Structure of a human monoclonal antibody in complex with Outer surface protein C (OspC) of the Lyme disease spirochete, Borreliella burgdorferi.

Lyme disease is a tick-borne, multisystem infection caused by the spirochete, Borreliella burgdorferi . Although antibodies have been implicated in the resolution of Lyme disease, the specific B cell epitopes targeted during human infections remain largely unknown. In this study, we characterized and defined the structural epitope of a patient-derived bactericidal monoclonal IgG ("B11") against Outer surface protein C (OspC), a homodimeric lipoprotein necessary for B. burgdorferi tick-mediated transmission and early-stage colonization of vertebrate hosts. High-resolution epitope mapping was accomplished through hydrogen deuterium exchange-mass spectrometry (HDX-MS) and X-ray crystallography. Structural analysis of B11 Fab-OspC A complexes revealed the B11 Fabs associated in a 1:1 stoichiometry with the lateral faces of OspC A homodimers such that the antibodies are essentially positioned perpendicular to the spirochete's outer surface. B11's primary contacts reside within the membrane proximal regions of α-helices 1 and 6 and adjacent loops 5 and 6 in one OspC A monomer. In addition, B11 spans the OspC A dimer interface, engaging opposing α-helix 1', α-helix 2', and loop 2-3' in the second OspC A monomer. The B11-OspC A structure is reminiscent of the recently solved mouse transmission blocking monoclonal IgG B5 in complex with OspC A , indicating a mode of engagement with OspC that is conserved across species. In conclusion, we provide the first detailed insight into the interaction between a functional human antibody and an immunodominant Lyme disease antigen long considered an important vaccine target.

Diesel Engine Exhaust Exposure in Relation to Lung Cancer in Long-Haul Truck Drivers: An Eight-Step Concept Analysis.

BACKGROUND: Long-haul truck drivers (LHTDs) face a number of occupational hazards. One such hazard is exposure to diesel engine exhaust (DEE). However, this concept has yet to be analyzed. To address this gap, a concept analysis was conducted to explore the effects of DEE in relation to lung cancer. METHODS: Walker and Avant's eight-step concept analysis method was utilized: concept selection, analysis purpose, concept uses, defining attributes, model case, borderline case, antecedents and consequences, and empirical referents. PubMed, Scopus, and CINAHL databases were searched for relevant literature. FINDINGS: Diesel engine exhaust was identified as a mixture of gases and particulates that are considered carcinogenic. Defining attributes of DEE for truckers include respiratory effects such as decreased peak flow and increased airway resistance leading to symptoms such as a phlegm-producing cough, eye and throat irritation, exacerbation of asthma symptoms, and allergic responses. The identified level of DEE exposure associated with these attributes is 75 µg EC/m3 for 1 to 2 hours daily or a long-term exposure of 10 µg EC/m3. The conceptual definition of DEE in truckers was illustrated by the attributes, antecedents, consequences, model case, and empirical referents. CONCLUSION: Lung cancer was identified as a significant consequence of occupational DEE exposure for LHTDs. This analysis highlights the need for future research to develop interventions that will safeguard truckers from the adverse health effects of DEE exposure.

Project EPIC (Empowering People to Independence in COPD): Study protocol for a hybrid effectiveness-implementation pilot randomized controlled trial of telephonic, geriatrics-palliative care nurse-coaching in older adults with COPD and their family caregivers.

BACKGROUND: EPIC (Empowering People to Independence in COPD) is a geriatric-palliative care telephonic, nurse coach intervention informed by Baltes' Theory of Successful Aging and adapted from the ENABLE (Educate, Nurture, Advise, Before Life Ends) intervention. EPIC, focused on improving independence, mobility, well-being, and COPD symptoms, has undergone formative and summative evaluation for adults with COPD. METHODS: The primary study aim is to assess the refined EPIC intervention's feasibility and acceptability via a pilot hybrid effectiveness-implementation randomized control trial in community-dwelling older adults with moderate to severe COPD and their family caregivers. The secondary aim is to explore the impact of EPIC on patient and caregiver outcomes. Older adults with COPD and their family caregivers (target N = 60 dyads) will be randomized to EPIC (intervention) or usual COPD care (control). EPIC includes six patient and four family caregiver weekly, telephone-based nurse coach sessions using a manualized curriculum (Charting Your Course), plus three monthly follow-up calls. Feasibility will be measured as completion of EPIC intervention and trial components (e.g., recruitment, retention, data collection). Acceptability will be evaluated using satisfaction surveys and post-study feedback interviews. A blinded data collector will assess exploratory outcomes (e.g., Life-Space mobility, quality of life, caregiver burden, emotional symptoms, loneliness, cognitive impairment, functional status, healthcare utilization) at baseline, 12, and 24 weeks. DISCUSSION: This intervention fills a gap in addressing the geriatrics and palliative care needs and equity for adults with COPD and their family caregivers. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05040386.

Single-domain antibodies reveal unique borrelicidal epitopes on the Lyme disease vaccine antigen, outer surface protein A (OspA).

Camelid-derived, single-domain antibodies (VHHs) have proven to be extremely powerful tools in defining the antigenic landscape of immunologically heterogeneous surface proteins. In this report, we generated a phage-displayed VHH library directed against the candidate Lyme disease vaccine antigen, outer surface protein A (OspA). Two alpacas were immunized with recombinant OspA serotype 1 from Borrelia burgdorferi sensu stricto strain B31, in combination with the canine vaccine RECOMBITEK Lyme containing lipidated OspA. The phage library was subjected to two rounds of affinity enrichment ("panning") against recombinant OspA, yielding 21 unique VHHs within two epitope bins, as determined through competition enzyme linked immunosorbent assays (ELISAs) with a panel of OspA-specific human monoclonal antibodies. Epitope refinement was conducted by hydrogen exchange-mass spectrometry. Six of the monovalent VHHs were expressed as human IgG1-Fc fusion proteins and shown to have functional properties associated with protective human monoclonal antibodies, including B. burgdorferi agglutination, outer membrane damage, and complement-dependent borreliacidal activity. The VHHs displayed unique reactivity profiles with the seven OspA serotypes associated with B. burgdorferi genospecies in the United States and Europe consistent with there being unique epitopes across OspA serotypes that should be considered when designing and evaluating multivalent Lyme disease vaccines.

Symptomatology and Quality of Life of Older People With HIV and Comorbid Chronic Obstructive Pulmonary Diseases From an HIV Clinic in Birmingham, Alabama.

ABSTRACT: Psychological symptomatology and quality of life (QoL) have been studied in older people with HIV (PWH) and those with chronic obstructive pulmonary disease (COPD), respectively, but there is a dearth of studies in older PWH with COPD. Our study compared depressive symptoms, anxiety, and QoL between older PWH with and without COPD using data from an HIV clinic in Birmingham, Alabama, from January 2018 to February 2020. Data on depressive symptoms (Patient Health Questionnaire-9), anxiety (Patient Health Questionnaire-5 Anxiety), and QoL (EuroQoL-5 Dimension) were analyzed. Among 690 PWH aged 50 years or older, 102 individuals (14.8%) had COPD. Significant differences were found between the two groups in depressive symptoms and components of QoL (e.g., mobility, self-care, usual activities, and pain/discomfort), but not in anxiety and general health. Experiencing COPD may worsen depressive symptomatology and QoL in older PWH, highlighting the need for tailored health care and research for this population.

"As I Grew Older, My Life Got Better": Conceptions of Successful Aging among Older Women Living with or at Risk of HIV.

Successful aging (SA) is an important target for HIV care. However, we have insufficient understanding of how older women living with HIV (OWLH) in the US define SA. We explored conceptions of SA by OWLH and older women at risk of HIV and examined whether SA conceptions differed by (1) HIV serostatus, and (2) participation in the Women's Interagency HIV Study (WIHS). These analyses were part of a larger mixed-methods study with a sequential design. Participants were recruited at two clinical WIHS sites. We enrolled both WIHS participants and non-WIHS clinic patients. Our sample was 84% Black and included 29 OWLH and 15 older women at risk of HIV. We conducted 21 semi-structured interviews and four focus groups. The dataset was analyzed using descriptive, comparative, and relational analysis. We found four interlinked themes: life course perspective, accepting and celebrating aging, taking care of yourself, and looking good. The life course perspective was a core theme: participants assessed their aging in comparison to their earlier life hardships. These themes were similarly present among OWLH and older women at risk of HIV, although OWLH emphasized taking care of HIV. SA conceptualizations by OWLH did not differ whether or not they participated in the WIHS. Women living with or at risk of HIV may experience severe hardships throughout their lives. Overcoming these hardships may be linked to SA. Assessing the needs and connecting women to resources and programs are critical for SA promotion.

Does Olfactory Training Improve Brain Function and Cognition? A Systematic Review.

Olfactory training (OT), or smell training,consists of repeated exposure to odorants over time with the intended neuroplastic effect of improving or remediating olfactory functioning. Declines in olfaction parallel declines in cognition in various pathological conditions and aging. Research suggests a dynamic neural connection exists between olfaction and cognition. Thus, if OT can improve olfaction, could OT also improve cognition and support brain function? To answer this question, we conducted a systematic review of the literature to determine whether there is evidence that OT translates to improved cognition or altered brain morphology and connectivity that supports cognition. Across three databases (MEDLINE, Scopus, & Embase), 18 articles were identified in this systematic review. Overall, the reviewed studies provided emerging evidence that OT is associated with improved global cognition, and in particular, verbal fluency and verbal learning/memory. OT is also associated with increases in the volume/size of olfactory-related brain regions, including the olfactory bulb and hippocampus, and altered functional connectivity. Interestingly, these positive effects were not limited to patients with smell loss (i.e., hyposmia & anosmia) but normosmic (i.e., normal ability to smell) participants benefitted as well. Implications for practice and research are provided.

A 2-year longitudinal randomized controlled trial examining the transfer of speed of processing training to secondary cognitive domains in middle-aged and older adults with HIV-associated neurocognitive disorder: Results of the think fast study.

OBJECTIVE: As people with HIV (PWH) age, they are at-risk of developing cognitive impairments compared to their seronegative counterparts. Although speed of processing (SOP) training may help improve this cognitive ability, less work has examined transfer to other cognitive domains. This study examined the effect of SOP training has on secondary cognitive domains in PWH aged 40+ years. METHOD: In this 3-group 2-year longitudinal study, 216 PWH with HIV-associated neurocognitive disorder (HAND) or borderline HAND were randomized to either: (1) 10 h of SOP training (n = 70); (2) 20 h of SOP training (n = 73); or (3) 10 h of an active control training (n = 73). Participants completed a comprehensive cognitive battery at baseline, immediately after training, and at 1 and 2 years. This battery yielded global and domain specific T-scores as well as a cognitive impairment variable. Generalized linear mixed-effect models were fitted to estimate between-group mean differences at the follow-up time-points adjusted for baseline. RESULTS: No clinically or statistically significant improvements in any of the cognitive outcomes were observed. A sensitivity analysis was conducted; conclusions replicated those of the main analysis, with two exceptions: Global Function T and Psychomotor Speed T showed relevant training improvements among the intervention groups over the control group at the immediate post time point. CONCLUSIONS: Although SOP training has been shown to improve cognitive abilities that correspond to driving and mobility, such training has limited therapeutic utility in improving cognition in other domains in PWH with HAND.

Cognitive prescriptions for reducing dementia risk factors among Black/African Americans: feasibility, acceptability, and preliminary efficacy.

OBJECTIVES: Black/African Americans (B/AAs) have double the risk of Alzheimer's disease and related dementia than Whites, which is largely driven by health behaviors. This study examined the feasibility, acceptability, and preliminary efficacy of a pilot randomized clinical trial of an individualized multidomain health behavior intervention among middle-aged and older B/AAs (dubbed Cognitive Prescriptions [CogRx]). DESIGN: Thirty-nine community-dwelling B/AA participants aged 45-65 without significant cognitive impairment were randomized to one of three groups: CogRx, Psychoeducation, or no-contact control. The Psychoeducation and CogRx groups received material on dementia prevalence, prognosis, and risk factors, while the CogRx group additionally received information on their risk factor profile across the five CogRx domains (physical, cognitive, and social activity, diet, sleep). This information was used for developing tailored 3-month goals in their suboptimal areas. RESULTS: The CogRx program had high retention (all 13 CogRx participants completed the 3-month program and 97% of the full sample completed at least 1 follow-up) and was well-received as exhibited by qualitative and quantitative feedback. Themes identified in the positive feedback provided by participants on the program included: increased knowledge, goal-setting, personalization, and motivation. The COVID-19 pandemic was a consistent theme that emerged regarding barriers of adherence to the program. All three groups improved on dementia knowledge, with the largest effects observed in CogRx and Psychoeducation groups. Increases in cognitive, physical, and overall leisure activities favored the CogRx group, whereas improvements in sleep outcomes favored Psychoeducation and CogRx groups as compared to the control group. CONCLUSION: The CogRx program demonstrated feasibility, acceptability, and preliminary efficacy in increasing dementia knowledge and targeted health behaviors. Further refinement and testing of the implementation and effectiveness of similar person-centered dementia prevention approaches are needed on a larger scale in diverse populations. Such findings may have implications for clinical and public health recommendations. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03864536.

Associations Between Estimates of Arterial Stiffness and Cognitive Functioning in Adults With HIV.

BACKGROUND: Vascular aging, a precursor of arterial stiffness, is associated with neurocognitive impairment (NCI) and cardiovascular disease. Although HIV is associated with rapid vascular aging, it is unknown whether arterial stiffness mediates changes in cognitive function. We explored whether estimated markers of vascular aging were associated with NCI indices in HIV-positive individuals. METHODS: This study was a secondary analysis of an observational study. Neurocognitive functioning was assessed using a battery of 7 domains (verbal fluency, executive functioning, speed of information processing, attention/working memory, memory [learning and delayed recall], and motor skills). Vascular aging was assessed using estimated markers of arterial stiffness (ie, estimated pulse wave velocity, pulse pressure, and vascular overload index). A multivariable regression adjusted for demographics, cardiovascular disease risk factors, and HIV clinical variables was used to examine the association between vascular aging and NCI outcomes. RESULTS: Among 165 people with HIV, the mean age was 51.5 ± 6.9 years (62% men and 83% African American/Black or Other). In fully adjusted models, an increase in estimated pulse wave velocity and pulse pressure was associated with lower T scores in learning (-2.95 [-5.13, -0.77]) and working memory (-2.37 [-4.36, -0.37]), respectively. An increase in vascular overload index was associated with lower T scores in working memory (-2.33 [-4.37, -0.29]) and learning (-1.85 [-3.49, -0.21]). CONCLUSIONS: Estimated markers of arterial stiffness were weakly associated with neurocognitive functioning, suggesting that vascular aging may have a role in cognitive decline among people with HIV.

Advances in NIR-Responsive Natural Macromolecular Hydrogel Assembly Drugs for Cancer Treatment.

Cancer is a serious disease with an abnormal proliferation of organ tissues; it is characterized by malignant infiltration and growth that affects human life. Traditional cancer therapies such as resection, radiotherapy and chemotherapy have a low cure rate and often cause irreversible damage to the body. In recent years, since the traditional treatment of cancer is still very far from perfect, researchers have begun to focus on non-invasive near-infrared (NIR)-responsive natural macromolecular hydrogel assembly drugs (NIR-NMHADs). Due to their unique biocompatibility and extremely high drug encapsulation, coupling with the spatiotemporal controllability of NIR, synergistic photothermal therapy (PTT), photothermal therapy (PDT), chemotherapy (CT) and immunotherapy (IT) has created excellent effects and good prospects for cancer treatment. In addition, some emerging bioengineering technologies can also improve the effectiveness of drug delivery systems. This review will discuss the properties of NIR light, the NIR-functional hydrogels commonly used in current research, the cancer therapy corresponding to the materials encapsulated in them and the bioengineering technology that can assist drug delivery systems. The review provides a constructive reference for the optimization of NIR-NMHAD experimental ideas and its application to human body.

Plasma Biomarkers of Alzheimer Disease in Women With and Without HIV.

Importance: Blood-based biomarkers associated with increased risk of Alzheimer disease (AD) are understudied in people living with and without HIV, particularly women. Objective: To determine whether baseline or 1-year changes in plasma amyloid-ß40 (Aß40), Aß42, ratio of Aß42 to Aß40, total tau (t-tau), phosphorylated tau 231 (p-tau231), glial fibrillary acidic protein (GFAP), and/or neurofilament light chain (NFL) are associated with neuropsychological performance (NP) among women living with HIV (WLWH) and women living without HIV (WLWOH). Design, Setting, and Participants: This longitudinal, prospective, cohort study with 1-year repeated clinical measures (NP only measured once) and biospecimen collection occurred between 2017 and 2019. Participants were women aged 40 years or older from 10 clinical research sites in cities across the US that were part of the Women's Interagency HIV Study. Data analysis was conducted from April to December 2022. Exposure: Laboratory-confirmed HIV status and AD biomarkers. Main Outcomes and Measures: Sociodemographically adjusted NP T-scores (attention and working memory, executive function, processing speed, memory, learning, verbal fluency, motor function, and global performance) were the primary outcomes. Baseline and 1-year fasting plasma Aß40, Aß42, t-tau, p-tau231, GFAP, and NFL levels were measured and analyzed using multivariable linear regression. Results: The study consisted of 307 participants (294 aged ≥50 years [96%]; 164 African American or Black women [53%]; 214 women with a high school education or higher [70%]; 238 women who were current or former smokers [78%]; and 236 women [77%] who were overweight or obese [body mass index >25]) including 209 WLWH and 98 WLWOH. Compared with WLWOH at baseline, WLWH performed worse on learning (mean [SD] T-score 47.8 [11.3] vs 51.4 [10.5]), memory (mean [SD] T-score 48.3 [11.6] vs 52.4 [10.2]), verbal fluency (mean [SD] T-score 48.3 [9.8] vs 50.7 [8.5]), and global (mean [SD] T-score 49.2 [6.8] vs 51.1 [5.9]) NP assessments. Baseline median Aß40, GFAP, and NFL levels were higher among WLWH vs WLWOH. There were no differences in 1-year biomarker change by HIV serostatus. Lower learning, memory, and motor NP were associated with 1-year Aß40 increase; lower learning and motor with Aß42 increase; lower motor with p-tau231 increase; and lower processing speed, verbal fluency and motor with NFL increase in the entire sample. Among WLWH, a 1-year increase in Aß40 from baseline to follow-up was associated with worse learning, memory, and global NP; a 1-year increase in t-tau with worse executive function; and a 1-year increase in NFL with worse processing speed. Among WLWOH, a 1-year increase in Aß40 and Aß42 were associated with poorer memory performance and NFL was associated with poorer motor performance. Conclusions and Relevance: These findings suggest that increases in certain plasma AD biomarkers are associated with NP in WLWH and WLWOH and may be associated with later onset of AD, and measuring these biomarkers could be a pivotal advancement in monitoring aging brain health and development of AD among women with and without HIV.

The Association Between Intrapersonal Resilience Resources and Quality of Life Among Older Persons Living With HIV: A Systematic Review.

ABSTRACT: Despite positive improvements in health care, older persons living with HIV (PWH) still face psychosocial challenges and medical issues that affect their overall quality of life (QoL). Intrapersonal resilience resources may serve as a protective factor allowing PWH to better cope with adversity, thereby improving their well-being. In our systematic review, we examined intrapersonal resilience resources and their association with QoL outcomes among middle-aged and older PWH (≥40 years). Four databases (CINAHL, PubMed, PsycINFO, and Embase) were searched, and 1,400 articles were yielded. Following screening and full-text review, 19 studies met full criteria and were included. Based on our findings from these studies, trait resilience, spirituality, and self-efficacy were the most common resilience resources investigated. Resilience resources were positively associated with QoL outcomes and mediated the association between various psychosocial factors (e.g., stigma) and QoL. Future studies should explore resilience resources and QoL over time among diverse populations of PWH.

Structural Basis of Antibody-Mediated Inhibition of Ricin Toxin Attachment to Host Cells.

Monoclonal antibodies, JB4 and SylH3, neutralize ricin toxin (RT) by inhibiting the galactose-specific lectin activity of the B subunit of the toxin (RTB), which is required for cell attachment and entry. It is not immediately apparent how the antibodies accomplish this feat, considering that RTB consists of two globular domains (D1, D2) each divided into three homologous subdomains (α, ß, γ) with the two functional galactosyl-specific carbohydrate recognition domains (CRDs) situated on opposite poles (subdomains 1α and 2γ). Here, we report the X-ray crystal structures of JB4 and SylH3 Fab fragments bound to RTB in the context of RT. The structures revealed that neither Fab obstructed nor induced detectable conformational alterations in subdomains 1α or 2γ. Rather, JB4 and SylH3 Fabs recognize nearly identical epitopes within an ancillary carbohydrate recognition pocket located in subdomain 1ß. Despite limited amino acid sequence similarity between SylH3 and JB4 Fabs, each paratope inserts a Phe side chain from the heavy (H) chain complementarity determining region (CDR3) into the 1ß CRD pocket, resulting in local aromatic stacking interactions that potentially mimic a ligand interaction. Reconciling the fact that stoichiometric amounts of SylH3 and JB4 are sufficient to disarm RTB's lectin activity without evidence of allostery, we propose that subdomain 1ß functions as a "coreceptor" required to stabilize glycan interactions principally mediated by subdomains 1α and 2γ. Further investigation into subdomain 1ß will yield fundamental insights into the large family of R-type lectins and open novel avenues for countermeasures aimed at preventing toxin uptake into vulnerable tissues and cells.

Cognitive intra-individual variability in breast cancer survivors: A systematic review.

Subjective and objective cognitive impairments in Breast Cancer Survivors (BCS) often do not correlate. One important contribution to the reported disparities may be the reliance on mean-based cognitive performance. Cognitive intra-individual variability (IIV) may provide important insights into these reported disparities. Cognitive IIV refers to the fluctuation in performance for an individual on either one cognitive task across a trial or dispersed across tasks within a neuropsychological test battery. The purpose of this systematic review was to search for and examine the literature on cognitive IIV in BCS. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach was used to search for all articles related to cognitive IIV in BCS. MEDLINE (via PubMed), Embase, and Scopus databases were searched using detailed search terms and strategies. Initially, 164 articles were retrieved but only 4 articles met the criteria for this systematic review. BCS differed from healthy controls in similar ways across the four studies, generally demonstrating similar performance but showing increased cognitive IIV for the more difficult tasks. Differences were enhanced later during chemotherapy. The four studies provide support for cognitive IIV as a useful measure to detect the subtle objective cognitive change often reported by BCS but frequently not detected by standard normed-based cognitive testing. Unexpectedly, measures of cognitive IIV were not consistently associated with self-reported measures of cognition.

Preventing Neurocognitive Decline in Adults Aging with HIV: Implications for Practice and Research.

Mild to moderate forms of neurocognitive impairment persist among people living with HIV (PLWH), despite being virally suppressed on antiretroviral therapy. PLWH are disproportionally impacted by physiological and psychosocial comorbidities compared to those without HIV. As adults live longer with HIV, the neurocognitive burden of physiological and psychosocial stressors can impair everyday functioning and may contribute to the development of neurodegenerative diseases such as Alzheimer's disease. This article outlines neurocognitive consequences of everyday stressors in PLWH. While some lifestyle factors can exacerbate inflammatory processes and promote negative neurocognitive health, novel interventions including the use of cannabinoids may be neuroprotective for aging PLWH who are at risk for elevated levels of inflammation from comorbidities. Studies of integrated neurocognitive rehabilitation strategies targeting lifestyle factors are promising for improving neurocognitive health, and may over time, reduce the risk of Alzheimer's disease in PLWH.