Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009450 (infectious diseases)
 83,438 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Distinct patterns of T cell cytokine production have been shown to influence the outcome of infection in mouse models and humans. Th1 or Type 1 cytokines, interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) are generally associated with resistance to infection, whereas Th2 or Type 2 cytokines, IL-4 and IL-10 are associated with progressive disease. Leprosy is a useful model for studying the role of cytokines in modulating T cell responses in human infectious disease. Infection by Mycobacterium leprae results in disease manifestations that encompass an immunological spectrum. Tuberculoid patients are able to restrict the growth of the pathogen and mount strong T cell responses to M. leprae. In contrast, lepromatous patients manifest disseminated infection and their T cells weakly respond to M. leprae. We have found that tuberculoid leprosy lesions have a predominance of CD4+ T cells producing the Type 1 cytokine pattern. Secondly, IL-12 mRNA was expressed at 10-fold higher levels in tuberculoid lesions as compared to lepromatous lesions and that IL-12 promotes the selective expansion of the Type 1 cytokine producing cells. In contrast, lepromatous lesions contain CD8+ IL-4-producing cells that suppress antigen-specific T cell responses and promote the outgrowth of additional suppressor T cells. IL-10, also expressed at higher levels in lepromatous as compared to tuberculoid lesions, was found to be produced by macrophages, effectively inhibiting cytokine production and macrophage activity.
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PMID:Cytokine patterns at the site of mycobacterial infection. 771 51

Infection of mice with the protozoan parasite Leishmania major is an established model with which to study the in vivo development of CD4+ Th cell subsets. Interferon-gamma (IFN-gamma), produced by natural killer (NK) cells (AsGM1+, CD4-, CD8-, CD3-), regulates CD4+ T cell subset development and early resistance to L. major. Rapid Th1 cell development and resistance to infection occur in mice that develop an NK cell response early after infection (C3H and immunized BALB/c mice), whereas mice that lack an early NK cell response demonstrate delayed Th1 cell development and enhanced early disease (C57BL/6) or lack detectable Th1 cell development altogether and develop a progressive, fatal infection (BALB/c). Analysis of the requirements for NK cell activation in C3H mice revealed that the NK cell response is both interleukin-2 (IL-2) and IL-12 dependent. Although delayed IL-12 production in C57BL/6 mice precludes NK cell activation, the eventual development of a Th1 response appears to be IL-12 dependent. In contrast, concomitant production of inhibitory factors (IL-4, IL-10, and transforming growth factor beta) with IL-12 and IL-2 prevents NK cell activation in BALB/c mice. Together, these observations support a paradigm of in vivo Th1 cell development that involves IL-12-dependent stimulation of IFN-gamma production by NK cells.
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PMID:The role of the innate immune response in Th1 cell development following Leishmania major infection. 772 8

Data from animal models indicate that interleukin-2 is potentially valuable in the treatment of a variety of infectious diseases of viral, fungal, protozoal, bacterial, and mycobacterial origin. The role of interleukin-2 in resistance to infection with human immunodeficiency virus or Mycobacterium leprae (the causative agent of leprosy) has recently been studied in detail. Data from animal models and clinical trials indicate that relatively low doses of interleukin-2 effectively stabilize or reverse the course of these infections. The recent characterization of Th1 and Th2 helper T cells, and their relationship to the control of infectious diseases, are revealing the mechanisms involved in producing disease. Increased understanding of these mechanisms may help extend interleukin-2 therapy to other clinical applications.
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PMID:The use of recombinant human interleukin-2 in treating infectious diseases. 776 71

Interleukin-2 (IL-2) is an immunoregulatory cytokine whose biological effects are mediated through interaction with specific receptors on the surface of target cells. Due to its presumed role in generating a normal immune response, IL-2 is being evaluated for the treatment of a variety of tumors, in addition to infectious diseases. During the study of the structure-activity relationships for IL-2 and its receptors, one analog in which threonines at positions 41 and 51 were replaced by prolines (T41/51P) was found to possess apparent signaling abnormalities. Bioassays and receptor binding assays with human peripheral blood lymphocytes revealed the EC50 and Kd values of this analog to be 200 pM and 5.9 nM, respectively. Although the EC50 is greater and the receptor affinity of T41/51P is much weaker than that of wild-type IL-2, receptor occupancy versus biological response comparisons indicated that a much lower receptor occupancy was required to generate an equivalent biological response. Competitive receptor binding analyses with both intermediate affinity (beta/gamma subunit complex) and low affinity (alpha subunit) receptors were carried out to assess the origin of this phenomenon. Similar analyses of the singly substituted T41P and T51P analogs were carried out. From these studies, it was apparent that facilitated signaling was mainly attributable to position 51, whereas mutations at position 41 primarily influenced low affinity binding. The observation that the T51P analog facilitates response, compared with wild-type IL-2, may indicate a signaling-dependent conformational change in IL-2 upon receptor binding.
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PMID:Structural analogs of interleukin-2: a point mutation that facilitates biological response. 783 30

This study was designed to investigate serum soluble interleukin-2 receptor (S-IL-2R), interleukin-2 (IL-2) and interleukin-6 levels (IL-6) in patients with either a positive or negative Borrelia burgdorferi serology. Serum samples from 101 individuals, divided in to five groups according to clinical symptoms and outcome of serology were analysed. Samples of cerebrospinal fluid (CSF) from nine of the individuals were also studied. The highest average serum S-IL-2R levels (1,180 +/- 1,140 U/ml) were found in patients with erythema migrans, the hallmark of Lyme borreliosis, followed by patients with symptoms closely related to Borrelia infection (900 +/- 1,200 U/ml) and with a strong positive serology. In two patients with central nervous system (CNS) involvement, increased levels of S-IL-2R of 920 and 620 U/ml respectively (normal value < 50 U/ml) were detected in the CSF. No statistically significant relationship between IgG or IgM antibody activity and serum S-IL-2R levels was found. Detectable levels of IL-2 were only found in three patients. Increased levels of IL-6 were found in sera from 14 patients. The highest concentration, 90 pg/ml (normal value < 10 pg/ml), was measured in a patient presenting with vasculitis. In conclusion, B. burgdorferi infection causes a moderate increase of serum S-IL-2R levels, although there is no relationship between the severity of the infection, as estimated by the antibody concentration or to serum IL-2 or IL-6 levels. Secondary complications of the infection, such as vasculitis, may cause an increased level of serum IL-6.(ABSTRACT TRUNCATED AT 250 WORDS)
Infection
PMID:Response of soluble IL-2 receptor, interleukin-2 and interleukin-6 in patients with positive and negative Borrelia burgdorferi serology. 784 8

Infection of mice with murine cytomegalovirus (CMV) presents a model for the study of the role of the immune system in the pathogenesis of human CMV. The contribution of the different spleen cell subsets in conferring curative immunocytotherapy to fatally MCMV-infected immunosuppressed mice was assessed using adoptive immunotherapy. It was found that the efficacy of passively transferred immune spleen cells is dose dependent and that the therapeutic effect can be enhanced considerably by treating donor mice with thymic humoral factor (THF-gamma 2). Polymerase chain reaction (PCR) of the donor spleen population was negative, indicating that no MCMV-DNA was transferred with the immune cells. Analysis of the donor mice after THF-gamma 2 treatment showed increased levels of CMV-neutralizing antibodies, while enhancement of natural killer (NK) activity was transient and lasted only during the early phase of the infection. FACS analysis demonstrated that treatment with THF-gamma 2 restored the size of both cell subsets CD4+ and CD8+ that were decreased following MCMV infection. It is shown that both CD4+ and CD8+ T-cell subsets participate in controlling the development of the fatal disease in MCMV-infected immunosuppressed recipients. It is suggested that the enhancement of the immunocompetence of both populations of spleen cells from treated donors is mediated in part by the restoration of Interleukin-2 (IL-2) production by THF-gamma 2.
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PMID:Thymic humoral factor, THF-gamma 2, enhances immunotherapy of murine cytomegalovirus (MCMV) infection by both CD4+ and CD8+ immune T cells. 790 78

Interleukin-2 (IL-2) is a hormone of the immune system responsible for control of the proliferation and cytotoxicity of T lymphocytes and natural killer cells as well as the proliferation of B lymphocytes. Recombinant IL-2 has been only minimally to modestly successfully to date in the treatment of cancer and infectious diseases, largely because the drug is associated with toxicity and a narrow therapeutic index. Quantitative measurement of IL-2 can be quickly done by enzyme immunoassay. IL-2 bioassay provides an index of biologically active cytokine. IL-2 action and pharmacokinetics can be understood in the context of the effect IL-2 on high (alpha, beta, gamma trimer) vs intermediate (alpha, beta) vs low (beta only or alpha only) affinity IL-2 receptors on various cells of the immune system. IL-2 undergoes rapid renal elimination. The route of administration is important to determine the provision of sustained drug concentrations adequate to support the proliferation and cytotoxicity of immune cells. When IL-2 is given intravenously it has rapid elimination pharmacokinetics with an initial elimination half-life and terminal elimination half-life (t1/2 beta) of 6 to 12 minutes and 40 to 80 minutes, respectively. Subcutaneous or intramuscular administration of IL-2 results in sustained systemic absorption and approximately 30% of the injected dose is absorbed. Because IL-2 is less rapidly cleared from the site of intracavitary injection, when the drug is given by these less traditional routes (e.g. intraperitoneal, intrapleural, intrathecal, intraventricular, intravesicular, and inhalational administration) sustained local IL-2 activity can result. In some cases this has resulted in an improved therapeutic index compared with that resulting after administration of the drug by high dose intravenous bolus or continuous infusion. Depot IL-2 preparations may offer more convenient administration (e.g. t1/2 beta of polyethylene glycolated IL-2 is approximately 10-fold higher than that of recombinant IL-2) or more favourable biodistribution (e.g. IL-2 liposomes are more potent against lung metastases) compared with IL-2 administered by more conventional routes. An understanding of IL-2 clinical pharmacokinetics in relation to immunobiology of this central cytokine should lead to less toxicity and more effective clinical use.
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PMID:Effects of route and formulation on clinical pharmacokinetics of interleukin-2. 795 69

A drug delivery system (DDS) for the treatment of infectious disease has recently been developed. Since liposomal antimicrobial agents are effective on cytozoic bacteria, we applied liposomal streptomycin and amikacin for the treatment of systemic mycobacterial tuberculosis in mice. Liposomal aminoglycosides showed excellent efficacy compared to free aminoglycosides or empty liposome. This therapeutic strategy should be developed for clinical application. Although the human defense mechanism against microbial infection is very complicated, biological response modifiers (BRM) such as vaccination or cytokine therapy have been investigated. One of the most useful and protective vaccines for prevention of tuberculosis is the Mycobacterium vaccae vaccine, developed by Stanford et al. As for the cytokines, interleukin-2, granulocyte macrophage-colony stimulating factor, and tumor necrosis factor have very strong antimycobacterial activity. Interferon alone, however, has weak efficacy, and should be combined with other effective cytokines. These BRM constitute an excellent strategy for antimycobacterial chemotherapy.
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PMID:[A drug delivery system and biological response modifiers for the treatment of mycobacterial infection]. 812 87

A variety of cytokines secreted by cells of the immune system could contribute to the induction or persistence of the inflammatory processes in autoimmune and infectious diseases. Soluble CD23 (sCD23) and interleukin-4 (IL-4) are the recently characterized factors implicated in B cell-T cell function in human disease. In this study we examined the circulating levels of sCD23, IL-4, and soluble interleukin-2 receptors (sIL-2R) from patients with hepatitis B surface antigen-positive (HBsAg+) acute viral hepatitis (AVH), HBsAg+ chronic active hepatitis (HBsAg+ CAH), and autoimmune chronic active hepatitis (AICAH) and from autoimmune rheumatic disease patients, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). The sCD23 was found in sera from 16 of 16 patients with AICAH (159.0 +/- 40.8 ng/ml), in 3 of 32 patients with AVH (4.1 +/- 15.6), 5 of 30 patients with HBsAg+ CAH (6.9 +/- 17), 8 of 25 patients with SLE (19.4 +/- 37.2), 2 of 21 patients with RA (4.7 +/- 16.3), and none of the 50 age-matched healthy controls. However, sIL-2R was detected more frequently in sera from all hepatitis and rheumatic disease patients. In AICAH, sCD23 levels correlated positively with IL-4 (r = 0.44, P = 0.001) but not with sIL-2R. Markedly elevated levels of sCD23 and IL-4 in serum are prominent and characteristic features of AICAH disease, which could play an important role in the pathogenesis or induction and perpetuation of the inflammatory response in this disorder.
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PMID:Soluble CD23 and interleukin-4 levels in autoimmune chronic active hepatitis and systemic lupus erythematosus. 813 57

Patients rendered T cell-deficient by advanced disease due to human immunodeficiency virus, an underlying neoplastic disorder, or immunosuppressive therapy are vulnerable to a select group of opportunistic infections. These infections, which often fail to respond to conventional therapy, provide the clinical setting in which the efficacy of treatment with cytokines can be tested. Particularly pertinent cytokines are those that activate macrophages and monocytes or enhance T-cell function. Experimental observations and emerging data from patients with intact T-cell function suggest that treatment with at least three cytokines, interferon-gamma, interleukin-2, and granulocyte-macrophage colony-stimulating factor (GM-CSF) may be of benefit. Each of these cytokines is already in clinical use, and each has therapeutic potential in a variety of different infectious disease. Patients with infections caused by opportunistic intracellular pathogens appear to be the most appropriate candidates for adjunctive cytokine therapy.
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PMID:Cytokines as antimicrobial therapy for the T cell-deficient patient: prospects for treatment of nonviral opportunistic infections. 827 6


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