Table 1.

Elimination of mixed allogeneic chimerism in stable chimeras by anti-RT7a monoclonal antibody treatment

DayChimerism, %LineageTreatment
No. 1No. 2No. 3
 LEW.7B + LEW.1A BMT 
27 15 15 30 Multilineage  
62 15 15 30 Multilineage  
63     Anti-RT7amAb  
66     Anti-RT7a mAb 
70     Anti-RT7a mAb 
97 Mainly B cells  
105 Mainly B cells  
122     Anti-RT7a mAb 
134 Mainly B cells  
204 Mainly B cells  
223 Mainly B cells  
520 < .5  < .5 Few donor cells left  
DayChimerism, %LineageTreatment
No. 1No. 2No. 3
 LEW.7B + LEW.1A BMT 
27 15 15 30 Multilineage  
62 15 15 30 Multilineage  
63     Anti-RT7amAb  
66     Anti-RT7a mAb 
70     Anti-RT7a mAb 
97 Mainly B cells  
105 Mainly B cells  
122     Anti-RT7a mAb 
134 Mainly B cells  
204 Mainly B cells  
223 Mainly B cells  
520 < .5  < .5 Few donor cells left  

LEW.1A rats (n = 3) were treated with 11 Gy of total body irradiation on day −1 and received 100 × 106 bone marrow cells of LEW.7B and LEW.1A native donors (50% each) on day 0. High doses of anti-RT7a monoclonal antibody (mAb) (Figure4) were injected on days 63, 66, 70, and 122. Leukocyte chimerism was analyzed in peripheral blood samples by flow cytometry after staining with lineage-specific mAbs (Figure 1, indirect staining) and anti-RT7a mAb (direct staining).

BMT indicates bone marrow transplantation; mAb, monoclonal antibody.