Abstract: A method for blocking suppression of at least one of the natural killer (NK) and lymphocyte activated killer (LAK) cytotoxicity mechanisms in lymphocytes of cancer patients comprises administering to a cancer patient an agent capable of blocking the cytotoxicity suppressive activities of a peptide capable of inducing a detectable decrease in the structuredness of the cytoplasmic matrix in lymphocytes isolated from a patient with cancer (an SCM-factor peptide) in a quantity sufficient to block suppression of at least one of the natural killer (NK) and lymphocyte activated killer (LAK) cytotoxicity mechanisms. The agent can comprise an antibody or an antisense peptide. The invention also includes pharmaceutical compositions and kits for blocking suppression of cytotoxicity.

Abstract: Disclosed are antibodies to peptides active in the structuredness of the cytoplasmic matrix test (SCM-factor peptides) and to fragments of the peptides by immunization of antibody-producing animals with the peptides or fragments. Both polyclonal and monoclonal antibodies can be prepared. Particularly useful are antibodies specifically binding the peptides M-I-P-P-E-V-K-F-N-K-P-F-V-F-L-M-I-D-Q-N-T-K-V-P-L-F-M-G-K (SEQ ID NO: 2) and F-L-M-I-D-Q-N-T-K (SEQ ID NO: 3). The antibodies can be labeled and are suitable for performing immunoassays to detect the presence of SCM cancer-recognition factors in cell cultures or body fluids.

Abstract: A cancer recognition factor (SCM factor) useful in the performance of the structuredness of the cytoplasmic matrix (SCM) test has been isolated, purified to substantial homogeneity, and characterized, and methods for its use have been described. The factor is a peptide of at least 9 amino acid residues including a core sequence of 9 amino acid residues having an amphipathicity profile substantially equivalent to that of the sequence F-L-M-I-D-Q-N-T-K and produces at least a 10 percent decrease in the intracellular fluorescence polarization value of SCM-responding lymphocytes from donors afflicted with cancer. A synthetic SCM factor representing a consensus sequence of M-I-P-P-E-V-K-F-N-K-P-F-V-F-L-M-I-D-Q-N-T-K-V-P-L-F-M-G-K is fully active. Antibodies specific for SCM factor are useful in immunoassays that can detect the factor, including detection in cancer cells grown in vitro.

Abstract: An improved method and apparatus for measuring polarized fluorescence emissions compensates for background emissions without separating a fluorescing material from background material. The method involves measuring the horizontally and vertically polarized components of the fluorescence emission at a primary wavelength and at least one secondary wavelength selected on the basis of the bathochromic shift of the spectrum of the fluorescence emissions from the fluorescing material as compared to the fluorescence emissions from the background. From these measurements, a factor representing the fraction of the total intensity of fluorescence emissions due to background fluorescence is determined. From this factor, the intensities of the vertically and horizontally polarized fluorescence emissions due to background fluorescence are derived and subtracted from the measurements at the primary wavelength to obtain intensities due solely to the material being analyzed.

Abstract: A cancer recognition factor (SCM factor) useful in the performance of the structuredness of the cytoplasmic matrix (SCM) test has been isolated, purified to substantial homogeneity, and characterized, and methods for its use have been described. The factor is a peptide of at least 9 amino acid residues including a core sequence of 9 amino acid residues having an amphipathicity profile substantially equivalent to that of the sequence F-L-M-I-D-Q-N-T-K and produces at least a 10 percent decrease in the intracellular fluorescence polarization value of SCM-responding lymphocytes from donors afflicted with cancer. A synthetic SCM factor representing a consensus sequence of M-I-P-P-E-V-K-F-N-K-P-F-V-F-L-M-I-D-Q-N-T-K-V-P-L-F-M-G-K is fully active. Antibodies specific for SCM factor are useful in immunoassays that can detect the factor, including detection in cancer cells grown in vitro.

Abstract: An improved method is provided for the isolation of lymphocytes for use in the SCM test for the detection of cancer and other diseases and conditions. The method of the present invention can isolate either or both of the SCM-responding lymphocyte fractions from the same blood sample: the F2 fraction, with a buoyant density of 1.0590 g/cm.sup.3 to 1.0670 g/cm.sup.3 measured at 20.degree. C. in a solution having an osmolality of about 0.315 Osm/kg, and the F4 fraction, with a buoyant density of 1.0690 g/cm.sup.3 to 1.0730 g/cm.sup.3. These lymphocyte fractions are isolated in visible bands and are substantially free of lymphocytes having other buoyant densities. This avoids cross-contamination of the lymphocyte fractions with each other as well as with SCM non-responding lymphocytes. Several gradients useful in this isolation method are described. This isolation method can use as starting material either a blood sample depleted of phagocytic cells or the total population of lymphocytes.

Abstract: The SCM (structuredness of cytoplasmic matrix) test is a means of distinguishing lymphocytes isolated from mammalian donors, including humans, afflicted with cancer from lymphocytes isolated from donors free of malignancy. The test comprises contacting the lymphocytes with a challenging agent and then observing a decrease in the structuredness of the cytoplasmic matrix in lymphocyte from donors with cancer; lymphocytes from donors without cancer show no decrease in structuredness. Preferably the decrease in structuredness is quantified by measuring the fluorescence polarization for an extrinsic fluor added to the cells and observing a decrease in fluorescence polarization after lymphocytes from a donor with cancer have been contacted with a challenging agent. Among the challenging agents useful in the SCM test are several synthetic peptides which are the subject of the present invention.

Abstract: An improved method for measuring polarized fluorescence emissions compensates for background emissions without separating a fluorescing material from background material contributing background fluorescence. The method is particularly useful in measuring fluorescence from a suspension of cells such as stimulated lymphocytes in the SCM assay, where the intracellular fluorescence is due to the penetration of the cells by a fluorogenic agent precursor and its subsequent hydrolysis. The method involves measuring the horizontally and vertically polarized components of the fluorescence emission at a primary wavelength and at least one secondary wavelength. The secondary wavelength is selected based on the bathochromic shift of the spectrum of the fluorescence emissions from the fluorescing material as compared to the fluorescence emissions from the background.

Abstract: The method of the present invention comprises contacting a suspension of viable lymphocytes with a solution containing a membrane potential sensitive fluorescent dye. The contact between the lymphocyte suspension and the MPS dye is maintained for sufficient time to permit labelling of the lymphocytes by the MPS dye material. The labelled lymphocytes are passed individually through a focused source of excitation energy causing any MPS dye material to fluoresce. The fluorescent emission from each cell is recorded as a pulse and the number of pulses of each intensity are recorded. The distribution of the number of pulses versus the intensity is prepared distribution is bimodal. A first peak includes pulses of low fluorescence intensity and a second peak comprises pulses of high fluorescence intensity.