An HIV drug that suppresses the activity of the CCR5 receptor—a collection of proteins on the surface of certain immune cells—was associated with better renal function in kidney transplant recipients with HIV compared to people who took a placebo in a randomized trial. Study participants taking the drug, called maraviroc, also experienced lower rates of transplant rejection than those taking placebo, but the difference was not statistically significant due to lower-than-expected rejection rates across the entire study population. The findings of the NIAID-sponsored trial were presented today at the 2024 American Transplant Congress in Philadelphia. 

The CCR5 receptor helps HIV enter CD4+ T cells. Some people have a genetic mutation that prevents the CCR5 receptor from working, and either cannot acquire HIV or experience slower HIV-related disease progression if living with the virus. It has separately been observed that people with the same CCR5 genetic mutation have better outcomes following kidney and liver transplantation. The CCR5 antagonist class of antiretroviral drugs was developed to mimic the naturally occurring CCR5 mutation and is a well tolerated component of HIV treatment, but the drugs have not been evaluated as an intervention to improve transplantation outcomes in people. Furthermore, transplant recipients with HIV more frequently experience transplant rejection and elevated CCR5 activity than transplant recipients without HIV.

A research team led by the University of California San Francisco conducted a U.S.-based Phase 2 trial to assess the safety and tolerability of the CCR5 antagonist maraviroc given daily from the time of transplant onward among kidney transplant recipients, and to compare renal function of people taking daily maraviroc to those taking a placebo one year (52 weeks) post-transplant. All study participants were living with HIV and were virally suppressed on antiretroviral therapy (ART) regimens. The study randomized 97 participants to receive maraviroc or a placebo in addition to their continued ART regimens post-transplant. Of them, only 27 participants were able to complete all necessary study examinations through 52 weeks due to logistical complications from the SARS-CoV-2 pandemic. At one-year post-transplant, the mean estimated glomerular filtration rate—a measure of how well kidneys were working—was significantly higher in participants receiving maraviroc in addition to their ART regimen compared with participants receiving ART and placebo (59.2 versus 49.3 mL/min/1.73m²). The drug was safe and well tolerated. 

Four of the 49 participants taking maraviroc and 6 of the 48 participants taking placebo experienced transplant rejection, but this difference was not statistically significant given the relatively small sample size. Transplant rejection rates were lower than expected across both study groups, which the study team suggests may be a favorable outcome of the ART regimens most participants were taking. 

The addition of maraviroc significantly improved renal function in kidney transplant recipients with HIV compared to placebo. According to the authors, these findings warrant further exploration of the benefit of CCR5 antagonists in all kidney transplant recipients regardless of HIV status.

For more information about this study, please visit ClinicalTrials.gov and use the identifier NCT02741323.

Reference:

Brown et al. Beneficial Impact of CCR5 Blockade in Kidney Transplant Recipients with HIV. American Transplant Congress in Philadelphia, Pennsylvania. Tuesday, June 4, 2024.

NIAID scientists and colleagues are investigating a potential treatment strategy against Lyme disease that would directly suppress Borrelia burgdorferi, the bacterium that causes the disease. If successful, their idea could reduce or end aggressive broad-spectrum antibiotic treatments that can be drawn-out and destroy the body’s helpful bacteria. The study appears in Frontiers in Antibiotics from scientists at NIAID’s Rocky Mountain Laboratories and colleagues at Purdue University.

The strategy involves the oligopeptide (Opp) transport system that most bacteria use as a secondary nutrition route to move small protein-like peptides through the bacteria. But B. burgdorferi, the researchers learned in a 2017 study, depends on the Opp system for survival, growth, and replication. They subsequently hypothesized that if they could impede the Opp system, maybe the bacterium would stop growing and die.

To test their theory they developed a method to screen 2,240 chemical compounds from a commercial library used for small-molecule drug discovery. They wanted to know if any compounds would bind to a prominent transport system protein known as OppA2. The research team identified eight compounds that did so, and of those, two compounds – C2 and C7 – significantly slowed B. burgdorferi growth, making the Opp system a viable, previously unexplored treatment target.

Next the scientists plan to screen more compounds, hoping to optimize binding to different OppA proteins (there are five to investigate) while still hindering B. burgdorferi growth.

“By targeting a system that appears to be only essential to Borrelia, it is possible that we could vastly improve current treatments by replacing them with a highly specific treatment that could reduce post-treatment complications,” study senior author Ashley Groshong, Ph.D., said.

Reference:

K Holly and A Kataria, et al. Unguarded Liabilities: Borrelia burgdorferi’s complex amino acid dependence exposes unique avenues of inhibition. Frontiers in Antibiotics DOI: 10.3389/frabi.2024.1395425 (2024).

Nearly 25 million people in the United States have asthma, including 4.7 million children and adolescents. Almost 10 percent of these individuals had one or more asthma attacks within the past 12 months. Asthma can cause coughing, wheezing, chest tightness, and shortness of breath. In severe cases, breathing becomes extremely difficult. Worsening asthma can lead to missed time at school and work, emergency room visits, and even death.

Today on World Asthma Day, NIAID reaffirms its commitment to reducing illness from this chronic lung syndrome and improving quality of life for people with asthma through research that informs the development of new asthma prevention and treatment strategies. NIAID-funded studies in children and adolescents recently uncovered new risk factors for asthma and a previously unreported cause of frequent, severe asthma attacks. In addition, two new NIAID-supported studies aim to further asthma therapeutics development by shedding light on the behavior of airway-cell genes and proteins involved in regulating asthma severity and by defining poorly understood causes of airway inflammation in underserved youth with the disorder. Learn more about these recent research highlights below.

Asthma Risk Factors 

Nearly a third of infants who are hospitalized with a severe form of a common childhood lung infection called bronchiolitis develop asthma later in childhood. Predicting which infants with severe bronchiolitis are at highest risk for asthma, understanding why, and developing effective interventions remain challenges. Investigators from the NIAID-supported 35th Multicenter Airway Research Collaboration (MARC-35) recently identified genetic factors that may underlie the bronchiolitis–asthma link.

• Environmental exposures such as tobacco smoke are known to modify the function of certain genes in people, potentially resulting in long-term health effects. In one study, MARC-35 researchers examined such modifications by analyzing DNA in nasal swabs from 625 infants hospitalized with bronchiolitis. The scientists found that the genomes of some infants with severe bronchiolitis had modifications potentially caused by environmental exposures in the uterus or after birth, and these changes were associated with increased risk for asthma later in childhood. Now investigators want to identify which exposures had this detrimental effect.
• In a second study, MARC-35 researchers focused on small molecules called microRNAs, which derive from DNA and help control the genetic information that directs the building of proteins. The scientists analyzed microRNAs in nasal-swab DNA from 575 children who were hospitalized with bronchiolitis in infancy and followed until 6 years of age. The investigators identified 23 microRNAs that were turned on or off to different extents in the children who developed asthma by age 6 compared to those who did not. Now scientists want to identify what is triggering these differences and how to block them to reduce asthma risk.

Other investigators from the NIAID-funded Urban Environment and Childhood Asthma (URECA) study linked the composition of all the microbes found in the nose—the nasal microbiota—at age 3 years to respiratory health profiles ranging from high to low risk for developing asthma by age 7 years. The scientists also found that both exposure to certain microbes in house dust during infancy and a genetic predisposition to developing allergic diseases later in childhood influence how the airway microbiota develops. 

Therapeutic Insights

Scientists in NIAID’s Laboratory of Allergic Diseases recently demonstrated that a protein called RSG4 in smooth muscle cells of airway walls affects asthma severity in part by regulating airway inflammation independent of so-called G proteins. This finding builds on the lab’s 2020 discovery that blocking RSG4 in a mouse model of asthma reduced a key feature of the disease called airway hyper-responsiveness. This is a heightened sensitivity to molecules that activate smooth muscle cells in airway walls, leading to excessive airway constriction. Together the findings suggest that RSG4 in these cells could be a therapeutic target for asthma.

NIAID-supported researchers discovered recently that structural changes to nerve-cell networks in upper-airway tissues underlie asthma attacks in children who are hospitalized due to these attacks more than once a year. This contrasts with asthma attacks in children who are hospitalized less frequently, as those attacks are characterized by immune-system activity like allergic inflammation and responses to infections. The new findings, reported by the Ohio site in the NIAID-funded Childhood Asthma in Urban Settings (CAUSE) network, suggest that preventing and treating frequent severe asthma attacks in children may require an untraditional approach that targets the nervous system.

The CAUSE network also launched a new study in April 2024 to improve understanding of how airway inflammation influences asthma severity at a cellular and molecular level in children and adolescents who live in low-income urban communities. Airway inflammation in asthma may be categorized as related to a “type 2” immune response, which also plays a role in allergic diseases, or a non-type 2 immune response. The new study aims to define the cellular and molecular mechanisms associated with each type of airway inflammation in severe asthma to identify potential targets for new therapies.

NIAID thanks the hundreds of study participants and their caregivers who made these research advances possible and who help scientists continue to illuminate the complex and varied nature of asthma to reduce the burden of this disease.

by Jeanne Marrazzo, M.D., M.P.H., NIAID Director

The HIV research community is led by scientists with deep personal commitments to improving the lives of people with and affected by HIV. Some researchers, like me, have pursued this cause since the start of the HIV pandemic, growing our careers studying HIV from basic to implementation science. Our collective decades of work have generated HIV testing, prevention and treatment options beyond what we could have imagined in the 1980s. Those advances enable NIAID to explore new frontiers: expanding HIV prevention and treatment modalities, increasing understanding of the interplay between HIV and other infectious and non-communicable diseases, optimizing choice and convenience, and building on the ever-growing knowledge base that we need to develop a preventive vaccine and cure. The next generation of leaders will bring these concepts to fruition, and we need to welcome and support them into the complex and competitive field of HIV science.

Click below for a video in which NIAID grantees and I discuss the value and experience of early-stage HIV investigators (the audio described version is here):

NIAID wants to fund more new HIV scientists and we have special programs and funding approaches to meet that goal. This week, the NIH Office of AIDS Research will host a virtual workshop on early-career HIV investigators tomorrow, April 24, and NIAID will host its next grant writing Webinars in May, June, and July.

For more information about programs and support for new and early-stage investigators as well as people starting to implement their first independent grant, visit these NIAID and NIH resources: 

Information for New Investigators (NIAID)

HIV/AIDS Information for Researchers (NIAID)

OAR Early Career Investigator Resources (NIH)

Resources of Interest to Early-Stage Investigators (NIH)

Early Career Reviewer Program (NIH)

Sexually transmitted infections (STIs) are caused by bacteria, viruses, or parasites. STIs have a devastating impact on adults and infants and annually affect millions of people in the United States. Certain STIs can increase a person’s risk of developing cancer and increase the likelihood of acquiring or transmitting HIV. In addition, STIs can cause long-term health complications, especially in the reproductive and central nervous systems. In rare cases, they can lead to serious illness or death. 

NIAID supports research across the spectrum from basic to clinical science to develop effective diagnostic, preventive and therapeutic approaches to STIs in alignment with the National STI Strategic Plan. In recognition of National STI Awareness Week, NIAID shares a snapshot of new projects and recent scientific advances in STI research. 

Improving treatment for syphilis and trichomoniasis

New reports of syphilis and congenital syphilis are increasing at an alarming rate in the United States. Syphilis is caused by the bacterium Treponema pallidum. Benzathine penicillin G (BPG) is one of only a few antibiotics known to effectively treat syphilis. There is currently a shortage of BPG, and some people are allergic to penicillin antibiotics. In February 2024, NIAID convened a workshop with a wide range of experts on alternative therapies to BPG for the treatment of adult syphilis, neurosyphilis, and syphilis in pregnant persons and infants. The workshop addressed preclinical evaluation of candidate drugs, the potential need for studies on how candidate drugs are processed in the body during pregnancy, and how to approach clinical trials of treatment for congenital syphilis. This work is part of NIAID’s comprehensive portfolio of syphilis diagnosis, prevention, and treatment research. 

Trichomoniasis is the most common parasitic STI, caused by Trichomonas vaginalis. Trichomoniasis can increase the risk of getting or spreading other STIs, including HIV. The parasite can also cause inflammation of the cervix and the urethra. T. vaginalis is treated with an antibiotic drug class called nitroimidazoles. The currently recommended nitroimidazole, called metronidazole, cures 84-98% of T. vaginalis cases but does have high rates of breakthrough infection. A new project led by Tulane University will examine a single dose of secnidazole, a medicine in the same drug class, as a more effective and cost-effective treatment option for women and men. 

Developing a vaccine for herpes simplex virus 2

Herpes simplex virus 2 (HSV-2) is a common subtype of herpes simplex virus that is transmitted through sexual contact. The Centers for Disease Control and Prevention estimates that 18.6 million people aged 15 years and older United States live with HSV-2. In severe cases, HSV-2 may lead to life-threatening or long-term complications. There is no licensed preventive HSV-2 vaccine, and there is no cure. A new project led by the University of Pennsylvania seeks to define correlates of protection for HSV-2, meaning they intend to identify immune processes involved in preventing HSV-2 disease. They will do this by analyzing laboratory samples from animal studies of a promising preventive vaccine candidate that they developed with prior funding. That vaccine candidate is also now in an industry-sponsored early-stage clinical trial. The same project will expand on the HSV-2 targets in the preventive vaccine to develop a therapeutic vaccine concept to reduce recurrent outbreaks. This research responds to the scientific priorities in the NIH Strategic Plan for Herpes Simplex Virus Research.

Increasing fundamental knowledge of bacterial vaginosis 

Bacterial vaginosis (BV) results from an imbalance in the vaginal microbiome. BV can be caused by sexual activity, douches and menstrual products. BV can increase women’s biological susceptibility to HIV and other STIs and can cause premature birth or low birthweight if untreated in pregnant people. In a recent publication, NIAID-supported researchers, led by researchers at the University of Washington and University of California San Diego, shared findings on how damage to the vaginal skin barrier occurs during bacterial vaginosis. Those skin barrier cells, called epithelial cells, are covered in carbohydrate molecules called glycans. The research team found that people with BV had damaged glycans on their vaginal epithelial cells. They suggested that future work should examine the relationship between treatment and restoration of normal glycans. If an association is detected, it could help healthcare providers monitor for successful treatment outcomes to reduce the likelihood that BV will return after a course of treatment. The findings were published in Science Translational Medicine. 

These activities are among the research investments in NIAID’s STI portfolio. For more information on STIs, please visit:

• NIAID Diseases & Conditions: Sexually Transmitted Infections
• U.S. Department of Health and Human Services STI National Strategic Plan

The National Institutes of Health recently issued $26M in awards to HIV research institutions in its fifth year supporting implementation science under the Ending the HIV Epidemic in the U.S. (EHE) initiative. These awards are the latest investments in a program that is rapidly and rigorously generating evidence to inform the unified domestic HIV response by agencies in the Department of Health and Human Services. 

The EHE initiative aims to achieve a 90% reduction in the number of new HIV infections in the United States by 2030. Since the initiative was announced in 2019, NIH has contributed by supporting implementation science projects through its network of Centers for AIDS Research (CFAR) and the National Institute of Mental Health (NIMH) AIDS Research Centers (ARC). CFARs are co-funded by 11 NIH institutes and centers (ICs), including the National Institute of Allergy and Infectious Diseases (NIAID). NIH ICs provide scientific stewardship to participating institutions in collaboration with the Fogarty International Center and the NIH Office of AIDS Research, which coordinates the NIH HIV research program across the agency. CFAR and ARC-affiliated investigators conduct research in jurisdictions that are disproportionately affected by HIV, and many of the CFAR and ARC member institutions are based in these communities. 

VIDEO: Jeanne Marrazzo, M.D., M.P.H., NIAID Director, discusses NIH’s role in the EHE (audio description version here):

NIH EHE projects enable academic institutions to partner with state and local leaders to jointly translate implementation research findings into improved delivery of HIV testing, prevention, treatment, and response services for priority populations and in priority geographic areas. Projects funded this year are designed to increase and share available knowledge on locally appropriate strategies to: 

• detect and respond to HIV “clusters,” i.e., groups of people and communities experiencing rapid HIV transmission;
• leverage pharmacies as HIV service locations; 
• ensure uninterrupted HIV care for people returning to their communities following incarceration; and
• develop approaches that address intersecting diseases and conditions that exacerbate health inequities and impact HIV outcomes, including such as viral hepatitis, sexually transmitted infections, and substance use and mental health disorders.

Since Fiscal Year 2019, NIH has funded 253 projects across 50 geographic areas prioritized by EHE. The latest EHE awards to CFARs and ARCs support 47 projects, 8 implementation science hubs, and 1 coordinating center. Hubs provide technical support, coaching, training, and consultative services to funded EHE research teams. The coordinating center provides infrastructure for collaboration and sharing best practices in HIV implementation science. In addition to the CFAR/ARC supplements, NIH supported multiple larger research projects in 2023, including 3 R01 awards, 2 R34 awards, and 1 coordinating center. In September 2023, NIH released a Notice of Special Interest to solicit project proposals from independent investigators for Fiscal Year 2024.

EHE Project Spotlights

The knowledge generated by NIH EHE projects is reviewed with HHS EHE partners to accelerate learning and program improvement. Two projects below illustrate how EHE implementation science projects have already enhanced locally tailored HIV service delivery:

Miami, Florida

Miami-Dade County, Florida has one of the highest rates of HIV incidence in the United States, and yet use of pre-exposure prophylaxis (PrEP) to prevent HIV acquisition remains relatively low. Researchers at the University of Miami, in collaboration with the Florida Department of Health (DOH) and a local community-based organization called Prevention305, developed a process to apply real-time DOH epidemiologic data to prioritize new geographic locations for placement of their mobile PrEP clinics. In collaboration with community partners, the project developed a new outreach approach: “Test-to-PrEP,” in which people using PrEP are engaged to distribute free HIV self-tests and PrEP referrals through their social networks. They have worked with 100 current PrEP clients to engage members of their social network with information about PrEP provide them with HIV self-tests. More than one third of the 117 HIV self-test kit recipients who confirmed they used the test reported they had not previously known about PrEP. Self-reported knowledge and likelihood to use PrEP increased significantly after kit receipt. PrEP clients also reported feeling comfortable with the distribution and enthusiastic about the strategy. Their work has provided a blueprint for mobile HIV prevention and related services as a strategy to interrupt further transmission.

Mobile clinic service team in the Liberty City neighborhood of Miami, Florida

Credit: University of Miami

Shelby County, Tennessee

Rural areas like Shelby County pose distinct challenges to HIV service delivery, including a lack of outpatient providers and fragmented health care and social services, as well as stigma and medical mistrust. To overcome these barriers, researchers from University of Massachusetts, Lowell, in collaboration with the University of Memphis and the Shelby County Health Department, used an implementation research approach to adapt and provide an evidence-based training and capacity-building program in HIV care for existing community health workers (CHWs), with input from HIV care providers, people with HIV, and CHWs. CHWs are frontline public health workers who are also members of the community they serve. The team has trained 67 CHW to support HIV care across eight agencies and has provided coaching sessions to supervisors around how to sustain this workforce. They are assessing the sustainability and effectiveness of this program in addressing service gaps and improving health outcomes through follow-up surveys with health care agency staff and county health leaders. 

Community health worker Michelle Anderson discussing culturally relevant care HIV care with colleagues in Memphis, Tennessee.

Credit: University of Massachusetts, Lowell

In addition to NIH, HHS agencies and offices participating in EHE include the Centers for Disease Control and Prevention; the Health Resources and Services Administration; the Indian Health Service; the Office of the Assistant Secretary for Health; and the Substance Abuse and Mental Health Services Administration. 

To view a complete list of NIH research projects supported with EHE initiative funding, please visit the awards page. 

To learn more about EHE, please visit HIV.gov.

Reference: 

Butts, SA et al. Addressing disparities in Pre-exposure Prophylaxis (PrEP) access: implementing a community-centered mobile PrEP program in South Florida. BMC Health Services Research. DOI 10.1186/s12913-023-10277-1 (2023).

Johnson, AL et al. “Test-To-PrEP”: Assessing Reach and Adoption of a New Approach to Increase HIV Testing and PrEP Knowledge Using HIV Self-Test Kit Distribution Through PrEP Clients' Social Networks. Journal of Acquired Immune Deficiency Syndromes. DOI 10.1097/QAI.0000000000003294 (2023). 

Rajabiun, S et al. Using Implementation Science to Promote Integration and Sustainability of Community Health Workers in the HIV Workforce. Journal of Acquired Immune Deficiency Syndromes. DOI 10.1097/QAI.0000000000002966 (2023).