ISSN:
1573-7373
Keywords:
natural killer cell
;
pituitary
;
pituitary adenoma
;
folliculo-stellate cell
;
neuroendocrine-immune interaction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Natural killer (NK) cells are specialized lymphocytes which arecharacterized as non-T and non-B cells, as they lack classic T and B cellsurface markers. Recently, NK like immunoreactivity has been identified inendocrine and neuronal tissues as well as in the tumors derived from theneuroectoderm and neuroendocrine system. We examined the expression of NK-1like immunoreactivity in 6 normal pituitary glands and in 55 cases ofneoplastic pituitaries (16 growth hormone (GH) producing adenomas, 14prolactin (PRL) producing adenomas, 4 thyrotropin (TSH) producing adenomas,5 adrenocortocitropin (ACTH) producing adenomas and 16 non-functioningadenomas) immunohistochemically. The expression of the S-100 protein, whichis a marker for folliclo-stellate (FS) cells, which have been reported tosecrete cytokines as immuno-endocrine modulators, were also examined. Innormal pituitary glands, NK-1 was detected in all 6 tissues in the cytoplasmof about 5–10% of the anterior pituitary cells. By serialsectioning and double immunostaining, NK-1 immunopositivity was frequentlyfound to be localized in ACTH cells. The colocalization with other anteriorpituitary hormones such as GH, PRL, the beta-subunit of luteinizing hormone(LHβ), follicle stimulating hormone (FSHβ), TSHβ andα-subunit of glycoprotein (αSU) was not observed. The S-100immunopositive FS cells, which were scattered among hormone producing cells,were closely associated with NK-1 immunoreactive cells in the normalpituitaries. Among the 55 cases of pituitary adenomas, NK-1 was present inall the types of pituitary tumors, and a total of 33 (60.0%)contained NK-1 positive tumor cells. The frequency of NK-1 immunoreactivityin the individual adenoma types was; 14 of 16 GH producing adenomas(87.5%), 7 of 14 PRL producing adenomas (50%), 3 of 4 TSHproducing adenomas (75%), 3 of 5 ACTH producing adenomas(60%), and 5 of 16 nonfuctioning adenomas (31.3%). By doubleimmunostaining, NK-1 was found to be frequently colocalized with ACTH inACTH producing adenomas, and was colocalized with PRL in PRL producingadenomas, or with GH, PRL or the α-subunit in GH producing adenomacells. NK-1 immunoreactive cells were observed in close association withS-100 immunopositive FS cells in the adenomas. Our results may indicate thatNK-1 positive cells may have functions as a paracrine modulators of theirneighboring cells, which includes S-100 positive FS cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1005899717286
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