Immune Response Study for Tick Bites

Overseen By Siu-Ping Ng, R.N.

Age: 18+

Sex: Any

Trial Phase: Phase 1 & 2

Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)

Must not be taking: Anticoagulants, Oral steroids

Disqualifiers: Keloids, Bleeding disorders, Allergies, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 6

60 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand the skin's response to tick bites, potentially aiding in the development of future vaccines against tick-borne diseases like Lyme disease. Researchers will place lab-bred ticks (Ixodes Scapularis Tick, also known as Deer Tick or Blacklegged Tick) on participants' skin to monitor reactions over several months. Healthy adults with no history of tick bites or tick-borne diseases are ideal candidates for this study. The process involves skin biopsies and blood samples, with follow-up visits to track any changes or symptoms. As a Phase 1 trial, the research focuses on understanding how the treatment works in people, offering participants the chance to contribute to groundbreaking research.

Do I have to stop taking my current medications for the trial?

The trial does not specify if you need to stop taking your current medications, but you cannot have taken anticoagulants in the past 28 days or oral or IV steroids in the 2 weeks before each tick placement. Other forms of steroids like topical or inhaled are allowed.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

In this study, researchers examine how the skin reacts to tick bites. Limited information exists on the safety of this specific procedure, as the study is in its early stages. Researchers closely monitor for safety and any side effects.

The study uses clean ticks bred in a lab, reducing the risk of disease. Participants undergo a skin punch biopsy, where a small piece of skin is removed, and ticks are placed on their skin. The ticks are removed after a short time. These procedures are common in research and are usually well-tolerated. Some participants might experience mild skin irritation or itching from the tick bites.

Overall, the study prioritizes safety. Researchers regularly check participants to assess their well-being.

Why are researchers excited about this trial?

Most treatments for tick bites focus on managing symptoms or preventing infections, like using antibiotics for Lyme disease. But the immune response study for Ixodes scapularis tick bites is exploring something different. Unlike standard treatments, this study is investigating how the human immune system reacts to tick bites themselves, which could lead to innovative ways to prevent tick-borne diseases before they even start. Researchers are excited because understanding this immune response could open new avenues for vaccines or therapies that stop infections at the source, rather than just treating them after they occur.

What evidence suggests that this trial's procedures could be effective for understanding immune responses to tick bites?

Research shows that understanding the immune system's response to tick bites is crucial for developing future vaccines against tick-borne diseases. Early studies found that tick bites activate certain cells in the skin and blood. This response might help prevent infections like Lyme disease from spreading. By examining how the skin and body react to tick bites, researchers aim to discover better ways to protect people from these illnesses. Although direct evidence of a vaccine does not yet exist, these findings could lead to new prevention methods.

Who Is on the Research Team?

Adriana R Marques, M.D.

Principal Investigator

National Institute of Allergy and Infectious Diseases (NIAID)

Are You a Good Fit for This Trial?

Healthy adults over 18, with blood group B or AB and normal IgE levels, who've never had a tick-borne disease or known tick bite. They must be willing to follow the study procedures for about 5-7 months and use effective contraception. Excluded are those with severe allergies, skin conditions, uncontrolled diabetes, cancer requiring immunosuppression (except non-melanoma skin cancers), HIV, chronic viral hepatitis, syphilis, history of severe allergic reactions to insect venom or drugs.

Inclusion Criteria

No known tick bite

I am a man who can father children and will use contraception.

My hemoglobin level is at least 13.0 g/dL if I am male, or 12 g/dL if I am female.

Exclusion Criteria

Refusal to allow storage of samples and data for future usage

Treatment with another investigational drug or other intervention within the past 30 days

I do not have severe skin conditions, uncontrolled diabetes, other cancers, autoimmune diseases needing strong immune system medications, or a history of HIV, chronic hepatitis, or syphilis.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Initial Tick Feeding Procedure

Participants undergo the first tick feeding procedure with 10 ticks placed at two sites, followed by skin biopsies and blood samples.

1 week

1 visit (in-person)

Second Tick Feeding Procedure

Participants repeat the tick feeding procedure with 10 ticks at one site, followed by skin biopsies and blood samples.

2-8 weeks after initial procedure

1 visit (in-person), 1 follow-up (telephone)

Third Tick Feeding Procedure

Participants undergo the third tick feeding procedure with 10 ticks at one site, followed by skin biopsies and blood samples.

2-8 weeks after second procedure

1 visit (in-person), 1 follow-up (telephone)

Follow-up

Participants are monitored for safety and effectiveness after the final tick removal, with blood samples and health discussions.

4-6 weeks and 3 months after final tick removal

2 visits (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Ixodes Scapularis Tick

Trial Overview The trial is studying how human skin responds to deer tick bites. Participants will undergo multiple sessions where lab-bred ticks are placed on their skin and later removed after a few days. Skin biopsies before and after tick placement as well as blood samples will be taken periodically throughout the study.

How Is the Trial Designed?

Group I: 1 Active Control 3 Interventions

Healthy Volunteer

Who Is Running the Clinical Trial?

National Institute of Allergy and Infectious Diseases (NIAID)

Lead Sponsor

Trials

3,361

Recruited

5,516,000+

Published Research Related to This Trial

The study successfully identified several antigens from the Ixodes scapularis tick that can induce a protective immune response, which is crucial for developing effective tick vaccines.

Using a cDNA expression library combined with immunization and sequence analysis proved to be an efficient method for discovering candidate antigens that can help combat tick infestations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Identification of protective antigens for the control of Ixodes scapularis infestations using cDNA expression library immunization. Almazán, C., Kocan, KM., Bergman, DK., et al.[2019]

This study is the first to analyze the immune response in humans to Ixodes scapularis tick bites using advanced RNA sequencing techniques, revealing key immune pathways like interleukin-17 signaling and platelet activation.

The findings suggest that the human response to tick bites shares similarities with that of guinea pigs that develop resistance to ticks, providing valuable insights for creating new biomarkers and potential anti-tick vaccines for humans.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Bulk and single-nucleus RNA sequencing highlight immune pathways induced in individuals during an Ixodes scapularis tick bite. Tang, X., Lynn, GE., Cui, Y., et al.[2023]

Repeated infestations with pathogen-free Ixodes scapularis nymphs did not lead to acquired resistance in C3H/HeN mice, indicating that the immune response may not strengthen with multiple exposures to ticks.

However, significant differences were observed in the lymphocyte responses to tick salivary gland proteins between infested and noninfested mice, suggesting that tick saliva can modulate immune responses even without pathogen exposure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of repeated infestations with pathogen-free Ixodes scapularis (Acari: Ixodidae) on in vitro lymphocyte proliferation responses of C3H/HeN mice. Schoeler, GB., Manweiler, SA., Bergman, DK., et al.[2019]

The review analyzes the immune-related genes in the genome of Ixodes scapularis (deer tick) to understand how these genes influence the tick's ability to persistently harbor pathogens like Borrelia burgdorferi, the cause of Lyme disease.

Understanding the immune responses of deer ticks is crucial for developing new strategies to combat tick-borne diseases, as it may reveal how these ticks manage to maintain infections without being affected by their own immune system.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Immunity-related genes in Ixodes scapularis--perspectives from genome information. Smith, AA., Pal, U.[2023]

Infestation of C3H/HeJ mice with infected Ixodes scapularis ticks led to an early increase in IL-4 levels and a decrease in TH1 cytokines like IL-2 and IFN-gamma, indicating a shift towards a TH2 immune response that may influence Lyme disease susceptibility.

In contrast, BALB/c mice showed only temporary changes in cytokine levels after tick exposure, suggesting that the immune response to infected ticks varies significantly between mouse strains, which could affect the transmission dynamics of Borrelia burgdorferi.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Ixodes scapularis and Borrelia burgdorferi on modulation of the host immune response: induction of a TH2 cytokine response in Lyme disease-susceptible (C3H/HeJ) mice but not in disease-resistant (BALB/c) mice. Zeidner, N., Mbow, ML., Dolan, M., et al.[2022]

Citations