The emerging role of cell engineering in treating diseases

Cell engineering is a rapidly evolving technology to treat diseases by controlling and directing cellular networks in the body. Whereas gene therapy seeks to alter the genetic makeup of cells, cell engineering goes a step further to consider how cells interact and ultimately function.

Cell engineering is based on understanding how cells function in the body and how to alter these functions to achieve therapeutic success. Cells communicate with each other in response to changes in their environment. Cells receive signals from other cells and transmit another signal to other cells to achieve specific biological functions. Cell engineering controls this process by providing molecular tools that direct the input cells receive, leading to a desired output.

CAR T cell technology is an example of cell engineering developed as a customized response to treat cancer. The patient’s own cells are genetically modified to produce a specialized receptor on its surface. The engineered T cells are thereby reactivated to attack cancer cells.

Cell engineering can also be applied to multicellular networks to achieve tissue remodeling and regeneration of tissues. Potential applications of cell engineering include controlling autoimmunity, inflammation, regeneration and repair of tissues, and even synthesis of new organs.

Engineered cell therapies offer advantages over currently used molecular therapies, such as biologics or drugs. They can be less toxic as they are more targeted in action and do not interfere with other biological functions. Cell therapies can also aid in homeostasis or balance in body functions.

In addition to cancer, cell therapies could benefit other therapeutic areas. In cases of autoimmunity or inflammation, the goal is suppression. In the regeneration or repair of injury sites, cell therapies could induce targeting, cell differentiation, and blood vessel growth at the injury site.

REFERENCES
Lim, Wendell. “The emerging era of cell engineering: Harnessing the modularity of cells to program complex biological function.” Science. 378;6662; 848-851.

T cells treat squamous cell carcinoma

Immunotherapy and Autoimmune Complications

Immunotherapy has resulted in great achievements in cancer treatments. However, significant adverse side effects have also occurred, often resembling autoimmune diseases.

Harnessing the immune system to treat cancer has long been a dream of researchers and oncologists. After overcoming many obstacles, success seems to have been achieved. An essential feature of the immune system is its ability to distinguish “self,” the body’s own cells and tissues, from “non-self,” originating from outside the body. Cancer cells are derived from normal body cells, so the immune system must somehow recognize them as “non-self” to attack them. Although there is ample evidence that the immune system detects abnormalities in cancer cells in the early stages, the cancer cells have developed many methods to evade the immune system. Immunotherapy, such as the use of checkpoint inhibitors is based on stimulating the immune system to detect and destroy cancer cells. Immunotherapy employs unique molecules present on the surface of cancer cells.

The development of autoimmunity is likely an inherent risk in immunotherapies. Considerable effort is underway to unravel the intricacies of adverse immune reactions to predict when adverse events are likely to occur. New therapies should minimize adverse events while maintaining the effectiveness of checkpoint inhibitors.

Improving immunotherapy strategies can involve identifying differences in antibodies present in autoimmunity resulting from immunotherapy with antibodies present in conventional autoimmunity. also, differences in quantities and types of immune cells can be observed between the two types of autoimmunity. This knowledge can be useful in choosing appropriate immunotherapy regimens.

Individual differences are important, as some individuals may have a genetic predisposition for autoimmunity. The unique composition of the individual’s microbiome may impact the development of autoimmunity by altering the immune composition of the tumor and its microenvironment. This immune composition may alter immune responses to immunotherapy treatments.

REFERENCES
1. Couzin-Frankel, Jennifer. “Researchers tackle vexing side effects of potent cancer drugs.” Science. 2022 Sept. 2; 377 (6610): 1028-1029.
2. Weinmann, Sophia and David Pisetsky. “Mechanisms of immune-related adverse events during the treatment of cancer with immune checkpoint inhibitorts.” Rheumatology. 2019:58: vii59-vii67.
3. Young, Arabella, Zoe Quandt and Jeffrey Bluestone. “The balancing act between cancer immunity and autoimmunity in response to immunotherapy.” Cancer Immunol Res. 2018 Dec; 6 (12): 1445-1452.

Treating Cancer with Immunotherapy and Targeted Therapy

The development of new cancer therapies has been proceeding at
an astounding rate. These advancements have led to publishing
a second edition of Treating Cancer with Immunotherapy and
Targeted Therapy two years after the first edition.
A more comprehensive understanding of the process of
metastasis has unfolded, leading to the prospect of developing
drugs targeting metastasis. The role of cancer stem cells in the
process is also discussed.

Many new therapies are discussed. An overall theme appears
to be that they are most effective in combination with other
therapies. Combination therapies have led to a reexamination
and renaissance in the use of cancer vaccines. Advances in
messenger RNA technology have resulted in the development of
highly effective mRNA vaccines.

The uses of oncolytic viruses and bispecific antibodies represent
new approaches to immunotherapy. Applying CRISPR
technology to cancer therapy appears promising but is only in
the very early stages of development. The microbiome has vast
influences on human health, the immune system, and cancer
development, and the microbiome’s composition has shown to
affect the outcome of cancer therapies.

The field of cancer therapy is constantly evolving, and this book
is a concise summary of a vast field.

Updates: Subsequent issues of this newsletter will provide new developments in the fields of cancer immunotherapy and targeted therapy since the publication of the second edition.

Vegetable platter

Immunosenescence and Nutrition

Nutrients affect many essential functions in the development and functioning of the immune system. Scientists agree that deficiencies in nutrients can cause immune function impairment, which can be reversed by nutrient supplementation. Controversy exists whether supplementation above levels required to reverse the effects of deficiencies can further augment the normal immune system.

Older adults are more subject to nutrient deficiencies than younger people due to a variety of causes. Therefore, it is essential to keep alert to older adults’ nutritional status and supplement diets when necessary.

Studies have been conducted on apparently healthy older adults to see if further supplementation of specific vitamins and other nutrients could help alleviate immunosenescence (the decline in immune function in the elderly). The design of studies to determine the effects of supplementation on immunity are critical and may account for some of the conflicting results obtained.

Vitamin D can stimulate the innate immune system but could be inhibitory to the adaptive immune system. Clinical studies have shown conflicting results.

Studies on vitamin E supplementation above recommended levels for the aged have shown to enhance the immune response.  However, clinical studies on vitamin E’s effect on infection have demonstrated conflicting results due to confounding factors.

Zinc deficiency, common in the elderly, is linked to impaired immune function and increased risk for acquiring infection, which can be corrected by zinc supplementation. However, higher than recommended upper limits of zinc may adversely affect immune function.

Probiotics are live bacteria found in the intestinal tract in sufficient numbers to provide health benefits to the host. Probiotics are thought to regulate immune function in the gastrointestinal tract through interaction with intestinal epithelial cells.

Research on probiotic supplementation shows promise, but results are inconsistent. Probiotics include a wide variety of species and strains, and any immune effects noted could be strain specific. Additionally, probiotics may need to be used for an extended period of time before demonstrating a significant effect.

Whole diet approaches, particularly the Mediterranean diet, suggest that they positively influence several age-related diseases and improve immune responses.

Featured Image: Vegetables as sources of nutrients

Creator: Katrin Gilger

License: CC BY-SA 2.0

 

References

  1. Alam, I., et al. “the immune-nutrition interplay in aging – facts and controversies.” Nutrition and Healthy Aging. Vol. 5 (2019) pp. 73-5. https://content.iospress.com/download/nutrition-and-healthy-aging/nha170034?id=nutrition-and-healthy-aging%2Fnha170034
  2. Pae, M., Meydani, S., and Wu, D. “The Role of Nutrition in Enhancing Immunity in Aging.” Aging and Disease. Vol. 3,Issue 1, pp 91-129. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3320807/pdf/ad-3-1-91.pdf
  3. Ramalho, R. “Immunosenescence and nutrition: reviewing clinical vidence on pre-, pro- and synbiotics in aging.” J. Allergy Immunol. Vol. 1, Issue 1 pp.1-7. https:www.oatext.com/pdf/JAI-1-105.pdf
  4. Wu, D., et al. “Nutritional Modulation of Immune Function: Analysis of Evidence, Mechanisms, and Clinical Relevance.” Front. Immunol. 15, 2019. https://www.frontiersin.org/articles/10.3389/fimmu.2018.03160/full
Immunosenescence illustration

Immunosenescence

Immunosenescence

Immunosenescence can be defined as immune function changes that contribute to the increased susceptibility to disease in older people. A related term is inflamm-aging, the persistence of chronic inflammation characteristic of immunosenescence.

The immune system consists of two branches, the innate system, and the acquired system. The innate system is the first line of defense of the body and consists of physical barriers such as skin and mucus membranes and various immune cells. The adaptive immune system develops from an antigen stimulus, such as an invading organism, and consists of T and B lymphocytes.

A significant change occurring in the innate immune system with immunosenescence is the appearance of chronic inflammation, caused by the increased production of pro-inflammatory cytokines.

Immunosenescence is characterized by a decline in acquired immunity, resulting in a reduced ability of older persons to respond to new infections and vaccines. Specifically, immunosenescence results in a decrease of naïve T and B cells. Naïve T or B cells have not yet been exposed to an antigen (an infectious agent). An increase in memory T and B cells (resulting from previous infections) are observed. These changes are thought to be partly due to the involution of the thymus (where T cells are produced).

A decrease in CD4 T helper cells occurs. CD4 T cells play essential roles in the functioning of the adaptive immune system.

Inflamm-imaging is characterized by an increase in pro-inflammatory cytokines. Cytokines are cell signaling molecules that aid cell to cell communication in immune responses and stimulate cells’ movement towards sites of inflammation, infection, and trauma. Interleukin-6 is a particularly detrimental cytokine.

The second article in this series will discuss the uses of nutrients for the prevention and treatment of immunosenescence.

The third article will discuss proposed non-nutritional treatments for immunosenescence. These proposed treatments must undergo further clinical trials to demonstrate their safety and effectiveness.

Attribution of image:

Creator: Raquelbusto

License: CCBY-Share Alike 4.0

http://creativecommons.org/licenses/by-sa/4.0/legalcode

 

References

  1. Aiello, A. et al. “Immunosenescence and Its Hallmarks: How to Oppose Aging Strategically? A Review of Potential Options for Therapeutic Intervention. Frontiers in Immunology”. Sept 2019. Vol. 10, Article 2247 https://www.frontiersin.org/articles/10.3389/fimmu.2019.02247/full
  2. Aw, Danielle, Alberto Silva and Donald Palmer. “Immunosenescence: emerging challenges for an ageing Population.” Immunology, 120,435-446. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2265901/
  3. Castle, Steven. “Clinical Relevance of Age-Related Immune function.” Clinical Infectious Diseases.” 2000;31: 578-85. https://academic.oup.com/cid/article/31/2/578/299255
  4. Ventura, Maria. “Immunosenescence in aging: between immune cells depletion and cytokines up‑” Clinical and Molecular Allergy. 2017, 15: 8 Bio Med Central https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5731094/pdf/12948_2017_Article_77.pdf

 

How the Microbiome Affects Cancer

The microbiome refers to the collection of all the gene sequences from a community of microbes in the human body. The microbiome has many effects on the human body and may promote cancer progression or aid in controlling cancer. The interactions between the microbiome, diet, host factors, drugs, and cell interactions are complex. Studying the nature of these interactions will require a systems approach.

 

The microbiome may interact with cancer in two ways:  direct interaction (between microbes residing in tissues where cancer emerges), or indirect interaction (between the microbiome and a cancer living in a different tissue). Metastases can carry bacteria from the microbiome of primary tumors to distal tissues.

 

The gut microbiota is closely involved in the development and regulation of the immune system. The immune system is a fine-tuned balance. It must be activated to fight infections, but then deactivated when the threat is overcome to avoid damaging the body’s tissues.  Inflammation is an essential feature of the immune response and can alter the composition of the microbiome so that it can either promote or act against cancer. Some antigens from gut microbes could be similar to cancer antigens resulting in training the immune system to fight cancer.

Patients treated with antibiotics before immunotherapy or chemotherapy fared poorer than patients without antibiotic treatment. The antibiotics may have eliminated beneficial bacteria. Determining the specific species of bacteria responsible has been challenging. In two studies, researchers collected fecal samples from patients ready to receive an immunotherapeutic drug. Both studies identified certain bacterial species present in more significant numbers in patients who responded positively to the drug.

 

There is still much to learn about the microbiome’s effect on cancer progression before treatment strategies can be developed. Some clinical trials are already taking place even though the microbiome’s mode of action on cancer is still largely unknown.  The following are a few proposed  microbiota-oriented interventions that could improve immunotherapy treatment:

  1. Fecal microbiota transplant from patients that have responded to immunotherapy
  2. Prebiotics and diet to promote the growth of beneficial bacteria or starve detrimental bacteria
  3. Antibiotics that destroy detrimental bacteria
  4. Probiotics that contain beneficial bacterial
  5. Drugs based on bacterial metabolic products that improve anti-tumor immunity or lessen the detrimental effects of chemotherapeutics.

Regarding the featured image courtesy of the National Institutes of Health:

The Common Fund’s Human Microbiome Project (HMP) developed research resources to enable the study of the microbial communities that live in and on our bodies and the roles they play in human health and disease. HMP has now transitioned from Common Fund support.

References

  1. Williams, Shawna. “This is your Microbiome on Drugs.” The Scientist, July/August 2019, pp. 38-45. . https://www.the-scientist.com/features/how-the-microbiome-influences-drug-action-66081
  2. Xavier, J. et al. “The Cancer Microbiome: Distinguishing Direct and Indirect Effects Requires a Systemic View.” Trends in Cancer, March 2020, vol. 6, no. 3 https://www.cell.com/action/showPdf?pii=S2405-8033%2820%2930017-0

Fessler, Jessica, et al. “Exploring the Emerging Role of the Microbiome in Cancer Immunology.” Journal for Immunotherapy of Cancer.   https://doi.org/10.1186/s40425-019-0574-4

Bispecific Antibodies for Cancer Treatment

Bispecific antibodies are bioengineered proteins that can simultaneously bind to two different types of antigen (such as found on cancer cells). Bispecific antibodies appear to be destined to play an important role in immunotherapy-based cancer therapy together with checkpoint inhibitors, CAR-T cell therapy, and other types of immunotherapy. Cancer immunotherapy improves the functioning of the immune system to better seek out and destroy cancer cells. Research has uncovered ways to modify immune cells in ways to improve their functioning.

Bispecific antibodies have an advantage over other immunotherapies since they can bring cancer cells and immune cells in closer proximity, allowing immune cells greater opportunity to kill cancer cells. Bispecific antibodies can bind to antigens that are expressed relatively weakly, making them more toxic to cancer cells than other immunotherapies. Also, bispecific antibodies can be mass produced in advance, while CAR-T cells, for example, must be prepared for each cancer patient.

The basic structure of all antibody molecules consists of four protein chains shaped like a capital letter Y. Two chains are longer and are designated “heavy,” while the other two chains are shorter and designated “light.”  Antigen-binding sites are located on the outward tips of the four protein chains. Different regions of the antibody, designated “Fc” and “Fab,” can also serve as binding sites. These regions have significance in the development of bispecific antibodies.

Public Domain (work of the US Government-May 6, 2007)

The bispecific antibody, blinatumomab, was approved by the FDA in 2017 for the treatment of acute lymphoblastic anemia. Another bispecific antibody, catumaxomab, has orphan drug status from the FDA for gastric and ovarian cancers. However, this drug is no longer produced by the manufacturer. Clinical trials are currently underway, studying over fifty bispecific antibodies for various malignancies.

References

  1. Clift,I, “Bispecific, Multispecific Antibodies Grapple with Cancer,” Genetic Engineering & Biotechnology News. Feb. 7, 2019. https://www.genengnews.com/insights/bispecific-multispecific-antibodies-grapple-with-cancer/
  2. Jenks, Susan. “Bispecific Antibodies in Cancer.” Cancer Therapy Advisor. Aug. 22,2018. https://www.cancertherapyadvisor.com/home/cancer-topics/general-oncology/bispecific-antibodies-in-cancer/
  3. Kaiser, Jocelyn. “Designer antibodies fight cancer by tethering immune cells to tumor cells.” Science. May 28, 2020. https://www.sciencemag.org/news/2020/05/designer-antibodies-fight-cancer-tethering-immune-cells-tumor-cells
  4. Runcie, K., et al. “Bi-specific and tri-specific antibodies- the next big thing in solid tumor therapeutics.” Molecular Medicine. (2018) 24:50 https://pubmed.ncbi.nlm.nih.gov/30249178/
  5. “Bispecific monoclonal antibody.” https://en.wikipedia.org/wiki/Bispecific_monoclonal_antibody

 

CRISPR Illustration

Using CRISPR in cancer research and treatment

CRISPR is a gene editing tool that works by precisely removing short segments of DNA from genes. CRISPR technology has attracted interest from the cancer research community since cancer is a genetic disease.

CRISPR consists of two components: an RNA targeting device called guide RNA, and an enzyme, commonly Cas9. The precise location of the problematic DNA sequence of a gene is determined. The guide RNA is complementary in sequence to a target DNA of a gene and binds to it.  Cas9 then cuts the DNA at this location. This process is known as “knock-out” or removal of a gene. The cell’s normal DNA repair mechanism fixes the cut by joining the two cut sections of DNA. It is also possible to “knock-in” or insert a gene between the two DNA segments.

CRISPR has been used in studies to improve immunotherapy, harnessing the body’s defense mechanism to treat cancer. In particular, CRISPR has been shown to enhance the effectiveness of CAR-T therapy. T cells are an essential component of the immune system and can interact with cancer cells through receptors. Cancer cells can develop the ability to activate or disable receptors resulting in a loss of immune function.

Studies have been conducted using CRISPR to disable CTLA-4, PD-1, and other receptors that inhibit immune function. Although CRISPR could theoretically be used to “knock-in” genes that could activate receptors to attack cancer cells, this approach has been more challenging.

References

  1. Liu, J. et al. “ Building Potent Chimeric Antigen Receptor T Cells With CRISPR Genome Editing.” Frontiers in Immunology. March 19, 2019. https://www.frontiersin.org/articles/10.3389/fimmu.2019.00456/full
  2. National Cancer Institute. “How CRISPR Is Changing Cancer Research and Treatment.” July 27, 2020. https://www.cancer.gov/news-events/cancer-currents-blog/2020/crispr-cancer-research-treatment?cid=eb_govdel
  3. Stadtmauer, E., et al. “CRISPR-engineered T cells in patients with refractory cancer.” Science 367, 1001 (2020). https://science.sciencemag.org/content/sci/367/6481/eaba7365.full.pdf

Targeting cancer’s master regulators

Cancer is caused by genetic mutations. Although targeted therapy seeks to control cancer by targeting the proteins created by the genes, the vast number of mutated genes present in cancers could necessitate the development of thousands of drugs to effectively control all cancers.

Andrea Califano, a systems biologist at Columbia University has developed a new approach to the problem of cancer gene mutations. Drawing on his computer training, Andrea developed an algorithm to analyze the vast malfunctioning cancer gene networks. He was then able to identify specific transcription factors that act as bottlenecks in the cancer gene networks. Califano has called transcription factors as “master regulators.” Transcription factors are proteins that bind to DNA to activate transcription to proteins (aberrant proteins in the case of cancers). Targeting these transcription factors can minimize the number of drugs necessary to treat cancer.

Transcription factors have had the reputation of being hard to target and therefore undruggable, but recent advances have changed the situation. Califano, through his company, DarwinHealth, has begun a clinical trial at Columbia to test drugs involving 3000 patients. DarwinHealth is also licensing their tools to other researchers around the world to test against cancer.

References

  1. Jin Jing, et al. “Identification of Genetic Mutations in Cancer: Challenge and Opportunity in the New Era of Targeted Therapy,” Frontiers in Oncology, 16 April 2019 https://www.altmetric.com/details/60056433
  2. Khamsi, Roxanne. “Computing cancer’s weak spots.” Science 12 Jun 2020. Vol. 368, Issue 6496, pp. 1174-1177. https://science.sciencemag.org/content/368/6496/1174
  3. Lambert, Melanie, et al. “Targeting Transcription Factors for Cancer Treatment.” Molecules 2018, 23 (6), 1479. https://www.ncbi.nlm.nih.gov/pubmed/29921764