High-density lipoprotein cholesterol efflux capacity (CEC) is inversely associated with incident cardiovascular events, independent of high-density lipoprotein cholesterol. Obesity is often ...characterized by impaired high-density lipoprotein function. However, the effects of different bariatric surgical techniques on CEC have not been compared. This study sought to determine the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on CEC.
We prospectively studied severely obese, nondiabetic, premenopausal Hispanic women not using lipid medications undergoing RYGB (n=31) or SG (n=36). Subjects were examined before and at 6 and 12 months after surgery. There were no differences in baseline characteristics between surgical groups. Preoperative CEC correlated most strongly with Apo A1 (apolipoprotein A1) concentration but did not correlate with body mass index, waist:hip, high-sensitivity C-reactive protein, or measures of insulin resistance. After 6 months, SG produced superior response in high-density lipoprotein cholesterol and Apo A1 quantity, as well as global and non-ABCA1 (ATP-binding cassette transporter A1)-mediated CEC (
=0.048,
=0.018, respectively) versus RYGB. In multivariable regression models, only procedure type was predictive of changes in CEC (
=0.05). At 12 months after SG, CEC was equivalent to that of normal body mass index control subjects, whereas it remained impaired after RYGB.
SG and RYGB produce similar weight loss, but contrasting effects on CEC. These findings may be relevant in discussions about the type of procedure that is most appropriate for a particular obese patient. Further study of the mechanisms underlying these changes may lead to improved understanding of the factors governing CEC and potential therapeutic interventions to maximally reduce cardiovascular disease risk in both obese and nonobese patients.
There is a need to develop improved methods to treat and potentially cure HIV infection. During chronic HIV infection, replication is concentrated within T follicular helper cells (Tfh) located ...within B cell follicles, where low levels of virus-specific CTL permit ongoing viral replication. We previously showed that elevated levels of simian immunodeficiency virus (SIV)-specific CTL in B cell follicles are linked to both decreased levels of viral replication in follicles and decreased plasma viral loads. These findings provide the rationale to develop a strategy for targeting follicular viral-producing (Tfh) cells using antiviral chimeric antigen receptor (CAR) T cells co-expressing the follicular homing chemokine receptor CXCR5. We hypothesize that antiviral CAR/CXCR5-expressing T cells, when infused into an SIV-infected animal or an HIV-infected individual, will home to B cell follicles, suppress viral replication, and lead to long-term durable remission of SIV and HIV. To begin to test this hypothesis, we engineered gammaretroviral transduction vectors for co-expression of a bispecific anti-SIV CAR and rhesus macaque CXCR5. Viral suppression by CAR/CXCR5-transduced T cells was measured
, and CXCR5-mediated migration was evaluated using both an
transwell migration assay, as well as a novel
tissue migration assay. The functionality of the CAR/CXCR5 T cells was demonstrated through their potent suppression of SIV
and SIV
replication in
and migration to the ligand CXCL13
, and concentration in B cell follicles in tissues
. These novel antiviral immunotherapy products have the potential to provide long-term durable remission (functional cure) of HIV and SIV infections.
Adoptive transfer of CD8 T cells genetically engineered to express "chimeric antigen receptors" (CARs) represents a potential approach toward an HIV infection "functional cure" whereby durable ...virologic suppression is sustained after discontinuation of antiretroviral therapy. We describe a novel bispecific CAR in which a CD4 segment is linked to a single-chain variable fragment of the 17b human monoclonal antibody recognizing a highly conserved CD4-induced epitope on gp120 involved in coreceptor binding. We compared a standard CD4 CAR with CD4-17b CARs where the polypeptide linker between the CD4 and 17b moieties is sufficiently long (CD4-35-17b CAR) versus too short (CD4-10-17b) to permit simultaneous binding of the two moieties to a single gp120 subunit. When transduced into a peripheral blood mononuclear cell (PBMC) or T cells thereof, all three CD4-based CARs displayed specific functional activities against HIV-1 Env-expressing target cells, including stimulation of gamma interferon (IFN-γ) release, specific target cell killing, and suppression of HIV-1 pseudovirus production. In assays of spreading infection of PBMCs with genetically diverse HIV-1 primary isolates, the CD4-10-17b CAR displayed enhanced potency compared to the CD4 CAR whereas the CD4-35-17b CAR displayed diminished potency. Importantly, both CD4-17b CARs were devoid of a major undesired activity observed with the CD4 CAR, namely, rendering the transduced CD8(+) T cells susceptible to HIV-1 infection. Likely mechanisms for the superior potency of the CD4-10-17b CAR over the CD4-35-17b CAR include the greater potential of the former to engage in the serial antigen binding required for efficient T cell activation and the ability of two CD4-10-17b molecules to simultaneously bind a single gp120 subunit.
HIV research has been energized by prospects for a cure for HIV infection or, at least, for a "functional cure" whereby antiretroviral therapy can be discontinued without virus rebound. This report describes a novel CD4-based "chimeric antigen receptor" (CAR) which, when genetically engineered into T cells, gives them the capability to selectively respond to and kill HIV-infected cells. This CAR displays enhanced features compared to previously described CD4-based CARs, namely, increased potency and avoidance of the undesired rendering of the genetically modified CD8 T cells susceptible to HIV infection. When adoptively transferred back to the individual, the genetically modified T cells will hopefully provide durable killing of infected cells and sustained virus suppression without continued antiretroviral therapy, i.e., a functional cure.
B lymphocytes are the major cellular reservoir in individuals infected with Kaposi's sarcoma-associated herpesvirus (KSHV), and the virus is etiologically linked to two B cell lymphoproliferative ...disorders. We previously described the MC116 human B cell line as a KSHV-susceptible model to overcome the paradoxical refractoriness of B cell lines to experimental KSHV infection. Here, using monoclonal antibody inhibition and a deletion mutant virus, we demonstrate that the KSHV virion glycoprotein K8.1A is critical for infection of MC116, as well as tonsillar B cells; in contrast, we confirm previous reports on the dispensability of the glycoprotein for infection of primary endothelial cells and other commonly studied non-B cell targets. Surprisingly, we found that the role of K8.1A in B cell infection is independent of its only known biochemical activity of binding to surface heparan sulfate, suggesting the possible involvement of an additional molecular interaction(s). Our finding that K8.1A is a critical determinant for KSHV B cell tropism parallels the importance of proteins encoded by positionally homologous genes for the cell tropism of other gammaherpesviruses.
Elucidating the molecular mechanisms by which KSHV infects B lymphocytes is critical for understanding how the virus establishes lifelong persistence in infected people, in whom it can cause life-threatening B cell lymphoproliferative disease. Here, we show that K8.1A, a KSHV-encoded glycoprotein on the surfaces of the virus particles, is critical for infection of B cells. This finding stands in marked contrast to previous studies with non-B lymphoid cell types, for which K8.1A is known to be dispensable. We also show that the required function of K8.1A in B cell infection does not involve its binding to cell surface heparan sulfate, the only known biochemical activity of the glycoprotein. The discovery of this critical role of K8.1A in KSHV B cell tropism opens promising new avenues to unravel the complex mechanisms underlying infection and disease caused by this viral human pathogen.
Within the trimeric HIV-1 envelope (Env) spike, the first and second variable loops (V1V2 region) and the third variable loop (V3) of the gp120 subunit play dual roles in antibody recognition, ...because they contain neutralization epitopes and also participate in epitope masking. The spatial relationships between V1V2 and V3 and the associated mechanisms of epitope masking remain unclear. Here we investigated interactions between these domains using two monoclonal antibodies recognizing distinct conserved linear epitopes that are subject to masking in the functional trimer, which limits their neutralizing activities. Using Env pseudotype virus infection assays, we found that deleting the V1V2 region greatly enhanced neutralization by both antibodies, leading us to consider two alternative models: V1V2 on one gp120 protomer masks V3 on the same protomer (intraprotomer or cis masking) versus on an adjacent protomer (interprotomer or trans masking). Our experimental approach exploited a previously described complementation system wherein two variant Envs harboring different inactivating mutations (one in gp120, the other in gp41) are coexpressed in the same cell; functional Env results only from cooperative interactions within mixed trimers, thereby enabling selective examination of mixed trimer activity. We introduced additional mutations that either promoted (V1V2 deletion, i.e., unmasking) or prevented (GPGR to GPGQ mutation, i.e., epitope destruction) interaction with the antibodies. The observed neutralization sensitivities of mixed trimers produced from various combinations of constructs support the intraprotomer (cis) model of V1V2 masking of V3 epitopes.
Psoriasis is associated with increased cardiovascular risk that is not captured by traditional proinflammatory biomarkers.
To investigate the relationship between Psoriasis Area and Severity Index, ...circulating proinflammatory biomarkers, and vascular health in psoriasis.
In patients with psoriasis and in age and sex-matched controls, 273 proteins were analyzed with the Proseek Multiplex Cardiovascular disease reagents kit and Inflammatory reagents kit (Olink Bioscience), whereas vascular endothelial inflammation and health were measured via direct transcriptomic analysis of brachial vein endothelial cells.
In psoriasis, chemokine ligand 20 (CCL20), interleukin (IL) 6, and IL-17A were the top 3 circulating proinflammatory cytokines. Vascular endothelial inflammation correlated with CCL20 (r = 0.55; P < .001) and less so with IL-6 (r = 0.36; P = .04) and IL-17A (r = 0.29; P = .12). After adjustment for potential confounders, the association between CCL20 and vascular endothelial inflammation remained significant (β = 1.71; P = .02). In nested models, CCL20 added value (χ2 = 79.22; P < .001) to a model already incorporating the Psoriasis Area and Severity Index, Framingham risk, high-sensitivity C-reactive protein, Il-17A, and IL-6 (χ2 = 48.18; P < .001) in predicting vascular endothelial inflammation.
Our study was observational and did not allow for causal inference in the relationship between CCL20 and cardiovascular risk.
We demonstrate that CCL20 expression has a strong association with vascular endothelial inflammation, reflects systemic inflammation, and may serve as a potential biomarker of impaired vascular health in psoriasis.
Mechanisms explaining the relationship between obesity and cardiovascular disease (CVD) are needed. Despite growing recognition of the importance of the anucleate platelet transcriptome, low levels ...of RNA in platelets make assessment difficult. We sought to perform unbiased platelet RNA profiling in obesity by performing a prospective study of severe obesity and weight loss via bariatric surgery on platelet characteristics and mRNA profile in 26 pre-menopausal, non-diabetic women (31.6 ± 8.4 years; BMI 43.0 ± 6.5 kg/m
2
) who underwent sleeve gastrectomy. Totally, 10 women of similar age with normal BMI served as controls. Platelet activation via flow cytometry was assessed before and after surgery. RNA-sequencing (RNAseq) was performed on platelet isolates from a subset of 13 subjects (eight obese women and five normal-BMI subjects). Platelet count, size, and age did not differ between control and obese women. However, platelet surface P-selectin and CD40 were higher in obesity. RNAseq demonstrated 629 differentially abundant transcripts in obesity. Notably, S100A9 and AGER, established markers of cardiovascular risk, were two of the most highly upregulated transcripts (each > 2.5 fold). At 6 months post-operatively, subjects lost 26.1 ± 5.8% body weight and inducible platelet P-selectin expression was reduced. Expression of 170 transcripts was affected by surgery, but only a small fraction (46/629) were genes found altered in obesity. We demonstrate that obesity is associated with an altered platelet transcriptome and increased platelet activation, which is partly attenuated by bariatric surgery. These observations suggest that platelets may contribute to increased cardiovascular risk in obesity through a variety of mechanisms.
T cells expressing a simian immunodeficiency (SIV)-specific chimeric antigen receptor (CAR) and the follicular homing molecule, CXCR5, were infused into antiretroviral therapy (ART) suppressed, ...SIV-infected rhesus macaques to assess their ability to localize to the lymphoid follicle and control the virus upon ART interruption. While the cells showed evidence of functionality, they failed to persist in the animals beyond 28 days. Development of anti-CAR antibodies could be responsible for the lack of persistence. Potential antigenic sites on the anti-SIV CAR used in these studies included domains 1 and 2 of CD4, the carbohydrate recognition domain (CRD) of mannose-binding lectin (MBL), and an extracellular domain of the costimulatory molecule, CD28, along with short linker sequences. Using a flow cytometry based assay and target cells expressing the CAR/CXCR5 construct, we examined the serum of the CD4-MBL CAR/CXCR5-T cell treated animals to determine that the animals had developed an anti-CAR antibody response after infusion. Binding sites for the anti-CAR antibodies were identified by using alternative CARs transduced into target cells and by preincubation of the target cells with a CD4 blocking antibody. All of the treated animals developed antibodies in their serum that bound to CD4-MBL CAR/CXCR5 T cells and the majority were capable of inducing an ADCC response. The CD4 antibody-blocking assay suggests that the dominant immunogenic components of this CAR are the CD4 domains with a possible additional site of the CD28 domain with its linker. This study shows that an anti-drug antibody (ADA) response can occur even when using self-proteins, likely due to novel epitopes created by abridged self-proteins and/or the self-domain of the CAR connection to a small non-self linker. While in our study, there was no statistically significant correlation between the ADA response and the persistence of the CD4-MBL CAR/CXCR5-T cells in rhesus macaques, these findings suggest that the development of an ADA response could impact the long-term persistence of self-based CAR immunotherapies.
In addition to CD4, the human immunodeficiency virus (HIV) requires a
coreceptor for entry into target cells. The chemokine receptors CXCR4 and CCR5,
members of the G protein-coupled receptor ...superfamily, have been identified as
the principal coreceptors for T cell line-tropic and macrophage-tropic HIV-1
isolates, respectively. The updated coreceptor repertoire includes numerous
members, mostly chemokine receptors and related orphans. These discoveries
provide a new framework for understanding critical features of the basic
biology of HIV-1, including the selective tropism of individual viral variants
for different CD4
+
target cells and the membrane fusion
mechanism governing virus entry. The coreceptors also provide molecular
perspectives on central puzzles of HIV-1 disease, including the selective
transmission of macrophage-tropic variants, the appearance of T cell
line-tropic variants in many infected persons during progression to AIDS, and
differing susceptibilities of individuals to infection and disease progression.
Genetic findings have yielded major insights into the in vivo roles of
individual coreceptors and their ligands; of particular importance is the
discovery of an inactivating mutation in the CCR5 gene which, in homozygous
form, confers strong resistance to HIV-1 infection. Beyond providing new
perspectives on fundamental aspects of HIV-1 transmission and pathogenesis, the
coreceptors suggest new avenues for developing novel therapeutic and
preventative strategies to combat the AIDS epidemic.
Psychological stress (PS) is associated with systemic inflammation and accelerates inflammatory disease progression (e.g., atherosclerosis). The mechanisms underlying stress-mediated inflammation and ...future health risk are poorly understood. Monocytes are key in sustaining systemic inflammation, and recent studies demonstrate that they maintain the memory of inflammatory insults, leading to a heightened inflammatory response upon rechallenge. We show that PS induces remodeling of the chromatin landscape and transcriptomic reprogramming of monocytes, skewing them to a primed hyperinflammatory phenotype. Monocytes from stressed mice and humans exhibit a characteristic inflammatory transcriptomic signature and are hyperresponsive upon stimulation with Toll-like receptor ligands. RNA and ATAC sequencing reveal that monocytes from stressed mice and humans exhibit activation of metabolic pathways (mTOR and PI3K) and reduced chromatin accessibility at mitochondrial respiration-associated loci. Collectively, our findings suggest that PS primes the reprogramming of myeloid cells to a hyperresponsive inflammatory state, which may explain how PS confers inflammatory disease risk.
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•Psychological stress reprograms monocytes to a hyperinflammatory primed phenotype•Stress-mediated priming activates transcriptomic and metabolic pathways in monocytes•Stress-mediated priming alters inflammatory responses in mice and humans
Barrett et al. investigate the impact of psychological stress on monocytes. They report that psychological stress remodels the chromatin landscape of monocytes and the myeloid transcriptome, with stress-mediated changes skewing monocytes to a primed-hyperinflammatory phenotype. This study provides mechanistic insight into how psychological stress confers risk to inflammation-based disorders.
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