Search results for "HIV-1"

CD3ε Expression Defines Functionally Distinct Subsets of Vδ1 T Cells in Patients With Human Immunodeficiency Virus Infection

2018

Human γδ T cells expressing the Vδ1 T cell receptor (TCR) recognize self and microbial antigens and stress-inducible molecules in a major histocompatibility complex -unrestricted manner and are an important source of innate interleukin-17. Vδ1 T cells are expanded in the circulation and intestines of patients with human immunodeficiency virus (HIV) infection. In the present study, we show that patients with HIV have elevated frequencies, but not absolute numbers, of circulating Vδ1 T cells compared to control subjects. This increase was most striking in the patients with Candida albicans co-infection. Using flow cytometry and confocal microscopy, we identify two populations of Vδ1 T cells, …

Evaluation of HIV transmission clusters among natives and foreigners living in Italy

2020

We aimed at evaluating the characteristics of HIV-1 molecular transmission clusters (MTCs) among natives and migrants living in Italy, diagnosed between 1998 and 2018. Phylogenetic analyses were performed on HIV-1 polymerase (pol) sequences to characterise subtypes and identify MTCs, divided into small (SMTCs, 2&ndash

A Naturally Occurring Antibody Fragment Neutralizes Infectivity of Diverse Infectious Agents

2016

AbstractA phosphorylated peptide, named K40H, derived from the constant region of IgMs was detected in human serum by liquid chromatography coupled to high-resolution mass spectrometry. Synthetic K40H proved to exert a potent in vitro activity against fungal pathogens, and to inhibit HIV-1 replication in vitro and ex vivo. It also showed a therapeutic effect against an experimental infection by Candida albicans in the invertebrate model Galleria mellonella. K40H represents the proof of concept of the innate role that naturally occurring antibody fragments may exert against infectious agents, shedding a new light upon the posthumous role of antibodies and opening a new scenario on the multif…

Genome-scale analysis of evolutionary rate and selection in a fast-expanding Spanish cluster of HIV-1 subtype F1.

2018

Abstract This work is aimed at assessing the presence of positive selection and/or shifts of the evolutionary rate in a fast-expanding HIV-1 subtype F1 transmission cluster affecting men who have sex with men in Spain. We applied Bayesian coalescent phylogenetics and selection analyses to 23 full-coding region sequences from patients belonging to that cluster, along with other 19 F1 epidemiologically-unrelated sequences. A shift in the overall evolutionary rate of the virus, explained by positively selected sites in the cluster, was detected. We also found one substitution in Nef (H89F) that was specific to the cluster and experienced positive selection. These results suggest that fast tran…

How can the gut microbiota affect immune recovery in HIV-infected individuals?

2017

The substitution rate of HIV-1 subtypes: a genomic approach

2017

Abstract HIV-1M causes most infections in the AIDS pandemic. Its genetic diversity is defined by nine pure subtypes and more than sixty recombinant forms. We have performed a comparative analysis of the evolutionary rate of five pure subtypes (A1, B, C, D, and G) and two circulating recombinant forms (CRF01_AE and CRF02 AG) using data obtained from nearly complete genome coding sequences. Times to the most recent common ancestor (tMRCA) and substitution rates of these HIV genomes, and their genomic partitions, were estimated by Bayesian coalescent analyses. Genomic substitution rate estimates were compared between the HIV-1 datasets analyzed by means of randomization tests. Significant diff…

Pre-ART HIV-1 DNA in CD4+ T cells correlates with baseline viro-immunological status and outcome in patients under first-line ART

2018

Objectives We evaluated the association between pre-ART HIV DNA and HIV-infected participant characteristics at baseline as well as with their response to first-line ART. Methods Four hundred and thirty-three patients from the ICONA cohort, starting first-line ART after the year 2000, were analysed. Pre-ART HIV DNA was quantified with the modified COBAS TaqMan HIV-1 Test and normalized by CD4+ T cells. Linear correlation between pre-ART HIV DNA and other continuous markers (HIV RNA, CD4 count, markers of inflammation and coagulation) at baseline was evaluated by means of Pearson correlation coefficient and a linear regression model. Survival analyses and Cox regression models were used to s…

HLA-E-Restricted CD8+ T Lymphocytes Efficiently Control Mycobacterium tuberculosis and HIV-1 Co-Infection

2020

We investigated the contribution of human leukocyte antigen A2 (HLA-A2) and HLA-E-restricted CD8+ T cells in patients with Mycobacterium tuberculosis and human immunodeficiency virus 1 (HIV-1) coinfection. HIV-1 downregulates HLA-A, -B, and -C molecules in infected cells, thus influencing recognition by HLA class I-restricted CD8+ T cells but not by HLA-E-restricted CD8+ T cells, owing to the inability of the virus to downmodulate their expression. Therefore, antigen-specific HLA-E-restricted CD8+ T cells could play a protective role in Mycobacterium tuberculosis and HIV-1 coinfection. HLA-E- and HLA-A2-restricted Mycobacterium tuberculosis-specific CD8+ T cells were tested in vitro for cyt…

Identification of a large, fast-expanding HIV-1 subtype B transmission cluster among MSM in Valencia, Spain

2017

We describe and characterize an exceptionally large HIV-1 subtype B transmission cluster occurring in the Comunidad Valenciana (CV, Spain). A total of 1806 HIV-1 protease-reverse transcriptase (PR/RT) sequences from different patients were obtained in the CV between 2004 and 2014. After subtyping and generating a phylogenetic tree with additional HIV-1 subtype B sequences, a very large transmission cluster which included almost exclusively sequences from the CV was detected (n = 143 patients). This cluster was then validated and characterized with further maximum-likelihood phylogenetic analyses and Bayesian coalescent reconstructions. With these analyses, the CV cluster was delimited to 11…

Harnessing Unconventional T Cells for Immunotherapy of Tuberculosis

2020

Even if the incidence of tuberculosis (TB) has been decreasing over the last years, the number of patients with TB is increasing worldwide. The emergence of multidrug-resistant and extensively drug-resistant TB is making control of TB more difficult. Mycobacterium bovis bacillus Calmette–Guérin vaccine fails to prevent pulmonary TB in adults, and there is an urgent need for a vaccine that is also effective in patients with human immunodeficiency virus (HIV) coinfection. Therefore, TB control may benefit on novel therapeutic options beyond antimicrobial treatment. Host-directed immunotherapies could offer therapeutic strategies for patients with drug-resistant TB or with HIV and TB coinfecti…