Monoclonal antibodies against recombinant human growth hormone as probes to study immune function.
Monoclonal antibodies were raised against human recombinant growth hormone (rhGH) and those that did not cross-react with other human recombinant proteins like prolactin (PRL), interleukin 2 (IL-2), insulin, or bovine pituitary growth hormone were selected. The selected hybridoma supernatants were studied for their ability to influence T lymphocyte proliferation when induced either by a mitogen, such as phytohemagglutinin (PHA), or by alloantigen. All supernatants inhibited proliferation. Three MAbs were then purified by several passages on antimouse IgG (or IgM)-agarose columns, and characterized. These MAbs recognized three different epitopes, as revealed by competition study, although their inhibitory effect on PHA-induced T cell proliferation was quite similar. The data demonstrate that the MAbs were not cytolytic, that they did not interfere with the PHA binding to T cell membranes, and, as revealed by FACS analysis, did not bind to the membrane. Finally, these MAbs immunoprecipitated a 44-kDa molecule from PHA-activated T cell-concentrated supernatants. These data indicate that the MAbs recognized a soluble factor that plays a central role in T cell proliferation and that is probably the immune growth hormone.
Lattuada
D
D
Department of Pharmacology, School of Medicine, University of Milan, Italy.
Casnici
C
C
Gregori
S
S
Berrini
A
A
Secchi
C
C
Franco
P
P
Marelli
O
O
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002417:Cattle; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D013006:Growth Hormone / Q000276:immunology; D019382:Human Growth Hormone / Q000276:immunology*; D006801:Humans; D007328:Insulin / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D051379:Mice; D008970:Molecular Weight; D010902:Pituitary Gland / Q000737:chemistry; D011388:Prolactin / Q000276:immunology
D000911:Antibodies, Monoclonal; D007328:Insulin; D007376:Interleukin-2; D019382:Human Growth Hormone; D011388:Prolactin; D013006:Growth Hormone