Gene Discovery for Complex Traits: Lessons from Africa.

The genetics of African populations reveals an otherwise "missing layer" of human variation that arose between 100,000 and 5 million years ago. Both the vast number of these ancient variants and the selective pressures they survived yield insights into genes responsible for complex traits in all populations.

From genetics to biology: advancing mental health research in the Genomics ERA.

The Genomics Workgroup of the National Advisory Mental Health Council (NAMHC) recently issued a set of recommendations for advancing the NIMH psychiatric genetics research program and prioritizing subsequent follow-up studies. The report emphasized the primacy of rigorous statistical support from properly designed, well-powered studies for pursuing genetic variants robustly associated with disease. Here we discuss the major points NIMH program staff consider when assessing research applications based on common and rare variants, as well as genetic syndromes, associated with psychiatric disorders. These are broad guiding principles for investigators to consider prior to submission of their applications. NIMH staff weigh these points in the context of reviewer comments, the existing literature, and current investments in related projects. Following the recommendations of the NAMHC, statistical strength and robustness of the underlying genetic discovery weighs heavily in our funding considerations as does the suitability of the proposed experimental approach. We specifically address our evaluation of applications motivated in whole, or in part, by an association between human DNA sequence variation and a disease or trait relevant to the mission of the NIMH.

The Effect of Cellular Stress on T and B Cell Memory Pathways in Immunized and Unimmunized BALB/c Mice.

Immunological memory is a fundamental function of vaccination. The antigenic breakdown products of the vaccine may not persist, and undefined tonic stimulation has been proposed to maintain the specific memory. We have suggested that cellular stress agents to which the immune cells are constantly exposed may be responsible for tonic stimulation. Here we have studied four stress agents: sodium arsenite, an oxidative agent; Gramicidin, eliciting K(+) efflux and calcium influx; dithiocarbamate, a metal ionophore; and aluminum hydroxide (alum), an immunological adjuvant. The aims of this study are to extend these investigations to T and B cell responses of unimmunized and ovalbumin (OVA)-immunized BALB/c mice, and furthermore, to ascertain whether stress is involved in optimal expression of memory B cells, as demonstrated in CD4(+) T cells. Examination of the homeostatic pathway defined by IL-15/IL-15R (IL-15 receptor) interaction and the inflammasome pathway defined by the IL-1-IL-1R interaction between dendritic cells (DC) and CD4(+) T cells suggests that both pathways are involved in the development of optimal expression of CD4(+)CD45RO(+) memory T cells in unimmunized and OVA-immunized BALB/c mice. Furthermore, significant direct correlation was found between CD4(+)CD44(+) memory T cells and both IL-15 of the homeostatic and IL-1ß of the inflammasome pathways. However, CD19(+)CD27(+) memory B cells in vivo seem to utilize only the IL-15/IL-15R homeostatic pathway, although the proliferative responses are enhanced by the stress agents. Altogether, stress agents may up-regulate unimmunized and OVA-immunized CD4(+)CD44(+) memory T cells by the homeostatic and inflammasome pathways. However, the CD19(+)CD27(+) memory B cells utilize only the homeostatic pathway.

Stress-activated Dendritic Cells (DC) Induce Dual Interleukin (IL)-15- and IL1ß-mediated Pathways, Which May Elicit CD4+ Memory T Cells and Interferon (IFN)-stimulated Genes.

The prevailing evidence suggests that immunological memory does not require antigenic re-stimulation but is maintained by low level tonic stimulation. We examined the hypothesis that stress agents contribute to tonic cellular activation and maintain immunological memory. Stimulation of monocyte-derived dendritic cells (DC) with stress agents elicits reactive oxygen species and HSP70. NFκB is activated, which up-regulates membrane-associated (ma) IL-15, caspase-1 and IL-1ß. Co-culture of stress-treated DC with mononuclear cells activates IL-15 and IL-1ß receptors on CD4(+) T cells, eliciting CD40L, proliferation, and up-regulation of CD45RO(+) memory T cells. The transcription factors Tbet(high) and RORγt are up-regulated, whereas FoxP3 is down-regulated, resulting in enhanced Th1 and Th17 expression and the corresponding cytokines. The interaction between maIL-15 expressed by DC and IL-15R on CD4(+) T cells results in one pathway and the corresponding cells expressing IL-1ß and IL1ßR as a second pathway. Importantly, inhibition studies with IL-15 antibodies and IL-1ßR inhibitor suggest that both pathways may be required for optimum CD4(+) CD45RO(+) memory T cell expression. Type 1 IFN expression in splenic CD11c DC of stress-treated mice demonstrated a significant increase of IFN-α in CD11c CD317(+) and CD8α(+) DC. Analysis of RNA in human CD4(+) memory T cells showed up-regulation of type 1 IFN-stimulated genes and inhibition with histone methyltransferase inhibitor. We suggest the paradigm that stress-induced tonic stimulation might be responsible for the robust persistence of the immune response in vaccination and that epigenetic changes are involved in maintaining CD4(+) T cell memory.

A mechanism for controlled access to GWAS data: experience of the GAIN Data Access Committee.

The Genetic Association Information Network (GAIN) Data Access Committee was established in June 2007 to provide prompt and fair access to data from six genome-wide association studies through the database of Genotypes and Phenotypes (dbGaP). Of 945 project requests received through 2011, 749 (79%) have been approved; median receipt-to-approval time decreased from 14 days in 2007 to 8 days in 2011. Over half (54%) of the proposed research uses were for GAIN-specific phenotypes; other uses were for method development (26%) and adding controls to other studies (17%). Eight data-management incidents, defined as compromises of any of the data-use conditions, occurred among nine approved users; most were procedural violations, and none violated participant confidentiality. Over 5 years of experience with GAIN data access has demonstrated substantial use of GAIN data by investigators from academic, nonprofit, and for-profit institutions with relatively few and contained policy violations. The availability of GAIN data has allowed for advances in both the understanding of the genetic underpinnings of mental-health disorders, diabetes, and psoriasis and the development and refinement of statistical methods for identifying genetic and environmental factors related to complex common diseases.

Effect of vaginal immunization with HIVgp140 and HSP70 on HIV-1 replication and innate and T cell adaptive immunity in women.

The international effort to prevent HIV-1 infection by vaccination has failed to develop an effective vaccine. The aim of this vaccine trial in women was to administer by the vaginal mucosal route a vaccine consisting of HIV-1 gp140 linked to the chaperone 70-kDa heat shock protein (HSP70). The primary objective was to determine the safety of the vaccine. The secondary objective was to examine HIV-1 infectivity ex vivo and innate and adaptive immunity to HIV-1. Protocol-defined female volunteers were recruited. HIV-1 CN54gp140 linked to HSP70 was administered by the vaginal route. Significant adverse reactions were not detected. HIV-1 was significantly inhibited ex vivo in postimmunization CD4(+) T cells compared with preimmunization CD4(+) T cells. The innate antiviral restrictive factor APOBEC3G was significantly upregulated, as were CC chemokines which induce downregulation of CCR5 in CD4(+) T cells. Indeed, a significant inverse correlation between the proportion of CCR5(+) T cells and the concentration of CCL-3 or CCL-5 was found. Importantly, the upregulation of APOBEC3G showed a significant inverse correlation, whereas CCR5 exhibited a trend to correlate with inhibition of HIV-1 infection (r = 0.51). Furthermore, specific CD4(+) and CD8(+) T cell proliferative responses were significantly increased and CD4(+) T cells showed a trend to have an inverse correlation with the viral load (r = -0.60). However, HIVgp140-specific IgG or IgA antibodies were not detected. The results provide proof of concept that an innate mechanism consisting of CC chemokines, APOBEC3G, and adaptive immunity by CD4 and CD8 T cells might be involved in controlling HIV-1 infectivity following vaginal mucosal immunization in women. (This study has been registered at ClinicalTrials.gov under registration no. NCT01285141.) Importance: Vaginal immunization of women with a vaccine consisting of HIVgp140 linked to the 70-kDa heat shock protein (HSP70) elicited ex vivo significant inhibition of HIV-1 replication in postimmunization CD4(+) T cells compared with that in preimmunization peripheral blood mononuclear cells. There were no significant adverse events. The vaccine induced the significant upregulation of CC chemokines and the downmodulation of CCR5 expression in CD4(+) T cells, as well as an inverse correlation between them. Furthermore, the level of CCR5 expression was directly correlated with the viral load, consistent with the protective mechanism in which a decrease in CCR5 molecules on CD4(+) T cells decreases HIV-1 envelope binding. Expression of the antiviral restriction factor APOBEC3G was inversely correlated with the viral load, suggesting that it may inhibit intracellular HIV-1 replication. Both CD4(+) and CD8(+) T cells showed HIVgp140- and HSP70-specific proliferation. A strong inverse correlation between the proportion of CC chemokine-modulated CCR5-expressing CD4(+) T cells and the stimulation of CD4(+) or CD8(+) T cell proliferation by HIVgp140 was found, demonstrating a significant interaction between innate and adaptive immunity. This is the first clinical trial of vaginal immunization in women using only HIVgp140 and HSP70 administered by the mucosal route (3 times) in which a dual innate protective mechanism was induced and enhanced by significant adaptive CD4(+) and CD8(+) T cell proliferative responses.

The value of regenotyping older linkage data sets with denser marker panels.

OBJECTIVES: Linkage analysis can help determine regions of interest in whole-genome sequence studies. However, many linkage studies rely on older microsatellite (MSAT) panels. We set out to determine whether results would change if we regenotyped families using a dense map of SNPs. METHODS: We selected 47 Hispanic-American families from the NIMH Repository and Genomics Resource (NRGR) schizophrenia data repository. We regenotyped all individuals with DNA available from the NRGR on the Affymetrix Lat Array. After optimizing SNP selection for inclusion on the linkage map, we compared information content (IC) and linkage results using MSAT, SNP and MSAT+SNP maps. RESULTS: As expected, SNP provided a higher average IC (0.78, SD 0.03) than MSAT (0.51, SD 0.10) in a direct 'apples-to-apples' comparison using only individuals genotyped on both platforms; while MSAT+SNP provided only a slightly higher IC (0.82, SD 0.03). However, when utilizing all available individuals, including those who had genotypes available on only one platform, the IC was substantially increased using MSAT+SNP (0.76, SD 0.05) compared to SNP (0.61, SD 0.02). Linkage results changed appreciably between MSAT and MSAT+SNP in terms of magnitude, rank ordering and localization of peaks. CONCLUSIONS: Regenotyping older family data can substantially alter the conclusions of linkage analyses.

Susceptibility of hepato-splanchnic perfusion to intra-abdominal pressure in peritoneal dialysis patients.

BACKGROUND: The impact of peritoneal filling on hepato-splanchnic perfusion during peritoneal dialysis has not been fully elucidated yet. METHODS: Measurements were done in 20 prevalent peritoneal dialysis patients during a peritoneal equilibration test (PET) with 2L of standard dialysate. Data were obtained in the drained state at baseline (T0), after instillation (T1), and after 2 h of dwell time (T2). Intra-abdominal pressure (IAP) was measured by Durand's approach. The hepatic clearance index (KI) of indocyanine-green (ICG) was determined as an indirect measure of hepato-splanchnic blood flow. Cardiac index (CI), heart rate (HR), and total peripheral resistance index (TPRI) were derived from continuous arterial pulse analysis. Fluid volume overload (VO) was evaluated by multifrequency bioimpedance analysis. Ejection fraction (EF) was obtained from echocardiographic examination. RESULTS: IAP was 5.8 ± 3.5 mmHg at baseline (T0), rose to 9.4 ± 2.8 mmHg after instillation of dialysate (T1), and further to 9.7 ± 2.8 mmHg after 2 h of dwell time (p < 0.001). KI slightly declined from 0.60 ± 0.22 L/min/m2 at T0 to 0.53 ± 0.15 L/min/m2 at T1 (p = 0.075), and returned to 0.59 ± 0.22 L/min/m2 at T2 (p = 0.052). CI, HR, and TPRI did not change significantly. In five patients with an EF < 40% KI was significantly lower at T1 (0.42 ± 0.12 L/min/m2; p = 0.039), and further decreased at T2 (0.40 ± 0.04 L/min/m2; p = 0.016) compared to patients with normal EF (T1: 0.58 ± 0.15 L/min/m2 and T2: 0.67 ± 0.22 L/min/m2). CONCLUSIONS: Overall, hepatic clearance of ICG as a marker of hepato-splanchnic blood flow is not affected by the filling of the peritoneal cavity.

Ultra-secure storage and analysis of genetic data for the advancement of precision medicine.

Cloud computing provides the opportunity to store the ever-growing genotype-phenotype data sets needed to achieve the full potential of precision medicine. However, due to the sensitive nature of this data and the patchwork of data privacy laws across states and countries, additional security protections are proving necessary to ensure data privacy and security. Here we present SQUiD, a secure queryable database for storing and analyzing genotype-phenotype data. With SQUiD, genotype-phenotype data can be stored in a low-security, low-cost public cloud in the encrypted form, which researchers can securely query without the public cloud ever being able to decrypt the data. We demonstrate the usability of SQUiD by replicating various commonly used calculations such as polygenic risk scores, cohort creation for GWAS, MAF filtering, and patient similarity analysis both on synthetic and UK Biobank data. Our work represents a new and scalable platform enabling the realization of precision medicine without security and privacy concerns.

Omics Approaches to Investigate the Pathogenesis of Suicide.

Suicide is the second leading cause of death in U.S. adolescents and young adults and is generally associated with a psychiatric disorder. Suicidal behavior has a complex etiology and pathogenesis. Moderate heritability suggests genetic causes. Associations between childhood and recent life adversity indicate contributions from epigenetic factors. Genomic contributions to suicide pathogenesis remain largely unknown. This article is based on a workshop held to design strategies to identify molecular drivers of suicide neurobiology that would be putative new treatment targets. The panel determined that while bulk tissue studies provide comprehensive information, single-nucleus approaches that identify cell type-specific changes are needed. While single-nuclei techniques lack information on cytoplasm, processes, spines, and synapses, spatial multiomic technologies on intact tissue detect cell alterations specific to brain tissue layers and subregions. Because suicide has genetic and environmental drivers, multiomic approaches that combine cell type-specific epigenome, transcriptome, and proteome provide a more complete picture of pathogenesis. To determine the direction of effect of suicide risk gene variants on RNA and protein expression and how these interact with epigenetic marks, single-nuclei and spatial multiomics quantitative trait loci maps should be integrated with whole-genome sequencing and genome-wide association databases. The workshop concluded with a recommendation for the formation of an international suicide biology consortium that will bring together brain banks and investigators with expertise in cutting-edge omics technologies to delineate the biology of suicide and identify novel potential treatment targets to be tested in cellular and animal models for drug and biomarker discovery to guide suicide prevention.

A comparative study of stress-mediated immunological functions with the adjuvanticity of alum.

The efficacy of a vaccine is generally dependent on an adjuvant, which enhances the immune functions and alum has been widely used in human immunization. Alum activates the intracellular stress sensors inflammasomes, but whether these are responsible for the adjuvanticity is controversial. The objectives of this investigation were to examine the hypothesis that alum-mediated adjuvanticity is a function of stress and conversely that stress agents will elicit adjuvanticity. The investigation was carried out in BALB/c mice by SC immunization with ovalbumin (OVA) mixed with alum. This elicited inflammasomes, with significant activation of caspase 1, production of IL-1ß, and adjuvanticity, demonstrated by enhancing OVA-specific serum IgG antibodies, CD4(+) T cells, and proliferation. The novel finding that alum induced HSP70 suggests that stress is involved in the mechanism of adjuvanticity. This was confirmed by inhibition studies with PES (phenylethynesulfonamide), which disrupts inducible HSP70 function, and inhibited both inflammasomes and the adjuvant function. Parallel studies were pursued with an oxidative agent (sodium arsenite), K-releasing agent (Gramicidin) and a metal ionophore (dithiocarbamate). All 3 stress agents induced HSP70, inflammasomes, and the adjuvant functions. Furthermore, up-regulation of membrane associated IL-15 on DC and CD40L on T cells in the animals treated with alum or the stress agents mediate the interactions between splenic CD11c DC and CD4(+) or CD8(+) T cells. The results suggest that the three stress agents elicit HSP70, a hallmark of stress, as well as inflammasomes and adjuvanticity, commensurate with those of alum, which may provide an alternative strategy in developing novel adjuvants.

B-cell agonists up-regulate AID and APOBEC3G deaminases, which induce IgA and IgG class antibodies and anti-viral function.

B cells express two critical deaminases in the development of adaptive and innate immunity. Activation-induced cytidine deaminase (AID) functions in class switch recombination, somatic hypermutation and may result in affinity maturation of antibodies. Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G; A3G) is an innate anti-retroviral factor that inhibits HIV replication. We have studied a number of B-cell agonists with the aim of identifying the most effective agents that will up-regulate both deaminases and thereby enhance adaptive and innate immunity. CD40 ligand (CD40L) with interleukin-4 or HLA-class II antibodies significantly up-regulated both AID and A3G in isolated human CD19(+) B cells. The functions of these deaminases were demonstrated by enhancement of B-cell surface expression of IgA and IgG and inducing significantly higher IgA and IgG4 antibodies. An enhanced A3G function was then demonstrated by inhibition of HIV-1 replication in co-culture of CD4(+) T cells with autologous B cells, treated with CD40L and CD4 or HLA antibodies, compared with unstimulated human B cells. The dual B-cell-induced deaminase functions may be critical in IgA and IgG antibodies inhibiting pre-entry and A3G that of post-entry HIV-1 transmission and suggests a novel strategy of immunization, especially relevant to mucosal infections.

Immunization with recombinant macaque major histocompatibility complex class I and II and human immunodeficiency virus gp140 inhibits simian-human immunodeficiency virus infection in macaques.

Genetic, epidemiological and experimental evidence suggest that the major histocompatibility complex (MHC) is critical in controlling human immunodeficiency virus (HIV) infection. The objectives of this study were to determine whether novel recombinant Mamu MHC constructs would elicit protection against rectal challenge with heterologous simian-human immunodeficiency virus (SHIV) strain SF162.P4 in rhesus macaques. Mamu class I and II gene products were linked together with HIV gp140, simian immunodeficiency virus (SIV) p27 and heat-shock protein 70 to dextran. The vaccine was administered to two groups, each consisting of nine macaques, either subcutaneously (SC), or rectally and boosted by SC immunization. The controls were untreated or adjuvant-treated animals. Repetitive rectal challenges with up to ten doses of SHIV SF162.P4 showed a significant decrease in the peak and sequential viral RNA concentrations, and three macaques remained uninfected, in the nine SC-immunized animals, compared with infection in all nine controls. Macaques immunized rectally followed by SC boosters showed a less significant decrease in both sequential and peak viral loads compared with the SC-immunized animals, and all were infected following rectal challenge with SHIV SF162.P4. Plasma and mucosal IgG and IgA antibodies to Mamu class I alleles and HIV gp120, as well as to RANTES (regulated upon activation, normal T-cell expressed, and secreted; CCR5) were increased, and showed significant inverse correlations with the peak viral load. These results suggested that allo-immunization with recombinant MHC constructs linked to HIV-SIV antigens merits further investigation in preventing HIV-1 infection.

Immunization with recombinant HLA classes I and II, HIV-1 gp140, and SIV p27 elicits protection against heterologous SHIV infection in rhesus macaques.

Major histocompatibility complex (MHC) molecules expressed on the surface of human immunodeficiency virus (HIV) are potential targets for neutralizing antibodies. Since MHC molecules are polymorphic, nonself MHC can also be immunogenic. We have used combinations of novel recombinant HLA class I and II and HIV/simian immunodeficiency virus (SIV) antigens, all linked to dextran, to investigate whether they can elicit protective immunity against heterologous simian/human immunodeficiency virus (SHIV) challenge in rhesus macaques. Three groups of animals were immunized with HLA (group 1, n = 8), trimeric YU2 HIV type 1 (HIV-1) gp140 and SIV p27 (HIV/SIV antigens; group 2, n = 8), or HLA plus HIV/SIV antigens (group 3, n = 8), all with Hsp70 and TiterMax Gold adjuvant. Another group (group 4, n = 6) received the same vaccine as group 3 without TiterMax Gold. Two of eight macaques in group 3 were completely protected against intravenous challenge with 18 50% animal infective doses (AID(50)) of SHIV-SF162P4/C grown in human cells expressing HLA class I and II lineages represented in the vaccine, while the remaining six macaques showed decreased viral loads compared to those in unimmunized animals. Complement-dependent neutralizing activity in serum and high levels of anti-HLA antibodies were elicited in groups 1 and 3, and both were inversely correlated with the plasma viral load at 2 weeks postchallenge. Antibody-mediated protection was strongly supported by the fact that transfer of pooled serum from the two challenged but uninfected animals protected two naïve animals against repeated low-dose challenge with the same SHIV stock. This study demonstrates that immunization with recombinant HLA in combination with HIV-1 antigens might be developed into an alternative strategy for a future AIDS vaccine.

Stress-activated dendritic cells interact with CD4+ T cells to elicit homeostatic memory.

Evidence is presented that thermal or oxidizing stress-activated DC interact with CD4(+) T cells to induce and maintain a TCR-independent homeostatic memory circuit. Stress-activated DC expressed endogenous intra-cellular and cell surface HSP70. The NF-kappaB signalling pathway was activated and led to the expression of membrane-associated IL-15 molecules. These interacted with the IL-15 receptor complex on CD4(+) T cells, thus activating the Jak3 and STAT5 phosphorylation signalling pathway to induce CD40 ligand expression, T-cell proliferation and IFN-gamma production. CD40 ligand on CD4(+) T cells in turn re-activated CD40 molecules on DC, inducing DC maturation and IL-15 expression thereby maintaining the feedback circuit. The proliferating CD4(+) T cells were characterized as CD45RA(-) CD62L(+) central memory cells, which underwent homeostatic proliferation. The circuit is independent of antigen and MHC-class-II-TCR interaction as demonstrated by resistance to TCR inhibition by ZAP70 inhibitor or MHC-class II antibodies. These findings suggest that stress can activate a DC-CD4(+) T-cell interacting circuit, which may be responsible for maintaining a homeostatic antigen-independent memory.

Defining the Core Skills and Activities of the Attending Physician in Post-Acute and Long-Term Care.

The American Board of Post-Acute and Long-Term Care Medicine (ABPLM) contracted with a psychometric firm to perform a 3-phase Job Analysis following best practices. Literature was reviewed, a task force of subject matter experts was convened, a survey was developed and sent via Survey Monkey to attending physicians practicing in post-acute and long-term care settings (PALTC). The task force refined a comprehensive list of the tasks, knowledge, and medical knowledge needed in the role of attending physician in PALTC. These items were written as statements and edited until consensus was reached on their accuracy, conciseness, and lack of overlap. Task statements described distinct, identifiable, and specific practice-related activities relevant across multiple care settings. Knowledge statements described previously acquired information considered necessary to effectively perform such tasks. The survey consisted of 260 items, including 21 demographic questions, 115 task statements, 73 knowledge statements, and 72 medical knowledge statements. The survey was disseminated via e-mail invitations to Society for Post-Acute and Long-Term Care (AMDA) members and through an online link available through ABPLM's website. A total of 389 respondents participated. Survey data were analyzed with statistical analysis software SPSS. For each task and knowledge statement, an Overall Task Rating and Knowledge Rating were developed by combining the importance rating weighted at 65% and (for task) the frequency rating or (for knowledge) the cognitive level weighted at 35%. One task statement and 1 medical knowledge statement had a mean importance rating lower than 2.5 and were dropped from further review, resulting in a final count of 114 task, 73 knowledge, and 71 medical knowledge statements (258 total). The results of this Job Analysis highlight the unique and specific nature of medical care provided by attending physicians across a range of PALTC settings. These findings lay a foundation for Focused Practice Designation or Subspecialty in PALTC and changes in practice and policy.

The epidemiology of psychiatric disorders in Africa: a scoping review.

This scoping review of population-based epidemiological studies was done to provide background information on the prevalences and distribution of psychiatric disorders in Africa for calls to broaden diversity in psychiatric genetic studies. We searched PubMed, EMBASE, and Web of Science to retrieve relevant literature in English, French, and Portuguese from Jan 1, 1984, to Aug 18, 2020. In 36 studies from 12 African countries, the lifetime prevalence ranged from 3·3% to 9·8% for mood disorders, from 5·7% to 15·8% for anxiety disorders, from 3·7% to 13·3% for substance use disorders, and from 1·0% to 4·4% for psychotic disorders. Although the prevalence of mood and anxiety disorders appears to be lower than that observed in research outside the continent, we identified similar distributions by gender, although not by age or urbanicity. This review reveals gaps in epidemiological research on psychiatric disorders and opportunities to leverage existing epidemiological and genetic research within Africa to advance our understanding of psychiatric disorders. Studies that are methodologically comparable but diverse in geographical context are needed to advance psychiatric epidemiology and provide a foundation for understanding environmental risk in genetic studies of diverse populations globally.

Cytoskeletal proteins bound to heat-shock protein 70 may elicit resistance to simian immunodeficiency virus infection of CD4(+) T cells.

This study is based on the evidence that immunization of macaques with human CD4(+) T cells elicits prevention of simian immunodeficiency virus (SIV) infection. We hypothesized that heat-shock protein 70 (HSP70) isolated from CD4(+) T cells may act as a chaperone and carry the protective host proteins. Two moieties of HSP70 were affinity-purified from human CD4(+) T cells; an ADP preparation with HSP70-bound proteins (ADP-HSP) and an ATP control preparation. Immunization of rhesus macaques with these preparations showed significant inhibition of SIVmac251 infectivity ex vivo in CD4(+) T cells only with the ADP-HSP (P = 0.01). Proteomic analysis identified three cytoskeletal elements, cofilin, profilin and gamma-actin, exclusively in the ADP-HSP preparation. Investigation of the mechanism of prevention of SIV replication suggests that antibodies to the cytoskeletal proteins may inhibit actin depolymerization and facilitate viral degradation by the innate antiviral APOBEC3G. As cytoskeletal proteins are critical in the formation of virological and immunological synapses, finding specific antibodies and anti-SIV/human immunodeficiency virus (HIV) factors suggests a novel insight into HIV-1 immunopathogenesis.

The effect of allogeneic in vitro stimulation and in vivo immunization on memory CD4(+) T-cell APOBEC3G expression and HIV-1 infectivity.

Allogeneic immunity is one of the most potent natural immune responses. APOBEC3G (A3G) is an intracellular anti-viral factor that deaminates cytidine to uridine. Allogeneic stimulation of human CD4(+) T cells in vitro upregulated A3G mRNA and a significant correlation was found between the mixed leukocyte reaction and A3G mRNA. The mechanism of upregulation of A3G mRNA involves interaction between HLA on DC and TCR of CD4(+) T cells, which is ZAP70 and downstream ERK phosphokinase signalling dependent and induces CD40L and A3G mRNA expression in CD4(+) T cells. Alloimmune-induced A3G was found to be significantly increased in CD45RA(-), CCR5(+) and CD45RA(-)CCR7(-) subsets of effector memory T cells. In vivo studies of women alloimmunized with their partners' PBMC also showed a significant increase in A3G protein in CD4(+) T cells, CD45RO(+) memory and CCR7(-) effector memory T cells. The functional effect of allostimulation upregulating A3G mRNA was demonstrated by a significant decrease in in vitro infectivity, using GFP-labelled pseudovirus and confirmed by a decrease in HIV-1 (BaL) infection of primary CD4(+) T cells. The results suggest that alloimmunization offers an alternative or complementary strategy in inducing an innate anti-viral factor that inhibits HIV-1 infection.