Background
Methods
Human sample sets
Ethics statement
Banked chimpanzee sera
Antigens for multiplex assay
Comparison of Plasmodium malariae MSP119 sequences from other geographic locations
Antigen coupling and multiplex bead assays
Assessment of coupling efficiency
MSP119 competition assays
MSP119-specific antibody binding and elution
Antibody avidity determinations
Data analysis
Results
MSP119 sequences
Assessment of coupling efficiency
Cut-off determinations
MSP119 multiplex assay specificity
Sample | Assay type | Pf1 MSP119 (MFI-bg) | Pm MSP119 (MFI-bg) | Po MSP119 (MFI-bg) | Pv MSP119 (MFI-bg) | Pf CSP-peptide (MFI-bg) | GST (MFI-bg) |
---|---|---|---|---|---|---|---|
Pan Plasmodium Lot 8 serum | Individual monoplex | 28,537 | 355 | 721 | 23,449 | N/A | N/A |
Multiplex | 28,442 | 351 | 724 | 23,688 | 2281 | 41 | |
P. malariae Lot 2 serum | Individual monoplex | 19 | 10,413 | 6 | 2 | N/A | N/A |
Multiplex | 20 | 10,878 | 6 | 2 | 170 | 11 | |
Mozambique donor 15 | Individual monoplex | 28,088 | 1437 | 16,504 | 260 | N/A | N/A |
Multiplex | 28,242 | 1446 | 17,352 | 272 | 26,039 | 53 | |
Mozambique donor 7 | Individual monoplex | 9396 | 734 | 9566 | 78 | N/A | N/A |
Multiplex | 9484 | 798 | 10,623 | 86 | 22,359 | 11 | |
Mozambique donor 8 | Individual monoplex | 28,034 | 23,220 | 11 | 45 | N/A | N/A |
Multiplex | 28,438 | 23,378 | 14 | 47 | 15,819 | 11 | |
Mozambique elution mix | Individual monoplex | 28,842 | 27,229 | 20,193 | 24,113 | N/A | N/A |
Multiplex | 28,911 | 27,082 | 21,585 | 24,048 | 17,682 | 279 |
Chimpanzee name | Lab. infection species | Pm MSP119 (MFI-bg) | Po MSP119 (MFI-bg) | Pv MSP119 (MFI-bg) | Pf MSP119 (MFI-bg) | Pf CSP-peptide (MFI-bg) | GST (MFI-bg) |
---|---|---|---|---|---|---|---|
Klimatis |
P. malariae
| 23,289 | 1 | 2 | 119 | 14 | 0 |
Duff |
P. vivax
| 41 | 51 | 26,588 | 64 | 156 | 3 |
Alpert |
P. ovale
| 71 | 22,581 | 724 | 25,757 | 4002 | 0 |
Bit |
P. malariae
| 24,223 | 49 | 664 | 5247 | 23,270 | 19 |
Specificity analysis using antigen competition
Assay specificity in low malaria incidence settings
Sample | Competitor added | Pf MSP119 (MFI-bg) | Pm MSP119 (MFI-bg) | Po MSP119 (MFI-bg) | Pv MSP119 (MFI-bg) | Pf CSP (MFI-bg) | GST (MFI-bg) |
---|---|---|---|---|---|---|---|
Haiti 1 | PBS buffer only | 25,260 | 15 | 21 | 9 | 65 | 1 |
GST | 25,473 | 16 | 21 | 11 | 65 | 4 | |
Pf MSP119 |
13
a
| 14 | 21 | 9 | 70 | 3 | |
Pm MSP119 | 25,058 | 6 | 17 | 8 | 63 | 3 | |
Po MSP119 | 25,344 | 12 | 6 | 7 | 62 | 2 | |
Pv MSP119 | 25,181 | 11 | 18 | 4 | 65 | 3 | |
Cambodia 2 | PBS buffer only | 35 | 21 | 15 | 23,836 | 64 | 1 |
GST | 37 | 22 | 17 | 23,623 | 66 | 1 | |
Pf MSP119 | 28 | 24 | 11 | 21,057 | 70 | 1 | |
Pm MSP119 | 40 | 13 | 17 | 23,348 | 61 | 2 | |
Po MSP119 | 41 | 23 | 13 | 23,662 | 67 | 1 | |
Pv MSP119 | 36 | 22 | 14 |
9
| 61 | 2 | |
Cambodia 3 | PBS buffer only | 29,763 | 3177 | 10 | 9 | 2871 | 0 |
GST | 30,461 | 3443 | 12 | 14 | 2909 | 1 | |
Pf MSP119 |
32
| 3428 | 11 | 15 | 2821 | 1 | |
Pm MSP119 | 30,233 |
9
| 14 | 13 | 2817 | 0 | |
Po MSP119 | 30,352 | 3480 | 10 | 12 | 3041 | 1 | |
Pv MSP119 | 30,129 | 3043 | 12 | 4 | 2879 | 2 | |
Cambodia 4 | PBS buffer only | 15 | 6 | 13 | 20,899 | 17 | 0 |
GST | 15 | 7 | 13 | 20,930 | 13 | 1 | |
Pf MSP119 | 9 | 6 | 14 | 15,929 | 14 | 0 | |
Pm MSP119 | 12 | 2 | 12 | 20,382 | 16 | 0 | |
Po MSP119 | 11 | 5 | 2 | 20,177 | 15 | 0 | |
Pv MSP119 | 13 | 6 | 12 |
1
| 13 | 0 | |
Cambodia 9 | PBS buffer only | 1882 | 21 | 17 | 12,439 | 22 | 3 |
GST | 2023 | 23 | 21 | 13,095 | 21 | 4 | |
Pf MSP119 |
31
| 22 | 23 | 9347 | 21 | 4 | |
Pm MSP119 | 1877 | 13 | 23 | 12,075 | 20 | 4 | |
Po MSP119 | 1854 | 24 | 17 | 12,679 | 21 | 2 | |
Pv MSP119 | 1725 | 22 | 21 |
4
| 22 | 3 | |
Cambodia 5 | PBS buffer only | 28,405 | 743 | 39 | 24,051 | 1072 | 800 |
GST | 28,084 | 799 | 44 | 24,307 | 1143 | 911 | |
Pf MSP119 |
50
|
439
b
| 34 | 23,510 | 1160 | 881 | |
Pm MSP119 | 26,098 |
31
| 34 | 23,646 | 1136 | 839 | |
Po MSP119 | 27,871 | 737 | 32 | 23,808 | 1103 | 861 | |
Pv MSP119 | 27,620 | 617 | 33 |
19
| 1090 | 828 |
Assay specificity in a high malaria incidence setting
Sample | Competitor added | Pf MSP119 (MFI-bg) | Pm MSP119 (MFI-bg) | Po MSP119 (MFI-bg) | PvMSP119 (MFI-bg) | PfCSP (MFI-bg) | GST (MFI-bg) |
---|---|---|---|---|---|---|---|
Mozambique 6 | PBS buffer only | 28,163 | 93 | 75 | 83 | 24,603 | 22 |
GST | 28,217 | 79 | 57 | 56 | 24,181 | 21 | |
Pf MSP119 |
45
a
| 76 | 54 | 48 | 24,313 | 27 | |
Pm MSP119 | 28,133 | 16 | 54 | 42 | 24,467 | 25 | |
Po MSP119 | 28,237 | 71 | 32 | 47 | 24,533 | 21 | |
Pv MSP119 | 27,881 | 71 | 57 | 17 | 24,367 | 25 | |
Mozambique 13 | PBS buffer only | 29,635 | 24,263 | 660 | 28,869 | 26,738 | 6 |
GST | 29,480 | 24,168 | 656 | 28,481 | 26,414 | 6 | |
Pf MSP119 |
38
| 24,276 | 594 | 28,799 | 26,792 | 6 | |
Pm MSP119 | 29,729 |
395
| 618 | 29,039 | 26,728 | 6 | |
Po MSP119 | 29,522 | 24,142 |
29
| 28,411 | 26,736 | 7 | |
Pv MSP119 | 29,724 | 24,182 | 637 |
122
| 26,670 | 7 | |
Mozambique 17 | PBS buffer only | 27,423 | 1082 | 23,326 | 87 | 23,363 | 2 |
GST | 27,420 | 1164 | 23,551 | 100 | 23,351 | 5 | |
Pf MSP119 |
25
| 1189 | 23,599 | 104 | 23,481 | 3 | |
Pm MSP119 | 27,280 |
18
| 23,389 | 97 | 23,514 | 2 | |
Po MSP119 | 27,239 | 1157 |
16
| 94 | 23,468 | 4 | |
Pv MSP119 | 27,199 | 1173 | 23,387 | 29 | 23,329 | 4 | |
Mozambique 1 | PBS buffer only | 29,855 | 5009 | 4945 | 27,283 | 22,826 | 10 |
GST | 29,797 | 5191 | 4942 | 27,173 | 22,987 | 9 | |
Pf MSP119 |
66
|
3017
b
| 4998 | 26,901 | 22,818 | 11 | |
Pm MSP119 | 29,636 |
169
| 4841 | 26,949 | 22,820 | 8 | |
Po MSP119 | 29,597 | 4578 |
44
| 26,592 | 22,866 | 9 | |
Pv MSP119 | 29,693 | 4946 | 4703 |
57
| 22,879 | 8 | |
Mozambique 20 | PBS buffer only | 26,789 | 27,032 | 491 | 1227 | 23,870 | 24 |
GST | 26,841 | 26,891 | 536 | 1384 | 24,149 | 11 | |
Pf MSP119 |
98
| 27,258 | 459 | 1301 | 24,083 | 30 | |
Pm MSP119 | 26,668 |
488
c
| 388 | 1084 | 23,921 | 20 | |
Po MSP119 | 26,842 | 27,236 |
29
| 1033 | 24,089 | 26 | |
Pv MSP119 | 26,785 | 27,183 | 352 |
108
| 23,745 | 22 | |
Mozambique 16 | PBS buffer only | 27,518 | 6425 | 17,816 | 24,437 | 21,029 | 25 |
GST | 27,782 | 6588 | 18,263 | 24,430 | 21,019 | 17 | |
Pf MSP119 |
25
|
2040
| 18,892 | 24,275 | 21,320 | 20 | |
Pm MSP119 | 27,399 |
80
| 18,126 | 24,324 | 20,318 | 20 | |
Po MSP119 | 27,866 | 6361 |
113
| 21,301 | 21,114 | 23 | |
Pv MSP119 | 27,805 | 6029 |
232
|
2353
| 20,007 | 22 | |
Mozambique 19 | PBS buffer only | 2677 | 2904 | 353 | 16,473 | 23,808 | 5 |
GST | 2977 | 3230 | 371 | 18,213 | 23,981 | 5 | |
Pf MSP119 |
12
| 3187 | 366 | 17,993 | 24,120 | 4 | |
Pm MSP119 | 2950 |
40
|
151
d
| 19,599 | 23,715 | 5 | |
Po MSP119 | 2931 | 2605 |
40
|
8192
| 24,276 | 5 | |
Pv MSP119 | 2648 | 2246 |
107
|
50
| 24,094 | 4 |
Sample | Competitor added | Pf MSP119 (MFI-bg) | Pm MSP119 (MFI-bg) | Po MSP119 (MFI-bg) | PvMSP119 (MFI-bg) | PfCSP (MFI-bg) | GST (MFI-bg) |
---|---|---|---|---|---|---|---|
Mozambique 3 | PBS buffer only | 24,960 | 13,703 | 11,965 | 21,795 | 23,643 | 4 |
GST | 19,926 |
6961
|
6418
|
12,687
| 23,442 | 2 | |
Pf MSP119 |
40
a
|
237
c
|
53
|
232
| 23,742 | 1 | |
Pm MSP119 |
2211
b
|
17
|
40
|
210
| 23,283 | 2 | |
Po MSP119 |
2487
|
183
|
27
|
227
| 23,919 | 3 | |
Pv MSP119 |
2506
|
232
|
69
|
40
| 23,882 | 1 | |
Mozambique 12 | PBS buffer only | 24,121 | 13,890 | 9743 | 10,178 | 25,839 | 20 |
GST | 22,343 |
6172
|
4284
|
4944
| 25,547 | 10 | |
Pf MSP119 |
62
|
62
|
36
|
175
| 25,874 | 10 | |
Pm MSP119 |
1420
|
22
|
31
|
156
| 25,062 | 6 | |
Po MSP119 |
1488
|
54
|
31
|
172
| 25,492 | 7 | |
Pv MSP119 |
1726
|
75
|
49
|
30
| 25,447 | 8 |
Affinity purification of MSP119 antibodies
Sample | Description | Pf MSP119 (MFI-bg) | Pm MSP119 (MFI-bg) | Po MSP119 (MFI-bg) | Pv MSP119 (MFI-bg) | PfCSP (MFI-bg) | GST (MFI-bg) | Teta (MFI-bg) |
---|---|---|---|---|---|---|---|---|
Mozambique 13 | No treatment | 29,650 | 26,475 | 1445 | 28,371 | 26,857 | 12 | 2424 |
Post incubation with Pv coated beads | 30,363 | 26,631 | 1612 | 15,734 | 28,008 | 13 | 3517 | |
Antibody eluted from Pv coated beads | 4 | 0 | 2 |
1061
b
| 0 | 1 | 2 | |
Mozambique 16 | No treatment | 28,323 | 6713 | 18,227 | 24,238 | 18,909 | 28 | 24,114 |
Post incubation with Pv coated beads | 29,956 | 7588 | 3001 | 15,417 | 22,871 | 34 | 26,239 | |
Antibody eluted from Pv coated beads | 0 | 3 |
229
c
|
2173
| 0 | 0 | 0 | |
Mozambique 15 | No treatment | 28,351 | 1555 | 17,238 | 264 | 25,020 | 7 | 12,797 |
Post incubation with Pf coated beads | 12,216 | 1928 | 20,876 | 328 | 28,102 | 7 | 16,773 | |
Antibody eluted from Pf coated beads |
4267
| 2 | 0 | 34 | 0 | 0 | 0 | |
Mozambique 12 | No treatment | 25,821 | 15,187 | 10,551 | 11,465 | 27,920 | 38 | 25,409 |
Post incubation with Pf coated beads | 3919 | 1213 | 806 | 1538 | 29,536 | 37 | 27,357 | |
Antibody eluted from Pf coated beads | 84 | 28 | 21 | 10 | 0 | 1 | 1 |
Sub-class and avidity studies
Sample | Antibody detected | Description | Pf MSP119 (MFI-bg) | Pm MSP119 (MFI-bg) | Po MSP119 (MFI-bg) | Pv MSP119 (MFI-bg) | PfCSP (MFI-bg) | GST (MFI-bg) | Tet (MFI-bg) |
---|---|---|---|---|---|---|---|---|---|
Mozambique 13 | IgG1 | No treatment | 25,380 | 7236 | 369 | 23,068 | 7081 | 1 | 700 |
IgG2 | No treatment | 1255 | 214 | 36 | 778 | 21,283 | 3 | 17 | |
IgG3 | No treatment | 404 | 441 | 50 | 281 | 7555 | 0 | 10 | |
IgG4 | No treatment | 26 | 4 | 3 | 9 | 0 | 0 | 28 | |
Total IgG | No treatment | 31,255 | 26,542 | 1198 | 30,077 | 28,809 | 12 | 1861 | |
Total IgG | 6 M urea wash | 31,009 | 5724 | 623 | 2297 | 28,005 | 3 | 2253 | |
Total IgG | Avidity indexa |
0.99
|
0.22
|
0.52
|
0.08
|
0.97
|
N/D
|
1.21
| |
Mozambique 16 | IgG1 | No treatment | 2425 | 627 | 89 | 190 | 3722 | 9 | 5100 |
IgG2 | No treatment | 107 | 41 | 6003 | 22,534 | 205 | 4 | 168 | |
IgG3 | No treatment | 30,533 | 3401 | 43 | 55 | 5654 | 2 | 107 | |
IgG4 | No treatment | 52 | 6 | 7 | 7 | 13 | 0 | 1206 | |
Total IgG | No treatment | 30,369 | 59,12 | 16,287 | 23,777 | 20,145 | 35 | 24,367 | |
Total IgG | 6 M Urea wash | 29,850 | 3456 | 1689 | 223 | 7332 | 4 | 24,683 | |
Total IgG | Avidity index |
0.98
|
0.58
|
0.10
|
0.01
|
0.36
|
N/D
|
1.01
| |
Mozambique 15 | IgG1 | No treatment | 14,698 | 416 | 4196 | 89 | 11,752 | 1 | 2348 |
IgG2 | No treatment | 573 | 18 | 58 | 26 | 578 | 4 | 67 | |
IgG3 | No treatment | 30,026 | 2400 | 48 | 64 | 19,941 | 0 | 86 | |
IgG4 | No treatment | 3271 | 9 | 4 | 3 | 281 | 0 | 2934 | |
Total IgG | No treatment | 30,749 | 1652 | 18,046 | 302 | 28,269 | 8 | 14,066 | |
Total IgG | 6 M Urea wash | 30,298 | 1183 | 6032 | 35 | 25,232 | 2 | 13,336 | |
Total IgG | Avidity index |
0.99
|
0.72
|
0.33
|
0.12
|
0.89
|
N/D
|
0.95
| |
Mozambique 12 | IgG1 | No treatment | 269 | 45 | 35 | 57 | 7043 | 2 | 4212 |
IgG2 | No treatment | 28 | 15 | 26 | 15 | 468 | 5 | 188 | |
IgG3 | No treatment | 24,515 | 11,988 | 8263 | 8259 | 22,011 | 3 | 33 | |
IgG4 | No treatment | 6 | 1 | 2 | 3 | 9 | 0 | 177 | |
Total IgG | No treatment | 23,607 | 6741 | 4437 | 4162 | 26,444 | 16 | 21,638 | |
Total IgG | 6 M Urea wash | 719 | 36 | 29 | 61 | 19,765 | 4 | 19,375 | |
Total IgG | Avidity index |
0.03
|
0.01
|
0.01
|
0.01
|
0.75
|
N/D
|
0.90
|