Lymphocytes: Origin, Structure, and Interrelationships n 



immature lymphocytes. Only the development of occasional small granulo- 

 cytes chiefly basophils, from the cell., which resembled immature lymphocytes 



r» o m :;::' TT^Tr evidence of previous ^-^ zs. 



Unfortunate y, Sudan black staining of these remarkable cells was not pos- 

 sible at the time of consultation. P 



The latter pieces of information suggest that the cell which appears to be a 

 ransmonal form (immature lymphocyte) between the lymphomas and , he 

 ymphocyte could be remarkably important in normal or abnormal 1 , 

 topoiesis in general. d 



Data regarding the cells containing tritium labeled thymidine (H'-thymi- 

 dme) which has been incorporated into the DNA of rapidly pro.ifera m 

 cells are now accumulating. Currently, it has been shown thaf circuU W 

 nonsegmented cells of some type are labeled and are thus cells whi 1 t 

 be expected to d,v, de.« It is not possible to be absolutely certain of „ 

 ypes from the figures or the text, but I should expect them to be immature 

 ymphocytes (their description and Fig. ,- e of Reference 6) and 

 vmphocvtes (Type II. Downey) . The Group 5 cells of Bond and asso s' 

 "Inch appeared to be damaged could be basket cells (not identifiable) 

 damaged immature lymphocytes, or even cells comparable to the cells from 

 he blood of leukemic ret.culoendotheliosis illustrated in this chapter (F," 

 -9 through 1-12) . ft should be re-emphasized that the reticular cell that seems 

 almost to lack cytoplasm can be found along with the histiocyte in the blood 

 septicemia and subacute bacterial endocarditis, and I have seen it in the 

 blood in infectious mononucleosis which presented with an initial histiocytic" 

 picture I have not seen mitoses comparable to those shown in Ficres 11 

 nd -12 m nonleukemic blood. I have frequently seen mitoses in et C I 

 lymphocytes in the blood in infectious mononucleosis, and I have occasion 

 s en mitoses in plasmablasts in acquired hemolytic anemia. Mitoses in « " 

 ular lymphocytes and plasmablasts do occur in the blood in the absence of 

 eukemia. I should not be surprised to find a mitosis in an immature ™pho 

 cyte m some of the lymphocytoses of infancy but do not recall having 

 one. That the real unidentifiable basket cell, may be premitotic ceMs 7s a 

 surprise. I should tentatively conclude that the "mobile poo, of p ™ v 

 progenitor cells • consists of cells comparable to those found in the germmll 

 centers f lymph nodes. It is difficult to conceive of the reticular lympCyTes 

 plasmablasts. and immature plasma cells as truly muhipotential J unS 

 most circumstances, but the number of these cells found by Bond a, < a, so 

 cates^ suggest that very probably the label was bound to these ceM t p s 

 surely are capable of division. The reticular cell that seems to lack cm,,, 

 ■s totally acceptable as a muhipotential stem cell. The immature lympt" 

 may be similarly muhipotential and may function as a transitional ormTe 

 tween the lymphocyte and other blast forms. 



