Why one mutation can protect people from HIV

We've talked here before about the importance of the protein CCR5 in HIV/AIDS treatment research. CCR5 is a protein on the surface of immune cells. Some people have a genetic mutation, called Delta-32, which alters how that protein works, how often it appears, or changes its structure. People with the mutation have immunity to some strains of HIV, the virus that causes AIDS.

CCR5 is the key to the Berlin Patient—Timothy Ray Brown—who, until recently, was the only person to ever be cured of AIDS. Brown received bone marrow transplants from people who had the Delta-32 mutation. His body has been HIV-free for five years. And, last week, researchers announced that two other people successfully received the same treatment.

But here's the thing, until today, I didn't totally understand how the connection between CCR5, Delta-32, and HIV worked. There's a story (and some great digital illustrations) on NPR's Shots blog that makes the situation much more clear. HIV, apparently, have little spikes all over its surface. These spikes are how the virus injects itself into cells.

When it bumps into a T cell, a finger-like projection on the cell's surface, called CCR5, pushes down on the spike. This interaction pops open the HIV and releases the infectious genes into the cell. A gene therapy could protect T cells by inactivating the CCR5 gene.

Great "A-ha!" moment for me. Read the rest of the story and look at the illustrations. It'll make some thing make a lot more sense.

Read the rest at NPR's Shots blog

PREVIOUSLY:
If AIDS Has Been Cured, Why is the Victory Party So Small?
AIDS Research Done by 17-Year-Olds

You are your bellybutton lint

Last January, at the Science Online conference, I noticed that there was a research group collecting swabs taken from the bellybuttons of scientists, science bloggers, and science journalists. That culture above? It's made from the bellybutton of Anton Zuiker, one of the organizers of that conference.

Beyond personalized petri dishes, what is the point of all this? Turns out, the goal is to learn more about the bacteria that lives on us. Some of the data from analyzing all those bellybutton samples is starting to come back, and it's turning up some interesting facts about the tiny ecological niches on our tummys.

About 18 months ago, researcher in the laboratory of Dr. Dunn, a North Carolina State University professor, came up with an idea to explore the ecology and evolution of daily life and wanted to find a spot on the body that could provide an understanding of the natural skin microbiome. They needed a place that was infrequently disturbed, avoided the scrubbing of daily wash and was common to all humans. There was no better choice than the bellybutton. Dunn and his clan of navel gazers then invited people from two conferences, 60 in total, to swab their bellybuttons and provide him with the samples, which he took back to his lab and cultured. The next several months were spent not only growing the bacteria, but also typing them to identify the species.

The first set of data is in review, but the results suggest that the bellybutton offers far more to our understanding of life and our journey through it. From these 60 people, Dr. Dunn identified close to 1,400 species of bacteria. From these, a number were predictable, such as the ever-prominent Staphylococcus epidermidis and the corynebacteria, both of which give off that "eau de germs" scent when we don't wash frequently. But others, such as those found on volunteer Carl Zimmer, were completely unexpected, such as species that are found only in the ocean or the soil or in faraway lands.

...The navel bacteria were related to where the person has lived over the course of their lifetime. The tiny anatomical vestibule was actually a museum of lifetime experiences.

Read the rest of this story by microbiologist Jason Tetro at Huffington Post.

Learn more about the Bellybutton Biodiversity Project

What a chronic ear infection looks like

These are images from the inside of two human ears. The ear on the top doesn't get chronic infections. The ear on the bottom does. The difference seems to be the presence of a biofilm—a little colony of bacteria or other microorganisms that build up in a thin layer.

Biofilms happen all over the place in nature. That slime that covers the surface of rocks at the bottom of a river or lake? That's a biofilm. The slick, green coating on the underside of a boat when you pull it out of the water? That's a biofilm, too. And so is the plaque that builds up on your teeth.

In the case of ears, though, biofilms might explain why it's so difficult to treat chronic ear infections—biofilms are not easily killed off by antibiotics. The image above, showing a biofilm-coated ear drum, was captured using a new imaging device that produces pictures from reflected light, the same way ultrasound makes images from reflected sound waves. It's part of a research paper that presents evidence about the role of biofilms in ear infection and long-term hearing loss.

Check out Scientific American for more information

Via Bora Zivkovic

Just wash your pants, people

Levi's recommends freezing jeans, instead of washing them, as a way to save water. The idea is that freezing will kill the bacteria that make your pants smell. But Stephen Craig Cary, an expert in low-temperature microbial life, begs to differ.

Science Saturday: Allergies, symbiotic bacteria, and scientific literacy

I had a great conversation with Christina Agapakis, a science blogger at Scientific American and a scientist studying synthetic biology. In this episode of Bloggingheads.tv's Science Saturday, you'll find out what Christina learned when she traced her allergies on a phylogenetic tree, why she's currently obsessed with symbiotic bacteria, why I think adults need more opportunities for informal science education after they've left school, and how scientists and educators are trying to address clashes between science and culture.

In the video, I talked about my experience at the 6th Science Center World Congress. For a little more on that, check out the story I wrote about why adults need science museums to pay more attention to them.