TABLE 1.

IFN-β production by Lpsⁿ and Lps^d macrophages^a

Stimulus	IFN-β in supernatants ofb:
	Lpsn macrophages		Lpsd macrophages
	Sn	BALB/c	Cr	BALB/c/l
None	−	−	−	−
LPS	+	+	−	−
Gram-negative bacteriac	+	+	−	−
Gram-positive bacteriad	−	−	−	−

^aLpsⁿ (Sn and BALB/c) and Lps^d (Cr and BALB/c/l) macrophages (10⁶/ml) were stimulated with 10 μg of LPS/ml or 100 μg of killed bacteria/ml for 8 h. IFN-β in the supernatant was assayed in a bioassay as described in Materials and Methods. 

^b+, 500 to 10,000 U of IFN-β/ml; −, <25 U of IFN-β/ml. 

^cSerovar Typhimurium, E. coli, P. mirabilis, P. aeruginosa, S. enteritidis, and V. cholerae. 

^dS. aureus, S. thermophilus, and L. bulgaricus.