1/ CAR-background I:
-designer proteins that redirect T-cells👉antigen on tumor cells
-4 essential components: extracellular antigen recognition domain, hinge or spacer moiety, transmembrane domain, and intracellular signaling domains
-4 generations so far and still evolving
2/ CAR-background II:
-extracellular target-binding site is most important factor👉 lock and key for target antigen
specificity
-against a well-documented target on tumor cell surface
-appropriate antigen most crucial component for CAR T-cell activity👉across cancers (selected👇)
3/ 1960:
-seminal paper by Eva and George Klein
-dissected essential basis of modern tumour immunology
-before, researchers thought all cancers carried a common antigen
-demonstrated that the immune system would only reject cancerous cells if they came from the original tumour
4/ 1961:
-Miller studied mice and discovered that the thymus actually makes lymphocytes (T-cells) and sends them out into the rest of the body where they fight infections
👉too many T-cells can cause leukemia
👉T-cells can attack the body’s own cells👉autoimmune disease
5/ 60s to 80s:
-attempts to treat hosts with adoptively transferred cells immune to tumor antigens have been unsuccessful
-bone marrow transplants were studied and improved from the 70s👉first real immunotherapy
See history of BMT in another 🧵
6/ 1982, development of methods:
-to isolate tumor and virus-reactive T-cells
-to generate sufficient numbers of poten-
tial effector cells
-human tumors express antigens, serving as targets for tumor lysis
-graft-versus-leukemia reaction after BMT
7/ 1986, breakthrough:
-Rosenberg et al. @theNCI
-ccyclophosphamide + tumor-infiltrating lymphocytes (TIL) + IL-2👉100% of mice were cured of advanced cancer
-techniques developed to isolate TIL from human tumors
👉rationale for the use of TIL in the treatment of humans
8/ 1987:
-Kuwana et al. onstructed chimeric genes composed of immunoglobulin (Ig)-derived variable regions and T-cell receptor-derived constant regions
-2 pairs of chimeric genes were inserted into an expression vector containing both Ecogpt and neo genes
9/ 1987, hematotoxicity:
-Rosenberg et al.
-IL-2 + lymphokine-activated killer (LAK) cells from autologous lymphocytes
-80% patients developed anemia that required transfusions, 1/2 showed severe thrombopenia
👉effects may result from IL-2-mediated suppression of hematopoiesis
10/ 1989:
-Gross et al. (Israel)
-chimeric receptor provides the T cell with an antibody-like specificity and is able to effectively transmit the signal for T-cell activation and execution of its effector function
11/ 90s:
-dual-edged role played by T lymphocytes (1. versus tumor, 2. versus host) spurred a search to identify beneficial & deleterious cells
-spawned donor leukocyte infusion and virus-specific T-cells
👉How to control composition of T-cell products?
12/ 1993:
-1st generation of CARs by Eshhar et al.
-designed and constructed chimeric genes composed of a single-chain Fv domain (scFv) of an antibody linked with gamma or zeta chains, the common signal-transducing subunits of the immunoglobulin receptor and the TCR
13/ 1998, costimulation:
-Prof. Sadelain et al. @MSKCancerCenter showed that introducing a co-stimulatory molecule (CD28) into engineered T-cells allowed them to persist and remain active
👉potential for new generation of CARs
14/ 2003, evidence for systemic tumors:
-Brentjens et al. showed expanding peripheral blood T cells genetically targeting CD19 antigen in presence of CD80 + IL-15
-anti-tumor activity is further enhanced by in vivo co-stimulation
-active against human chronic lymphocytic leukemia
15/ 2007:
-first clinical study with 2nd generation CD19 CAR-T cell therapy in B-cell malignancy @MSKCancerCenter
16/ 2011, CLL study:
-Porter, Levine, June et al. designed a lentiviral vector expressing a CD19 CAR, costimulation with 4-1BB, and CD3-zeta signaling
-remission ongoing 10 months after treatment
-lymphopenia & hypogammaglobulinemia as an expected chronic toxic effect
17/ 2022, follow-up CLL:
-in 2 patients
-CAR T cells detectable >10 years after infusion, with sustained remission in both patients
👉highly activated CD4+ population
👉exhibited cytotoxic characteristics along with ongoing functional activation and proliferation
18/ Until now:
2017 was the year with the first FDA approval for CD19-directed CAR T cells for relapsed, refractory acute lymphoblastic leukemia in children and young adults. Since then, others have been approved for different indications. Full list: fda.gov/vaccines-blood…
This short view can only fail to capture all aspects. CAR-T still is complex and very expensive and not accessible in most parts of the world! However, the beauty of the field is the engineering and innovation & I hope we find ways for accessible & affordable therapies!
All these works originate from amazing researchers, groups and institutions such as @theNCI@MSKCancerCenter@fredhutch@Penn and living legends eg Carl June, Michel Sadelain, Bruce Levine and many more I cannot give justice here. Forgive me, you are all idols!
Chimeric antigen receptor T cell therapy might revolutionize the management and our understanding of autoimmune diseases
An short educational thread🧵on current status and future directions
Intro:
- CAR T therapy was originally designed to fight cancer
- now showed transformative potential in treating autoimmune diseases by targeting B cells
👉key role in disease (progression)
- safety remains focus, with a milder toxicity profile emerging in autoimmune disease
B cells?
- arise in bone marrow and go to periphery
- differentiate into antibody-secreting plasma cell populations
👉short-lived plasmablasts + long-lived plasma cells
👉reside in bone marrow
- CD19, CD20, CD38, BCMA expressed at various stages
👉enable identification
The h-index is one of the most impactful and widely used metrics to assess a researcher’s productivity and citation impact.
How it started & how it's going
A thread🧵
History:
- 2005 by physicist Jorge E. Hirsch
- assess researcher’s productivity and citation impact
- argued that total citations are skewed by few highly cited papers
👉publication counts don’t account for influence of research
We will discuss later the "dilemma of quality"...
What's the h index?
- largest number h such that h articles have at least h citations each
👉if an author has 5 publications with 9, 7, 6, 2, 1 citations
👉h-index=3
👉3 publications with 3 or more citations
BUT
the author does not have 4 publications with >3 citations❗️
Elsevier is one of the largest, most hated and most influential academic publishing companies in the world.
How it started & how it's going
A thread🧵
Founding:
- 1580, family named Elzevir, led by Lodewijk Elzevir, founded original publishing house in Leiden🇳🇱
- family's printer's mark
👉tree entwined with a vine & the words Non Solus
👉Latin for "not alone"
👉symbiosis between publisher & scholar
We will see the irony later!
Early scoops:
- Elzevir was famed for its high-quality, small-format editions of scholarly works in 17th century
- famous publication of "Observationes Medicae", first illustration of chimpanzee
- notable other publications included works by Galileo Galilei and René Descartes
Today is World Chronic Myeloid Leukemia Day #WCMLD24
Time to educate, reflect and celebrate what has been achieved
A short educational thread on CML
Intro to CML:
-BCR-ABL1-positive
-classified as a myeloproliferative neoplasm
-predominantly composed of proliferating granulocytes and determined to have the Philadelphia chromosome/translocation t(9;22)(q34;q11.2)
-affects peripheral blood + bone marrow
Pathophysiology:
-fusion oncoprotein BCR-ABL1 defines CML
-90-95% have a shortened chromosome 22
👉reciprocal translocation t(9;22) (q34;q11.2)
👉Philadelphia chromosome
-oncoprotein acts as constitutively expressed defective tyrosine kinaseö
The stethoscope is the image of medicine, a commonly used tool, and its importance in the field is immeasurable.
But what is its past, present, and future?
A short thread
Can you imagine how anything got done without a stethoscope? In order to earn its place slung around the neck of a physician, it has undergone many changes and evolved with the times. Like all aspects of medicine, it has a long history and background.
So let's dive right in.
The first reference to listening to breath sounds was in the Ebbers Papyrus in 1,500 BCE, almost 4,000 years ago❗️
Some other early cases of listening to breath sounds are recorded in the Hindu Vedas 🇮🇳 from approximately 1,400-1,200 BCE.