Sustained Acoustic Medicine: A Novel Long Duration Approach to Biomodulation Utilizing Low Intensity Therapeutic Ultrasound

Therapeutic ultrasound is an established technique for biomodulation used by physical therapists. Typically it is used to deliver energy locally for the purpose of altering tissue plasticity and increasing local circulation. Access to ultrasound therapy has been limited by equipment and logistic requirements, which has reduced the overall efficacy of the therapy. Ultrasound miniaturization allows for development of portable, wearable, self-applied ultrasound devices that sidestep these limitations. Additionally, research has shown that the timescale of acoustic stimulation matters, and directly affects the quality of result. This paper describes a novel, long duration approach to therapeutic ultrasound and reviews the current data available for a variety of musculoskeletal conditions.

Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells

The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1 particles bound to target cells. Such markers should indicate how neutralizing and/or non-neutralizing antibodies might interdict infection by either blocking infection or sensitizing host cells for elimination by Fc-mediated effector function. Here we address this deficit by imaging fluorescently labeled CCR5-tropic HIV-1 pseudoviruses using confocal and superresolution microscopy to track the exposure of neutralizing and non-neutralizing epitopes as they appear on single HIV-1 particles bound to target cells. Epitope exposure was followed under conditions permissive or non-permissive for viral entry to delimit changes associated with virion binding from those associated with post-attachment events. We find that a previously unexpected array of gp120 epitopes is exposed rapidly upon target cell binding. This array comprises both neutralizing and non-neutralizing epitopes, the latter being hidden on free virions yet capable of serving as potent targets for Fc-mediated effector function. Under non-permissive conditions for viral entry, both neutralizing and non-neutralizing epitope exposures were relatively static over time for the majority of bound virions. Under entry-permissive conditions, epitope exposure patterns changed over time on subsets of virions that exhibited concurrent variations in virion contents. These studies reveal that bound virions are distinguished by a broad array of both neutralizing and non-neutralizing gp120 epitopes that potentially sensitize a freshly engaged target cell for destruction by Fc-mediated effector function and/or for direct neutralization at a post-binding step. The elucidation of these epitope exposure patterns during viral entry will help clarify antibody-mediated inhibition of HIV-1 as it is measured in vitro and in vivo.

A major strategy for blocking HIV-1 infection is to target antiviral antibodies or drugs to sites of vulnerability on the surface proteins of the virus. It is a relatively straightforward matter to explore these sites on the surfaces of free HIV-1 particles or on isolated viral envelope antigens. However, one difficulty presented by HIV-1 is that its surface proteins are flexible and change shape once the virus has attached to its host cell. To date, it has been difficult to predict how cell-bound HIV-1 exposes its sites of vulnerability. Yet the antiviral activities of certain antibodies indirectly suggest that there must be unique sites on cell-bound HIV-1 that are not found on free virus. Here, we use new techniques and tools to determine how HIV-1 exposes unique sites of vulnerability after attaching to host cells. We find that the virus exposes a remarkable array of these sites, including ones previously believed hidden. These exposure patterns explain the antiviral activities of various anti-HIV-1 antibodies and provide a new view of how HIV-1 might interact with the immune system. Our study also provides insights for how to target HIV-1 with antiviral antibodies, vaccines, or antiviral agents.

Ultrasonic modeling and hydrophone measurements of dual divergent transducers for wearable therapeutic ultrasound device

This paper models and experimentally measures the acoustic interference from two low intensity 3MHz continuous ultrasound transducers of the sam® wearable ultrasound device. Resulting data show that placement configuration, which dictates interference depth, and frequency phase variation are the main factors to acoustic pressure distribution. Mathematical analysis reveals that the acoustic pressure distribution from continuous ultrasound is modulated by near field variations at shallow tissue depths. This observation is useful in the application of sam® and in the further research of its therapeutic benefits.

HIV-1 CD4-induced (CD4i) gp120 epitope vaccines promote B and T-cell responses that contribute to reduced viral loads in rhesus macaques

To target the HIV CD4i envelope epitope, we primed rhesus macaques with replicating Ad-rhFLSC (HIV-1BaLgp120 linked to macaque CD4 D1 and D2), with or without Ad-SIVgag and Ad-SIVnef. Macaques were boosted with rhFLSC protein. Memory T-cells in PBMC, bronchoalveolar lavage and rectal tissue, antibodies with neutralizing and ADCC activity, and Env-specific secretory IgA in rectal secretions were elicited. Although protective neutralizing antibody levels were induced, SHIVSF162P4 acquisition following rectal challenge was not prevented. Rapid declines in serum ADCC activity, Env-specific memory B cells in PBMC and bone marrow, and systemic and mucosal memory T cells were observed immediately post-challenge together with delayed anamnestic responses. Innate immune signaling resulting from persisting Ad replication and the TLR-4 booster adjuvant may have been in conflict and reoriented adaptive immunity. A different adjuvant paired with replicating Ad, or a longer post-prime interval allowing vector clearance before boosting might foster persistent T- and B-cell memory.

Qualitative and quantitative variables that affect the potency of Fc- mediated effector function in vitro and in vivo: considerations for passive immunization using non-neutralizing antibodies

Passive immunization studies in non-human primates have established unequivocally that virus neutralization can prevent infection, providing the impetus for current intense efforts to identify immunogens that elicit broadly neutralizing antibodies in humans. Although Fc-mediated effector function may also contribute to protection by neutralizing antibodies, its role in protection by non-neutralizing antibodies is controversial. Here, I review the literature suggesting a role for Fc-mediated effector by non-neutralizing antibodies in protective immunity against HIV-1 with a primary focus on antibody mediated cellular cytotoxicity (ADCC) and related responses such as antibody-dependent cellular viral inhibition (ADCVI). Special emphasis is placed on qualitative and quantitative variables including antibody specificity and dose-response behavior in vitro and in vivo, which I propose as key variables in future passive immunization studies. Properly configured, these studies should clarify the role of Fc-mediated effector function by nonneutralizing antibodies in protection against HIV-1.

Role of Fc-mediated antibody function in protective immunity against HIV-1

The importance of Fc-mediated effector function in protective immunity to HIV-1 (hereafter referred to simply as HIV) is becoming increasingly apparent. A large of number of studies in natural infection cohorts, spanning the last 26 years, have associated Fc-mediated effector function, particularly antibody-dependent cellular cytotoxicity, with a favourable clinical course. These studies strongly suggest a role for Fc-mediated effector function in the post-infection control of viraemia. More recently, studies in both humans and non-human primates (NHPs) also implicate Fc-mediated effector function in blocking HIV acquisition. Accordingly, this review will discuss the results supporting a role of Fc-mediated effector function in both blocking acquisition and post-infection control of viraemia. Parallel studies in NHPs and humans will be compared for common themes. Context for this discussion will be provided by summarizing the temporal emergence of key host and virological events over the course of an untreated HIV infection framing where, when and how Fc-mediated effector function might be protective. A hypothesis that Fc-mediated effector function protects primarily in the early stages of both acquisition and post-infection control of viraemia will be developed.

Pilot Clinical Studies of Long Duration, Low Intensity Therapeutic Ultrasound for Osteoarthritis

Osteoarthritis is one of the leading causes of disability in the aging population. Long duration, low intensity therapeutic ultrasound has had promising impact in animal models to slow the progression of the disease and provide joint relief. Two pilot studies were conducted using a novel, wearable platform for delivering ultrasound to evaluate the potential clinical benefits of ultrasound therapy on knee osteoarthritis. There was a pain reduction effect from using ultrasound, as high as fifty two percent in one study. As well, initial data demonstrates that mobility may be increased for patients experiencing mild to moderate arthritis of the knee.

Elevated suppressor of cytokine signaling-1 (SOCS-1): a mechanism for dysregulated osteoclastogenesis in HIV transgenic rats

Accelerated bone loss leading to osteopenia, osteoporosis, and bone fracture is a major health problem that is increasingly common in human immunodeficiency virus (HIV)-infected patients. The underlying pathogenesis is unclear but occurs in both treatment naïve and individuals receiving antiretroviral therapies. We developed an HIV-1 transgenic rat that exhibits many key features of HIV disease including HIV-1-induced changes in bone mineral density (BMD). A key determinant in the rate of bone loss is the differentiation of osteoclasts, the cells responsible for bone resorption. We found HIV-1 transgenic osteoclast precursors (OCP) express higher levels of suppressor of cytokine signaling-1 (SOCS-1) and TNF receptor-associated factor 6 (TRAF6) and are resistant to interferon-gamma (IFN-γ) mediated suppression of osteoclast differentiation. Our data suggest that dysregulated SOCS-1 expression by HIV-1 transgenic OCP promotes osteoclastogenesis leading to the accelerated bone loss observed in this animal model. We propose that elevated SOCS-1 expression in OCP antagonizes the inhibitory effects of IFN-γ and enhances receptor activator of NF-kB ligand (RANKL) signaling that drives osteoclast differentiation and activation. Understanding the molecular mechanisms of HIV-associated BMD changes has the potential to detect and treat bone metabolism disturbances early and improve the quality of life in patients.

Live-attenuatedSalmonellaas a prototype vaccine vector for passenger immunogens in humans: are we there yet?

It has been nearly 20 years since the first Phase I clinical trial of a live-attenuated bacterial vaccine was created by recombinant DNA methods, opening the door to the use of these organisms as mucosal delivery vehicles for passenger antigens. Over this time, a number of animal studies have indicated the feasibility of this approach. These include studies showing that bacteria can deliver antigens expressed by the bacterium itself and that bacteria can deliver DNA vaccines to be expressed in target eukaryotic cells. Concomitant studies have identified a number of attenuating mutations that render the bacterial vectors both safe and immunogenic in humans. Both avenues of research indicate the significant promise of this approach to mucosal vaccine development; however, this promise remains largely unrealized at the level of human clinical trials. This review sketches the history of this problem and points toward possible solutions using Salmonella vaccine vectors as the prototypes.

Human Factors Engineering and testing for a wearable, long duration ultrasound system self-applied by an end user

One of the major challenges in the design of a new class of medical device is ensuring that the device will have a safe and effective user interface for the intended users. Human Factors Engineering addresses these concerns through direct study of how a user interacts with newly designed devices with unique features. In this study, a novel long duration, low intensity therapeutic ultrasound device is tested by 20 end users representative of the intended user population. Over 90% of users were able to operate the device successfully. The therapeutic ultrasound device was found to be reasonably safe and effective for the intended users, uses, and use environments.

Allosteric induction of the CD4-bound conformation of HIV-1 Gp120

BACKGROUND

HIV-1 infection of target cells is mediated via the binding of the viral envelope protein, gp120, to the cell surface receptor CD4. This interaction leads to conformational rearrangements in gp120 forming or revealing CD4 induced (CD4i) epitopes which are critical for the subsequent recognition of the co-receptor required for viral entry. The CD4-bound state of gp120 has been considered a potential immunogen for HIV-1 vaccine development. Here we report on an alternative means to induce gp120 into the CD4i conformation.

RESULTS

Combinatorial phage display peptide libraries were screened against HIV-1 gp120 and short (14aa) peptides were selected that bind the viral envelope and allosterically induce the CD4i conformation. The lead peptide was subsequently systematically optimized for higher affinity as well as more efficient inductive activity. The peptide:gp120 complex was scrutinized with a panel of neutralizing anti-gp120 monoclonal antibodies and CD4 itself, illustrating that peptide binding does not interfere with or obscure the CD4 binding site.

CONCLUSIONS

Two surfaces of gp120 are considered targets for the development of cross neutralizing antibodies against HIV-1; the CD4 binding site and CD4i epitopes. By implementing novel peptides that allosterically induce the CD4i epitopes we have generated a viral envelope that presents both of these surfaces simultaneously.

Design and evaluation of a wearable self-applied therapeutic ultrasound device for chronic myofascial pain

Ultrasound therapy for pain and healing is a versatile treatment modality for musculoskeletal conditions that is used daily in rehabilitation clinics around the world. Our group designed and constructed a wearable, battery-operated, low-intensity therapeutic ultrasound (LITUS) device that patients could self-apply and operate during daily activity for up to 6 h. Thirty patients with chronic trapezius myofascial pain evaluated the LITUS system in a double-blind, placebo-controlled, 10-d study under institutional review board approval. While continuing their prescribed medication regimen, patients with the active device reported on average 1.94× reduction in pain and 1.58× improvement in health relative to placebo devices after 1 h of treatment. Both of these results were statistically significant (p < 0.05) for the first 2 d of the study. Male patients reported the majority of benefit, and there is a sex-treatment confound in the sample. The study indicates that wearable, long-duration LITUS technology improves mobile access to drug-free pain relief.

Ultrasound-assisted convection-enhanced delivery to the brain in vivo with a novel transducer cannula assembly: laboratory investigation

OBJECT

In convection-enhanced delivery (CED), drugs are infused locally into tissue through a cannula inserted into the brain parenchyma to enhance drug penetration over diffusion strategies. The purpose of this study was to demonstrate the feasibility of ultrasound-assisted CED (UCED) in the rodent brain in vivo using a novel, low-profile transducer cannula assembly (TCA) and portable, pocket-sized ultrasound system.

METHODS

Forty Sprague-Dawley rats (350-450 g) were divided into 2 equal groups (Groups 1 and 2). Each group was divided again into 4 subgroups (n = 5 in each). The caudate of each rodent brain was infused with 0.25 wt% Evans blue dye (EBD) in phosphate-buffered saline at 2 different infusion rates of 0.25 μl/minute (Group 1), and 0.5 μl/minute (Group 2). The infusion rates were increased slowly over 10 minutes from 0.05 to 0.25 μl/minute (Group 1) and from 0.1 to 0.5 μl/minute (Group 2). The final flow rate was maintained for 20 minutes. Rodents in the 4 control subgroups were infused using the TCA without ultrasound and without and with microbubbles added to the infusate (CED and CED + MB, respectively). Rodents in the 4 UCED subgroups were infused without and with microbubbles added to the infusate (UCED and UCED + MB) using the TCA with continuous-wave 1.34-MHz low-intensity ultrasound at a total acoustic power of 0.11 ± 0.005 W and peak spatial intensity at the cannula tip of 49.7 mW/cm(2). An additional 4 Sprague-Dawley rats (350-450 g) received UCED at 4 different and higher ultrasound intensities at the cannula tip ranging from 62.0 to 155.0 mW/cm(2) for 30 minutes. The 3D infusion distribution was reconstructed using MATLAB analysis. Tissue damage and morphological changes to the brain were assessed using H & E.

RESULTS

The application of ultrasound during infusion (UCED and UCED + MB) improved the volumetric distribution of EBD in the brain by a factor of 2.24 to 3.25 when there were no microbubbles in the infusate and by a factor of 1.16 to 1.70 when microbubbles were added to the infusate (p < 0.001). On gross and histological examination, no damage to the brain tissue was found for any acoustic exposure applied to the brain.

CONCLUSIONS

The TCA and ultrasound device show promise to improve the distribution of infused compounds during CED. The results suggest further studies are required to optimize infusion and acoustic parameters for small compounds and for larger molecular weight compounds that are representative of promising antitumor agents. In addition, safe levels of ultrasound exposure in chronic experiments must be determined for practical clinical evaluation of UCED. Extension of these experiments to larger animal models is warranted to demonstrate efficacy of this technique.

[Identification of Env-specific monoclonal antibodies from Chinese HIV-1 infected person by B cell activation and RT-PCR cloning]

To obtain protective human monoclonal antibody from HIV-1 infected person, we adapted a technology for isolating antigen specific monoclonal antibody from human memory B cells through in vitro B cell activation coupled with RT-PCT and expression cloning. Human B cells were purified by negative sorting from PBMCs of HIV-1 infected individuals and memory B cells were further enriched using anti-CD27 microbeads. Two hundred memory B cells per well were cultured in 96-well round-bottom plates Env-specific antibodies in supernatants were with feeder cells in medium containing EBV and CpG. screened by ELISA after 1-2 weeks' culture. Cells from positive wells of Env-specific antibody were harvested and total RNA was isolated. Human VH and Vkappa or Vlambda genes were amplified by RT-PCR and cloned into IgG1 and kappa or lambda expressing vectors. Functional VH and Vkappa or Vlambda were identified by cotransfecting 293T cells with individual heavy chain and light chain clones followed by analysis of culture supernatants by ELISA for Env-specific antibodies. Finally, corresponding mAb was produced by transient transfection of 293T cells with the identified VH and Vkappa/lambda pair and purified by protein A affinity chromatography. Purified monocolonal antibodies were used for HIV-1 specific antibody-dependent cell-mediated cytotoxicity (ADCC) and neutralizing activity assay. Four monocolonal Env-specific antibodies were isolated from one HIV-1 subtype B' infected individual. Two of them showed strong ADCC activity and one showed weak neutralizing activity against HIV-1. Its further studies on their application in therapeutic or prophylactic vaccines against HIV-1 should be grounded.

Immune-correlates analysis of an HIV-1 vaccine efficacy trial

BACKGROUND

In the RV144 trial, the estimated efficacy of a vaccine regimen against human immunodeficiency virus type 1 (HIV-1) was 31.2%. We performed a case-control analysis to identify antibody and cellular immune correlates of infection risk.

METHODS

In pilot studies conducted with RV144 blood samples, 17 antibody or cellular assays met prespecified criteria, of which 6 were chosen for primary analysis to determine the roles of T-cell, IgG antibody, and IgA antibody responses in the modulation of infection risk. Assays were performed on samples from 41 vaccinees who became infected and 205 uninfected vaccinees, obtained 2 weeks after final immunization, to evaluate whether immune-response variables predicted HIV-1 infection through 42 months of follow-up.

RESULTS

Of six primary variables, two correlated significantly with infection risk: the binding of IgG antibodies to variable regions 1 and 2 (V1V2) of HIV-1 envelope proteins (Env) correlated inversely with the rate of HIV-1 infection (estimated odds ratio, 0.57 per 1-SD increase; P=0.02; q=0.08), and the binding of plasma IgA antibodies to Env correlated directly with the rate of infection (estimated odds ratio, 1.54 per 1-SD increase; P=0.03; q=0.08). Neither low levels of V1V2 antibodies nor high levels of Env-specific IgA antibodies were associated with higher rates of infection than were found in the placebo group. Secondary analyses suggested that Env-specific IgA antibodies may mitigate the effects of potentially protective antibodies.

CONCLUSIONS

This immune-correlates study generated the hypotheses that V1V2 antibodies may have contributed to protection against HIV-1 infection, whereas high levels of Env-specific IgA antibodies may have mitigated the effects of protective antibodies. Vaccines that are designed to induce higher levels of V1V2 antibodies and lower levels of Env-specific IgA antibodies than are induced by the RV144 vaccine may have improved efficacy against HIV-1 infection.

Correlation between circulating HIV-1 RNA and broad HIV-1 neutralizing antibody activity

OBJECTIVE

To examine the relationship between HIV-1 antigenic load (plasma RNA copies/mL) and broad HIV-1 neutralizing antibody activity.

METHODS

Plasma from 120 HIV-1-infected patients, including HIV-1 natural viral suppressors (similar to elite controllers), was tested for neutralization against 15 Tier 1/Tier 2 HIV-1 pseudoviruses. Broad HIV-1 neutralizing antibody activity was confirmed with immunoglobulin G and heterlogous clade testing (18 pseudoviruses from Clades A, C, and CRF02_AG). Statistical analysis was performed to determine factors associated with broad HIV-1 neutralizing antibody activity.

RESULTS

Ten individuals with broad HIV-1 neutralizing antibody activity were identified. These individuals had a median CD4 count of 589 cells per microliter (range 202-927), 1611 HIV-1 RNA copies per milliliter (range 110-8964), and 13 years since HIV diagnosis (range 1-22). There was a significant correlation between the presence of broadly neutralizing antibodies in those with HIV-1 RNA between 100 and 10,000 copies per milliliter compared with those <100 or >10,000 copies per milliliter (P = 0.0003 and 0.0245, respectively). Individuals with HIV-1 RNA 100-10,000 copies per milliliter had a higher number of Tier 2 viruses neutralized compared with the <100 or >10,000 copies per milliliter groups (P ≤ 0.0001 and P = 0.076, respectively). Male sex was associated with broad HIV-1 neutralizing antibody activity (P = 0.016).

CONCLUSIONS

These results indicate that low but persistent HIV antigen expression correlates with broad HIV-1 neutralizing antibody activity. At higher levels of plasma viremia, neutralization titers were diminished. Conversely, at lower levels, there seems to be insufficient antigen stimulation to maintain high neutralization titers. These findings may have important implications in furthering the understanding of the humoral response to HIV infection.

A portable high-intensity focused ultrasound device for noninvasive venous ablation

BACKGROUND

Varicose veins and other vascular abnormalities are common clinical entities. Treatment options include vein stripping, sclerotherapy, and endovenous laser treatment, but all involve some degree of invasive intervention. The purpose of this study was to determine ex vivo the effectiveness of a novel hand-held, battery-operated, high-intensity focused ultrasound (HIFU) device for transcutaneous venous ablation.

METHODS

The ultrasound device is 14 x 9 x 4 cm, weighs 650 g, and is powered by 4 lithium ion battery packs. An ex vivo testing platform consisting of two different models comprised of sequentially layered skin-muscle-vein or skin-fat-vein was developed, and specimens were treated with HIFU. The tissues were then disassembled, imaged, and processed for histology. The luminal cross-sectional area of vein that had been treated with HIFU and nontreated controls were measured, and the values presented as median and interquartile range (IQR). The values were compared using a Wilcoxon rank-sum test, and statistical significance was set at P < .05.

RESULTS

On gross and histologic examination, veins that had been treated with HIFU showed evidence of coagulation necrosis. The surface of the muscle in direct contact with the vein had a pinpoint area of coagulation, whereas the adjacent fat appeared undisturbed; the skin, fat, and the surface of the muscle in contact with the transducer remained completely unaffected. The cross-sectional area was 3.79 mm(2) (IQR, 3.38-4.22) of the control vein lumen and 0.16 mm(2) (IQR, 0.04-0.39) in those that had been treated with HIFU (P = .0304).

CONCLUSION

This inexpensive, portable HIFU device has the potential to allow clinicians to easily perform venous ablation in a manner that is entirely noninvasive and without the expense or inconvenience of large, complicated devices. This device represents a significant step forward in the development of new applications for HIFU technology.