Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infection with atypical mycobacteria occurs mainly in patients with a compromised cellular immune system, in particular in those with a defective T cell or monocyte function. Here we analyzed the specific immune response of an adolescent HIV-negative patient with disseminated mycobacterium avium infection and fatal varizella zoster virus infection. The patient presented with dysplastic hematopoesis of all cell lineage's and a bicytopenia of erythrocytes and leukocytes, but a hematological malignancy could not be found. We found a peripheral lymphopenia and monocytopenia, as well as a lack of NK-cells and B-cells. Lymphocytes consisted of 95% T cells, which contained up to 40% of TCR gammadelta+CD4-CD8-T-cells (mainly TCR gamma9delta2), few monocytes and B-cells. Approximately 50% of CD3+ T-cells showed a CD57+ NK-like phenotype. Functional analysis of PBMC revealed a good antigen-specific T cell function if antigen-presenting cells were supplemented from a HLA-matched donor. Moreover, a strong M. avium specific cytotoxicity mediated by TCR alphabeta+T-cells could be found in vitro and even ex vivo. In contrast, NK-killing was absent. No evidence for a defect in IL-12 or IFN-gamma production and signaling were found. The data indicate that a strong alphabeta and gammadelta T cell immunity tries to compensate for a deficient monocyte and NK cell function in this patient.
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PMID:Strong alpha beta and gamma delta TCR response in a patient with disseminated Mycobacterium avium infection and lack of NK cells and monocytopenia. 1084 41

Although deep trichophytic infection often occurs in immunocompromised patients, the immune deficiency in such patients has not been clarified. A 28-year-old man who suffered from recalcitrant trichophytic granuloma and tinea universalis during treatment for SLE with corticosteroid is described here to define the immunological abnormalities. In addition to routine immunological tests, we evaluated the patient's innate and specific immune functions to dermatophytes, including T cell, natural killer (NK) cell and neutrophil functions and activation of the complement cascade. We measured the minimum inhibitory concentration (MIC) of itraconazole for the isolated fungus and its concentrations in the patient's serum and pus. Trichophyton (T.) rubrum was constantly isolated from the exudates of the patient's skin lesions, although the concentrations of itraconazole in his serum (198 ng/ml) and lesions (210 ng/ml) were sufficient to inhibit the growth of the isolated fungus in vitro. Specific cell-mediated immune responses, determined by T cell stimulation and IFN-gamma production, were evoked following stimulation with trichophytic antigens. The patient's innate immunity, assessed by activation of the complement cascade and neutrophil-mediated phagocytosis, was not impaired. The number of circulating NK cells was markedly decreased (0.2% of the peripheral blood mononuclear cells), and was associated with low NK cell activity against K-562 cells even though lymphopenia had improved. The deficiency of innate immunity mediated by NK cells might be responsible for a part of the persistence of trichophytic granuloma in our case. Dermatophytes usually affect the horny layer of the skin and do not invade the living layers because the host immune system uses various mechanisms to eliminate the fungi. Both specific T cell-mediated immunity and nonspecific immunological mechanisms provide host defense against fungal infections. An adaptive immune response is usually preceded by innate immune responses mediated by neutrophils, NK cells, and circulating proteins such as complement components and anti-microbial peptides. However, in patients with localized or systemic immunological defects, granulomatous cutaneous infection of dermatophytes mostly caused by trichophytic fungi may occur [1]. Trichophytic granuloma includes Majocchi's granuloma [2] and disseminated trichophytic granuloma [3]. Recently, we experienced a patient with trichophytic granuloma and tinea universalis caused by Trichophyton (T.) rubrum infection during treatment with corticosteroid for systemic lupus erythematosus (SLE). We describe the clinical details of this patient, focusing on his immunological defects which led to the persistence of the fungal infection.
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PMID:Recalcitrant trichophytic granuloma associated with NK-cell deficiency in a SLE patient treated with corticosteroid. 1117 42

A major hurdle to lipoplex-based systemic gene delivery is acute inflammatory toxicity. In this study, a safe, simple, and effective alternative to lipoplex administration, specifically, sequential injection of cationic liposome and plasmid DNA, was evaluated. When plasmid DNA was injected into the tail vein of mice 2-5 min after the injection of cationic liposomes, 50-80% lower levels of proinflammatory cytokines, including TNF-alpha, IL-12, and IFN-gamma, were observed compared to lipoplex injection. The sequential injection technique yielded a two- to fivefold higher level of transgene expression in the lung and was more effective in repeated dosing than lipoplex. Other types of lipoplex-associated toxicities, such as neutropenia, lymphopenia, thrombocytopenia, and complement depletion, were also significantly reduced with sequential injection. The reduction in cytokine release was observed with several different liposome formulations and appeared to be a general phenomenon.
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PMID:Sequential injection of cationic liposome and plasmid DNA effectively transfects the lung with minimal inflammatory toxicity. 1135 72

A number of experimental models of organ-specific autoimmunity involve a period of peripheral T cell lymphopenia prior to disease onset. In particular, experimental autoimmune gastritis, induced in susceptible mouse strains by neonatal thymectomy, is a CD4+ T cell mediated autoimmune disease. We have previously demonstrated that this disease displays the hallmarks of a Th1-mediated DTH inflammatory response with an essential role for IFN-gamma very early in the pathogenesis of disease. Given the interplay between the innate and adaptive immune responses, a potential source of early IFN-gamma production in these lymphopenic mice is the innate immune response. Here we have assessed the contribution of innate immunity to the induction of experimental autoimmune gastritis, in particular, the role of natural killer (NK) cells in production of IFN-gamma. Analysis of NK cells and macrophages revealed no difference in either the number or activation status between euthymic and neonatally thymectomised mice. Furthermore, in vivo depletion of NK cells immediately after neonatal thymectomy of (BALB/cCrSlcxC57BL/6) F1 mice demonstrated no reduction in disease incidence compared to control groups of neonatally thymectomised mice. Therefore, we conclude that NK cells are not the primary source of IFN-gamma required for the pathogenesis of autoimmune gastritis following neonatal thymectomy but rather the small cohort of T cells in the periphery of lymphopenic mice are likely to be responsible for the IFN-gamma production.
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PMID:The role of natural killer cells in the induction of autoimmune gastritis. 1190 44

Fifty subjects living in a malaria endemic area were studied at diagnosis of a Plasmodium falciparum attack and 3 weeks later. Absolute numbers of CD3(+), CD4(+) and CD8(+) lymphocytes as well as plasma cytokines and secreted cytokines after in vitro mitogenic stimulation were measured. At enrollment, lymphopenia was observed, lending support to the reallocation hypothesis during the acute phase. A significant elevation of the number of CD8(+) cells was present in the peripheral blood during the recovery phase. During the acute phase, plasma IL-6 levels peaked while in vitro production capacity was high at both phases. Plasma IL-6 concentrations were positively related to blood parasite density at D0, as IL-4 and IFN-gamma, suggesting an early intervention of these cytokines. Plasma IL-2 levels were low at diagnosis although cells retained their ability to produce IL-2, which was found more frequently in plasma after cure. Acquisition of immunity with age was in relation with greater secretion abilities of cells for type 1 and type 2 cytokines during the parasite clearance phase. We conclude to an early implication of type 2 cytokines and IFN-gamma, with particularly high levels of IL-6.
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PMID:Plasma and in vitro levels of cytokines during and after a Plasmodium falciparum malaria attack in Gabon. 1220 92

The thymus is the unique lymphoid organ inside which a confrontation occurs throughout life between neuroendocrine self-antigens and a recently evolved system with original recombination machinery driving random generation of immune response diversity. Through transcription of neuroendocrine genes in the thymus stromal network and expression of cognate receptors by immature T cells, the neuroendocrine system regulates early T cell differentiation. In addition and more specifically, intrathymic presentation of neuroendocrine self-antigens by, or in close association with, major histocompatibility complex (MHC) proteins is responsible for the establishment of central immune self-tolerance of neuroendocrine principles. All members of the insulin gene (INS) family are expressed in the thymus stroma according to a precise hierarchy and cell topography: IGF2 (thymic epithelial cells) > IGF1 (thymic macrophages) >> INS (thymic medullary epithelial cells and/or dendritic cells). Given this hierarchical pattern in gene expression, the protein IGF-2 is more tolerated than INS. Igf2 transcription is defective in the thymus of bio-breeding (BB) rat, one animal model of type 1 diabetes (T1DM). This thymus-specific defect in Igf2 expression may explain both the absence of central tolerance to INS-secreting beta cells and the lymphopenia (including lack of regulatory RT6(+) T cells) in diabetes-prone BB rats. INS B:9-23 and the homologous sequence of IGF-2 compete for binding to DQ8, an MHC class II allele conferring major susceptibility to T1DM. In young DQ8(+) T1DM patients, INS B:9-23 presentation by DQ8 elicits a dominant IFN-gamma secretion by isolated PBMCs, whereas presentation of the IGF-2 self-antigen promotes a dominant regulatory interleukin-10 secretion. These data demonstrate that opposite immune responses are driven by MHC presentation of a self-antigen (here, IGF-2) and an autoantigen (INS, as "altered" self). The important tolerogenic properties of thymic self-antigens deserve now to be exploited for prevention and/or cure of devastating autoimmune diseases such as T1DM.
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PMID:Role of the thymus in the development of tolerance and autoimmunity towards the neuroendocrine system. 1279 58

Fifteen 8-week-old conventional pigs were selected from a farm where pigs were suffering from postweaning multisystemic wasting syndrome (PMWS). Ten of the animals were diseased pigs showing typical signs of PMWS (wasting and respiratory disorders) and positive for infection with porcine circovirus type 2 (PCV2), and the other five animals selected as controls were pen-mate, apparently healthy pigs. Blood samples and lymphoid tissues were taken from each animal for haematological, serological and histopathological studies. Also, cytokine mRNA expression of IL-1beta, IL-2, IL-4, IL-8, IL-10, IL-12p40 and IFN-gamma from inguinal and bronchial lymph nodes, tonsils, spleen and thymus was determined by semi-quantitative RT-PCR. Pigs suffering from PMWS showed severe alterations of haematological parameters such as anaemia, lymphopenia with decrease of CD8(+) and IgM(+) cells, monocytosis and neutrophilia. Also, extensive lymphocyte depletion and altered cytokine mRNA expression patterns were seen in most of the examined lymphoid organs. Those cytokine mRNA alterations were characterized by an overexpression of IL-10 mRNA in thymus and IFN-gamma mRNA in tonsils, and by decreases in the mRNA expression of several cytokines as IL-2 and IL-12p40 in the spleen, IL-4 in tonsils, and IFN-gamma, IL-10, IL-12p40 and IL-4 in inguinal lymph nodes. Also, the IL-10 mRNA overexpression was histologically associated with the thymic depletion and atrophy observed in PMWS pigs. In conclusion, the cytokine mRNA imbalance, specially the increased mRNA levels of IL-10 in the thymus, jointly with the histopathological and haematological disorders, are highly indicative of a T-cell immunosuppression, enhancing the notion that the immune system of PMWS-affected pigs is severely impaired.
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PMID:Cytokine mRNA expression profiles in lymphoid tissues of pigs naturally affected by postweaning multisystemic wasting syndrome. 1286 43

The aim of this study was to evaluate the tolerability of intratumoral administered recombinant human interleukin-12 (rhIL-12) in patients with head and neck squamous cell carcinoma. Six patients were treated once a week at two dose levels of 100 or 300 ng/kg, respectively, up to 24 weeks. The primary end point was to assess the toxicity and safety of intratumoral injected rhIL-12 in head and neck squamous cell carcinoma patients; the pharmacokinetics and pharmacodynamics of rhIL-12 and any evidence of antitumor effect were also determined. Toxicity was mild, with prolonged grade 4 lymphopenia observed in only one patient. No dose-limiting toxicities occurred. In all six patients, the rhIL-12 was detectable in plasma within 30 min. Significant reductions in absolute number of peripheral blood lymphocytes and all lymphocyte subsets, especially cytotoxic T cells and natural killer cells, were observed that were maximal between 12 and 24 h. Maximal plasma concentrations of IFN-gamma and IL-10 were detected after 12 h. A real-time semiquantitative PCR analysis in peripheral blood mononuclear cells showed a mean increase of mRNA encoding IFN-gamma of 2.2 times relative to the pretreatment sample. An unexpected, significant decrease of 80% in T-bet mRNA, a T-helper 1 transcription factor, was detected after 12 h, with normalization after 48-72 h. No complete or partial responses were observed. In one patient, a 40% regression of a tumor lesion was noted. In conclusion, rhIL-12 at these dose levels and schedule was well tolerated and resulted in measurable immunological responses.
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PMID:Pharmacokinetics and immunological aspects of a phase Ib study with intratumoral administration of recombinant human interleukin-12 in patients with head and neck squamous cell carcinoma: a decrease of T-bet in peripheral blood mononuclear cells. 1291 41

Healthy, nonimmunized C57BL/6 (B6) mice contain memory phenotype CD8+ T cells, which are assumed to be generated in response to environmental Ags. Since neonatal mice are functionally lymphopenic within the first days after birth, we investigated the alternative possibility that the memory CD8+ T cells of untreated B6 mice are the result of lymphopenia-induced proliferation during neonatal life. We show here that adoptively transferred CD8+ T cells proliferate in neonatal B6 mice, rapidly produce IFN-gamma, and develop into memory cells which are maintained until adulthood. In contrast to CD4+ T cells, neonatal lymphopenia-induced proliferation of CD8+ T cells was IL-7 dependent. Thus, neonatal lymphopenia seems to allow CD8+ thymic emigrants to undergo lymphopenia-induced proliferation during early neonatal life to equip the immune system with a set of preactivated CD8+ T cells before any infection, which might contribute to the rapid initiation of immune responses in the adult.
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PMID:Cutting edge: IL-7-dependent homeostatic proliferation of CD8+ T cells in neonatal mice allows the generation of long-lived natural memory T cells. 1468 3

Although IFN-gamma is essential for host control of mycobacterial infection, the mechanisms by which the cytokine restricts pathogen growth are only partially understood. LRG-47 is an IFN-inducible GTP-binding protein previously shown to be required for IFN-gamma-dependent host resistance to acute Listeria monocytogenes and Toxoplasma gondii infections. To examine the role of LRG-47 in control of mycobacterial infection, LRG-47(-/-) and wild-type mice were infected with Mycobacterium avium, and host responses were analyzed. LRG-47 protein was strongly induced in livers of infected wild-type animals in an IFN-gamma-dependent manner. LRG-47(-/-) mice were unable to control bacterial replication, but survived the acute phase, succumbing 11-16 wk postinfection. IFN-gamma-primed, bone marrow-derived macrophages from LRG-47(-/-) and wild-type animals produced equivalent levels of TNF and NO upon M. avium infection in vitro and developed similar intracellular bacterial loads. In addition, priming for IFN-gamma production was observed in T cells isolated from infected LRG-47(-/-) mice. Importantly, however, mycobacterial granulomas in LRG-47(-/-) mice showed a marked lymphocyte deficiency. Further examination of these animals revealed a profound systemic lymphopenia and anemia triggered by infection. As LRG47(-/-) T lymphocytes were found to both survive and confer resistance to M. avium in recipient recombinase-activating gene-2(-/-) mice, the defect in cellular response and bacterial control in LRG-47(-/-) mice may also depend on a factor(s) expressed in a nonlymphocyte compartment. These findings establish a role for LRG-47 in host control of mycobacteria and demonstrate that in the context of the IFN-gamma response to persistent infection, LRG-47 can have downstream regulatory effects on lymphocyte survival.
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PMID:Mice deficient in LRG-47 display increased susceptibility to mycobacterial infection associated with the induction of lymphopenia. 1470 92


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