TABLE 1.

Relative contributions of CD14 and CD11b/CD18 to the binding of P. gingivalis fimbriae^a

Activation step treatment (37°C)	Binding step treatment (on ice)	Binding (RFU) (mean ± SD)d	% Inhibition by Ab treatment
Medium only	Medium only	1,021 ± 177
Medium only	Fimbriae	11,080 ± 1,123
Medium only	Fimbriae + IgG1 isotype control	10,773 ± 895	2.8
Medium only	Fimbriae + anti-CD14	2316 ± 348b	79.1b
Medium only	Fimbriae + anti-CD11b	10,013 ± 934	9.6
Medium only	Fimbriae + anti-CD11b and anti-CD14	2,198 ± 456b	80.2b
PMA	Fimbriae	33,254 ± 3,453c
PMA	Fimbriae + IgG1 isotype control	31,991 ± 2,369	3.8
PMA	Fimbriae + anti-CD11b	16,072 ± 998b	51.7b
PMA	Fimbriae + anti-CD14	21,149 ± 1,164b	36.4b
PMA	Fimbriae + anti-CD11b and anti-CD14	9,660 ± 652b	80.0b
FMLP	Fimbriae	29,570 ± 3,086c
FMLP	Fimbriae + IgG1 isotype control	26,578 ± 2,023	10.1
FMLP	Fimbriae + anti-CD11b	14,953 ± 741b	49.4b
FMLP	Fimbriae + anti-CD14	18,153 ± 1,021b	38.6b
FMLP	Fimbriae + anti-CD11b and anti-CD14	8,457 ± 630b	71.4b

^aHuman monocytes were pretreated for 10 min at 37°C with or without 0.1 μg/ml PMA or 10⁻⁷ M FMLP (activation step). The cells were immediately washed and incubated with biotinylated fimbriae, in the absence or presence of antibody treatment, for 1 h on ice (binding step). Binding was measured as cell-associated fluorescence (relative fluorescence units [RFU]) after staining with streptavidin-FITC. Background fluorescence was determined using cells treated with medium only throughout the experiment, except for incubation with streptavidin-FITC.

^bStatistically significant (P < 0.05) inhibition of binding due to MAb treatment.

^cStatistically significant (P < 0.05) enhancement of binding compared to the corresponding medium-only-pretreated group.

^dn = 3.