Jh. Check et al., A model for potential tumor immunotherapy based on knowledge of immune mechanisms responsible for spontaneous abortion, MED HYPOTH, 57(3), 2001, pp. 337-343
Citations number
71
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research General Topics
Attempts to treat various cancers by immunotherapy have been tried for abou
t 50 years. Most studies have focused on improving cytotoxic T lymphocyte (
CTL) responses against various tumors. Immunotherapy has been both active a
nd passive, and results have been modest at best. Spontaneous abortion (SAB
) of pregnancies could in some ways resemble remission of a tumor. Both tum
ors and conceptusses are faced with a similar problem - how to grow in a ho
st in a vascular rich area, and yet escape immune surveillance despite both
entities being an allogenic stimulus. In general, the fetus is far more im
munogenic than a spontaneous tumor, and yet abortuses seem to avoid CTL res
ponses but are sometimes invaded by natural killer (NK) cells. There are da
ta suggesting that SAB will occur if there is inhibition of production of a
n immunosuppressive protein called progesterone-induced blocking factor (PI
BF). This protein inhibits NK cell cytolysis and influences TH2 cytokine do
minance over TH1. If some tumors avoid NK cell destruction through a PIBF m
echanism, perhaps an active rejection of these tumors could be achieved by
inhibiting PIBF production by treating with a progesterone receptor antagon
ist. Passive immunization could also be considered by conjugative radionucl
ide or toxic chemical to a PIBF antibody which may be tumor specific since
PIBF is not produced in normal tissue. The first stop should be to see if P
IBF can be detected in the peripheral circulation in patients with certain
tumors. (C) 2001 Harcourt Publishers Ltd.