum glucose and insulin levels than patients in groups II and III. Similarly, the OGTT showed
higher serum glucose values in group II compared to group III. Women in group I were also obese. Patients in group III were
older than PCO patients and needed more gonadotropins to reach an ovarian response which resulted in a reduced number of oocytes
retrieved. Fertilization was also impaired in group I, in which no pregnancy was recorded.
Conclusions: This study shows that there is a particular subgroup of PCO patients with lower fertilization rates and embryos unable to
implant. These patients are obese and nonhyperandrogenic and show derangements of insulin secretion. 相似文献
10.
The complement system plays an important role in normal human pregnancy. Uncontrolled activation of this system has been associated with many disease states. We tested the hypothesis that the C5b-9 membrane attack complex (MAC) localizes to sites of villous injury and modulates trophoblast function. Placental sections from pregnancies with no complications, intrauterine growth restriction, or preeclampsia were immunostained and the surface density for MAC and fibrin was determined by morphometric analysis. Primary cytotrophoblasts from term placentas were cultured in a FiO(2) of <1%, 8% and 20% with 10% human serum containing active MAC or heat-inactivated control serum. Immunofluorescent MAC binding to trophoblast was quantified, and the neoepitopes formed in cytokeratin 18 filaments and poly-ADP-ribose polymerase during apoptosis were used to measure cell death. Trophoblast differentiation was assessed by HCG secretion, formation of syncytia, and expression of syncytin. MAC localized to fibrin deposits in normal placentas, and especially in placentas from IUGR and preeclampsia. MAC binding to cytotrophoblasts was inversely proportional to FiO(2) and enhanced apoptosis. MAC increased markers of differentiation in cultures at 72h (medium HCG, syncytia and syncytin expression). Our findings demonstrate that MAC associates with fibrin deposits at sites of villous injury in vivo. Hypoxia also enhances MAC deposition in cultured trophoblasts and MAC alters trophoblast function in a phenotype specific manner. 相似文献