Macrophages immune response

Figure 8-7. Development routes of the principal components involved in the immune response. Macrophages, which play an important accessory role in the immune response have been omitted.

Whereas macrophages and lymphocytes play key roles in immune responses, their presence in the early inflammatory response is generally not considered to be an immune reaction. As will be seen later under Immune Responses, specific events in which the macrophages, lymphocytes, and plasma cells participate can lead to immune responses. Macrophages process and present antigens (foreign materials) to immunocompetent cells and thus are key mediators in the development of immune reactions. 

A recent example of a CA model of the immune response in AIDS is Pandley s four-cell model using interactions among macrophages (= M) containing parts of the virus on their surface, helper T cells (= H), cytotoxic T cells (= C) and the virus (= V) ([pand89], [pandQl]) ... 

NF-kB regulates both innate and adaptive immune responses ( immune defense) [2]. Understanding the function of NF-kB in the development, maintenance, and activation of cells from the immune system (including hematopoietic cells, macrophages, dendritic cells, B and T lymphocytes) has greatly benefited from the analysis of knockout mice in which individual NF-kB family members were defective. 

Innate immune response to viral infections is predominately through interferon-alpha, -beta (IFN-a and -P) induction and activation of natural killer (NK) cells. Although viral replication can induce IFN-a and -P expression, macrophages are capable of producing and secreting cytokines which also induce the production of these type I interferons (Falk 2001). Bound IFNa and p to its receptors on NK cells increases its ability to lyse virally-infected cells. 

A large number of cells are involved in the immune response and all are derived fiom the multipotential stem cells of the bone marrow. The predominant cell is the lymphocyte but monocytes-macrophages, endothelial cells, eosinophils and mast cells are also involved with certain immune responses. The two types of immunity (humoral and cell-mediated) are dependent on two distinct populations of lymphocytes, the B cells and the T cells respectively. Both the humoral and the cell-mediated systems interact to achieve an effective immune response. 

These are the eentral eells of the immune system as they are essential for activation of the other eells assoeiated with an effeetive immune response hy the secretion of peptide mediators termed eytokines. Cytokines produeed hy macrophages and monocytes are termed monokines whilst those produeed hy lymphocytes are termed lymphokines. TH eells express CD4 on their surfaee. 

Granuloma A small nodular delimited aggregation of mononuclear inflammatory cells, or such a collection of modified macrophages usually surrounded by a rim of lymphocytes. Generally denotes a chronic, cell-mediated immune response. 

Polyanionic polymers can enter into biological functions by distribution throughout the host and they behave similar to proteins, glycoproteins and polynucleotides which modulate a number of biological responses related to the host defense mechanism. These are enhanced immune responses, and activation of the reticuloendothelial system (RES) macrophages. 

Macrophage function as sensors is essential for the elimination of pathogens, and also for the regulation of the adaptive immune response and of the inflammatory response [94]. 

---