Int Immunopharmacol
June 2024
Int Immunopharmacol
March 2024
Residing obligatorily as amastigotes within the mammalian macrophages, the parasite Leishmania donovani inflicts the potentially fatal, globally re-emerging disease visceral leishmaniasis (VL) by altering intracellular signaling through kinases and phosphatases. Because the phosphatases that modulate the VL outcome in humans remained unknown, we screened a human phosphatase siRNA-library for anti-leishmanial functions in THP-1, a human macrophage-like cell line. Of the 251 phosphatases, the screen identified the Ca-activated K-channel-associated phosphatase myotubularin-related protein-6 (MTMR6) as the only phosphatase whose silencing reduced parasite load and IL-10 production in human macrophages.
View Article and Find Full Text PDFInt Immunopharmacol
March 2024
The protozoan parasite Leishmania donovani resides within mammalian macrophages and alters its antigen-presenting functions to negatively regulate host-protective T cell responses. This negative regulation of human T cell responses in vitro is attributed to myotubularin-related protein-6 (MTMR6), an ion channel-associated phosphatase. As mouse and human MTMR6 share homology, we studied whether MTMR6 silencing by lentivirally expressed MTMR6shRNA (Lv-MTMR6shRNA) reduced Leishmania growth in macrophages and whether MTMR6 silencing in Leishmania-susceptible BALB/c mice reduced the infection and reinstated host-protective T cell functions.
View Article and Find Full Text PDFLeishmania major and L. donovani cause cutaneous leishmaniasis and visceral leishmaniasis, respectively. Available chemotherapies suffer from toxicity, drug-resistance or high cost of production prompting the need for the discovery of new anti-leishmanials.
View Article and Find Full Text PDFEndocr Metab Immune Disord Drug Targets
May 2024
Systemic Lupus Erythematosus (SLE) or Lupus is a multifactorial autoimmune disease of multiorgan malfunctioning of extremely heterogeneous and unclear etiology that affects multiple organs and physiological systems. Some racial groups and women of childbearing age are more susceptible to SLE pathogenesis. Impressive progress has been made towards a better understanding of different immune components contributing to SLE pathogenesis.
View Article and Find Full Text PDFJ Exp Zool A Ecol Integr Physiol
November 2023
While the seasonal testicular cycle has been well studied regarding internal components, no attention has been given to the testicular capsule (tunica albuginea and tunica serosa). This study elucidated the structure-function modulations of intra-testicular functions by its capsule in the finch red munia (Amandava amandava) during the annual testicular cycle. The birds were studied during breeding (preparatory and breeding) and nonbreeding (regressive and quiescent) reproductive phases using hematoxylin-eosin and acridine orange-ethidium bromide capsule staining, hormonal ELISA (LH and testosterone) and immunohistochemical expression of neuropeptides (GnRH, GnIH) and androgen receptor (AR).
View Article and Find Full Text PDFMultiple pathogen-associated molecular patterns (PAMPs) on a pathogen's surface imply their simultaneous recognition by the host cell membrane-located multiple PAMP-specific Toll-like receptors (TLRs). The TLRs on endosomes recognize internalized pathogen-derived nucleic acids and trigger anti-pathogen immune responses aimed at eliminating the intracellular pathogen. Whether the TLRs influence each other's expression and effector responses-termed TLR interdependency-remains unknown.
View Article and Find Full Text PDFcauses cutaneous leishmaniasis. An antileishmanial vaccine for humans is unavailable. In this study, we report development of two attenuated strains-5ASKH-HP and LV39-HP-by continuous culture (high passage) of the corresponding virulent strains (low passage).
View Article and Find Full Text PDFToll-like receptors (TLRs) recognize the pathogen-associated molecular patterns (PAMPs) and induce host-protective immune response. The role of the profilin-recognizing TLR11/TLR12 in Leishmania infection is unknown. Herein, we report that TLR11/ TLR12 expression increases in virulent L.
View Article and Find Full Text PDFThe effect of two thyroid disrupting pesticides (TDPs) mancozeb (MCZ) and imidacloprid (IMI) on the hypothalamic-pituitary-gonadal/testicular (HPG) axis of a seasonally breeding bird, Amandava amandava has been evaluated. Male birds (n=8/group) were exposed to each of the pesticide (0.25% LD of respective pesticide) as well as to their two equimixture doses (0.
View Article and Find Full Text PDFNon-target organisms, including human and wildlife, are susceptible to deleterious effects of pesticide mixtures in their environment. Present study demonstrated the disruption of the hypothalamic-pituitary-thyroid (HPT) axis in a seasonally breeding wildlife bird Amandava amandava on co-exposure to dithiocarbamate mancozeb/MCZ and neonicotinoid imidacloprid/IMI, at concentrations even lower than respective environmentally realistic exposure level of each of the pesticide. Adult male birds (n=8/group) were exposed individually to 0.
View Article and Find Full Text PDFThe exposure effects of two endocrine disrupting pesticides (EDPs), mancozeb/MCZ and imidacloprid/IMI of the group dithiocarbamate and neonicotinoid respectively, on reproductive behaviors and secondary sexual characters have been studied in a seasonally breeding wildlife bird, red munia (Amandava amandava). Adult male birds were exposed to both the pesticides individually (0.25% LD of each) as well as co-exposed (MIX-I: 0.
View Article and Find Full Text PDFThe parasite Leishmania major counteractively modulates TLR2 and TLR9 expression and their functions. Although TLR1, TLR3, TLR4, and TLR7 are also implicated in Leishmania infection, whether their expression was altered in TLR2 or TLR9 deficiency remained unknown. Therefore, we examined TLR1, TLR3, TLR4 and TLR7 expression in L.
View Article and Find Full Text PDFLeishmania major is a parasite that resides and replicates in macrophages. We previously showed that the parasite enhanced CD40-induced Raf-MEK-ERK signaling but inhibited PI3K-MKK-p38MAPK signaling to proleishmanial effects. As Raf and PI3K have a Ras-binding domain but exert opposite effects on Leishmania infection, we examined whether Ras isoforms had differential roles in Leishmania infection.
View Article and Find Full Text PDFThyroid is an important homeostatic regulator of metabolic activities as well as endocrine mechanisms including those of reproduction. Present investigation elucidated the thyroid disrupting potential of a neonicotinoid imidacloprid and a dithiocarbamate mancozeb in a seasonally breeding wildlife bird, Red Munia (Amandava amandava) who is vulnerable to these two pesticides through diet (seed grains and small insects). Adult male birds were exposed to 0.
View Article and Find Full Text PDFTLRs recognize pathogen-expressed Ags and elicit host-protective immune response. Although TLR2 forms heterodimers with TLR1 or TLR6, recognizing different ligands, differences in the functions of these heterodimers remain unknown. In this study, we report that in Leishmania major-infected macrophages, the expression of TLR1 and TLR2, but not TLR6, increased; TLR2-TLR2 association increased, but TLR2-TLR6 association diminished.
View Article and Find Full Text PDFImmunological homeostasis is often maintained by counteractive functions of two different cell types or two different receptors signaling through different intermediates in the same cell. One of these signaling intermediates is protein kinase C (PKC). Ten differentially regulated PKC isoforms are integral to receptor-triggered responses in different cells.
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