Humoral and cellular immunity are the two sides of immunity turn on during parasitic infections and ideally are aimed to fight infection. However, in some cases immunity to parasites can exacerbate the disease and induce tissue injury.
Animal models have been most useful to better understand mechanisms of immunity to parasites. Athymic mice that lack T cells are unable to control several parasite infections. This clearly indicates that T cells play an important role during the development of these infections (39,40). In the introduction of this chapter, we described some general aspects of the immune response, including cellular immunity, here we will try to expand this information. There are two major types of lymphocytes that originate in the bone marrow: B lymphocytes which mature in the bone marrow and after activation they differentiate into plasma cells that secrete antibodies. The second type are known as T lymphocytes which are derived from stem cells in the bone marrow, but mature in the thymus and are further subdivided into two broad types: cytotoxic T lymphocytes (CD8+ T cells) which kill cells infected with viruses o cells that have been transformed into cancer cells, whereas the second class of T cells (CD4+ T cells) are essential in determining B cell antibody class switching and in the activation macrophages and cytotoxic T cells (22). Macrophages are cells originated in the bone marrow and they are one of the three types of phagocytes besides of dendritic cells and neutrophils. Macrophages are distributed throughout the body in different tissues and play an important role in innate immunity. Monocytes differentiate into macrophages upon migration into di...
... middle of paper ...
...s reported in the nephrotic syndrome of quartan malaria, may produce several other pathological conditions (54). Hepatomegaly and splenomegaly of malaria, trypanosomiasis and visceral leishmaniasis are all associated with increased numbers and activity of lymphocytes and macrophages in those tissues (8,53,54). Fibrosis and the enlarged liver in schistosomiasis are a pathologic consequence of granuloma formation surrounding the worm eggs, similar to a delayed type hypersensitivity reaction and can be responsible of the symptomatology in patients with pulmonary schistosomiasis (55) (see chapter 4).
Immunosuppression is also frequently found in many diseases such as malaria, Chagas’ disease and diffuse cutaneous leishmaniasis and may lead to concomitant bacterial or viral infections or Burkitt’s lymphoma which is sometimes associated with malaria (8,53,56,57).
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- The immune system is a complicated biological body system that protects us from pathogenic organisms such as bacteria, viruses and fungi which has cells that are from the hematopoietic stem cell in the bone marrow. It includes white blood cells, chemicals and proteins like complement proteins and antibodies. The system is divided into two major parts that is the innate immunity system (non-specific) and the adaptive system (specific). The innate plays a vital role in the system as it is the primary defence mechanism whilst the adaptive immune system is the second line of defence.... [tags: Scientific Research ]
1219 words (3.5 pages)
- Are you one of those adventurous animal- loving people. Well, this might change your feelings quite a bit. Some creatures look adorable and something to take home, but they’re not so adorable after all. We might even want to flee to our homes and get our catching jars, but once you feel that racing pain, you’d never want to play with these “things” again. Many parasites and creatures that roam this earth are not known to man and/or can be deadly. People may think they know all about the deadly creatures and parasites, but I am sure they do not know about Giardia Intestinailis, Taenia Solium, Leishmaniasis, and the Guinea Worm, which indeed enjoy your insides.... [tags: parasites]
806 words (2.3 pages)
- In March, my PSYC class was presented with a challenge - to identify a personal improvement goal and to address this issue using an Immunity to Change map. My lengthy list of personal struggles was quickly narrowed down to one item with focused reflection. My improvement goal was to engage in productive thoughts and behaviors that would provide better time management practices. I was initially looking to improve my behaviors at home so that it would translate into success in all areas of my life including my career.... [tags: Immunity Change Map]
2746 words (7.8 pages)
- Gaining Control of the Gene Responsible for Apoptosis When we gain control of the gene responsible for the phenomenon of apoptosis, we will be in control of aging. We are finding more evidence every day, indicating genetic links to all sorts of factors in the human being. We are just now beginning to scratch the surface of our own genetics. A landmark discover has just been unveiled: In February , the two groups charting the human genome published their results—the entire 3 billion base pair sequence.... [tags: Apoptosis Aging Genetics Essays]
1145 words (3.3 pages)
- Parasites and their Virulence Why do some parasites kill the host they depend upon while others coexist with their host. Two prime factors determine parasitic virulence: the manner in which the parasite is transmitted, and the evolutionary history of the parasite and its host. Parasites which have colonized a new host species tend to be more virulent than parasites which have coevolved with their hosts. Parasites which are transmitted horizontally tend to be more virulent than those transmitted vertically.... [tags: Papers]
2298 words (6.6 pages)
- Introduction As creatures of the light, it is natural for us to fear the dark unknown of death. However, if we only knew how prevalent death is in our lives, perhaps we would not be so afraid or disgusted by it. For it is death that keeps our body running functionally, and giving the organ systems physical definition, enabling them to work properly. The building blocks of our bodies-- cells-- are alive and constantly growing, and if they continued to do so without pause, our organ systems would become enlarged and misshapen, and we as an unified organism would die.... [tags: Cellular Biology]
1971 words (5.6 pages)
- Cancer is one of the leading causes of death worldwide and according to the WHO it accounted for approximately 7.6 million deaths in 2008 (WHO, 2011). The most prevalent forms of cancer present in the United States are breast and prostate cancer (American Cancer Society, 2011). Over the past decade anticancer drugs and cancer treatment have made inadequate progress. However today, there is a greater understanding of the molecular basis behind the formations of tumorigenesis. This knowledge combined with the molecular diversity of natural compounds such as those found in mushrooms have paved the way for the discovery of new drugs.... [tags: Medical Research]
1350 words (3.9 pages)
- Parasites have been a major problem in horses for years. It is generally agreed upon that they should be treated against and removed, but there is a growing debate on how this should be done. While some feel preventive treatment is better, others prefer the reservation of medication for infected horses. This debate stems from recent proof that parasites are becoming resistant to the medications used to treat them. While this issue may seem unimportant to many people, it is prevalent not only in equine parasites, but with other animals and even human medications.... [tags: Major Problem, Preventive Treatment, Horses]
1352 words (3.9 pages)
- Charles Darwin’s theories on evolution state that all life on earth developed gradually through natural selection over millions of years. By tracing two organism’s branching biological lineage backwards, at some point the two organisms would have been related to each other in one way or another. William McNeill contends that at a basic level that all living things behave alike and that humans are actually “macroparasites.” Well, we all know old habits are hard to change and there should be no doubt that humans and other organisms act like one another in order to continue their lives and species.... [tags: Charles Darwin, McNeill, organisms, environment]
990 words (2.8 pages)
- Soil transmitted helminthes (STHs)are group of multicellular parasites belonging to a family of nematode (worms)which are pathogenic in nature and are known to causeinfections for human when they accidentally swallow the eggs or touch infected feces of animals. They usually transmitted through contaminated soil and they are known to survive best and reproduce in the tropical and subtropical areas of the world. Important contextual determinants for human infection are poverty, lack of sanitation, and inadequate hygiene (e.g., absence of hand washing with soap after defecation and before eating, and walking barefoot.... [tags: Worms, Disease]
1338 words (3.8 pages)