Tumour-associated immunoglobulins and host cell infiltration

Abstract

Using a variety of techniques, we have investigated the possible interrelationship between tumour-associated immunoglobulins and infiltrating host cells. Initial cytological and histological studies revealed that tumour models which normally have a high immunoglobulin content also contained a relatively high proportion of host cells which could bind immunoglobulin by cytophilic processes. Rosette assays on tumour cell suspensions from mice also challenged with SRBC suggested that some of the immunoglobulin present may be non-specifically bound to host cells or synthesized in situ. Evidence that the local production of immunoglobulin could occur was obtained by protein A-PFC analysis of tumour cell suspensions. These studies also revealed that there were many more IgA-secreting cells within tumours than in spleen or lymph nodes. Finally, immunoglobulin analysis on gradient-separated tumour cell suspensions indicated that immunoglobulin was associated with both tumour and host cell-enriched (i.e., Fc-positive) fractions. These observations emphasize that much of the immunoglobulin previously noted in tumour eluates may not be associated with tumour cells as such, but may be bound to or synthesized by infiltrating host lymphoreticular cells.