Kathleen S. Mayor-Withey

Methods for derivation and detection of anti-parasite monoclonal antibodies

We describe detailed methods for derivation and cloning of myeloma hybrids which secrete antibodies specific for antigens of protozoan parasites. The methods were designed to enable the derivation of large numbers of specific monoclonal antibodies and to give high cloning efficiencies of desired hybrids. Although special attention is paid to derivation and detection of anti-parasite antibodies, the methods can be applied to many different antibody-antigen systems. Using the described methods we have isolated more than 90 myeloma hybrids which secrete antibodies specific for antigens of African trypanosomes and Theileria parasites, thus illustrating their effectiveness.

The regulation of the T-lymphocytes precursor pool by a humoral factor released by the thymus

Abstract Studies in congenitally athymic nude mice grafted with syngeneic thymus enclosed or not in a cell-impermeable Millipore chamber show that the thymus secretes one or several humoral factors controlling the size of the pool of early T-lineage cells produced by the bone marrow.

SUPPRESSOR CELLS IN TRYPANOSOMA CONGOLENSE-INFECTED MICE

Spleen cells from mice infected with T. congolense strongly suppressed lymphocyte stimulation induced in normal spleen cells by incubation with mitogens or allogeneic cells. Cell dilution studies showed that suppressor activity was extremely strong. Suppressor cell activity was markedly reduced by treatment of spleen cell populations with mitomycin-C and was unaffected by treatment with anti-Thy.1 sera and complement. Removal of cells which bound carbonyl iron or which bound to nylon columns, decreased but did not abolish suppressor activity.

Immune Depression in Trypanosoma Congolense-Infected Mice

The capacity of spleen cells from Trypanosoma congolense-infected mice to respond to the mitogens concanavalin A and bacterial lipopolysaccharide and to allogeneic lymphocytes is severely depressed or abolished. Moreover these cells cannot serve as stimulators of DNA synthesis in mixed lymphocyte reactions. The lack of responsiveness or of stimulation cannot be attributed to the dilution of appropriate B or T lymphocytes by the large number of “null” cells found in the spleen of infected mice. These “null” cells bear approximately ten times more H-2 antigen than normal lymphocytes but are devoid of Ia antigen.