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. 2013 Jul 11;9(7):e1003487. doi: 10.1371/journal.ppat.1003487

Table 1. Summary of the properties of the SIV Nef mutants lacking anti-tetherin activity.

% BST2 antagonisma BST2 bindingb Nef levelsc % CD4 expressiond % MHC I expressione Relative infectivityf
Nef 100 1 1 37.13 41.40 1
G2A 32.04 0.16 1.02 79.43 93.57 0.81**
5–6 21.43 0.18 1.18 60.76 91.70 0.79**
60–61 24.77 0.70 1.22 71.95 38.73** 0.96**
64–65 25.09 0.54 1.18 71.54 32.44** 0.39
66–67 16.94 0.18 1.07 76.49 31.18** 0.43
68–69 18.36 0.14 1.05 73.93 30.12** 0.27
70–71 28.41 0.28 1.37 75.57 28.71** 0.69**
74–75 10.27 0.71 1.44 83.75 81.31 1.01**
82–83 21.00 1.38 0.44 72.13 22.40 ** 0.51
86–87 27.68 0.47 0.52 42.33** 29.32** 0.79**
88–89 26.91 0.93 1.12 76.28 38.57** 0.76**
106–107 53.63 0.82 1.23 39.61** 47.24** 0.87**
108–109 38.43 1.87 0.82 79.18 89.30 0.76**
110–111 34.26 1.29 0.75 65.06 105.52 0.91**
112–113 26.48 0.35 0.72 62.81 95.97 0.59
116–117 31.34 0.16 0.56 102.68 118.09 0.80**
128–129 35.45 1.11 0.70 51.97 * 86.41 1.33**
130–131 46.05 2.40 0.42 58.22 91.15 1.29**
132–133 40.73 0.79 0.53 64.43 49.67** 0.80**
134–135 25.34 2.58 1.1 113.12 117.88 0.77**
138–139 50.33 0.84 0.97 51.51 * 60.97 0.66**
140–141 45.83 1.38 0.71 60.06 56.69** 0.72**
142–143 23.44 5.10 0.60 95.17 111.06 0.79 **
146–147 32.24 1.56 0.52 105.17 104.02 0.50
152–153 21.50 1.68 0.62 97.31 103.37 1.1**
156–157 23.80 1.46 0.86 110.99 100.27 0.85**
158–159 8.83 0.76 0.60 78.49 87.17 0.70**
160–161 18.60 1.64 0.58 55.78* 93.18 1.05**
164–165 14.13 1.34 0.63 82.35 97.46 0.74**
166–167 13.40 1.40 0.33 83.53 113.26 0.88**
168–169 10.24 2.10 0.33 86.10 88.91 0.54
170–171 16.29 2.61 0.35 54.84* 92.21 0.67**
172–173 12.08 1.34 0.40 81.75 98.37 1.06**
174–175 14.82 0.52 0.2 87.02 93.68 0.72**
176–177 15.34 3.17 0.27 63.49 103.43 0.74**
178–179 12.5 0.17 0.05 101.49 95.05 0.39
180–181 10.97 0.02 0.04 102.40 92.77 0.43
181–182 27.99 0.23 1.11 29.77** 34.02** 0.86**
193–194 14.86 0.22 1.35 49.56** 32.95** 0.80**
195–196 17.45 0.31 1.13 68.21 36.54 ** 0.42
199–200 20.06 0.43 1.22 38.48** 30.86** 0.74**
203–204 13.03 0.74 1.34 68.55 26.83** 0.93**
205–206 11.01 0.94 1.40 75.20 38.95** 0.84**
209–210 13.55 1.40 1.07 52.63* 55.94* 0.66**
a

The percentage of BST-2 antagonism was calculated as the amount of SIV p27 released into the culture supernatant of 293T cells transfected with constructs expressing each of the Nef mutants in the presence of rhesus tetherin relative to the amounts of SIV p27 released in the absence of tetherin.

b

Binding to BST-2 was calculated as the relative band intensity of Nef to the band intensity of tetherin in immunoprecipitated samples.

c

Steady-state levels of Nef protein in cell lysates were estimated by calculating the relative band intensity of each of the Nef mutant proteins compared to wild-type Nef.

d

CD4 levels were calculated as the percentage of CD4 staining (MFI) on cells transfected with each of the indicated Nef-expression constructs relative to CD4 staining (MFI) on cells transfected with an empty vector.

e

MHC class I levels were calculated as the percentage of MHC I staining (MFI) on cells transfected with each of the indicated Nef-expression constructs relative to MHC I staining (MFI) on cells transfected an with empty vector.

f

GHOST X4/R5 cells were infected with SIV Δnef trans-complemented with the indicated wild-type or mutant Nef proteins, and the relative infectivity was calculated as the frequency of infected cells obtained for each of the mutants relative to wild-type Nef at 48-hours post-inoculation.

Nef mutants that retain wild-type levels of CD4-downregulation, MHC class I-downregulation or infectivity enhancement are indicated in bold and italics. For CD4− and MHC class I-downregulation, one asterisk indicates activity within 5 standard deviations of wild-type Nef and two asterisks indicate activity within 3 standard deviations of wild-type Nef. For infectivity enhancement, two asterisks indicate infectivity 5 standard deviations or more over SIV Δnef trans-complemented with empty vector.