Measles Immune Suppression: Lessons from the Macaque Model

doi:10.1371/journal.ppat.1002885

Measles Immune Suppression: Lessons from the Macaque Model

Figure 2

Susceptibility of human or macaque T-lymphocyte subsets to in vitro MV infection.

(A) Human or macaque PBMC were sorted into naive (CD45RA⁺, Tⁿ) or memory (CD45RA⁻, T^M) CD4⁺ or CD8⁺ T-lymphocytes, and infected with MV in vitro. Percentages MV-infected T-lymphocytes were determined 2 d.p.i. by measuring EGFP fluorescence by flow cytometry. CD4⁺ (human and macaque) and CD8⁺ (human only) T^M were significantly more susceptible to MV infection than the corresponding Tⁿ. For macaque CD8⁺ T-lymphocytes the difference was significant in two out of three experiments; (B) Unsorted human and macaque PBMC were infected, MV infection percentages in the different T-lymphocyte subsets were determined 2 d.p.i. by flow cytometry. Both in human and macaque PBMC the CD4⁺ and CD8⁺ T^CM and T^EM were significantly more susceptible to MV infection than the corresponding Tⁿ subpopulations. In addition, CD4⁺ T^EM and, to a lesser extent, CD8⁺ T^EM proved more susceptible to MV infection than T^CM. (C–F) Levels of CD150 expression on the different T-lymphocyte subsets in human and macaque PBMC. (C) PBMC collected from human or macaque donors were stained for memory markers as described in Figure S1, in combination with an IgG1 isotype control or CD150^FITC staining. CD150 expression on the different subsets is shown as geometric mean fluorescence intensity (Gmean FI) ± SD. Both for humans and macaques CD150 expression on CD4⁺ and CD8⁺ T^CM and T^EM was significantly higher than on Tⁿ. Interestingly, in CD4⁺ T-lymphocytes CD150 expression was significantly higher on T^EM than on T^CM, whereas in CD8⁺ T-lymphocytes an inverse pattern was observed. (D–F) An IgG1 isotype control was used to determine the level of background staining, and is shown in combination with the CD150 staining for each subset. **, P<0.01. *, P<0.05. Experiments were performed with sorted cells from 3 macaque and 2 human donors, and unsorted cells from 4 macaque and 5 human donors. Data are shown as means ± standard deviation (SD) of representative donors.

doi: https://doi.org/10.1371/journal.ppat.1002885.g002