Background
Dolutegravir (DTG) monotherapy results in virologic failure and the development of DTG resistance. Here, we evaluated virologic outcomes of patients switched to DTG functional mono- or dual therapy with a non-cytosine nucleoside analog (NA).
Methods
This retrospective, single center study included treatment-experienced patients switched to regimens containing ≥ 2 antiretrovirals between 8/13/13–11/22/14 who were later found to be on DTG functional mono- or dual therapy with a non-cytosine NA based on historical genotypes. Eligible patients were either suppressed or viremic at baseline and had ≥ 2 HIV-1 RNA measurements at least 4 weeks apart following switch. Demographics, laboratory values and clinical parameters were extracted from the charts of all eligible patients during study treatment until 12/31/2018 and were summarized using descriptive statistics. The primary endpoint was the proportion of patients with HIV-1 RNA < 50 copies/mL following switch.
Results
Of 70 patients switched to DTG functional mono- or dual therapy, 39 were eligible; 19 (49%) were on DTG functional monotherapy and 20 (51%) were on DTG functional dual therapy with a non-cytosine NA. Historical genotypes indicated that all had an M184V/I, and 23 (59%) had an M184V/I and ≥ 1 additional NA mutation. The median duration of follow-up on study treatment was 50 weeks (range 12–244). Following switch, 32/39 (82%) patients achieved or maintained an HIV-1 RNA < 50 copies/mL and 7 (18%) had persistent HIV-1 RNA ≥ 50 copies/mL. Five viremic patients were found to be on functional dual therapy with DTG plus a non-cytosine NA and 2 were on DTG functional monotherapy. Five of these patients had post-switch genotypes ordered as a part of routine clinical care and there was no evidence of treatment-emergent resistance. Five were switched to a different DTG-containing regimen and achieved HIV-1 RNA < 50 copies/mL, 1 was switched to a non-DTG containing regimen and achieved HIV-1 RNA < 50 copies/mL and 1 was lost-to-follow up at week 36.
Conclusions
In this real-world cohort, the majority of whom had virus with the M184V/I and ≥ 1 additional NA mutation, switching to DTG functional mono-or dual therapy with a non-cytosine NA resulted in persistent HIV-1 RNA ≥ 50 copies/mL in 18%. None with post-switch genotypes developed treatment-emergent resistance.
Pseudomonas aeruginosa is a prevalent pathogen in cystic fibrosis (CF) lungs which displays strong resistance to various antibiotic classes, contributing to antimicrobial resistance (AMR). P aeruginosa populations in CF lungs exhibit considerable genetic and phenotypic diversity, raising questions about their susceptibility to non-traditional antimicrobials, such as bacteriocins. R-pyocins, bacteriocins produced by P. aeruginosa, are highly potent, non-replicating phage tail-like protein complexes with a narrow killing spectrum. The diversity of P. aeruginosa variants within CF lung infections may lead to varying susceptibility to R-pyocins due to changes in the lipopolysaccharide (LPS) structure, which acts as the R-pyocin receptor. However, the extent of susceptibility to the five known R-pyocin subtypes (R1-R5) remains unknown, especially considering the diverse P. aeruginosa populations in CF lungs. Additionally, the connection between LPS phenotype and R-pyocin susceptibility is not well understood. We tested 139 P. aeruginosa variants from 17 sputum samples of seven CF patients for R2-pyocin susceptibility and analyzed their LPS phenotypes. Our findings revealed that approximately 83% of sputum samples contained diverse P. aeruginosa populations without R2-pyocin resistant variants, while all samples had some susceptible variants. Moreover, there was no clear correlation between LPS phenotypes and R-pyocin susceptibility. The absence of a clear correlation between LPS phenotypes and R-pyocin susceptibility suggests that LPS packing density may significantly influence R-pyocin susceptibility among CF variants. Our research supports the potential use of R-pyocins as therapeutic agents, as numerous infectious CF variants appear to be susceptible to R2-pyocins, even within diverse P. aeruginosa populations.
Treponema pallidum subsp. endemicum (TEN) is the causative agent of endemic syphilis (bejel). Until now, only a single TEN strain, Bosnia A, has been completely sequenced. The only other laboratory TEN strain available, Iraq B, was isolated in Iraq in 1951 by researchers from the US Centers for Disease Control and Prevention. In this study, the complete genome of the Iraq B strain was amplified as overlapping PCR products and sequenced using the pooled segment genome sequencing method and Illumina sequencing. Total average genome sequencing coverage reached 3469×, with a total genome size of 1,137,653 bp. Compared to the genome sequence of Bosnia A, a set of 37 single nucleotide differences, 4 indels, 2 differences in the number of tandem repetitions, and 18 differences in the length of homopolymeric regions were found in the Iraq B genome. Moreover, the tprF and tprG genes that were previously found deleted in the genome of the TEN Bosnia A strain (spanning 2.3 kb in length) were present in a subpopulation of TEN Iraq B and Bosnia A microbes, and their sequence was highly similar to those found in T. p. subsp. pertenue strains, which cause the disease yaws. The genome sequence of TEN Iraq B revealed close genetic relatedness between both available bejel-causing laboratory strains (i.e., Iraq B and Bosnia A) and also genetic variability within the bejel treponemes comparable to that found within yaws- or syphilis-causing strains. In addition, genetic relatedness to TPE strains was demonstrated by the sequence of the tprF and tprG genes found in subpopulations of both TEN Iraq B and Bosnia A. The loss of the tprF and tprG genes in most TEN microbes suggest that TEN genomes have been evolving via the loss of genomic regions, a phenomenon previously found among the treponemes causing both syphilis and rabbit syphilis.
Dengue virus (DENV) is the most prevalent arthropod-borne viral disease in humans. DENV causes a spectrum of illness ranging from mild to potentially severe complications. Dendritic cells (DCs) play a critical role in initiating and regulating highly effective antiviral immune response that include linking innate and adaptive immune responses. This study was conducted to comparatively characterize in detail the relative proportion, phenotypic changes, and maturation profile of subsets of both myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in children with dengue fever (DF), dengue hemorrhagic fever (DHF) and for purposes of control healthy individuals. The mDCs (Lin-CD11c+CD123lo), the pDCs (Lin-CD11c-CD123+) and the double negative (DN) subset (Lin-/HLA-DR+/CD11c-CD123-) were analyzed by polychromatic flow cytometry. The data were first analyzed on blood samples collected from DENV-infected patients at various times post-infection. Results showed that the relative proportion of mDCs were significantly decreased which was associated with an increase in disease severity in samples from DENV-infected patients. While there was no significant difference in the relative proportion of pDCs between healthy and DENV-infected patients, there was a marked increase in the DN subset. Analysis of the kinetics of changes of pDCs showed that there was an increase but only during the early febrile phase. Additionally, samples from patients during acute disease showed marked decreases in the relative proportion of CD141+and CD16+mDC subsets that were the major mDC subsets in healthy individuals. In addition, there was a significant decrease in the level of CD33-expressing mDCs in DENV patients. While the pDCs showed an up-regulation of maturation profile during acute DENV infection, the mDCs showed an alteration of maturation status. This study suggests that different relative proportion and phenotypic changes as well as alteration of maturation profile of DC subsets may play a critical role in the dengue pathogenesis and disease outcome.
by
Julia Merkenschlager;
Mickaël J. Ploquin;
Urszula Eksmond;
Rakieb Andargachew;
Georgina Thorborn;
Andrew Filby;
Marion Pepper;
Brian Evavold;
George Kassiotis
Antigen receptor diversity underpins adaptive immunity by providing the ground for clonal selection of lymphocytes with the appropriate antigen reactivity. Current models attribute T cell clonal selection during the immune response to T-cell receptor (TCR) affinity for either foreign or self peptides. Here, we report that clonal selection of CD4+ T cells is also extrinsically regulated by B cells. In response to viral infection, the antigen-specific TCR repertoire is progressively diversified by staggered clonotypic expansion, according to functional avidity, which correlates with self-reactivity. Clonal expansion of lower-avidity T-cell clonotypes depends on availability of MHC II-expressing B cells, in turn influenced by B-cell activation. B cells clonotypically diversify the CD4+ T-cell response also to vaccination or tumour challenge, revealing a common effect.
Hyphal growth is essential for host colonization during Aspergillus infection. The transcription factor ZfpA regulates A. fumigatus hyphal development including branching, septation, and cell wall composition. However, how ZfpA affects fungal growth and susceptibility to host immunity during infection has not been investigated. Here, we use the larval zebrafish-Aspergillus infection model and primary human neutrophils to probe how ZfpA affects A. fumigatus pathogenesis and response to antifungal drugs in vivo. ZfpA deletion promotes fungal clearance and attenuates virulence in wild-type hosts and this virulence defect is abrogated in neutrophil-deficient zebrafish. ZfpA deletion also increases susceptibility to human neutrophils ex vivo while overexpression impairs fungal killing. Overexpression of ZfpA confers protection against the antifungal caspofungin by increasing chitin synthesis during hyphal development, while ZfpA deletion reduces cell wall chitin and increases caspofungin susceptibility in neutrophil-deficient zebrafish. These findings suggest a protective role for ZfpA activity in resistance to the innate immune response and antifungal treatment during A. fumigatus infection.
Despite the challenges in treating glioblastomas (GBMs) with immune adjuvants, increasing evidence suggests that targeting the immune cells within the tumor microenvironment (TME) can lead to improved responses. Here, we present a closed-loop controlled, microbubble-enhanced focused ultrasound (MB-FUS) system and test its abilities to safely and effectively treat GBMs using immune checkpoint blockade. The proposed system can fine-tune the exposure settings to promote MB acoustic emission–dependent expression of the proinflammatory marker ICAM-1 and delivery of anti-PD1 in a mouse model of GBM. In addition to enhanced interaction of proinflammatory macrophages within the PD1-expressing TME and significant improvement in survival (P < 0.05), the combined treatment induced long-lived memory T cell formation within the brain that supported tumor rejection in rechallenge experiments. Collectively, our findings demonstrate the ability of MB-FUS to augment the therapeutic impact of immune checkpoint blockade in GBMs and reinforce the notion of spatially tumor-targeted (loco-regional) brain cancer immunotherapy.
by
Elizabeth A. Perkins;
Dawn Landis;
Zenoria L. Causey;
Yuanqing Edberg;
Richard J. Reynolds;
Laura B. Hughes;
Doyt L Conn;
Peter K. Gregersen;
Robert P. Kimberly;
Jeffrey C. Edberg;
S. Louis Bridges, Jr.
Objective:
We previously reported an analysis of single nucleotide polymorphisms (SNPs) in three validated European rheumatoid arthritis (RA) susceptibility loci, TAGAP, TNFAIP3, and CCR6 in African-Americans with RA. Unexpectedly, the disease-associated alleles were different in African-Americans than in Europeans. In an effort to better define their contribution, we performed additional SNP genotyping in these genes.
Methods:
Seven SNPs were genotyped in 446 African Americans with RA and 733 African American controls. Differences in minor allele frequency between cases and controls were analyzed after controlling for global proportion of European admixture, and pairwise linkage disequilibrium (LD) was estimated among the SNPs.
Results:
Three SNPs were significantly associated with RA: TNFAIP3 rs719149 A allele (OR (95% CI) 1.22 (1.03–1.44) (p =0.02); TAGAP rs1738074 G allele OR 0.75 (0.63–0.89), (p =0.0012); and TAGAP rs4709267 G allele 0.74 (0.60–0.91), (p =0.004). Pairwise LD between the TAGAP SNPs was low (R2=0.034). The haplotype containing minor alleles for both TAGAP SNPs was uncommon (4.5%). After conditional analysis on each TAGAP SNP, its counterpart remained significantly associated with RA (rs1738074 for rs4709267 p=0.00001; rs4709267 for rs1738074 p=0.00005), suggesting independent effects.
Conclusions:
SNPs in regulatory regions of TAGAP and an intronic SNP (TNFAIP3) are potential susceptibility loci in African Americans. Pairwise LD, haplotype analysis, and SNP conditioning analysis suggest that these two SNPs in TAGAP are independent susceptibility alleles. Additional fine mapping of this gene and functional genomic studies of these SNPs should provide additional insight into the role of these genes in RA.