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An Introduction to the Immune System and Vaccines
Published in Patricia G. Melloy, Viruses and Society, 2023
The cells, tissues, organs, and vessels of the immune system of the human body are physically known as the lymphatic system. Lymphatic tissue can also be found in other body systems, including the digestive system and the respiratory system. Lymph, a fluid that circulates in the body independent of blood, flows into lymph nodes (glands) that are connected by lymphatic vessels. Organs such as the spleen, thymus, and bone marrow are all networked with the lymph nodes through the lymphatic system (Ross and Pawlina 2011). Lymph nodes can filter lymph and are major sites where immune reactions take place (Cruse and Lewis 2009). The major parts of the lymphatic system are shown in Figure 2.2.
The Immune System in Cutaneous Disease: the Search for a Mouse Model of the Immunopathology of Psoriasis
Published in John P. Sundberg, Handbook of Mouse Mutations with Skin and Hair Abnormalities, 2020
Susan F. Grammer, J. Wayne Streilein
The normal host immune response consists of recognition of foreign antigens by cellular and/or humoral components of the immune system and mobilization of elaborate mechanisms to effect removal or destruction of the antigen. Antigens in tissues must first be encountered by APC, such as macrophages or dendritic cells (DC) which can “present” them in proper context to host naive lymphocytes in the draining lymph node. This is known as the afferent limb of the immune response. Lymphocytes, once specifically sensitized to antigen in the central lymphatic tissue, begin to proliferate and can then pass into the circulation, travel to sites at which antigen is localized, and elicit a local immune response. This is known as the efferent limb. Specific T lymphocytes can target cells harboring the offending antigen directly, can produce an array of substances to help other T cells, and/or can help B lymphocytes to produce specific antibody. Humoral products of these cells can also nonspecifically recruit inflammatory cells.
The Hematologic System and its Disorders
Published in Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss, Understanding Medical Terms, 2020
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss
Along with red blood cells, the bone marrow also produces white blood cells (WBCs), also called leukocytes (leuko- = white) because they lack hemoglobin and its red color. Some leukocytes, however, are formed in the lymphatic system rather than bone marrow. Leukocytes differ from erythrocytes in two major ways—they have a nucleus, and they serve mainly to defend the body from invading organisms and other substances. Leukocytes can be divided into three main types: granulocytes, monocytes, and lymphocytes. Granulocytes evolve from myeloblasts (myelo- = marrow) in the bone marrow, while lymphocytes and monocytes are formed in lymphatic tissue.
Apyrase decreases phage induction and Shiga toxin release from E. coli O157:H7 and has a protective effect during infection
Published in Gut Microbes, 2022
Ida Arvidsson, Ashmita Tontanahal, Karl Johansson, Ann-Charlotte Kristoffersson, Sára Kellnerová, Michael Berger, Ulrich Dobrindt, Diana Karpman
The number of apoptotic cells in intestinal sections from mice sacrificed on day 2 was assessed by the TUNEL assay. Apoptotic cells were observed on the luminal side of the intestine, Figure 6. Staining was also observed in lymphatic tissue both in infected and uninfected mice. The number of dying cells was quantified and is presented as the number of TUNEL-positive cells/100 000 μm2. The highest number of apoptotic cells was observed in the group infected with E. coli O157:H7 and left untreated, Figure 6a. Few TUNEL-positive cells were found in mice infected with E. coli O157:H7 and treated with apyrase (Figure 6b) and in uninfected controls that were untreated (Figure 6c) or treated with apyrase, Figure 6d. A higher number of apoptotic cells was observed in the intestines of the mice infected with E. coli O157:H7 and left untreated (median 27.6, range 10–70.6 cells/100 000 μm2) compared to mice infected and treated with apyrase (median 5.2, range 3–8.2 cells/100 000 μm2) P < 0.05, Figure 6e. The uninfected controls showed minimal TUNEL-positive cells (vehicle, median 1.1, range 0–5 cells/100 000 μm2 and apyrase-treated, median 3.6, range 1–14.8 cells/100 000 μm2).
Albucasis (936–1013), a pioneer in tonsillectomy
Published in Acta Chirurgica Belgica, 2022
Narges Tajik, Maryam Mohseni Seifabadi, Nasrin Musakazemi, Arman Zargaran
The lymphatic tissue of the pharynx is called the Waldeyer's tonsillar ring and consists of four parts: the two tonsils of the palate, the tonsils of the lingual tonsil, the adenoids (the third tonsil), and the pharyngeal bands [8]. It is quite susceptible to anaerobic infection, which is addressed in the first stage of pharmaceutical treatment. In cases that progress and show a non-response to treatment, the patient may need tonsillectomy surgery [9]. Although tonsillectomy seems to be a modern medical achievement, the history of this concept dates to antiquity. This article compares Albucasis's tonsillectomy with that of earlier and later surgeons to show the differences in both surgical methods and tools so as to help clarify the development of techniques for this surgery during the medieval era.
Mechanisms of cellular and humoral immunity through the lens of VLP-based vaccines
Published in Expert Review of Vaccines, 2022
Hunter McFall-Boegeman, Xuefei Huang
Naïve B cells reside mainly in the spleen and lymph nodes. In order to activate them, vaccines must be targeted to the lymphatic tissue. As discussed earlier, the sizes of VLPs are well situated to track to lymph nodes (Figure 1b). VLP<apos;>s fate can be further controlled by the method of administration. Cubas et al. utilized SHIV VLPs (SIV Gag + HIV SF162 Env) to test the immune responses following injections at various common injection sites[99]. VLPs were labeled with an IR dye and lymph nodes were harvested 24 hr post injection. Intraperitoneal injection showed no VLPs in the lymph nodes and the amount of VLP in the lymph nodes increased going from subcutaneous to intramuscular and finally intradermal injection. The intradermal injection had detectable VLP levels in all four lymph nodes harvested. VLP levels in the lymph node correlated positively with the IgG titers and CTL efficacy. Therefore, caution should be taken when comparing immune responses across various studies. A relatively weak immune response could be due to the choice of the injection method and the resulting fate of VLPs tracking to lymph nodes. Additionally, the injection method can skew the class of Ig elicited. Intranasal immunization using a Qß-based vaccine against influenza was the only immunization method that elicited strong local IgA titers in the lung[138].