Role of complement and antibodies as opsonins of
in in vitro assays. Uptake of hypermucoviscous K1 (A and D, black bars), K5 (B and E, diagonal bars), and non-HMV K. pneumoniae (C and F, white bars) by African Green monkey (AGM) peripheral blood mononuclear cells (PBMC) (A, B and C) or polymorphonuclear leukocytes (PMNL) (D, E and F) was determined as described. The results are expressed as fold-uptake of opsonized bacteria with normal serum from seropositive (Positive/NS) or seronegative (Negative/NS) donors, or heat-inactivated serum from seropositive (Positive/HI) or seronegative (Negative/HI) donors when compared to PBS opsonized bacteria. The error bars represent standard errors for triplicate samples, and the results shown are representative of three independent experiments. Asterisk indicates significant difference between treatments, p ≤ 0.05; Double asterisk indicates significant difference between treatments, p ≤ 0.001; Equal to indicates similarity between treatments, p > 0.05.