Vesicle adaptors are critical for transport of proteins to the correct cellular destination. In malaria parasites general and specialized organelles depend on faithful protein transport to mediate host cell invasion and for intracellular survival. However, the role of adaptors in the parasite and the comparability of the sorting machinery with model organisms are unclear. Here, we show that AP-1, AP-3, and AP-4 are all important for parasite survival. AP-1 was needed for intracellular growth, biogenesis of specialized invasion organelles, and formation of invasive progeny, while AP-3 and AP-4 were both required for invasion into host cells. AP-1 acted through the multi-ligand receptor sortilin while AP-4 sorted multi-transmembrane proteins. Proxiomes from live cells revealed remarkable similarities of the configuration of the adaptor sorting machinery between the parasite and evolutionarily distant model organisms, but also unconventional features such as tepsin functioning with AP-1 and clathrin with AP-4. This work reveals unexpected exchangeability of key elements in otherwise surprisingly conserved adaptor sorting pathways.

Monocytes are key modulators in acute viral infections, determining both inflammation and development of specific B- and T-cell responses. Recently, these cells were shown to be associated to different SARS-CoV-2 infection outcome. However, their role in acute HIV-1 infection remains unclear. We had the opportunity to evaluate the mononuclear cell compartment in an early hyper-acute HIV-1 patient in comparison with an untreated chronic HIV-1 and a cohort of SARS-CoV-2 infected patients, by high dimensional flow cytometry using an unsupervised approach. A distinct polarization of the monocyte phenotype was observed in the two viral infections, with maintenance of pro-inflammatory M1-like profile in HIV-1, in contrast to the M2-like immunosuppressive shift in SARS-CoV-2. Noticeably, both acute infections had reduced CD14^low/−CD16⁺ non-classical monocytes, with depletion of the population expressing Slan (6-sulfo LacNac), which is thought to contribute to immune surveillance through pro-inflammatory properties. This depletion indicates a potential role of these cells in acute viral infection, which has not previously been explored. The inflammatory state accompanied by the depletion of Slan+ monocytes may provide new insights on the critical events that determine the rate of viral set-point in acute HIV-1 infection and subsequent impact on transmission and reservoir establishment.

XLA patient with 7‐month course of COVID‐19 with persistent plasma SARS‐CoV‐2 load revealed a sustained non‐inflammatory profile of myeloid cells in association with contained severity of disease, arguing in favor of the use of BTK inhibitors in SARS‐COV‐2 infection.

Mature gametocytes of Plasmodium falciparum exhibit a characteristic falciform shape, which is conferred by a complex array of subpellicular microtubules (SPMTs) associated with the inner membrane complex (IMC). While several microtubule-associated proteins (MAPs) have been characterized in the related apicomplexan parasite Toxoplasma gondii , the identity and function of MAPs in Plasmodium remain poorly understood. Here, we employed proximity-dependent biotinylation (BioID) using Pf SPM3, a subpellicular MAP, as a bait in order to identify proteins associated with P. falciparum gametocyte SPMTs. Mass spectrometry analysis revealed 37 high-confidence proteins in the immediate vicinity of Pf SPM3 constituting its “proxiome.” Using GFP tags on the endogenous proteins of 11 highly enriched candidates, we provide a spatial localization atlas of previously uncharacterized proteins. Notably, many of these putative MAPs showed a distinct localization to different structures within the SPMT network, highlighting its complexity in developing gametocytes. Among these, we demonstrate that functional knockout of one MAP, PF3D7_1003400, which exhibits a localization pattern consistent with positioning near the IMC suture/SPMT boundary, interferes with gametocytogenesis and prevents falciform gametocyte development. These findings provide the first atlas of the SPMT network required to coordinate cytoskeletal dynamics, IMC organization, and gametocyte development. Understanding these interactions offers new avenues for blocking gametocyte cytoskeleton development and malaria transmission. IMPORTANCE: Transmission of Plasmodium falciparum relies on the formation of falciform gametocytes, a process dependent on the dynamic interplay between subpellicular microtubules (SPMTs) and the inner membrane complex (IMC). In this study, we employed proximity-dependent biotinylation using Pf SPM3, an SPMT-associated protein, as a bait. We present a comprehensive list of highly enriched proteins and a validation of the top candidates revealing novel components of the cytoskeleton of gametocytes that might play a role in their morphogenesis and transmission.

Protein complexes are central to all cellular processes and their regulation. Here, we introduce the meltome-assisted profiling of protein complexes (MAP-X) that maps the complexome through thermal proteome profiling in the native environment. Applied across blood stages of malaria parasite P. falciparum, MAP-X resolved conserved protein complexes, reproduced previously identified interactions and found new associations. Among those, we discovered the missing subunits of the RNA exosome and reconstructed its structure, and further experimentally validated the interactions of the exported protein PF3D7_1149100; putative subunits of MON1-CCZ1 complex and its regulator; and promiscuous interactions between proteins Alba 1-4. Finally, we found that malaria protein complexes undergo distinct dynamic alterations across the blood stages and predicted their moonlighting subunits. Altogether, MAP X represents a highly efficient and operational method for characterizing protein complexes in intact cells that can be rapidly deployed to study cellular physiology proteome-wide in various cellular systems and conditions.