The League of Extraordinary Celltypes

B cells are lymphocytes involved in the adaptive immune response. After maturation in the bone marrow, they patrol the lymphatic organs looking for antigens, upon the encounter of which they become activated. Activated B cells produce and release specific antibodies against the invading pathogen and what’s more, they have excellent memory: they remember the antigens of past invading pathogens so that they can activate the immune response if the same pathogen revisits the body.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Semeli Platsaki, PhD. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Neutrophils or polymorphonuclear leukocytes (PMNs) are the primary types of white blood cells in humans. They stand out with their distinct segmented nuclei and granules. They are the first responders against all infectious pathogens. As the vanguard of the innate arm of immunity, neutrophils phagocytose, destroy, and digest the pathogen cells - a process that is thought to be non-specific and straightforward. They are also important modulators of inflammation.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Eshita Paul. Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Dendritic cells are diverse professional antigen-presenting cells found all over the body, including the skin, lungs and liver. They defend the body against pathogens by presenting their antigens to T lymphocytes, initiating the defense response. They can also prevent the immune system from attacking harmless cells in the body. They not only fight pathogens, but also malignant tumor cells.

Art by Nelly Aghekyan. Set in motion by Dr Emanuele Petretto. Words by Dr Nowrin Ahmed. Coordinator: Dr Masia Maksymowicz, Series Director: Dr Radhika Patnala

Red blood cells (RBCs) are also known as erythrocytes. They derive their name from a glycoprotein erythropoietin (EPO) secreted by the kidney in hypoxic (low oxygen levels) conditions. The release of EPO stimulates the production of red blood cells in the bone marrow known as erythropoiesis. RBCs form nearly 99% of the cellular component of the blood. The purpose of RBCs is to transport oxygen from pulmonary capillaries to tissue capillaries.

Credit: Art by Nelli Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Suruchi Poddar. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Dental follicle cells are stem cells involved in tooth formation. By differentiating into osteoblasts or cementoblasts, they participate in the generation of all the necessary components that keep our teeth together:the cementum, the alveolar bone and the periodontal ligament. Their ability to self-renew and differentiate into different kinds of cells, including neurons, together with the possibility to be sourced ethically and non-invasively from discarded third molars, renders them excellent candidates for cell therapy and regenerative medicine.

Art by Alexandra Banbanaste. Set in motion by Dr. Emanuele Petretto. Words by Semeli Platsaki, PhD. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Ameloblasts are short-lived enamel-producing cells originating from the dental epithelium. They regulate the intricate process of amelogenesis with great precision. During enamel formation, 50% of the ameloblasts commit apoptosis; the remaining half at the end of the process, making it impossible for the body to regenerate or repair the damaged enamel of an erupted tooth. Their activity is regulated by circadian rhythm and defects in the production of healthy ameloblasts result in quantitative or qualitative defects in tooth enamel.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Eshita Paul. Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Cementoblasts are specialized cells found in the root of teeth. They play a key role in the stability and maintenance of a tooth throughout development and into adulthood.

Art by Nelli Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Suruchi Poddar. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Langerhans cells (LCs) were first discovered by Paul Langerhans who thought they looked like neurons! LCs are located at the epidermis and have dendritic arms for sensing the skin environment. By walking the line between immune tolerance and response, LCs moderate your skin’s reactions to external stimuli, making sure it doesn’t overreact.

Credit: Art by Nelli Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Semeli Platsaki. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Merkel cells are skin cells that mediate the light touch response and tactile acuity in mammals. They are concentrated in touch sensitive areas of the skin and mucosal tissues, (such as palms, fingertips, lips, soles, paw pads and mouse whiskers), and together with the low-threshold sensory neurons innervating the epidermis, serve as the mechanosensitive touch transducers of skin producing tactile discernment.

Art by Nelli Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Eshita Paul. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Melanocytes, also known as pigment cells, produce the pigment melanin which is responsible for the beautiful colors we see in skin, hair, and eyes. The word melanin is derived from the Greek word ‘melas’ meaning black. These cells not only add color to skin and eyes, but also play a crucial role in defending the skin from harmful elements in the environment such as UV radiation and germs.

Art by Nelli Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Nowrin Ahmed. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Keratinocytes are the most abundant cell type found in the outermost layer of the skin, epidermis. They are in charge of providing immediate protection against microbial infections, UV exposure and dehydration.

Art by Nelli Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Suruchi Poddar. Project Coordinator: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Our skeleton, although stone-hard, is formed by little cells known as osteocytes. These cells are present inside the fully formed bone. Their main function is sensing mechanical stress and strain on bones. They are also involved in regulating phosphate and calcium levels in the bloodstream by releasing signalling molecules that affect other bone cells.

Art by Nelli Aghekyan, Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz, Project Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Chondrocytes are the only cells present in healthy cartilage, a tissue specialized in supporting and shaping various structures within the human body.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz. Project Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Smooth muscle cells (SMCs) are the type of muscle cells essential for functions like blood flow regulation and digestion. Found in hollow organs such as the intestines and bladder, their unique ability to sustain contractions and regenerate makes them crucial in both physiology and regenerative medicine, silently maintaining our well-being.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Agnieszka Szmitkowska. Project coordination: Dr. Masia Maksymowicz. Series Director: @Radhika Patnala

Cardiomyocytes are the muscle cells that form the heart. A specialized group called pacemakers can spontaneously generate cardiac action potentials, being responsible for each heartbeat of our hearts.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz. Project Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Skeletal muscle cells are remarkable for their unique characteristics. They are cylindrical, elongated, and multi-nucleated, specifically adapted for contraction and generating movement. These cells are striated due to their regular arrangement of actin and myosin filaments, enabling powerful and precise voluntary movements under nervous system control.

Art by Sam Esquillon. Set in motion by Dr. Emanuele Petretto. Words by Dr. Agnieszka Szmitkowska. Project coordination: Dr. Masia Maksymowicz. Series Director: @Radhika Patnala

Schwann cells are pivotal in our nervous system, ensuring efficient electrical signal transmission. Acting as insulators for neural pathways, they both protect and aid in nerve regeneration, showcasing the intricate blend of biology and physics.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Agnieszka Szmitkowska. Project coordination: Dr. Masia Maksymowicz. Series Director: @Radhika Patnala

Oligodendrocytes are a crucial type of glial cell in the central nervous system responsible for forming and maintaining the myelin sheath around axons, facilitating rapid and efficient electrical signal transmission between neurons.

Art by Sam Esquillon. Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz. Project Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Microglia, sometimes called brain macrophages, act as the primary immune cells of the central nervous system. They are involved in the development, homeostasis, and activation of brain immunity.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz. Project Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Astrocytes are the most abundant glial cells in the brain, outnumbering neurons. They support neurons in proper function by providing them with nutrients, structural support and by regulating the concentration of neurotransmitters. Their name comes from the Greek word astron meaning star, due to their star-shaped appearance.

Credit: Art by Sam Esquillon. Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz. Project Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala.

Purkinje neurons are large, complex neurons in the cerebellum, crucial for motor coordination and fine-tuning movements. These cells, discovered in 1837, have elaborate dendritic trees that resemble coral reefs, enabling them to integrate a vast array of synaptic inputs. Emerging research also implicates them in cognitive functions like language and emotion.

Art by Sam Esquillon. Set in motion by Dr. Emanuele Petretto. Words by Dr. Agnieszka Szmitkowska. Project coordination: Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala

Pyramidal neurons are large, multipolar neurons found primarily in the cortex of the brain. Known for their pyramid-shaped cell bodies, they play vital roles in cognition, memory, and information processing through their extensive axonal networks.

Art by Sam Esquillon. Set in motion by Dr. Emanuele Petretto. Words by Dr. Agnieszka Szmitkowska. Project coordination: Dr. Masia Maksymowicz. Series Director: @Radhika Patnala

Rod cells (rods), are the photoreceptor cells responsible for seeing objects at night. Although they don’t recognize colors, they are good at perceiving shapes and contours.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz. Project Coordinator: Dr. Masia Maksymowicz, Series Director: Dr. Radhika Patnala

Cone cells, the color decoders in our eyes, interpret light into vibrant hues. Three types of cones, sensitive to blue, green, and red light, allow us to perceive millions of colors, making our visual experiences possible.

Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Agnieszka Szmitkowska. Project coordination: Dr. Masia Maksymowicz. Series Director: @Radhika Patnala

Vestibular hair cells are crucial mechanoreceptors located in our inner ear. Their primary function is to convert head and body movements into neural signals. Our brain interprets them, enabling us to maintain balance and spatial orientation. These cells are essential for our everyday mobility and coordination.

Credit: Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Agnieszka Szmitkowska, Series Director: Dr. Radhika Patnala.

Taste bud cells (or gustatory cells) are present inside the taste buds in the human mouth. They recognize five tastes: saltiness, sourness, bitterness, sweetness, or umami, and transmit information about them to our brains.

Credit: Art by Nelly Aghekyan. Set in motion by Dr. Emanuele Petretto. Words by Dr. Masia Maksymowicz. Series Director: Dr. Radhika Patnala