Repeated sensitization of mice with microfilariae of Litomosoides sigmodontis induces pulmonary eosinophilia in an IL-33-dependent manner.

BACKGROUND: Eosinophilia is a hallmark of helminth infections and eosinophils are essential in the protective immune responses against helminths. Nevertheless, the distinct role of eosinophils during parasitic filarial infection, allergy and autoimmune disease-driven pathology is still not sufficiently understood. In this study, we established a mouse model for microfilariae-induced eosinophilic lung disease (ELD), a manifestation caused by eosinophil hyper-responsiveness within the lung. METHODS: Wild-type (WT) BALB/c mice were sensitized with dead microfilariae (MF) of the rodent filarial nematode Litomosoides sigmodontis three times at weekly intervals and subsequently challenged with viable MF to induce ELD. The resulting immune response was compared to non-sensitized WT mice as well as sensitized eosinophil-deficient dblGATA mice using flow cytometry, lung histology and ELISA. Additionally, the impact of IL-33 signaling on ELD development was investigated using the IL-33 antagonist HpARI2. RESULTS: ELD-induced WT mice displayed an increased type 2 immune response in the lung with increased frequencies of eosinophils, alternatively activated macrophages and group 2 innate lymphoid cells, as well as higher peripheral blood IgE, IL-5 and IL-33 levels in comparison to mice challenged only with viable MF or PBS. ELD mice had an increased MF retention in lung tissue, which was in line with an enhanced MF clearance from peripheral blood. Using eosinophil-deficient dblGATA mice, we demonstrate that eosinophils are essentially involved in driving the type 2 immune response and retention of MF in the lung of ELD mice. Furthermore, we demonstrate that IL-33 drives eosinophil activation in vitro and inhibition of IL-33 signaling during ELD induction reduces pulmonary type 2 immune responses, eosinophil activation and alleviates lung lacunarity. In conclusion, we demonstrate that IL-33 signaling is essentially involved in MF-induced ELD development. SUMMARY: Our study demonstrates that repeated sensitization of BALB/c mice with L. sigmodontis MF induces pulmonary eosinophilia in an IL-33-dependent manner. The newly established model recapitulates the characteristic features known to occur during eosinophilic lung diseases (ELD) such as human tropical pulmonary eosinophilia (TPE), which includes the retention of microfilariae in the lung tissue and induction of pulmonary eosinophilia and type 2 immune responses. Our study provides compelling evidence that IL-33 drives eosinophil activation during ELD and that blocking IL-33 signaling using HpARI2 reduces eosinophil activation, eosinophil accumulation in the lung tissue, suppresses type 2 immune responses and mitigates the development of structural damage to the lung. Consequently, IL-33 is a potential therapeutic target to reduce eosinophil-mediated pulmonary pathology.

Exploring the antifilarial potential of an important medicinal plant Typhonium trilobatum (L. Schoot): Isolation, characterization, and structural elucidation of bioactive compounds against Brugia malayi.

ETHNOPHARMACOLOGY RELEVANCE: The plant Typhonium trilobatum has been utilized in traditional medicine for the treatment of many ailments, including parasitic infections. Recent examinations indicate that the bioactive substances from this plant may have antiparasitic activities against Brugia malayi, which have not been determined. PURPOSE: The parasitic nematodes Brugia malayi, Brugia timori, and Wuchereria bancrofti causing lymphatic filariasis, remain a significant challenge to global public health. Given the ongoing nature of this enduring menace, the current research endeavours to examine the efficacy of an important medicinal plant, Typhonium trilobatum. METHODS: Different extracts of the T. trilobatum tubers were evaluated for their antiparasitic activity. The most prominent extract was subjected to Gas Chromatography Mass Spectrometry (GC-MS) and High Performance Liquid Chromatography (HPLC) followed by Column Chromatography for isolating bioactive molecules. The major compounds were isolated and characterized based on different spectroscopic techniques (FTIR, NMR and HRMS). Further, the antiparasitic activity of the isolated compounds was evaluated against B. malayi and compared with clinically used antifilarial drugs like Diethylcarbamazine and Ivermectin. RESULTS: The methanolic extract of the tuber exhibited significant antiparasitic activity compared to the other extracts. The bioactive molecules isolated from the crude extract were identified as Linoleic acid and Palmitic acid. Antiparasitic activity of both the compounds has been performed against B. malayi and compared with clinically used antifilarial drugs, Ivermectin and DEC. The IC50 value of Linoleic acid was found to be 6.09 ± 0.78 µg/ml after 24 h and 4.27 ± 0.63 µg/ml after 48 h, whereas for Palmitic acid the value was 12.35 ± 1.09 µg/ml after 24 h and 8.79 ± 0.94 µg/ml after 48 h. The IC50 values of both the molecules were found to be similar to the standard drug Ivermectin (IC50 value of 11.88 ± 1.07 µg/ml in 24 h and 2.74 ± 0.43 µg/ml in 48 h), and much better compared to the DEC (IC50 values of 194.2 ± 2.28 µg/ml in 24 h and 101.8 ± 2.06 µg/ml in 48 h). Furthermore, it has been observed that both the crude extracts and the isolated compounds do not exhibit any detrimental effects on the J774.A.1 macrophage cell line. CONCLUSION: The isolation and characterization of bioactive compounds present in the methanolic tuber extract of Typhonium trilobatum were explored. Moreover, the antimicrofilarial activity of the crude extracts and its two major compounds were determined using Brugia malayi microfilarial parasites without any significant side effects.

Cerebral filariasis infection with Litomosoides in Molossus barnesi (Chiroptera: Molossidae) in the Brazilian eastern Amazon, with comments on Molossinema wimsatti Georgi, Georgi, Jiang and Fronguillo, 1987.

During bacterial and viral pathogen investigation of 30 specimens of bats captured in periurban forest areas in the city of Belém, Pará, Brazil, a case of cerebral filariasis was observed. In the course of histopathological examination, adult filariae were found in pseudocystic cavities brain of Molossus barnesi (Molossidae) and classified morphologically as Litomosoides by the shape of the spicules-left spicule with a handle longer than the blade; right spicule curved, with a sclerotized heel supporting a dorsal notch; the area rugosa constituted by a ventral band of small longitudinal crests; tail rounded in males; long esophagus with a slightly glandular distal portion; and a muscular bent vagina. All the specimens lack a stoma (buccal capsule). We compared our filarioids with the description of specimens of Molossinema wimsatti. Morphological characteristics of M. wimsatti resemble the genus Litomosoides. Thus, we believe that M. wimsatti is a synonym of L. molossi Esslinger, 1973, and filarioid specimens from material reported by Lichtenfels et al. (Trans Am Micros Soc 100:216-219, 1981) and from de Souto et al. (J. Helminthol 1195:e65, 2021) most probably correspond to Litomosoides. We suggest that the reduction of the buccal capsule may be attributable to the ectopic location. No evidence of tissue responses by the host was observed. This is the first record of Litomosoides infecting brain tissue of Molossus barnesi from Brazil, representing a record of a new host species. More specimens of bats should be examined in order to find filarioids in the brain and verify its taxonomic position using molecular techniques.

A Giant Scrotal Neurofibroma in a Child Masquerading as Filariasis: Uncommon Presentation of a Common Disease.

Neurofibroma of the scrotum is a very uncommon benign neoplasm, specifically when it affects teenagers and is not associated with neurofibromatosis type I. To the best of our knowledge, only a couple of cases of neurofibroma in children have been documented. Here, we report a case study of a 17-year-old boy who had a giant scrotal lump for ten years masquerading clinically as filariasis. A provisional diagnosis of benign nerve sheath neoplasm was made based on cytology findings. The lump was surgically removed from the patient, and a histopathological and immunohistochemistry examination established the diagnosis of neurofibroma. The combined clinical, preoperative cytological, histological, and immunohistochemistry findings were not presented in the literature in any of the formerly documented cases of scrotal neurofibroma. The current case expands the spectrum of differential diagnoses for scrotal tumours that clinicians have previously observed.

Development and validation of a long-read metabarcoding platform for the detection of filarial worm pathogens of animals and humans.

BACKGROUND: Filarial worms are important vector-borne pathogens of a large range of animal hosts, including humans, and are responsible for numerous debilitating neglected tropical diseases such as, lymphatic filariasis caused by Wuchereria bancrofti and Brugia spp., as well as loiasis caused by Loa loa. Moreover, some emerging or difficult-to-eliminate filarioid pathogens are zoonotic using animals like canines as reservoir hosts, for example Dirofilaria sp. 'hongkongensis'. Diagnosis of filariasis through commonly available methods, like microscopy, can be challenging as microfilaremia may wane below the limit of detection. In contrast, conventional PCR methods are more sensitive and specific but may show limited ability to detect coinfections as well as emerging and/or novel pathogens. Use of deep-sequencing technologies obviate these challenges, providing sensitive detection of entire parasite communities, whilst also being better suited for the characterisation of rare or novel pathogens. Therefore, we developed a novel long-read metabarcoding assay for deep-sequencing the filarial nematode cytochrome c oxidase subunit I gene on Oxford Nanopore Technologies' (ONT) MinION™ sequencer. We assessed the overall performance of our assay using kappa statistics to compare it to commonly used diagnostic methods for filarial worm detection, such as conventional PCR (cPCR) with Sanger sequencing and the microscopy-based modified Knott's test (MKT). RESULTS: We confirmed our metabarcoding assay can characterise filarial parasites from a diverse range of genera, including, Breinlia, Brugia, Cercopithifilaria, Dipetalonema, Dirofilaria, Onchocerca, Setaria, Stephanofilaria and Wuchereria. We demonstrated proof-of-concept for this assay by using blood samples from Sri Lankan dogs, whereby we identified infections with the filarioids Acanthocheilonema reconditum, Brugia sp. Sri Lanka genotype and zoonotic Dirofilaria sp. 'hongkongensis'. When compared to traditionally used diagnostics, such as the MKT and cPCR with Sanger sequencing, we identified an additional filarioid species and over 15% more mono- and coinfections. CONCLUSIONS: Our developed metabarcoding assay may show broad applicability for the metabarcoding and diagnosis of the full spectrum of filarioids from a wide range of animal hosts, including mammals and vectors, whilst the utilisation of ONT' small and portable MinION™ means that such methods could be deployed for field use.

Camel filariasis (Dipetalonema evansi) and its association with clinical balanoposthitis with reference to prominent changes in clinical findings, serum testosterone, semen analysis, and testicular histopathology.

BACKGROUND: Camel filariasis induced variable clinical syndromes characterized by fever, lethargy, localized dermal lesions, loss of condition, and testicular and scrotal swelling. The objective of the present work focused on clarifying the diagnostic importance of clinical findings, serum testosterone, and semen analysis as well as blood smear and testicular histopathology as a differential tool between only balanoposthitis without filariasis male camels group (OnlyBpgr) and balanoposthitis-filariasis infected male camels group (BpFlgr). The study also monitored the associations between the severity of ticks' infestations in investigated male camels and the occurrence of balanoposthitis only or balanoposthitis with filariasis. RESULTS AND CONCLUSIONS: The study reported significant correlation between serum testosterone, serum cortisol, and sperm vitality and abnormalities percentages. The study included male camels (n = 250) classified into three groups: healthy control group (Contgr; n = 30), OnlyBpgr (n = 210), and BpFlgr (n = 10). These male camels were clinically and laboratory examined, and skin scraping tests and testicular histopathology were conducted. The study confirmed the association of the changes in clinical findings, whole blood picture, serum testosterone, serum cortisol, and semen analysis, with OnlyBpgr and BpFlgr. These changes were more prominent in BpFlgr than in OnlyBpgr. Skin scraping test results revealed a higher severity of live ticks' infestation in BpFlgr than in OnlyBpgr because, unlike OnlyBpgr, all camels in BpFlgr (n = 10) were suffering from live ticks' infestation. It also concluded the higher efficacy of histopathology of testicular tissues in male camels as a diagnostic tool for adult filaria in balanoposthitis-affected male camels than blood smear because all cases of camel filariasis in the current work were negative for microfilaria on microscopic examination of diurnal blood smear as well as testicular histopathology revealed detection of adult filaria in all camel filariasis associated with balanoposthitis. Strong correlation relationships were demonstrated between serum testosterone, serum cortisol, and semen analysis results. Positive correlations were reported between serum testosterone levels and sperm vitality percentages. However, negative correlations were stated between serum testosterone and each of serum cortisol and sperm abnormalities either in Contgr, OnlyBpgr, or BpFlgr.

Stigma, depression and quality of life among people affected by neglected tropical diseases in Nepal.

BACKGROUND: Stigma and poor mental health are important factors influencing the quality of life (QOL) of people with neglected tropical diseases (NTDs). This study examines the relationship between stigma, depression and QOL among people affected by leprosy and lymphatic filariasis (LF) in Nepal. METHODS: A cross-sectional community-based survey was conducted among 102 NTD-affected persons (70 leprosy and 32 LF) using interview-administered questionnaires measuring the level of stigma (5-QSI-AP), symptoms of depression (PHQ-9) and QOL (WHOQOL-8). Three different regression models were developed, each using the ordinary least squares and Poisson regression to evaluate the association between stigma and QOL, depression and QOL, and stigma and depression. RESULTS: The mean scores were 21.8±4.4 for QOL, 6.6±5.6 for depression and 3.0±2.8 for stigma. Almost 17% reported the prevalence of depression symptoms. Both stigma (ß=-0.65, p<0.001) and depression (ß=-0.32, p<0.001) were associated with lower scores for QOL, while there was a significant positive relationship between stigma and depression (ß=0.92, p<0.001). Similar results were obtained from the Poisson regression models. CONCLUSIONS: The study showed a considerable burden of depression, stigma and poor QOL among study participants with leprosy and LF in Nepal. A holistic package of care that addresses the physical, mental and psychological well-being of people with NTD is required. CONTEXTE: La stigmatisation et la mauvaise santé mentale sont des facteurs importants qui influencent la qualité de vie des personnes atteintes de maladies tropicales négligées (MTN). Cette étude examine la relation entre la stigmatisation, la dépression et la qualité de vie chez les personnes atteintes de lèpre et de filariose lymphatique au Népal. MÉTHODES UTILISÉES: Une enquête communautaire transversale a été menée auprès de 102 personnes atteintes de MTN (70 de la lèpre et 32 de la filariose lymphatique) à l'aide de questionnaires administrés par entretien mesurant le niveau de stigmatisation (5-QSI-AP), les symptômes de dépression (PHQ-9) et la qualité de vie (WHOQOL-8). Trois modèles de régression différents ont été développés, chacun utilisant les moindres carrés ordinaires et la régression de Poisson pour évaluer l'association entre : (i) la stigmatisation et la QV; (ii) la dépression et la QV; et (iii) la stigmatisation et la dépression. RÉSULTATS: Les scores moyens étaient de 21,8±4,4 pour la QV, 6,6±5,6 pour la dépression, et 3,0±2,8 pour la stigmatisation. Près de 17% des personnes interrogées ont signalé la prévalence de symptômes dépressifs. La stigmatisation (ß = -0,65, p<0 001) et la dépression (ß = -0,32, p<0 001) ont été associées à des scores plus faibles pour la qualité de vie, tandis qu'il existait une relation positive significative entre la stigmatisation et la dépression (ß = 0,92, p<0 001). Des résultats similaires ont été obtenus à partir des modèles de régression de Poisson. CONCLUSIONS: L'étude a montré une incidence importante de dépression, de stigmatisation et d'une mauvaise qualité de vie parmi les participants atteints de lèpre et de FL au Népal. Il convient donc de mettre en place un ensemble de soins holistiques pour ces patients qui prendrait en compte le bien-être physique, mental et psychologique des personnes atteintes de MTN. ANTECEDENTES: La estigmatización y la mala salud mental son factores importantes que influyen en la calidad de vida de las personas con enfermedades tropicales desatendidas. las personas con enfermedades tropicales desatendidas (ETD). Este estudio examina la relación entre el estigma, la depresión y la CdV entre las personas afectadas por lepra y lepra y la filariasis linfática en Nepal. MÉTODOS: Se realizó una encuesta comunitaria transversal entre 102 personas afectadas por ETD (70 de lepra y 32 de filariasis linfática) utilizando cuestionarios entrevistas para medir el nivel de estigma (5-QSI-AP), los síntomas de depresión (PHQ- 9) y la CdV (OMS- 9). 9) y la calidad de vida (WHOQOL-8). Se desarrollaron tres modelos de regresión diferentes regresión de Poisson para evaluar la asociación entre: (i) el estigma y (ii) la depresión. entre: (i) estigma y CdV; (ii) depresión y CdV; y (iii) estigma y depresión. RESULTADOS: Las puntuaciones medias fueron 21,8±4,4 para la CdV, 6,6±5,6 para la depresión y 3,0±2,8 para el estigma. Casi el 17% informó de la prevalencia de síntomas de depresión. Tanto el estigma (ß = -0,65, p<0 001), como la depresión (ß = -0,32, p<0 001) se asociaron con puntuaciones más bajas para la CdV, mientras que hubo una relación positiva significativa entre el estigma y la depresión (ß = 0,92, p<0 001). Se obtuvieron resultados similares en los modelos de regresión de Poisson. CONCLUSIONES: El estudio mostró una carga considerable de depresión, estigma y mala CdV entre los participantes del estudio con lepra y FL en Nepal. Se requiere un paquete holístico de atención que aborde el bienestar físico, mental y psicológico de las personas con ETD.

Cercopithifilaria spp. of dogs: little known but prevalent filarioids beneath the skin.

Filarioids of the genus Cercopithifilaria are little studied, yet widespread parasites, that are relatively unique in being one of the very few nematodes transmitted by hard ticks. These filarioids live in the subcutis while microfilariae are found in the dermis. Definitive hosts include domestic dogs as well as a wide range of vertebrates, such as ruminants, non-human primates, murids, marsupials, porcupines, viverrids, bears and lagomorphs. The genus Cercopithifilaria contains three taxa (i.e. C. bainae, C. grassii and a yet undescribed species, namely Cercopithifilaria sp. II) that are known to infect dogs worldwide, with their occurrence overlapping the distribution of the main tick vector, Rhipicephalus sanguineus sensu lato. In recent decades, more attention has focused on these filarioids since they have been associated with clinical signs of infection, such as dermatitis, chronic polyarthritis and cutaneous cysts, and possibly with facilitating infections caused by other tick-borne pathogens. Nevertheless, these parasites remain largely underdiagnosed in clinical practice due to the lack of awareness of veterinary practitioners and to major obstacles to their diagnosis. In this review, we have assessed currently available data on Cercopithifilaria spp. infecting dogs worldwide and discussed the biological, clinical and epidemiological aspects of these filarioids, with the overall aim to gain a better understanding of their potential role in skin diseases.

Real time ultrasound diagnosis of ovarian and pelvic filariasis by filarial dance sign.

Parasitic infestations of the ovary are quite rare with ovary being the least common site of infection in the female genital tract. Filariasis is a parasitic disease caused by filarial nematodes (Wuchereria bancrofti, Brugia malayai, Brugia timori). It causes lymphatic obstruction with resultant edema and increase in the size of the affected organ. We report a case of 24-year-old married female who presented to our radiology department for ultrasound evaluation with the main aim being to look for retained products of conception after the termination of early pregnancy. However on ultrasound examination ovarian filariasis was an incidental diagnosis with the classical twirling movement (filarial dance sign) seen in one of the follicles of the ovary. Ultrasound is the imaging modality of choice for detecting the adult filarial worm/microfilaria in the lymphatic system. Ovarian filariasis is a very rare diagnosis with only a handful of cases being reported in literature with most cases being diagnosed incidentally on histopathological examination of the post operative specimen.

Larvicidal Activities of Allium sativum L. and Zingiber officinale Rosc. Extracts against Filariasis Vectors in Hadiya Zone, Ethiopia.

Mosquitoes present an immense threat to millions of people worldwide and act as vectors for filariasis disease. The objective of the study was to determine the effect of Allium sativum and Zingiber officinale extracts against filariasis vectors. The larvae were collected from the breeding site by using standard procedures for identification and larvicidal activities. Twenty grams (20 g) from each (Allium sativum and Zingiber officinale) were extracted separately by aqueous, ethanol, and methanol solvents. The phytochemical analysis was determined in the crude sample by using standard methods. Then, larvicidal effects were determined by introducing 10 larvae of the vectors to the concentrations of 250 ppm, 500 ppm, and 750 ppm of the crude sample, and data were subjected to probit analysis to determine the LC50 and Chi-squared test to check the significance of the mortality by R software. Anopheles funestus, Anopheles gambiae s.l., Anopheles pharoensis, Culex antennatus, and Culex quinquefasciatus were the filariasis vectors identified during the study period. The presence of phytochemical tests such as anthraquinones, flavonoids, glycosides, phenol, saponin, steroids, tannin, and terpenes was obtained. The larvicidal effects of the selected plant extracts ranged from 0%-100%. The lowest LC50 (53 ppm) was observed for A. sativum methanol test extract against Cx. quinquefasciatus. Ethanol extracts of A. sativum have a significant effect on An. funestus (X2 = 7.5, p = 0.02352) and Cx. quinquefasciatus (X2 = 10.833, p = 0.0.0044), whereas aqueous extracts have a significant effect only on An. gambiae s.l. (X2 = 7.0807, p = 0.029. Ethanol extracts of Z. officinale have a significant effect only on the mortality of An. pharoensis (X2 = 7.0807, p = 0.029), but methanol and aqueous extracts have no significant effect against filariasis vectors. In conclusion, A. sativum have a high toxic effect than Z. officinale extract against filariasis vectors in all type of solvents. So using those plant extracts is the best to reduce the risk of the synthetic chemical on nontarget organisms and the environment, in addition to the control of mosquito-borne diseases, but further studies will be conducted to evaluate the toxicity at different stages of the vectors.

Macrophages show up in style when Th2 lymphocytes organize their homecoming.

Monocytes can differentiate into tissue-resident pleural macrophages, but the mechanisms underlying this process are not yet fully understood. In this issue of Immunity, Finlay et al.1 show that Th2 cytokines promote this differentiation in resistant mice infected with Litomosoides sigmodontis.

Molecular Research on Vector-Borne Diseases of Medical Interest: From Bench to Application 2.0.

Infectious diseases caused by parasites (malaria, leishmaniasis, trypanosomiasis, filariasis…), viruses (chikungunya, dengue, phlebovirus, etc [...].

Molecular and morphometric differentiation of secondary filariasis vector Coquillettidia mosquitoes (Diptera: Culicidae) in Thailand.

Coquillettidia mosquitoes are important nuisance-biting pests and a vector of brugian filariasis in Thailand. However, comprehensive information about these mosquitoes remains unavailable such as molecular and morphometric differences among species. The lack of vector knowledge on Coquillettidia species could affect future disease control. This study aims to investigate differences in molecular variations based on mitochondrial cytochrome oxidase subunit I (COI) gene and wing geometric traits of three Coquillettidia species, namely Cq. crassipes, Cq. nigrosignata, and Cq. ochracea in Thailand. The results of molecular analyses revealed the differences among three Coquillettidia species. The genetic difference measure based on the Kimura two-parameter model among three Coquillettidia species showed low intraspecific distances (0%-3.05%) and large interspecific distances (10.10%-12.41%). The values of intra- and inter-genetic differences of three Coquillettidia species did not overlap which showed the existence of a barcoding gap indicating the efficiency of the identification based on the COI gene. As with molecular analysis, the landmark-based geometric morphometrics approach based on wing shape analysis indicated three distinct species groups which were supported by the high total performance score of cross-validated classification (97.16%). These results provide the first evidence of taxonomic signal based on molecular and wing geometric differences to support species identification and biological variations of Coquillettidia mosquitoes in Thailand for understanding these rare vector mosquitoes in depth and leading to effective further mosquito control.

Wolbachia Ferrochelatase as a potential drug target against filarial infections.

Filarial infections are among the world's most disturbing diseases caused by 3 major parasitic worms; Onchocerca volvulus, Wuchereria bancrofti, and Brugia malayi, affecting more than 500 million people worldwide. Currently used drugs for mass drug administration (MDA) have been met with several challenges including the development of complications in individuals with filaria co-infections and parasitic drug resistance. The filarial endosymbiont, Wolbachia, has emerged as an attractive therapeutic target for filariasis elimination, due to the dependence of the filaria on this endosymbiont for survival. Here, we target an important enzyme in the Wolbachia heme biosynthetic pathway (ferrochelatase), using high-throughput virtual screening and molecular dynamics with MM-PBSA calculations. We identified four drug candidates; Nilotinib, Ledipasvir, 3-benzhydryloxy-8-methyl-8-azabicyclo[3.2.1]octane, and 2-(4-Amino-piperidin-1-yl)-ethanol as potential small molecules inhibitors as they could compete with the enzyme's natural substrate (Protoporphyrin IX) for active pocket binding. This prevents the worm from receiving the heme molecule from Wolbachia for their growth and survival, resulting in their death. This study which involved targeting enzymes in biosynthetic pathways of the parasitic worms' endosymbiont (Wolbachia), has proven to be an alternative therapeutic option leading to the discovery of new drugs, which will help facilitate the elimination of parasitic infections.

A DBHS family member regulates male determination in the filariasis vector Armigeres subalbatus.

The initial signals governing sex determination vary widely among insects. Here we show that Armigeres subalbatus M factor (AsuMf), a male-specific duplication of an autosomal gene of the Drosophila behaviour/human splicing (DBHS) gene family, is the potential primary signal for sex determination in the human filariasis vector mosquito, Ar. subalbatus. Our results show that AsuMf satisfies two fundamental requirements of an M factor: male-specific expression and early embryonic expression. Ablations of AsuMf result in a shift from male- to female-specific splicing of doublesex and fruitless, leading to feminization of males both in morphology and general transcription profile. These data support the conclusion that AsuMf is essential for male development in Ar. subalbatus and reveal a male-determining factor that is derived from duplication and subsequent neofunctionalization of a member of the conserved DBHS family.

Unraveling cross-reactivity of anti-glycan IgG responses in filarial nematode infections.

Parasitic nematodes responsible for filarial diseases cause chronic disablement in humans worldwide. Elimination programs have substantially reduced the rate of infection in certain areas, but limitations of current diagnostics for population surveillance have been pointed out and improved assays are needed to reach the elimination targets. While serological tests detecting antibodies to parasite antigens are convenient tools, those currently available are compromised by the occurrence of antibodies cross-reactive between nematodes, as well as by the presence of residual antibodies in sera years after treatment and clearance of the infection. We recently characterized the N-linked and glycosphingolipid derived glycans of the parasitic nematode Brugia malayi and revealed the presence of various antigenic structures that triggered immunoglobulin G (IgG) responses in infected individuals. To address the specificity of IgG binding to these glycan antigens, we screened microarrays containing Brugia malayi glycans with plasma from uninfected individuals and from individuals infected with Loa loa, Onchocerca volvulus, Mansonella perstans and Wuchereria bancrofti, four closely related filarial nematodes. IgG to a restricted subset of cross-reactive glycans was observed in infection plasmas from all four species. In plasma from Onchocerca volvulus and Mansonella perstans infected individuals, IgG binding to many more glycans was additionally detected, resulting in total IgG responses similar to the ones of Brugia malayi infected individuals. For these infection groups, Brugia malayi, Onchocerca volvulus and Mansonella perstans, we further studied the different IgG subclasses to Brugia malayi glycans. In all three infections, IgG1 and IgG2 appeared to be the major subclasses involved in response to glycan antigens. Interestingly, in Brugia malayi infected individuals, we observed a marked reduction in particular in IgG2 to parasite glycans post-treatment with anthelminthic, suggesting a promising potential for diagnostic applications. Thus, we compared the IgG response to a broad repertoire of Brugia malayi glycans in individuals infected with various filarial nematodes. We identified broadly cross-reactive and more specific glycan targets, extending the currently scarce knowledge of filarial nematode glycosylation and host anti-glycan antibody response. We believe that our initial findings could be further exploited to develop disease-specific diagnostics as part of an integrated approach for filarial disease control.

Bio-efficacy of insecticidal molecule emodin against dengue, filariasis, and malaria vectors.

Emodin, a compound isolated from Aspergillus terreus, was studied using chromatographic and spectroscopic methods and compound purity (96%) was assessed by TLC. Furthermore, high larvicidal activity against Aedes aegypti-AeA (LC50 6.156 and LC90 12.450 mg/L), Culex quinquefasciatus-CuQ (8.216 and 14.816 mg/L), and Anopheles stephensi-AnS larvae (6.895 and 15.24 mg/L) was recorded. The first isolated fraction (emodin) showed higher pupicidal activity against AeA (15.449 and 20.752 mg/L). Most emodin-treated larvae (ETL) showed variations in acetylcholine esterase, α and ß-carboxylesterases, and phosphatase activities in the 4th instar, indicating the intrinsic differences in their biochemical changes. ETL had numerous altered tissues, including muscle, gastric caeca, hindgut, midgut, nerve ganglia, and midgut epithelium. Acute toxicity of emodin on brine shrimp Artemia nauplii (54.0 and 84.5 mg/L) and the zebrafish Danio rerio (less toxicity observed) was recorded. In docking studies, Emodin interacted well with odorant-binding-proteins of AeA, AnS, and CuQ with docking scores of - 8.89, - 6.53, and - 8.09 kcal mol-1, respectively. Therefore, A. terreus is likely to be effective against mosquito larvicides.

T helper 2 cells control monocyte to tissue-resident macrophage differentiation during nematode infection of the pleural cavity.

The recent revolution in tissue-resident macrophage biology has resulted largely from murine studies performed in C57BL/6 mice. Here, using both C57BL/6 and BALB/c mice, we analyze immune cells in the pleural cavity. Unlike C57BL/6 mice, naive tissue-resident large-cavity macrophages (LCMs) of BALB/c mice failed to fully implement the tissue-residency program. Following infection with a pleural-dwelling nematode, these pre-existing differences were accentuated with LCM expansion occurring in C57BL/6, but not in BALB/c mice. While infection drove monocyte recruitment in both strains, only in C57BL/6 mice were monocytes able to efficiently integrate into the resident pool. Monocyte-to-macrophage conversion required both T cells and interleukin-4 receptor alpha (IL-4Rα) signaling. The transition to tissue residency altered macrophage function, and GATA6+ tissue-resident macrophages were required for host resistance to nematode infection. Therefore, during tissue nematode infection, T helper 2 (Th2) cells control the differentiation pathway of resident macrophages, which determines infection outcome.

Filarial infections compromise influenza vaccination efficacy: Lessons from the mouse.

Helminth parasites infect more than a quarter of the human population and inflict significant changes to the immunological status of their hosts. Several human studies report impaired responses to vaccinations in helminth-infected individuals. Analysing the impact of helminth infections on the efficacy of influenza vaccinations in the mouse system helps to elucidate the underlying immunological processes. Concurrent infection with the parasitic nematode Litomosoides sigmodontis reduced the quantity and quality of antibody responses to vaccination against seasonal influenza in BALB/c and C57BL/6 mice. This led to impaired vaccination-induced protection against challenge infections with the human pathogenic 2009 pandemic H1N1 influenza A virus in helminth-infected mice. Impaired responses were also observed if vaccinations were performed after immune-driven or drug-induced clearance of a previous helminth infection. Mechanistically, the suppression was associated with a systemic and sustained expansion of IL-10-producing CD4+CD49b+LAG-3+ type 1 regulatory T cells and partially abrogated by in vivo blockade of the IL-10 receptor. In summary, these findings raise the concern that individuals in helminth-endemic areas may not always benefit from vaccinations, even in the absence of an acute and diagnosable helminth infection.