23 July, 2009

The Impact of Immunology on Human Welfare

As part of our daily lives we are constantly exposed to an extensive array of pathogens, such as bacteria, viruses and parasites. These microscopic invaders tirelessly attempt to gain entry into the cells, tissues and organs of our bodies – and yet despite this relentless barrage of germs, symptomatic disease is relatively uncommon. Key to this defence is the immune system. Over the years the combined efforts of immunologists, in understanding how the immune system functions, have impacted significantly on human welfare.

Vaccination, for example, is commonplace today; we can safely immunise both children and adults against a variety of viruses. For this, we owe a debt of gratitude to early immunologists, such as Edward Jenner and Louis Pasteur, who pioneered the development of vaccines, consequently leading to the eradication of smallpox. Whilst the number of lives that have been saved through vaccination is surely beyond comprehension, the annual influenza vaccine alone is estimated to be 70-90% effective at preventing hospitalisations from influenza complications according to the US Centers for Disease Control and Prevention.

Increased understanding of the causes of organ rejection was another significant impact of immunological research on human life, as it paved the way for successful transplantation medicine thus prolonging the lives of countless otherwise condemned patients. Specifically, the realisation that cell, tissue or organ rejection is due to a host versus graft immune response proved critical.

On a broader scale, the generation of monoclonal antibodies (MAbs), usually produced by immune cells to detect pathogens, has assisted researchers to study protein function, impacting on a diverse range of biological sciences. MAb techniques are still widely used today and their contribution to biological research, not to mention their extensive use in medical intervention, cannot be underestimated.

However, despite the continuing success stories, one area of research in need of a significant breakthrough is autoimmunity. This topic covers a number of disorders in which the body fails to discriminate ‘self’ from ‘non-self’ and consequently attacks host cells in the absence of pathogenic signals. Whilst a lot of progress has been made in several autoimmune disorders, such as rheumatoid arthritis and systemic lupus erythematosus, the underlying mechanisms causing these diseases are still unknown. As such, treatment invariably involves symptomatic relief rather than preventing disease pathogenesis.

One of the major problems in preventing autoimmunity is the inevitable unwanted side effects of potential treatments. Current strategies involve dampening the immune response in affected individuals, which treats the symptoms of autoimmunity but also leaves the patient severely immunocompromised and at risk of infection. This conundrum leads to a patient also being prescribed antibiotics and antivirals, along with their side-effects, to counteract the diminished immunity. Researchers are currently trying to bypass this problem by specifically targeting immune cells involved in autoimmune disorders, namely activated Th1 and Th17 cells, whilst sparing other uninvolved immune cells, allowing patients to maintain an adequate defence against infection. Further work is required, but it seems there may be light at the end of the autoimmune tunnel.

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