Marginal metallophilic macrophages in the mouse spleen: effects of neonatal injections of MOMA-1 antibody on the humoral immune response.

To investigate the role of the marginal metallophilic macrophages in the humoral immune response, mice were injected from birth with the monoclonal antibody MOMA-1, which reacts specifically with these cells. Multiple injections led to a drastic reduction in the number of cells but not to a complete elimination of the macrophage subpopulation. In these animals the humoral immune response against a Thymus-independent (TI) type 1 antigen was not disturbed but the responses against Thymus-dependent (TD) and T1 type 2 antigens were reduced as determined by specific antibody forming cells and serum titers. The results are discussed in relation to earlier findings that in the adult situation elimination of all macrophages in the marginal zone using DMDP encapsulated liposomes led to a reduction in the response to only TI type 2 antigens.