Browsing by Author "Jahan, Sadaf"

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    A Critical Review on Human Malaria and Schistosomiasis Vaccines: Current State, Recent Advancements, and Developments
    (MDPI, 2023-04-04) Siddiqui, Arif Jamal; Bhardwaj, Jyoti; Saxena, Juhi; Jahan, Sadaf; Snoussi, Mejdi; Bardakci, Fevzi; Badraoui, Riadh; Adnan, Mohd; Medicine, School of Medicine
    Malaria and schistosomiasis are two major parasitic diseases that remain leading causes of morbidity and mortality worldwide. Co-infections of these two parasites are common in the tropics, where both diseases are endemic. The clinical consequences of schistosomiasis and malaria are determined by a variety of host, parasitic, and environmental variables. Chronic schistosomiasis causes malnutrition and cognitive impairments in children, while malaria can cause fatal acute infections. There are effective drugs available to treat malaria and schistosomiasis. However, the occurrence of allelic polymorphisms and the rapid selection of parasites with genetic mutations can confer reduced susceptibility and lead to the emergence of drug resistance. Moreover, the successful elimination and complete management of these parasites are difficult due to the lack of effective vaccines against Plasmodium and Schistosoma infections. Therefore, it is important to highlight all current vaccine candidates undergoing clinical trials, such as pre-erythrocytic and erythrocytic stage malaria, as well as a next-generation RTS,S-like vaccine, the R21/Matrix-M vaccine, that conferred 77% protection against clinical malaria in a Phase 2b trial. Moreover, this review also discusses the progress and development of schistosomiasis vaccines. Furthermore, significant information is provided through this review on the effectiveness and progress of schistosomiasis vaccines currently under clinical trials, such as Sh28GST, Sm-14, and Sm-p80. Overall, this review provides insights into recent progress in malarial and schistosomiasis vaccines and their developmental approaches.
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    Chemoprophylaxis under sporozoites-lumefantrine (CPS-LMF) immunization induce protective immune responses against Plasmodium yoelii sporozoites infection in mice
    (Springer, 2021) Siddiqui, Arif Jamal; Bhardwaj, Jyoti; Hamadou, Walid Sabri; Goyal, Manish; Ashraf, Syed Amir; Jahan, Sadaf; Jamal, Arshad; Sharma, Pankaj; Sachidanandan, Manojkumar; Badraoui, Riadh; Adnan, Mohd; Medicine, School of Medicine
    Malaria represents one of the major life-threatening diseases that poses a huge socio-economic impact, worldwide. Chemoprophylaxis vaccination using a relatively low number of wild-type infectious sporozoites represents an attractive and effective vaccine strategy against malaria. However, the role of immune responses to pre-erythrocytic versus blood-stage parasites in protection against different antimalarial drugs remains unclear. Here, in the present study, we explored the immune responses against the repetitive inoculation of live Plasmodium yoelii (P. yoelii) sporozoites in an experimental Swiss mouse model under antimalarial drug lumefantrine chemoprophylaxis (CPS-LMF). We monitored the liver stage parasitic load, pro/anti-inflammatory cytokines expression, and erythrocytic stage patency, following repetitive cycles of sporozoites inoculations. It was found that repetitive sporozoites inoculation under CPS-LMF results in delayed blood-stage infection during the fourth sporozoites challenge, while sterile protection was produced in mice following the fifth cycle of sporozoites challenge. Intriguingly, we observed a significant up-regulation of pro-inflammatory cytokines (IFN-γ, TNF-α and IL-12) and iNOS response and down-regulation of anti-inflammatory cytokines (IL-4, IL-10 and TGF-β) in the liver HMNC (hepatic mononuclear cells) and spleen cells after 4th and 5th cycle of sporozoites challenge in the CPS-LMF mice. Meanwhile, we also noticed that the liver stage parasites load under CPS-LMF immunization has gradually reduced after 2nd, 3rd, 4th and 5th sporozoites challenge. Overall, our study suggests that chemoprophylaxis vaccination under LMF drug cover develops strong immune responses and confer superior long-lasting protection against P. yoelii sporozoites. Furthermore, this vaccination strategy can be used to study the protective and stage-specific immunity against new protective antigens.
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    Impact of chemoprophylaxis immunisation under halofantrine (CPS-HF) drug cover in Plasmodium yoelii Swiss mice malaria model
    (Institute of Parasitology, Biology Centre of the Academy of Sciences, 2022-02-03) Siddiqui, Arif Jamal; Bhardwaj, Jyoti; Hamadou, Walid Sabri; Goyal, Manish; Jahan, Sadaf; Ashraf, Syed Amir; Jamal, Arshad; Sharma, Pankaj; Sachidanandan, Manojkumar; Badraoui, Riadh; Snoussi, Mejdi; Adnan, Mohd; Medicine, School of Medicine
    In the present study, we have investigated the role of antimalarial drug halofantrine (HF) in inducing the sterile protection against challenges with sporozoites of the live infectious Plasmodium yoelii (Killick-Kendrick, 1967) in Swiss mice malaria model. We observed that during the first to third sequential sporozoite inoculation cycles, blood-stage patency remains the same in the control and chemoprophylaxis under HF drug cover (CPS-HF) groups. However, a delayed blood-stage infection was observed during the fourth and fifth sporozoite challenges and complete sterile protection was produced following the sixth sporozoite challenge in CPS-HF mice. We also noticed a steady decline in liver stage parasite load after 3th to 6th sporozoite challenge cycle in CPS-HF mice. CPS-HF immunisation results in a significant up-regulation of pro-inflammatory cytokines (IFN-γ, TNF-α, IL-12 and iNOS) and down-regulation of anti-inflammatory cytokines (IL-10 and TGF-β) mRNA expression in hepatic mononuclear cells (HMNC) and spleen cells in the immunised CPS-HF mice (after 6th sporozoite challenge) compared to control. Overall, our study suggests that the repetitive sporozoite inoculation under HF drug treatment develops a strong immune response that confers protection against subsequent challenges with sporozoites of P. yoelii.