Journal:
Article Title: Killing of Streptococcus pneumoniae by capsular polysaccharide-specific polymeric IgA, complement, and phagocytes
doi:
Figure Lengend Snippet: (a) IgA-mediated killing of type 14 S. pneumoniae by differentiated HL-60 cells and baby rabbit complement. Phagocyte/bacteria ratio was 400:1. Tests were run in duplicate; results are shown as the mean ± SEM of 3 experiments. (b) Killing of type 14 S. pneumoniae by human polymorphonuclear leukocytes (PMN) and differentiated HL-60 cells in the presence of 10% baby rabbit complement and 1.2 mg/mL of total IgA (98% IgA, <1% IgG, <2% IgM). Given in Results are means ± SEM of experiments (PMN, n = 4; HL-60 cells, n = 6) with IgA purified from serum of volunteers before and 1 month after immunization with 23-valent pneumococcal vaccine. Levels of type 14–specific IgA were 678 ng/mL before immunization and 2,445 ng/mL after immunization in these pools of purified IgA. *P < 0.0001 for percent kill before immunization vs. 1 month after immunization. (c) The efficacy of molecular forms of IgA on phagocytic killing of type 14 S. pneumoniae. Serial dilutions of purified mIgA and pIgA were tested in the presence of 10% baby rabbit complement for their ability to mediate complement-dependent killing of the organism. Percent kill is given as a function of the concentration of anti–type 14 IgA in purified mIgA and pIgA. Tests were run in duplicate; results are shown as the mean ± SEM of 2 experiments.
Article Snippet: Purified IgA or control IgG were incubated with shaking for 30 minutes at 25°C with 1,000 CFU of log-phase type 14 S. pneumoniae (American Type Culture Collection 6314, Rockville, Maryland, USA) ( 29 – 31 ).
Techniques: Purification, Concentration Assay