In previous articles I have discussed how biological organisms exhibit patterns that are highly analogous to computer programs written by humans. As everyone knows who works with computational devices, particularly with browser-based and mobile applications, those computer programs are vulnerable to attack by malware designed by humans to infect and harm a host computer.
Malware steals valuable sensitive and confidential information that can be used to impersonate the victim for illicit gain, or can be sold to others for the same purpose. The key to malware is to circumvent security systems and avoid detection so it can hide out on a device over time and extract the maximum amount of confidential information for nefarious purposes.
A specific type of malware is the computer virus, which is the term best known to computer users. These viruses, and other types of malware, are created by malicious humans, hackers, who are basically criminals that use their technical knowledge to break into normal computer programs. A virus finds its way onto a host computer typically through a malicious URL link, a malicious file attached to an email, or an infected USB device. It is a contagious piece of code that replicates itself by hijacking other programs through its own code on the host computer. This is what it means for a computer to be “infected” by a virus, not unlike how humans are infected when they contract a virus such as influenza (the “flu”), herpes simplex, or rhinoviruses (i.e., the common cold).
Measles on the March
A recent article in Wired Magazine explains “How Measles Hacks the Body — And Harms Its Victims for Years.” Writer Megan Molteni discusses the recent international surge in the number of cases of measles, an airborne pathogen that is among the most contagious diseases in the world, transmitted to others primarily through coughing. More interesting is how measles performs its dirty work, effectively “hacking” into the human immune system. Immune cells, like all human cells, have a diverse set of receptors on the surface that bind with specific extracellular molecules, often sending signals to the interior of the cell. These signals can be involved in regulating important immune responses to viral infections. Viruses “trick” the receptor by mimicking the cell’s normal binding partner, gaining entry into the cell where it begins to replicate itself.
As you breathe, immune cells patrol the alveoli (air sacs) of the lungs looking for foreign objects such as dust, pollen, and pathogens that they will degrade and render harmless. It has been found that a certain receptor on immune cells, the human signaling lymphocyte activation molecule (CD150, or “SLAM” for short), serves as a primary cellular receptor for the measles virus. After the measles virus binds to the CD150 receptor on the host immune cell, the immune cell unwittingly shuttles the virus to the closest lymph nodes where the virus, instead of being destroyed, hops over to the cells responsible for making antibodies that serve to remember past pathogens, and begins reprogramming those cells to make copies of itself. A week later, more than fifty percent of these cells are infected, rendering the immune system severely depleted and more prone to other types of bacterial and viral infections.
The article continues by noting that the more long-lasting effect of the measles, once a human has recovered, is the fact that the measles have essentially wiped out the body’s memory of past infections. Such “pathogenic amnesia” makes it easier to come down with bacterial and viral infections later that the immune system had previously remembered and could fight off, but now doesn’t recognize. Most of us at some point have encountered the unfortunate circumstance of information being accidentally wiped out of the memory of a computer, but in this case malfunctioning machinery can mean life or death, particularly for the very young or elderly with weakened immune systems.
Note the remarkable parallels to computer programming, which is highly technical and highly specified. We see the binding of a virus to a host cell based on well-defined interfaces. The machinery in the host cell is hacked and “reprogrammed” to crank out more copies of the virus. Memory is wiped out, weakening the immune system of the human host. On the other hand, just as we now have with computers, biological vaccines have been developed that provide active immunity by stimulating the body’s immune system to recognize a particular virus and destroy it before it has the ability to infect the body.
Considering computer programming in the hands of intelligent humans, we know that art often imitates life. With this in mind, it seems reasonable to ask whether the biological warfare going on in the trenches of our immune system is due to intelligent activity. Certainly, our need for an immune system is clear. It is also clear that the immune system, with its many interacting parts and sophisticated systems for dealing with pathogens, is a product of design.
So, is the measles virus the product of design as well? One of the lessons learned from Michael Behe’s new book, Darwin Devolves, is that living systems are complex, and that breaking or damaging a gene can have surprising effects. For example, as Behe says there, damaging the APOB gene in polar bears improves their ability to handle a high fat diet, rather than harming it. Likewise, a simple stick in the works in the right place in the immune system can set off a cascade that looks like it was planned by the stick, when in truth it was the information in the system that caused the cascade.
Which is it, then, design or dumb luck on the part of the virus? To answer that question would require studying in more detail the life history of the virus, and ultimately, an assessment of how much information can arise in the first place in this system without intelligence playing a role.
Photo: Measles virus, by CDC/ Courtesy of Cynthia S. Goldsmith; William Bellini, Ph.D. [Public domain], via Wikimedia Commons.