Category: Infectious Diseases

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Cancer Cell Therapies Infectious Diseases Precision Medicine

Genetically Engineered B Cells and Their Implications on Disease Treatment

Zachary Kazaz—McMaster Integrated Science Program, Specialization in Biology 2025

Recent advancements in genome editing have facilitated major developments in both existing and new gene therapies (Hirakawa et al., 2020). The culmination of these findings became most evident on July 5th 2018, when Dr. Carl June and Professor Michel Sadelain published a seminal review article in the New England Journal of Medicine, reporting the clinical success of chimeric antigen receptor (CAR) T cell therapy against certain haematological cancers; the therapy subsequently received FDA approval for lymphoma and leukaemia treatment (June & Sadelain, 2018). T cells were modified with artificial receptors that associated the recognition of target antigens with the signalling and immunological responses of the T cell (Ellis et al., 2021). Furthermore, genome editing was successfully used to remove immune checkpoints limiting T cell functionality and improving receptor efficacy (Ellis et al., 2021). The successes of CAR T cell therapies have extended the applications of immune cell reprogramming to a population less investigated thus far — the B cell.

Adaptive immune responses are facilitated by white blood cells, or lymphocytes. There are two classes of adaptive immune response: humoral (antibody responses) and cell-mediated responses, primarily enabled by two types of lymphocytes: B-cells and T-cells, respectively (Alberts et al., 2002). Humoral adaptive immunity produces antigen-specific antibodies via B-cells that identify pathogens by binding to their expressed antigens, stimulating cell-mediated immunity by signalling T-cells, cytokines, macrophages and chemical mediators which attack and neutralize the pathogen (Johnson et al., 2018). Thus, B-cells regulate the entire adaptive immune system via general and specific mechanisms, facilitated by cytokine secretion and antigen presentation respectively (Rogers & Cannon, 2021). As a result, B-cells provide a means of modifying holistic immune responses which is a more effective immunotherapy than the sole modification of cell-mediated immunity found in current immunotherapies (e.g., T-cells).

Following the first, primary, response to a specific antigen, the responding, naive, B-cells will proliferate into a colony, differentiate into effector B-cells which produce antibodies, and following infection, will form memory B-cells which encode for and maintain the antigen-specific antibody of the pathogen encountered (Akkaya et al., 2019). This enables more rapid secondary active immune response mobilization if the same antigen exposure occurs subsequently, and can provide lifelong immune surveillance (Akkaya et al., 2019). As a result, humoral immunity facilitated by B-cells is the most capable mechanism of providing prolonged immune surveillance (Rogers & Cannon, 2021).

B-cells possess many unique characteristics that make them a promising focal point for genetic engineering in immunotherapy settings. B-cells can be easily isolated in abundance from peripheral blood, then subsequently activated, grown, and matured in culture ex-vivo (Liebig et al., 2009). It is possible to engineer these isolated B-cells to express a particular gene, mature them into effector B-cells, which produce large amounts of antibodies, and add them back to the host as a remarkably effective form of gene therapy enabling long-term immunity to disease, as seen in Figure 1 (Johnson et al., 2018). In particular, gene editing can be used to alter antigen specificity with a predetermined antibody by means that permit access to all functions of the B-cell during every stage of its life cycle (Rogers & Cannon, 2021).

Figure 1. Diagram displaying the procedure of B-cell immunotherapy in patients using host donor cells (Traxinger, 2019).

By altering the variations of modified antigen-specificity, the response of B-cells to target antigens, their subsequent production of antibodies, expansion, and formation of long-term immunity, we can introduce and evolve long-term antibody specificity to reprogram B-cells that will continue to adapt to their associated pathogens (Rogers & Cannon, 2021). This is particularly relevant, as a majority of current literature on B-cell engineering focuses on producing HIV-specific B-cells (Rogers & Cannon, 2021). The prolonged antibody expression of B-cell therapy can be used to suppress chronic viral infections such as HIV. More importantly, highly mutagenic viruses, such as HIV, are capable of evading antigen-specific antibody responses, and edited B-cells can adapt to these changes, enabling B-cells to keep pace with viral mutations (Ouyang et al., 2017). This is not possible with current therapies that use fixed antigen-specificities.

The broad array of B-cell functions open many potential immune cell gene therapies. For example, the ability of antibody production in effector B-cells allows them to be used as a long-term source for the production of therapeutic proteins in-vivo, such as bnAbs and factor IX to combat hepatitis C virus and HIV (Kuhlmann et al., 2018). Also, it is possible to create these “cellular factories” using stem cells or editing B-cells ex-vivo which can be altered with a variety of methods such as CRISPR/CAS9 and viral vectors which transport the modified gene to loci of interest (Luo et al., 2020). Moreover, naive B-cells can be modified to present antigens and suppress or prevent immune responses to particular antigens, which can be used to combat autoimmune diseases (Scott, 2011).

Interestingly, B-cell engineering offers potential as an improved means of vaccination. In May of 2019, Howell et al. published findings in Scientific Immunology showing that B-cells edited to express antibodies countering respiratory syncytial virus (RSV) produced highly effective and long-lasting protection from RSV infection in mice (Moffett et al., 2019). Such findings convey that sterilizing immunity to pathogens can be accomplished in a more effective manner than current vaccination methods are able to induce or sustain.

Though great strides have been made, moving forwards, many further steps are needed for B-cell therapies to become viable in the future. Up to now, studies have used mice, however, larger animal models more related to human immunology are required to gain more practical insights. Further, studies must be conducted long-term to assess the durability of antibody production and memory in edited B-cells (Rogers & Cannon, 2021). Additionally, novel methods of delivering B-cell therapies to patients must be developed to make B-cells commercially viable and accessible on a broad scale. Engineered B-cells should be manufactured en masse from universally matching batches of unrelated donor cells (i.e. allogeneic) instead of an exclusive therapy manfactured from a single sample of patient-related donor cells (i.e. autologous). Current studies propose using B-cells from induced pluripotent stem cells, which is currently being investigated for use in CAR T cells (French et al., 2015).

Today, genetically engineered B-cells present a great capacity as a highly effective immunotherapy for particular autoimmune disorders, cancers, chronic infectious diseases, and pathogens. Further experimentation is required to progress B-cell gene therapy to human trials, however, in the near future, we are likely to see B-cells accompany CAR T-cells as a novel immune cell therapy. In the far future, the broad and holistic applications of engineered B-cells may become the basis of future immunotherapies, vaccines, and disease treatments.

References

  1. Akkaya M, Kwak K, Pierce SK. B cell memory: Building two walls of protection against pathogens. Nature Reviews Immunology [Internet]. 2019Dec13 [cited 2022Nov29];20(4):229–38. Available from: https://www.nature.com/articles/s41577-019-0244-2
  2. Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P. Chapter 24: The Adaptive Immune System. In: Molecular Biology of the Cell [Internet]. 4th ed. New York, NY: Garland Science; 2002 [cited 2022Nov28]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK21070/
  3. Ellis GI, Sheppard NC, Riley JL. Genetic engineering of T cells for immunotherapy. Nature Reviews Genetics. 2021Feb18;22(7):427–47. French A, Yang C-T, Taylor S, Watt SM, Carpenter L. Human induced pluripotent stem cell-derived B lymphocytes express SIGM and can be generated via a hemogenic endothelium intermediate. Stem Cells and Development [Internet]. 2015May [cited 2022Dec8];24(9):1082–95. Available from: https://www.liebertpub.com/doi/10.1089/scd.2014.0318
  4. Hirakawa MP, Krishnakumar R, Timlin JA, Carney JP, Butler KS. Gene editing and CRISPR in the clinic: Current and future perspectives. Bioscience Reports [Internet]. 2020Apr9 [cited 2022Nov26];40(4). Available from: https://portlandpress.com/bioscirep/article/40/4/BSR20200127/222452/Gene-editing-and-C RISPR-in-the-clinic-current-and
  5. Johnson MJ, Laoharawee K, Lahr WS, Webber BR, Moriarity BS. Engineering of primary human B cells with CRISPR/Cas9 targeted nuclease. Scientific Reports [Internet]. 2018Aug14 [cited 2022Nov29];8(1). Available from: https://www.nature.com/articles/s41598-018-30358-0
  6. June CH, Sadelain M. Chimeric antigen receptor therapy. New England Journal of Medicine. 2018Jul5;379(1):64–73. Kuhlmann A-S, Haworth KG, Barber-Axthelm IM, Ironside C, Giese MA, Peterson CW, et al.
  7. Long-term persistence of Anti-HIV broadly neutralizing antibody-secreting hematopoietic cells in humanized mice. Molecular Therapy [Internet]. 2018Sep17 [cited 2022Dec6];27(1):164–77. Available from: https://www.sciencedirect.com/science/article/pii/S1525001618304581
  8. Liebig TM, Fiedler A, Zoghi S, Shimabukuro-Vornhagen A, von Bergwelt-Baildon MS. Generation of human CD40-activated B cells. Journal of Visualized Experiments [Internet]. 2009Oct16 [cited 2022Dec4];(32). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3164064/
  9. Luo B, Zhan Y, Luo M, Dong H, Liu J, Lin Y, et al. Engineering of α-PD-1 antibody-expressing long-lived plasma cells by CRISPR/Cas9-mediated targeted gene integration. Cell Death and Disease [Internet]. 2020Nov12 [cited 2022Dec6];11(973). Available from: https://www.nature.com/articles/s41419-020-03187-1
  10. Moffett HF, Harms CK, Fitzpatrick KS, Tooley MR, Boonyaratanakornkit J, Taylor JJ. B cells engineered to express pathogen-specific antibodies protect against infection. Science Immunology [Internet]. 2019May17 [cited 2022Dec4];4(35). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6913193/
  11. Ouyang Y, Yin Q, Li W, Li Z, Kong D, Wu Y, et al. Escape from humoral immunity is associated with treatment failure in HIV-1-infected patients receiving long-term antiretroviral therapy. Scientific Reports [Internet]. 2017Jul24 [cited 2022Dec4];7(1). Available from: https://www.nature.com/articles/s41598-017-05594-5
  12. Rogers GL, Cannon PM. Genome edited B cells: A new frontier in immune cell therapies. Molecular Therapy [Internet]. 2021Nov3 [cited 2022Nov28];29(11):3192–204. Available from: https://www.sciencedirect.com/science/article/pii/S1525001621004743
  13. Scott DW. Gene Therapy for Immunologic Tolerance: Using Bone Marrow-Derived Cells to Treat Autoimmunity and Hemophilia. Current Stem Cell Research & Therapy [Internet]. 2011Mar1 [cited 2022Dec4];6(1):38–43. Available from: https://www.ingentaconnect.com/content/ben/cscr/2011/00000006/00000001/art00006
  14. Traxinger B. Engineering B cells to bypass vaccines [Internet]. Fred Hutch Cancer Center. Taylor Lab, Vaccine and Infectious Disease Division; 2019 [cited 2022Dec14]. Available from: https://www.fredhutch.org/en/news/spotlight/2019/07/moffett_vidd_sciimmuno.html
Categories
Infectious Diseases

Polio Resurgence: Uncovering the Reasons Behind the Recent Global Outbreaks

Adan Amer—McMaster Arts & Science 2021

Despite the tremendous medical and technological advancements achieved in modern human history, only one disease has been officially eradicated from the world – smallpox (1). Nevertheless, another life-threatening disease came painstakingly close to being eliminated. Polio, or poliomyelitis, is a disease caused by the wildtype poliovirus (colloquially referred to as WPV) (2). In this case, wild type refers to the naturally occurring virus – a distinction that becomes important later. WPV is commonly transmitted through contact with contaminated feces and infection commonly occurs in children under the age of 5 (3,4). Approximately 75% of people infected with the poliovirus show no symptoms, while a little less than 25% experience mild symptoms like fatigue, fever, muscle pain, and stiffness (1,3,5). In the most severe cases, 1 in 200 become paralyzed while 2-10% of those paralyzed by polio die because it immobilizes the muscles needed for breathing (5,6).

SOURCE: Shutterstock

Across 125 endemic countries, the disease had paralyzed 350,000 children annually up until 1988 when the World Health Assembly launched the Global Polio Eradication Initiative (GPEI) (5). This vaccination program was on a mission to globally eradicate all cases of polio by raising funds to implement national immunization programs in nations that could not stop the transmission of the virus on their own (7). Two different types of vaccines were used. First, an injectable vaccine that contained the inactive form of the poliovirus (abbreviated to IPV), and an oral vaccine with a live, but weakened, form of the virus (OPV). The OPV was pivotal for preventing transmission in endemic areas with unsanitary conditions because it causes the virus to replicate in the gut and build immunity in the intestines. This then prevents it from being shed through feces into the environment (1). It’s also cheap to make and easy to administer on a community-wide level since there are no injections necessary (2). On the other hand, IPV, which builds immunity in the bloodstream and prevents the virus from causing paralysis, is useful in extremely sanitary areas like North America because children there have lower immunity to the virus (1).

SOURCE: Sebastian Meyer/WHO Iraq

For the most part, the GPEI had succeeded. WPV cases declined by over 99% since 1988, with only 175 cases reported in 2019 (5). The WHO had certified the global eradication of 2 out of the 3 wildtype strains in 2015 and 2019 (8).

So, how come polio hasn’t joined smallpox on the list of fully eradicated diseases? Well, there has been a recent and concerning phenomenon where the virus in the OPV is being transmitted from a vaccinated host to a susceptible person with no immunity to polio (6). This is a rare occurrence, about 1 in 2.5 million cases, yet it was common enough to spark outbreaks of vaccine-derived poliovirus (VDPV) in about 33 countries as of 2020 (2). More recently, wastewater studies in London and throughout the state of New York showed circulating cases of VDPV in July 2022 (5).

The problem here is two-pronged: there is not enough immunization coverage in these areas, and the vaccines being administered don’t prevent outbreaks. The WHO recommends a vaccination coverage of more than 95% against polio, yet they estimate that the coverage in the UK and US were 93% and 92% respectively (5). Some of the VDPV outbreaks occurred in areas with inadequate coverage. Unvaccinated people are at risk of having the weakened virus replicate in their gut and undergo mutations that revert it back to a harmful form (2). Second, IPVs are primarily used in these regions over OPVs after the latter was withdrawn from routine immunizations in 2016 (8). IPVs can prevent the virus from becoming paralytic in the host, but they do not prevent its transmission to those who are more susceptible (1).

Currently, researchers are at odds with each other on how to solve this health crisis. Some suggest reintroducing OPVs to all regions to increase coverage and prevent transmission (1), while others want to discontinue its use and shift towards the more resource-intensive IPV to mitigate additional VDPV infections (2,4). One silver lining is that by arriving on the cusp of another contentious vaccination topic, we’re primed to make advancements in these difficult, yet crucial conversations.

References

1. Kimball S. How polio came back to New York for the first time in decades, silently spread and left a patient paralyzed [Internet]. CNBC. [cited 2022 Nov 26]. Available from: https://www.cnbc.com/2022/10/04/how-polio-silently-spread-in-new-york-and-left-a-person-paralyzed.html

2. Sharfstein J. Polio in the U.S. | Bloomberg School of Public Health [Internet]. Johns Hopkins. 2022 [cited 2022 Nov 27]. Available from: https://publichealth.jhu.edu/2022/polio-in-the-us

3. CDC. What is Polio? [Internet]. Centers for Disease Control and Prevention. 2022 [cited 2022 Nov 27]. Available from: https://www.cdc.gov/polio/what-is-polio/index.htm

4. Duintjer Tebbens RJ, Thompson KM. Polio endgame risks and the possibility of restarting the use of oral poliovirus vaccine. Expert Rev Vaccines. 2018 Aug 9;17(8):739–51.

5. WHO. Detection of circulating vaccine derived polio virus 2 (cVDPV2) in environmental samples– the United Kingdom of Great Britain and Northern Ireland and the United States of America [Internet]. World Health Organization. 2022 [cited 2022 Nov 25]. Available from: https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON408

6. PAHO. The history of Polio – from eradication to re-emergence [Internet]. Pan American Health Organization. [cited 2022 Nov 27]. Available from: https://www.paho.org/en/stories/history-polio-eradication-re-emergence

7. Thompson KM, Kalkowska DA. Reflections on Modeling Poliovirus Transmission and the Polio Eradication Endgame. Risk Anal. 2021 Feb;41(2):229–47.

8. WHO. Standard operating procedures: responding to a poliovirus event or outbreak, version 4 [Internet]. World Health Organization. [cited 2022 Nov 26]. Available from: https://www.who.int/publications-detail-redirect/9789240049154

Categories
Infectious Diseases

Does the Smallpox Vaccine Provide Protection Against Monkeypox?

Andia Tofighbenam—McMaster Honours Life Sciences 2024

Despite the name, chickens do not give humans chickenpox. Wouldn’t it be nice if the same could be said about monkeypox?

Human monkeypox is a viral zoonotic disease (spread between humans and animals), first discovered in laboratory monkeys in 1958, at the State Serum Institute in Denmark (1). The monkeypox virus (MPXV) is a member of the orthopoxviral genus from the Poxviridae family and is spread by contact with body fluids, lesions, and respiratory droplets of an infected person or animal (2). This enveloped double-stranded DNA virus has two strains: the west African clade and the central African clade (Congo Basin). As opposed to the west African clade, the central African clade is more transmissible and severe (2). The incubation period of this virus can range from 5 to 21 days, starting with a fever, extreme headache, lack of energy (asthenia), and muscle aches (myalgia). Around 1 to 3 days following a fever, skin eruption begins on the face, hands, feet, genitals, and cornea. These rashes evolve from macules to papules, vesicles, pustules, and crusts, which eventually fall off (2).

The first identified human monkeypox case was discovered in Africa in 1970, two years after the elimination of smallpox. Although not new, the west African clade of monkeypox has recently become a global outbreak concern (2). In 2003, the United States experienced the first monkeypox outbreak outside Africa. By May 2022, several human monkeypox cases were discovered in multiple non-endemic countries (2).

SOURCE: The Lancet

Another virus that is a member of the orthopoxvirus family is smallpox. Smallpox is an acute contagious disease caused by the variola virus and was the cause of millions of deaths before its eradication in 1980 (4).  There are two types of the variola virus: variola major and variola minor, both of which are spread by exchanging body fluids and large respiratory droplets with an infected individual. Variola major is exceedingly severe and has a mortality rate of 30%, while variola minor had a mortality rate of 1%. Symptoms of this virus include fever, back pain, fatigue, and a characteristic rash consisting of bumps filled with clear fluid that later turns into pus and dries out (4). 

SOURCE: The Lancet

Although both smallpox and monkeypox have similar symptoms, smallpox is not a zoonotic disease and is more severe. With that being stated, they are both members of the orthopoxvirus family, have 2 strains of differing severities, are more fatal in children when compared to adults, and are spread in similar ways (6).

Due to their similarities, smallpox vaccines are effective against the monkeypox virus. There are currently two smallpox vaccines effective for monkeypox as well: IMVAMUNE and ACAM2000. IMVAMUNE is an attenuated, non-replicating orthopoxvirus vaccine (7). This live viral vaccine was licensed in September 2019 by the FDA (US Food and Drug Administration) and is 85% effective against monkeypox. ACAM2000 was FDA licensed in August 2007 and is also made of live vaccinia virus. The Centers for Disease Control and Prevention set emergency access measures allowing access to this vaccine during non-variola orthopoxvirus (monkeypox) outbreaks (7).

Although there is no current treatment specific to monkeypox, an antiviral drug that protects against smallpox can also be used against monkeypox due to their similarities (8). This drug is called Tpoxx, or Tecovirimat, and is manufactured by SIGA technologies. Although this drug may be used for monkeypox treatment, it is important to note that it is only FDA-approved for the treatment of smallpox. For this reason, a consent form must be filled out before Tecovirimat is administered to patients with monkeypox (8).

With their differences kept in mind, smallpox and monkeypox are still both members of the orthopoxvirus family. This is advantageous as certain smallpox vaccines can be used for monkeypox, given there is currently no cure for the zoonotic monkeypox virus. 

References

1. Di Giulio DB, Eckburg PB. Human monkeypox: an emerging zoonosis. The Lancet Infectious Diseases [Internet]. 2004 Jan [cited 2022 Nov 23];4(1):15–25. Available from: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(03)00856-9/fulltext

‌2. World. Monkeypox [Internet]. Who.int. World Health Organization: WHO; 2022 [cited 2022 Nov 23]. Available from: https://www.who.int/news-room/fact-sheets/detail/monkeypox?gclid=EAIaIQobChMIvtb99eLE-wIVsDizAB1K-QDnEAAYASABEgIlLPD_BwE

3. Moore, Z. S., Seward, J. F., & Lane, J. M. (2006). Smallpox. The Lancet, 367(9508), 425–435. https://doi.org/10.1016/s0140-6736(06)68143-9‌‌

4. World. Smallpox [Internet]. Who.int. World Health Organization: WHO; 2019 [cited 2022 Nov 23]. Available from: https://www.who.int/health-topics/smallpox#tab=tab_1

‌5. Geddes AM. The history of smallpox. Clinics in Dermatology [Internet]. 2006 May [cited 2022 Nov 23];24(3):152–7. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0738081X05001707

‌6. ​​Kmiec D, Kirchhoff F. Monkeypox: a new threat?. International journal of molecular sciences. 2022 Jul 17;23(14):7866. Available from: https://doi.org/10.3390/ijms23147866

7. Rizk JG, Lippi G, Henry BM, Forthal DN, Rizk Y. Prevention and Treatment of Monkeypox. Drugs [Internet]. 2022 Jun [cited 2022 Nov 23];82(9):957–63. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9244487/#CR17

‌8. ​​CDC. Patient’s Guide to Monkeypox Treatment with Tecovirimat (TPOXX) [Internet]. Centers for Disease Control and Prevention. 2022 [cited 2022 Nov 23]. Available from: https://www.cdc.gov/poxvirus/monkeypox/if-sick/treatment.html