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Because interferon-␥ (IFN␥) is present in the central nervous system during neurologic diseases associated with inflammation, its effect on endotoxin-induced cytokines was studied. Cerebrospinal fluid (CSF) and serum levels of interleukin (IL)-1␤, IL-6, and tumor necrosis factor-␣ (TNF␣), their messenger RNA expression in brain areas (hypothalamus, hyppocampus, and striatum) and in spleen were evaluated 2 and 8 h after endotoxin [lipopolysaccharide (LPS), 25 g/rat icv], IFN␥ (2.5 g/rat icv) or after their coadministration in rats. CSF and serum IL-1␤ levels were increased by LPS alone and IFN␥ coadministration did not furtherly increase them. IFN␥ potentiated LPS effect on IL-6 and TNF␣ levels in both CSF and serum. LPS and IFN-␥ coadministration did not alter IL-1␤ messenger RNA expression induced by LPS in brain areas and in spleen, but it potentiated that of IL-6 and TNF␣. The present in vivo data show that icv coadministration of LPS and IFN␥ results in a potentiation of cytokine production (IL-6 and TNF␣) which may trigger a cascade of events relevant to neurodegenerative processes. This action is independent of IL-1␤ because the production of this cytokine is not altered by IFN␥ treatment. (Endocrinology 138: 5220 -5226, 1997)

The human folate receptor (FR) is overexpressed in ovarian carcinoma. FR transcripts are heterogeneous due to the use of two promoters, P1 and P4, and alternative splicing of exon 3. RNase protection assay and RT-PCR revealed higher levels of the transcripts that include exon 3 in lines and specimens from ovarian carcinoma. A P1^chloramphenicol acetyltransferase (CAT) construct containing exon 3 demonstrated efficient reporter expression only in ovarian carcinoma. 5P P and 3P P deleted variants of the P1^CAT construct were analyzed by RT-PCR of the exogenous transcripts and reporter activity. A 5P P splice site and 35 bp downstream intronic region of exon 3 appeared to regulate enhanced FR expression in ovarian carcinoma. ß 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

The alpha-folate receptor (alpha FR) is overexpressed in 90% of nonmucinous ovarian carcinomas. In addition to the known role of alpha FR binding and mediating the internalization of folates, functional interaction of alpha FR with signaling molecules was recently shown. To identify a model to study the role of alpha FR in ovarian carcinoma, we characterized the alpha FR gene in the ovarian carcinoma cell line CABA I in comparison to a reference line, IGROV1. In CABA I cells, Northern blot analysis revealed an alpha FR transcript of the expected length and FACS analysis indicated receptor expression on the cell membrane; however, RNase protection assay revealed no specific signals. Southern blot and genomic PCR analysis suggested the presence of a rearrangement(s) involving the 5' region of the gene in CABA I cells as compared to IGROV1 cells. Cloning and sequencing of CABA I alpha FR cDNA revealed several point mutations. The partitioning of alpha FR in membrane microdomains from CABA I cells and its association with regulatory molecules was comparable to that of IGROV1 cells. By contrast, the alpha FR expressed on the CABA I cell membrane bound folic acid with lower affinity, and ectopic expression of the corresponding cDNA in CHO cells confirmed impaired folic acid binding. Thus, CABA I cells may provide a tool to delineate functional domains of the alpha FR.