C57bl 6j wt mice

Six- to eight-week old male and female C57BL/6J mice (WT) and B6.Cg-Pdcd1^tm1.1Shr/J mice (PD-1^-/-) were purchased from The Jackson Laboratory. An infectious isolate of Borrelia burgdorferi B31 was cultured in Barbour-Stoenner-Kelley II (BSK-II) medium at 37°C to exponential phase. Bacteria were counted using a Petroff-Hauser counting chamber and used at an MOI = 10 for all in vitro experiments. For in vivo infections, mice were injected with 100 μl BSK-II (uninfected controls) or 100 μl BSK-II containing 10⁵B. burgdorferi subcutaneously in the center of the abdomen. Infection of the mice was validated by culturing the ears of infected mice at the time of sacrifice in BSK-II medium and visualization of spirochetes under a dark-field microscope.

Generation of the Tg4-42 mouse model has been published previously [18 (link)]. In brief, the Tg4-42 mouse model utilizes the murine Thy1 promotor to overexpress a genetic construct comprising the human Aβ_4-42 sequence fused to the murine thyrotropin-releasing hormone (TRH) signal peptide, allowing Aβ secretion. Tg4-42 mice were generated and maintained on a C57Bl/6J genetic background. In this study, homozygous Tg4-42 (Tg4-42^hom) and C57Bl/6J mice (WT) (Jackson Laboratories, Bar Harbor, ME, USA) were used. All animals were handled according to the German guidelines for animal care, and all experiments have been approved by the local animal care and use committee (Landesamt für Verbraucherschutz und Lebensmittelsicherheit (LAVES), Lower Saxony). In this study, an equal number of female and male mice were used. Access to food and water was provided ad libitum.

Mice used in this study were housed in the Center for Laboratory Animal Medicine and Care (CLAMC) at the McGovern Medical School, Houston, TX. Wild type C57BL/6J mice (WT) were purchased from The Jackson Laboratory (#000664, Bar Harbor, ME). Mice deficient for the SP-A gene (SP-A^−/−) were obtained from Dr. Carole Mendelson^{64 (link),65 (link)}, and were originally generated in the lab of Dr. Samuel Hawgood, who backcrossed the SP-A^−/− locus to a C57B/6 background^{66 (link)}. To reduce genetic and intestinal microbiome differences in our wild type and SP-A^−/− lines used in the investigations, we crossed our SP-A^−/− line with wild type C57BL/6 mice purchased from the Jackson Laboratory and the resulting heterozygotes from different breeding pairs were backcrossed to regenerate the lines. We repeat the backcross process on a yearly basis and house all lines in the location in our animal facility so they receive the same food, bedding and water. Studies were approved by the Animal Welfare Committee of the University of Texas Health Science Center at House (HSC-AWC-17-028) and thus, all methods were carried out in accordance with relevant guidelines and regulations.

Eight-week-old female C57bl6/J mice (WT) were obtained from the Jackson Laboratories (Bar Harbor, ME). The mice were fed a control non-fat diet (NFD or control WT) or a high-fat diet (HFD) for 8 weeks. In the separate cohort of the HFD group, mice were administered the probiotics (VSL#3) at 1x10⁹ CFU for 8 weeks on alternative days. After 8 weeks of feeding, fecal pellets were collected from each group of mice, and DNA was extracted using the MoBio DNA isolation kit. The V4 region of the 16S genes of bacterial genomes will be amplified using the methods of Tyagi et al. 30 , 31 (link). Amplicons were sequenced on an Illumina MiSeq instrument at the University of British Columbia (Microbiome Insights Inc., Canada). Analysis of the sequencing reads of the samples was performed using the standard methodology for microbiome analysis. Briefly, the raw sequence was processed via QIIME. Further, phylogeny and diversity analyses were done using the QIIME and MOTHUR pipelines.

Seventy-six female C57BL/6J mice (WT; Jackson Laboratory, Ellsworth, ME) and female transgenic mice (TNF^−/−, IL1-α^−/−, and C1q^−/−; TKO) at approximately 8 weeks of age were used. Mice had ad libitum access to food and water, and were housed up to 5 animals per cage. Mice were housed at room temperature (22 ± 1°C) on a 12-h reverse light/dark cycle. All experimental procedures and protocols were approved by the Stanford University Institutional Animal Care and Use committee (IACUC).