TABLE 2.

Stimulation of germinal center reactions and CD4⁺ T-cell activation in PP following colonization of GF C3H/HeN mice with SFB and gram-negative M. morganii

Mouse group	% of PP B lymphocytesa		% of PP CD4+ T cellsa CD45RBlow
	PNA+	Surface IgA+
GF (day 0)	5.4	1.6	33
Colonized with SFB
Day 6 p.i.b	7.9	2.0	40
Day 14 p.i.	13.0	4.7	45
Day 28 p.i.	13.0	6.1	47
Day 50 p.i.	17.0	7.1	61
Day 85 p.i.	9.9	11.8
Day 90 p.i.	5.0	2.2	62
Colonized with M. morganii
Day 18 p.i. (day 131)	13.0	5.5
Day 28 p.i. (day 141)	13.0	6.7	59
Day 63 p.i. (day 175)	12.0	6.6	68
Day 90 p.i. (day 202)	16.0	3.8	65
CNVc adults
Group 1	28.0	8.5	70
Group 2	24.0	8.2	54

^aNumbers are averages for groups of three to five mice. 

^bp.i., postinfection. 

^cCNV, conventionally reared.