Immunotherapy is a very broad and active field: there are a great many strategies presently under development, and in various stages of maturity. All aim at making the immune system do the heavy lifting of finding and destroying specific unwanted cells, cellular machinery, and other biochemicals in the body. This is actually the immune system's evolved purpose, more or less, and so adjusting it to destroy new targets without causing harmful side-effects is a plausible near term technology. Thus there are large segments of the life science community looking into immunotherapies for cancer, immunotherapies to destroy some of the harmful aggregates that build up between cells with age, and so forth.
One of the presentations given at last year's SENS5 conference was a look at turning the immune system against harmful aggregates of tau protein - as seen in Alzheimer's disease, for example, but which happens in all brains to some degree:
One of the perils of aging is the accumulation of various protein/peptide aggregates throughout the body, some of which are associated with toxicity. In several age-related disorders, aggregates of certain amino acid sequences are much more prominent than under normal conditions, and define the disease. Harnessing the immune system has emerged in recent years as a promising approach to treat these conditions. My laboratory has worked in this field targeting the amyloid-β peptide, the prion protein, the tau protein, and more recently the islet amyloid polypeptide. The focus of my talk will be on our tau immunotherapy studies. We have shown in tangle mouse models that active or passive immunizations clear pathological tau aggregates from the brain with associated functional benefits.
A thought to leave you with: the more we see the research community working on immunotherapies for age-related conditions, there more likely it becomes that significant investments will be made into reversing the decline of the immune system. The effectiveness of these therapies to a degree depends on the effectiveness of the immune system, and that progressively fails with age - having first generation therapies in the market will ensure that there exists a strong incentive to improve those therapies, and one of the most obvious ways to do that is to rejuvenate the immune system in elderly patients.