The selective suppression of immunogenicity by hyaluronic acid.

A hyaluronidase-sensitive component of human peritoneal fluid from a patient with Wilms' tumor when injected into rabbits has been shown to suppress the formation of humoral precipitating antibodies to certain major classes of proteins present in the fluid. Furthermore, it has been found that hyaluronic acid, when included with certain test antigens (serum albumin, fetuin) or antigen mixtures (tumor isolates or mixtures of albumin, immunoglobulin G and immunoglobulin M), produces a marked distortion or complete blockage of immunoelectrophoresis precipitin arcs, as well as altered gel chromatography elution profiles. These findings that hyaluronic acid can interfere profoundly with both the elicitation of a complete antibody response and the formation of "normal" patterns of antigen-antibody precipitates in laboratory tests supports the possibility that this polysaccharide may play an immuno-regulatory role by masking potential immunogens. Consideration of the mechanisms for these in vivo and in vitro effects suggests that there may be some common basis in an "excluded volume" property of the hyaluronate, but this does not appear sufficient to explain the complexity and selectivity of the observed phenomena.

Glycosaminoglycan in the blood and renal tissue of a patient with nephroblastomatosis.

Bilateral nephroblastomatosis was diagnosed in a 15-month-old white female. Prior to surgery, multiple peripheral blood smears (Wrights' stain) revealed an azurophilic staining extracellular material. When serum was added to a three percent acetic acid solution, a floccular, fibrous precipitate formed at the meniscus of the tube. Serum protein electrophoresis on cellulose acetate support media resulted in a distorted pattern which corrected to a normal pattern upon treatment with hyaluronidase. These peripheral blood abnormalities disappeared following a left nephrectomy. Quantitative chemical analysis of diseased renal tissue yielded 81 micrograms of readily extracted glycosaminoglycan (GAG) per gram of tissue. The importance of abnormal glycosaminoglycan production in patients with malignant disease is discussed both in terms of clinical importance and possible roles of cell exudates.

A fetuin-like antigen from human nephroblastoma.

An antigen was detected in pooled human nephroblastomas using antiserum prepared in rabbits against an ethylemediaminetetra acetic acid (EDTA) extract of the tumors. This antigen was not found in normal human plasma or kidney extracts, and was not related to the ABO or Forssman blood groups. The antigen was detected in extracts of cultured nephroblastoma cells, but was not present in extracts of normal human fetal kidney cell cultures. The antigen is believed to be present at the cell surface, as cell viability was not significantly lowered during the extraction procedure. A reaction of complete identity was demonstrated by Ouchterlony double diffusion experiments with this antigen and purified bovine fetuin. The antigen was not found in extracts of human fetal spleen, thymus or kidney, nor in human fetal serum. Furthermore, the antigen does not possess determinants in common with the human alpha-fetoprotein of hepatomas, nor was it detected in human renal clear cell carcinoma. Initial characterization of the antigen showed it to be nondialysable, not sedimentable at 100,000 times g for 2 h, stable to repeated freeze-thawing and to incubation at 56 degrees C for 1 h, and water soluble over a wide pH range. The antigen was susceptible to digestion with pronase and trypsin and possibly hyaluronidase, but not to ribonuclease or neuraminidase. The protein portion is therefore of major importance to the structural integrity of this antigen. The relationship between this antigen and other abnormal materials reported previously in nephroblastoma patients is being studied.

Isolation of Wilms' tumor antigens by chelation.

A procedure for ethylenediaminetetraacetate extraction of minced Wilm's tumor was assessed as a method for isolating Wilm's tumor antigens. An antigen was detected by immunodiffusion using an adsorbed antiserum to this extract. This antigen was also found in ethylenediaminetetraacetate extracts of in vitro cultures of nephroblastoma cells.