Fig. 2: Increased abundance of activated CD11b⁺⁺ neutrophils and dysregulated nasal inflammation in PLHIV on long-term ART.

Nasal mucosal cells and paired peripheral blood samples were collected from HIV-adults (n = 10), PLHIV-ART < 3 months (n = 10) and PLHIV-ART > 1 year (n = 10). Cells were stained with fluorochrome-conjugated antibodies targeting CD45, CD66b, CD14, CD10, CD11b, CD62L and CD63. a UMAP visualisation of 60,000 concatenated CD45⁺ cells from nasal mucosa and peripheral blood, clustered using FlowSOM. Heatmap indicates average expression of surface markers across clusters. Tables display the relative frequencies of each cluster in the blood and nasal compartments across the three study groups. b Proportion of nasal CD66b⁺CD11b⁺⁺ neutrophils across study groups. c Concentration of myeloperoxidase (MPO) in nasal lining fluid measured by ELISA. Box plots show the interquartile range (25th–75th percentiles). The bold horizontal line inside each boxplot indicates the median. Whiskers extend to the smallest and largest values within 1.5× the interquartile range (IQR) from the lower and upper quartiles, respectively. Individual points beyond the whiskers denote outliers. d Scatter plot showing correlation between nasal neutrophil and monocyte abundance. e Scatter plot showing correlation between nasal neutrophil abundance and MPO levels and nasal monocyte abundance and MPO. Error bars show the 95% confidence interval around the fitted mean. f–h Correlation dot plots between nasal cytokines and myeloid cell subsets in HIV-adults (n = 30), PLHIV-ART < 3 months (n = 29) and PLHIV-ART > 1 year (n = 34) groups. Cytokine levels were measured using a multiplex MSD assay. Dot size reflects statistical significance (P < 0.05); colour denotes Spearman’s correlation coefficient (R). Statistical comparisons were assessed using two-sided Wilcoxon rank-sum test (b, c) and two-sided Spearman correlation (d–h); P  <  0.05 was considered significant.