Structural and Mechanistic Bases of Viral Resistance to HIV-1 Capsid Inhibitor Lenacapavir.

Lenacapavir (LEN) is a long-acting, highly potent HIV-1 capsid (CA) inhibitor. The evolution of viral variants under the genetic pressure of LEN identified Q67H, N74D, and Q67H/N74D CA substitutions as the main resistance associated mutations (RAMs). Here, we determined high-resolution structures of CA hexamers containing these RAMs in the absence and presence of LEN. Our findings reveal that the Q67H change induces a conformational switch, which adversely affects the inhibitor binding. In the unliganded protein, the His67 side chain adopts the closed conformation by projecting into the inhibitor binding pocket and thereby creating steric hindrance with respect to LEN. Upon the inhibitor binding, the His67 side chain repositions to the open conformation that closely resembles the Gln67 side chain in the WT protein. We propose that the switch from the closed conformation to the open conformation, which is needed to accommodate LEN, accounts for the reduced inhibitor potency with respect to the Q67H CA variant. The N74D CA change results in the loss of a direct hydrogen bond and in induced electrostatic repulsions between CA and LEN. The double Q67H/N74D substitutions exhibited cumulative effects of respective single amino acid changes. An examination of LEN binding kinetics to CA hexamers revealed that Q67H and N74D CA changes adversely influenced the inhibitor binding affinity (KD) by primarily affecting the dissociation rate constant (koff). We used these structural and mechanistic findings to rationally modify LEN. The resulting analog exhibited increased potency against the Q67H/N74D viral variant. Thus, our studies provide a means for the development of second-generation inhibitors with enhanced barriers to resistance. IMPORTANCE LEN is an investigational long-acting agent for future HIV-1 treatment regimens. While ongoing clinical trials have highlighted a largely beneficial profile of LEN for the treatment of HIV-1 infected people with limited therapy options, one notable shortcoming is a relatively low barrier of viral resistance to the inhibitor. Cell culture-based viral breakthrough assays identified N74D, Q67H, and N74D/Q67H capsid changes as the main resistance associated mutations (RAMs). N74D and Q67H capsid substitutions have also emerged in clinical trials in some patients who received subcutaneous LEN. Understanding the structural basis behind viral resistance to LEN is expected to aid in the rational development of improved inhibitors with enhanced barriers to resistance. Here, we report high resolution structures of the main drug resistant capsid variants, which provide mechanistic insight into the viral resistance to LEN. We used these findings to develop an improved inhibitor, which exhibited enhanced activity against the viral Q67H/N74D capsid phenotype compared with that of parental LEN.

Cross-cultural comparison of long-term care in the United States and Finland: Research done through a short-term study-abroad experience.

In May 2014, a short-term study-abroad experience was conducted in Finland through a course offered at Indiana State University (ISU). Students and faculty from ISU and Eastern Illinois University participated in the experience, which was created to facilitate a cross-cultural comparison of long-term-care settings in the United States and Finland. With its outstanding system of caring for the health and social needs of its aging populace, Finland is a logical model to examine when considering ways to improve the quality of life for older adults who require care in the United States . Those participating in the course visited a series of long-term-care facilities in the region surrounding Terre Haute, Indiana, then travelled to Lappeenranta, Finland to visit parallel sites. Through limited-participation observation and semistructured interviews, similarities and differences in experiences, educations, and policies affecting long-term care workers in the United States and Finland were identified and are described here.

Age Changes in Prosocial Responding and Moral Reasoning in Adolescence and Early Adulthood.

Age changes' measures of prosocial responding and reasoning were examined. Participants' reports of helping, empathy-related responding, and prosocial moral reasoning were obtained in adolescence (from age 15-16 years) and into adulthood (to age 25-26 years). Perspective taking and approval/interpersonal oriented/stereotypic prosocial moral reasoning increased from adolescence into adulthood, whereas personal distress declined. Helping declined and then increased (a cubic trend). Prosocial moral judgment composite scores (and self-reflective empathic reasoning) generally increased from late adolescence into the early 20s (age 17-18 to 21-22) but either leveled off or declined slightly thereafter (i.e., showed linear and cubic trends); rudimentary needs-oriented reasoning showed the reverse pattern of change. The increase in self-reflective empathic moral reasoning was for females only. Thus, perspective taking and some aspects of prosocial moral reasoning-capacities with a strong sociocognitive basis-showed the clearest increases with age, whereas simple prosocial proclivities (i.e., helping, sympathy) did not increase with age.

Children's physiological indices of empathy and their socioemotional adjustment: does caregivers' expressivity matter?

Relations of heart rate and skin conductance reactions to mildly evocative empathy-inducing slides with socioemotional functioning were examined for 154 children (mean age = 9 years, 5 months). In addition, maternal expressivity was tested as a moderator of these relations. Parents and teachers rated children's socioemotional functioning, and a behavioral measure of children's regulation was obtained. Boys who exhibited higher skin conductance and higher heart rate to slides depicting negative emotions were better regulated, less emotionally intense, and better adjusted than their peers. Furthermore, boys' regulation and adjustment were positively related to such physiological responding to negative slides if maternal negative expressivity was relatively low or moderate, but not high. Fewer findings were obtained for girls or for positive slides.

The relations of effortful control and reactive control to children's externalizing problems: a longitudinal assessment.

In this study, we examined the role of negative emotionality as a moderator of the relations of effortful control and overcontrol (versus undercontrol) with children's externalizing problem behaviors; we also examined the longitudinal relations among these variables. Teachers' and parents' reports of children's negative emotionality, effortful control, overcontrol and externalizing problem behaviors were obtained at T1 (N=199; M age=89.51 months) and again 2 (T2) and 4 years (T3) later. In addition, children's effortful control was assessed with an observed measure of persistence. In a T3 concurrent structural equation model, effortful control, but not overcontrol, was negatively related to children's T3 externalizing problem behaviors. In regression analyses, the negative relation between T3 effortful control and externalizing problem behaviors was strongest at high levels of T3 negative emotionality. In the best-fitting longitudinal structural equation model, both T1 effortful control and T1 overcontrol negatively predicted externalizing problems at T1, whereas T3 effortful control (but not T3 overcontrol) was significantly negatively related to T3 externalizing problem behaviors when controlling for T1 externalizing problem behaviors.

The relations of effortful control and ego control to children's resiliency and social functioning.

The relations of effortful control and ego control to children's (mean age = 137 months) resiliency, social status, and social competence were examined concurrently (Time 3) and over time. Adults reported on the constructs, and a behavioral measure of persistence was obtained. At Time 3, resiliency mediated the unique relations of both effortful and reactive control to social status, and effortful control directly predicted socially appropriate behavior. Negative emotionality moderated the relations of ego and effortful control to socially appropriate behavior. When levels of the variables 2 years prior were accounted for, all relations held at Time 3 except that effortful control did not predict resiliency (even though it was the stronger predictor at Time 3) and ego control directly predicted socially appropriate behavior.

The relations of parenting, effortful control, and ego control to children's emotional expressivity.

The relations of observed parental warmth and positive expressivity and children's effortful control and ego control with children's high versus low emotional expressivity were examined in a 2-wave study of 180 children (M age = 112.8 months). There were quadratic relations between adults' reports of children's emotional expressivity and effortful control; moderate expressivity was associated with high effortful control. Structural equation models supported the hypothesis that children's ego overcontrol (versus undercontrol) mediated the relation between parental warmth or positive expressivity and children's emotional expressivity, although parenting at the follow-up did not uniquely predict in children's expressivity after controlling for the relations in these constructs over time. The alternative hypothesis that children's ego overcontrol elicited positive parenting and expressivity also was supported.

The relations of parental warmth and positive expressiveness to children's empathy-related responding and social functioning: a longitudinal study.

This study examined the concurrent and cross-time relations of parental observed warmth and positive expressivity to children's situational facial and self-reported empathic responding, social competence, and externalizing problems in a sample of 180 elementary school children. Data was collected when the children were in second to fifth grades (age: M = 112.8 months), and again 2 years later. Cross-sectional and longitudinal structural equation models supported the hypothesis that parents' (mostly mothers') positive expressivity mediated the relation between parental warmth and children's empathy, and children's empathy mediated the relation between parental positive expressivity and children's social functioning. These relations persisted after controlling for prior levels of parenting and child characteristics. Moreover, concurrent and cross-time consistencies were found on measures of parenting, children's situational empathic responding, and social functioning.

Prosocial development in early adulthood: a longitudinal study.

Consistency of measures of a prosocial personality and prosocial moral judgment over time, and the interrelations among them, were examined. Participants and friends' reports of prosocial characteristics were obtained at ages 21-22, 23-24, and 25-26 years. In addition, participants' prosocial judgment was assessed with interviews and with an objective measure of prosocial moral reasoning at several ages. Reports of prosocial behavior and empathy-related responding in childhood and observations of prosocial behavior in preschool also were obtained. There was interindividual consistency in prosocial dispositions, and prosocial dispositions in adulthood related to empathy/sympathy and prosocial behavior at much younger ages. Interview and objective measures of moral reasoning were substantially interrelated in late adolescence/early adulthood and correlated with participants' and friends' reports of a prosocial disposition.