TABLE 1.

Effects of preadsorbing with selected cell types on the FIV-neutralizing activity of FC vaccine sera and control infected and naive cat sera

Serum no.	Titer of NAa with indicated cell type
	None	MBM	PBMC	PLB-d3	PLB-d12	CrFK	KB
Vaccinated
727	<16	512	<16	<16	64	512	16
733	<16	512	<16	<16	128	64	<16
737	<16	512	<16	<16	64	32	<16
3607	<16	512	<16	<16	128	512	16
Infectedb
753	256	512	NDc	ND	ND	ND	ND
792	512	512	ND	ND	ND	ND	ND
3573	256	512	ND	ND	ND	ND	ND
3588	512	512	ND	ND	ND	ND	ND
3603	512	512	ND	ND	ND	ND	ND
Uninfected, unvaccinated (6 sera)	<16	<16	ND	ND	ND	ND	ND

^aThe titer is expressed as the reciprocal of the highest serum dilution that gave 50% inhibition of reverse transcriptase production by 10 50% tissue culture infectious doses of FIV-M2 mixed with the corresponding dilution of a pool of 10 normal cat sera and calculated by the Reed and Müench method (28). The experiment was repeated twice, with comparable results. 

^bThese cats were infected with plasma from FIV-M2-infected cats; sera were obtained 1 year later. 

^cND, not done.