Browsing by Author "Ritirupa Roy"

Now showing 1 - 5 of 5

Apolipoprotein E Is Upregulated in Blood and Circulating Monocytes of Indian Patients With Visceral Leishmaniasis
(John Wiley and Sons Inc, 2024) Gulafsha Kausar; Shashi B. Chauhan; Ritirupa Roy; Shashi Kumar; Christian Engwerda; Susanne Nylen; Rajiv Kumar; Mary E. Wilson; Shyam Sundar
Apolipoprotein E (ApoE) has been associated with several diseases including Parkinson's disease, Alzheimer's and multiple sclerosis. ApoE also has documented immunomodulatory functions. We investigated gene expression in circulating monocytes and in bone marrows of patients with visceral leishmaniasis (VL) living in an endemic area in Bihar, India, and contrasted these with control healthy subjects or other diagnostic bone marrows from individuals in the same region. Samples from VL patients were obtained prior to initiating treatment. Our study revealed significant upregulated expression of the apoE transcript in patients with VL. Furthermore, the levels of ApoE protein were elevated in serum samples of subjects with VL compared with healthy endemic controls. These observations may provide clues regarding the complex interactions between lipid metabolism and immunoregulation of infectious and inflammatory diseases. © 2024 John Wiley & Sons Ltd.
Evaluation of blood based quantitative PCR as a molecular diagnostic tool for post kala-azar dermal leishmaniasis (PKDL)
(Springer Science and Business Media B.V., 2024) Awnish Kumar; Vishal K. Singh; Prasoon Madhukar; Rahul Tiwari; Ritirupa Roy; Rajneesh; Sanjana Mehrotra; Shyam Sundar; Rajiv Kumar
Background: Post kala-azar dermal leishmaniasis (PKDL) is a consequential dermal manifestation of visceral leishmaniasis (VL), serving as a parasite reservoir. The traditional diagnostic approach, which requires an invasive skin biopsy is associated with inherent risks and necessitates skilled healthcare practitioners in sterile settings. There is a critical need for a rapid, less invasive method for Leishmania detection. The main objective of this study was to evaluate and compare the diagnostic efficacy of PCR and qPCR in detecting PKDL, utilizing both skin and blood samples and to assess the utility of blood samples for molecular diagnosis. Methods and results: 73 individuals exhibiting clinical symptoms of PKDL and who had tested positive for rK39 rapid diagnostic test (RDT) were enrolled in this study. For the diagnosis of PKDL, both PCR and real-time quantitative PCR (qPCR), employing SYBR Green and TaqMan assays, were performed on blood and skin matched samples. qPCR results using both TaqMan and SYBR Green assay, indicated higher parasite loads in the skin compared to blood, as evident by the Ct values. Importantly, when blood samples were used for PKDL diagnosis by qPCR, an encouraging sensitivity of 69.35% (TaqMan assay) and 79.36% (SYBR Green) were obtained, compared to 8.2% with conventional PCR. Conclusion: The findings of the study suggest the potential utility of blood for molecular diagnosis by qPCR, offering a less invasive alternative to skin biopsies in field setting for the early detection of parasitaemia in PKDL patients and effective management and control of the disease. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
MicroRNAs-mediated regulation of immune responses in parasitic infection
(Elsevier, 2024) Ritirupa Roy; Prasoon Madhukar; Vishal Kumar Singh; Rahul Tiwari; Awnish Kumar; Rajneesh; Madhukar Rai; Vibhav Gautam; Shyam Sundar; Rajiv Kumar
Leishmaniasis is a group of diseases that predominantly affect impoverished individuals in developing regions. Recent research has highlighted the significant role of microRNAs (miRNAs), small noncoding RNA molecules, in regulating gene expression and contributing to disease pathogenesis in leishmaniasis. Understanding the intricate miRNA-mediated interactions provides valuable insights into the underlying mechanisms of leishmaniasis and facilitates the development of targeted interventions. Moreover, miRNAs demonstrate altered expression levels, and their presence in the bloodstream enables noninvasive detection, making them promising biomarker candidates for diagnosis and prognosis. This chapter focuses on the role of miRNAs in regulating the immune response during leishmania infection, emphasizing their potential as both biomarkers and therapeutic targets. © 2024 Elsevier Inc. All rights reserved.
Phenotypic and functional characteristics of monocyte subsets in the blood and bone marrow of Indian subjects with Visceral Leishmaniasis
(Public Library of Science, 2024) Gulafsha Kausar; Shashi Bhushan Chauhan; Ritirupa Roy; Vimal Verma; Sundaram Pandey; Aziza Niyaz; Jaya Chakravarty; Christian R. Engwerda; Susanne Nylen; Rajiv Kumar; Mary E. Wilson; Shyam Sundar
Visceral leishmaniasis (VL) is a potentially fatal parasitic infection caused by Leishmania donovani in India. L. donovani is an obligate intracellular protozoan residing mostly in macrophages of the reticuloendothelial system throughout chronic infection. Monocytic phagocytes are critical in the pathogenesis of different forms of leishmaniasis. Subsets of monocytes are distinguished by their surface markers into CD14+CD16-classical monocytes, CD14+CD16+ intermediate monocytes, and CD16++CD14low non-classical monocyte subsets. During cutaneous leishmaniasis (CL), intermediate monocyte are reported to be a source of inflammatory cytokines IL-1β and TNF, and they express CCR2 attracting them to sites of inflammatory pathology. We examined monocyte subsets in the blood and bone marrow of patients with VL from an endemic site in Bihar, India, and found these contrasted with the roles of monocytes in CL. During VL, intermediate and non-classical CD16+ monocyte subsets expressed instead a non-inflammatory phenotype with low CCR2, high CX3CR1 and low microbicidal oxidant generation, making them more similar to patrolling monocytes than inflammatory cells. Bone marrow CD16+ monocyte subsets expressed a phenotype that might be more similar to the inflammatory subsets of CL, although our inability to obtain bone marrow from healthy donors in the endemic region hampered this interpretation Overall the data suggest that CD16+ intermediate monocyte subsets in VL patients express a phenotypes that contributes to an immunosuppressed pathologic immune state, but in contrast to CL, these do not mediate localized inflammatory responses. © 2024, Public Library of Science. All rights reserved.
The circulating plasma microRNA signature in human visceral leishmaniasis
(American Society for Microbiology, 2025) Ritirupa Roy; Cinthia L. Hudachek; Shashi Bhushan Chauhan; Shashi Kumar; Awnish Kumar; Bayan Sudan Zhanbolat; Madhukar Rai; Rajiv Kumar; Santhanam Sundar; Mary E. Wilson
Visceral leishmaniasis (VL) is a vector-borne disease caused by the obligate intracellular protozoan Leishmania donovani in India. VL can be complicated by post-kala-azar dermal leishmaniasis (PKDL), a macular or nodular rash that develops in 10%-20% of patients after treatment of VL in India. Patients with PKDL are infectious to sand flies,promoting further transmission of the parasite. MicroRNAs (miRNAs) are 18-25 nt, non-coding RNAs that simultaneously regulate the expression of several or many target transcripts. This study was based on the hypothesis that the host response to L. donovani is modifiedby distinct sets of miRNAs in VL or PKDL and that these might differfrom healthy controls. We investigated this hypothesis using a NanoString panel to profilethe miRNAs expressed in the plasma of patients with VL or PKDL diagnosed at a hospital in Bihar, India. We compared these to plasma microRNAs of healthy control individuals from the same endemic villages. miRNAs hsa-miR-223-3p, hsa-miR-191-5p, hsa-miR-23a-3p, and hsa-1285-5p were significantlyhigher in the plasma samples from patients with VL compared to either PKDL or endemic controls. Prediction programs highlighted potential mRNA targeted by these miRNAs, among which we verifiedthe down-modulation of several transcripts belonging to the NFκB and NLRP3 inflammasomepathways in circulating leukocytes of VL patients. By contrast, miRNA patterns in subjects with PKDL were similar to control subjects, possibly suggesting that the pathogenic immune response during PKDL is primarily localized in the skin. © 2025 American Society for Microbiology. All rights reserved.