Biology subjects

Hoque, S. F.

Publications and source records attributed to Hoque, S. F..

8 recordsLinked to original sources

bioRxiv2026

RNA-seq analysis of Triatoma gerstaeckeri during mite infestation reveals increased metabolic demand and lower reproductive investment

Triatomine insects, also known as kissing bugs, serve as vectors for the Trypanosoma cruzi parasite, which can cause American trypanosomiasis, also known as Chagas disease. Triatomines are known to be parasitized by mites in natural and colony settings, where mites feed on the arthropod to obtain nutrients and resources for reproduction. This feeding, while necessary for the survival of the mites, likely occurs at the expense of their insect host. We examined the transcriptional response of Triatoma gerstaeckeri infested with mites (Pimeliaphilus spp.) and an uninfested group using Illumina-based RNA-seq, followed by targeted measurement of nutritional reserves in both groups. Our results show increased expression of factors involved in protein translation, but decreased expression of processes associated with cell development. These results are supported by declines in protein levels in mite-infested T. gerstaeckeri and lower expression of reproductive factors, suggesting a distinct reduction in nutrient reserves and reproductive output. These studies provide critical information on the interaction of mites and triatomines while considering the utility of mites as biological control of triatomines in nature or for husbandry protocols to minimize issues with mite infestations of colony individuals.

physiology↗

bioRxiv2026

Acute Sublethal Heat Stress Impairs Blood Feeding and Trypanosome Infection in the Kissing Bug, Rhodnius prolixus

Kissing bugs are the primary vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Kissing bugs are exposed to thermal variability, including short periods of heat stress, which can induce mortality or exert sublethal effects. This study investigated Rhodnius prolixus following brief periods of high thermal stress with respect to survival, blood feeding, developmental processes, and T. cruzi infection, with a focus on sublethal effects. Our results demonstrated a significant decrease in survival for R. prolixus at 42 {degrees}C for 8 hours. When exposed to sub-lethal thermal stress (40{degrees}C for 8 hours), blood ingestion (amount and proportion) was reduced after 24 hours of recovery from thermal stress. Among the bugs that fed after 24 hours, molting was not impacted by temperature exposure. The infection rate decreased after heat exposure, likely due to reduced blood volume ingested when feeding 24 hours after heat stress. A week of recovery after exposure to higher temperatures improved feeding and increased infection rates to levels comparable to those of kissing bugs not exposed to thermal stress. Our findings offer insights into how extreme temperature events may influence Chagas disease. Specifically, these studies highlight the need to clarify how temperature, particularly at sublethal levels, interacts with vector biology to alter parasite transmission.

physiology↗

bioRxiv2025

Cyclic AMP compartmentalization drives signal specificity to control vector colonization and mammalian host infection by American trypanosomes

Cyclic AMP (cAMP) signaling is crucial for environmental sensing and response to stress conditions in trypanosomatids. However, the mechanisms driving the specificity of cAMP signals remain poorly understood in these protozoan parasites. We recently identified two putative cAMP microdomains in Trypanosoma cruzi, the causative agent of Chagas disease. Here, considering the localization of three phosphodiesterases, PDEC at the contractile vacuole complex (CVC), and PDEB1 and PDEB2 along the flagellum, we modulated their expression to functionally characterize the flagellar tip (FT) and the CVC as individual cAMP microdomains, named FT-cAMP and CVC-cAMP, respectively. We generated PDE knockout and overexpression cell lines to selectively alter cAMP signals generated in each compartment. Our results indicate that FT-cAMP mediates cell adhesion, metacyclogenesis, host cell invasion, and intracellular replication, while CVC-cAMP is required for osmoregulation and epimastigote proliferation. In addition, ablation of flagellar PDEB1 and PDEB2 enhanced the parasites ability to colonize the hindgut of the triatomine vector, whereas PDEC-KO parasites were impaired in their establishment in the insects hindgut. The observed phenotypes were compartment-specific, demonstrating functional segregation between the two cAMP microdomains. Our data provide robust evidence on the presence of compartmentalized cAMP signals in T. cruzi, linking the role of locally synthesized cAMP pools to specific cellular responses during the parasites life cycle. Author summaryChagas disease is a life-threatening infectious disease caused by the protozoan parasite Trypanosoma cruzi, which is spread through the feces of infected kissing bugs. The parasite survives in challenging environments as it transitions between the insect vector and the mammalian host by differentiating into distinct developmental forms. cAMP is a universal second messenger that mediates specific cellular processes in the life cycle of T. cruzi. However, the spatial-temporal dynamics of cAMP signal remain largely unexplored in trypanosomes. We previously reported several cAMP signaling proteins in two compartments of T. cruzi: the contractile vacuole complex (CVC) and the flagellar tip (FT). In this study, we characterized the individual functions of these microdomains. We specifically disturbed cAMP signaling in these compartments by modulating the expression of their resident phosphodiesterases. We observed that the FT microdomain is specifically involved in parasite differentiation, host cell invasion, intracellular replication, and vector colonization, while the CVC microdomain is important for osmoregulation and parasite survival within the kissing bug. Our results unequivocally demonstrate that T. cruzi utilizes specific cAMP pools to address different environmental challenges. These findings highlight cAMP signaling as an essential pathway that could be further explored for the development of novel antiparasitic interventions.

cell biology↗

bioRxiv2024

TcCARP3 modulates compartmentalized cAMP signals involved in osmoregulation, infection of mammalian cells, and colonization of the triatomine vector in the human pathogen Trypanosoma cruzi

Trypanosoma cruzi is the causative agent of Chagas disease, a zoonotic infectious disease considered a leading cause of cardiomyopathy, disability, and premature death in the Americas. This parasite spends its life between a mammalian host and an arthropod vector, undergoing essential transitions among different developmental forms. How T. cruzi senses microenvironmental changes that trigger cellular responses necessary for parasite survival has remained largely unknown. Cyclic AMP (cAMP) is a universal second messenger that has been shown to regulate key cellular processes in trypanosomes, in which cyclic AMP response proteins (CARPs) have been proposed to be modulators or effectors of a PKA-independent signaling pathway. In this study we aimed to investigate the role of TcCARP3 in cAMP signaling throughout T. cruzi life cycle. Our results show that TcCARP3 shares a dual localization (flagellar tip and contractile vacuole complex) with adenylate cyclase 1 (TcAC1) in the main developmental stages of the parasite. We also found that TcCARP3 directly interacts with several TcACs, modulating the intracellular content of cAMP. Through generation of TcCARP3 knockout, addback, and overexpression cell lines we showed that modulation of gene expression affects the parasites ability to differentiate, respond to osmotic stress, invade mammalian cells and replicate within them, and colonize the hindgut of the triatomine vector. In addition, we identified several signaling proteins interacting with TcCARP3 in what we propose are cAMP signaling microdomains. Our results unveil a key role for TcCARP3 as modulator of cAMP signals necessary for parasite differentiation and survival throughout T. cruzi life cycle. IMPORTANCECyclic AMP signaling pathways are poorly understood in the stercorarian parasite Trypanosoma cruzi. Specifically, the mechanisms driving the activation of TcACs in response to microenvironmental stress are completely unknown. This study unveils the role of TcCARP3 in modulating the content of cAMP through the interaction with several TcACs and putative cAMP effectors in T. cruzi. Particularly, TcCARP3 interacts with TcAC1 in the main developmental stages of this parasites life cycle, where both proteins display a dual localization pattern. These results provide new evidence supporting the compartmentalization of cAMP signals in trypanosomes. Moreover, our data unequivocally demonstrates that TcCARP3 is required for key cellular processes for parasite survival, such as response to osmotic stress, host cell invasion, intracellular replication, and the ability to colonize the hindgut of the triatomine vector. In summary, we found that TcCARP3 is an adenylate cyclase regulator, necessary for the life cycle progression of T. cruzi.

microbiology↗

bioRxiv2024

Impaired humidity sensing reduces tick survival by preventing water homeostasis

Off-host periods are critical for ticks, representing a time when environmental stress, particularly dehydration, can impact tick survival. To prevent dehydration, ticks must be able to detect and move into high humidity areas to allow for water vapor uptake. Ionotropic receptor 93a (Ir93a), which is highly expressed in the front forelegs (location of Hallers organ), increases expression following dehydration, suggesting a role for the forelegs in humidity detection. Although the Hallers organ is suggested as the site of humidity detection in ticks, humidity detection has not been extensively examined for ticks. Here, we assessed the ability of ticks to sense humidity and how altered humidity detection impacts tick survival by manipulating the Hallers organ. Permanent (cutting or heat ablation) or temporary blocking (silicone covering) of the Hallers organ impairs the ability of the American dog tick, Dermacentor variabilis, to rest in areas necessary to maintain hydration. Impaired detection of humidity did not impact tick survival when individuals were held under stable optimal conditions. Still, variable conditions (low and high humidity gradient) reduced survival through dehydration stress and decreased energy reserves, as chronic water vapor uptake is energetically expensive. Field validation of these studies in D. variabilis confirmed that humidity detection is critical to tick survival. Lastly, modeling indicates impaired humidity detection will reduce questing tick populations, specifically in the adult stages. These studies confirm that the Hallers organ is critical for humidity sensing in ticks. Without this ability, tick survival will be impaired by potential dehydration or more rapid depletion of energy reserves.

physiology↗

bioRxiv2020

In silico Identification and Functional Characterization of Conserved miRNAs in Fibre Biogenesis Crop Corchorus capsularis

Corchorus capsularis, commonly known as jute occupies the leading position in the production of natural fibre and fibre based products alongside lower environmental threat. Nowadays, the study of lignin biosynthesis pathways with other molecular basis of fibres formation are being more focused for its economic perspective. Small noncoding [~]21 to 24 nt nucleotides long microRNAs play significant roles in regulating the gene expression as well as different functions in cellular growth and development. Here, the study adopted a comprehensive in silico approach to identify and characterize the conserved miRNAs in the genome of C. capsularis including specific gene targets involved in the crucial cellular process. Expressed Sequence Tags (ESTs) based homology search of 3350 known miRNAs of dicotyledons were allowed against 763 non-redundant ESTs of jute genome resulted in the prediction of 5 potential miRNA candidates belonging five different miRNA families (miR1536, miR9567-3p, miR4391, miR11300, and miR8689). The putative miRNAs were 18 nucleotide length, within a range of -0.49 to -1.56 MFEI values and 55% to 61% of (A+U) content of their correspondence pre-miRNAs. A total of 1052 gene targets of putative miRNAs were identified and their functions were extensively analyzed. Most of the gene targets were involved in plant growth, cell cycle regulation, organelle synthesis, developmental process and environmental responses. The five gene targets, namely, NAC Domain Containing Protein, WRKY DNA binding protein, 3-dehydroquinate synthase, S-adenosyl-L-Met-dependent methyl transferase and Vascular-related NAC-Domain were found to be involved in the lignin biosynthesis, phenylpropanoid pathways and secondary wall formation which could play significant roles in the overall fibre biogenesis. The characterization of conserved miRNAs and their functional annotation of specific gene targets might enhance the more miRNA discovery, strengthening the complete understanding of miRNAs association in the cellular basis of lignin biosynthesis towards the production of high standard jute products.

genomics↗

bioRxiv2020

Genome based Evolutionary study of SARS-CoV-2 towards the Prediction of Epitope Based Chimeric Vaccine

SARS-CoV-2 is known to infect the neurological, respiratory, enteric, and hepatic systems of human and has already become an unprecedented threat to global healthcare system. COVID-19, the most serious public condition caused by SARS-CoV-2 leads the world to an uncertainty alongside thousands of regular death scenes. Unavailability of specific therapeutics or approved vaccine has made the recovery of COVI-19 more troublesome and challenging. The present in silico study aimed to predict a novel chimeric vaccines by simultaneously targeting four major structural proteins via the establishment of ancestral relationship among different strains of coronaviruses. Conserved regions from the homologous protein sets of spike glycoprotein (S), membrane protein (M), envelope protein and nucleocapsid protein (N) were identified through multiple sequence alignment. The phylogeny analyses of whole genome stated that four proteins (S, E, M and N) reflected the close ancestral relation of SARS-CoV-2 to SARS-COV-1 and bat coronavirus. Numerous immunogenic epitopes (both T cell and B cell) were generated from the common fragments which were further ranked on the basis of antigenicity, transmembrane topology, conservancy level, toxicity and allergenicity pattern and population coverage analysis. Top putative epitopes were combined with appropriate adjuvants and linkers to construct a novel multiepitope subunit vaccine against COVID-19. The designed constructs were characterized based on physicochemical properties, allergenicity, antigenicity and solubility which revealed the superiority of construct V3 in terms safety and efficacy. Essential molecular dynamics and Normal Mode analysis confirmed minimal deformability of the refined model at molecular level. In addition, disulfide engineering was investigated to accelerate the stability of the protein. Molecular docking study ensured high binding affinity between construct V3 and HLA cells, as well as with different host receptors. Microbial expression and translational efficacy of the constructs were checked using pET28a(+) vector of E. coli strain K12. The development of preventive measures to combat COVID-19 infections might be aided the present study. However, the in vivo and in vitro validation might be ensured with wet lab trials using model animals for the implementation of the presented data.

immunology↗

bioRxiv2020

Scrutinizing surface glycoproteins and poxin-schlafen protein to design a heterologous recombinant vaccine against monkeypox virus

Monkeypox is a zoonotic disease caused by monkeypox virus with noteworthy mortality and morbidity. Several recent outbreaks and the need of dependable reconnaissance have raised the level of concern for this developing zoonosis. In the present study, a reverse vaccinology strategy was developed to construct a peptide vaccine against monkeypox virus by exploring cell surface binding protein, Poxin-Schlafen andenvelope protein. Both humoral and cell mediated immunity induction were the main concerned properties for the designed peptide vaccine. Therefore, both T cell and B cell immunity against monkeypox virus were analyzed from the conserver region of the selected protein. Antigenicity testing, transmembrane topology screening, allergenicity and toxicity assessment, population coverage analysis and molecular docking approach were used to create the superior epitopes of moneypox virus. The subunit vaccine was constructed using highly immunogenic epitopes with appropriate adjuvant and linkers. Molecular docking examination of the refined vaccine with various MHCs and human immune receptor illustrated higher binding interaction. The designed construct was reverse transcribed and adjusted for E. coli strain K12 earlier to inclusion inside pET28a(+) vector for its heterologous cloning and expression. The study could start in vitro and in vivo studies concerning effective vaccine development against monkeypox virus.

bioinformatics↗