Table 2 Comparison of secretion and intracellular levels between Arg8His (I/St) and common TNF-α (A/Sn)

From: A new coding mutation in the Tnf-α leader sequence in tuberculosis-sensitive I/St mice causes higher secretion levels of soluble TNF-α

Outcome variable a Time b Mean±s.e. Two-way ANOVA t-test
   Arg8His Common Coef c P-value P-value
Secretion 72 677.3±73.37 486.2±59.12 3.50±1.24 0.0063 0.051
  48 451.8±44.53 348.9±25.80    0.057
Intracellular level 72 1758±97 1856±125 −21.8±92.6 0.82 0.54
  48 1262±51 1189±42    0.28
Secretion corrected for intracellular differences 72 702.0±63.91 521.8±66.77 1.90±0.74 0.013 0.060
  48 433.7±35.39 361.5±25.23    0.11
Proportion of TNF-α producing cells 72 24.29±2.41 23.04±2.70 0.82±2.60 0.75 0.73
  48 29.40±2.82 29.11±2.51    0.94
Number of TNF-α producing cells 72 48 610±3 183 56 964±7 383 ND ND 0.31
  48 27 953±2 685 33 469±3 313    0.20
  1. aSecretion (pg/ml)=supernatant TNF-α concentration per TNF-α producing cell × average cell number per well (72 h: 52 787 cells; 48 h: 30 711 cells); intracellular level=mean channel of fluorescence (arbitrary fluorescence unit); secretion corrected for intracellular differences (pg/ml)=secretion/ratio (intracellular level/average intracellular level (72 h: 1807 fluorescence units; 48 h: 1226 fluorescence units)). Average cell number and average intracellular level was based on all A/Sn and I/St samples.
  2. bTime post-transfection (h).
  3. cRegression coefficient for predictor protein variant in the model including also predictor post-transfection time point. Value>0 means higher outcome variable for Arg8His.
  4. ND: not determined due to significant Bartlett’s test score indicating unequal variances between protein variants.
  5. Number of wells, that is number of transfections, were at 72 h post-transfection 18 I/St and 18 A/Sn; and at 48 h post-transfection 15 I/St and 14 A/Sn.