A leukocyte adherence inhibition (LAI) assay of anti-tumor immunity in rats using selective radioimmunological assessment of adherence of T lymphocytes and monocytes

✍ Scribed by Dr. Toshio Morizane; Hans Olov Sjögren

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: French
• Weight: 936 KB
• Volume: 31
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910310622

✦ Synopsis

Abstract

A new, highly sensitive micro‐glass‐tube leukocyte adherence inhibition (LAI) assay has been developed to detect anti‐tumor sensitization in a rat colon carcinoma system. This technique requires fewer cells and smaller amounts of antigen preparations than the previous glass tube method. The microscopic enumeration of adherent cells is replaced by a cellular radioimmunoassay (CRIA) which utilizes antibodies binding to mononuclear cells (MNC) and ~125~I‐labelled protein A. Antigen preparations were shown to be adsorbed to glass. Precoating of glass vials with fetal calf serum or antigen preparations was shown to cause a major increase in nonspecific LAI. The new LAI technique is designed to minimize such nonspecific LAI. By applying an anti‐T‐cell monoclonal antibody (McAb), an anti‐lg antiserum and an anti‐monocyte (MC) antiserum it became possible to assess selectively the change of adherence of T cells, B cells and monocytes. The specificity of the assay was demonstrated with anti‐T‐cell and anti‐MC reagents in criss‐cross experiments using two defined antigens and different tissue extracts as test antigens. The LAI response of peripheral blood MNC was examined after the subcutaneous isografting of 1 × 10^7^ X‐irradiated DMH‐W49 colon carcinoma cells. Six days after sensitization all the rats showed an LAI response detectable with anti‐T‐cell and anti‐MC reagents, which gave considerably higher LAI indices than anti‐MNC antiserum. After the subcutaneous isografting of 1 × 10^5^ viable DMH‐W49 cells, 12 of 24 rats (50%) showed an LAI response detectable with the anti‐MNC antiserum during a 3‐week follow‐up period. On the other hand, an LAI response was detected in all the 14 tumor‐inoculated rats tested when the adherence of T lymphocytes and monocytes was assessed selectively.