Detection of elevated serum beta-chemokine levels in seronegative Chinese individuals exposed to human immunodeficiency virus type 1.

The mutations in the CCR5 coding region, such as CCR5Delta32 and CCR5m303, that suppress the transmission of human immunodeficiency virus (HIV) type 1 do not exist in Chinese people. However, 9 Chinese subjects in Taiwan with histories of multiple sexual exposures to HIV remained uninfected, suggesting that certain anti-HIV factors do indeed exist. Experiments were therefore designed to investigate the immune mechanism that protects this cohort against HIV infection. Peripheral blood samples from these 9 subjects and 7 healthy people who had not been exposed to HIV were obtained for the quantitation of the levels for beta-chemokines and interleukin 16 (IL-16) in serum samples or secreted by peripheral blood lymphocytes. Significantly higher serum levels for nearly all 3 beta-chemokines, regulation on activation, normal T cell-expressed and secreted, macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta (P<.05, P<.05, and P=.05, respectively), but not IL-16, were detected in the 9 HIV-uninfected subjects as compared with control subjects. The result suggests that among the host genes and cellular factors thus far identified, beta-chemokines are the major HIV-suppressive factors that protect Chinese people from infection with HIV.

Microarray profiling of gene expression patterns in bladder tumor cells treated with genistein.

Microarray technology was used to gain an insight into the molecular events of tumor cell growth inhibition mediated by the soy isoflavone genistein. For this, a susceptible bladder tumor line TCCSUP was treated with the inhibitory dose (50 microM) of genistein for various periods of time, followed by mRNA isolations, cDNA probe preparations, and hybridization individually to cDNA chips containing 884 sequence-verified known human genes. After analyzing the hybridization signals with a simple quantitative method developed by this study, we detected that egr-1, whose expression has been associated with proliferation and differentiation, was transiently induced and this expression pattern was later confirmed by RT-PCR. Thus, microarray technology is a reliable and powerful tool for profiling gene expression patterns in many biological systems related to cancer. We further detected many groups of genes with distinct expression profiles and most of them encode for proteins that regulate the signal transduction or the cell cycle pathways. These genes warrant further investigation as regards their roles in the susceptibility of the tumor cell line to the antitumor drug.

Influence of nucleotide polymorphisms in the CCR2 gene and the CCR5 promoter on the expression of cell surface CCR5 and CXCR4.

Polymorphisms in the CCR2 gene (CCR2-64I) and the CCR5 promoter (pCCR5-59029G) have been correlated with slower HIV-1 disease progression. How these polymorphisms influence the rate of AIDS progression has remained unclear. We have therefore investigated whether these nucleotide polymorphisms will reduce the expression levels of surface CCR5 and CXCR4, and thus lead to slower AIDS progression. For this, a cohort of Chinese volunteers in Taiwan was subjected to the determination of CCR2 and pCCR5 genotypes followed by analysis of the surface CCR5 and CXCR4 expression on five cell types derived from peripheral blood mononuclear cells by flow cytometry. Several significant associations were detected between genotypes and expression levels of the proteins. The most important finding was that an increased number of CD4(+) cells expressing CCR5 correlated with pCCR5-59029A homozygosity without the interference of both the CCR2-64 and the CCR5 delta 32 (deleted 32 bp) mutations (P: = 0.0453), which is consistent with the previous data on the association of the genotype to AIDS progression. Since different genetic polymorphisms co-exist in human beings, the rate of AIDS progression as well as the risk of rheumatoid arthritis may be governed by the interplay of the array of nucleotide changes and their affected proteins.

Characterization of a desiccation-related protein in lily pollen during development and stress.

This work characterizes a lily (Lilium longiflorum Thunb. cv. Snow Queen) anther (LLA) protein associated with desiccation. Peptide mapping analysis revealed that the abundant LLA-23 doublet contained similar polypeptides, having an isoelectric point of 6.1. Immunoblots of pollen protein from developing anther/pollen confirmed that the LLA-23 protein accumulated only at the later stage of pollen maturation and that the levels remained steady in mature and vital pollen. The accumulation of LLA-23 proteins was correlated with desiccation that naturally occurred in pollen. Subcellular fractionation of pollen proteins revealed that the protein was located in the cytoplasmic fraction. Premature drying of developing pollen confirmed that the concomitant accumulation of LLA-23 was associated with desiccation. Peptide sequence analysis demonstrates similarities between the lily LLA-23 and a family of water-deficit/ripening-induced proteins including LP3 of pine, DS2 of potato, and Asr of tomato and pummelo. In addition, the concomitant accumulation of LLA-23 can be experimentally manipulated by methyl jasmonate (Me-JA) and salicylic acid (SA) as well as by mannitol and methyl viologen. The LLA-23 represents a novel member of the water-deficit/ripening-induced proteins.