Search

Background: The chronic fatigue syndrome (CFS) is characterized by post-exertional malaise and fatigue. We designed this pilot study to explore whether the illness was associated with alterations in immunological markers following exercise. Methods: We measured immunological markers before and up to three days after either a sub-maximal or maximal bicycle exercise test.We studied nine patients with CFS and nine ageand sex-matched healthy but sedentary controls. We also studied the same patients with CFS at home after a night's sleep and then after traveling to the study center. Results: There were no significant differences in any of the cell markers after a sub-maximal exercise test compared to a maximal test. However, we found elevated concentrations of plasma transforming growth factor beta (TGF-ß), even before exercise, in subjects with CFS (median (IQR) of 904 (182-1072) pg/ml) versus controls (median (IQR) of 50 (45-68) pg/ml) (P < .001). Traveling from home to the hospital significantly elevated TGF-ß concentrations from a resting median (IQR) concentration of 1161 (130-1246) pg/ml to a median (IQR) concentration of 1364 (1155-1768) pg/ml (P < .02). There was also a sustained increase in plasma tumor necrosis factor alpha (TNF-alpha) after exercise in CFS patients, but not in controls (P = .004 for the area under the curve), although traveling had no such effect. CD3, CD4 and HLA DR-expressing lymphocyte counts were lower in CFS patients, but exercise had the same effect in both groups, causing an immediate increase in circulating cell numbers that lasted less than three hours. Conclusions: These results suggest that the relationship between physical activity and both pro-inflammatory and anti-inflammatory cytokines merits further investigation in patients with CFS. The results also emphasize the importance of defining a truly resting baseline condition in such studies. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to develop and pilot the Clinical High Risk for Psychosis Services Fidelity Scale (CHRPS-FS)., Methods: A literature review was conducted to identify evidence-based treatments for individuals at clinical high risk for psychosis (CHRP). These findings were compared with the First-Episode Psychosis Services Fidelity Scale (FEPS-FS). Common items were retained, and others were added, modified, or deleted. Next, the Delphi process was conducted with 17 clinical and academic experts in CHRP care to determine consensus on the importance and validity of each item. Concurrently, the preliminary tool was piloted in eight coordinated specialty care (CSC) clinics serving individuals with CHRP., Results: The literature review identified two components of CHRP care that were not detailed in the FEPS-FS and were added to the CHRPS-FS; furthermore, one FEPS-FS item was modified and six were removed. In the Delphi process, clinical and academic experts achieved a consensus of >80% in two rounds, with some changes in item wording and the addition of one item (stepped care approach). A CHRPS-FS assessment was successfully piloted in eight CSC clinics. The mean CHRPS-FS rating score was 3.96 (range 3.75-4.23), and the median proportion of items rated at good to high fidelity was 72% (range 66%-78%)., Conclusions: The CHRP-FS is feasible to implement, has face validity based on expert consensus, can be completed in conjunction with a FEPS-FS assessment or alone, and captures variability across programs. The CHRPS-FS measures service delivery and is suitable for clinical trials, learning health care systems, and quality improvement efforts., Competing Interests: Ms. Nye reports having been a paid consultant for ChatOwl Inc., a digital mental health company. Dr. Niendam reports being a cofounder of and shareholder in Safari Health Inc., a digital mental health company. The other authors report no financial relationships with commercial interests.

Despite the substantial capacity of qualitative and mixed methods research to advance healthcare and interventions knowledge, most large-scale health intervention trials exclusively use quantitative methods. The authors argue that qualitative research can optimize investments in these studies. As researchers within the Early Psychosis Intervention Network (EPINET), the authors highlight examples of how qualitative research has enhanced this national initiative, organizing them with a Learning Health System (LHS) framework to demonstrate the ways qualitative research can increase value at each phase of a health trial. They emphasize the critical need for integrating qualitative research from the beginning of health trials, ensuring its influence in decision-making, creating infrastructure to support it, and promoting meaningful representation within research teams. By illustrating the advantages of qualitative research in EPINET, they advocate for sustained commitment to qualitative research in health trials to maximize value in client and provider experience, cost, and population health., Competing Interests: Declarations. Consent for Publication: This paper does not use any original data. We have not been paid to write this article by a pharmaceutical company or other agency. All authors accept responsibility to submit for publication., (© 2025. The Author(s).)

Using data collected in routine care delivery to inform treatment is a key feature of a learning health system (LHS). In this study, we explored the experiences of service users and providers adopting measurement-based care (MBC) in early psychosis (EP) specialty care settings. Qualitative interviews were conducted with 32 providers and 12 service users across 18 programs in the Early Psychosis Intervention Network of California (EPI-CAL). These findings were compared with quantitative data from Beehive, EPI-CAL's data collection and review application. Regarding the clinical benefits of MBC in EP, three broad themes were identified - supporting safety monitoring and response, the assessment process, and delivery of psychotherapy. Outside of direct clinical care, Beehive was considered to support clinical supervision and external reporting, while service users reported data collection facilitated self-reflection. In the quantitative Beehive application data collected from 23 EP programs, high utilization of the safety alert system was evident (349 alerts in total, of which 338 [96.85 %] were resolved at a median of 2.03 days). However, service users' key survey data was only reviewed by assigned providers in 32.22 % (142 of 441) of cases. While providers and service users saw many benefits to Beehive, utilization was highly inconsistent outside of the alert system. Going forward, further consideration of how best to support EP providers to consistently use data in care is necessary to maximize the utility of the LHS approach and positively impact outcomes., Competing Interests: Declaration of competing interest Tara A. Niendam is a cofounder and shareholder in Safari Health, Inc. No other authors disclosed any competing interests., (Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: A prolonged first episode of psychosis (FEP) without adequate treatment is a predictor of poor clinical, functional, and health outcomes and significant economic burden. Team-based "coordinated specialty care" (CSC) for early psychosis (EP) has established effectiveness in promoting clinical and functional recovery. However, California's CSC program implementation has been unsystematic and could benefit from standardizing its processes and data collection infrastructure. To address this, we established a consortium of EP clinics across the state via a Learning Health Care Network (LHCN) framework to develop the Early Psychosis Intervention Network of California (EPI-CAL). EPI-CAL's LHCN developed a core battery of evidence-based measures for service users and family members and linked them together using a unique data collection and visualization application, Beehive., Methods and Objectives: EPI-CAL's LHCN collects, visualizes, and aggregates data at the individual and clinic level for EP programs across California via Beehive. Beehive was designed to: (1) collect outcomes data from service users receiving care at EP programs and their support persons, (2) provide the data to providers on a secure web-based dashboard to support measurement-based care, and (3) allow data to be used for program or research analysis. We will (1) determine the feasibility of implementing an LHCN across a diverse, decentralized network of early psychosis programs, (2) determine if the implementation of an LHCN increases the delivery of measurement-based care, and (3) determine if the implementation of measurement-based care is associated with significant improvements in key service user outcomes. EPI-CAL's network will contribute data to the Early Psychosis Intervention Network (EPINET) program., Discussion: The current study aims to establish an LHCN of EP clinics in California that implements harmonized data collection using Beehive and assesses the feasibility of establishing such a network. Our goal is for this harmonized data collection approach to be used to inform decisions and develop learning opportunities for service users, staff, and administrators, and to improve outcomes for service users and their supporters in CSC care. Further, the data will enable programs and research teams to examine what elements of care lead to program success and improved treatment outcomes for service users., Clinical Trials Registration: www., Clinicaltrials: gov , identifier NCT04007510; registered 07/05/2019., Competing Interests: Declarations Ethics approval and consent to participate The University of California, Davis Institutional Review Board approved the study (1403828-21, California Collaborative Network to Promote Data-Driven Care and Improve Outcomes in Early Psychosis [CORE]). Additionally, several of the counties and universities with a program participating in EPI-CAL required a separate review and approval of the project by their institutional review board (e.g., Los Angeles County Department of Mental Health Human Subjects Research Committee; San Mateo County Behavioral Health and Recovery Services Institutional Review Board; Sacramento County Department of Health and Human Services Research Review Committee; Napa County Institutional Review Board; County of San Diego Behavioral Health Services Research Review Board; and Orange County Health Care Agency Human Subjects Review Committee) or compliance or oversight departments. Multisite/single IRB with reliance from UCSD and UCSF on UC Davis IRB. Associated IRB protocols include 1411596-5 (UCD), 1411602-2 (UCSD), 1411601-5 (UCSF). Competing interests Tara A. Niendam is a cofounder and shareholder in Safari Health, Inc. No other authors disclosed any competing interests., (© 2024. The Author(s).)

Objective: Learning health care networks can significantly improve the effectiveness, consistency, and cost-effectiveness of care delivery. As part of a data harmonization process, incorporation of the perspectives of community partners to maximize the relevance and utility of the data is critical., Methods: A mixed-methods focus group study was conducted with early psychosis program providers, leadership, service users, and family members to explore their priorities regarding data collection in early psychosis care. Focus group transcripts were analyzed through thematic analysis., Results: Twenty-two focus groups comprising 178 participants were conducted across 10 early psychosis programs. Participants considered functioning, quality of life, recovery, and symptoms of psychosis as key outcomes to assess, although variation by participants' roles was also evident. Participants emphasized the clinical utility of assessing a broad range of predictors of care outcomes, favored a broad conceptualization of the constructs assessed, and indicated a preference for client-reported measures. Participants also emphasized the importance of surveys adopting a recovery-oriented, strengths-based approach., Conclusions: Large-scale aggregation of health care data collected as part of routine care offers opportunities for research and may have a positive impact on care delivery and quality improvement activities. However, these benefits are contingent on the data being both relevant and accessible to those who deliver and receive such care. This study highlights an approach that may inform the development of core assessment batteries used, optimizing the utility of such data for all community partners., Competing Interests: Ms. Nye serves as a consultant for ChatOwl, Inc., a digital mental health company. Dr. Niendam is founder of and a shareholder in Safari Health, Inc.

Background: Increased use of eHealth technology and user data to drive early identification and intervention algorithms in early psychosis (EP) necessitates the implementation of ethical data use practices to increase user acceptability and trust., Objective: First, the study explored EP community partner perspectives on data sharing best practices, including beliefs, attitudes, and preferences for ethical data sharing and how best to present end-user license agreements (EULAs). Second, we present a test case of adopting a user-centered design approach to develop a EULA protocol consistent with community partner perspectives and priorities., Methods: We conducted an exploratory, qualitative, and focus group-based study exploring mental health data sharing and privacy preferences among individuals involved in delivering or receiving EP care within the California Early Psychosis Intervention Network. Key themes were identified through a content analysis of focus group transcripts. Additionally, we conducted workshops using a user-centered design approach to develop a EULA that addresses participant priorities., Results: In total, 24 participants took part in the study (14 EP providers, 6 clients, and 4 family members). Participants reported being receptive to data sharing despite being acutely aware of widespread third-party sharing across digital domains, the risk of breaches, and motives hidden in the legal language of EULAs. Consequently, they reported feeling a loss of control and a lack of protection over their data. Participants indicated these concerns could be mitigated through user-level control for data sharing with third parties and an understandable, transparent EULA, including multiple presentation modalities, text at no more than an eighth-grade reading level, and a clear definition of key terms. These findings were successfully integrated into the development of a EULA and data opt-in process that resulted in 88.1% (421/478) of clients who reviewed the video agreeing to share data., Conclusions: Many of the factors considered pertinent to informing data sharing practices in a mental health setting are consistent among clients, family members, and providers delivering or receiving EP care. These community partners' priorities can be successfully incorporated into developing EULA practices that can lead to high voluntary data sharing rates., (©Laura M Tully, Kathleen E Nye, Sabrina Ereshefsky, Valerie L Tryon, Christopher Komei Hakusui, Mark Savill, Tara A Niendam. Originally published in JMIR Human Factors (https://humanfactors.jmir.org), 14.11.2023.)

Background: A growing body of literature indicates that smartphone technology is a feasible add-on tool in the treatment of individuals with early psychosis (EP) . However, most studies to date have been conducted independent of outpatient care or in a research clinic setting, often with financial incentives to maintain user adherence to the technology. Feasibility of dissemination and implementation of smartphone technology into community mental health centers (CMHCs) has yet to be tested, and whether young adults with EP will use this technology for long periods of time without incentive is unknown. Furthermore, although EP individuals willingly adopt smartphone technology as part of their treatment, it remains unclear whether providers are amenable to integrating smartphone technology into treatment protocols., Objective: This study aimed to establish the feasibility of implementing a smartphone app and affiliated Web-based dashboard in 4 community outpatient EP clinics in Northern California., Methods: EP individuals in 4 clinics downloaded an app on their smartphone and responded to daily surveys regarding mood and symptoms for up to 5 months. Treatment providers at the affiliated clinics viewed survey responses on a secure Web-based dashboard in sessions with their clients and between appointments. EP clients and treatment providers filled out satisfaction surveys at study end regarding usability of the app., Results: Sixty-one EP clients and 20 treatment providers enrolled in the study for up to 5 months. Forty-one EP clients completed the study, and all treatment providers remained in the study for their duration in the clinic. Survey completion for all 61 EP clients was moderate: 40% and 39% for daily and weekly surveys, respectively. Completion rates were slightly higher in the participants who completed the study: 44% and 41% for daily and weekly surveys, respectively. Twenty-seven of 41 (66%) EP clients who completed the study and 11 of 13 (85%) treatment providers who responded to satisfaction surveys reported they would continue to use the app as part of treatment services. Six (15%; 6/41) clients and 3 providers (23%; 3/13) stated that technological glitches impeded their engagement with the platform., Conclusions: EP clients and treatment providers in community-based outpatient clinics are responsive to integrating smartphone technology into treatment services. There were logistical and technical challenges associated with enrolling individuals in CMHCs. To be most effective, implementing smartphone technology in CMHC EP care necessitates adequate technical staff and support for utilization of the platform., (©Divya Kumar, Laura M Tully, Ana-Maria Iosif, Lauren N Zakskorn, Kathleen E Nye, Aqsa Zia, Tara Ann Niendam. Originally published in JMIR Mental Health (http://mental.jmir.org), 27.02.2018.)

Smartphone applications that promote symptom tracking and self-management may improve treatment of serious mental illness (SMI). Although feasibility has been established in chronic adult outpatient or inpatient SMI samples, no data exist regarding implementation of smartphone technology in adolescent and young adult populations as part of early psychosis (EP) outpatient care. We implemented a smartphone "app" plus clinician Dashboard as an add-on treatment tool in the University of California, Davis Early Psychosis Program. Participants completed daily and weekly surveys examining mood, symptoms, and treatment relevant factors via the app for up to 14 months. Clinicians discussed symptom ratings and surveys during regular treatment sessions using the Dashboard. We report methodological details of the study, feasibility metrics, and analyses of the validity of measuring symptoms via self-report using mobile health (mHealth) technology in comparison to gold-standard clinician-rated interviews based on a comprehensive longitudinal analysis of within-person data. Results demonstrate that integrating mHealth technology into EP care is feasible and self-report assessment of symptoms via smartphone provides symptom data comparable to that obtained via gold-standard clinician-rated assessments., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The objectives of this study were to investigate the efficacy of a prototype DNA immunization construct encoding the urease B subunit enzyme of Helicobacter pylori (H. pylori) for inducing adaptive and innate immune responses in mice immunized via intramuscular or subcutaneous routes and to further explore the adjuvant effects of the CpG motifs in the vector. Antibody, cytokine, and beta-defensin profiles were assessed in the stomachs of immunized animals: experiments were terminated 3 months after immunization because there was a significant increase in the anti-H. pylori urease B antibody response at Week 6 in mice immunized with the urease B construct. A long lasting expression of IL-10 mRNA was noted. Furthermore, a marked and sustained increase in the mRNA expression of beta-defensins was also observed, particularly beta1. This study demonstrates that an H. pylori urease B DNA construct can induce innate as well as adaptive immune responses in the stomachs of immunized mice. Upregulation of beta-defensin gene expression followed immunization and we believe that this is the first report of a DNA vaccine inducing innate anti-microbial responses. Such complex molecular interactions that modulate both innate and adaptive immune responses may be of critical importance in the control of mucosal pathogens, such as H. pylori.

The CXCR4 chemokine receptor is a G(i) protein-coupled receptor that triggers multiple intracellular signals in response to stromal cell-derived factor 1 (SDF-1), including calcium mobilization and p44/42 extracellular signal-regulated kinases (ERK1/2). Transduced signals lead to cell chemotaxis and are terminated through receptor internalization depending on phosphorylation of the C terminus part of CXCR4. Receptor endocytosis is also required for some receptors to stimulate ERK1/2 and to migrate through a chemokine gradient. In this study, we explored the role played by the 3 intracellular loops (ICL1-3) and the C terminus domain of CXCR4 in SDF-1-mediated signaling by using human embryonic kidney (HEK)-293 cells stably expressing wild-type or mutated forms of CXCR4. ICL3 of CXCR4 is specifically involved in G(i)-dependent signals such as calcium mobilization and ERK activation, but does not trigger CXCR4 internalization after SDF-1 binding, indicating that ERK phosphorylation is independent of CXCR4 endocytosis. Surprisingly, ICL2, with or without the aspartic acid, arginine, and tyrosine (DRY) motif, is dispensable for G(i) signaling. However, ICL2 and ICL3, as well as the C terminus part of CXCR4, are needed to transduce SDF-1-mediated chemotaxis, suggesting that this event involves multiple activation pathways and/or cooperation of several cytoplasmic domains of CXCR4.

The human immunodeficiency virus-1 (HIV-1) utilises CD4 and certain beta-chemokine receptors, mainly CCR-5 and CXCR4, for attachment and virus entry into T-lymphocytes and monocytes/macrophages. CD4 and beta-chemokine receptors participate in intracellular signalling via protein tyrosine kinases and G-protein-coupled signalling. The factors which influence HIV-1 replication and the intracellular signalling mechanisms elicited by the virus are not well understood. In this study, it was demonstrated that exposure of peripheral blood lymphocytes (PBLs) to a T-cell tropic strain of HIV-1 evokes signal(s) which results in downregulation of intracellular cAMP. In addition, pre-incubation of PBLs with the Gi-protein inhibitor Pertussis toxin mediated a significant inhibition of HIV-1 replication. These data strongly suggest that HIV-1 employs CD4 receptors and Gi-coupled proteins for entry into target cells and that productive HIV-1 infection is dependent on an active signalling event., (Copyright 1999 Academic Press.)

Objective: To establish the relationship between T cell responses to integrin coreceptor stimulation and B cell hyperreactivity as measured by pathologic autoantibody production., Methods: Peripheral blood mononuclear cells from 42 patients with SLE according to the American Rheumatism Association criteria were examined for their ability to adhere to plate-immobilised fibronectin. Co-stimulation assays were performed on the same cells using anti-CD3 antibody alone or co-immobilised with an anti-beta1-integrin antibody. Proliferative responses were measured by 3[H]thymidine pulsing on day 3 and activation was determined using a commercial protein kinase C assay, the protocol being established by our group in association with Promega. Beta-integrin expression was established by FACS analysis., Results: An impaired PKC response to integrin-mediated activation was found in T-lymphocytes from 6/21 (29%) SLE patients, which correlated significantly with an absence of anti-dsDNA antibody in patient sera, irrespective of prednisolone treatment. Integrin co-stimulation of TcR/CD3-induced proliferation and T cell adhesion to fibronectin were also impaired among 5/21 (24%) and 6/15 (40%) patients studied, respectively., Conclusion: We hypothesise that the integrity of beta1-integrin signalling pathways may influence pathological antibody production in SLE by affecting T-lymphocyte activation and interactions between T- and B-lymphocytes.

Proper function of the protein tyrosine phosphatase CD45 is required for the positive regulation of the activity of src tyrosine kinases p56lck and p59fyn which participate in T-cell receptor and CD4 receptor signalling. In this study, the effect of HIV-1 infection on the function of CD45-associated tyrosine phosphatase activity in the H9 T-cell line has been investigated with respect to CD3 and CD4 ligation. A significant reduction in CD45-associated phosphatase activity was observed following CD3 + CD4 ligation in virally infected cells, whereas CD45 activity was not compromised following CD3 receptor ligation. Dysfunctional CD45 activity in infected cells was not attributable to reduced receptor surface expression induced by HIV-1, since CD4, CD3 and CD45 expression levels were found to be intact. Defective CD45 activity correlated with inhibted downstream signalling events as evidenced by reduced CD4-associated tyrosine kinase activity and inhibition of PLC-gamma1. Impaired CD45 function is likely to play a critical role in the inhibition of CD3/CD4 signalling thereby contributing to HIV-1 pathogenesis., (Copyright 1998 Academic Press.)

Although circulating levels of interleukin 8 (IL-8), a potent pro-inflammatory chemokine, and many other inflammatory mediators increase in response to cardiopulmonary bypass, only a small proportion of patients develop a clinically significant systemic inflammatory response. The natural mechanisms that control the inflammatory response are poorly understood. To investigate the role of IL-8 in a human inflammatory model, 15 adult patients undergoing cardiopulmonary bypass for elective coronary artery bypass grafting were studied. Following reperfusion, plasma IL-8 levels increased significantly from 58 pg/mL (pre-bypass) and 66 pg/mL (after 20 min of bypass) to 98 pg/mL (p = .02 and .04, respectively), but this was accompanied by a concomitant threefold decrease in the IL-8 binding affinity of circulating neutrophils (Dissociation constant (KL) post-reperfusion/KL pre-bypass = 3.2; KL post-reperfusion/KL after 20 min of bypass = 2.8). IL-8-triggered release of myeloperoxidase and elastase by peripheral blood neutrophils ex vivo was also down-regulated following reperfusion. There were no significant changes in beta 2 integrin expression or inositol polyphosphate metabolism of peripheral blood neutrophils. These changes in receptor affinity and neutrophil responsiveness to IL-8 may represent an important in vivo regulatory mechanism which serves to prevent excessive tissue injury from inflammatory triggers.

We investigated the effects of early human immunodeficiency virus-1 infection (HIV-1) on CD4- and CD28-mediated co-signaling of the T cell receptor (TCR)/CD3 complex in peripheral blood lymphocytes (PBL). CD4 ligation either alone or in conjunction with TCR occupancy resulted in abrogated signaling shown by impaired co-association of the tyrosine kinase ZAP-70 with the CD3-zeta chains in virally infected PBL. In addition, down-regulation of CD4-associated TCR signaling resulted in diminished tyrosine phosphorylation of mitogen-activated protein kinase (MAPK), a serine threonine kinase which is critically involved in the regulation of transcription factors. Furthermore, these aberrant CD4-driven signals rendered HIV-1-infected PBL susceptible to activation-induced cell death. By contrast, cross-linking of the TCR/CD3 complex with the CD28 receptor improved tyrosine phosphorylation of MAPK and salvaged infected PBL from activation-induced cell death. Our data demonstrate the importance of appropriate CD3, CD4 and CD28 co-stimulatory function to prevent apoptosis. The CD4-mediated signaling defects of the TCR could contribute to the loss of immunocompetent cells during HIV-1 infection via activation-induced cell death, whereas stimulation through the CD28 pathway could reverse these detrimental effects.

HIV infection is associated with a disease status-dependent impairment of Ag-specific T cell responses, resulting in anergy or unchecked apoptotic cell death. beta1 integrins play an important role in the induction of T lymphocyte responses to antigenic challenge by providing a T cell costimulatory signal, and have been shown to rescue various cell types from undergoing apoptosis. We examined the integrin-triggered cell survival signal and associated pathways in CD3+ T cells derived from 69 HIV-1-infected individuals in comparison with healthy controls. We found beta1 integrin-mediated costimulation of TCR-induced T cell proliferation and protection from aberrant cell death to be absent in the majority of patients with AIDS, but intact in asymptomatic, infected individuals. The lack of integrin-mediated rescue may be partly due to an early impairment of TCR/integrin-costimulated secretion of IFN-gamma, a type 1 lymphokine that protects against TCR-induced apoptosis of T cells from HIV-seropositive donors, but not loss of integrin expression. The mechanism of integrin hyporesponsiveness appeared to correlate with a failure of the integrin-generated signal to induce pp125FAK mRNA and protein expression. Protein kinase C activation in CD3+ T cells following integrin stimulation was also impaired in HIV-infected individuals, mostly among the symptomatic/AIDS patients. Protein kinase C inactivation in T cells was shown to have a destabilizing effect in vitro on pp125FAK mRNA that contains an AUUUA motif in the 3'-untranslated region, a consensus sequence for the AU-rich elements responsible for mRNA destabilization. These aberrant changes in pp125FAK expression may have direct significance to the overall immunopathogenesis during infection with HIV-1.

The effect of early human immunodeficiency virus-1 infection in vitro on proximal signal transduction events in primary peripheral blood lymphocytes was investigated with respect to CD4-mediated costimulation of CD3/T cell-receptor signalling. Tyrosine phosphorylation profiles induced by CD4 and CD3 + CD4 ligation were profoundly abrogated in virally infected cells, although CD4 receptor expression remained intact during early infection. Furthermore, the association of the tyrosine kinase p56lck with the CD4 receptor was reduced in virally infected cells. The downmodulation of CD4-mediated CD3 signalling coincided with the subsequent inhibition of the activity and tyrosine phosphorylation of the downstream kinase ZAP-70 in virally infected cells. The observed virally mediated cosignalling defects during early infection may account for the inhibition of distal signal events and thus contribute to HIV pathogenesis, such as reduced immune response to antigenic exposure, anergy, and apoptosis.

Objectives: To investigate, in lymphocytes from HIV-1-infected individuals, the phenotypic expression of various adhesion co- or counter-receptors [lymphocyte function-associated antigen (LFA)-3, LFA-1 and intercellular adhesion molecule (ICAM)-1] involved in providing the co-stimulatory signal through the phospholipase C-gamma pathway in relation to inositol polyphosphate metabolism., Design and Methods: Cell adhesion molecule profiles of peripheral blood lymphocytes (PBL) from 39 HIV-1-infected individuals at various stages of infection and 20 healthy laboratory controls were studied using flow cytometry. These were studied in 14 patients with late-stage disease in conjunction with their inositol polyphosphate metabolic profiles measured by high performance liquid chromatography. Levels of HIV-1 present in cell lysates were concurrently measured by a p24 antigen capture assay. In addition, the effects of a specific anti-ICAM-1 antisense oligonucleotide on the intracellular phosphatase activities of lymphocytes from a separate group of eight HIV-1-infected individuals were examined., Results: The expression of LFA-1, a beta 2 integrin, was upregulated among patient PBL in parallel with disease progression, whereas that of LFA-3 (CD58) was found to be significantly reduced among the CD4+ lymphocyte subset in all stages of infection. The 5-phosphatase activity, which we previously observed to be defective in HIV disease, was found to correlate linearly with the expression of both LFA-1 and its ligand, ICAM-1. Treatment of patient lymphocytes with an antisense oligonucleotide, which reduced the cell surface expression of ICAM-1 by blocking the translation of its mRNA, resulted in further reduction of intracellular phosphatase activities., Conclusions: Our results suggest a pivotal role for adhesion co- and counter-receptors in influencing lymphocyte signalling and hence cellular response to recall antigens in HIV-1-infected individuals.

Inositol 1,4,5-triphosphate (IP3) and inositol 1,3,4,5-tetrakisphosphate (IP4) are calcium-regulating second messenger molecules generated following the binding of a wide range of hormones and growth factors to their receptors. The actions of these messengers, which play important roles in the regulation of cell proliferation as well as in other signaling pathways, are terminated by the action of a 5-phosphomonoesterase (5-PME) enzyme. We have assayed this enzyme in normal and malignant hemopoietic cells. Extracts from normal bone marrow cells and peripheral blood mononuclear cells (PBMNC) degraded [3H]IP3 at rates of 74.5 (+/- 3.4) and 84.5 (+/- 7.9) pmol/min/micrograms protein, respectively. PME activity in 10/13 (77%) acute lymphoblastic leukemia samples were significantly below the normal range and the enzyme was completely undetectable in three (23%) of these. Enzyme activity in 8/9 (89%) chronic lymphocytic leukemia samples were below the normal range, being undetectable in three of these (33%). Nine of 24 (38%) acute myeloid leukemia samples contained low 5-PME levels, which was undetectable in one sample. Reduced 5-PME activity was detected in 2/7 (28%) of chronic granulocytic leukemia samples. The data here are consistent with the hypothesis that a reduced rate of degradation of IP3 and IP4 in some leukemia cells may result in the aberrant operation of signaling pathways, possibly including those involved in the control of cell proliferation.

Inositol 1,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate are Ca(2+)-regulating second messenger molecules which are generated via the cleavage of inositol lipids. We have previously shown that these species are autonomously generated in HL60 myeloid leukemia cells and that they may play a role in signalling the continuous proliferation of this cell line. Here we show that the activity of the 5-phosphomonoesterase (5-PME) enzyme which cleaves and inactivates these second messengers was strikingly reduced in HL60 cells compared to normal granulocytes or macrophages. Induction of differentiation of HL60 cells along the monocyte/macrophage or granulocytic pathways did not result in a significant increase in 5-PME activity. The activity of this enzyme was also low in extracts of bone marrow mononuclear cells from four patients with myeloid leukemia. A lesion in the 5-PME pathway may therefore result in the conservation of Ca(2+)-regulating second messengers in the HL60 cell line and in some myeloid leukemia cells. It is plausible that this lesion may co-operate with the autonomous cleavage of inositol lipids in the signalling of leukemic cell proliferation.

Lymphocytes infected in vivo with HIV or lymphoblastoid cells exposed in vitro to either HIV or its envelope glycoprotein (gp120) show a defect in inositol polyphosphate-mediated signal transduction together with an associated abnormality in intracellular calcium regulation. The defect in patients reverses after treatment with the anti-retroviral agent zidovudine (AZT). We present evidence that the defect is at the level of the Ins (1,3,4,5)P4 5-phosphomonoesterase (PME) in these cells and that, though elevation of the intracellular ATP level partially down-regulates the activity of this enzyme, such changes alone are unable to account for the complete inhibition seen in HIV-infected cells.

Lymphocytes or lymphoblastoid cells that have been infected by HIV in vitro or exposed to its envelope glycoprotein (gp120) show abnormal inositol polyphosphate-mediated signal transduction and associated defects in calcium regulation. Such cells behave as though they were chronically activated and fail to respond to further activating signals. We now show that similar changes are seen in lymphocytes obtained from HIV-infected subjects at various stages of infection, despite the fact that only a minority of such cells are infected. Furthermore, the defect in the phosphatidylinositol hydrolysis pathway in lymphocytes obtained from AIDS patients reverses after treatment with zidovudine, in parallel with improvements in phytohaemagglutinin-induced proliferative response and interferon-gamma production.

Qualitative defects in immune responsiveness after human immunodeficiency virus (HIV) infection have been well characterized and may play a key role in the development of HIV disease. However, no clear picture of the underlying mechanism of the functional deficiencies has yet emerged. In this article, Anthony Pinching and Keith Nye suggest that HIV or HIV proteins can sabotage transmembrane signalling and that this is of primary importance to the alterations in immune responsiveness.

Infection with HIV causes a reduction in the numbers and function of CD4+ lymphocytes and functional abnormalities of other cells. We have studied the effect of HIV infection on signal transduction in the H9 lymphoblastoid CD4+ cell line. Resting HIV-infected H9 cells show evidence of chronic activation with raised levels of InsP3 and InsP4, the active metabolites of the inositol polyphosphate pathway, and a consequently raised intracellular free calcium concentration. Stimulation of HIV-infected H9 cells with phytohemagglutinin (PHA) leads to a fall in the previously raised levels of InsP3 but a further rise in InsP4, whilst an attenuated intracellular calcium rise is seen with both PHA and anti-CD3 antibody. The observed effects of HIV infection on signal transduction provide a mechanism to explain the functional defects in CD4+ lymphocytes and, possibly, other cell types.

The distribution of phenotypes of the group specific component (Gc) was examined in 203 homosexuals at risk of infection or infected by the human immunodeficiency virus and compared with that in 50 randomly selected homosexuals and 122 healthy male heterosexual seronegative controls. 30.2% of patients with the acquired immunodeficiency syndrome (AIDS) were homozygous for Gc 1 fast (Gc 1f) compared with 0.8% of controls (p less than 0.0001); patients with other clinical manifestations of HIV infection were also more likely than controls to have Gc 1f. By contrast, seronegative symptomless homosexual contacts of AIDS patients (AH-p) lacked this phenotype but were more likely than controls to be homozygous for Gc 2 (25% vs 9%, p less than 0.05). AIDS patients lacked the homozygous Gc 2 phenotype altogether. A chi 2 trend test showed that progression to AIDS had a strong positive association with the Gc 1f allele (p less than 0.0001) and a negative one with Gc 2 (p less than 0.05). It is proposed that Gc may be involved in viral entry into host cells, the ease of which varies with different allelic forms of Gc, according to their sialic acid content.

Rheumatic fever is associated with exaggerated activity of B cells with massive production of antibody to the Group A streptococcus. Gc (vitamin D-binding protein) is constitutively expressed on B-cell membranes in association with membrane immunoglobulin, and could be involved in cell activation. We therefore looked for associations between the three major Gc alleles and susceptibility to rheumatic fever in a homogeneous Arab population. Patients with tuberculosis or rheumatoid arthritis and control donors, were studied in parallel. Allele frequencies in the controls, rheumatoid and tuberculosis patients were identical to those found in a previous study of normal Arab donors. However, there was a striking association between Gc2 and rheumatic fever. This allele was twice as common in these patients as in controls (p = 0.0024), and was present in 56.4% of all rheumatic fever patients.