TABLE 2.

Age dependence of lymphocyte protection from MV-induced CNS disease^a

Genotype	No. sick/total no. (%) at age of MV inoculationb:
	Neonate (1 to 3 days)	Adolescent (11 to 17 days)	Adult (26 to 80 days)
CD46+ RAG2+	13/15 (87) [6.2 ± 0.6 days]	3/6 (50) [9.5 ± 1.4 days]	0/10 (0) [NA]
CD46+ RAG2−	10/11 (91) [7.2 ± 0.5 days]	11/13 (85) [16.0 ± 2.0 days]	10/14 (71) [19.3 ± 2.3 days]

^aNSE-CD46^+/+ mice were backcrossed two generations with RAG-2^−/− mice, and the resulting litters were inoculated at various ages with 3 × 10⁴ PFU of MV-Edmonston. Mice were monitored daily for the onset of CNS disease (tremors, seizures, paralysis, and weight loss). Mice that appeared close to death were sacrificed, and tissues were collected for analysis of genotype, as well as for immunohistochemical analysis of brain tissue. Mice which did not become sick were sacrificed 3 to 4 weeks postinfection. Data shown for NSE-CD46^+/−, RAG-2^+/− (immunocompetent), and NSE-CD46^+/−, RAG-2^−/− (lymphocyte-deficient) mice represent the mean time to disease in mice that became sick. 

^bThe mean age of disease onset ± the standard error of the mean is shown in brackets.