3.Bacterial growth and death of alveolar macrophages produce powerful chemotactic factors that cause a large influx of polymorphonuclear leukocytes and monocytes from the peripheral blood.
4.There are five different types of leukocytes: three types of granulocytes (eosinophil, basophil, and neutrophil) and two types of agranulocytes (monocyte and lymphocyte).
5.For example, Leptospira interrogans, the most common cause of leptospirosis, has adhesins, which are proteins that help this bacteria attach to the host's cells - usually epithelium, monocytes, and macrophages.
6.The most common co-receptors that HIV uses are the CXCR4 co-receptor, which is found mainly on T-cells, or the CCR5 co-receptor which is found on T-cells, macrophages, monocytes, and dendritic cells.
7.If we look at a bigger sample, like say a decilitre, then around 70% of those will be lymphocytes, 30% monocytes, and just a few polymorphonuclear cells -- PMNs -- like neutrophils.
8.Next up are the monocytes, macrophages, and dendritic cells, which are phagocytic cells - they gobble up pathogens, present antigens, and release cytokines - tiny molecules that help attract other immune cells to the area.
9.Unlike granulocytes, agranulocytes do not contain granules in their cytoplasm, nor do they have multi-lobed nuclei. Agrnulocytes are characterized by the presence of a single large nucleus. The two types of agranulocytes are monocytes and lymphocytes.