Binding of Clinical Inhibitors to a Model Precursor of a Rationally Selected Multidrug Resistant HIV-1 Protease Is Significantly Weaker Than That to the Released Mature Enzyme.

We have systematically validated the activity and inhibition of a HIV-1 protease (PR) variant bearing 17 mutations (PR(S17)), selected to represent high resistance by machine learning on genotype-phenotype data. Three of five mutations in PR(S17) correlating with major drug resistance, M46L, G48V, and V82S, and five of 11 natural variations differ from the mutations in two clinically derived extreme mutants, PR20 and PR22 bearing 19 and 22 mutations, respectively. PR(S17), which forms a stable dimer (<10 nM), is ∼10- and 2-fold less efficient in processing the Gag polyprotein than the wild type and PR20, respectively, but maintains the same cleavage order. Isolation of a model precursor of PR(S17) flanked by the 56-amino acid transframe region (TFP-p6pol) at its N-terminus, which is impossible upon expression of an analogous PR20 precursor, allowed systematic comparison of inhibition of TFP-p6pol-PR(S17) and mature PR(S17). Resistance of PR(S17) to eight protease inhibitors (PIs) relative to PR (Ki) increases by 1.5-5 orders of magnitude from 0.01 to 8.4 µM. Amprenavir, darunavir, atazanavir, and lopinavir, the most effective of the eight PIs, inhibit precursor autoprocessing at the p6pol/PR site with IC50 values ranging from ∼7.5 to 60 µM. Thus, this process, crucial for stable dimer formation, shows inhibition ∼200-800-fold weaker than that of the mature PR(S17). TFP/p6pol cleavage, which occurs faster, is inhibited even more weakly by all PIs except darunavir (IC50 = 15 µM); amprenavir shows a 2-fold increase in IC50 (∼15 µM), and atazanavir and lopinavir show increased IC50 values of >42 and >70 µM, respectively.

Granulomatous-lymphocytic interstitial lung disease (GLILD) in common variable immunodeficiency (CVID).

Infectious complications of the lung occur quite frequently in patients with common variable immunodeficiency (CVID), a clinical syndrome that represents a primary immunodeficiency. However, there appears to be noninfectious pulmonary complications in association with CVID as well, and recently the term granulomatous-lymphocytic interstitial lung disease (GLILD) has been created to describe these noninfectious, diffuse lung disease complications that develop in CVID patients. They exhibit both granulomatous and lymphoproliferative histologic patterns, consisting of lymphocytic interstitial pneumonia (LIP), follicular bronchiolitis, and lymphoid hyperplasia. There are many unanswered questions surrounding this relatively unstudied entity. In an attempt to answer some of these questions, this review discusses in detail pathologic and clinical features of GLILD and its proposed pathogenesis with a particular attention to potential role of human herpesvirus 8 (HHV-8). Lastly, therapeutic approach is discussed to generate novel treatment strategy to better care for a subgroup of CVID patients afflicted with this entity.

Altered Brain Connectivity in Early Postmenopausal Women with Subjective Cognitive Impairment.

Cognitive changes after menopause are a common complaint, especially as the loss of estradiol at menopause has been hypothesized to contribute to the higher rates of dementia in women. To explore the neural processes related to subjective cognitive complaints, this study examined resting state functional connectivity in 31 postmenopausal women (aged 50-60) in relationship to cognitive complaints following menopause. A cognitive complaint index was calculated using responses to a 120-item questionnaire. Seed regions were identified for resting state brain networks important for higher-order cognitive processes and for areas that have shown differences in volume and functional activity associated with cognitive complaints in prior studies. Results indicated a positive correlation between the executive control network and cognitive complaint score, weaker negative functional connectivity within the frontal cortex, and stronger positive connectivity within the right middle temporal gyrus in postmenopausal women who report more cognitive complaints. While longitudinal studies are needed to confirm this hypothesis, these data are consistent with previous findings suggesting that high levels of cognitive complaints may reflect changes in brain connectivity and may be a potential marker for the risk of late-life cognitive dysfunction in postmenopausal women with otherwise normal cognitive performance.

IgH sequences in common variable immune deficiency reveal altered B cell development and selection.

Common variable immune deficiency (CVID) is the most common symptomatic primary immune deficiency, affecting ~1 in 25,000 persons. These patients suffer from impaired antibody responses, autoimmunity, and susceptibility to lymphoid cancers. To explore the cellular basis for these clinical phenotypes, we conducted high-throughput DNA sequencing of immunoglobulin heavy chain gene rearrangements from 93 CVID patients and 105 control subjects and sorted naïve and memory B cells from 13 of the CVID patients and 10 of the control subjects. The CVID patients showed abnormal VDJ rearrangement and abnormal formation of complementarity-determining region 3 (CDR3). We observed a decreased selection against antibodies with long CDR3s in memory repertoires and decreased variable gene replacement, offering possible mechanisms for increased patient autoreactivity. Our data indicate that patient immunodeficiency might derive from both decreased diversity of the naïve B cell pool and decreased somatic hypermutation in memory repertoires. The CVID patients also exhibited an abnormal clonal expansion of unmutated B cells relative to the controls. Although impaired B cell germinal center activation is commonly viewed as causative in CVID, these data indicate that CVID B cells diverge from controls as early as the pro-B stage, cell and suggest possible explanations for the increased incidence of autoimmunity, immunodeficiency, and lymphoma CVID patients.

Perspectives on common variable immune deficiency.

Common variable immunodeficiency (CVID) is considered to be a collection of genetic immune defects with complex inheritance patterns. While the main phenotype is loss of B cell function, the majority of the genetic mechanisms leading to CVID remain elusive. In the past two decades there have been increasing efforts to unravel the genetic defects in CVID. Here, we provide an overview of our current understanding of the genetic basis of these defects, as revealed over time by earlier linkage studies in large cohorts, analysis of families with recessive inheritance, targeted gene approaches, and genome-wide association studies using single nucleotide polymorphism arrays and copy number variation, and whole genome studies.

Combined impact of adiponectin and retinol-binding protein 4 on metabolic syndrome in elderly people: the Korean Longitudinal Study on Health and Aging.

The prevalence of metabolic syndrome (MS) increases with progressing and is potentially associated with changes in adipose-derived cytokines, including adiponectin and retinol-binding protein 4 (RBP4). We aimed to determine the prevalence of MS, and the relationships between these factors and MS in elderly people. A population-based cohort study, the Korean Longitudinal Study on Health and Aging (KLoSHA), was performed on subjects aged > or =65 years by random stratified sampling in 2005-2006 (439 men and 561 women). Anthropometrics, biochemical factors including adiponectin and RBP4 levels, body composition, and abdominal fat by computed tomography (CT) were measured. The prevalence of MS was 61.0% in women and 39.9% in men. After adjustment for age, gender, smoking, alcohol, and exercise status and muscle mass, participants with the lowest quartile of adiponectin had a higher risk for having MS than those with the highest quartile (odds ratio (OR) = 4.12, P < 0.01). Similarly, subjects with the highest quartile of RBP4 showed an increased risk for having MS (OR = 1.73, P < 0.01). When both the lowest adiponectin and the highest RBP4 quartiles were combined, the OR increased to 6.22 compared with the opposite quartiles (i.e., highest adiponectin and lowest RBP4 concentrations). Furthermore, circulating levels of adiponectin and RBP4 were significantly correlated with visceral fat and insulin resistance index. In this study, the increased prevalence of MS in elderly but relatively lean population was associated with low adiponectin and high RBP4 levels. The combination of these factors might predict older subjects at high risk for having MS.