Cold truth

Cold truth
people always think that the common cold is caused by a rhinovirus infection, the corresponding nasal congestion, sneezing, runny nose and other symptoms of the performance of the immune system fight the virus. Pok American who recently discovered that rhinovirus infection may change gene expression in the human body, leading to the above symptoms. related papers published in the br>. rhinovirus gene expression changes in human
. upregulation of anti-viral gene viperin inhibits rhinovirus replication
common cold caused by rhinovirus is the main reason
human rhinovirus (HRV) infection is the occurrence of common cold the main reason. HRV infection occurs mainly in the respiratory epithelium, but not as influenza virus infection of epithelial cells, as cytotoxicity. has been hypothesized that the virus has changed Pok biological properties of epithelial cells to induce the upper respiratory tract inflammation, making the cold Symptoms occur or worsen.
studies have shown that HRV infection, the epithelial cells produce a series of pro-inflammatory cytokines and chemokines, which seems to confirm the above hypothesis, but after HRV infection, epithelial cells can induce a number of molecules, including human b-defensin-2 (b-defensin 2) and inducible nitric oxide synthase, etc., to help the host defense response and anti-viral response, but the immune response caused by HRV specific mechanism remains unclear.
for ordinary people, HRV infection may not cause very serious problems, such as nasal congestion, runny nose symptoms often also a class a week, but for their asthma or chronic obstructive pulmonary disease (COPD) patients, HRV Infection often leads to acute respiratory inherent, even life-threatening.
Therefore, to clarify the specific mechanism of HRV infection helps people be more effective in treating colds, can also help patients with COPD and asthma and other respiratory diseases to avoid Wind Yan.
rhinovirus gene expression changes in human HRV infection
To further study the molecular mechanism of card thou Gary from Canada (Calgary) great Pok Proud (Proud), etc. with microarray (microarray) technology detection of HRV infection of airway epithelial cells were found HRV infection may alter the expression of many genes in the human body, these genes are often associated with the immune response, including chemokines and other anti-viral protein is produced.
the forward-looking, cross- sectional study included 35 volunteers were randomly divided to infection or to the Zhao group (injection of HRV-16 or placebo) in the injection before and after, respectively, whichever nasal epithelial cells, detection of gene expression. < br> injection of the virus appeared in subjects who have flu symptoms. Gene expression analysis showed that 8 hours after infection, gene expression status has not changed compared with baseline, but 2 days after infection, injection of the virus by nasal epithelial cells, representing the 6530 discrete genes (discrete genes) of 11 887 gene transcripts (gene transcripts) expression and those of Zhao significant differences.
changes in the expression of these genes, the researchers found that 471 transcripts were up-regulated at least 2-fold and 201 transcripts were down-regulated by 50 percent. upregulated genes, or control the raised chemokine inflammatory cells, or induction of interferon production, there are still some functions can produce anti-HRV protein, such as 2,5 - oligo adenosine synthase family and viperin (who has translated Viper toxins) Other genes with increased expression of cytokines and virus signal transduction and regulation of apoptosis.
In contrast, most of the downregulation of genes of unknown function, a small number of control has nothing to do with the inflammatory response of the receptor
antiviral gene viperin expression for
Previous research reports, viperin has antiviral activity, but its HRV replication is not yet clear. viperin and researchers further analyzed the relationship between HRV infection and found that viperin gene expression with some cold symptoms (rhinorrhea, sneezing and cold) were significantly related (P <0.05).
In addition, naturally occurring HRV infection and have symptoms of nasal epithelial cells, viperin gene messenger RNA (mRNA) levels increased significantly (P <0.01) (Figure 1).
to confirm HRV infection may viperin gene in epithelial cells increased, the researchers used HRV infection in vitro conditions, primary cultures of human bronchial epithelial (HBE) cells and found that, HRV-16 infection can cause significant infection of the viperin gene expression time-dependent increase In the baseline culture conditions, HBE cells did not express viperin gene Ji almost from the HRV-16 to 12 hours after infection to 48 hours, HBE cells viperin gene mRNA levels increased significantly (P <0.02) (Figure 2). < br> by small interfering RNA (siRNA) gene suppression (knockdown) technology, the researchers found that inhibition of viperin gene expression can be a significant increase in HRV replication (P <0.02) (Figure 3), thus confirming the viperin gene in the inhibition of HRV replication role.
new ideas for treatment of cold
the past it was felt that a series of cold symptoms is the performance of the immune system work. The researchers infected by HRV-depth study found that the virus infection can alter the expression of a gene which, viperin gene expression in vivo and in vitro conditions can be increased, and the rate increases with the length of time HRV infection increased. inhibit the viperin gene expression will contribute to HRV in the human body Replication.
researchers believe that the findings reveal the host response to HRV infection, but also found some new genes, which are likely to make for the future treatment of cold new ideas.
Figure 1 infection by HRV viperin gene expression increases
Figure 2 viperin gene expression and infection time-dependent inhibition of viperin
Figure 3 gene expression will contribute to HRV HRV infection can copy
viperin gene expression in the human body increases, and the increase rate of infection with HRV time related to the expression 48 hours after infection most Inhibition of viperin gene expression will significantly increase HRV replication in the human body, suggesting that viperin in the fight against HRV infection plays an important role.
(Source: Am J Respir Crit Care Med 2008,178:965-966)