112

a number of regimens, including radiotherapy, have beenadvocated. The remarkable success in this case suggeststhat the epipodophyllotoxin, VP 16-213, may have animportant place in the management of these tumours.

Departments of Hæmatology,Radiotherapy, and Dermatology,University of Cape Town, and

Groote Schuur Hospital,Observatory, Cape.

PETER JACOBSHELEN S. KINGWALTER GORDON.

SPERM INHIBITION OF LYMPHOCYTETRANSFORMATION

SIR,-Levis et all speculated that the stimulation ofhuman lymphocytes by allogeneic spermatozoa was elicitedby HL-A or immune response gene determinants on thespermatozoa. We have also observed occasional stimulationof human lymphocytes by allogeneic spermatozoa, but aninhibitory effect of seminal plasma on P.H.A. stimulation oflymphocytes and the mixed lymphocyte culture (M.L.C.)complicates the matter. However, we have examined theeffects of spermatozoa on lymphocytes in mice where thegenetically defined strains allowed us to determine whetherthe major histocompatibility locus, H-2, and its associatedimmune response determinants,2 la, were responsible.Mouse spermatozoa express H-2 antigens,3,4 but appar-

ently not in a haploid manner, 5,6 and there is a morerecent report that newly described immune-response-genedeterminants, which are thought to provide a stimulatoryeffect on the M.L.C.,7 are also present on sperm. In mice,allogeneic spermatozoa did not stimulate lymphocytes at avariety of ratios (see control columns in accompanyingtable) but had a clearly demonstrable inhibitory effect athigh concentrations on the M.L.C. between H-2 differentstrains when the spermatozoa were from the strain providingthe stimulating, mitomycin-treated lymphocytes. However,spermatozoa from mice congenic (B10.BR) with the strain

1. Levis, W. R., Whalen, J. J., Sherins, R. J. Lancet, Oct. 19, 1974,p. 954.

2. Shreffler, D., David, C., Gotze, D., Klein, J., McDevitt, H.,Sachs, D. Immunogen. 1974, 1, 189.

3. Vojtiskova, M. Nature, 1964, 222, 1293.4. Goldberg, E. H., Aoki, T., Boyse, E. A., Bennett, D. Nature,

1970, 228, 570.5. Erickson, R. P. in Proceedings of International Symposium on

Genetics of Sperm (edited by S. Gluecksohn-Waelsch and R. A.Beatty); p. 191. Edinburgh, 1972.

6. Johnson, M. H., Edidin, M. Transplantation, 1972, 14, 781.7. Fathman, G., Handwerger, B. S., Sachs, D. H. J. exp. Med. 1974,

140, 853.8. McDevitt, H. O. 2nd International Congress of Immunology.

Brighton, England, 1974.

providing inhibitory spermatozoa (C57B1/6J), but sharingthe same H-2 locus and its associated la determinants asthe strain providing responding lymphocytes (CBA/J), werealso inhibitory to the M.L.c. (see table). Thus, in mice,effects of spermatozoa on the M.L.C. are not simply relatedto the major histocompatibility locus and/or associatedimmune-response-gene determinants.

Department of Pediatrics,

Department of Medicine,University of California,

San Francisco,California 94143, U.S.A.

ROBERT P. ERICKSON.

DANIEL P. STITES.

SPONTANEOUS AUTOROSETTES IN MAN

SIR,—Peripheral blood lymphocytes of normal indivi-duals 1-3 and of patients with autoimmune hmmolyticanæmia 4 have been shown to form rosettes spontaneouslywhen mixed with autologous erythrocytes in vitro. Ourresults suggest that autorosette-forming cells (A.R.F.C.) innormal subjects are probably T cells.

Sheep red-cell rosettes or autorosettes were formed usingthe technique of Bach et al. 5, modified according to Panget al. (i.e., glutaraldehyde fixation and methylene-bluestaining), with a ratio of 30 erythrocytes to 1 lymphocytein the cell suspension. Aggregates of 3 or more erythro-cytes per lymphocyte were counted as rosettes. With thismethod the average of sheep red-cell rosette-forming cells(S.R.F.C.) per 100 lymphocytes was 58.0 ± 100 (S.D.) andthe mean incidence of A.R.F.C. was 1-74:0-48 (s.D.) in 19normal subjects. A.R.F.C. had the morphological appearanceof small lymphocytes; autologous serum added to the cellmixture had no effect on the counts obtained; there wasno obvious relationship with sex or age (unpublished data).To test whether or not A.R.F.c. were T cells, two types

of experiments were used:Centrifugation on a ’ Ficoll-Metrizoate ’ gradient of peripheral

blood lymphocytes, after sheep red-cell rosette formation, is a

procedure known to separate T cells.’ A mixture of lymphocytes

1. Sandilands, G., Gray, K., Cooney, A., Browning, J. D., Anderson,J. R. Lancet, 1974, i, 27.

2. Charreire, J., Bach, J. F. ibid. 1974, ii, 299.3. Dewar, A. E., Stuart, A. E., Parker, A. C., Wilson, C. ibid. p. 519.4. Gluckman, E. ibid. 1970, ii, 101.5. Bach, J. F., Judet, C., Arce, S., Dormont, J. Nouv. Presse Med.

1974, 3, 655.6. Pang, G. T. M., Baguley, D. M., Wilson, J. D. J. Immunol. Meth.

1974, 4, 41.7. O’Toole, C., Stejskal, V., Perlmann, P., Karl, M. J. exp. Med.

1974, 139, 457.

EFFECT OF SPERMATOZOA ON THYMIDINE INCORPORATION INTO CBA/J SPLENOCYTES CULTURED WITH CBA/J OR C57B1/6J SPLENOCYTES(c.p.m. ±S.E.M.)