Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0021051 (immunodeficiency)
71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A variant simian immunodeficiency virus (SIV) from sooty mangabeys, SIVsmmPBj, induces an acutely lethal disease in pigtailed macaques (Macaca nemestrina). This study further characterizes the viral genetic determinants involved in this acutely lethal disease. We have generated chimeric molecular clones constructed between SIVsmmPBj and either SIVsmH4 or SIVsmm9 to analyze the role of the 5' half of the genome and the envelope gene in the induction of acute disease. These studies suggest that the gag and gp40 of SIVsmmPBj are required for the development of lethal disease, and an additional determinant in the central regulatory gene region of the SIVsmmPBj genome is also required.
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PMID:Viral genetic determinants in SIVsmmPBj pathogenesis. 796 28

Infection with a variant of simian immunodeficiency virus, SIVsmmPBj14, leads to severe acute disease in macaques. This study was designed to investigate the functional significance of previously described mutations in the viral long terminal repeat (LTR) and to elucidate their contribution to the unique phenotype of SIVsmmPBj14. LTR-directed transcription was measured by using luciferase reporter constructs that were transiently transfected into cultured cells. In a wide range of cell types, the basal transcriptional activity of the LTR from SIVsmmPBj14 was found to be 2- to 4.5-fold higher than that of an LTR from a non-acutely pathogenic strain. These LTRs differ by five point mutations and a 22-bp duplication in SIVsmmPBj14, which includes a nuclear factor kappa B (NF kappa B) site. Transcriptional differences between these LTRs were further enhanced by two- to threefold upon treatment of cells with phorbol ester or tumor necrosis factor alpha or by cotransfection with plasmids expressing NF kappa B subunits. Mutagenesis studies, and the use of a reporter construct containing an enhancerless promoter, indicate that these transcriptional effects are due principally to the 22-bp sequence duplication and the NF kappa B site contained within it. Finally, infectious virus stocks that were isogenic except for the LTR were generated. The LTR from SIVsmmPBj14 was found to confer an increase in the kinetics of virus replication in cultured cells. Inclusion of this LTR in recombinant SIVs also resulted in a two- to threefold rise in the extent of cellular proliferation that was induced in quiescent simian peripheral blood mononuclear cells. These studies are consistent with the hypothesis that LTR mutations assist SIVsmmPBj14 in responding efficiently to cellular stimulation and allow it to replicate to high titers during the acute phase of viral infection.
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PMID:Enhanced responsiveness to nuclear factor kappa B contributes to the unique phenotype of simian immunodeficiency virus variant SIVsmmPBj14. 796 69

The simian immunodeficiency virus SIVsmmPBj14 (SIV-PBj14) is an atypical lentivirus that causes acute disease and death in pig-tailed macaques and in vitro replicates efficiently in resting macaque lymphocytes and activates and induces proliferation of lymphocytes. The present study was conducted to test the hypothesis that production of large quantities of SIV-PBj14 induces widespread immune activation and elaboration of cytokines which lead directly to the death of infected pig-tailed macaques. Following intravenous inoculation of pig-tailed macaques with SIV-PBj14, acute disease developed and was characterized by high levels of plasma viremia, p27gag antigenemia, tumor necrosis factor alpha, and interleukin-6 (IL-6). All animals died within 10 days of infection, at which time some animals had as many as 100% CD4+ cells in the periphery and lymphoid tissues infected. During the last few days before death, titers of infectious virus in blood increased as much as 10(5)-fold. By using dual-label immunofluorescence assays for detection of cell surface activation markers, both CD4+ and CD8+ lymphocytes were shown to express the IL-2 and transferrin receptors following either in vivo or in vitro infection with SIV-PBj14. Furthermore, in vitro infection of quiescent macaque lymphocytes by SIV-PBj14 was accompanied by proliferation of both CD4+ and CD8+ lymphocyte subsets, as measured by incorporation of [3H]thymidine. Increases in numbers of activated lymphocytes and levels of proinflammatory cytokines in plasma coincided with increased amounts of detectable virus in vivo. Clinical signs of disease and pathologic findings were most consistent with death from a shock-like syndrome, in which acute-phase inflammatory cytokines are known to play a major role. Tumor necrosis factor alpha, IL-2, and IL-6 were detected in some cultures infected with SIV-PBj14, but this finding was not consistent. When cytokines were detected, their concentrations were essentially no different from those found in control cultures infected with SIVsmm9, a prototypic strain from which SIV-PBj14 was derived. The in vivo results suggest a synergistic cycle of activation of lymphocytes and monocytes, elaboration of cytokines, and virus production that accelerates uncontrolled and culminates in death. The observed correlations between in vivo and in vitro activation events following SIV-PBj14 infection validate the use of in vitro studies to clarify lentivirus-lymphocyte interactions that may contribute to the virulence of SIV-PBj14.
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PMID:Immune activation and viral burden in acute disease induced by simian immunodeficiency virus SIVsmmPBj14: correlation between in vitro and in vivo events. 805 36

In 48 patients with a history of a pneumococcal bacteremia, serum taken during the acute phase of the infection was analyzed for IgG and IgG subclasses. Once the patients were free of infection, a serum sample was analyzed for IgG, IgG subclasses, IgA and IgM. In an additional 20 patients, it was only possible to analyze serum from the infection-free phase. Seventeen of 48 (35%) patients had reduced levels of total IgG or of one or more of the IgG subclasses during acute disease. Of the 48 patients in whom both acute phase and infection-free phase serum were analyzed, values of IgG (p < 0.001), IgG1 (p < 0.001), IgG2 (p < 0.001), IgG3 (p < 0.01) and IgG4 (p < 0.01) were decreased during the acute infection. During the infection-free phase, 12 of 68 (18%) patients had a recognizable immunodeficiency, including two patients with common variable immunodeficiency. Routine screening for immunoglobulins during the infection-free period could result in the discovery of previously unrecognized immunoglobulin deficiencies in patients with a history of bacteremic pneumococcal infection.
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PMID:Analysis of immunoglobulin isotype levels in acute pneumococcal bacteremia and in convalescence. 807 Apr 49

Simian immunodeficiency virus (SIV) induces an immunodeficiency syndrome similar to human AIDS. Although the disease course of SIV-induced immunodeficiency is generally measured in months to years, a disease syndrome that results in death in 5 to 14 days has been described in pig-tailed macaques infected with the SIVsmmPBj (PBj) strain. The purpose of this study was to derive an acutely lethal PBj molecular clone in order to study viral genes involved in pathogenesis. Six infectious molecular clones were generated; acutely fatal disease was induced by experimental inoculation of pig-tailed macaques with virus stocks derived from either of two clones, PBj6.6 or PBj14.6. Molecular chimeras were constructed by exchange of regions of the genome of PBj6.6 and a nonlethal, related clone, SIVsmH4. Only a chimera expressing the PBj genome under the control of a SIVsmH4 long terminal repeat induced death soon after inoculation. These studies suggest that multiple viral genes of PBj are critical for development of acute disease. More specifically, the env gene but not the long terminal repeat PBj was required for acute disease induction; however env must act in concert with another gene(s) of the PBj genome.
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PMID:Multiple viral determinants contribute to pathogenicity of the acutely lethal simian immunodeficiency virus SIVsmmPBj variant. 847 53

Cryptococcosis is a major cause of illness and death among persons infected with human immunodeficiency virus (HIV). Its management must include both initial and maintenance treatment. Although most authorities favor an initial period of therapy with amphotericin B for acute cryptococcosis, the triazoles play a role in both the management of acute disease and subsequent maintenance therapy. AIDS surveillance data collected by the Centers for Disease Control and Prevention document the occurrence of cryptococcosis in more than 17,000 (6.2%) of adults with AIDS in the United States, although this figure is known to be an underestimate. The risk of cryptococcosis among HIV-infected persons is highest at CD4+ lymphocyte counts of < 100/microL. Although cryptococcosis is especially frequent among AIDS patients who are black, male, or injection drug users, the explanations for these patterns remain unclear. Whether geographic differences in rates of cryptococcosis result from variations in the environmental distribution of Cryptococcus neoformans as well as in the distribution of HIV infection is also unclear. Although exposure to pigeon feces is the best known of the putative exposure-related risk factors, proof is lacking that avian excreta are the primary environmental source of the organism in most cases of cryptococcosis. Prophylaxis with triazoles can prevent cryptococcosis and may be considered for adults and adolescents with CD4+ counts of < 50/microL. However, it is uncertain whether prophylaxis will affect survival, be cost-effective, or have an adverse impact on the susceptibility of a variety of fungi to antifungal drugs. Vaccines and monoclonal antibodies designed to prevent or modify cryptococcosis in HIV-infected persons are in the experimental stage.
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PMID:Prospects for preventing cryptococcosis in persons infected with human immunodeficiency virus. 854 96

Coccidioidomycosis is an uncommon AIDS-defining illness that is endemic in the southwestern United States. In profoundly immunodeficient patients infected with human immunodeficiency virus (HIV), the disease is usually manifest as severe pulmonary infection and is associated with high mortality. Although diagnosis is often made by routine serological tests, these appear to be less sensitive than when used for patients who are not HIV-infected. New ways to diagnose the infection in HIV-infected patients earlier and with more certainty are urgently needed. The optimal antifungal regimen for active disease in HIV-infected patients is currently undefined, but following acute disease in severely immunocompromised HIV-infected patients (CD4 lymphocyte count, < 200/microL), lifelong systemic antifungal therapy is recommended. The role of chemoprophylaxis for HIV-infected patients in the area of endemic disease is also unclear. Improvement of preventive strategies must await the results of well-designed future studies to determine risk factors, particularly environmental factors, for development of coccidioidomycosis and to determine the proportion of disease due to new vs. reactivated infection. These studies are also needed to elucidate the role and efficacy of different types of antifungal drug therapies and the specific dosages useful for prevention, treatment, and long-term control of these infections.
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PMID:Opportunistic coccidioidomycosis in patients infected with human immunodeficiency virus: prevention issues and priorities. 854 98

Mucosal candidiasis (oropharyngeal, esophageal, and vulvovaginal candidiasis) has been among the most prominent opportunistic infections in persons infected with human immunodeficiency virus (HIV). Esophageal candidiasis, an AIDS-defining illness, accounted for 15% of the AIDS-defining illnesses in adults and adolescents diagnosed in the United States through 1992. The diagnosis of oropharyngeal and vaginal candidiasis is based on clinically consistent signs and symptoms and a positive culture or a positive gram, KOH, or calcofluor stain, whereas the diagnosis of esophageal and pulmonary candidiasis is based on histopathology. Although a prospective controlled trial showed that prophylaxis with fluconazole can reduce the risk of mucosal candidiasis in patients with advanced HIV disease, routine primary prophylaxis is not recommended because of the effectiveness of therapy for acute disease, the low mortality associated with mucosal candidiasis, the potential for development of drug-resistant candidal infection, and the cost of prophylaxis. The probability of recurrences increases as CD4 counts decline. Nonetheless, many experts do not recommend chronic prophylaxis to prevent recurrent oropharyngeal and vulvovaginal candidiasis, for the same reasons that primary prophylaxis is not recommended. However, if recurrences are frequent or severe following documented esophageal candidiasis, long-term suppressive therapy with fluconazole should be considered.
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PMID:Opportunistic candidal infections in patients infected with human immunodeficiency virus: prevention issues and priorities. 854 20

When residues 17 and 18 in nef of simian immunodeficiency virus strain SIVmac239 were changed from RQ to YE, the resultant virus was able to replicate in peripheral blood mononuclear cell cultures without prior lymphocyte activation and without the addition of exogenous interleukin-2, caused extensive lymphocyte activation in these cultures, and produced an acute disease in rhesus and pigtail macaques (Z. Du, S. M. Lang, V. G. Sasseville, A. A. Lackner, P. 0. Ilyinskii, M. D. Daniel, J. U. Jung, and R. C. Desrosiers, Cell 82:665-674, 1995). These properties are similar to those of the acutely lethal pathogen SIVpbj14 but dissimilar to those of the parental SIVmac239. We show here that the single change of R to Y at position 17 in nef of SIVmac239 is sufficient to confer the full, unusual phenotype. Conversely, the lymphocyte-activating properties of SIVpbj14 were lost by the single change of Y to R at position 17 of nef. The change of R17F or Q18E in SIVmac239 nef did not confer the unusual in vitro properties. Since SIVpbj14 has a duplication of the NF-kappaB binding sequence in the transcriptional control region, we also constructed and tested strains of SIVmac239/Rl7Y with zero, one, and two NF-kappaB binding elements. We found no difference in the properties of SIVmac239/R17Y, either in cell culture or in vivo, whether zero, one, or two NF-kappaB binding sites were present. Thus, tyrosine at position 17 of nef is absolutely necessary for the unusual phenotype of SIVpbj14 and is sufficient to convert SIVmac239 to a virus with a phenotype like that of SIVpbjl4. Multiple NF-kappaB binding sites are not required for the in vitro properties or for acute disease.
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PMID:Requirements for lymphocyte activation by unusual strains of simian immunodeficiency virus. 864 60

Simian immunodeficiency virus (SIV) infection in macaque species is typically associated with the development of a progressive immunodeficiency disease, similar to human AIDS, resulting in death of animals in months to years after infection. In contrast, a variant virus, termed SIVsmmPBj, induces an acute disease in macaques, resulting in death in 5 to 14 days after infection. Previously, we have shown that several viral determinants contribute to the pathogenesis of this disease. The present study was undertaken to evaluate the role of Nef in the pathogenesis of SIVsmmPBj-induced acute disease. A molecular clone of SIVsmmPBj was generated that contains a deletion in the nef coding region (PBj6.6 delta nef). Virus derived from this molecular clone was tested with the parental virus, PBj6.6, in replication studies in pigtail macaque and rhesus macaque peripheral blood mononuclear cells (PBMCs). In general, PBj6.6 delta nef displayed markedly reduced replication abilities when compared with PBj6.6; the only exception being in stimulated pigtail macaque PBMCs, where replication kinetics were nearly identical. In addition, PBj6.6 delta nef was unable to induce the proliferation of peripheral blood mononuclear cells (PBMCs) in vitro, a unique characteristic of acutely pathogenic SIVsmmPBj. Inoculation of this virus into pigtail macaques resulted in infection, but did not result in any detectable acute disease. These studies suggest that Nef is an important viral determinant in the pathogenesis of SIVsmmPBj-induced disease, and further suggest that Nef plays a significant role in viral replication in vivo.
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PMID:Deletion of the nef gene abrogates the ability of SIV smmPBj to induce acutely lethal disease in pigtail macaques. 874 83


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