Targeting glycosylated antigens on cancer cells using siglec-7/9-based CAR T-cells

Chimeric antigen receptor (CAR) T-cells treatment demonstrate the increasing and powerful potential of immunotherapeutic strategies, as seen mainly for hematological malignancies. Still, efficient CAR-T cell approaches for the treatment of a broader spectrum of tumors are needed. It has been shown that cancer cells can implement strategies to evade immune response that include the expression of inhibitory ligands, such as hypersialylated proteins (sialoglycans) on their surface. These may be recognized by sialic acid-binding immunoglobulin-type lectins (siglecs) which are surface receptors found primarily on immune cells. In this regard, siglec-7 and -9 are found on immune cells, such as natural killer cells, T-cells, and dendritic cells and they can promote immune suppression when binding to sialic acids expressed on target cells. In the present study, we hypothesized that it is possible to use genetically engineered T-cells expressing siglec-based CARs, enabling them to recognize and eliminate tumor cells, in a non-histocompatibility complex molecule restricted way. Thus, we genetically modified human T-cells with different chimeric receptors based on the exodomain of human siglec-7 and -9 molecules and selected optimal receptors. We then assessed their antitumor activity in vitro demonstrating the recognition of cell lines from different histologies. These results were confirmed in a tumor xenograft model exemplifying the potential of the present approach. Overall, this study demonstrates the benefit of targeting cancer-associated glycosylation patterns using CAR based on native immune receptors and expressed in human primary T-cells.     

An analytical formulation of the law of intersegmental coordination during human locomotion

The law of intersegmental coordination is a kinematic law that describes the coordination patterns among the elevation angles of the lower limb segments during locomotion (Borghese et al. in J Physiol 494:863–879, 1996). This coordination pattern reduces the number of degrees of freedom of the lower limb to two, i.e. the elevation angles covary along a plane in angular space. The properties of the plane that constrains the time course of the elevation angles have been extensively studied, and its orientation was found to be correlated with gait velocity and energy expenditure (Bianchi et al. in J Neurophysiol 79:2155–2170, 1998). Here, we present a mathematical model that represents the rotations of the elevation angles in terms of simple oscillators with appropriate phase shifts between them. The model explains what requirements the time courses of the elevation angles must fulfill in order for the angular covariation relationship to be planar. Moreover, an analytical formulation is proposed for both the orientation of the plane and for the eccentricity of the nearly elliptical shape that is generated within this plane, in terms of the amplitudes and relative phases of the first harmonics of the segments elevation angles. The model presented here sheds some new light on the possible interactions among the Central Pattern Generators possibly underlying the control of biped locomotion. The model precisely specifies how any two segments in the limb interact, and how a change in gait velocity affects the orientation of the intersegmental coordination plane mainly through a change in phase shifts between the segments. Implications of this study with respect to neural control of locomotion and other motor activities are discussed. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Competitive quenching: a possible novel approach in protecting RPE cells from damage during PDT

PURPOSE: The purpose of this study is to demonstrate feasibility of using our novel concept, termed competitive quenching, for protecting the choroidal extravascular compartment and retinal pigment epithelium (RPE) from verteporfin (VP)-induced phototoxicity using hypericin. Furthermore, we aim to achieve partitioning of the quencher, hypericin, in the extravascular space and VP within the microvascular compartment of the chorio-retinal complex in vivo. METHODS: We protect RPE cells from damage inflicted by photoactivated VP by introducing hypericin into these cells prior to photosensitization to quench the photosensitizing activity of VP. Cell protection levels were measured by MTT and Hemacolor viability assays. Wavelength range used for VP photoexcitation (700 +/- 40 nm) excludes the absorption range of hypericin, preventing the latter from photoactivation. Pharmacokinetic conditions, in which hypericin spreads throughout the choroidal and retinal extravascular space while VP is confined to the vasculature, are delineated using double-fluorescence imaging. RESULTS: Cell viability increased 3- to 5-fold when 10-20 microM hypericin were present in RPE cells during photosensitization with 0.1-0.5 microM VP. VP fluorescence intensity was unchanged by the presence of hypericin in the cells. Hypericin administered intravenously to rats was confined to the choroidal vasculature after 15 min to 2 hr. Subsequently, hypericin partitioned to the choroidal and retinal extravascular space. VP administered at this time was confined to the microvasculature. CONCLUSIONS: RPE and choroid may potentially be protected by compartmentalizing hypericin to the extravascular compartment while VP administered shortly before photosensitization is confined to the microvasculature. Adverse photodynamic therapy (PDT) damage to choroidal tissues adjacent to neovasculature targeted for photoablation have the potential of being prevented by competitive quenching with hypericin.     

Effective prevention of microbial biofilm formation on medical devices by low-energy surface acoustic waves

Low-energy surface acoustic waves generated from electrically activated piezo elements are shown to effectively prevent microbial biofilm formation on indwelling medical devices. The development of biofilms by four different bacteria and Candida species is prevented when such elastic waves with amplitudes in the nanometer range are applied. Acoustic-wave-activated Foley catheters have all their surfaces vibrating with longitudinal and transversal dispersion vectors homogeneously surrounding the catheter surfaces. The acoustic waves at the surface are repulsive to bacteria and interfere with the docking and attachment of planktonic microorganisms to solid surfaces that constitute the initial phases of microbial biofilm development. FimH-mediated adhesion of uropathogenic Escherichia coli to guinea pig erythrocytes was prevented at power densities below thresholds that activate bacterial force sensor mechanisms. Elevated power densities dramatically enhanced red blood cell aggregation. We inserted Foley urinary catheters attached with elastic-wave-generating actuators into the urinary tracts of male rabbits. The treatment with the elastic acoustic waves maintained urine sterility for up to 9 days compared to 2 days in control catheterized animals. Scanning electron microscopy and bioburden analyses revealed diminished biofilm development on these catheters. The ability to prevent biofilm formation on indwelling devices and catheters can benefit the implanted medical device industry.     

Effectiveness of web-based education on Kenyan and Brazilian adolescents' knowledge about HIV/AIDS, abortion law, and emergency contraception: findings from TeenWeb

Little evidence is available about the utility of web-based health education for students in low resource settings. This paper reports results from an evaluation of the TeenWeb project, a multi-year, web-based health education intervention implemented in two urban settings: Nairobi, Kenya (N=1178 school students) and Rio de Janeiro, Brazil (N=714 school students). A quasi-experimental, school-based pre-test/post-test design was implemented at each study site to determine if easy access to web-based reproductive health information, combined with intellectual "priming" about reproductive health topics, would result in improved knowledge and attitudes about topics such as condom use, access to HIV testing, emergency contraception and abortion laws. Students in web-access schools completed one web-based module approximately every 6-8 weeks, and in return, had access to the Internet for at least 30 min after completing each module. Although students were encouraged to access project-supplied web-based health information, freedom of web navigation was an incentive, so they could choose to access other Internet content instead. Most measures showed statistically significant differences between students in "web" and "comparison" conditions at post-test, but only about half of the differences were in the hypothesized direction. Results of an embedded experiment employing more directed feedback tripled the likelihood of correctly reporting the duration of emergency contraception effectiveness. Review of URL logs suggests that the modest results were due to inadequate exposure to educational materials. Future intervention should focus on teen's purposeful searching for health information when they are in personal circumstances of unmet health needs.     

Age‐old care and support practices in Southern Africa functioning robustly as sophisticated social technology interventions

High‐need contexts, such as those in postcolonial Southern Africa, require interventions that provide psychosocial and socioeconomic care and support. This comparative case study uses the lens of indigenous knowledge systems (IKS) to supplement predominantly Western knowledge of care and support interventions. Participatory reflection and action (PRA) were used in 7 conveniently selected Southern African regions reflective of bounded systems with high adversity and likely to portray indigenous belief systems on a regional basis (n = 430; elders = 240; youth = 190; men = 150 and women = 280). Interactive PRA sessions, focusing on generating narratives about traditional care and support strategies, were recorded and analyzed. It emerged that the IKS care and support interventions still being practised are fundamentally relational and pragmatic pathways of resource management, and include reciprocal donations, shared savings in societies, and partnerships and borrowing/lending. Rather than being outdated vestiges of previous times, these age‐old structures continue to function as robust and sophisticated social technologies of care and support.     

Socio-Demographic Variability in Adolescent Substance Use: Mediation by Parents and Peers

The current study examined socio-demographic variability in adolescent substance use and the mediating roles of maternal knowledge, paternal knowledge and peer substance use. The data were obtained from the United States records (N = 8,795) of the Health Behavior in School-Aged Children 2005/2006 Survey, in grades 6 through 10. The analyses employed multiple indicator multiple cause and structural equation models. Adolescent substance use was measured by frequencies of alcohol use, being drunk, and cigarette and marijuana use in the past month. Peer influence had a direct influence on adolescent substance use. Maternal knowledge had both direct and indirect influences on adolescent substance use through its negative association with substance-using peers, whereas paternal knowledge only had an indirect influence. Parental knowledge and peer substance use totally mediated differences in adolescent substance use by grade; differences between Caucasian and African-American or Hispanic adolescents; and differences between adolescents from two-parent families and those from single-mother, single-father or mother-stepfather families. Parental knowledge and peer substance were important mediators which largely accounted for variability in the prevalence of adolescent substance use by grade, race/ethnicity, and family structure.