Effects of immunopotentiating agents on alveolar macrophage properties

Abstract

Infectious respiratory diseases in man and in domestic animals are characterized by the presence of a large number of different microorganisms: viruses, bacterias, mycoplasmas. It is therefore necessary to stimulate non-specific defense mechanisms in the lung and especially alveolar macrophages (AM). These cells, located in the alveolar air-spaces, play a major role in the lung clearance mechanisms and exert antibacterial, antiviral and antitumoral activities. Activation of alveolar macrophages was studied in vitro with lipopolysaccharide (LPS), lymphokines or mycobacterial derivatives (MDP). Rodent alveolar macrophages were rendered cytotoxic by in vitro exposure to LPS, free MDP or liposome-encapsulated MDP derivatives. In vivo, intravenously administered liposomes containing lipophilic MDP derivatives induced cytotoxic alveolar macrophages and protected mice against the development of pulmonary metastases.

Interactions of Pseudorabies virus with swine alveolar macrophages I: virus replication

“…Alveolar macrophages (AM) are the major line of defense against infectious agents which may damage the lung [5]. Due to the multitude of activities undertaken by AM such as phagocytosis of foreign particles, antigen presentation, and release of monokines, these cells are essential for the prevention of local respiratory infection.…”

Rationale for Using Immunopotentiators in Domestic Food Animals

“…If pathogen-induced immunosuppression can be moderated by immunomodulating substances, then the prospects for domestic food animals to withstand disease should be increased. Stimulation of defense mecha nisms, especially lung immune defenses, will likely require activation of local lymphoid cells such as alveolar macrophages (Charley, 1986). Targeting of immunomodulators to the critical organs will require special delivery systems, such as encapsulation in liposomes (Fogler et al, 1980), which should be considered in the field of domestic food animal immunoenhancement.…”

Activated porcine alveolar macrophages: Are biological response modifiers the answer?

“…Numerous investigations demonstrated that macrophages are involved in immunity to viruses and bacteria (Cole, 1975;Rouse and Babiuk, 1975;Breinig et ah, 1978;Domke-Opitz et ah, 1986;Devalon et ah, 1987). Because macrophages have important in vivo roles in host immunity, many studies focused attention to alveolar macrophage function (Rothlein et al, 1981;Charley et al, 1983a,b;Rothlein and Kim, 1983;Charley, 1986;Fuentes and Pijoan, 1986;EI-Awar and Hahn, 1987;Kensinger et al, 1987).…”