New findings on AIDS non-progression

I wrote on AIDS non-progressors some time ago, yet today new information was published in Nature pertaining to the genetics behind individuals whose immune systems are seemingly miraculously able to maintain HIV from developing into full-blown AIDS.

The article explains that for some time there has been a known link between these AIDS non-progressors and the expression of the distinctive HLA B57 gene. A team of researchers led by MIT Professor Arup Chakraborty and Harvard Professor Bruce Walker observed that this gene is responsible for immune systems producing an abundance of CD8+ T cells, the killer T cells that destroy infections such as HIV. All T cells bind to foreign proteins on the surface of infected cells; they then seek out all other cells with this same particular foreign protein. The unique CD8+ T cells have the ability to not only bind to one specific protein, but seek multiple proteins and thus destroy any infections that have mutated.

The key to the function of these T cells is their interaction with self-peptides in the thymus. The variety of self-peptides in the thymus dictate the number and type of T cells that can be produced. The variety of self-peptides is a consequence of the HLA genes, including the aforementioned HLA B57.

Based on these findings that illuminate the workings of the immune system, the researchers are optimistic that this may lead to a potential "vaccine." Since all individuals possess the CD8+ T cells, the difference only being in number, they reckon they may find a way to provoke the same production of CD8+ T cells in all individuals as that of those with the HLA B57 gene. There is however one negative repercussion noted about individuals with this gene. The unique ability of these abundant T cells to bind with many proteins means it often does so with healthy cells. Individuals with the HLA B57 gene, therefore, have a high prevalence of autoimmune disease.