False statement about macrophages?: (A) Can harbor mycobacteria, (B) Derived from blood monocytes, (C) Involved in type III hypersensitivity reactions, (D) Produce tumor necrosis factor and interleukins
Answer is C. Type III hypersensitivity occurs when there is an excess of antigen, leading to small immune complexes being formed that fix complement and are not cleared from the circulation. Large complexes can be cleared by macrophages but macrophages have difficulty in the disposal of small immune complexes. Macrophages are involved in type 3 hypersensitivity Reff: Anantharayan & Panikers textbook f microbiology 9th edition pg:166 www.mayoclinic.com