Malaria disease severity and resilience: Plasmodium knowlesi infection of Macaca mulatta and Macaca fascicularis Open Access

Peterson, Mariko (Spring 2020)

Permanent URL: https://etd.library.emory.edu/concern/etds/3t945r824?locale=en
Published

Abstract

Plasmodium knowlesi is an emergent zoonotic malaria parasite that has become the most common cause of malaria in Malaysia. Patients infected with P. knowlesi present across the clinical spectrum, and the accepted paradigm is that the natural monkey host in Southeast Asia, Macaca fascicularis (long-tailed macaques) does not exhibit severe disease, while the experimental host, Macaca mulatta (rhesus macaques, of Indian origin) experiences rapidly rising parasitemia and death if not treated. These striking differences provide a unique opportunity to examine determinants of disease severity, with direct application to understanding human P. knowlesi pathophysiology. Here we utilize M. fascicularis and M. mulatta and take a comparative approach to understand P. knowlesi disease severity and its resolution. A mixed cohort of these two species was infected with P. knowlesi Malayan strain sporozoites and studied longitudinally. Temperature was captured continuously via surgically implanted telemetry devices. As expected, M. fascicularis experienced much lower and controlled parasitemias compared to M. mulatta which required treatment. Recrudescent parasitemic peaks in M. fascicularis did not result in temperatures in the febrile range, suggesting that recrudescent parasitemias may not be clinically important. Yet, M. fascicularis did experience severe anemia, with hemoglobin nadirs as low as 4.8 g/dL and kidney injury. Chronicity and resolution of clinical conditions were achieved naturally in M. fascicularis, and only after subcurative treatment in M. mulatta. Twenty-two tissues were analyzed for the presence of parasites, their adhesion to the vascular endothelium, and pathology. Evidence for infected erythrocyte adhesion was observed in the gut tissues of M. mulatta, including by electron microscopy, while parasite adhesion was not clearly evident in M. fascicularis. Bone marrow, splenic and temperature responses occurred earlier in M. fascicularis infections, suggesting a role for immune response timing in disease resilience to this parasite. These findings contribute to better defining determinants of malarial disease in macaque hosts, understanding P. knowlesi pathophysiology, and improving diagnosis and treatment strategies in clinical settings.

Table of Contents

Table of Contents

Chapter 1: Introduction 

1.1  Back to basics: biology of Plasmodium knowlesi ……………………………………………..1

1.2  A tale of two hosts: disease resilience and severity ……………………………………….......3

1.3  Making the jump: P. knowlesi in humans: history, ecology, and clinical importance …………5

1.4  A sticky situation: a role for sequestration in disease severity …………………………………9 

1.5  The early bird and moderation: a role for host response in disease severity …………………11

1.6  Concluding Remarks ………………………………………………………………………...12

Chapter 2: Plasmodium vivax parasite load is associated with histopathology in Saimiri boliviensis with findings comparable to P. vivax pathogenesis in humans

2.1 Introduction ………………………………………………………………………………….14

2.2 Methods 

            Tissue acquisitions from Saimiri boliviensis infected with P. vivax ………………………..15

            Histopathology, pathology scoring, and parasite quantification …………………………16

            Immunohistochemistry …………………………………………………………………..17

            Statistical Analysis ………………………………………………………………………17

2.3 Results

            Parasite kinetics of P. vivax Brazil VII infection in S. boliviensis ………………………18

Plasmodium vivax Brazil VII infection of S. boliviensis causes lung, liver, and kidney tissue damage …………………………………………………………………………………..18

Figure 2.1 Lung tissue sections with representative micrographs showing 

histopathology …………………………………………………………………………...20

Figure 2.2 Liver tissue sections of splenectomized monkeys with representative micrographs showing histopathology ……………………………………………………21

Figure 2.3 Kidney tissue sections of splenectomized monkeys with representative micrographs showing histopathology ……………………………………………………23

Tissue damage is associated with parasite prevalence in specific organs ……………….24

Figure 2.4 Histopathological and parasitological tissue analysis, in the organs of seven infected S. boliviensis ……………………………………………………………………25

2.4 Discussion …………………………………………………………………………………...28

Chapter 3: Disease resilience and malaria: host resistance and disease severity in Macaca mulatta and M. fascicularis to Plasmodium knowlesi infection

3.1 Introduction ………………………………………………………………………………….33

3.2 Methods 

            Experimental Design and Infections ……………………………………………………..34

            Tissue Acquisition and Histopathology ………………………………………………….37

            Telemetry Data Acquisition ……………………………………………………………...37

            Calculation of Severity Metrics ………………………………………………………….38

            Statistical Analysis ………………………………………………………………………39

3.3 Results 

Parasitemia in P. knowlesi infection of a natural host and an experimental host: kinetics and burden ……………………………………………………………………………….39

Figure 3.1 Parasitemia in Rhesus and Kra monkeys ……………………………………..41

Kra monkeys develop a temperature response faster than rhesus monkeys …………….44

Figure 3.2 Temperature in P. knowlesi Infection ……………………………………….45

Figure 3.3 Temperature Response and Inflammation in P. knowlesi Infection ………….49

Kra monkeys develop and resolve severe anemia ………………………………………..51

Figure 3.4 Hemoglobin, Platelet Count, and Reticulocyte Production Index in P. knowlesi-Infected Macaques ……………………………………………………………………….52

Figure 3.5 Hemoglobin and Platelet Levels in P. knowlesi-Infected Macaques ………..54

Figure 3.6: Reticulocyte Production Index as it Relates to Parasitemia and 

Hemoglobin ……………………………………………………………………………..57

Rhesus macaques and kra monkeys show minimal to moderate histopathological 

changes …………………………………………………………………………………..58

Figure 3.7 Schematic Illustrating Tissue Collection in P. knowlesi-Infected Macaque Necropsies ……………………………………………………………………………….59

Figure 3.8 Splenic changes in macaques with P. knowlesi ………………………………61

Figure 3.9 The Bone Marrow Responds Earlier in Kra Monkeys ………………………64

Figure 3.10 Lung Involvement in P. knowlesi is Similar to Lung Involvement in Malaria Caused by Other Parasites ……………………………………………………………….66

Figure 3.11 Renal Involvement Occurs in Both Macaque Species ……………………...68

Figure 3.13 Hepatic Involvement in P. knowlesi Infection ……………………………..70

Chapter 4: Investigating Plasmodium knowlesi infected red blood cell cytoadhesion and sequestration in macaques        

4.1 Introduction ………………………………………………………………………….81 

4.2 Methods 

            Experimental Design and Infections ……………………………………………..83

                        Tissue analysis and parasite enumeration ………………………………………..84

                        Binding Studies ………………………………………………………………….85

                        RNAseq and Targeted Proteomics Analysis …………………………………….88

                        Statistical Analysis ………………………………………………………………88

            4.3 Results

                        Parasites accumulation in tissues varies in host species and infection status ……88

                        Figure 4.1 Parasite tissue burdens in P. knowlesi infection ……………………..90

Figure 4.2 Parasite accumulation in the kra spleen in acute and chronic 

infection ………………………………………………………………………….91

Figure 4.3 Parasite accumulation in the rhesus tissues in acute infection ………..92  

Figure 4.4 Parasite accumulation in the kra bone marrow in acute and chronic infection ……………………………………………………………………….....95

Figure 4.5 Relative parasite tissue densities in kra and rhesus monkeys in acute and chronic infection …………………………………………………………………96

                        Degree of histopathology is weakly correlated with parasite tissue density …….97

Table 4.1: Fisher exact test for tissue score and parasite burden in rhesus acute infection ………………………………………………………………………….98

Table 4.2: Fisher exact test for tissue score and parasite burden in kra acute infection ………………………………………………………………………….98

Figure 4.6 Tissue score vs. parasite count ………………………………………99

Table 4.3 Linear Hierarchical Linear Regression Analysis …………………….101

SICA protein-expressing RBCs infected with mature parasites clearly sequester in rhesus monkeys ………………………………………………………………...103

Figure 4.7 Light microscopy: SICA protein expression and sequestration in the stomach ………………………………………………………………………...104

Figure 4.8 Light microscopy: SICA protein expression and sequestration in the duodenum ………………………………………………………………………105

Figure 4.9 Light microscopy: SICA protein expression and sequestration in the jejunum …………………………………………………………………………106

Figure 4.10 Light microscopy: SICA protein expression and sequestration in the colon ……………………………………………………………………………107

Table 4.4 Fisher exact test for sequestration and species ………………………108

Figure 4.11 Quantification of SICA[+] and SICA[-] parasite margination in the gastrointestinal tissues ………………………………………………………….110

Consideration of putative iRBC receptors, including Mucosal vascular Addressin Cell Adhesion Molecule 1 (MAdCAM1), which is expressed in the gastrointestinal tract………………………………………………………..……………………112

Figure 4.12 Electron microscopy: SICA protein expression and sequestration in the gut ………………………………………………………………………………113

Figure 4.13 SICAvar expression at necropsy SICA[+]-infected monkeys …….114

Figure 4.14 Soluble markers of endothelial activation …………………………116

Figure 4.15 ICAM1 Expression in the Stomach ……………………………….117

Figure 4.16 ICAM1 Expression in the Duodenum …………………………….118

Figure 4.17 ICAM1 Expression in the Colon …………………………………..119

Figure 4.18 MAdCAM1 Expression in the Stomach …………………………..120

P. knowlesi-infected RBCs do not bind CD36, ICAM, or 

MAdCAM…..…………………………………………………………………..122

Figure 4.19 MAdCAM1 Expression in the Duodenum ………………………..123

Figure 4.20 MadCAM1 Expression in the Colon ………………………………124

Figure 4.21 The Effect of Anticoagulant and Binding Buffer on Binding of Rhesus RBCs to C32 Amelanotic Melanoma Cells …………………………………….125

Figure 4.22 The Effect of Trypsin on Binding of Rhesus RBCs to C32 Amelanotic Melanoma Cells ………………………………………………………………...126

Figure 4.23 The Effect of Hematocrit on Binding of Rhesus RBCs to C32 Amelanotic Melanoma Cells …………………………………………………...127

Figure 4.24 The Effect of BSA on Binding of Rhesus RBCs to C32 Amelanotic Melanoma Cells ……………………………………………….………….…….129

Figure 4.25 The Effect of FBS on Binding of Rhesus RBCs to C32 Amelanotic Melanoma Cells ………………………………………………….………….….130

Figure 4.26 The Effect of Naïve Monkey Serum on Binding of Rhesus RBCs to C32 Amelanotic Melanoma Cells ……………………………………………....131

Figure 4.27 Human RBC Binding to C32 Amelanotic Melanoma Cells …..…..132

Figure 4.28 Plasmodium-infected RBC Binding to Transfected CHO Cells …..133

Figure 4.29 Trypsinized Plasmodium-infected RBC Binding to Transfected CHO Cells ………………………………………….…………………………………134

Figure 4.30 Quantification of Untreated and Trypsinized Plasmodium-infected RBC Binding to Transfected CHO Cells ……………….………………………135

4.4 Discussion ………………………………………………………………………….136

Chapter 5: Conclusion ………………………………………………………………………...147

Chapter 6: Appendix 

6.1 Appendix to Chapter 2: Plasmodium vivax parasite load is associated with histopathology in Saimiri boliviensis with findings comparable to P. vivax pathogenesis in humans …………………………………………………………………………………150

Figure 6.1 Parasitemia kinetics from seven S. boliviensis monkeys infected sequentially with P. vivax iRBCs …………………………………………………………………….150

Table 6.1: Review of experimental demographics and parasite kinetics ……………….152

Table 6.2: Summary of histopathological findings ……………………………………153

Table 6.3: Pairwise histology score comparison ………………………………………155

Table 6.4: Tukey HSD post-hoc pairwise comparison ……….………………………..159

Table 6.5: Fisher exact test …………………………………….………………………160

Table 6.6: Multiple linear regression analysis …………………………………………161

Table 6.7: Spearman’s Rank coefficient test …………………………………………..162

6.2 APPENDIX TO CHAPTER 3: Disease resilience and malaria: host resistance and disease severity in Macaca mulatta and M. fascicularis to Plasmodium knowlesi

Infection ………………………………………………………………………………..163

Table 6.8 Cohort Summary ……………………………………………………………163

Figure 6.2 Experimental Design and Parasitemia for E30 (Pilot acute P. knowlesi infection in rhesus macaques) …………………………………………………………………….168

Figure 6.3 Experimental Design and Parasitemia for E07 (Longitudinal P. knowlesi infection in kra monkeys) ……………….…………………………………………..….169

Figure 6.4 Experimental Design and Parasitemia for E06 (Acute P. knowlesi infection in rhesus macaques) ………………………………………………………………………170

Figure 6.5 Experimental Design and Parasitemia for E33 (Chloroquine treatment in acute P. knowlesi infection in macaques) …………………………………………………….171

Figure 6.6 Experimental Design and Parasitemia for E35 (Chronic P. knowlesi infection in macaques) …………………………………………………………………………...172

Figure 6.7 Area under the curve (AUC) as a measure of cumulative parasitemia in P. knowlesi infection of macaques ……………………………………………….………..173

Figure 6.8 Replication rate of P. knowlesi infection in rhesus macaques ……………..174

Figure 6.9 Replication rate of P. knowlesi infection in rhesus macaques ……….……..175  

Figure 6.10 Telemetry and parasitemia for REd16 ……………………………………176

Figure 6.11 Telemetry and parasitemia for RKy15 …………………………...…..……177

Figure 6.12 Telemetry and parasitemia for 11C131 ………….………………..……….178

Figure 6.13 Telemetry and parasitemia for 11C166 …………………………………...179

Figure 6.14 Telemetry and parasitemia for 12C44 …………………………………….180

Figure 6.15 Telemetry and parasitemia for 12C136 ……………………………………181

            Figure 6.16 Telemetry and parasitemia for 12C53 …………………………………….182

            Figure 6.17 Telemetry and parasitemia for H12C8 ……………………………………183

            Figure 6.18 Telemetry and parasitemia for H12C59 …………………………………..184

            Figure 6.19 Telemetry and parasitemia for RCl15 …………………………………….185

            Figure 6.20 Telemetry and parasitemia for RIh16 ……………………………………..186

            Figure 6.21 Telemetry and parasitemia for RTe16 …………………………………….187

            Figure 6.22 Telemetry and parasitemia for RUf16 …………………………………….188

            Figure 6.23 Parasitemia and select hematological parameters for REd16 …………….189

            Figure 6.24 Parasitemia and select hematological parameters for RKy15 …………….190

            Figure 6.25 Parasitemia and select hematological parameters for 11C131 …………….191

            Figure 6.26 Parasitemia and select hematological parameters for 11C166 ……..……..192

            Figure 6.27 Parasitemia and select hematological parameters for 12C44 …..…………193

            Figure 6.28 Parasitemia and select hematological parameters for 12C53 ……………..194

            Figure 6.29 Parasitemia and select hematological parameters for 12C136 …………….195

            Figure 6.30 Parasitemia and select hematological parameters for H12C8 …………….196

            Figure 6.31 Parasitemia and select hematological parameters for H12C59 ……………197

            Figure 6.32 Parasitemia and select hematological parameters for RCl15 ……………..198

            Figure 6.33 Parasitemia and select hematological parameters for RIh16 ……………..199

            Figure 6.34 Parasitemia and select hematological parameters for RTe16 ……………..200

            Figure 6.35 Parasitemia and select hematological parameters for RUf16 …………..….201

            Figure 6.36 Parasitemia and select hematological parameters for RFz15 ……………..202

            Figure 6.37 Parasitemia and select hematological parameters for RNn9 …………..…..203

            Figure 6.38 Parasitemia and select hematological parameters for 13C90 ……….……..204

            Figure 6.39 Parasitemia and select hematological parameters for 14C3 ……….……...205

            Figure 6.40 Parasitemia and select hematological parameters for 14C15 ……………..206

            Figure 6.41 Parasitemia and select hematological parameters for H13C110 …….…….207

            Figure 6.42 Parasitemia and select hematological parameters for 13_116 …….……….208

            Figure 6.43 Parasitemia and select hematological parameters for 13_136 ……………..209

Figure 6.44 Parasitemia and select hematological parameters for RRz15 ………..…….210

Figure 6.45 Parasitemia and select hematological parameters for H13C101 …………..211

Figure 6.46 Parasitemia and select hematological parameters for H14C17 ……………212

Figure 6.47 Parasitemia and select hematological parameters for 13C33 …………..….213

Figure 6.48 Parasitemia and select hematological parameters for 13C74 ……………...214

Table 6.9 Summary of histopathology scores for P. knowlesi-infected macaques …….215

6.3 Appendix to Chapter 4: Chapter 4: Plasmodium knowlesi sequestration is concomitant with the expression of MAdCAM1 on the endothelium in macaques …..…218

Expanded methods for purified protein binding assay ………………………………….218

Figure 6.49 Plate set up for purified protein binding assay ………….………………….220

Figure 6.50 Humidified chamber, washing, and aspiration technique ……….…………221

Figure 6.51 Binding and staining ……….………………….…………………..………222

Expanded methods for cell binding assay ………………………………………….…..223

Figure 6.52 Plate set up and lawn seeding ……….……………………………..………225

Figure 6.53 Stained slide ……………………………………………………….………226

Figure 6.54 Technique for coverslip disc removal from well plate …………………….228

Table 6.10 Tissue parasite count means …….………………………………………….229

Table 6.11 Relative tissue parasite counts ……………………………..……………….231

Figure 6.55: Sequestration and parasite kinetics ………………………………………233

Figure 6.56 Fraction of vessels displaying margination ………………………………..234

Figure 6.57 Fraction of parasitized vessels …………………………………………….235

Figure 6.58 Fraction of vessels displaying margination normalized to parasitemia …..236

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