EFFECTS OF DNA / RNA EXOGENOUS PLANTS FROM GENETICALLY MODIFIED ON THE HUMAN IMMUNE SYSTEM
Werner Müller
Summary
Werner Müller
Summary
The immune system of human beings has two aspects, the innate and adaptive. Recognizes the innate universal patterns-the so-called pathogen-associated patterns, has persisted throughout evolution, works through recognition receptors (from here, RR) and is "the first line of defense" [1] .
desoxirribolucleico acid sequences (DNA) and ribonucleic acid (RNA) are associated models pathogens that have immunomodulatory functions [2]. Many RR belong to the family of receptors tolls (toll-like receptors or TLR) receptor TLR3 recognizes double-stranded RNA, TLR7 and TLR8 recognize the the single-stranded RNA and TLR9 is a receptor for CpG DNA [ 3]. In addition, there are independent TLR also recognize DNA and RNA.
Genetically modified plants contain synthetic genes (DNA sequences) that do not exist in any living species. Scientists have succeeded in producing genetically modified plants, but it did not take into account the old and universal patterns of DNA sequences, the only immune system recognized. During digestion, are fragments of DNA from food and synthetic sequences that do not degrade completely in the intestine and can be detected in the lymph system, blood and some organs like the liver, spleen and muscles. In such locations has been detected immunomodulatory activity of bacterial DNA from food.
is quite likely that the presence in the blood, liver, etc. fragments of synthetic DNA sequences from genetically modified plants will lead to immunomodulatory activity remains unknown. Since genetically modified plants containing synthetic DNA sequences that are new the immune system, immunomodulatory activity may be very different from that developed along the front human evolution "DNA sequences of natural foods." The EU authorities responsible for food safety (EFSA) [4] have been saved, and still keeping silent about this problem ".
To date, the immunomodulatory activity of synthetic DNA sequences from genetically modified plants is still excluded from the risk assessment. Urge the development of an exploratory orientation (or of a research program) to analyze the immunomodulatory activity of synthetic DNA sequences from plants genéticamente modificadas. La seguridad de éstas en relación con la salud de los seres humanos no podrá determinarse sin haber clarificado previamente cuestiones inaplazables como éstas.
Extracto : Captación de ADN alimentario en los tejidos de los mamíferos
Introducción
El riesgo alimentario para la salud humana que representan el ADN y el ARN de plantas transgénicas sigue aún sin recibir la atención que merece. El principal argumento que se solía esgrimir es que el ADN de los alimento se degrada por completo en el tubo digestivo. A pesar de que en sangre de ratones se han detectado casos de captación de ADN procedente de alimentos (Schubbert et al. 1994), se considered that such cases were rare, not widespread (ILSI 2002). But this view has changed completely as numerous studies have been showing that the absorption of dietary DNA in blood and various organs is a widespread phenomenon, not an exception. The group Schubbert Doerfler and was one of the first to demonstrate that the DNA of M13 virus given orally reaches the bloodstream (Schubbert et al. 1994), peripheral leukocytes, spleen and liver via the intestinal mucosa and can bind covalently to DNA in the mouse (Schubbert et al. 1997).
Exogenous DNA administered orally to pregnant mice was detected in various organs of fetuses and pups of the litter. The DNA fragments of M13 virus consists of approximately 830 base pairs. By the method of Fish (fluorescent in situ hybridization) identified clusters of cells containing exogenous DNA in various organs of rat fetuses. Exogenous DNA is invariably located in cell nuclei (Schubbert et al. 1998). Subsequent studies have found similar results (Hohlweg and Doerfler 2001, Doerfler et al. 2001b).
addition to studies on mice, conducted research with farm animals have given scientists a more complete picture of this problem. Einspanier et al. (2001) found fragments of the genome of maize genes in blood and lymphocytes from cows fed with the product. Reuter (2003) obtained similar results in pigs. Have also been detected over the maize genome in all tissue samples obtained from chickens (muscle, liver, spleen, kidneys). Have detected evidence of DNA even in milk food Einspanier et al. 2001, Phipps et al. 2003), as well as raw pork meat (Reuter 2003, Mazza et al. 2005). DNA has also been detected in human food (Forsman et al. 2003).
The mechanism of DNA entry into the lymphatic system in the bloodstream and tissues has not yet been elucidated, but it is believed that the Peyer's patches play an important role in the absorption of dietary DNA. Peyer's patches are lymphoid nodules of cells grouped into clusters or patches in the mucosa of the ileum, the distal portion of the small intestine (www.britannica.com and [5]).
In 2001 it was hypothesized that, contrary to what happens with the DNA of normal foods, DNA synthetic food from transgenic plants would be completely degraded, as Einspanier could not detect synthetic DNA, but only natural DNA . But Mazza et al. (2005) showed that may also be synthetic fragments of transgenes (maize GM Mon 810) in the blood and some organs like the spleen, liver and kidneys. It is unclear why other scientists have not detected synthetic DNA in the body. Perhaps it could be due to differences in the sensitivity of the techniques used and the differences between the primers used [6]. Some researchers have made inadvertent use of primers that are common breakpoints (although unknown) of the synthetic gene.
is an indisputable fact that the blood system absorbs dietary DNA fragments of synthetic DNA and genetically modified plants, but the assumptions that have been issued on implications of these results vary widely.
In its conclusions, both Mazza et al. (2005) as Einspanier et al. (2001) denied the existence of risk associated with blood absorption of synthetic sequences, arguing that the absorption of DNA in blood is a natural phenomenon and the effects of the DNA sequences of synthetic foods on the body may be the same-if that there is some effect that the DNA of normal foods. ILSI, a group of study related to the European industry (ILSI 2002), supports this view.
But these conclusions must be regarded as mere assumptions, as neither Mazza et al. (2005) or Einspanier et al. (2001) nor the ILSI (2002) have investigated the effects of dietary DNA.
It should be noted that some researchers in the field of immunology (but not dealing with risk assessment of transgenic plants) have reported specific effects of foreign DNA, and this regardless of how it has been administered (by intragastric catheter, injected or orally). Rachmilewitz et al. (2004) investigated the immunostimulatory effect of probiotic bacteria DNA [7] and in the presence of DNA in the blood and organs of mice. They concluded that the location of bacterial DNA in these bodies match their immunostimulatory activities.
It therefore seems likely that the presence detected in various organs and blood for DNA from other common foods and synthetic can match also with immunomodulatory activities have not yet investigated and therefore unknown. Perspectives
In a review of scientific literature, Kenzelmann et al. (2006) noted that the genome is more conserved than ARNnc regions of protein coding sequences of DNA, which highlights the importance of nucleic acid regulatory network of human beings. Recent research has shown that RNA plays a key role in building complex networks regulatory (Mattick 2005, Kenzelmann et al. 2006). The interaction between non-coding DNA (RNA genes, introns [8] from protein-coding genes, gene intron RNA) and cells are not yet elucidated. Until recently research has focused mainly on proteins, which underestimated the role of RNA, but now research has changed dramatically guidance to focus on the abundant RNA and its regulatory functions.
To date, the European Food Safety Agency (EASA) has been reluctant to take notice of these dramatic changes in cell biology and to incorporate the new discoveries in the risk assessment of genetically modified plants, which is still based on proteins. For unknown reasons, the agency ninguneo the potential effects of synthetic DNA and RNA of genetically modified plants in the regulatory network of human beings. It is hoped that this report will serve to make research more focused on the potential effects of synthetic DNA and RNA of genetically modified plants on the human immune system.
Since the risk assessment and basic knowledge of molecular biology are highly correlated, we predict that "the failure to recognize the importance of RNA produced by noncoding regions (introns, RNA genes, pseudogenes, etc..) can be one of the biggest mistakes in the history of risk assessment related to transgenic plants. The human genome has the highest number of non-coding RNA sequences. Therefore, humans are probably the most sensitive species to the new synthetic DNA and RNA produced by genetically modified plants. "(John S. Mattick, Director of the Institute for Molecular Bioscience. University of Queensland (Australia).
Notes Reviewer .- [1] The immune system is responsible for defense against aggressive microorganisms that have attacked humans over the millennia, the so-called "Pathogens" - which retains a "memory" of gene-protein strategic specialized cellular sites. These proteins, called receptors - trigger the alarm when he recognized the attacker turn and set in motion the immune and inflammatory responses designed to neutralize.
