Dicrocoelium dendriticum (Trematoda) larvae cause their ant hosts to attach themselves to a plant with their mandibles. Infected ants detach a few hours later, then repeat the attach/detach sequence over subsequent days. Recognition of reversibility in altered host behaviours can enhance our understanding of the general phenomenon of host manipulation.
2 June 2026 marked the centenary of the death of Sir William Boog Leishman, the Scottish physician after whom Leishmania was named. However, he was not the first to describe the parasite. In this article, we recount this discovery and explain the etymological conventions that ensured Leishman's name was preserved in scientific history.
Oxford Nanopore Technology (ONT) direct RNA sequencing enables the sequencing of native RNA molecules without cDNA conversion. The long-read approach captures full-length reads spanning entire genes and has transformed the study of gene expression in Plasmodium parasites by enabling analysis of untranslated regions, isoforms, and alternative splicing. In addition, ONT provides unique insights into non-coding RNAs, RNA modifications, and polyadenylated tail dynamics, which are expanding our understanding of post-transcriptional regulation in Plasmodium, including processes beyond translational repression in gametocytes and sporozoites. Here, we discuss the past and future applications of direct RNA sequencing in Plasmodium research and highlight its advantages, limitations, and future prospects.
The study of biomolecular condensates and other membraneless organelles has shifted the paradigm of cellular organisation, yet their role in parasitic biology remains an emerging field. While model eukaryotes provide the blueprint for phase separation and spatial compartmentalisation, kinetoplastid parasites offer a unique lens through which to explore the functional limits of these 'regulatory hubs'. In this opinion article, we argue that their unconventional biology renders them valuable models for understanding spatial regulation of gene expression. While Trypanosoma brucei serves as the current benchmark, significant gaps remain regarding condensate diversity across other kinetoplastids. We propose a broader investigation into whether these organisms utilise conserved condensates with divergent molecular compositions or entirely novel assemblies to drive their life cycle, pathogenesis, and immune evasion.
Monoclonal antibodies (mAbs) have reshaped prevention and treatment of infectious diseases. However, the development of mAbs against parasitic diseases that disproportionately impact populations in resource-limited settings has received lower priority. Recent trials in Africa show that long-acting mAbs can prevent Plasmodium falciparum infection in children and adults. Early studies suggest that mAb pharmacokinetics differ between malaria-endemic and nonendemic populations, with age and prior parasite exposure possibly affecting the minimum amount of mAb required for durable protection. We present evidence that antiparasitic mAb studies should account for fragment crystallizable receptor polymorphisms and host factors commonly found in endemic populations. We discuss economic and manufacturing barriers to accessing mAbs in resource-limited settings, which have implications for the future use of these promising interventions.
Naturally acquired immunity against cattle ticks, observed in certain breeds of cattle, indicates that development of vaccines to prevent infestations is feasible. This opinion article focuses on the knowledge needed to guide their development, formulation, and testing. It discusses the limitations of current experimental vaccines and tests used to evaluate them and points to the research needed to achieve a truly efficacious vaccine. It includes using better strategies to select antigens, not relying solely on indirect readouts of efficacy but rather elucidating the immune mechanisms responsible for reducing tick loads and overcoming the low coverage of the host’s major histocompatibility complex class II molecules, as well as avoiding confounding factors in designs for testing vaccines and considering management practices that impact efficacy.
Jaundice, caused by the accumulation of bilirubin in plasma, is clinically interpreted as a maladaptive consequence of hemolysis or as indicative of hepatic failure. Drawing on genetic, biochemical, and clinical evidence, we propose to reframe jaundice as an adaptive response to malaria, a hemolytic disease caused by Plasmodium spp. infection. Bilirubin, the molecular basis of jaundice, represents an effector arm of metabolic immunity, distinct from nutritional immunity, which restricts pathogen access to essential nutrients, and from immunometabolism, which shapes immune cell function. In this opinion article, we outline bilirubin's multitarget antiplasmodial mechanisms, define its protective threshold, and discuss its evolutionary implications. We propose metabolite-effector immunity as a broadly applicable framework for host-pathogen biology.
This review provides a state-of-the-art update on Giardia intestinalis pathogenesis and its immunomodulatory effects during enteric coinfections. We examine mechanisms underlying abnormalities in mucus structure and glycosylation, alongside parasite-induced alterations in host immunity. Recent evidence reveals a protective role for gut microbiota biofilms and demonstrates how the Giardia secretome disrupts these communities. In particular, trophozoite-derived cysteine proteases and extracellular vesicles, along with their small RNA cargo, remodel microbiota biofilms and drive the conversion of commensal bacteria into invasive pathobionts. Collectively, these findings establish Giardia as a central regulator of gut microbial ecology and intestinal barrier function, highlighting its value as a model for developing novel therapeutic strategies against enteric disease.
New vaccines to reduce disease and mortality caused by Plasmodium falciparum malaria are urgently needed. Most vaccines target a single life-cycle stage and confer modest protection. Kirtley et al. test whether multistage immunity can improve protection and provide some of the first evidence that ‘multistage’ vaccines should be pursued.
Trypanosoma brucei is an extracellular pathogen that evades the host antibody response through antigenic variation of its variant surface glycoprotein (VSG) coat. It has long been believed that this immune evasion is achieved primarily by replacing the expressed VSG coat with a completely distinct antigen, resulting in complete immune evasion. However, recent evidence suggests that the parasite preferentially diversifies expressed VSGs by introducing small sequence changes through recombination. These modifications appear to accumulate until complete immune evasion is achieved. In this opinion article, we propose that the concepts of antigenic drift and shift, commonly used in the field of influenza research, apply well to antigenic variation in T. brucei and better reflect the complex nature of immune evasion in this pathogen.
Plastic pollution is a global issue. Research on its effects on free-living organisms is growing, but the mechanisms by which micro- and nanoplastics interact with host-parasite systems and their ecological and evolutionary implications remain largely unknown. We propose a framework to better integrate parasites into the context of plastic pollution.
Mosquito olfaction regulates host-seeking, ecological adaptation, and vectorial capacity. Beyond the classical receptor-centric paradigm, we argue that xenobiotic-metabolizing enzymes form a dynamic perireceptor layer that actively sculpts odor identity, signal intensity, and duration. This metabolism gain control mechanism may integrate olfactory sensitivity and behavioral plasticity within a unified sensory framework.
An ectoparasitic mite of the giant honey bees throughout southern and eastern Asia, Tropilaelaps mercedesae has jumped to the western honey bee Apis mellifera and expanded its range, most recently to Eastern Europe. This has rattled an already precarious A. mellifera beekeeping industry, which is grappling with another invasive ectoparasitic mite called Varroa destructor. Here, we review the known biology and pathology of T. mercedesae in its original and novel hosts, discuss current monitoring and treatment options, and identify gaps in knowledge and preparedness. We also compare the natural histories of T. mercedesae and V. destructor to facilitate future directions for research and outreach that promote a timely response to this mite’s growing sphere of influence.
Interleukin-25 (IL-25) has emerged as a central regulator of type 2 immunity at mucosal surfaces. Beyond its classical role as an epithelial alarmin, IL-25 acts as a multifunctional coordinator of epithelial sensing, immune activation, and tissue adaptation during helminth infection. In the intestine, tuft cells detect helminth- and microbiota-derived metabolites and activate a feed-forward circuit with type 2 innate lymphoid cells (ILC2s), promoting antiparasitic immunity and barrier protection. Emerging evidence further links IL-25 to neuroimmune communication, epithelial remodeling, tissue resilience, and disease tolerance. Here, we summarize recent advances in IL-25 biology, including ILC2 specialization and the distinct roles of IL-25 in nematode and trematode infections, highlighting its potential as a therapeutic target to enhance mucosal protection while limiting immunopathology.
Noninvasive approaches are increasingly reshaping parasite and disease surveillance by reducing stress and harm to hosts while expanding opportunities for ecological and epidemiological research. In this opinion article, we discuss these emerging approaches, which rely on molecular, citizen-science, and computational methods, for monitoring parasites, vectors, and hosts. These tools can improve spatial and temporal coverage, support the surveillance of rare or threatened hosts and parasites, and contribute to the understanding of transmission pathways and disease dynamics. However, their reliability depends on careful validation, standardized protocols, and awareness of methodological limitations. While not direct substitutes for invasive methods, these approaches lift a considerable burden from wildlife. Integrating noninvasive approaches thus provides a strong basis for advancing disease ecology, wildlife health monitoring, and biodiversity conservation.
V gamma 9 V delta 2 (Vγ9Vδ2) T cells, the predominant γδ T cell population in human peripheral blood, uniquely recognize nonpeptidic phosphoantigens (pAgs) independent of major histocompatibility complex molecules. This sensing mechanism relies on intracellular pAg accumulation, which triggers heteromeric cooperation between transmembrane butyrophilin 3A1 (BTN3A1) and butyrophilin 2A1 (BTN2A1) receptors to activate the γδ T cell receptor. This review synthesizes current knowledge of Vγ9Vδ2 T cell immunobiology, focusing on responses to Plasmodium falciparum and Toxoplasma gondii. We examine how these cells detect parasite- or host-derived pAgs to drive rapid cytotoxicity and interferon gamma production. Understanding these sensing mechanisms offers novel insights for harnessing γδ T cells in antiparasitic therapies and vaccine design.
Malaria and cancer are major global health burdens, causing high mortality. While often considered distinct, the two conditions share common features, including continuous cell replication within the body, systemic inflammation, immune modulation and evasion, metabolic reprogramming, endothelial dysfunction, and drug efflux mechanisms. Interestingly, whereas malaria parasite infection promotes Burkitt lymphoma, recent studies in animal models indicate that malaria may activate immune mechanisms against various tumors, thereby improving survival rates. The malaria protein VAR2CSA specifically binds to chondroitin sulfate A in the placenta and metastatic cancer cells, which can be exploited for cancer detection and treatment. Studying the common and unique features of malaria and cancer may facilitate the development of treatment strategies for both diseases.
