Joel Vega-Rodriguez, Ph.D.

The Molecular Parasitology and Entomology Unit (MPEU) investigates the intricate interactions between Plasmodium parasites, their mosquito vectors, and the human host to uncover critical mechanisms driving malaria and vector-borne pathogen transmission. The malaria parasite encounters severe developmental bottlenecks during its life cycle, particularly within the mosquito and at the point of transmission to a new host. These stages present prime targets for novel malaria interventions. Our research focuses on identifying and characterizing molecular interactions that support parasite survival and infectivity, with the ultimate goal of developing innovative strategies to block malaria transmission.

Our lab explores how Plasmodium parasites hijack molecules from both human plasma and mosquito hemolymph to facilitate transmission and immune evasion. One major research focus examines the role of the human blood factors in enabling parasite survival and development within both the mosquito and vertebrate host. Another key area of investigation is how the mosquito saliva regulates the biology of the blood ingested by the mosquito and how it facilitates Plasmodium parasite transmission to both, humans and mosquitoes. A third research focus is investigating how sporozoites influence the mosquito salivary glands and saliva, and how these changes impact parasite transmission. Our work may provide new targets for interventions to curtail the transmission of malaria parasites, knowledge that can be applied to also prevent transmission of other vector-borne pathogens. Using a combination of cutting-edge techniques—including single-cell transcriptomics, proteomics, parasite and mosquito transgenesis, and in vivo imaging—we aim to uncover new molecular targets that could be leveraged for malaria prevention, such as genetically engineered mosquitoes, targeted drug therapies, and novel vaccine candidates.

By integrating molecular parasitology, entomology, and host-pathogen interaction studies, MPEU is committed to advancing our understanding of malaria and other vector-borne diseases transmission biology and translating these insights into tangible solutions for control and eradication.

Figure 1: As a mosquito feeds on blood, it ingests its own saliva, which contains bioactive proteins that prevent clotting and reduce inflammation in the ingested blood. Meanwhile, the malaria parasite manipulates both mosquito saliva and human blood proteins to enhance its transmission. In the mosquito midgut, the parasite also hijacks blood proteins to counteract coagulation, ensuring its survival and continued spread. These complex interactions play a crucial role in malaria transmission. Mosquito saliva is represented by yellow dots. Macrogamete and microgamete are the female and male Plasmodium gametes, respectively.

Credit: Image created by Ryan Kissinger, Research and Technologies Branch, NIAID.

Figure 2: Fluorescence microscopy highlights the mosquito salivary gland, a crucial site for malaria transmission. Left: External view. Right: Internal view. The parasite invades this gland, resides in the saliva, and is transmitted during a mosquito bite. This invasion alters salivary gland protein expression and saliva composition. The thin, red-labeled cells form secretory cavities where saliva is produced, surrounding a central cavity (magenta) where saliva and parasites accumulate before reaching the proboscis. Our research investigates how these parasite-induced changes impact transmission and parasite viability.

Credit: Image produced by Dr. Thiago L. Alves e Silva, MPES, NIAID.