Table 5.

Vaccine-induced T-cell immunity important in protection observed in adoptive-transfer (A-T) studies

Study-Group	A-T Donor Cats		A-T Donor-Recipient Matching			Number of Recipients	FIV Statusc	Protection Rate (%)
	Immune Status	Cell Typea	MLR	MHC-I b	MHC-II b
F2 generation against homologous FIVPet challenge
1A	Vaccinate	T cell	Matched	ND	ND	3	−	3 / 4 (75%)
	Vaccinate	T cell	Matched	ND	ND	1	+
1B	Vaccinate	B cell	Matched	ND	ND	2	+	0 / 2 ( 0% )
1C	Non-vaccinate	PBMC	Unmatched	ND	ND	2	+	0 / 2 ( 0% )
F3/F4 generations against homologous FIVPet challenge
2A	Vaccinate	T cell	Matched	Identical	ND	4	−	4 / 4 (100%)
2B	Vaccinate	CD8+ T cell	Matched	Identical	ND	2	−	2 / 3 (67%)
	Vaccinate	CD8+ T cell	Matched	None	ND	1	+
2C	Vaccinate	CD4+ T cell	Matched	Identicald	ND	2	−	2 / 3 (67%)
	Vaccinate	CD4+ T cell	Matched	Identical	None	1	+
2D	Non-vaccinate	T cell	Matched	ND	ND	1	+	0 / 2 ( 0% )
	Non-vaccinate	PBMC	Unmatched	ND	ND	1	+
2E	None	PBS	None	NA	NA	2	+	0 / 2 ( 0% )
F3/F4 generations against heterologous-subtype-B FIVFC1 challenge
3A	Vaccinate	T cell	Matched	ND	ND	2	−	2 / 4 (50%)
	Vaccinate	T cell	Matched	ND	ND	2	+
3B	Vaccinate	T cell	Unmatched	ND	ND	2	+	0 / 2 ( 0% )
3C	None	PBS	None	NA	NA	4	+	0 / 4 ( 0% )

^aCell type from donor cat adoptively transferred to recipient cat. PBMC were purified by magnetic cell separation systems of Miltenyi Biotec, Inc. (Auburn, CA) in Study 1 and R&D Systems (Minneapolis, MN) in Studies 2 and 3.

^bNot done (ND); not applicable (NA); >37% of the MHC sequences were identical (Identical); none or <10% of the MHC sequences were identical (none).

^cFIV status (+ or −) after challenge with either homologous strain (Studies 1 & 2) or heterologous-subtype-B strain (Study 3).

^dOne pair was not tested but the other pair had >50% of identical MHC-I sequences.