using this system , it is demonstrated that not only in t helper cell ( th ) -dependent but also in lipopolysaccharide ( lps ) -dependent ( i.e. , so-called t-independent ) pfc responses , the resting b cells have to receive at least three different signals : ( a ) a major histocompatibility complex ( mhc ) -specific th signal that can be bypassed by lps , ( b ) an antigen signal , and ( c ) a second th signal medicated by mhc- and antigen-unspecific helper factor ( s ) for b cell responses ( bhf ) that can not by bypassed by lps .
C0003320
antigen
C0003316
antigen