krn-7000 and Escherichia-coli-Infections

Diarrhoeal infections are a major cause of morbidity and mortality with enterotoxigenic Escherichia coli (ETEC) and cholera imposing a significant global burden. There is currently no licensed vaccine for ETEC. Development of new nonliving oral vaccines has proven difficult due to the physicochemical and immunological challenges associated with the oral route. This demands innovative delivery solutions to protect antigens, control their release and build in immune-stimulatory activity. We describe the Single Multiple Pill® (SmPill®) vaccine formulation which combines the benefits of enteric polymer coating to protect against low gastric pH, a dispersed phase to control release and aid the solubility of non-polar components and an optimized combination of adjuvant and antigen to promote mucosal immunity. We demonstrate the effectiveness of this system with whole cell killed E. coli overexpressing colonization factor antigen I (CFA/I), JT-49. Alpha-galactosylceramide was identified as a potent adjuvant within SmPill® that enhanced the immunogenicity of JT-49. The bacteria associated with the dispersed phase were retained within the capsules at gastric pH but released at intestinal pH. Vaccination with an optimized SmPill® formulation promoted CFA/I-specific immunoglobulin A (IgA) responses in the intestinal mucosa in addition to serum IgG and a solubilized adjuvant was indispensable for efficacy.

Topics: Adjuvants, Immunologic; Administration, Oral; Animals; Antibodies, Bacterial; Antigens, Bacterial; Capsules; Diarrhea; Escherichia coli; Escherichia coli Infections; Escherichia coli Vaccines; Female; Fimbriae Proteins; Galactosylceramides; Immunoglobulin A; Immunoglobulin G; Intestines; Mice, Inbred BALB C; Vaccination

Mucosal-associated invariant T (MAIT) cells contribute to protection against certain microorganism infections and play an important role in mucosal immunity. However, the role of MAIT cells remains enigmatic in autoimmune diseases. In this study, we examined the level and function of MAIT cells in patients with rheumatic diseases. MAIT cell, cytokine, and programmed death-1 (PD-1) levels were measured by flow cytometry. Circulating MAIT cell levels were significantly reduced in systemic lupus erythematosus (SLE) and rheumatoid arthritis patients. In particular, this MAIT cell deficiency was more prominent in CD8(+) and double-negative T cell subsets, and significantly correlated with disease activity, such as SLE disease activity index and 28-joint disease activity score. Interestingly, MAIT cell frequency was significantly correlated with NKT cell frequency in SLE patients. IFN-γ production in MAIT cells was impaired in SLE patients, which was due to an intrinsic defect in the Ca(2+)/calcineurin/NFAT1 signaling pathway. In SLE patients, MAIT cells were poorly activated by α-galactosylceramide-stimulated NKT cells, thereby showing the dysfunction between MAIT cells and NKT cells. Notably, an elevated expression of PD-1 in MAIT cells and NKT cells was associated with SLE. In rheumatoid arthritis patients, MAIT cell levels were significantly higher in synovial fluid than in peripheral blood. Our study primarily demonstrates that MAIT cells are numerically and functionally deficient in SLE. In addition, we report a novel finding that this MAIT cell deficiency is associated with NKT cell deficiency and elevated PD-1 expression. These abnormalities possibly contribute to dysregulated mucosal immunity in SLE.

Topics: Active Transport, Cell Nucleus; Adult; Arthritis, Rheumatoid; Autoimmune Diseases; Calcineurin; Calcium Signaling; CD8-Positive T-Lymphocytes; Cytokines; Escherichia coli; Escherichia coli Infections; Female; Galactosylceramides; Humans; Immunity, Mucosal; Interferon-gamma; Lupus Erythematosus, Systemic; Lymphocyte Activation; Lymphocyte Count; Male; Middle Aged; Natural Killer T-Cells; NFATC Transcription Factors; Programmed Cell Death 1 Receptor; Synovial Fluid; T-Lymphocyte Subsets

alpha-Galactosylceramide (alpha-GalCer), which is a specific ligand for CD1d restricted variable-alpha14chain natural killer T cells, has an important role in host defense against a range of microbial infections. We examined whether alpha-GalCer mediates bacterial clearance in a murine urinary tract infection (UTI) model.. The murine UTI model was established by intravesical inoculation of Escherichia coli, Pseudomonas aeruginosa or methicillin resistant Staphylococcus aureus, followed by clamping the distal end of the urethra of C57BL/6 female mice for 4 hours. The antibacterial effect of alpha-GalCer was assessed by comparing the number of cfu/gm kidney tissue 4 days after bacterial inoculation. The prophylactic effect of alpha-GalCer was examined by administrating 3 doses of intraperitoneal alpha-GalCer on alternate days 24 hours before E. coli inoculation. The therapeutic effect of alpha-GalCer was tested by the administration of 2 doses of intraperitoneal alpha-GalCer after bacterial inoculation. To assess cytokine induction by alpha-GalCer serum levels of interleukin-12, interferon-gamma and tumor necrosis factor-alpha were measured by cytometric bead array assay.. When administered before bacterial inoculation, alpha-GalCer showed a strong prophylactic antibacterial effect. alpha-GalCer also showed a marked antibacterial effect on preestablished mice UTI caused by E. coli, P. aeruginosa and methicillin resistant S. aureus. alpha-GalCer induced a significantly higher level of interleukin-12, interferon-gamma and tumor necrosis factor-alpha compared with control glycolipids.. These findings suggest a significant role for alpha-GalCer in regulating antibacterial functions by activating natural killer T cells in the murine UTI model.

Topics: Animals; Cytokines; Disease Models, Animal; Escherichia coli Infections; Female; Galactosylceramides; Killer Cells, Natural; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Pseudomonas Infections; Staphylococcal Infections; Urinary Tract Infections