a, b, Whole-mount immunofluorescence was performed on white adipose of 5- and 26-month-old male mice (with and without 2 weeks of 3TC treatment). a, Loss of lamin B1 (senescence marker) was colocalized with IL-6 (SASP marker). b, pSTAT1 (IFN-I marker) was colocalized with ORF1 (L1 marker). c, Quantification of the experiments in a and b. Four mice and at least 200 cells per animal were scored for each condition. d, Neutral lipids were stained with BODIPY to visualize mature adipocytes in whole-mount preparations, and macrophages were detected by immunofluorescence using the F4/80 antibody. e, The effects of 2 weeks of 3TC treatment on adipogenesis were assessed by measuring mean adipocyte size (left), and by RT–qPCR to determine the expression of key adipogenic genes (right; Acaca, acetyl-CoA carboxylase 1; Cebpa, CCAAT/enhancer-binding protein alpha; Fasn, fatty acid synthase; Srebf1, sterol regulatory element-binding protein 1). Adipocyte size (BODIPY-stained area) was calculated using CellProfiler; aggregated data for 5 mice and 500 total cells are shown. For RT–qPCR data, each point represents one animal; n = 6 mice. f, Expression of the Ucp1 gene (thermogenin) in brown adipose tissue was determined by RT–qPCR and is represented as in e. n = 5 mice. g, Expression of L1 mRNA was determined by RT–qPCR and is represented as in e. n = 8 mice at 5 months; n = 12 mice at 26 months; n = 6 mice at 29 months. Box plots as in Fig. 4. Data are mean ± s.d. *P ≤ 0.05, **P ≤ 0.01, one-way ANOVA with Tukey’s multiple comparisons test (c, e, left, f, g), or unpaired two-sided t-test (e, right). Exact P values can be found in the accompanying Source Data.