RESUMO
CD40-CD40L interactions are critical for controlling Pneumocystis infection. However, which CD40-expressing cell populations are important for this interaction have not been well-defined. We used a cohousing mouse model of Pneumocystis infection, combined with flow cytometry and qPCR, to examine the ability of different populations of cells from C57BL/6 mice to reconstitute immunity in CD40 knockout (KO) mice. Unfractionated splenocytes, as well as purified B cells, were able to control Pneumocystis infection, while B cell depleted splenocytes and unstimulated bone-marrow derived dendritic cells (BMDCs) were unable to control infection in CD40 KO mice. Pneumocystis antigen-pulsed BMDCs showed early, but limited, control of infection. Consistent with recent studies that have suggested a role for antigen presentation by B cells, using cells from immunized animals, B cells were able to present Pneumocystis antigens to induce proliferation of T cells. Thus, CD40 expression by B cells appears necessary for robust immunity to Pneumocystis.
RESUMO
A subset of antiretroviral therapy-treated persons with human immunodeficiency virus (HIV), referred to as immunological nonresponders (INRs), fails to normalize CD4+ T-cell numbers. In a case-control study involving 26 INRs (CD4 < 250 cells/µL) and 25 immunological responders (IRs; CD4 ≥ 250 cells/µL), we evaluated the potential contribution of transcriptionally competent defective HIV-1 proviruses to poor CD4+ T-cell recovery. Compared to the responders, the INRs had higher levels of cell-associated HIV RNA (P = .034) and higher percentages of HLA-DR+ CD4+ T cells (P < .001). While not encoding replication-competent viruses, the RNA transcripts frequently encoded HIV-1 Gag-p17 and Nef proteins. These transcripts and/or resulting proteins may activate pathway(s) leading to the immunological nonresponse phenotype.
Assuntos
Linfócitos T CD4-Positivos , Infecções por HIV , HIV-1 , Provírus , Humanos , HIV-1/genética , HIV-1/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , Infecções por HIV/genética , Masculino , Estudos de Casos e Controles , Feminino , Adulto , Provírus/genética , Pessoa de Meia-Idade , Linfócitos T CD4-Positivos/imunologia , RNA Viral/genética , Contagem de Linfócito CD4 , Transcrição Gênica , Antirretrovirais/uso terapêutico , Terapia Antirretroviral de Alta AtividadeRESUMO
BACKGROUND: Data on cellular immune responses in persons with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection following vaccination are limited. The evaluation of these patients with SARS-CoV-2 breakthrough infections may provide insight into how vaccinations limit the escalation of deleterious host inflammatory responses. METHODS: We conducted a prospective study of peripheral blood cellular immune responses to SARS-CoV-2 infection in 21 vaccinated patients, all with mild disease, and 97 unvaccinated patients stratified based on disease severity. RESULTS: We enrolled 118 persons (aged 50 years [SD 14.5 years], 52 women) with SARS-CoV-2 infection. Compared to unvaccinated patients, vaccinated patients with breakthrough infections had a higher percentage of antigen-presenting monocytes (HLA-DR+), mature monocytes (CD83+), functionally competent T cells (CD127+), and mature neutrophils (CD10+); and lower percentages of activated T cells (CD38+), activated neutrophils (CD64+), and immature B cells (CD127+CD19+). These differences widened with increased disease severity in unvaccinated patients. Longitudinal analysis showed that cellular activation decreased over time but persisted in unvaccinated patients with mild disease at 8-month follow-up. CONCLUSIONS: Patients with SARS-CoV-2 breakthrough infections exhibit cellular immune responses that limit the progression of inflammatory responses and suggest mechanisms by which vaccination limits disease severity. These data may have implications for developing more effective vaccines and therapies. Clinical Trials Registration. NCT04401449.
Assuntos
COVID-19 , Humanos , Feminino , SARS-CoV-2 , Infecções Irruptivas , Estudos Prospectivos , VacinaçãoRESUMO
BACKGROUND: Pneumocystis jirovecii is an opportunistic fungus that causes Pneumocystis pneumonia (PCP) in immunocompromised hosts. Over an 11-month period, we observed a rise in cases of PCP among kidney-transplant recipients (KTR), prompting an outbreak investigation. METHODS: Clinical and epidemiologic data were collected for KTR diagnosed with PCP between July 2019 and May 2020. Pneumocystis strain typing was performed using restriction fragment length polymorphism analyses and multilocus sequence typing in combination with next-generation sequencing. A transmission map was drawn, and a case-control analysis was performed to determine risk factors associated with PCP. RESULTS: Nineteen cases of PCP in KTR were diagnosed at a median of 79 months post-transplantation; 8 received monthly belatacept infusions. Baseline characteristics were similar for KTR on belatacept versus other regimens; the number of clinic visits was numerically higher for the belatacept group during the study period (median 7.5 vs 3). Molecular typing of respiratory specimens from 9 patients revealed coinfection with up to 7 P. jirovecii strains per patient. A transmission map suggested multiple clusters of interhuman transmission. In a case-control univariate analysis, belatacept, lower absolute lymphocyte count, non-White race, and more transplant clinic visits were associated with an increased risk of PCP. In multivariate and prediction power estimate analyses, frequent clinic visits was the strongest risk factor for PCP. CONCLUSIONS: Increased clinic exposure appeared to facilitate multiple clusters of nosocomial PCP transmission among KTR. Belatacept was a risk factor for PCP, possibly by increasing clinic exposure through the need for frequent visits for monthly infusions.
Assuntos
Transplante de Rim , Pneumocystis carinii , Pneumonia por Pneumocystis , Surtos de Doenças , Humanos , Transplante de Rim/efeitos adversos , Tipagem de Sequências Multilocus , Pneumocystis carinii/genética , Pneumonia por Pneumocystis/microbiologia , Transplantados , Estados Unidos/epidemiologiaRESUMO
Although atovaquone is effective in treating and preventing Pneumocystis pneumonia (PCP), its use is limited by nonlinear absorption and adverse events. The current study was undertaken to examine the activity of encochleated atovaquone (eATQ), a novel lipid-crystal nanoparticle formulation, in a mouse model of PCP. eATQ 100-200 mg was superior to commercially available atovaquone at 14 days in decreasing total Pneumocystis nuclei and asci. eATQ plus anidulafungin reduced nuclei significantly better than commercial atovaquone plus anidulafungin. eATQ is a novel formulation of atovaquone that warrants further evaluation for treatment and prevention of PCP.
Assuntos
Antifúngicos , Atovaquona , Pneumonia por Pneumocystis , Anidulafungina/uso terapêutico , Animais , Antifúngicos/uso terapêutico , Atovaquona/uso terapêutico , Modelos Animais de Doenças , Camundongos , Pneumonia por Pneumocystis/tratamento farmacológico , Pneumonia por Pneumocystis/prevenção & controleRESUMO
A disease of more than 39.6 million people worldwide, HIV-1 infection has no curative therapy. To date, one man has achieved a sterile cure, with millions more hoping to avoid the potential pitfalls of lifelong antiretroviral therapy and other HIV-related disorders, including neurocognitive decline. Recent developments in immunotherapies and gene therapies provide renewed hope in advancing efforts toward a sterilizing or functional cure. On the horizon is research concentrated in multiple separate but potentially complementary domains: vaccine research, viral transcript editing, T-cell effector response targeting including checkpoint inhibitors, and gene editing. Here, we review the concept of targeting the HIV-1 tissue reservoirs, with an emphasis on the central nervous system, and describe relevant new work in functional cure research and strategies for HIV-1 eradication.
Assuntos
Reservatórios de Doenças , Infecções por HIV/terapia , HIV-1/fisiologia , Encéfalo , Sistemas CRISPR-Cas , Edição de Genes/métodos , Terapia Genética/métodos , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/genética , HIV-1/imunologia , Humanos , Latência ViralRESUMO
Previous studies have shown that Pneumocystis binds to pneumocytes, but the proteins responsible for binding have not been well defined. Mucins are the major glycoproteins present in mucus, which serves as the first line of defence during airway infection. MUC1 is the best characterised membrane-tethered mucin and is expressed on the surface of most airway epithelial cells. Although by electron microscopy Pneumocystis primarily binds to type I pneumocytes, it can also bind to type II pneumocytes. We hypothesized that Pneumocystis organisms can bind to MUC1 expressed by type II pneumocytes. Overexpression of MUC1 in human embryonic kidney HEK293 cells increased Pneumocystis binding, while knockdown of MUC1 expression by siRNA in A549 cells, a human adenocarcinoma-derived alveolar type II epithelial cell line, decreased Pneumocystis binding. Immunofluorescence labelling indicated that MUC1 and Pneumocystis were co-localised in infected mouse lung tissue. Incubation of A549 cells with Pneumocystis led to phosphorylation of ERK1/2 that increased with knockdown of MUC1 expression by siRNA. Pneumocystis caused increased IL-6 and IL-8 secretion by A549 cells, and knockdown of MUC1 further increased their secretion in A549 cells. Taken together, these results suggest that binding of Pneumocystis to MUC1 expressed by airway epithelial cells may facilitate establishment of productive infection.
Assuntos
Células Epiteliais/metabolismo , Mucina-1/metabolismo , Pneumocystis/metabolismo , Células A549 , Animais , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Pulmão , Sistema de Sinalização das MAP Quinases , Camundongos , Mucina-1/genética , Fosforilação , RNA Interferente Pequeno , TranscriptomaRESUMO
Pneumocystis, a unique atypical fungus with an elusive lifestyle, has had an important medical history. It came to prominence as an opportunistic pathogen that not only can cause life-threatening pneumonia in patients with HIV infection and other immunodeficiencies but also can colonize the lungs of healthy individuals from a very early age. The genus Pneumocystis includes a group of closely related but heterogeneous organisms that have a worldwide distribution, have been detected in multiple mammalian species, are highly host species specific, inhabit the lungs almost exclusively, and have never convincingly been cultured in vitro, making Pneumocystis a fascinating but difficult-to-study organism. Improved molecular biologic methodologies have opened a new window into the biology and epidemiology of Pneumocystis. Advances include an improved taxonomic classification, identification of an extremely reduced genome and concomitant inability to metabolize and grow independent of the host lungs, insights into its transmission mode, recognition of its widespread colonization in both immunocompetent and immunodeficient hosts, and utilization of strain variation to study drug resistance, epidemiology, and outbreaks of infection among transplant patients. This review summarizes these advances and also identifies some major questions and challenges that need to be addressed to better understand Pneumocystis biology and its relevance to clinical care.
Assuntos
Infecções por Pneumocystis/epidemiologia , Infecções por Pneumocystis/microbiologia , Pneumocystis/fisiologia , Classificação , Surtos de Doenças , Farmacorresistência Fúngica , Especificidade de Hospedeiro , Pneumocystis/classificaçãoRESUMO
Glucan is the major cell wall component of Pneumocystis cysts. In the current study, we have characterized Pneumocystis Bgl2 (EC 3.2.1.58), an enzyme with glucanosyltransferase and ß-1,3 endoglucanase activity in other fungi. Pneumocystis murina, Pneumocystis carinii, and Pneumocystis jirovecii bgl2 complementary DNA sequences encode proteins of 437, 447, and 408 amino acids, respectively. Recombinant P. murina Bgl2 expressed in COS-1 cells demonstrated ß-glucanase activity, as shown by degradation of the cell wall of Pneumocystis cysts. It also cleaved reduced laminaripentaose and transferred oligosaccharides, resulting in polymers of 6 and 7 glucan residues, demonstrating glucanosyltransferase activity. Surprisingly, confocal immunofluorescence analysis of P. murina-infected mouse lung sections using an antibody against recombinant Bgl2 showed that the native protein is localized primarily to the trophic form of Pneumocystis in both untreated mice and mice treated with caspofungin, an antifungal drug that inhibits ß-1,3-glucan synthase. Thus, like other fungi, Bgl2 of Pneumocystis has both endoglucanase and glucanosyltransferase activities. Given that it is expressed primarily in trophic forms, further studies are needed to better understand its role in the biology of Pneumocystis.
Assuntos
Antifúngicos/farmacologia , Caspofungina/farmacologia , Glucana Endo-1,3-beta-D-Glucosidase/metabolismo , Pneumocystis/enzimologia , Sequência de Aminoácidos , Animais , Ligante de CD40/genética , Células COS , Parede Celular/enzimologia , Chlorocebus aethiops , Glucana Endo-1,3-beta-D-Glucosidase/antagonistas & inibidores , Glucana Endo-1,3-beta-D-Glucosidase/genética , Glucanos/metabolismo , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pneumocystis/genética , Pneumocystis/imunologia , Pneumonia por Pneumocystis/imunologia , Proteínas Recombinantes , Alinhamento de SequênciaRESUMO
The major surface glycoprotein (Msg) is the most abundant surface protein among Pneumocystis species. Given that Msg is present on both the cyst and trophic forms of Pneumocystis and that dendritic cells play a critical role in initiating host immune responses, we undertook studies to examine activation of bone marrow-derived myeloid dendritic cells by Msg purified from Pneumocystis murina. Incubation of dendritic cells with Msg did not lead to increased expression of CD40, CD80, CD86, or major histocompatibility complex class II or to increased secretion of any of 10 cytokines. Microarray analysis identified very few differentially expressed genes. In contrast, lipopolysaccharide-activated dendritic cells had positive results of all of these assays. However, Msg did bind to mouse mannose macrophage receptor and human DC-SIGN, 2 C-type lectins expressed by dendritic cells that are important in recognition of pathogen-associated high-mannose glycoproteins. Deglycosylation of Msg demonstrated that this binding was dependent on glycosylation. These studies suggest that Pneumocystis has developed a mechanism to avoid activation of dendritic cells, potentially by the previously identified loss of genes that are responsible for the high level of protein mannosylation found in other fungi.
Assuntos
Células Dendríticas/efeitos dos fármacos , Proteínas Fúngicas/farmacologia , Glicoproteínas de Membrana/farmacologia , Pneumocystis/química , Animais , Células Cultivadas , Citocinas/análise , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Pneumocystis has a large multicopy gene family encoding proteins related to the major surface glycoprotein (Msg), whose functions are largely unknown. We expressed one such protein of Pneumocystis murina, p57, which is encoded by 3 highly conserved genes, and demonstrated by immunoblot that immunocompetent mice that were immunized with crude Pneumocystis antigens or that had cleared Pneumocystis infection developed antibodies to p57. Using hyperimmune anti-p57 serum combined with immunolabeling, we found that p57 was expressed by small trophic forms and intracystic bodies, whereas it was not expressed on larger trophic forms or externally by cysts. Expression of p57 and Msg by trophic forms was largely mutually exclusive. Treatment of infected animals with caspofungin inhibited cyst formation and markedly decreased p57 expression. While p57 expression was seen in immunocompetent mice infected with Pneumocystis, immunization with recombinant p57 did not result in altered cytokine expression by lymphocytes or in diminished infection in such mice. Thus, p57 appears to be a stage-specific antigen of Pneumocystis that is expressed on intracystic bodies and young trophic forms and may represent a mechanism to conserve resources in organisms during periods of limited exposure to host immune responses.
Assuntos
Anticorpos Antifúngicos/sangue , Antígenos de Fungos/imunologia , Infecções por Pneumocystis/imunologia , Pneumocystis/imunologia , Animais , Antígenos de Fungos/genética , Western Blotting , Modelos Animais de Doenças , Expressão Gênica , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Background: Once-weekly isoniazid and rifapentine for 3 months is a treatment option in persons with human immunodeficiency virus and latent tuberculosis infection. This study aimed to examine pharmacokinetic drug-drug interactions between this regimen and dolutegravir, a first-line antiretroviral medication. Methods: This was a single-center, open-label, fixed-sequence, drug-drug interaction study in healthy volunteers. Subjects received oral dolutegravir 50 mg once daily alone (days 1-4) and concomitantly with once-weekly isoniazid 900 mg, rifapentine 900 mg, and pyridoxine 50 mg (days 5-19). Dolutegravir concentrations were measured on days 4, 14, and 19, and rifapentine, 25-desacetyl-rifapentine, and isoniazid concentrations were measured on day 19. Cytokines and antidrug antibodies to isoniazid and rifapentine were examined at select time points. Results: The study was terminated following the development of flu-like syndrome and elevated aminotransferase levels in 2 of 4 subjects after the third isoniazid-rifapentine dose. Markedly elevated levels of interferon-γ, CXCL10, C-reactive protein, and other cytokines were temporally associated with symptoms. Antidrug antibodies were infrequently detected. Dolutegravir area under the curve (AUC) was decreased by 46% (90% confidence interval, 27-110%; P = .13) on day 14. Rifapentine and 25-desacetyl rifapentine levels on day 19 were comparable to reference data, whereas isoniazid AUCs were approximately 67%-92% higher in the subjects who developed toxicities. Conclusions: The combined use of dolutegravir with once-weekly isoniazid-rifapentine resulted in unexpected and serious toxicities that were mediated by endogenous cytokine release. Additional investigations are necessary to examine the safety and efficacy of coadministering these medications. Clinical Trials Registration: NCT02771249.
Assuntos
Antibióticos Antituberculose/efeitos adversos , Citocinas/imunologia , Esquema de Medicação , Compostos Heterocíclicos com 3 Anéis/efeitos adversos , Isoniazida/efeitos adversos , Rifampina/análogos & derivados , Adolescente , Adulto , Idoso , Antibióticos Antituberculose/farmacocinética , Citocinas/sangue , Interações Medicamentosas , Feminino , Infecções por HIV/microbiologia , Voluntários Saudáveis , Compostos Heterocíclicos com 3 Anéis/farmacocinética , Humanos , Isoniazida/farmacocinética , Tuberculose Latente/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Oxazinas , Piperazinas , Piridonas , Rifampina/efeitos adversos , Rifampina/farmacocinética , Adulto JovemRESUMO
Pneumocystis jirovecii can cause severe potentially life-threatening pneumonia (PCP) in kidney transplant patients. Prophylaxis of patients against PCP in this setting is usually performed during 6 months after transplantation. The aim of this study is to describe the molecular epidemiology of a cluster of PCP in renal transplant recipients in Brazil. Renal transplant patients who developed PCP between May and December 2011 had their formalin-fixed paraffin-embedded (FFPE) lung biopsy samples analysed. Pneumocystis jirovecii 23S mitochondrial large subunit of ribosomal RNA (23S mtLSU-rRNA), 26S rRNA, and dihydropteroate synthase (DHPS) genes were amplified by polymerase chain reaction (PCR), sequenced, and analysed for genetic variation. During the study period, 17 patients developed PCP (only four infections were documented within the first year after transplantation) and six (35.3%) died. Thirty FFPE samples from 11 patients, including one external control HIV-infected patient, had fungal DNA successfully extracted for further amplification and sequencing for all three genes. A total of five genotypes were identified among the 10 infected patients. Of note, four patients were infected by more than one genotype and seven patients were infected by the same genotype. DNA extracted from FFPE samples can be used for genotyping; this approach allowed us to demonstrate that multiple P. jirovecii strains were responsible for this cluster, and one genotype was found infecting seven patients. The knowledge of the causative agents of PCP may help to develop new initiatives for control and prevention of PCP among patients undergoing renal transplant and improve routine PCP prophylaxis.
Assuntos
Variação Genética , Transplante de Rim/efeitos adversos , Pneumocystis/isolamento & purificação , Pneumonia por Pneumocystis/microbiologia , Complicações Pós-Operatórias/microbiologia , Adulto , Brasil , Estudos Transversais , DNA Fúngico/genética , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Pneumocystis/classificação , Pneumocystis/genética , Pneumonia por Pneumocystis/diagnóstico , Complicações Pós-Operatórias/diagnóstico , Estudos Retrospectivos , Subunidades Ribossômicas Maiores/genética , Adulto JovemRESUMO
Pneumocystis remains an important pathogen of immunosuppressed patients, causing a potentially life-threatening pneumonia. Despite its medical importance, the immune responses required to control infection, including the role of interleukin-17 (IL-17), which is important in controlling other fungal infections, have not been clearly defined. Using flow cytometry and intracellular cytokine staining after stimulation with phorbol myristate acetate and ionomycin, we examined gamma interferon (IFN-γ), IL-4, IL-5, and IL-17 production by lung lymphocytes in immunocompetent C57BL/6 mice over time following infection with Pneumocystismurina We also examined the clearance of Pneumocystis infection in IL-17A-deficient mice. The production of both IFN-γ and IL-17 by pulmonary lymphocytes increased during infection, with maximum production at approximately days 35 to 40, coinciding with peak Pneumocystis levels in the lungs, while minimal changes were seen in IL-4- and IL-5-positive cells. The proportion of cells producing IFN-γ was consistently higher than for cells producing IL-17, with peak levels of â¼25 to 30% of CD3+ T cells for the former compared to â¼15% for the latter. Both CD4+ T cells and γδ T cells produced IL-17. Administration of anti-IFN-γ antibody led to a decrease in IFN-γ-positive cells, and an increase in IL-5-positive cells, but did not impact clearance of Pneumocystis infection. Despite the increases in IL-17 production during infection, IL-17A-deficient mice cleared Pneumocystis infection with kinetics similar to C57BL/6 mice. Thus, while IL-17 production in the lungs is increased during Pneumocystis infection in immunocompetent mice, IL-17A is not required for control of Pneumocystis infection.
Assuntos
Interleucina-17/análise , Pneumocystis/imunologia , Pneumonia por Pneumocystis/imunologia , Pneumonia por Pneumocystis/patologia , Linfócitos T/química , Linfócitos T/imunologia , Animais , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Interferon gama/análise , Interleucina-17/deficiência , Camundongos Endogâmicos C57BL , Camundongos Knockout , Coloração e RotulagemRESUMO
Human immunodeficiency virus and antiretroviral therapy (ART) together can be far more detrimental to liver cells than either of the two unaided. However, ultrastructural aspects of the synergistic effects of HIV and ART have been understudied. In a patient cohort receiving ART, this study characterizes ultrastructurally sinusoidal degeneration, hepatocytic aberrations, mitochondrial dysfunction, accumulation of bulky lipid droplets (steatosis), and occlusion of sinusoidal lumina. Mitochondrial dysfunction causes the accumulation of acetyl-CoA which leads to insulin upregulation and resistance, lipid synthesis, and steatosis. Lipid droplets deposited in the sinusoids could be the source of the blood's lipid profile alterations in HIV patients on ART.
Assuntos
Fármacos Anti-HIV/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/patologia , Endotélio/efeitos dos fármacos , Infecções por HIV/patologia , Hepatócitos/efeitos dos fármacos , Endotélio/patologia , Endotélio/ultraestrutura , Feminino , Infecções por HIV/tratamento farmacológico , Hepatócitos/patologia , Hepatócitos/ultraestrutura , Humanos , Masculino , Microscopia Eletrônica de Transmissão , Pessoa de Meia-IdadeRESUMO
ß-glucans, which can activate innate immune responses, are a major component in the cell wall of the cyst form of Pneumocystis In the current study, we examined whether ß-1,3-glucans are masked by surface proteins in Pneumocystis and what role ß-glucans play in Pneumocystis-associated inflammation. For 3 species, including Pneumocystis jirovecii, which causes Pneumocystis pneumonia in humans, Pneumocystis carinii, and Pneumocystis murina, ß-1,3-glucans were masked in most organisms, as demonstrated by increased exposure following trypsin treatment. Using quantitative polymerase chain reaction and microarray techniques, we demonstrated in a mouse model of Pneumocystis pneumonia that treatment with caspofungin, an inhibitor of ß-1,3-glucan synthesis, for 21 days decreased expression of a broad panel of inflammatory markers, including interferon γ, tumor necrosis factor α, interleukin 1ß, interleukin 6, and multiple chemokines/chemokine ligands. Thus, ß-glucans in Pneumocystis cysts are largely masked, which likely decreases innate immune activation; this mechanism presumably was developed for interactions with immunocompetent hosts, in whom organism loads are substantially lower. In immunosuppressed hosts with a high organism burden, organism death and release of glucans appears to be an important contributor to deleterious host inflammatory responses.
Assuntos
Pneumocystis/imunologia , Pneumonia por Pneumocystis/patologia , Pneumonia/patologia , beta-Glucanas/imunologia , Animais , Antifúngicos/administração & dosagem , Caspofungina , Citocinas/análise , Modelos Animais de Doenças , Equinocandinas/administração & dosagem , Lipopeptídeos/administração & dosagem , Camundongos Knockout , Análise em Microsséries , Pneumonia por Pneumocystis/microbiologia , Reação em Cadeia da Polimerase em Tempo RealRESUMO
BACKGROUND: The current study was conducted to determine if efavirenz (EFV) or atazanavir/ritonavir (ATV/r)-based combination antiretroviral therapy (cART) impacted steady-state atovaquone plasma concentrations in human immunodeficiency virus (HIV)-infected patients receiving treatment doses of atovaquone. METHODS: Thirty HIV-infected volunteers were recruited, 10 taking no cART and 10 each taking cART that included EFV or ATV/r. Subjects were randomly assigned to atovaquone 750 mg twice daily (BID) for 14 days followed by atovaquone 1500 mg BID for 14 days, or vice-versa, with a washout period in between. On day 14 of each phase, blood was sampled for pharmacokinetic studies, and the area under the concentration-time curve (AUCτ) and average concentration (C avg) were calculated and compared using an unpaired t test. RESULTS: Twenty-nine subjects completed both dosing cohorts. Subjects receiving EFV-based cART had 47% and 44% lower atovaquone AUCτ than subjects not receiving cART at atovaquone doses of 750 mg BID and 1500 mg BID, respectively (P≤ .01). Only 5 of 10 subjects receiving EFV-based cART plus atovaquone 750 mg BID had an atovaquone C avg>15 µg/mL, which has previously been associated with successful treatment of Pneumocystis jirovecipneumonia. AUCτ and Cavg did not significantly differ for concurrent ATV/r for 750 mg BID or 1500 mg BID when compared to the group not receiving cART. Nine of 10 subjects not receiving cART, 8 of 10 subjects receiving ATV/r, and 2 of 10 subjects receiving EFV in combination with atovaquone 750 mg BID achieved an atovaquone C avg>18.5 µg/mL, a concentration that has previously been associated with successful treatment of Toxoplasmaencephalitis (TE). CONCLUSIONS: These data suggest that the currently recommended dose of atovaquone 750 mg BID for treatment of mild to moderate PCP may not be adequate in patients receiving concurrent EFV. Furthermore, doses lower than the currently recommended dose of 1500 mg BID may achieve plasma concentrations adequate to treat TE in HIV-infected patients not receiving EFV. CLINICAL TRIALS REGISTRATION: NCT01479361.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Anti-Infecciosos/farmacocinética , Anti-Infecciosos/uso terapêutico , Atovaquona/farmacocinética , Atovaquona/uso terapêutico , Benzoxazinas/uso terapêutico , Ritonavir/uso terapêutico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Idoso , Alcinos , Anti-Infecciosos/sangue , Sulfato de Atazanavir/efeitos adversos , Sulfato de Atazanavir/uso terapêutico , Atovaquona/sangue , Benzoxazinas/efeitos adversos , Ciclopropanos , Interações Medicamentosas , Quimioterapia Combinada/efeitos adversos , Encefalite/tratamento farmacológico , Encefalite/prevenção & controle , Feminino , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/efeitos adversos , Inibidores da Protease de HIV/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia por Pneumocystis/tratamento farmacológico , Pneumonia por Pneumocystis/prevenção & controle , Inibidores da Transcriptase Reversa/efeitos adversos , Inibidores da Transcriptase Reversa/uso terapêutico , Ritonavir/efeitos adversos , Toxoplasmose Cerebral/tratamento farmacológico , Toxoplasmose Cerebral/prevenção & controle , Adulto JovemRESUMO
BACKGROUND: Chronic liver injury can result in fibrosis that may progress over years to end-stage liver disease. The most effective anti-fibrotic therapy is treatment of the underlying disease, however when not possible, interventions to reverse or slow fibrosis progression are needed. AIM: The aim of this study was to study the safety and tolerability of simtuzumab, a monoclonal antibody directed against lysyl oxidase-like 2 (LOXL2) enzyme, in subjects with hepatitis C virus (HCV), human immunodeficiency virus (HIV), or HCV-HIV co-infection and advanced liver disease. METHODS: Eighteen subjects with advanced liver fibrosis received simtuzumab 700 mg intravenously every 2 weeks for 22 weeks. Transjugular liver biopsies were performed during screening and at the end of treatment to measure hepatic venous pressure gradient (HVPG) and to stage fibrosis. RESULTS: Treatment was well-tolerated with no discontinuations due to adverse events. No significant changes were seen in HVPG or liver biopsy fibrosis score after treatment. Exploratory transcriptional and protein profiling using paired pre- and post-treatment liver biopsy and serum samples suggested up-regulation of TGF-ß3 and IL-10 pathways with treatment. CONCLUSION: In this open-label, pilot clinical trial, simtuzumab treatment was well-tolerated in HCV- and HIV-infected subjects with advanced liver disease. Putative modulation of TGF-ß3 and IL-10 pathways during simtuzumab treatment merits investigation in future trials.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Coinfecção/complicações , Infecções por HIV/complicações , Hepatite C Crônica/complicações , Cirrose Hepática/tratamento farmacológico , Administração Intravenosa , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Coinfecção/virologia , Progressão da Doença , Feminino , Humanos , Interleucina-10/sangue , Fígado/patologia , Cirrose Hepática/virologia , Masculino , Maryland , Pessoa de Meia-Idade , Pressão na Veia Porta/efeitos dos fármacos , Fator de Crescimento Transformador beta3/sangue , Resultado do TratamentoRESUMO
ß-1,3-glucan is a major cell wall component of Pneumocystis cysts. We have characterized endo-ß-1,3-glucanase (Eng) from 3 species of Pneumocystis. The gene eng is a single-copy gene that encodes a protein containing 786 amino acids in P. carinii and P. murina, and 788 amino acids in P. jirovecii, including a signal peptide for the former 2 but not the latter. Recombinant Eng expressed in Escherichia coli was able to solubilize the major surface glycoprotein of Pneumocystis, thus potentially facilitating switching of the expressed major surface glycoprotein (Msg) variant. Confocal immunofluorescence analysis of P. murina-infected mouse lung sections localized Eng exclusively to the cyst form of Pneumocystis. No Eng was detected after mice were treated with caspofungin, a ß-1,3-glucan synthase inhibitor that is known to reduce the number of cysts. Thus, Eng is a cyst-specific protein that may play a role in Msg variant expression in Pneumocystis.
Assuntos
Regulação Fúngica da Expressão Gênica , Glucana Endo-1,3-beta-D-Glucosidase/biossíntese , Pneumocystis/enzimologia , Esporos Fúngicos/enzimologia , Animais , Escherichia coli/genética , Expressão Gênica , Glucana Endo-1,3-beta-D-Glucosidase/genética , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Microscopia Confocal , Microscopia de Fluorescência , Pneumocystis/genética , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Esporos Fúngicos/genéticaRESUMO
BACKGROUND: Persistent aminotransferase elevations are common in human immunodeficiency virus (HIV)-infected patients on antiretroviral therapy (ART), including those without hepatitis B or C coinfection, but their clinical significance is unknown. METHODS: HIV-infected adults with aminotransferase levels elevated above the upper limit of normal for ≥6 months while receiving ART, and without chronic viral hepatitis or other known causes of chronic liver disease, underwent a detailed metabolic assessment and liver biopsy. RESULTS: Sixty-two HIV-infected subjects completed the study. Forty (65%) had clinically significant liver pathology, including 34 (55%) with nonalcoholic steatohepatitis (NASH) and 11 (18%) with bridging fibrosis, 10 of whom also had NASH. Nonspecific abnormalities alone were seen in 22 (35%) subjects, including mild steatosis, mild to moderate inflammation, and evidence of drug adaptation. Insulin resistance, obesity, and the presence of either of 2 minor alleles in the PNPLA3 gene were significantly associated with increased risk of NASH and fibrosis. NASH and/or fibrosis were not associated with duration of HIV infection or ART, specific antiretroviral drugs, history of opportunistic infection, immune status, or duration of aminotransferase elevation. CONCLUSIONS: HIV-infected adults with chronic aminotransferase elevations while receiving ART have a high rate of liver disease. Noninvasive testing can help identify liver disease in such patients, but liver biopsy is necessary to definitively identify those at risk for liver disease progression and complications. Longitudinal follow-up of this cohort will better characterize the natural history of aminotransferase elevations in this population and identify noninvasive biomarkers of liver disease progression.