Human breast milk T lymphocytes display the phenotype and functional characteristics of memory T cells.
Naive (unsensitized) and memory (antigen-primed) T cells can be phenotypically distinguished on the basis of the high or low intensity with which they express a number of immunologically relevant lymphocyte membrane antigens, including CD45R, CDw29, UCHL1, LFA-1, LFA-3, CD2 and Pgp-1. Here we report that in contrast to the two major T cell subsets found in the blood, milk T lymphocytes are almost exclusively composed of the one which exhibits the CD45Rlow, CDw29, UCHL1, LFA-1high memory T cell phenotype. In addition, while milk and autologous blood cells expressed similar levels of CD3 surface antigens, CD2 and ICAM-1 expression was approximately twofold greater on the milk T lymphocytes. This agrees with the finding that whereas colostrum T cells respond poorly to PHA, they proliferate and produce interferon-gamma normally when stimulated with either the anti-CD3 or anti-CD2 monoclonal antibodies. The selective colonization of the mammary gland during lactation by a population of T lymphocytes which displays the phenotype and functional characteristics of memory T cells may be one of the mechanisms whereby the suckling infant benefits form its mother's immunological experience.
Bertotto
A
A
Department of Paediatrics, University Medical School, Perugia, Italy.
Gerli
R
R
Fabietti
G
G
Crupi
S
S
Arcangeli
C
C
Scalise
F
F
Vaccaro
R
R
D000911:Antibodies, Monoclonal / Q000276:immunology; D002455:Cell Division; D005260:Female; D006801:Humans; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis; D008895:Milk, Human / Q000276:immunology* / Q000378:metabolism; D010641:Phenotype; D010835:Phytohemagglutinins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D010835:Phytohemagglutinins; D007371:Interferon-gamma