Expression of human choriogonadotropin-like material in coagulase-negative Staphylococcus species

Abstract

We identified 101 coagulase-negative Staphylococcus strains obtained from different laboratories, the American Type Culture Collection, and our collection, isolated from 23 patients with overt cancer and 34 normal individuals through Kloos and Schleifer conventional methods and the Staph-Ident staphylococcal system (Analytab Products, Plainview, N.Y.). In 40 strains, identity was further verified by DNA-DNA hybridization techniques. Identification revealed 39 S. epidermidis, 22 S. hominis, 8 S. haemolyticus, 9 S. capitis, 5 S. warneri, 5 S. cohnii, 8 S. saprophyticus, and 5 S. xylosus strains, all resident species found in humans. All bacteria were tested for the expression of human choriogonadotropin (hCG)-like material by the indirect fluorescein and peroxidase immunocytochemical labeling techniques by using specific antisera to the whole hormone, to its a and fi subunits, to the hCGji COOH-terminal peptide, and to a monoclonal antibody to the hCG,. The results demonstrated that (i) the isolates from cancer patients were not unique bacteria, as has been postulated by others; (ii) the expression of immunoreactive hCG-like material is a strain, not a species, characteristic; (iii) not every bacterial strain isolated from a cancer patient is able to express the material; (iv) hCG-producing bacteria do not necessarily indicate the presence of active disease; (v) 20% of the strains that we studied revealed a clonal variation of the expression of hCG-like material or its subunits or both as well as a variable expression of a single hCG epitope, an observation similar to that described for malignant cells; and (vi) a specific antiserum to the whole hormone with a high affinity and high sensitivity for immunocytochemistry can be a reliable reagent for screening purposes.

Antibodies to bacterial vaccines demonstrating specificity for human choriogonadotropin (hCG) and immunochemical detection of hCG-like factor in subcellular bacterial fractions

“…These antibodies were immunologically similar to the antibodies produced by hCG, since we found that the antibodies to the bacteria containing the hCG-like material also cross-reacted with hLH (Table 1). The data also demonstrated that the bacterial material could be extracted by disruption of the cell membranes and that the expression of the hCG-like protein by bacteria is a strain characteristic and not a species characteristic, confirming the results from our immunocytochemical studies (1). Bacteria within the same species shown by immunocytochemistry to be devoid of the hormone-like protein (Fig.…”

“…Peroxidase staining was done with 3-amino-9-ethlycarbazole (Sigma Chemical Co., St. Louis, Mo.). This bacterial strain has also shown reactivity with another monoclonal antibody to hCG, that reacts with an epitope different to the one reacting with antibody 337W, and with polyclonal antisera to whole hCG, to hCGI3, to the hCG, COOH-terminal peptide residues 115 through 145, and to hCGcx (1). Streptococcus bovis AV46 has also shown a positive reaction with the same reagents.…”

“…The production of the trophoblastic hormone FIG. 1. Immunocytochemical detection of hCG3-like material in Staphylococcus haemolyticus RUL.…”

“…Bacteria exist that express a human choriogonadotropin (hCG)-like material with in vitro and in vivo biological activity similar to that of the human trophoblastic hormone (1, 3-5, 7, 10, 18). Because the hCG-like material has been demonstrated on the surface of whole bacterial cells (1,(3)(4)(5)22), an investigation was done to determine whether immunization of rabbits with vaccines prepared with hCGproducing bacteria elicit antibodies with specificity for the hCG epitopes. We also attempted to determine the anatomical locus of the hCG-like material by separating subcellular fractions while preserving the cell structures that have shown hCG-like material by immunoelectron microscopy (22).…”

Human chorionic gonadotropin (hCG), the hormone of life and death: a review

“…Unicellular organisms like bacteria and yeasts have been identified to acquire genes of certain hormones. Of fundamental importance is the fact that some bacteria isolated from cancer patients expressed hCG, but not every isolated bacteria did (28–33). Moreover, the morphologic changes observed by electron microscopy (34) indicated that some of the bacteria expressing the hCG‐like material are revertants of cell wall deficient (CWD) variants.…”