Characterizing Humoral Immune Response to Mosquito Bites

Summary

The characteristics of the humoral response directed against mosquito saliva antigens are not known precisely. This is a major limitation for using immunological markers as an outcome in epidemiological trials and as an indicator for operational deployment of interventions. Recent advances in the assembly of the genome of some Anopheles and Aedes mosquito vector species has facilitated the identification of new candidate peptides in silico, using the sequences of orthologous salivary gland proteins and B-cell prediction algorithms. The objective of this study is to assess the humoral immune response directed against candidate peptides following controlled exposure to laboratory-adapted colonies of An. minimus, An. maculatus and An. dirus, Ae. aegypti and Ae. albopictus.

This research will provide essential information to identify and validate immunological markers of human exposure to malaria and dengue mosquito vectors in Southeast Asia. Immunological markers would be useful to understand transmission dynamics and predict the risk of transmission as part of a surveillance system, and to assess the efficacy of vector-control interventions in entomological trials or during operational deployment of interventions in the region.

Conditions

• Malaria
• Dengue

Interventions

BIOLOGICAL

Mosquito bites

Participants will be exposed to mosquito bites. For the low-dose challenge, five 5 to 7-day-old nulliparous female imagoes (i.e. that have never blood fed before) will be introduced individual into 50 mL plastic tube covered with netting material. For high-dose challenge, 47 mosquitoes will be split into four plastic cups of 10 cm in diameter covered with netting material (three cups with 12 mosquitoes and one cup with 11 mosquitoes), and 3 mosquitoes will be introduced individually into 50 mL plastic tubes. Mosquito bites administered on participant's arm will be used to assess immediate and delayed skin reactions. Immediate and delayed skin reactions will be recorded respectively 20-30 min and 24-36 hours after the day 14 and day 21 challenges, requiring additional visits at day 15 and 22.

Sponsors & Collaborators

• National Health and Medical Research Council, Australia

  collaborator OTHER

• Burnet Institute

  collaborator OTHER

• Agency for Science, Technology and Research

  collaborator OTHER

• University of Oxford

  lead OTHER

Principal Investigators

• François Nosten · Shoklo Malaria Research Unit

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2021-01-21

Primary Completion

2025-07-23

Completion

2025-07-23

Countries

• Thailand

Study Locations