This chapter focuses on how cells are studied, and specifically examines some of their
basic properties. It discusses the unity and diversity of present-day cells in terms of
their evolution from a common ancestor. Cells share common fundamental properties that have
been conserved throughout evolution. It also investigates complex organisms which are
composed of collections of cells that function in a coordinated manner, noting different
cells specialized to perform particular tasks. The chapter highlights the fundamental
similarities between different types of cells which provide a unifying theme in cell
biology, allowing the basic principles learned from experiments with one kind of cell to be
extrapolated and generalized to other cell types. It analyzes experimental approaches used
to study cells and reviews some of the major historical developments that have led to the
current understanding of cell structure and function.
Chapter
Introduction to Cells and Cell Research
Chapter
Carbohydrate recognition in cell adhesion and signalling
This chapter describes carbohydrate recognition in cell adhesion and signalling. Some lectins that serve as receptors for specific glycans recognize foreign cell surfaces and mediate or modulate immune responses to pathogens while others bind to endogenous carbohydrates and mediate adhesion or signalling events at the cell surface. Indeed, cell adhesion and signalling are mediated by structurally diverse lectins that recognize diverse glycans. One common feature of these systems is that they often involve transient interactions between cells that are moving relative to each other. Mice lacking individual lectins of the types discussed in the chapter are viable, but suffer from developmental or immunological abnormalities. The phenotypes of these mice demonstrate the importance of lectin recognition events in the precise orchestration of cell–cell interactions in mammals.
Chapter
Methods of studying cells
This chapter looks at several methods that have been devised to culture, identify, and characterize cells and their components, which has resulted in a wealth of advances in cell biology. It discusses culturing prokaryotic and eukaryotic cells, which means growing them in artificial media in a controlled environment. It also describes flow cytometry or cell sorting as a technique for counting cells and distinguishing and isolating specific cell types in a population of several different kinds of cells. The chapter mentions microscopy, which is a technique that uses a microscope to examine objects that are too small to be seen easily with the naked eye. It focuses on cell fractionation which involves separating the cells or tissue into a number of separate fractions.
Chapter
An introduction to cellular signalling
This chapter opens with an introduction to one of the most important aspects of modern biochemistry and cell biology: cell signalling. It explores various aspects of cell signalling and the main principles and components behind the signalling mechanisms. The chapter argues that cell signalling is not only important for understanding the functioning of a normal cell but is also of vital importance for understanding the growth and activity of an aberrant cell or a cell combating adverse conditions. The chapter also examines what makes a good signal. It then investigates the different ways in which cells signal to each other and defines cell-to-cell signalling. Lastly, the chapter turns to the discovery of oncogenes, genes that cause the uncontrolled growth of cells that may lead to cancerous growths, and the discovery of cytokines, which held great hopes for a cure for a variety of diseases.
Chapter
Stem Cells
Their Potential and Their Niches
This chapter discusses the stem cell, which maintains the ability to divide and produce a copy of itself and generate progenitor cells capable of maturing into different cell types. It explains how the niche employs a variety of mechanisms of cell-to-cell communication to regulate the quiescent, proliferative, and differentiative states of the resident stem cell. It also explores columnar cells located at the base of the intestinal crypt that serve as clonogenic stem cells for the gut epithelium, which generates transit-amplifying epithelial cells that slowly differentiate as they are pushed farther up the villus. The chapter looks at mesenchymal stem cells that are found in a variety of tissues, including connective tissue, muscle, cornea, dental pulp, and bone. It covers pluripotent stem cells that can be used in regenerative medicine to rebuild tissues and to make structures called organoids.
Chapter
Introducing cells and tissues
This chapter explains that cells are the building blocks of the body. There are many different types according to characteristic size and shape. The chapter explains that some cells can be very large, for example the cells of skeletal muscle. These may extend for up to 30 cm along the length of a large muscle. Other cells are very small. The red cells of the blood are small biconcave discs with diameters in the region of 7 μm. The chapter emphasizes that the skeletal muscle fibres and red cells represent some of the striking variations in cell morphology, noting that all cells have certain characteristics which can be evident during differentiation. The structure of a typical mammalian cell is bounded by a cell membrane called the plasma membrane or plasmalemma, which is a continuous sheet that separates the watery phase inside the cell from that outside the cell.
Chapter
Characteristics of Prokaryotic and Eukaryotic Cells
This chapter explains the characteristics of prokaryotic and eukaryotic cells. It starts by looking at the diversity of cells before moving on to talk about the characteristics of the Bacteria and Archaea. Cells were first identified through the phospholipid membrane, which is common to all life. Even though all the cells in any one organism share the same genetic material in their nuclei, they are not identical as specialized cells undertake specific functions as a result of cell-specific gene expression and consequent protein production. Specialist cells come together to form organs and tissues, mediated by interactions between different cells and between cells and the extracellular matrix.
Chapter
Teaching Mammalian Cells to Make New, Useful Things
Jamie Billington, Anna Mastela, and Susan J. Rosser
This chapter clarifies why some medicines and compounds are produced in mammalian cells rather than in bacteria or yeasts. It provides examples of biologics that can be produced in mammalian cells and lists challenges associated with producing them that are unique to mammalian cells. It also describes some of the most commonly used mammalian cell types for the bioproduction of proteins and viruses. The chapter presents a workflow on how to generate a recombinant CHO cell line and compares how biopharmaceutical companies engineer a mammalian cell line. It examines how smart cells implanted into the body might be able to help treat diseases and talks about the advantages and drawbacks of producing products in whole animals rather than in cell culture.
Chapter
Characteristics of Prokaryotic and Eukaryotic Cells
This chapter explains the characteristics of prokaryotic and eukaryotic cells. It starts by looking at the diversity of cells before moving on to talk about the characteristics of the Bacteria and Archaea. Cells were first identified through the phospholipid membrane, which is common to all life. Even though all the cells in any one organism share the same genetic material in their nuclei, they are not identical as specialized cells undertake specific functions as a result of cell-specific gene expression and consequent protein production. Specialist cells come together to form organs and tissues, mediated by interactions between different cells and between cells and the extracellular matrix.
Chapter
Liver
Anne Rayner and Alberto Quaglia
This chapter studies the cells and microscopic structures found within the liver. The liver is a large, solid organ situated in the upper right quadrant of the abdomen, below and partly behind the lower rib cage, separated from the thoracic cavity by the diaphragm. At the microscopical level, the liver parenchyma consists of a main epithelial cell population (hepatocytes) arranged in cords (hepatic plates) in close contact with a network of capillary-like vascular structures (sinusoids) containing a mixture of oxygenated arterial blood and venous blood carrying nutrients from the gastrointestinal tract. Other cell components include biliary epithelial cells lining the biliary tree ducts, endothelial cells lining the sinusoids, stellate cells involved in vitamin storage and fibrogenesis, and lymphocytes and macrophages providing an immunological barrier against circulating antigens. The chapter then looks at the main types of pathology affecting the liver and biliary tract.
Chapter
Cell Renewal and Cell Death
This chapter describes several types of differentiated cells, including skin fibroblasts,
endothelial cells, smooth muscle cells, and liver cells. These resume proliferation as
required to replace cells that have been lost because of injury or cell death. The chapter
looks at adult stem cells that are used clinically in hematopoietic stem cell
transplantation. It also talks about embryonic stem cells which can be grown in the
undifferentiated state while retaining the ability to differentiate into all of the cell
types in an organism. The chapter investigates how mammals are cloned by somatic cell
nuclear transfer, in which the nucleus of an adult somatic cell is transplanted into an
enucleated egg. It highlights the key role that programmed cell death plays in both the
maintenance of adult tissues and embryonic development.
Chapter
Cell-mediated responses
This chapter considers T-cell responses that do not involve B-cells and antibodies. It begins with examining the points of resemblance of the activation of macrophages by CD4 (helper) T-cells to the activation of B-cells, then explores the CD8 (cytotoxic) T-cell response. The chapter argues that both involve the selection and expansion of clones of effector cells from a tiny number of precursors and both result in the long-term survival of a population of memory cells that ensure a more vigorous secondary response to the same pathogen. The chapter analyzes how T-cells become activated for these responses. Next, the chapter highlights a more drastic approach to kill both the virus and its host-cell with the help of cytotoxic T lymphocytes (CTLs). It also elaborates on the t-cell memory and t-cell responses at mucosal surfaces.
Chapter
The secret lives of stem cells
This chapter focuses on stem cells, which are a special type of cell capable of being highly proliferative and differentiating into a variety of cell types. Stem cell biology provides insight into many aspects of living organisms, such as embryo development, tissue repair and regeneration, cancer treatment, and ageing. Throughout embryo development, different populations of embryonic stem cells contribute to various aspects of the growing organism. In addition to their natural roles in the body, stem cells have many potential applications for research and clinical therapies. The chapter also notes that cancer stem cells may represent a sub-population of abnormally functioning stem cells.
Chapter
Plant development
This chapter explores the development of plants. It expounds on how a plant’s architecture is the result of patterns of oriented cell divisions with a combination of positional signals and intercellular communication. Moreover, the chapter discusses cytoplasmic channels interconnecting plant cells. It notes the regeneration of an isolated somatic cell, the presence of relatively rigid walls, and the absence of any cell migration as distinctive features of plant development. The chapter discusses the early stages of plant development, in which involving both asymmetric cell division and cell-cell interactions are involved in line with patterning the body plan and the specificity of the shoot and root meristems., Twhile these meristems give rise to all the organs of the plant: stems, leaves, flowers, and roots.
Chapter
T cells and the MHC
This chapter analyzes the common feature of T-cells and a special set of molecules known as major histocompatibility complex (MHC) proteins. The chapter studies the major distinction of T-cells between cytotoxic and helper cells. The T-cell receptor, or TCR, cannot be discussed without also discussing MHC molecules. The chapter then demonstrates how TCR and MHC act together in protein recognition. The chapter also emphasizes the CD1 molecules when presenting non-protein molecules, then expounds the meaning of MHC in more detail. Next, the chapter investigates how to convert an intracellular virus or other pathogen into a series of small peptides in the groove of the MHC molecules on the cell surface. These take place in the antigen-presenting cells (APCs), which may be dendritic cells (the most important for activating resting T-cells), macrophages, or B lymphocytes. The chapter then considers superantigens, γδ T-cells, and NKT-cells.
Chapter
Haemopoiesis and the bone marrow
Andrew Blann
This chapter outlines the origin and development of blood cells, which is the process of haemopoiesis. It explains that haemopoiesis is the regulated development of blood cells as they progress from being precursor stem cells in the bone marrow to fully functioning mature cells found in the blood. It also stresses the importance of learning about haemopoiesis as it is the key to understanding several pathological processes, including anaemia, autoimmunity, and leukaemia. The chapter lists the major components of bone marrow and describes the mechanisms of haemopoiesis, including the significance of growth factors. It explores the complex nature of the molecular genetics of blood cell development and the value of the analysis of bone marrow.
Chapter
The red blood cell in health and disease
Andrew Blann and Pam Holtom
This chapter illustrates the structure and function of the red cell and how it is adapted for its purpose of carrying oxygen. It considers the morphology of the cell and interrelationships between size, shape, and colour. The chapter highlights key aspects of the cell biology and molecular genetics of erythropoiesis and of haemoglobin generation. It discusses how the red cell operates in health and in disease, noting that the principal disease associated with the red blood cell is anaemia. The chapter lists the different types of haemoglobin and explains the relationship between their structure and function. It clarifies the importance of red blood cell enzymes and metabolic intermediates, including the aetiology and consequences of polycythaemia vera and erythrocytosis.
Chapter
Principles of cell signalling
This chapter talks about individual cells which carry out specific physiological roles, such as secretion or contraction. It examines how cells receive and transmit signals of various kinds in order to coordinate their activities. As the plasma membrane forms a barrier between the signalling components within the cell and the extracellular environment, the cells have evolved various signalling methods to get around this. The chapter highlights the generation of diffusible chemical signals, the expression of receptors in the plasma membrane that are able to convey the external signals across the plasma membrane, direct contact between the plasma membrane proteins of adjacent cells, direct cytoplasmic contact via gap junctions, and the use of signals generated by a cell itself at particular stages of development. Diffusible chemical signals allow cells to communicate at a distance, while direct contact between cells is particularly important in cell–cell recognition.
Chapter
The cell cycle, cell division, cell death, and cancer
This chapter looks at the eukaryotic cell cycle. This is divided into several phases: the first gap phase (G1), the DNA synthesis phase (S), the second gap phase (G2), and the mitotic or cell division phase (M). The chapter reviews progression through the phases. This depends on the synthesis of cyclin proteins specific for different phases. At the end of each phase the cyclins are destroyed by proteolysis. The cyclins are required to activate different cyclin-dependent protein kinases (Cdks) and determine which substrates a given kinase works on in each phase of the cycle. The chapter refers to the cyclin synthesis in G1, stating that it requires the receipt by the cell of a mitogenic signal from a growth factor or cytokine. After entering M phase, a further check is made to establish that all of the chromosomes are correctly placed on the mitotic spindle.
Chapter
Cell differentiation and stem cells
This chapter looks into cell differentiation and stem cells. It notes the link between gene expression and cell differentiation by addressing how referencing extracellular signals having have a key role in differentiation, as they by triggering intracellular signalling pathways that impact gene expression. Cell differentiation leads to distinguishable cell types, such as blood cells, nerve cells, and muscle cells. In addition, the chapter looks into the properties of mammalian embryonic stem cells. It mentions the degree of plasticity resulting after cell differentiation. The chapter then discusses how human stem cells cultured in vitro can also give rise to organoids that are used for drug testing and studying disease.
