METHOD FOR PRODUCTION OF ANTISERUM AGAINST GRANULA FRACTION FROM ENDOCRINOLOGICALLY ACTIVE CELLS

Abstract: Method of manufacturing antiserum against a peptide or protein component from endocrinally active cells for the identification of such cells by applying the antiserum to microscopic sections. Tissue with said endocrinally active cells is disintegrated, and from the disintegrated product an insoluble granule fraction including said peptide or protein component, is separated in a manner known per se by centrifugation and filtration steps. The insoluble granule fraction is suspended in a water solution, and the antiserum is manufactured by using the water suspension. The invention relates particularly to antisera against a granule fraction from tumours, particularly substance P producing carcinoid.

Description: Method for production of antiserum against granula fraction from endocrinologically active cells. The invention relates to a method for manufac- turing a substance for identifying predetermined endocrinally active cells. Cells producing peptide hormones are character¬ ised by the ability thereof to synthetise and secrete different types of biologically active polypepti des , i.e. hormones. The hormones are frequently produced within specific parts of the cells, the so-called riboso es, in the form of large precursor olekules, termed prohor ones, which are stored and are trans¬ formed to the final form of the hormones in other parts of the cells, usually in specific cavities or vesicles which are separated from surrounding cytoplasm by a diaphragm. These cavities or vesicles are frequently termed granules after the appearance thereof when examined microscopically. During the transfor ation of the precursor molekules or pro¬ hormones to the final hormone a number of splitting products appear. Known prohormones which are stored in cell granules and are converted to hormones there¬ in, include proinsulin, ACTH lipotropic precursor and so-called big gastrin. In cell ganules there are in addition to structure proteins also other active proteins, e.g. enzymes, which participate in the conversion of prohormones to hormones. For the ident ficat on of endocrinally active cells in histological sections there exists a tech¬ nique established for a long time and utilising the fact that antibodies (immune globulines) against the hormones are bound to these cells. Then, the anti¬ bodies can be demonstrated by coupling to them either a fluorescent substance, e.g. fl uor escei n-isothio- cyanate, or an enzyme which can be visualised by means of suitable substances. However, for some endocrinally active cells no suitable identification methods exist since the tech- nique mentioned above cannot be applied due to the fact that it has not been possible so far to produce antibodies against the hormones which are stored in the re! ated eel 1 s. The purpose of the invention is to provide a substance which can be used for , identifying said latter type of endocrinally active cells, and for this purpose the method referred to above has obtained according to the invention the characteris¬ tics appearing from claim 1. Particularly, it is intended to isolate by the method of the invention a peptide or protein compo¬ nent from such endocrinally active cell ' s which could not be identified earlier by applying the common technique, and to produce antisera against said com- ponent, which can then be applied to microscopic histological sections in order to prove the presence of such cells in the section. The invention is illustrated below by the description of the application of the method to specific endocrinally active cells in the gastro¬ intestinal canal, appertaining to the so-called enterochro affin cell system. Since the peptide hormone producing cells in the gastro-intestinal canal are not concentrated but are diffusely scattered great difficulties are involved in isolating individual peptides from such cells. Therefore, in the illustrative application one has chosen instead the possibility of isolating the related cell components from a tumour, initiated from cells of the tumour group identified as substance P producing carei noid. The tumour cells were disintegrated by homogen- isation in a 0.3 M sucrose solution, and the homo¬ geneous product obtained was cleaned from cells, cell nuclei and other major fragments by centr i fugation at 1000 x g for twenty minutes at 0°C. The super¬ natant was passed through an array of MILLIPOR filters having decreasing pore size: 8000, 5000, 3000, 1200 and 800 nm. The filtrate, an insoluble ' fraction with a particle size less than 800 nm was then centr i fugated at 40000 x g for thirty minutes. The sediment or pellet thus obtined was dispersed in destillated water, dialysed against water for some twentyfour hours and lyophilised. The lyophilised material was then suspended in a water solution and homogenised, so as to provide a suspension consisting of soluble as well as insoluble components in the walls and contents of the granules. A number of rabbits were immunised by i ntr acutaneous in * ection of the suspension together with so- called Freund's adjuvant. After six weeks antibodies against a component in the suspension could be demonstrated by the fact that tumour cells from substance P producing carcinoids reacted at conventional immuno- hi stoche ical coloring. The antigen which in the procedure described generates the antibodies in the antiserum obtained has not been definitely identified so far. When applying the antiserum to histological sections from a normal gastro-i ntesti al canal it has been found that the antibodies can be bound to the endocrinally active cells from which substance P producing carcinoids are considered to e enate. A series of carcinoid tumours has been examined with PAP-colored antiserum manufactured as described OΛ'.PI ■ above, and it has been found that such tumours react positively with the antiserum. This does not react, however, with cells from tumours of other origin.

Claims: CLAIMS 1. Method of manufacturing an antiserum against a peptide or protein component from endocrinally active cells for the dentification of such cells by applying the antiserum to microscopic sections, c h a r a c t e r i s e d in that tissue with said endocrinally active cells is disintegrated, that an • insoluble granule fraction including said peptide or protein component emanating from the cytoplasm, and having a particle size 800 nm, is separated from the disintegrated product in a manner known per se, that the insoluble granule fraction is suspended in a water solution, and that the antiserum is manufac¬ tured by using the water suspension thus obtained. 2. Method as claimed in claim 1, c h a r a c - t e r i s e d in that the tissue which is disinte¬ grated consists of tumours from said cells. 3. Method as claimed in claim 1 or 2, c h a r a c t e r i s e d in that the sediment is dispersed in water and is lyophilised before being suspended in the water solution. 4. Method as claimed in any of claims 1 - 3, c h a r a c t e r i s e d in that the granule fraction is manufactured from tumours of the type substance P producing carcinoid.

Inventors: HAOKANSSON ROLF, THORELL JAN, HAOKANSSON, ROLF, THORELL, JAN
Applicants: MILAB MALMOE IMMUNLABORATORIUM, MILAB MALMOE IMMUNLABORATORIUM AB
Application year: 1982
Main classification: G01N33
IPC codes: A61K39, G01N33