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Human milk T lymphocytes are mostly HML-l-positive cells A. Bertotto, G. Castellucci, E Scalise, and R.Vaccaro Department of Paediatrics, Perugia University Medical School, 1-06100 Perugia, Italy Received July 10, 1991 / Accepted July 11, 1991 Sir: H u m a n colostrum and milk contain a substantial n u m b e r of i m m u n o c o m p e t e n t cells, including lymphocytes of the T-cell lineage [7]. Several lines of evidence suggest that the phenotypic and functional characteristics of milk T-lymphocytes are different from those of their counterparts circulating in the bloodstream. Firstly, the great majority of colostral T-cells selectively react with monoclonal antibodies ( M A B ) which identify antigen-primed m e m o r y T-cells [2]. Secondly, in vitro proliferation assays have shown that T-lymphocytes in colostrum respond poorly to phytohaemagglutinin [2, 4, 5], whereas their response to a variety of bacterial and viral antigens [4-6, 8] and agonist M A B which bind to either the CD3 or CD2 m e m b r a n e receptors [2] is normal. Thirdly, the y/8 T-cell n u m b e r is twofold greater in early m a m m a r y secretions than in peripheral blood [1, 3]. Although these findings suggest that T-cells do not accumulate randomly in colostrum, but rather are directed there by a selective homing process, their origin remains enigmatic. The present investigation shows (Table 1) that an overwhelming preponderance of colostral T-cells react with a M A B (HML-1, kindly supplied by Dr. N. CerfBensussan, I N S E R M U N I T 132, H6pital des Enfants Malade, Paris, France) directed against conformational epitopes expressed by intestinal intra-epithelial lymphocytes [9]. This is the reverse of the situation encountered in peripheral blood, where H M L - 1 § T-cells are virtually absent. These phenotypical findings are the first evidence that the human gut-associated lymphoid system is in same way immunologically related to exocrine tissues, including the lactating m a m m a r y gland.

Table 1. HML-1 antigen co-expression by human colostral T-cells (CD3+) a Source of lymphocytes

Samples tested

CD3+/HML-1 +

(n) Milk Autologous blood Heterologous blood

10 8 6

77 (61-98) b 0 0

a Data obtained by indirect immunofluorescence followed by twocolour cytofluorimetric analysis. Anti-CD3 MAB (OKT3) was purchased from Ortho, Raritan, NJ, USA b Relative percentage of positive cells expressed as mean and (range) Abbreviation." MAB = monoclonal antibody

References 1. Bertotto A, Castellucci G, Fabietti G, Scalise F, Vaccaro R (1990) Lymphocytes bearing the T-cell receptor y8 in human breast milk. Arch Dis Child 65 : 1274-1275 2. Bertotto A, Gerli R, Fabietti G, Crupi S, Arcangeli C, Scalise F, Vaccaro R (1990) Human Breast milk T lymphocytes display the phenotype and functional characteristics of memory T cells. Eur J Immunol 20 : 1877-1880 3. Bertotto A, Gerli R, Castellucci G, Scalise F, Vaccaro R (1991) Human milk lymphocytes bearing the y/~ T-cell receptor are mostly 5TCSl-positive cells. Immunology (in press) 4. Ogra SS, Ogra PL (1978) Immunologic aspects of human colostrum and milk. II. Characteristics of lymphocyte reactivity and distribution of E-rosette forming cells at different times after the onset of lactation. J Pediatr 92: 550-555 5. Oksenberg JR, Persitz E, Brautbar C (1985) Cellular immunity in human milk. Am J Reprod Immunol Microbiol 8 : 125-129 6. Parmely MJ, Reath DB, Beer AE, Billingham RE (1977) Cellular immune response of human milk T lymphocytes to certain environmental antigens. Transplant Proc 9 : 1477-1483 7. Richie ER, Bass R, Meistrich ML, Dennison DK (1982) Distribution of T lymphocytes subsets in human colostrum. J Immunol 129 : 1116-1119 8. Ruben FL, Holzman IR, Fireman P (1982) Response of lymphocytes from human colostrum or milk to influenza antigens. Am J Obstet Gynecol 143:518-522 9. Ullrich R, Schieferdecker HL, Ziegler K, Reicken EO, Zeitz M (1990) y/8 T cells in the human intestine express surface markers of activation and are preferentially located in the epithelium. Cell Immunol 129 : 619-627

Reye syndrome G. Veereman-Wauters and R. Dimand Departments of Pediatric Gastroenterology and Intensive Care University of California, Medical Center, San Francisco, CA 94 143, USA Received August 20, 1991 ! Accepted August 20, 1991

Sir: We read with interest the p a p e r on " R e y e syndrome or side-effects of anti-emetics?" by M. Casteels-Van Daele [1], and share the author's opinion that Reye syndrome now appears to be extremely uncommon. A t our institution we have not seen a case of Reye syndrome over the last 3 years. Two children (a 10-month old boy and an 18-month-old girl) who were referred with the diagnosis of possible Reye syndrome, have docu m e n t e d long chain and medium chain acyl C o A dehydrogenase deficiency respectively. A high suspicion for drug and metabolic toxicity in children presenting with a "Reye-like syndrome" is certainly indicated.

Reference 1. Casteels-Van Daele (1991) Reye syndrome or side-effects of anti-emetics? Eur J Paediatr 150 : 456-459

Human milk T lymphocytes are mostly HML-1-positive cells.

150 Human milk T lymphocytes are mostly HML-l-positive cells A. Bertotto, G. Castellucci, E Scalise, and R.Vaccaro Department of Paediatrics, Perugia...
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