Tissue Antigens (1984) 24, 320-322

Short communication

HLA-DR phenotypes and blood levels of T cell subsets CALOGERO CARUSO, DOMENICO LIO, PATRIZIA PALMERI and ENRICO CILLARI

Servizio di Immunologia Tissutale, Istituto di Patologia generale dell’Universita di Palermo, Italy

Blood mononuclear cell and T cell subsets values were analyzed in 53 Sicilian indi- viduals according to HLA-DR phenotypes. The results demonstrate that DR1-pos- itive subjects show a significant increase of blood T cell subsets whereas DR3-pos- itive subjects show a non-significant decrease of these values. These results suggest that gene(s) associated with HLA-DR could be one of the factors which affect blood levels of T cell subsets.

Received for publication 16 May, revised, accepted 16 August 1984

Several immunological diseases, in which may occur alteration of T cell subsets with im- munoregulatory function (Fauci 1980, Rein- herz & Schlossman 1980, 1981, Moretta et al. 1981), have been shown to be associated with the alleles of HLA-DR locus, particularly with the DR3 antigen (Moller 1983). For in- stance, Lawley et al. (1981) studied 11 pa- tients affected by dermatitis herpetiformis (a DR3 associated disease), 17 randomly se- lected controls and 9 normal subjects B8-DR3 positive. The authors demonstrated that HLA-B8-DR3 positive controls as well as the patients showed a decrease in the number of lymphocytes and of T cell subset bearing Fc receptors for IgG when compared to ran- domly selected controls. They suggested that the decrease of this immunoregulatory subset might be in connection with the observation that B8 and/or DR3 positive subjects are prone to develop immunological disorders. We have studied the blood values of T cell subsets in 53 randomly selected healthy Si-

cilians typed for HLA antigens to evaluate whether T cell subsets values are associated with DR3 phenotypes.

Material and methods

Lymphocytes with receptor for sheep red blood cells (TJ, and T cells with receptors for IgG (TF) or IgM (TM), were prepared and identified as previously described (Cillari et al. 1982, 1983). The identification of TG or TM cells was confirmed by analysis of the paranu- clear or dotted acid-alpha-naphtyl-acetate es- terase activity (Ferrarini et al. 1980).

Results and discussion

Table 1 shows that DR3-positive subjects have the lowest absolute values of blood total mononuclear cells (MNC) and T cell subsets, as previously reported by Lawley et al. (1981).

T CELL SUBSETS AND DR PHENOTYPES 321

Table 1. Blood MNC and T cell subsets percentage (%) and absolute (lmm’) values in 53 Sicilian individuals analyzed according to DR phenotypes‘,’.

Phenotype3 No. MNC T, T G Thl subjects (/mm3) (/mm3) % (/mm’) % (/mm3) %

All the subjects

53 218.5 (676) 1473(569) 66 (9) 207( 119) 651(306)

DR1 DR2 DR3 DR4 DRS DRw6 DR7

10 8

10 10 22 19 13

2838 (883) 2342( 1024) 1926 (368) 2255 (621) 2001 (596) 2170 (650) 2249 (675)

1912(702) 67 (8) 1630(841) 68 (8) 1301(349) 66(10) 1472(512) 65 (7) 1367(501) 65 (9) 1503(567) 68(10) 1515(633) 65(13)

309( 112) 160 (94) 157 (83) 212 (96) 181 (84) 230( 102) 223(165)

810(323) 626(312) 534(307) 655(297) 591(339) 643( 28 1) 796(405)

43(11)

40 (8)

41 (9)

41 (7)

45(12) 42(16)

43( 11)

46( 11)

DR1-negative 43 2030 (5291” 1376(486)4 - - 185(110)4 - - 578(238) - -

Fifty-three unrelated Sicilian volunteers (18 females and 35 males, mean age 30f7). Several subjects were bled more than twice on different days and the results of the different assays were pooled. No significant difference was observed using age and sex as parameters. Data are expressed as the mean f standard deviation (between brackets). The means were compared among groups of subjects carrying or not carrying the various D R antigens employing Student’s t-test. The applicability of the t-test was verified by F test and graphic inspections of the frequency distributions that were closed to theoretical normal distribution curves. Obtained probability values were corrected (Pc) by multiplying for the number of D R specifities tested (DRl-w9 + blank). In this random population there were no DR8 or Dnv9 positive subjects. Typing for HLA-DR antigens had been performed previously with the use of the two-colour fluorescence test (van Rood et al. 1976). HLA frequencies of this sample of Sicilian population were not significantly different from the published ones (Salerno et al. 1981, Caruso et al. 1983). Statistically significant differences (Pc<0.05) between DR1-positive and DR1-negative subjects.

The decrease affects all the subsets as shown by the fact that the percentage values are indifferent. Comparing the absolute val- ues of the subset and MNC of DR3-positive subjects with those of DR3-negative ones, no significant differences are observed. Results reported in Table 1 demonstrated then that DR1-positive subjects show the highest abso- lute values of blood total MNC and T cell sub- sets. Also, in this case, percentage values are indifferent. The differences among the abso- lute values of MNC and T subsets of DR1- positive and DR1-negative subjects are signi- ficant by Student’s t-test (Pc<0.05; as regards

T,, P value is not significant after correction). The increase of the total number of blood MNC is due to the increase of T cells since no significant variations in B cells and monocytes are observed between DR1-positive and DR1-negative subjects (data not shown). Since the values of MNC, T cell subset, B cell and monocytes are not independent the pos- sibility must be considered that the number of comparisons might be 6 times 10. Thus, these results, not significant anymore, might need confirmation in a larger group of subjects.

However, present and previous results (Lawley et al. 1981) strongly suggest that

322 CARUSO ET AL.

gene(s) associated with HLA-DR could be one of the factors which affect blood levels of T cell subsets. In this regard it has to be re- membered that in mice a number of variations in physiological traits, including the ratios of the lymphocyte subpopulations, have been found to be associated with the major histo- compatibility complex (Ivanyi 1978).

At the moment there are no explanations for these findings. Lawley et al. (1981) have suggested that the alterations in the number of blood T, cell observed in DR3-positive subjects may be due to a defect in expression of Fc receptors, although they did observe a decrease of lymphocytes too. However, in our study, DR1 antigen is linked with a pattern of T cell subsets which is just the contrary of that shown by subsets of DR3-positive subjects. The fact that no immunological spontaneous disorder has been shown to be associated with DRl antigen (Moller 1983) is intriguing.

Acknowledgments

We would like to thank Dr. RenC de Vries and Prof. Alfred0 Salerno for helpful suggestions and criticism. This work was supported by a grant of Minister0 della Pubblica Istruzione (40%, 1982 and 1983). The excellent technical assistance of Carlo Muratore and Antonino Ricotta are appreciated.

References Caruso, C., Oliva, L., Palmeri, P. & Cottone, M.

(1983) B-cell alloantigens in Sicilian patients with Crohn’s disease. Tissue Antigens 21, 17s172.

Cillari, E., Lio, D., Bellina, L., Caruso, C., Brai, M. & Natoli, D. (1982) Lymphocyte subsets in hereditary angioedema. Ann Sclavo 24,666-675.

Cillari, E. , Di Gesu, G . , Palmeri, S . , Lio, D., Sa- lerno, A., Li Voti, P. & La Via, M. F. (1983) Double-rosetting technique for the detection of Fcy receptor-positive T lymphocytes. Diagnostic Immunology 1 , 8 M 6 .

Fauci, A. S. (1980) Immunoregulation in autoim- munity. J Allergy Clin lmmunol66, 517-530.

Ferrarini, M., Cadoni, A , , Franzi, A. T., Ghi- gliotti, C. , Leprini, A , , Zicca, A. & Grossi, C. E. (1980) Ultrastructure and cytochemistry between the cells of the third population and T, lympho- cyte. Eur J lmmunol10, 562-570.

Ivinyi, P. (1978) Some aspects of the H-2 system, the major histocompatibility system in the mouse. Proc R Soc Lond (B) 202, 117-1.58.

Lawley, T. J . , Hall, R. P., Fauci, A. S. , Katz, S. I., Hamburger, M. I. & Frank, M. M. (1981) De- fective Fc receptor functions associated with the HLA B8/DR3 haplotype. Studies in patients with dermatitis herpetiformis and normal subjects. N Engl J Med 304, 185-192.

Moller, G. (ed.) (1983) ImmunoZ Rev 70. Moretta, L., Moretta, A , , Canonica, G. W., Baci-

calupo, A , , Mingari, M. C. & Cerottini, J. C. (1981) Receptors for immunoglobulins on resting and activated human T cells. lmmunol Rev 56,

Reinherz, E. L. & Schlossman, S. F. (1981) The characterization and function of human immun- oregulatory T lymphocyte subsets. Immunology Today 2,69-75.

Reinherz, E. L. & Schlossman, S. F. (1980) Reg- ulation of the immune response. Inducer and sup- pressor T lymphocyte subsets in human beings. N Engl J Med 303, 370-373.

Salerno, A, , Caruso, C., Palmeri, P., Marras, S. , Amoroso, A. & Curtoni, E. S. (1981) Struttura della popolazione siciliana per il sistema genetic0 HLA. La Trasfussione del Sangue 26,229-240.

van Rood, J . J . , van Leeuwen, A . & Ploem, J . S. (1976) Simultaneous detection of two-cell popu- lation by two-colour fluorescence and application to the recognition of B-cell determinants. Nature

141-162.

262,795-797.

Address: Dr. Calogero Caruso Servizio di Immunologia Tissutale Istituto di Patologia generale dell’Universita Corso Tukory 211 90134 Palermo Italy