Procalcitonin (PCT) is a kind of protein. Its level rises in a response to a pro-inflammatory stimulus, such as severe bacterial, fungal, and parasitic infections as well as in sepsis and multiple organ failure.

C-reactive protein (CRP) is an annular, homopentameric protein found in blood serum and plasma. It is an acute-phase protein of hepatic origin whose levels rise in response to tissue injury, infection or other inflammatory stimul

Serum amyloid A (SAA) is an acute-phase protein produced by hepatocytes principally and then secreted into serum. It is degraded primarily by proteins present in the blood, on cell surfaces, and intracellularly. Liver is the predominant site for SAA degradation. During the acute-phase, hepatocytes are stimulated by large amounts of cytokines IL-1, IL-6, and TNF-α to synthesize and release SAA.

Interferon-alpha2 (IFN-alpha2, IFN-alpha2, IFNA2) is a type I interferon. Interferon-alpha exists in 13 subtypes: IFN-α1, 2, 4, 5, 6, 7, 8, 10, 13, 14, 16, 17 and 21. IFN-α2 is primarily secreted by virus-infected cells in response to a danger signal (e.g., viral DNA or RNA) and triggers an antiviral response by binding to its receptor. IFN-α2 is the first subtype discovered and is the most widely and intensively studied.

Interferon-γ (IFN-γ) is a pro-inflammatory cytokine produced primarily by T cells activated by antigens, mitogens or cognate antigens and natural killer cells. IFN-γ has been shown to play pivotal roles in host defense mechanisms, such as resistance to viruses, certain bacteria and protozoan infections in the process of innate and adaptive immunity. IFN-γ has a strong immunomodulatory function. It enhances antigen-presenting cell function, accelerates immune complex clearance and improves phagocytosis of foreign bodies. It is an important activator inducing the expression of macrophage and class 1 major histocompatibility complex (MHC) molecule.

Monocyte Chemotactic Protein-1 (MCP-1), a member of the stem C-C subfamily (B subfamily), is a non glycosylated protein containing 76 amino acids. Its molecular weight is about 8.6 kDa. It has been discovered currently that MCP-1 can be secreted from monocytes, macrophages, fibroblasts, endothelial cells, B cells, smooth muscle cells, etc. under stimulus from PHA, LPS.PolyI-C, IL-1, IFN-Y, PDGF, EGF or certain viruses.

Tumor Necrosis Factor alpha (TNFa) is a gene on the sixth pair of human chromosomes, primarily secreted by activated macrophages and immune cells. It consists of four exons and three introns. TNF-α precursor has 233 amino acids, and the mature TNF-α is a homotrimeric transmembrane protein composed of 157 amino groups with a relative molecular weight of 17 kDa.

Interleukin-4 (IL-4) is a cytokine secreted by type II helper T cells (Th2 cells). Biologically, it stimulates the proliferation of activated B cells and T cells, as well as the differentiation of CD4+ T cells into type II helper T cells. It also plays a key role in regulating humoral and adaptive immunity.

Interleukin-6 (IL-6) is a pleiotropic cytokine produced by fibroblasts, monocytes/macrophages, T lymphocytes, B lymphocytes, epithelial cells, keratinocytes, and various tumor cells. IL-6 regulates the growth and differentiation of a wide range of cells, has the ability to modulate the immune response, acute phase response and hematopoietic function, and it is critical for the body's anti-infective immune response.

Interleukin-10 (IL-10), also known as human cytokine synthesis inhibitory factor (CSIF), is an anti-inflammatory factor with immunosuppressive or immunostimulatory functions in many cell types. It consists of 178 amino acids, and acts as a homologous dimer. IL-10 is produced by almost all leukocyte subsets, including CD8+ and CD4+ T cells (e.g., Th2), γδ-T cells, NK cells, NKT cells, B cells, dendritic cells, eosinophils, mast cells, and monocytes (e.g., microglial cells, monocytes, and macrophages) and other non-leukocyte cell populations including epithelial cells, keratinocytes, and melanoma cells, etc. where expression of IL-10 is also present.

Interleukin-12 (IL-12) is a cytokine with a wide range of biological activities. It is produced primarily by activated inflammatory cells.產生。

Interleukin-17A (IL-17A), a member of the IL-17 family, is a potent pro-inflammatory cytokine produced by activated T-helper17 (Th17) cells and some innate immune system cells. IL-17A acts on multiple cell types, where it induces the expression of cytokines, chemokines, and metalloproteinases, triggers changes in downstream signaling pathways. It plays an important role in host defense, autoimmune disease pathogenesis as well as swelling and pain, so the study of IL-17 is gradually becoming a hot spot in medical and immunological research.

Interleukin-23 (IL-23) is composed of p19 and the 40kD subunit of IL-12, and it is secreted by activated DCs. p19 is structurally similar to IL-6, G-CSF and the 35kD subunit of IL-12. It promotes the proliferation of CD45RO+ memory T cells and the production of gamma interferon.