Immune mechanisms targeting malaria transmission: opportunities for vaccine development.

Introduction: Malaria continues to remain a major global health problem with nearly a quarter of a billion clinical cases and more than 600,000 deaths in 2022. There has been significant progress toward vaccine development, however, poor efficacy of approved vaccines requiring multiple immunizing doses emphasizes the need for continued efforts toward improved vaccines. Progress to date, nonetheless, has provided impetus for malaria elimination.

Dissemination and implementation research coordination and training to improve cardiovascular health in people living with HIV in sub-Saharan Africa: the research coordinating center of the HLB-SIMPLe Alliance.

As global adoption of antiretroviral therapy extends the lifespan of People Living with HIV (PLHIV) through viral suppression, the risk of comorbid conditions such as hypertension has risen, creating a need for effective, scalable interventions to manage comorbidities in PLHIV. The Heart, Lung, and Blood Co-morbiditieS Implementation Models in People Living with HIV (HLB-SIMPLe) Alliance has been funded by the National Heart, Lung, and Blood Institute (NHLBI) and the Fogarty International Center (FIC) since September 2020. The Alliance was created to conduct late-stage implementation research to contextualize, implement, and evaluate evidence-based strategies to integrate the diagnosis, treatment, and control of cardiovascular diseases, particularly hypertension, in PLHIV in low- and middle-income countries (LMICs).

Transmission-reducing and -enhancing monoclonal antibodies against gamete surface protein Pvs48/45.

Gamete surface protein P48/45 has been shown to be important for male gamete fertility and a strong candidate for the development of a malaria transmission-blocking vaccine (TBV). However, TBV development for homolog Pvs48/45 has been slow because of a number of challenges: availability of conformationally suitable recombinant protein; the lack of an challenge model; and the inability to produce gametocytes in culture to test transmission-blocking activity of antibodies. To support ongoing efforts to develop Pvs48/45 as a potential vaccine candidate, we initiated efforts to develop much needed reagents to move the field forward.

Assets for integrating task-sharing strategies for hypertension within HIV clinics: Stakeholder's perspectives using the PEN-3 cultural model.

Background: Access to antiretroviral therapy has increased life expectancy and survival among people living with HIV (PLWH) in African countries like Nigeria. Unfortunately, non-communicable diseases such as cardiovascular diseases are on the rise as important drivers of morbidity and mortality rates among this group. The aim of this study was to explore the perspectives of key stakeholders in Nigeria on the integration of evidence-based task-sharing strategies for hypertension care (TASSH) within existing HIV clinics in Nigeria.

Research opportunities for the primordial prevention of rheumatic fever and rheumatic heart disease-streptococcal vaccine development: a national heart, lung and blood institute workshop report.

also known as group A streptococcus (StrepA), is a bacterium that causes a range of human diseases, including pharyngitis, impetigo, invasive infections, and post-infection immune sequelae such as rheumatic fever and rheumatic heart disease. StrepA infections cause some of the highest burden of disease and death in mostly young populations in low-resource settings. Despite decades of effort, there is still no licensed StrepA vaccine, which if developed, could be a cost-effective way to reduce the incidence of disease.

Tertiary prevention and treatment of rheumatic heart disease: a National Heart, Lung, and Blood Institute working group summary.

Although entirely preventable, rheumatic heart disease (RHD), a disease of poverty and social disadvantage resulting in high morbidity and mortality, remains an ever-present burden in low-income and middle-income countries (LMICs) and rural, remote, marginalised and disenfranchised populations within high-income countries. In late 2021, the National Heart, Lung, and Blood Institute convened a workshop to explore the current state of science, to identify basic science and clinical research priorities to support RHD eradication efforts worldwide. This was done through the inclusion of multidisciplinary global experts, including cardiovascular and non-cardiovascular specialists as well as health policy and health economics experts, many of whom also represented or closely worked with patient-family organisations and local governments.

Building Capacity of Community Nurses to Strengthen the Management of Uncomplicated Hypertension in Persons Living with HIV in Low- and Middle-Income Countries.

Objectives: Poor training of non-physician healthcare workers (especially community nurses) could hinder the successful integration of cardiovascular disease (CVD) management into HIV chronic care in primary healthcare facilities in low- and middle-income countries. To address this limitation, we included a holistic training programme with a robust module for both practice facilitators and community nurses as part of the formative stages of the managing hypertension among people living with HIV: an integrated model (MAP-IT), which is a study that is evaluating the effectiveness of practice facilitation on the integration of a task-strengthening strategy for hypertension control (TASSH) into primary healthcare centres in Akwa Ibom State of Nigeria.

Methods: Between June and November 2021, 3 didactic training workshops were conducted using a training module which is based on the simplified Nigerian Hypertension Protocol for primary care and the World Health Organization (WHO) heart package.

Organizational readiness to implement task-strengthening strategy for hypertension management among people living with HIV in Nigeria.

Background: Hypertension (HTN) is highly prevalent among people living with HIV (PLHIV), but there is limited access to standardized HTN management strategies in public primary healthcare facilities in Nigeria. The shortage of trained healthcare providers in Nigeria is an important contributor to the increased unmet need for HTN management among PLHIV. Evidence-based TAsk-Strengthening Strategies for HTN control (TASSH) have shown promise to address this gap in other resource-constrained settings.

HIV-Related Stigma Research as a Priority at the National Institutes of Health.

The National Institutes of Health (NIH) recognizes that, despite HIV scientific advances, stigma and discrimination continue to be critical barriers to the uptake of evidence-based HIV interventions. Achieving the Ending the HIV Epidemic: A Plan for America (EHE) goals will require eliminating HIV-related stigma. NIH has a significant history of supporting HIV stigma research across its Institutes, Centers, and Offices (ICOs) as a research priority.

Functional Conservation of P48/45 Proteins in the Transmission Stages of (Human Malaria Parasite) and . (Murine Malaria Parasite).

Sexual-stage proteins have a distinct function in the mosquito vector during transmission and also represent targets for the development of malaria transmission-blocking vaccine. P48/45, a leading vaccine candidate, is critical for male gamete fertility and shows >50% similarity across various species of We evaluated functional conservation of P48/45 in and with the motivation to establish transgenic strains expressing P48/45 (Pvs48/45) in an assay to evaluate the transmission-blocking activity of antibodies elicited by Pvs48/45. Homologous recombination was employed to target / (/) for knockout (KO) or for its replacement by two different forms of / (/) (the full-length gene and a chimeric gene consisting of / 5' signal and 3' anchor sequences flanking /).

Comparative functional potency of DNA vaccines encoding Plasmodium falciparum transmission blocking target antigens Pfs48/45 and Pfs25 administered alone or in combination by in vivo electroporation in rhesus macaques.

Antibodies recognizing conformational epitopes in Pfs48/45, an antigen expressed on the surface of Plasmodium falciparum gametes and zygotes, have firmly established Pfs48/45 as a promising transmission blocking vaccine (TBV) candidate. However, it has been difficult to reproducibly express Pfs48/45 in a variety of recombinant expression systems. The goal of our studies was to evaluate functional immunogenicity of Pfs48/45 using DNA vaccine format in rhesus macaques.

Enhanced Adhesion of Mosquitoes to Rough Surfaces.

Insects and small animals capable of adhering reversibly to a variety of surfaces employ the unique design of the distal part of their legs. In the case of mosquitoes, their feet are composed of thousands of micro- and nanoscale protruding structures, which impart superhydrophobic properties. Previous research has shown that the superhydrophobic nature of the feet allows mosquitoes to land on water, which is necessary for their reproduction cycle.

Impact of the Charge Ratio on the In Vivo Immunogenicity of Lipoplexes.

Purpose: The present study investigated the immunogenic potential of different cationic liposome formulations with a DNA plasmid encoding Pfs25, a malaria transmission-blocking vaccine candidate.

Methods: Pfs25 plasmid DNA was complexed with cationic liposomes to produce lipoplexes at different charge ratios of the cationic lipid head group to the nucleotide phosphate (N:P). The formation of lipoplexes was visualized by Cryogenic-TEM.

Antibodies elicited during natural infection in a predominantly Plasmodium falciparum transmission area cross-react with sexual stage-specific antigen in P. vivax.

Infections caused by Plasmodium falciparum and P. vivax account for more than 90% of global malaria burden. Exposure to malaria parasite elicits immune responses during natural infection and it is generally believed that the immunity is not only stage specific but also species specific.

Immunogenicity and malaria transmission reducing potency of Pfs48/45 and Pfs25 encoded by DNA vaccines administered by intramuscular electroporation.

Pfs48/45 and Pfs25 are leading candidates for the development of Plasmodium falciparum transmission blocking vaccines (TBV). Expression of Pfs48/45 in the erythrocytic sexual stages and presentation to the immune system during infection in the human host also makes it ideal for natural boosting. However, it has been challenging to produce a fully folded, functionally active Pfs48/45, using various protein expression platforms.

Reduced immunogenicity of Plasmodium falciparum gamete surface antigen (Pfs48/45) in mice after disruption of disulphide bonds - evaluating effect of interferon-γ-inducible lysosomal thiol reductase.

Sexual stages of Plasmodium are critical for malaria transmission and stage-specific antigens are important targets for development of malaria transmission-blocking vaccines. Plasmodium falciparum gamete surface antigen (Pfs48/45) is important for male gamete fertility and is being pursued as a candidate vaccine antigen. Vaccine-induced transmission-blocking antibodies recognize reduction-sensitive conformational epitopes in Pfs48/45.

Insight into phagocytosis of mature sexual (gametocyte) stages of Plasmodium falciparum using a human monocyte cell line.

During natural infection malaria parasites are injected into the bloodstream of a human host by the bite of an infected female Anopheles mosquito. Both asexual and mature sexual stages of Plasmodium circulate in the blood. Asexual forms are responsible for clinical malaria while sexual stages are responsible for continued transmission via the mosquitoes.

Nanovaccines for malaria using Plasmodium falciparum antigen Pfs25 attached gold nanoparticles.

Malaria transmission-blocking vaccines (TBV) targeting sexual stages of the parasite represent an ideal intervention to reduce the burden of the disease and eventual elimination at the population level in endemic regions. Immune responses against sexual stage antigens impair the development of parasite inside the mosquitoes. Target antigens identified in Plasmodium falciparum include surface proteins Pfs230 and Pfs48/45 in male and female gametocytes and Pfs25 expressed in zygotes and ookinetes.

Evaluation of the Impact of Codon Optimization and N-Linked Glycosylation on Functional Immunogenicity of Pfs25 DNA Vaccines Delivered by In Vivo Electroporation in Preclinical Studies in Mice.

Plasmodium falciparum sexual stage surface antigen Pfs25 is a well-established candidate for malaria transmission-blocking vaccine development. Immunization with DNA vaccines encoding Pfs25 has been shown to elicit potent antibody responses in mice and nonhuman primates. Studies aimed at further optimization have revealed improved immunogenicity through the application of in vivo electroporation and by using a heterologous prime-boost approach.