Abstract This paper discusses how antibodies and antigen serve to coat a foreign cell preventing the foreign cell from binding to other cells in the body. Binding of the antibodies and antigen to a toxin molecule prevents the foreign cell from accomplishing any of the tasks that it is intended to achieve. The paper further discusses how, never the less, this process is dependent on an effector mechanism in the complement system which has specific purposes. The compliment system serves as the overall protector while the antibodies and antigen direct the response of the compliment system which in turn destroys the foreign cells.
From the Paper "The integrity of the plasma membrane is essential for cellular survival. Could the immune system utilize this fact to destroy foreign cells that have invaded the body? How might cells of the immune system disrupt membranes of foreign cells? (Two hints: virtually all cells can secrete proteins, and some proteins form pores in membranes.) Antibodies and antigen serve to coat a foreign cell, preventing the foreign cell from binding to other cells in the body. Binding of the antibodies and antigen to a toxin molecule prevents the foreign cell from accomplishing any of the tasks that it is intended to achieve. Yet, this process is dependent on an effector mechanism in the complement system, which has specific purposes. The compliment system serves as the overall protector, while the antibodies and antigen direct the response of the compliment system, which in turn destroys the foreign cells."
Abstract This paper describes what antigens are, the different classes of blood groups and the problems that arise when blood of different types are mixed together. It also explains the dangers associated with blood transfusions and how they can be overcome.
Outline
Introduction: Blood Transfusion
Antigens and Antibodies
Blood Groups and Transfusion Reactions
Overcoming Difficulties in Transfusions
Conclusion
From the Paper "The transfusion of blood is a medically important and life saving procedure. It is important in, for example, surgery involving major blood loss, various types of anaemia, and haemophilia. Usually only some components of blood are used in specific cases, such as plasma when there is a large loss of fluid, or blood clotting factors for haemophilia."
Abstract This report explains in detail the function, structure and assembly of flagella in E.coli and Salmonella, using plain language and a number of diagrams. Movement (chemotaxis) is the primary function of flagella but its design also incorporates efficient repair capability and antigenic variation. In Salmonella and E.coli the flagellar filament is a homopolymer of flagellin monomers, although other species (such as Helicobacter) build their flagella from mixtures of two types of subunit. All the properties of the functioning filament are reflected in the structure of the flagellin monomer, which has conserved and variable regions, regions targeted by chaperones and coiling enzymes and regions evolved specifically for interaction between monomers. Chemotaxis is driven by a proton motive force (as in oxidative phosphorylation) and the basal complex that converts this energy into rapid rotation of the flagellum is highly complex.
From the Paper "Many bacteria are motile and exhibit chemotaxis ? migration through the extracellular medium towards attractants (e.g. carbon sources), and away from repellents (e.g. antibiotics). The majority move using flagella ?protein structures variable in number and position (Box 1) that generate thrust by rotating like propellers. Flagella are 15nm in diameter and can be observed under light microscopy after thick metal staining or using advanced microscopy techniques such as electron microscopy. Because of the competitive advantages of chemotaxis, there has been strong selection for efficient chemotactic apparatus and flagellar efficiency. The flagellum is based in the bacterial surface layers where a complex array of proteins forms the flagellar motor. Resembling the electric rotary motor and the membrane-bound F1F0-ATPase, and powered by a proton influx across the inner membrane, this highly efficient machine is merely 30nm in diameter. Its mechanism is the subject of ongoing research."
Abstract This paper examines how affinity maturation is a response to an antibody that occurs in vivo and how it can be defined as the gradual increase of antibody affinity for the immunising antigen with time. It looks at how it is associated with an enhanced secondary (anamnestic) response, somatic hypermutation, isotype switching and memory development.
From the Paper "Somatic hypermutation leads to mutations in the rearranged V-D-J sequences of antibodies. The antibodies generated during the primary response use the germline V regions, but in secondary responses all the generated antibodies contain a higher number of V-D-J region mutations. Random changes are introduced into the heavy and light chain genes and may lead to an increase in affinity of the antibody to the antigen. These higher affinity antibodies are then selected to enter the memory cell pool. The somatic mutations occur within the germinal centre in close proximity to the FDC network. If the variants have a high affinity for the antigen they are selected to become either plasma cells or memory B cells [4]."
Abstract This paper explains that the immune system generates numerous unusual kinds of immune reactions. For example, the body annihilates eukaryotic cells having or bearing foreign cell-surface antigens. These include cancer cells, whose cell-surface antigens are distorted when a normal cell is genetically changed into a cancer cell. The antigen-bearing cell may be eaten by macrophages or killed by killer cells, which are specialized to destroy abnormal body cells. The paper examines how the immune system functions, looking at physiological processes such as cellular immunity and humoral immunity.
From the Paper "Humoral immunity is best explained as if the virus has not yet invaded a body cell, it may be surfaced by antibody molecules that may have been secreted into the body fluids by B cells. The virus-antibody is then eaten and destroyed by a phagocyte."
A discussion of current developments in organ transplantation and the importance of the major histocompatibility complex (MHC) in causing transplant rejection.
Abstract This paper examines the role of the major histocompatibility complex (MHC), B and T cell receptors, cytokines and current developments in the field of transplantation, as well as alternative approaches being tried to induce immunological tolerance. The writer describes MHC and its genes, and its function in presenting an antigenic determinant to the T-cells. The writer explains that cytokines help to mediate immunity, but how their signaling pathways are activated and how they control cell division is not yet clear. Some experimental treatments to prevent rejection of organ transplants, such as pretransplant exposure to donor MHC antigens, are also described. The paper concludes that a better understanding of the mechanisms of rejection and tolerance, and the use of gene therapy, donor bone marrow administration and pretransplant blood transfusion techniques, TLI, and ALG may allow transplantation tolerance in the future.
Outline:
Introduction
Major Histocompatibility Complex (MHC)
T-Cell Receptor (TCR) Molecules
B-cell Antigen Receptor
Cytokine Receptors
MHC in Transplantation
Conclusion
From the Paper "The Major Histocompatibility Complex (MHC) comprises a set of molecules present on cell surfaces. This complex is responsible for lymphocyte recognition and antigen presentation. By the recognition of "self" and "non-self", MHC molecules control the immune response, and are therefore, involved in transplantation rejection. Two classes of the MHC are recognized, Class I and Class II MHC molecules, which belong to the Immunoglobulin Supergene Family. T-cell receptors, immunoglobulins, CD4, CD8, and others also belong to this family."
A descriptive overview of the vertebrate adaptive immune response to both intra and extra-cellular pathogens with explicit focus on T-cell B-cell collaboration and antibody response.
Abstract This paper covers the major pathways by which foreign antigens are identified and dealt with through the adaptive immune response which is paramount on B-cell and T-cell responses and interaction with one another in distinct pathways and steps. It includes several diagrams and their explanations of antigens, B-Cells, T-Cells, APC's and more and their interactions and processes they go through.
From the Paper "All immune responses involving T-cell B-cell collaborations follow distinct pathways of interactions and development. These very pathways of the adaptive immune response are almost entirely dependant on the cellular interaction of B- cells and T- cells with one another. It is within each stage of these pathways and the progression of an adaptive immune response that we will concern ourselves. The following is a condensed synopsis of the adaptive immune response and the cellular interactions that will be the emphasis of this paper. Within secondary lymph tissues foreign antigen is presented to naive B-cells via their surface immunoglobulins (Igs) receptors. The same antigen is also presented to naive T-cells at this time. This presentation and subsequent recognition of antigen by both types of cells results in and end product of proliferation and development of naive B-cells into plasma cells whose function is the production of soluble immunoglobulins (antibodies), and the differentiation and development of memory B-cells whose function is to respond to subsequent exposure to the same antigen. However, this pathway is not self-sufficient and requires the direct interaction of activated T-cells, specifically "helper" T-cells (Th2 cells) 1,9. It is these T-cells in conjunction with the antigen presenting B-cells that interact to produce a hormonal response to infection. These interactions activate Th2 cells that in turn promote B-cell activation both through T-cell secreted cytokines, (interlukeinI1-2, 4 and 5), and also through direct cell to cell contacts involving specific surface proteins and corresponding receptors and the signaling initiated by the binding of these proteins to one another."
Abstract This paper discusses the problem of medicine's inability to induce antigen-specific immune tolerance, the final technical obstacle to bringing face transplants into widespread clinical application. The paper presents an overview of historic and current immunological research - from the use of chimerism, to the use of monoclonal antibodies to control T-cell activation - and its role in future prospects for a non-pharmaceutical strategy for tolerance induction in humans. The paper highlights studies that have examined tolerance in recipients of composite tissue allografts (CTAs), with emphasis on studies using animal models involving skin allografts, and with the intent of providing insight into the issues presented by transplantation of a face. It includes graphs and photographs to illustrate this.
Outline:
Abstract
Introduction
CTA Study Goals
Antigenicity of Facial Allograft Components
Immune Tolerance and Chimerism
T-cells: Activation and Blockage
Memory Cells: The Ghost in the Immune Machine
Conclusion
From the Paper "Investigators are exploring several strategies in an attempt to provide medicine with safe and effective pharmaceuticals and clinical protocols for inducing tolerance after transplant. These include creating and using chimerism, and developing targeted bio-engineered monoclonal antibodies to inactivate or destroy T cells. This review, in its overview of historical and current immunological research, provides insight into the development of a T-cell-based strategy from a basic understanding of chimerism. This review also highlights studies that examine tolerance in recipients of CTA transplants, with specific emphasis on those using skin allograft animal models."
Tags: medical, operation, plastic, surgery, anti-immune, system
Abstract The essay begins with a discussion of genetic and environmental risk factors for disease, and the interaction between the two. The essay then goes on to discuss the improved management of genetic disease, thanks to progress in science and technology, dividing management into prevention and treatment. The paper explains how medical professionals are seeking to treat the root of the problem through organ transplants, somatic cell therapy, vaccines, gene therapy, dietary modifications, and more.
From the Paper "The combined effects of both multiple genetic and environmental risk factors cause some diseases. Most of the risk factors are probably of small effect individually but in combination with genetic susceptibility they may cause illnesses including; diabetes, coronary heart disease, breast cancer, schizophrenia, and Alzheimer's disease. [2] A greater knowledge of the pathophysiology of such diseases is necessary and research is discovering new facts everyday but the lack of a simple relationship between genotype and phenotype makes conclusions difficult. Not everyone with a given susceptibility gene gets the disease and not everyone with the disease has a given susceptibility gene."
From the Paper " HIV Testing
The causative agent in the present acquired immune deficiency syndrome (AIDS) pandemic is the human immunodeficiency virus (HIV). HIV exists in various forms, including HIV.1 and HIV.2. A number of laboratory tests are currently available for their detection.
HIV is a complex retrovirus of the lentivirus subgroup. It contains two copies of single.stranded viral RNA (1:305). The HIV genome contains structural genes that encode the proteins of the whole virus particle as well as replicative enzymes. The retrovirus also contains at least eight additional regulatory and accessory genes that regulate its life cycle (1:306).
Within about 4 to 6 weeks of initial HIV infection there is a period of viremia without detectable antibodies (1:306)..."
Abstract This paper briefly summarizes and then reviews an article on a potential cancer therapy entitled "Exploiting T cell Receptor Genes for Cancer Immunotherapy." The paper explains that the article reviewed discussed various cancer treatment options with T cell receptor immunotherapy and then goes on to discuss the results and conclusions found in the article. The paper concludes that the article was well-written and informative.
From the Paper "Adoptive antigen-specific immunotherapy is a potential cancer therapy because immunocompetence is not required and lymphocyte specificity can be targeted against tumour-associated antigens. T cell receptor (TCR) genes isolated from antigen-specific T cells may be therapeutically used for antigen-specific immunotherapy. TCR gene therapy may provide an appealing strategy to develop antigen-specific immunotherapy. Examples of this type of therapy include retroviral TCR gene transfer, TCR gene modified lymphocytes, and TCR gene expression."
Tags: monoclonal, generic, reagents, surface, helper, functions, cytotoxicity, cytokine, production
Abstract Current researchers have approached the question of sexual preference and its causes from a biological as well as a psychological and sociological point of study. Both types of researchers would agree that the various areas of influence are not necessarily exclusive of one another, and that no single area dominates the decision as to what determines sexual orientation. The paper shows that some researchers have demonstrated a biologic or genetic component of human sexual orientation. Others dispute this claim, stating that sexuality is largely an environmentally-influenced preference. In conclusion, this paper argues that it is clearly necessary to approach the causes of sexual orientation from a point of view that includes both biologic and environmental factors.
From the Paper "Blanchard and Klassen have hypothesized that the Y-linked minor histocompatiblity antigens, or H-Y antigens, are involved in sexual development. Their study shows that some mothers experience a progressive immunization to the antigen, and that this change may increase the effects of H-Y antibodies on the sexual differentiation of the brain in male children that are born later in the birth order within a family. According to the authors, this information is consistent with the fact that there is a correlation between sexual orientation in men and the number of older brothers they have. Each older brother increases the odds of homosexual preference by nearly 33% in the younger siblings."
Abstract This paper answers a number of questions about the lymphatic system and the immune system. The paper includes technical descriptions of both systems and discusses their anatomical and physiological features.
From the Paper "The lymphatic system is a one-way system because it functions to return excess tissue fluid to the circulation. It only flows in one direction. The blood vascular system is a two-way system because it brings oxygen and nutrients to the tissues via the arteries and takes carbon dioxide and waste products away from the tissues via the veins. Lymphatic vessels resemble veins in that they have thin walls and they have valves to prevent back flow. Lymphatic capillaries differ from blood capillaries in that they begin in the..."
Tags:antigen, antibody, lumph node, lyphatic system
Abstract In this article, the writer discusses the techniques of immunohistochemistry. The writer examines how these techniques are applied to the study of neuro chemical pathways in the mammalian brain. In this article, several studies using immunohistochemical methods to study brain neuro chemistry are examined.
From the Paper "An antibody is a protein produced by lymphocytes of the immune system in response to the presence of a foreign antigen in the system. It usually binds to the foreign antigen and causes it to precipitate from the circulation. Antibodies can be purified in the laboratory and conjugated chemically bonded to a variety of substances including a fluorescent dye such as fluoresce-in. This conjugated antibody can then be applied to sections of tissue that have been lightly fixed or frozen so that the location ... "
Abstract This paper explains that the immune system has the startling ability to differentiate between your body's own cells, which is self and non self (foreign cells). It claims that each cell lugs protein markers or antigens that recognize it as self or non self. Your body's immune system, it expands, couples with all cells that hold the self marker except with specific autoimmune diseases where the body could slip up and think that it is self for non self. Basically, anything that carries a non self marker prompts a response from the immune system, which may include bacteria and viruses.
From the Paper "The body's immune system has the startling ability to differentiate between its own cells, between which are "self" and which are "non-self" (foreign cells). Each cell lugs protein markers or antigens that recognize the differences. The body's immune system couples with all cells that hold the "self" marker, except in cases of specific autoimmune diseases in which the body could slip up differentiating between the two. Any cell that carries a non-self marker prompts a response from the immune system, which may include bacteria and viruses. The immune system accumulates a large cache of cells. Some immune cells can destroy a myriad of foreign invaders, while others attack and destroy only specific targets. For the immune system to work succinctly, the immune cells must not only communicate but cooperate with each other."
