RESUMO
Central nervous system histoplasmosis is a serious complication of a common endemic mycosis, but it is rare in immunocompetent hosts. SARS-CoV-2 has introduced significant challenges into the healthcare setting with overlapping clinical presentations that may delay the diagnosis of alternative conditions. Additionally, it may lead to immune dysregulation and increase the risk for secondary infections, including invasive fungal diseases. Limited reports have described disseminated histoplasmosis in adults associated with COVID-19, but none have described central nervous system infection or complications in pediatric patients. We report a case of disseminated histoplasmosis involving the central nervous system in a previously healthy 13-year-old male with SARS-CoV-2 infection. An extensive immunological evaluation did not identify an underlying immunodeficiency. We highlight the potential of COVID-19 immune dys-regulation to contribute to the development or progression of invasive fungal disease. [Pediatr Ann. 2024;53(8):e305-e309.].
Assuntos
COVID-19 , Infecções Fúngicas do Sistema Nervoso Central , Histoplasmose , Humanos , Adolescente , Histoplasmose/diagnóstico , Histoplasmose/tratamento farmacológico , Histoplasmose/complicações , Masculino , COVID-19/complicações , COVID-19/diagnóstico , Infecções Fúngicas do Sistema Nervoso Central/diagnóstico , Antifúngicos/uso terapêutico , SARS-CoV-2RESUMO
Amino-amides are important pharmaceutical building-blocks. The enantioselective reduction of trichloromethyl ketones using ruthenium transfer hydrogenation catalysts is reported. The products react in a range of Jocic-type reactions to give enantiomerically enriched amino-amides.
Assuntos
Amidas/química , Aminas/química , Clorofórmio/química , Cetonas/química , Catálise , Hidrogenação , Estrutura Molecular , Oxirredução , Rutênio/química , EstereoisomerismoRESUMO
The HLA-B57 allele family is associated with slow progression to disease in HIV-1-infected individuals and restricts a potent CD8 response against the p24 protein. This study was designed to assess the sequence variation and the CD8 response against B57-restricted epitopes of the p24 protein in a cohort of HIV-1 subtype C-infected individuals possessing a high frequency of the B5703 allele. Gag sequences were amplified by PCR, cloned, and sequenced from 19 individuals including 8 B57-negative individuals. CD8 responses were assessed by interferon-gamma ELISPOT assay directly from PBMC using synthetic peptides matching the autologous virus as well as the peptides representing the sequence variants circulating within the B5703 individuals. The KF11 epitope (p24 amino acids 162-172) and variants of this epitope were immunodominant in subjects possessing the B5703 allele. Three variants were observed only in B5703 individuals. Differing patterns of cross-reactivity against variant peptides were observed and were dependent upon the sequence of the autologous virus. Subjects infected with the A2G, S4N variant of KF11 demonstrated poor cross-reactivity against all other variant peptides. Determination of the breadth of viral quasispecies circulating in a population provided crucial information for studying potential escape variants of an immunodominant epitope. The presented data show that the sequence of autologous virus is critical in determining the extent of cross-reactivity of a CD8 T cell response against heterologous virus variants. Efforts to optimize the cross-reactivity of vaccine-induced CD8 T cells may need to focus on the relative immunogenicity of minor sequence variation.
Assuntos
Síndrome da Imunodeficiência Adquirida/imunologia , Linfócitos T CD8-Positivos/imunologia , Proteína do Núcleo p24 do HIV/imunologia , HIV-1/classificação , Antígenos HLA-B/imunologia , Epitopos Imunodominantes , Alelos , Reações Cruzadas , HIV-1/imunologia , Antígenos HLA-B/genética , HumanosRESUMO
A cohort of 35 human immunodeficiency virus type 1 (HIV-1) subtype C-infected Ethiopians was studied to define the HLA phenotype in all 35 subjects and highly conserved Gag protein regions involved in cross-clade cell-mediated immunity. Full-length Gag virus sequences were determined in 15 individuals. CD8 cell-mediated immune responses were detected by interferon-gamma ELISpot assay. HLA-A*03, -B*49, and -B*57 allelic frequencies were relatively higher than in other African populations. Anti-p17 (aa 1-60) CD8+ were detectable in the highest number of individuals. Anti-p17 (aa 1-60 and 51-110) cross-clade responses against subtype B and C were detected in 50% of the tested subjects. The p24 KF11 (aa 162-172) epitope was found to be immunodominant among the HLA-B*5703--positive individuals. These data represent the first report of correlating HLA phenotype and HIV-specific cell-mediated immune responses among infected Ethiopians and may be useful in designing cytotoxic T lymphocyte-inducing vaccines for this part of Africa.
Assuntos
Produtos do Gene gag/imunologia , Infecções por HIV/genética , HIV-1/imunologia , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Imunidade Celular/genética , Vacinas contra a AIDS/imunologia , Etiópia , Feminino , Produtos do Gene gag/genética , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/genética , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Humanos , Imunidade Celular/imunologia , Interferon gama/imunologia , Masculino , Fenótipo , Linfócitos T Citotóxicos/imunologiaRESUMO
The impact of HIV-1 genetic diversity on candidate vaccines is uncertain. One approach to minimize genetic diversity in the evaluation of HIV-1 vaccines is to match the vaccine sequence to the predominant subtype in a vaccine cohort. Over two million Ethiopians are infected with HIV-1, and the predominant subtype is thought to be subtype C. Understanding the phylogenetic relationships between sequences from Ethiopia and within subtype C can help decide what sequence(s) should comprise a candidate vaccine. To that end, nearly full genome sequencing was used to characterize HIV-1 from volunteers who emigrated from Ethiopia. DNA extracted from peripheral blood mononuclear cells (PMBC) was amplified using primers in the long terminal repeats to generate nearly full-length genomes. Amplicons were directly sequenced with dye terminators and automated sequencers. Sequences were phylogenetically analyzed by neighbor joining. The six new Ethiopian sequences were all subtype C, consistent with previous partial and full genome analysis. Together with two other Ethiopian sequences, the new sequences formed a geographic cluster when the complete genome was analyzed. However, subgenomic trees showed only a weak geographic cluster, or none, with respect to Ethiopian strains. Although immunological responses must be considered, from a phylogenetic perspective, there is no compelling support for use of Ethiopian subtype C sequences, compared to other subtype C, as vaccine prototype strains.
Assuntos
Genoma Viral , Infecções por HIV/virologia , HIV-1/genética , Análise de Sequência de DNA , Sequência de Bases , Estudos de Coortes , DNA Viral/análise , DNA Viral/química , Etiópia , Infecções por HIV/epidemiologia , HIV-1/classificação , Humanos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , FilogeniaRESUMO
The impact of HIV-1 genetic diversity on candidate vaccines is uncertain. To minimize genetic diversity in the evaluation of HIV-1 vaccines, vaccine products must be matched to the predominant subtype in a vaccine cohort. To that end, full genome sequencing was used to detect and characterize HIV-1 subtypes and recombinant strains from individuals in Rakai District, Uganda. DNA extracted from peripheral blood mononuclear cells (PMBC) was PCR amplified using primers in the long terminal repeats (LTRs) to generate nearly full length genomes. Amplicons were directly sequenced with dye terminators and automated sequencers. Sequences were phylogenetically analyzed and recombinants were detected and mapped with distance scan and bootscan. Among 46 sequences, 54% were subtype D, 15% were subtype A, and 30% were recombinant. All recombinants were individually unique, and most combined subtypes A and D. Subtype D comprised more than 70% of all the HIV-1 genomes in Rakai when both pure subtypes and recombinants were considered. Candidate vaccines based on HIV-1 subtype D would be appropriate for evaluation in Rakai District, Uganda.
Assuntos
DNA Viral/química , Genoma Viral , HIV-1/classificação , HIV-1/genética , Adolescente , Adulto , Sequência de Bases , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Filogenia , Recombinação Genética , UgandaRESUMO
OBJECTIVE: To enable more rapid and efficient genotyping of HIV-1 in East Africa, where subtypes A, C, and D and their recombinants are co-circulating. DESIGN: Full-genome sequencing of HIV-1 provides complete discrimination of subtypes and recombinant forms but is costly and low-throughput compared to other genotyping approaches. Here we describe the development and evaluation of a Multi-region Hybridization Assay (MHA) for the efficient determination of HIV-1 subtypes A, C, D, recombinants, and dual infections. METHODS: Five genome regions containing clustered mutations distinguishing subtypes A, C, and D were identified and used to design subtype-specific probes. DNA from primary peripheral blood mononuclear cells was used as template for real-time PCR using the fluorescent, subtype-specific probes. RESULTS: A panel of 45 clinical samples from Uganda, Kenya, and Tanzania, previously characterized by full-genome sequencing and including 26 pure subtypes and 19 recombinant strains, was evaluated by MHA. The MHA provided 90% sensitivity and 98% specificity for the three subtypes, efficiently discriminated subtypes from recombinant forms, and detected several dual infections. CONCLUSIONS: Accurate and efficient genotyping of HIV-1 strains in vaccine trial populations in East Africa, ascertainment of dual infections, and elucidation of the genesis of recombinant forms in individuals can be facilitated by the application of MHA.
Assuntos
Infecções por HIV/complicações , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , Recombinação Genética , África Oriental , Sequência de Bases , Sondas de DNA , Genótipo , Humanos , Hibridização de Ácido Nucleico/métodos , Sensibilidade e Especificidade , Análise de Sequência de DNARESUMO
Viruses often contain cis-acting RNA elements, which facilitate the posttranscriptional processing and export of their messages. These elements fall into two classes distinguished by the presence of either viral or cellular RNA binding proteins. To date, studies have indicated that the viral proteins utilize the CRM1-dependent export pathway, while the cellular factors generally function in a CRM1-independent manner. The cis-acting element found in the woodchuck hepatitis virus (WHV) (the WHV posttranscriptional regulatory element [WPRE]) has the ability to posttranscriptionally stimulate transgene expression and requires no viral proteins to function. Conventional wisdom suggests that the WPRE would function in a CRM1-independent manner. However, our studies on this element reveal that its efficient function is sensitive to the overexpression of the C terminus of CAN/Nup214 and treatment with the antimicrobial agent leptomycin B. Furthermore, the overexpression of CRM1 stimulates WPRE activity. These results suggest a direct role for CRM1 in the export function of the WPRE. This observation suggests that the WPRE is directing messages into a CRM1-dependent mRNA export pathway in somatic mammalian cells.