Abstract: Cellular function assay has irreplaceable significance and value for today's clinical medicine. Immunocyte function tests include in vivo and in vitro assay. The in vitro test of immune cellular function was mainly designed according to the characteristics of proliferation activity and secretion killing activity of immune cells. Specific immune cellular function tests include: 1. Lymphocyte T cell function test, including T cellular proliferation test, T cellular secretion function test, T cellular mediated cytotoxicity test and in vivo test; lymphocyte B cellular proliferation test, hemolytic plaque test, enzyme-linked immunospot assay and in vivo assay. The natural killer cellular activity assay methods include: enzyme release method, radionuclide release method, chemiluminescence method, flow cytometry method, and the like. 2. Phagocytic function test, which further includes chemotactic function detection, phagocytosis and bactericidal function assay. In addition, the detection of islet β-cellular function is an important component of the pathophysiological study of abnormal glucose metabolism. It is clear that the islet β-cellular function status plays an important role in guiding clinically effective interventions for abnormal glucose metabolism. This article will discuss the process and significance of the above-mentioned cellular function assays.
Keywords: lymphocytes, phagocytic cellular, functional assay
- Assay of lymphocyte function
What is a lymphocyte?
Lymphocytes are a type of white blood cells, which are the smallest white blood cells produced by lymphoid organs and are important cellular components of the body's immune response function. Lymphocytes are a kind of cellular line with immune recognition function. According to their migration, surface molecules and functions, lymphocytes can be divided into T lymphocytes, B lymphocytes and natural killer cells.
The results and significance of lymphocyte functional assay
Here, we describe the value of lymphocyte function assays in a disease called henoch-Schonlein purpura (HSP). HSP is the most common autoimmune response mediated systemic vasculitis in childhood. At present, its pathogenesis has not been fully elucidated. In recent years, studies have found that there are immune dysfunctions in the body of patients with HSP. Bacteria or infections and food allergies are the main causes. Cellular lymphatic function assay found that NK cells are a group of non-specific immune effector cells, which can not only directly kill viruses and target cells but also have immunoregulatory functions. Besides, NK cells can directly recognize B lymphocytes and affect the differentiation and proliferation of B lymphocytes. When the activity of NK cells is decreased, the body's inhibition of differentiation and proliferation of B lymphocytes is weakened, and the activity of B lymphocytes is increased. The body's humoral immune function leads to increased secretion of Ig. The synthetic antigen-antibody complex increases and deposits on the blood vessel wall and glomerular basement membrane, activating complement and causing damage to vascular endothelial cellular and basement membrane. At the same time, excessive secretion of inflammatory mediators, acting on small blood vessel smooth muscles, expansion of small arteries and capillaries, increased permeability, causing edema and bleeding of skin, mucous membranes and internal organs. This is the pathogenesis of HSP. In summary, children with HSP have cellular and humoral immune dysfunction in the acute phase, and peripheral blood lymphocyte function is important for the early diagnosis of this disease.
- Assay of phagocytic function
Measuring test process
It has been shown that intraperitoneal injection of sodium thioglycolate in mice stimulates aggregation of macrophages. Four days later, the mice were injected with a suspension of sheep red blood cells in the peritoneal cavity. After one hour, the peritoneal phagocytic cells were dissected and collected. The phagocytosis of sheep red blood cells was observed by staining and microscopic examination. The phagocytic function of phagocytic cells can be determined by calculating the percentage of phagocytosis or the phagocytic index.
Studies have shown that in severe liver disease, the mononuclear macrophage function in vivo, including cellular adhesion chemical tendency, phagocytic bacteria and killing effects, and the ability to release various alcohols are inhibited, may be related to the presence of inhibitors in the body. It has nothing to do with the cause of liver disease. Once the liver disease recovers, its phagocytic function is also normal. Under normal conditions or in chronic liver injury, dead Kupffer cells are supplemented by proliferating division of adjacent cells. In acute liver injury, Kupffer cells are supplemented by circulating macrophages from the myeloproliferative surface.
- Islet beta cell function assay
What is the islet β cell function?
Islet beta cell function refers to the pulse-like secretion of insulin and the ability to release or secrete insulin and stimulate other peptides caused by various stimuli. There are many methods for detecting islet beta cell function, including detection of insulin pulse-like secretion patterns and islet beta cell secretion stimulation tests (glucose stimulation test and non-glucose stimulation test). Glucose stimulation test mainly includes high glucose clamp technique, intravenous glucose tolerance test (IVGTT) combined with mathematical model analysis technology and clinically commonly used oral glucose tolerance test (OGTT), while non-sugar stimulation test mainly includes arginine test and glucagon Prime test. In addition, it is also possible to judge its function by analyzing other peptides secreted by islet β cells, such as C peptide, proinsulin, amylin, and the like. A plurality of indicators can be obtained by the above detection method, and the islet β cellfunction is quantitatively evaluated.
The choice of islet beta cell function detection methods
Islet beta cell dysfunction in the process of diabetes is multi-faceted. Insulin pulse-like secretion mode, PI level, and detection of insulin-phase secretion reaction after glucose stimulation can be performed in normal glucose tolerance populations with high risk factors for diabetes, who might be first-degree relatives of elderly individuals and diabetic patients. The insulin phase 1 secretory response of the arginine test may be abnormal after the onset of diabetes, and the glucagon test may determine the islet β cell dysfunction at a later stage.
Therefore, appropriate functional tests can be selected for the purpose of the study.
- In the normal sugar regulation stage, high glucose clamps can be used to understand the possible defects of islet β cells in high-risk populations;
- In the process of gradual decline of islet β cells, IVGTT and OGTT can be used to evaluate insulin secretion indicators early;
- After the occurrence of diabetes, the arginine test and the change of the 2-phase insulin secretion reaction of OGTT can be used as indicators to judge the severity of the disease;
- When the islet β cell function is about to fail,only the glucagon test can be used to judge the degree of exhaustion.
In summary, the selection of islet beta cell function testing methods depends on the purpose of the test and is considered in combination with the stage in which the individual is in the natural course of diabetes. If you want to find potential islet β-cell defects, especially in evaluating drug efficacy and research mechanism, you should choose methods that are more accurate and sensitive. When conducting large-scale clinical research, the method to be chosen should be convenient and reproducible. A method for detecting islet β-cell function often fails to fully reflect the function state of islet β-cell, so it is often necessary to use a combination of methods to judge comprehensively.
In the prevention and treatment of diabetes, simulating or restoring the phase secretion and pulse secretion of insulin and effectively improving insulin sensitivity will achieve good therapeutic effects. Appropriate functional tests based on the characteristics of different individuals can help to accurately evaluate the islet β-cell functional status and insulin resistance, which is of great significance for the development of individualized treatment plans and scientific judgment of prognosis from the perspective of pathophysiology.
 Liu X, Li YR, Hu LH, et al. High frequencies of HLAB27 in Chinese patients with suspected of ankylosing spondylitis [J]. Rheumatol Int, 2010, 30(10):1305-1308