Effects of T spiralis infection on hematopoietic stem and progenitor cell populations. (A-C) BM mononuclear cells (BM MNCs) were harvested from control and T spiralis-infected mice 14 days after infection and labeled with cell surface markers for immunophenotypic analysis of (A) HPC and (C) HSC subpopulations and (B) plated into CFU-C assays. (A) CLP (Lin^lowKit^intSca^intCD127⁺); CMP (Lin^lowKit⁺Sca⁻CD34^int/+CD16/32^int); GMP (Lin^lowKit⁺Sca⁻CD34⁺CD16/32^high); MEP, megakaryocyte-erythroid progenitors (Lin^lowKit⁺Sca⁻CD34⁻CD16/32^low). n = 5 mice per group from 2 to 4 independent experiments. Represented are mean ± standard error (SE). Student t test P values: .013 (CLP), .046 (CMP), .0027 (GMP), and .441 (MEP). Black lines indicate P < .05. (B) CFU-C assay. n = 10 mice/group from 4 independent experiments. Student t test P value: .0125 (black line). (C) Frequency of LT-HSC (Lin^lowKit⁺Sca⁺CD34⁻Flk2⁻), ST-HSC (Lin^lowKit⁺Sca⁺CD34⁺Flk2⁻), and MPP (Lin^lowKit⁺Sca⁺CD34⁺Flk2⁺) in control and 2-week infected mice. Student t test P values: .35 (LT-HSC), .77 (ST-HSC), and .95 (MPP). (D) Cell cycle profile of LT-HSCs harvested from control and day 14-infected mice. No difference was observed in the proportion of cells in the G0, G1, and S/G2/M phases of the cell cycle. Error bars: SE. n = 5 mice/group. The same was observed in 2 additional independent experiments, each with n = 5 mice per group (data not shown). (E-F) 1:1 competitive transplantation of BM MNCs from control or 14-day infected mice (donor) and competitor BM MNCs into irradiated recipients. n = 17 to 18 mice from 2 independent experiments. (E) Peripheral blood reconstitution (mean ± SE), assessed by flow cytometry at 4, 8, 12, 16, and 20 weeks. The differential engraftment of control vs infected BM MNCs was tested using a linear mixed-effect model. The group effect (ie, difference between control and T spiralis) was statistically significant (P < .001); a time effect could not be detected in any of the 2 groups (P = .752). (F) Multilineage potential of the engrafted cells was assessed by measuring the mean proportion of donor-derived B, T, and myeloid cells in the recipients’ peripheral blood at week 20 after transplantation (P = .0721).