JO l' J(\\1. (IF Lr' l' lto,r VOIUIII C N Ulllhe r , Prj/ll ef{ ill Ihe U .S.A. Lymphocytes Bearing Immunoglobulin Determinants In Normal Human Lymph Nodes and in Patients with Lepromatous Leprosyl R. C. Verma, K. Balakrishnan, D. M. Vasudevan and G. P. Immuno globulin receptors havc been dcnlonstratcd on the outer surface of ly m- phocytes by various methods (I, :1 , 5, U, 10. - 17 , 25). Considerable evidence now ex- ists to show that these immunoglobulin dcterminants have much in common with antibody molec ul es and it is postulated (0, 12, 11 ) that th ese may be IgM or IgG typc of receptor s or that thesc may rep- rese nt free li ght chains. The indirect or "sandwich" Ruorescc nt antibody test on livin g cell s was first de- scribed by Moller (H) and later adapt ed by Osunkoya et aZ. (16) to stud y the fate of "s urface-receptor serum globulin" compl ex on Burkitt's lymphoma ce lls . More recently RaIf et aZ. (1 7) used this approach to determine the patt ern of distribution of immunoglobulin determinants on lympho- cytes in various lymphoid organs of normal mice. Similar information is lacking so far in human cases. One of the purposes of this communication is to report the proportion of lymphocytes bearing immunoglobulin determinants in human lymph nodes. The function and role of ce ll s carr ying immuno- globulin determinants is not precisely defin ed. However, antisera against total globulins ar e observed not to react with th ymu s derived lymphocyt es ( 17 ) and th e determinants may thu s put in evidence cells committed to humoral immune re- sponse. Th e level of immunoglobulin s, in particular IgG, h as been observed to be I R ecei ved for publi ca ti on 3 August 1 97 0. 2 R . C. Ve rma, M.B.B. S. Post Gra du ate Fe ll ow, Departme nt of Biochemistry; K. Balakrishn an, M.B.B.S., D.C.P., M.Sc. (Immunol. ), Immunol ogist, Office of the D.C .A.F. M.S ., Dep a rtme nt of Bio- che mi stry; D. M. Vasudevan , M.B.B.S., Demons tr a- tor, Depa rtment of Biochemis tr y; G. P_ Ta lwar, M. Sc., D. Sc., F.LC., Professor and H ea d of the De- pa rtment of Biochemistry. All India Ill stitute of Mecli ca l Sci ences, New Delhi II), J,ndia. 20 a ppr ec iabl y raised ill lepromatous lepro sy ( n. II , 1 8) . It was, thereforc, considcrcd of interest to assess thc proportion of lympho- cy tcs bcaring immunoglobulin determi- nants in lymph nodcs of lepromatous lepro- sy pa ti ent s. !vlATERIALS AND METHODS Fluorescein labe ll ed rabbit antihuman immunoglobulin s. Total immunoglobulins were fractionatcd from pooled normal hu- man sera hy half satur ation with ammoni- um sulfate ( I!I). Habbits were immunized with this immunoglobulin fraction emul- sifi ed with Freund's complete adjuvant. Rabbit antihuman Ig globulins wcre sepa - rated from ra bbit sera by half satur ation with ammonium sulfate a nd conjugat ed with Auor esccin isothio cy anat e (8). The stock solution of Auoresce in labclled rabbit antihuman Ig globulins (Fl-anti-H I g) had 10 gm. prote in per ml. Lymph nodes. Normal lymph nodes were obta in ed from subjccts undergoing surgical intervention for diseases not affecting the immunologic system. These nodes were, in all instanccs, ex amined histologica ll y to e x- clude any gross abnormalit y_ Only those tissues showing an essentially normal histo- lo gic pictur es were included in th e se ri es. Lcpromatous le prosy patient s were clinical- ly proven cases with a hi gh bacteri al ind ex and were lepromin negative. Patient s from Tahirpur Leprosy Sanatorium, Shahadar a, Delhi, and a few from our hospital outpa - tient clinics were chosen as subjects. In guinal or supr atrochl ear lymph nodes were re mo ved for examination. The lymph nodes were collected in cold Eagle's Mini- mum Essential Medium ( MEM ). Lymphocyte suspension and F1-anti-H Ig labeI1in g. Th e lymph nodes were cut into small pieces in fr es h cold MEM within