Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum

Malaria remains one of the most common human infections worldwide. In endemic areas, malaria is a leading cause of morbidity and mortality and it causes significant socioeconomic burdens to the affected people. Monocytes are part of the immune system to control parasite burden and to protect host...

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Main Author: Xuan, Keh Min
Format: Thesis
Language:English
Published: 2021
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Online Access:http://eprints.usm.my/58217/1/Keh%20Min%20Xuan-24%20pages.pdf
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spelling my-usm-ep.582172023-04-27T07:07:55Z Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum 2021-10 Xuan, Keh Min QL360-599.82 Invertebrates Malaria remains one of the most common human infections worldwide. In endemic areas, malaria is a leading cause of morbidity and mortality and it causes significant socioeconomic burdens to the affected people. Monocytes are part of the immune system to control parasite burden and to protect host against malaria infection. Monocytes play their protective roles against malaria via phagocytosis, cytokine production and antigen presentation. Though monocytes are crucial for clearance of malaria infection, they also have been shown to cause adverse clinical outcomes. The objective of this study was to determine the morphology of P. falciparum, to assess phagocytic capability of infected red blood cells by human monocytes and further measure the cytokine secretions of monocytes following phagocytosis by using ELISA. In this study, monocytes were isolated from whole blood collected from healthy individuals while Plasmodium falciparum (3D7) was cultured under optimal conditions. Phagocytotic activity and cytokine production by the monocytes following malaria infection were assessed in vitro by co-culturing the monocytes and P. falciparum-infected red blood cells for 1 and 2 hours. The present study demonstrated that the monocytes phagocytosed the P. falciparum-infected red blood cells and the phagocytosis index increased with longer incubation time, from 8.2% at 1 hour incubation time to 10.4% (p<0.05) at 2 hours incubation time. Following phagocytosis, the monocytes produced TNF-α, initiating innate immune response to help in the clearance of parasite. The data have shown that monocytes cultured alone expressed the highest level of TNF-α during 0 and 1 hour of incubation, while co-culture of monocytes with P. falciparum-infected red blood cells produced the highest level of TNF-α after 2 hours of incubation. Comparing the trend among monocyte control, parasite control and co-culture, all showed an increase in the level of TNF-α produced in the first hour, but the concentration decreased significantly in the second hour. As a conclusion, these findings suggest that monocytes play an important role in malaria infection by phagocytosing the parasites and producing TNF-α for the removal of parasites, thereby initiating an immune response for malaria eradication. 2021-10 Thesis http://eprints.usm.my/58217/ http://eprints.usm.my/58217/1/Keh%20Min%20Xuan-24%20pages.pdf application/pdf en public masters Universiti Sains Malaysia Pusat Pengajian Sains Kesihatan
institution Universiti Sains Malaysia
collection USM Institutional Repository
language English
topic QL360-599.82 Invertebrates
spellingShingle QL360-599.82 Invertebrates
Xuan, Keh Min
Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum
description Malaria remains one of the most common human infections worldwide. In endemic areas, malaria is a leading cause of morbidity and mortality and it causes significant socioeconomic burdens to the affected people. Monocytes are part of the immune system to control parasite burden and to protect host against malaria infection. Monocytes play their protective roles against malaria via phagocytosis, cytokine production and antigen presentation. Though monocytes are crucial for clearance of malaria infection, they also have been shown to cause adverse clinical outcomes. The objective of this study was to determine the morphology of P. falciparum, to assess phagocytic capability of infected red blood cells by human monocytes and further measure the cytokine secretions of monocytes following phagocytosis by using ELISA. In this study, monocytes were isolated from whole blood collected from healthy individuals while Plasmodium falciparum (3D7) was cultured under optimal conditions. Phagocytotic activity and cytokine production by the monocytes following malaria infection were assessed in vitro by co-culturing the monocytes and P. falciparum-infected red blood cells for 1 and 2 hours. The present study demonstrated that the monocytes phagocytosed the P. falciparum-infected red blood cells and the phagocytosis index increased with longer incubation time, from 8.2% at 1 hour incubation time to 10.4% (p<0.05) at 2 hours incubation time. Following phagocytosis, the monocytes produced TNF-α, initiating innate immune response to help in the clearance of parasite. The data have shown that monocytes cultured alone expressed the highest level of TNF-α during 0 and 1 hour of incubation, while co-culture of monocytes with P. falciparum-infected red blood cells produced the highest level of TNF-α after 2 hours of incubation. Comparing the trend among monocyte control, parasite control and co-culture, all showed an increase in the level of TNF-α produced in the first hour, but the concentration decreased significantly in the second hour. As a conclusion, these findings suggest that monocytes play an important role in malaria infection by phagocytosing the parasites and producing TNF-α for the removal of parasites, thereby initiating an immune response for malaria eradication.
format Thesis
qualification_level Master's degree
author Xuan, Keh Min
author_facet Xuan, Keh Min
author_sort Xuan, Keh Min
title Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum
title_short Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum
title_full Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum
title_fullStr Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum
title_full_unstemmed Assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum
title_sort assessment of phagocytosis and cytokine secretions by monocytes in the presence of plasmodium falciparum
granting_institution Universiti Sains Malaysia
granting_department Pusat Pengajian Sains Kesihatan
publishDate 2021
url http://eprints.usm.my/58217/1/Keh%20Min%20Xuan-24%20pages.pdf
_version_ 1776101213664706560