Innate and Adaptive Immunity

Thus, Kim emphasize the significance of the immune response for a normal functioning of an organism and recovery from any damage and harm. Immune responses can be activated by innate and adaptive immunities in vertebrate species, with the innate immune response being the primary defense mechanism of the organism that envisions the activation of various molecules of the innate immune system produced from its cells. These molecules can be subdivided into pathogen-associated molecular patterns and damage-associated molecular patterns, activated respectively in response to different types of harm and damage (Kim). Adaptive immunity envisions mediation by B lymphocytes and T lymphocytes released by the immune system organs. Contrary to molecules working within the innate immune system and produced immediately, the adaptive immune cells need about 4-7 days to become effector cells. The previous research has already proved that there is an evident connection between the two types of immunity in peripheral organs and that innate immunological signals are highly significant for the initiation of adaptive immune responses; yet, it is still unknown whether this connection is somehow regulated by the central nervous system (Kim). Therefore, the goal of the research under consideration has been to find out “whether the brain is important for rapidly conveying signals from the innate immune system to initiate adaptive immunity” (Kim).

In order to achieve the above goal, Kim used an experimental approach and employed such methods as animals and peripheral treatment, cannulation of the hypothalamic third ventricle, injection of selected doses of TNF and WP9QY into the hypothalamic third ventricle, lentivirus, histology, denervation of epididymal fat, flow cytometry, biochemical assays, and quantitative RT-PCR. With a view to analyzing data obtained as a result of experimental methods, the authors performed a series of statistical analyses, including primarily Tukey’s post-hoc test, ANOVA, and two-tailed Student’s t-test (Kim). It should be noted that the results of all the experimental methods employed by the researchers are presented in graphs, tables, and figures in the article under consideration so that the readers can analyze the process and validate the results if necessary.

As the first step of the study, Kim infected wild-type mice selected for the study with Listeria monocytogenes, the bacteria known for causing innate and adaptive immune responses. After the infection, the concentration of TNF in the mice’s cerebrospinal fluid increased significantly after 1 day and the mediobasal hypothalamus contained TNF receptor 1 in abundance (Kim). Afterwards, the researchers wanted to find out whether systemic immunity would be somehow affected by the delivery of TNF into the mice’s brain. Thus, the mice received TNF injection into their hypothalamic third ventricles of the brain (Kim). As a result of this experiment, it was revealed that concentration of TNF in the CSF of the mice injected with TNF was similar to that noted in the mice injected with L. monocytogens; yet, the former did not impact the concentration of TNF in blood in any way (Kim). Since the researchers were primarily interested in the role of the brain and its effect on immunity, they selected a 3-day experimental timeframe and confirmed that 3-day injections of TNF did not result in the sickness of the sample. It was revealed that TNF injection did not impact the amount of macrophages in the blood or tissues of peripheral organs, but it was forecast that the number of lymphocytes might increase (Kim).

Through some other observations and tests, it was confirmed that TNF in the brain led to the increase and activation of peripheral lymphocytes. With the help of other experimental tests described in detail in the article, Kim proved that the brain played an important role in the adaptive immune system as TNF signals in the hypothalamus contributed to the initiation of adaptive immune responses. Besides, it was established that the TNF pathway in the hypothalamus was a prerequisite for the initiation of adaptive immune response to the bacterial infection. Another hypothesis tested by Kim consisted in the assumption that brain-induced lipids release may be a link between the brain, the cells of the adaptive immune system, and fat. Based on experimental tests, this hypothesis was confirmed, and it was concluded that brain-induced lipolysis linked the brain-fat axis to adaptive immunity. Besides, the relationship and significance of the lipid release induced by the brain for adaptive immunity remained independent of innate immunity (Kim). Further, the research confirmed that adaptive immune responses were induced by the release of leptin and fatty acids from adipose tissue; however, the underlying mechanism of this action remains unknown.

Overall, the analysis of the article and the research procedures shows that there are no obvious flaws and missing data since the researchers used controls and compared them with the data obtained as a result of the interventions. All selected methods and experimental tests seem to be appropriate, considering the study objectives and the fact that the researchers present the procedures and results in sufficient detail. Besides, illustrative materials and graphs significantly assist in the comprehension of the study process validating the results. The article is definitely of high quality and presents the above-mentioned findings relating to a topical issue in immunology.

Withal, the study conducted by the researchers is essential for understanding the role of the brain-fat axis in the linkage of innate and adaptive immunity in the field of immunology. Moreover, it can significantly contribute to the development of new effective strategies aimed at promoting the production of lymphocytes with a view to aiding adaptive immune responses. Hence, the study under review is among the first to prove that the brain in general and the hypothalamus in particular play a significant role in inducing responses to the innate immunological signal TNF and the brain-fat axis. Kim had proved that the brain is essential in the process of conveying an innate immunological signal to the adaptive immune response, while the brain-fat axis is crucial for linking signals from innate immune system to adaptive immune system.