Shifting Paradigms: T Cells, FlipFlops, and Reversed T Cells


You must have come across the fundamental concepts of T cell development during your immunology class. Briefly, in the thymus, T cells expressing both CD4 and CD8 coreceptors interact with MHC molecules on thymic epithelial cells to make lineage fate decisions. CD4+ cells interact with MHCII and are called T helper cells while CD8+ cells interact with MHCI and are called cytotoxic T cells. Debates over the nitty-gritty of how this selection takes place have consisted of two main theories: “Strength of Signal model” and “Kinetic Signaling model”.

The “Strength of Signal model”, as the name suggests, focuses on the strength of the signal originating from T cell receptor (TCR) – coreceptor interactions with MHC molecules. A strong CD4-TCR signal gives rise to helper lineage while a weak CD8-TCR signal gives rise to cytotoxic lineage. According to the “Kinetic Signaling model”, the lineage decisions arise from the duration of the…

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A Way Through the Crowd: Motility of macrophages in a dense microenvironment


Macrophages- the most versatile and multipurpose cells of the immune system- scavenge away pathogens and sick cells to protect us from diseases. We have previously mentionedhow macrophages also happen to be present in almost every tissue to perform this very function. Most of the immune cells continuously circulate in the blood, but in a time of need, reach the site of infection/damage as soon as possible. Have you ever imagined what would have happened if the circulating immune cells could not migrate to your fresh wound when you got hurt? It would have taken no time for the infection to get spread throughout the body. Hence, without a doubt, motility is an important aspect of immune cells. From extensive studies, we know that immune cells squeeze through vessel walls (diapedesis) and travel towards the site, attracted by chemokine gradients, a process termed chemotaxis. In most studies, an assumption has…

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New Role for Ductal Cells in Type 1 Diabetes


Despite owning the same genetic material, our cells carry out highly specialized functions and vary from each other in many phenotypic aspects. Interestingly, when in troubled times (i.e., under stressful conditions) certain cells change their characteristic protein expression and turn into something completely unexpected, to help us survive. Fasolino and group shed light on such an instance where pancreatic ductal cells express immune surface proteins that potentially help protect against T cell infiltration in Type 1 Diabetes.

Type 1 diabetes (T1D), also called juvenile diabetes is an autoimmune disease where beta cells of the pancreas are destroyed by self-reactive T cells. The loss of beta cells abrogates insulin production which makes patients suffering from T1D completely dependent on pharmaceutical insulin for the rest of their lives. Not only is that a temporary solution, but it also deteriorates one’s quality of life. Hence, attempts in understanding the mechanism of disease elaborately…

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A Song of Marrow and Microbes


Stem cells! Iron! Macrophages! Red blood cells! Butyrate! Gut microbiota!
No, we are not just blurting out random terms (stick with us till the end to read the full story). These keywords summarize a study by Zhang and colleagues that was published in Cell Stem Cell earlier this month. However, summarizing the work in a single sentence would take out the fun from this fascinating study, and also leave you scratching your head. So instead, I present to you, the song of Marrow & Microbes!

Hematopoietic Stem Cells (HSCs) are the stem cells that give rise to everything that falls under the purview of “Blood cells”. They sit at the top of the pyramid and differentiate into common myeloid progenitors (producing Red Blood cells, platelets, mast cells, and granulocytes) and lymphoid progenitors (producing B, T cells & Natural Killer cells). HSCs station in the bone marrow throughout our life, and…

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The Spoils of Epstein-Barr Virus and Its Role in Multiple Sclerosis


Picture source: iStock, Health Central

2022 is off to a great start for Science as Harvard researchers published a study that potentially solves a longstanding question: Can viral infections cause Multiple Sclerosis (MS)? According to their findings, the answer is yes, we can confidently say that Epstein-Barr Virus (EBV), a long-term suspect for causing this autoimmune disease, is indeed the primary causative agent.

In this blog article, we will talk about EBV and its ties to diseases along with discussing the results from this research, and end with the influence of this research in the future of MS therapeutics.

On Epstein-Barr Virus

The elusive virus in question, Epstein-Barr Virus has been under scientists’ lens since its discovery in 1964. It is a type of herpes virus (Humangammaherpesvirus4) and its infections are rampant among us– up to 95% of humans are infected by EBV at some point…

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Goodnight, Sleep tight, don’t take your immunity light!


“Early to bed and early to rise makes one healthy, wealthy and wise.”

Day and night have existed for as long as the earth and sun- since before the beginning of life forms. So, it is not surprising that a large number of organisms, including all eukaryotes, have evolved considering day and night cycles. These changes that happen at physical, mental, behavioral, and molecular levels are referred to as circadian rhythms. Scientists have studied circadian rhythms for decades, and recently, Jeffrey C. Hall, Michael Rosbash, and Michael W. Young, who uncovered major genes responsible for circadian rhythms, were awarded the Nobel Prize. Common examples of the effects of circadian rhythm include body temperature, wakefulness, sleepiness, and hormonal activity.

The central circadian proteins include BMAL1 (Brain and Muscle ARNT-Like 1) and CLOCK (Circadian Locomotor Output Cycles Kaput), which are present in all mammalian cells and help in keeping track of…

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The COVID-19 Research Rundown


The grim COVID-19 pandemic shows no sign of stopping, with the Delta variant bringing new waves of infections across the world. Thankfully, the vaccination efforts are running on full throttle leading to rarer cases of adverse effects, at least amongst the vaccinated crowds (1). And now that the Pfizer mRNA vaccine has been approved by the FDA, there are not many excuses left to not be vaccinated.

On the other hand, scientists continue to extensively research meticulous aspects of the virus, revealing discoveries that are relevant to biologists and/or the public. Here, we have compiled a rundown of recent COVID19 news & research articles.

Delta & its superpower

The Delta Variant has dominated the COVID cases across the world and is still spreading rapidly. Its mutations make it 40% more efficient than the alpha variant and various studies may have figured out the secret in the change of functions that…

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New Role of Macrophages Concerning Ischemic Injuries Discovered


Blood vessels, like roads, connect all parts of our body to the heart. Through those well enclosed walls, blood circulates to every crevice to deliver oxygen and nutrients vital for survival of tissues. The heart pumps blood into the aorta that branches out into arteries that in turn further branch into capillaries, together fulfilling the task of keeping the tissues and organs well nourished. But what would happen if these blood vessels got damaged or blocked? The oxygen and nutrient supply would get hindered and tissues may start dying of starvation. This inadequate blood supply- Ischemia- can lead to necrosis, gangrene, and regional paralysis.

“Ischemic heart diseases” may ring a bell since they are currently a major cause of death worldwide. They may be caused when the arteries of the heart do not receive enough blood, leading to deterioration of heart tissue and subsequent death. Ischemic strokes can also happen…

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A Combo offer to deal with Melanoma: Latest Development with Immune Checkpoint Inhibitors


Modern Science has experienced huge breakthroughs over the last decades, one of the major ones being the discovery of immune checkpoints and their inhibitors. The checkpoint inhibitors revolutionized the stagnant field of cancer biology and were responsible for the rise of cancer immunotherapies. Immunotherapies command the immune system to destroy tumors by using antibodies against specific immunosuppressive surface receptors. Programmed cell death protein-1 (PD-1) is one such receptor expressed on T cells that interacts with programmed cell death ligand-1 (PD-L1) present on tumor cells, which leads to inactivation and subsequent anergy (absence of normal immune response) of T cells. Cytotoxic T lymphocyte-associated protein-4 (CTLA-4) is another receptor that is constitutively expressed on regulatory T cells and enhances its role by inhibiting the functions of other T cells and antigen-presenting cells, hence helping tumor growth. Monoclonal antibody treatments targeting these protein receptors are now widely used in clinics and have helped…

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Stopping Malaria at Its Source


Author: Kevin Merchant

This generation has experienced how a novel pathogen can cause a pandemic leading to turmoil, destruction of life, and deterioration of living conditions. What about pathogens that have been in our environments for decades?Malaria, spread by mosquito bites is prevalent throughout the equatorial regions (Sub Saharan Africa, Asia, and Latin America) and also occurs in temperate zones at lower rates. Unfortunately, we have seen that global warming can shift mosquito habitats by facilitating warm and humid conditions, risking its spread and infection worldwide. Currently, about 229 million cases of Malaria occur every year, leading to ~400,000 deaths worldwide. Symptoms of Malaria include high fever, headaches, intense chills, and in serious cases, jaundice, anemia and even death.

Let us dive into the modus operandi of Malaria and how a vaccine development strategy from Tripathi and group from John Hopkins University can help to curb it.

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