Sa. Imam et al., GENERATION OF A MURINE MONOCLONAL-ANTIBODY TO NORMAL MAMMARY EPITHELIUM USING MICE RENDERED IMMUNE-TOLERANT TO MALIGNANT MAMMARY EPITHELIUM, The Journal of histochemistry and cytochemistry, 42(5), 1994, pp. 585-591
A monoclonal antibody (MAb) that distinguishes normal from malignant m
ammary epithelia in tissue or cell lines was generated using a procedu
re that involved immunetolerization before immunization. Immune-tolera
nce to two transformed mammary epithelial cell lines (MCF.7 and MDA.MB
.231 cell lines combined) was induced in neonatal mice within 24 hr of
birth. Successful induction of immune-tolerance was determined by an
indirect immunohistological method, testing sera from mice against the
tolerogen (i.e., the MCF.7 and MDA.MB.231 cell lines). Mice lackiag a
ntibodies in their sera against the immune-tolerogen were subsequently
immunized with an extract of normal breast epithelium. One mouse was
selected for hybridoma production based on evidence of serum antibody
that showed reactivity with normal mammary epithelial cells (MEC) but
not with invasive breast carcinoma cells, as determined by an indirect
immunohistological method. Spleen cells from the selected mouse were
fused with a mouse myeloma cell line to generate MAb. After extensive
screening, one MAb was further studied on the basis of reactivity with
normal MEC in tissue and absence of staining of malignant MEC in tiss
ue or tumorigenic MEC lines. This test of specificity of reactivity re
vealed that the antigen detected by the specific antibody was expresse
d on the apical plasma membrane of normal glandular epithelia that inc
luded breast, cervix, colon, lung, pancreas, and stomach, but not on t
heir malignant counterparts in tissue sections. The antigen recognized
by the MAb was termed luminal epithelial antigen with an apparent MW
of 92 KD (LEA.92). This study illustrates the practical usefulness of
the immune-tolerization/immunization approach in the generation of ant
ibodies with particular specificity requirements, as in the identifica
tion of an antigen that is differentially expressed in two tissues (e.
g., normal and malignant) which otherwise have a multiplicity of antig
ens in common.