Kinetics of CD8 T cell expansion and differentiation in the blood and secondary lymphoid organs during L. infantum infection of rhesus macaques.
Previously, we reported that rhesus macaques infected with L. infantum were able to contain the parasites in visceral compartments (liver and spleen), during the first weeks after inoculation. However, progression to the chronic phase of infection was associated with a relapse of the parasite load in these organs as well as with a substantial increase in parasite burden in the blood, bone marrow and lymph nodes (ref, PPATHOGENS). We examined the same animals for a longitudinal analysis of the CD8 T cell response in the blood and secondary lymphoid organs during the acute and chronic phase of L. infantum infection.
The percentage of CD8 T cells in the blood or lymph nodes did not change significantly during the course of our experiments (Fig. 1A-B). In contrast, the splenic CD8 T cell pool expanded significantly after infection, from 16.9 ± 1.8 % of the total splenocytes in naïve animals, to 44.9 ± 3.6 % at day 28 post-infection (pi); a frequency that persisted elevated at the chronic phase (day 250 pi) (Fig 1C). In absolute numbers, it represented a 4-fold increase in the size of the splenic CD8 T cell population at days 28 and 250 pi, as compared with non-infected animals (Fig. 1 D).
The majority of blood CD8 T cells presented a differentiated phenotype, even in non-infected animals, as noted by low expression of CD62L (Fig. 1E-F). Hence, effector memory (CD62L- CD45RA-) or terminally differentiated (CD62L- CD45RA+) CD8 T cells predominated in the blood, regardless of pathogen presence (Fig. 1E-F). The relative frequencies of these subsets remained relatively constant throughout the e...
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...however, in the expression of the inhibitory receptor LAG-3 in splenic CD8 T cells at days 28 and 250 pi, as compared with non-infected animals (Fig. 6A-B). In lymph nodes, we failed to detect any significant increase in the expression of the two inhibitory receptors analysed (Fig. 6C-D). Nevertheless, LAG-3 expression tended to increase progressively as the infection advanced towards the chronic phase Fig. 6C-D).
Taken together, our data suggests that chronic CD8 T cell loss of function in the spleens of rhesus macaques infected with L. infantum is related with increased expression of inhibitory receptors, particularly LAG-3. Furthermore, the functional exhaustion of splenic CD8 T cells is coincident with parasite dissemination in the organism (ref. PPATHOGENS), suggesting that effector CD8 T cells are important to contain the infection and limit parasite spread.
The immunologic events that are happening at the local level during Carlton's acute inflammatory response would be:
The B cells, T cells, Macrophage, and Antibodies are all a very large part of the immune system. There are two types of T cells, killer and helper T cells. Killer T cells find and destroy cells infected with bacteria, and helper T cells control the activity of other cells in the immune system. Then, B cells are considered the “clean up crew,” attacking any bacteria or viruses the T cell left behind. They also make antibodies, which are essential for trapping invading viruses and
Zielinski, Sarah (22 January 2010). Cracking The Code of The Human Genome. Smithsonian.com. Retrieved from www.smithsonianmag.com/science-nature/henrietta-lacks-immortal-cells-6421299/?no-ist
This Radiolab podcast talks about how the HIV/AIDS epidemic started: the ultimate patient zero story, a very recent event that still hurts and still bleeds.
In The Immortal Life of Henrietta Lacks, multiple cell research studies involving Henrietta’s cells are described. Author Rebecca Skloot writes about Henrietta Lacks’ journey through her cervical cancer and how her cells changed the lives of millions long after her death. Skloot relates the history of cell research, including those studies which were successful and those that were not so successful. It is necessary for the author to include the achievements and disturbing practices of scientists throughout this history to inform readers and focus on the way Henrietta’s cells were used. Truth always matters to readers and Henrietta’s family deserves the truth.
pestis bacteria have been so successful in infecting and causing pandemics because of their ability to escape and avoid the host’s immune system (Ke, Chen, & Yang, 2013). Once a person is bitten by infected fleas, the Y. pestis bacteria enter the bloodstream, where they are accosted by macrophages and neutrophils (Ke, Chen, & Yang, 2013). While the neutrophils can typically kill these invaders (Ke, Chen, & Yang, 2013), the macrophages are challenged by Y. pestis’s “zippering” mechanism (Ke, Chen, & Yang, 2013). When “zippering”, the bacteria’s surface ligands bind to the macrophages, which ingest the bacterial cells (Ke, Chen, & Yang, 2013). Once inside, these bacteria escape from the macrophages and then become impervious to phagocytosis by the host’s immune system (Ke, Chen, & Yang, 2013). During this time of the initial stages of infection (3-7 days), an individual suffers with flu-like symptoms, such as fatigue, a high fever, and aches (Plague,
Kopp, Elizabeth, and Medzhitov, Ruslan. “A Plague on Host Defense.” The Journal of Experimental Medicine. .
“Immune Response: MedlinePlus Medical Encyclopedia.” National Library of Medicine - National Institutes of Health. Web. 18 Dec. 2011. .
This parasite is spread through the bite of sandflies. There are three different types of infections and they each show varying degrees of severity. The cutaneous form produces mild skin ulcers, mucocutaneous produces ulcers in the mouth and nose, and the visceral form of the disease starts with skin ulcers and then fever, low red blood cell count, and an enlarged spleen and liver. The parasite is detected by a microscope and visceral can also be found by doing blood tests. 12 million people are in infected in 98 different countries and 2 million new cases are found every year. The disease also kills around 20 to 50 thousand people a year.
The lymphatic system is made up of organs and tissues, that defends the body against infectious diseases, while also returning tissue fluids to the body’s bloodstream. The lymphatic system prevents the body from disease and infection by producing white blood cells. The lymphatic system helps our immune
Updated Interim CDC Guidance for Use of Smallpox Vaccine, Cidofovir, and Vaccinia Immune Globulin (VIG) for Prevention and Treatment in the Setting of an Outbreak of Monkeypox Infections.” 25 June 2013. Center for Disease Control 20 Nov. 2014.
Seattle Education Project. (2013, November). STEP: The Immune System - An Overview, [Online]. Available: http://www.thebody.com/step/immune.html [11/12/14].
The employee who sold the monkey was infected by the water the monkey spit into his mouth. The pet shop owner got infected by a scratch he received from the monkey. When the monkey arrived to the pet shop he shared a banana with another monkey who also became infected. The employee and pet shop owner both become infected and then spread the disease by contact with others in their environment. The microorganism initially started as being contracted by contact but the mode of transmission graduates to airborne. The incubation period was at first 2-3 days but then once airborne it became 24 hours until you reached
For many years before the development of vaccines, it was known that after recovery from certain diseases some people would not become infected when exposed to it again. This course by which a person is protected from certain diseases after natural infection is termed active immunity. The person is protected since the immune system remembers the past infection and reacts quickly when it comes across the issue again. Yet, for diseases that can be life-threatening, attaining immunity in this way entails running the risk of death upon the first encounter. Even for non life-threatening diseases, a lot of infections carry a risk of grave complications after recovery and so it would be preferable to obtain immunity without taking unwarranted risks. Active immunity by way of vaccination presents a much safer alternative (Childhood Vaccinations: Understanding Vaccines, 2006).
DeVeale, B., Brummel, T., & Seroude, L. (2004). Immunity and aging: the enemy within?. Aging Cell, 3(4), 195-208.