TABLE 3.

Reactivity of MAb ISU25-C1 and swine anti-PRRSV hyperimmune sera to synthetic peptides bound to MBS-coated ELISA plates

Peptide	Reactivitya with serum or primary antibody (SN titer, ELISA S/P ratio)b:
	6 (64, 1.053)	8 (128, 1.712)	3 (64, 1.835)	5 (64, 1.677)	19 (<4, <0.4)	ISU19-A1 (<2, 0.441)	ISU25-C1 (8, 0.190)
S1 (epitopes A and B) VLVNANNSSSSHFQSIYNC	1.780 (± 0.045)	0.503 (± 0.011)	0.626 (± 0.006)	0.720 (± 0.013)	0.099 (± 0.008)	0.020 (± 0.001)	−0.014 (± 0.014)
S2 (epitope A removed, epitope B present) SGSGA NNSSSSHFQSIYNC	0.152 (± 0.033)	0.189 (± 0.019)	0.284 (± 0.002)	0.051 (± 0.001)	0.036 (± 0.006)	0.013 (± 0.005)	−0.023 (± 0.000)
S3 (epitopes A and B removed) SGSGANNSSSSGS GSIYNC	0.005 (± 0.021)	0.092 (± 0.002)	0.161 (± 0.014)	0.019 (± 0.014)	0.020 (± 0.011)	0.017 (± 0.009)	−0.054 (± 0.399)
S4 (mimotope B) SHITSYHPAYFWC	−0.004 (± 0.014)	−0.185 (± 0.001)	−0.161 (± 0.001)	−0.09 (± 0.003)	−0.100 (± 0.001)	0.037 (± 0.002)	1.811 (± 0.014)
R4N (mimotope A) ALVNIPISNNLAC	1.784 (± 0.022)	0.599 (± 0.004)	1.061 (± 0.003)	1.205 (± 0.018)	0.211 (± 0.002)	0.041 (± 0.006)	−0.04 (± 0.031)
R1N (epitope A) VLVNSNNSSSSAC	1.679 (± 0.085)	0.653 (± 0.005)	0.753 (± 0.016)	0.716 (± 0.011)	0.177 (± 0.001)	0.094 (± 0.058)	−0.001 (± 0.006)
Δ4R1N (epitope A removed) SGSGSNNSSSSAC	−0.010 (± 0.021)	0.123 (± 0.016)	0.174 (± 0.001)	0.010 (± 0.006)	−0.033 (± 0.018)	−0.007 (± 0.008)	−0.031 (± 0.002)

^aResults are expressed as corrected OD at 405 nm (OD for selected phage − OD for unselected phage library) (± standard deviation).

^bSN titer was determined against the PRRSV Iowa strain. ELISA S/P ratio was determined as described in Materials and Methods. Sera 3, 5, 6, and 8 are from PRRSV-hyperimmunized pigs, serum 19 is a negative control (see Materials and Methods), ISU25-C1 and ISU19-A1 are anti-PRRSV neutralizing and nonneutralizing MAbs, respectively.