Fig. 5: Silencing/knocking out the HRH1 gene mimics phenotypes observed with BZT treatment of Mtb-infected THP-1 macrophages. | npj Antimicrobials and Resistance

Fig. 5: Silencing/knocking out the HRH1 gene mimics phenotypes observed with BZT treatment of Mtb-infected THP-1 macrophages.

From: The Parkinson’s drug benztropine possesses histamine receptor 1-dependent host-directed antimicrobial activity against Mycobacterium tuberculosis

Fig. 5

a siRNA-mediated silencing of hrh1 transcription in THP-1 macrophages inhibited intracellular Mtb growth. The addition of BZT (30 µM) did not significantly affect Mtb growth, while the addition of exogenous HIS (10 µM) partially reversed Mtb inhibition caused by hrh1 siRNA. b Western blot of HRH1 protein expression levels in parental and HRH1 K/O cells. Actin is used as a loading control. c HRH1 CRISPR knockout THP-1 macrophage clones (HRH1 K/O) showed reduced intracellular Mtb levels. d Inhibition of Mtb growth in parental THP-macrophages was not significantly altered by BZT (10 µM) in HRH1 K/O. Colocalization of acidic phagosomes and pHrodo-labelled Mtb MC26206 auxotroph expressing GFP; e Heat-killed (HK) or live Mtb parental THP-1 macrophages that were either non-treated (NT) or treated with BZT (30 µM); f Heat-killed (HK) or live Mtb-infected parental THP-1 macrophages and live Mtb-infected HRH1 K/O; and g HK or live Mtb-infected HRH1 K/O that were either not treated (NT) or treated with BZT (30 µM). Data normalised to HK Mtb-infected cells, indicating 100% colocalization. Data represent the mean ± SEM of at least two independent experiments. Statistical significance was determined using unpaired T-test; ****p < 0.0001, ***p < 0.001, **p < 0.005, *p < 0.05; ns non-significant.

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