TABLE 1.

Currently defined secondary circuits driving the emergent behavior of an immune response.

Secondary Circuit	Molecular Basis	Site of Interaction	Reference
T-B	LFA-1/ICAM-1 SAP/CD84 “Help” CD40/40L/ Cytokines	LN: T-B Border	(18, 75, 76)
T-T	LFA-1/ICAM-1 IL2, Other cytokines?	LN: T zone, Others?	(15, 84, 96)
CTL-APC or Th-APC (‘re-priming’)	LFA-1/ICAM-1/pMHC/B7	Peripheral Sites?	(97, 98)
T-NK	OX40/OX40L 2B4/CD48	Undefined	(102, 119)
NK-NK	SLAMF…	Undefined	(105)
T-Basophil	Cytokine exchange	Lung, airway proximal	(109)
T-Mast cell	Unknown	Peripheral Sites?	(111).