_{Altered neutrophil extracellular traps in response to Mycobacterium tuberculosis in persons living with HIV with no previous TB and negative TST and IGRA}

Persons living with HIV (PLWH) have an increased risk for tuberculosis (TB). After prolonged and repeated exposure, some PLWH never develop TB and test persistently negative in tests of immune sensitization tuberculin skin test (TST) and interferon gamma release assays (IGRA) for Mycobacterium tuberculosis ( Mtb) . This group has been identified and defined as HIV+ persistently TB, tuberculin and IGRA negative (HITTIN). To investigate potential innate mechanisms unique to individuals with the HITTIN phenotype we compared their neutrophil Mtb infection response to that of PLWH, with no TB history, but who test persistently IGRA positive, and tuberculin positive (HIT). Neutrophil samples from 17 HITTIN (PMN _HITTIN ) and 11 HIT (PMN _HIT ) were isolated and infected with Mtb H37Rv for 1h and 6h. RNA was extracted and used for RNAseq analysis. At 1h of Mtb infection, PMN _HITTIN displayed 151 significantly upregulated and 40 significantly downregulated differentially expressed genes (DEGs) and PMN _HIT 98 significantly upregulated and 11 significantly downregulated DEGs. At the 6h timepoint, PMN _HITTIN displayed 3106 significantly upregulated and 3548 significantly downregulated DEGs while PMN _HIT had 3816 significantly up- and 3794 significantly downregulated DEGs. There was no significant differential transcriptional response at 1h between infected PMN _HITTIN and PMN _HIT. However, when contrasting the log ₂ FC 6h infection response to Mtb from PMN _HITTIN against PMN _HIT , 2285 genes showed significant differential response between the two groups. Apoptosis and NETosis were key pathways linked to the enrichment of genes in PMN _HITTIN when contrasted to PMN _HIT after 6h infection with Mtb . Fluorescence microscopy revealed relatively lower neutrophil extracellular trap formation and cell loss in PMN _HITTIN compared to PMN _HIT , showing that PMN _HITTIN have a distinct response to Mtb .