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Palmieri, E.

Publications and source records attributed to Palmieri, E..

2 recordsLinked to original sources

Integral membrane protein, anchor, is expressed in the Drosophila insulin-producing cells and is a novel modulator of homeostatic behaviors, including sleep, feeding, and sedation

Integral membrane proteins (IMPs) are central regulators of cellular signaling and represent a major class of therapeutic targets. GPR155 (also known as LYCHOS), an evolutionarily conserved protein containing both transporter-like and GPCR-like domains, has recently emerged as a lysosomal nutrient sensor implicated in mTORC1 signaling. Despite its enriched expression in brain regions associated with reward processing, the in vivo neuronal and behavioral functions of GPR155 remain undefined. Here, we leverage the genetic tractability of Drosophila melanogaster to characterize the role of the GPR155 ortholog, anchor, in neural circuit function and behavior. Here, we demonstrate that pan-neuronal downregulation of anchor leads to significant alterations in multiple behaviors, including reduced feeding, disrupted light-dependent rhythmicity, decreased sleep, increased waking locomotor activity, and diminished sedation sensitivity to ethanol. We also selectively manipulated anchor expression in the neuroendocrine insulin-producing cells (IPCs), which phenocopied impaired rhythmicity and decreased ethanol sedation sensitivity observed in pan-neuronal manipulations, indicating that anchor function within IPCs is sufficient to modulate discrete behavioral outputs. Our results suggest that anchor regulates behavior in a sexually dimorphic manner as changes in ethanol sedation sensitivity were more penetrant in females, whereas altered feeding and ethanol preference was observed only in males. These findings establish a previously unrecognized role for anchor in the regulation of neuroendocrine signaling and behavior. Given the conservation of mTORC1 signaling and neuropeptidergic systems across species, this work provides mechanistic insight into how multifunctional IMPs integrate metabolic and environmental cues to influence complex behaviors, with potential implications for understanding the molecular basis of feeding, sleep regulation, and substance use disorders.

neuroscience↗

Vi polysaccharide and conjugated vaccines afford similar early, IgM or IgG-independent control of infection but boosting with conjugated Vi vaccines sustains the efficacy of immune responses

Vaccination with Vi capsular polysaccharide (Vi-PS) or protein-Vi typhoid conjugate vaccine (TCV) can protect adults against Salmonella Typhi infections. TCVs offer better protection than Vi-PS in infants and may offer better protection in adults. Potential reasons for why TCV may be superior in adults are not fully understood. Here, we immunized wild-type (WT) mice and mice deficient in IgG or IgM with Vi-PS or TCVs (Vi conjugated to tetanus toxoid or CRM197) for up to seven months, with and without subsequent challenge with Vi-expressing Salmonella Typhimurium. Unexpectedly, IgM or IgG alone were similarly able to reduce bacterial burdens in tissues, and this was observed in response to conjugated or unconjugated Vi vaccines and was independent of antibody being of high affinity. Only in the longer-term after immunization (>5 months) were differences observed in tissue bacterial burdens of mice immunized with Vi-PS or TCV. These differences related to the maintenance of antibody responses at higher levels in mice boosted with TCV, with the rate of fall in IgG titres induced to Vi-PS being greater than for TCV. Therefore, Vi-specific IgM or IgG are independently capable of protecting from infection and any superior protection from vaccination with TCV in adults may relate to responses being able to persist better rather than from differences in the antibody isotypes induced. These findings suggest that enhancing our understanding of how responses to vaccines are maintained may inform on how to maximize protection afforded by conjugate vaccines against encapsulated pathogens such as S. Typhi.

immunology↗