Figure 6.

CD8⁺ CTL Response Is Compromised in CD169^−/− Mice

(A) Comparison of percent CD8⁺ T cell population in the spleen of B6 and CD169^−/− mice (n = 4) after i.p. administration of CD8α T cell depleting antibodies.

(B) FVC-infected cells in the spleen of B6 and CD169^−/− mice (n = 4, 8 dpi, 2,500 SFFU s.c.) with and without CD8 T cell depletion for an experiment as in (A).

(C) Experimental design for estimating in vivo CTL activity using a 1:1 ratio of FrMLV Gag peptide pulsed dsRed⁺ and non-pulsed GFP⁺ splenocytes in FVC-infected (r.o., 2,500 SFFU) mice.

(D) Representative FACS plots showing comparative killing of Gag peptide pulsed dsRed⁺ splenocytes in uninfected (n = 5) and infected B6.Fv2^s/s (n = 10) and B6.Fv2^s/sCD169^−/− (n = 5) mice for an experiment as in (C).

(E) The graph in the left panel shows the ratio of non-pulsed to pulsed peptide cells in uninfected and infected mice for the experiment shown in (D) in pLN and spleen. The right panel shows specific CTL killing activity of peptide-pulsed cells after normalization to uninfected mice.

(F) Specific CTL activity determined using in vitro assay at indicated effector-to-target ratios using purified CD8⁺ T cells from spleens of uninfected or infected B6 or CD169^−/− mice (7 dpi, 2,500 SFFU r.o.). 1:1 ratio of peptide pulsed dsRed⁺ and non-pulsed GFP⁺ splenocytes were used as targets and CTL activity monitored as in (D) after culturing cells for 48 hr.

(G–K) 2 × 10⁶ splenocytes from FVC-infected B6.Fv2^s/s (n = 5) and B6.Fv2^s/sCD169^−/− (n = 5) (8 dpi, 2,500 SFFU s.c.) or uninfected mice were cultured in vitro with 6 μM Gag peptide for 15–18 hr. The plots show a comparison of cells that stained positive for indicated markers in the CD8⁺ T cell population.

(L) Experimental design to test the in vivo efficacy of adoptively transferred primed CD8⁺ T cells from B6 or CD169^−/− mice to target FVC-infected cells.

(M) FVC-infected cells in the spleen of CD169^−/− mice for an experiment depicted in (L) (n = 4, 7 dpi, 2,500 SFFU r.o.). CD169^−/− mice that did not receive exogenous CD8⁺ T cells were used as control.

p values derived from non-parametric Mann-Whitney test; mean values denoted by horizontal line, error bars denote SD. See also Figures S4–S6.