HOMOGRAFT SENSITIVITY IN HUMAN BEINGS 



273 



and the transfer of delayed sensitivity of the tubercuHn type in 

 human subjects has begun to appear from several laboratories 

 (Freedman, Fisher and Cooke, 1957; Maurer, 1961; Barnett and 



Table I* 

 Some properties of transfer factor 



Biological Biochemical 



TF unaffected by: 



Endows recipient with 25° or 37° — 6 hr. 



specific sensitivity of 



donor 



Sensitivity is systemic Distilled water lysis 



Onset early (hours). 



Freeze-thaw 10 cycles 



Duration long (months- 

 year) 



Minute dosage WBC Deep freeze — 5 months 

 effective 



As little as o-oi ml.->local 



transfer 

 As little as o*i nil.-> 



systemic transfer 

 Capacity for transfer 



depends on degree donor 



sensitivity and dosage 



WBC used 



Negative donors incapable 



Extracts or cell-free super- 

 natants as effective as 

 viable cells 



Does not cross species 

 barrier 



* Reprinted from Lawrence (1960&). 



DNAse 



RNAse 



r DNAse ^ 

 L trypsin J 



Immunological 



Interacts with but is not 

 neutralized by antigen 



White blood ceUs (WBC) 

 desensitized by antigen 



Neg. WBC+antigen^no 

 transfer 



No detectable antibody 

 (AB) in donor WBC 

 extract 



No detectable AB in skin 

 or serum of recipient at 

 time of maximum trans- 

 ferred sensitivity 



Not active sensitization — 

 early onset 



Not passive sensitization — 

 long duration 



Repeated test with antigen 

 may increase intensity 

 and duration of trans- 

 ferred sensitivity — yet is 

 not necessarily its cause 



Sanford, personal communication, 1959; Eisen, personal com- 

 munication, 1961.) Some of the properties of transfer factor, in so 

 far as they are currently known, have been set forth in an earher 



