PubMed Health⌕ Search

Biomedical subjects

D M Thomson

Publications and source records attributed to D M Thomson.

At least 37 records · Page 2Linked to original sources
PubMed1986

Expression by human fetal organs of organ-specific cancer neoantigens as measured by leukocyte adherence inhibition.

Human cancers express organ-specific cancer neoantigens (OSN) as determined by in vitro leukocyte responses to extracts of cancers by the tumor host. In this study, we determined whether the OSNs were normal developmental proteins that were expressed by fetal organs and re-expressed with oncogenesis. Fetal extracts, principally of lung and colon but also of liver and kidney, were tested for their ability to induce leukocyte adherence inhibition (LAI) as compared to extracts from adult tissues of the same organ. Leukocytes from lung cancer patients showed positive LAI responses to 13- and 19-week fetal lung tissue. Likewise, leukocytes from colon cancer patients showed positive LAI responses to 14- and 19-week fetal colon tissue, whereas leukocytes from control subjects did not. Neither group responded positively to 21-week fetal organs. Criss-cross experiments showed that the fetal antigen was organ specific. Multiparous pregnant women showed positive LAI responses to cancer extracts but not to extracts from normal tissues of the same organ. The pattern of the LAI response was bell-shaped. Positive LAI responses to lung and breast cancer were detected at 4 to 7 months gestation and peaked at 5 months. To the fetal colon, LAI positive responses were detected at 5 to 8 months gestation, with the peak response at 6 months. The results indicate that OSN of cancers are also expressed by fetal organs and sufficient antigen is shed by fetal organs to sensitize pregnant women. Older fetal organs (21 weeks) and adult organs do not express an immunogenic or antigenic OSN.

Antigens, Neoplasm↗
PubMed1986

Leukocyte activation in advanced cancer as an explanation for absent leukocyte adherence inhibition to cancer extracts and chemoattractant.

Tube leukocyte adherence inhibition (LAI) measures human immunity by antigen-binding leukocytes releasing chemoattractant-like mediators that are the ultimate inhibitors of adherence by bystander leukocytes. We determined whether the absent LAI responses to cancer extracts for patients with large body burdens of bladder cancer was related to a defect in antigen binding or chemoattractant responsiveness. Leukocytes from patients with small body burdens of bladder cancer gave positive LAI responses of a similar extent to either bladder cancer extracts or chemoattractant [n-formyl-L-methionylleucylphenylalanine (FMLP)]. Of the adherent leukocytes, about 20-30% became non-adherent with a positive LAI response: monocytes, neutrophils and lymphocytes responded. In the control tubes, leukocytes from patients with large body burdens of bladder cancer were more non-adherent and about 15% less adherent than leukocytes from controls or patients with early cancer. They showed no further decrease in adherence, or conversely increase in non-adherence, with either extracts of bladder cancer or FMLP. The leukocytes also failed to transduce transmembrane signals to the same stimuli. The defect was reversible since PGE2 restored the adherence of leukocytes to normal, and subsequently they exhibited membrane potential changes and about 34% non-adherence to either bladder cancer extracts or FMLP. From these results we conclude that chemoattractant LAI-responsive leukocytes from patients with large body burdens of bladder tumor are activated in vivo, probably by mediators from inflammatory cells.

Cell Adhesion↗
PubMed1986

Identification of a Mr 40,000 polypeptide from colorectal cancer which expresses organ-specific cancer neoantigen activity as determined by leukocyte adherence inhibition.

Human cancers express organ-specific neoantigens (OSNs) that elicit immune responses in the tumor host. Leukocyte adherence inhibition, an in vitro assay that detects the antitumor immunity, was used to monitor the purification of the OSN from serum-free spent medium of tissue-cultured colon cancer cell lines (HCT-15 and SW-620). A monoclonal antibody (anti-p40) directed to a cross-reactive framework determinant of Mr 40,000 (p40) cell surface polypeptide, which was a principal component of the enriched isolate with OSN activity, was used to monitor the purification of p40 by enzyme-linked immunosorbant assay. About 50 liters of spent medium were generated from 20 m2 of cells, collected, concentrated, and then separated by anion exchange, molecular-sieve, and blue-Sepharose affinity chromatography. OSN and p40 activity coisolated. p40 was then purified by monoclonal antibody anti-p40 affinity chromatography. The affinity-purified fraction was enriched for both p40 and leukocyte adherence inhibition activity that was specific for leukocytes from colon cancer patients in blind leukocyte adherence inhibition assays. When affinity-purified p40 from colon and lung cancers was tested blind in a criss-cross fashion with leukocytes from colon and lung cancer patients, the positive responses were to the appropriate p40. The homologous colon cancer p40 molecule showed size and considerable charge microheterogeneity (pI 6.3 to 7.6). Affinity-purified p40 and OSN coisolated on hydrophobic interaction and hydroxylapatite high-pressure liquid chromatography. Note that not all colon cancer OSN activity was bound by the anti-p40 affinity column. However, unbound OSN activity also eluted from hydrophobic interaction high-pressure liquid chromatography at the same time as affinity-purified p40, and residual p40 activity was detected by enzyme-linked immunosorbant assay. The results indicate that a p40 glycoprotein from the cell membrane of colon cancer cells coisolates with fractions having OSN activity. Impurities do not seem to account for the OSN activity. The OSN epitope on the Mr 40,000 molecule is recognized by leukocytes from colon cancer patients and is distinct from the cross-reactive framework determinant recognized by mouse monoclonal antibody anti-p40.

Antibodies, Monoclonal↗
PubMed1985

Purification from a human lung cancer cell line of a water soluble molecule mediating leukocyte adherence inhibition for patients with lung cancer.

Soluble lung tumor activity as determined by LAI2 was enriched by physicochemical methods from chemically - defined spent medium of a lung cancer cell line (NCI-H69). To identify the polypeptide carrying the antigenic determinant, splenic lymphocytes of BALB/c mice were immunized with the enriched isolate and hybridized with mouse plasmacytoma cells. Eight hybrids were cloned successfully and produced MAbs that immunoprecipitated principally a single chain of Mr 40,000 (p40) as well as minor chains of Mr 25,000 (p25) and Mr 13,000 (p13) which were probably degradation products of p40. On 2D gels, p40 was composed of 7 spots with a p1 of 6.3 to 7.6, which was not altered by neuraminidase digestion. Affinity chromatography with MAb anti-p40 absorbed p40 and LAI activity. The bound and recovered fraction was enriched for p40 and LAI activity. Affinity-purified p40 also contained the previously identified p25 and p13 as well as a Mr 32,000 peptide (p32). MAb anti-p40 was directed to a common framework determinant on p40 since MAb anti-p40 bound to cancer cells from other organs. The comparatively lung cancer organ-specific determinant recognized by leukocytes from lung cancer patients was not recognized by the MAb. Affinity-purified p40 triggered LAI for leukocytes from patients with lung cancer but not for leukocytes from control subjects or patients with colon cancer or malignant melanoma in rigorous blind testing. Crossreactivity was observed with leukocytes from patients with breast cancer. LAI activity of affinity-purified p40 seems unlikely to result from an unidentified impurity. Thus a p40 molecule has been purified that is expressed on the membranes of lung cancer cells and triggers immunologically-mediated LAI.

Antibodies, Monoclonal↗
PubMed1985

Correlation between chemoattractant-induced leukocyte adherence inhibition, macrophage chemotaxis, and macrophage inflammatory responses in vivo.

Variations in the magnitude of inflammatory macrophage response in vivo and macrophage chemotaxis in vitro, observed among inbred mouse strains, suggest that these traits are genetically-regulated. The development of an A X B series of recombinant inbred (RI) strains of mice derived from the C57BL/6J (B, high responder) and A/J (A, low responder) resulted in the availability of a large number of new inbred strains which express a spectrum of variations in the magnitude of these traits. These strains were used in the present study as a tool to examine the possible correlation between the phenomenon of leukocyte adherence inhibition (LAI) and those of macrophage inflammatory response in vivo and macrophage chemotaxis in vitro under the assumption the LAI requires the same cellular events as chemotaxis and that LAI resembles, grossly, the accumulation of nonadherent inflammatory cells in vivo. The typing of A X B RI strains for the traits of LAI, macrophage accumulation in vitro, and macrophage inflammatory response in vivo resulted in a correlation between the magnitude of response of those three phenomena in the total of 19 inbred strains tested, thus suggesting that the chemoattractant-induced LAI is biologically related to the events that mediate macrophage chemotaxis in vitro and the macrophage inflammatory response to sterile irritants in vivo.

Animals↗
PubMed1985

Leukocyte adherence inhibition to myelin basic protein by cancer patients' T-lymphocytes in association with class II major histocompatibility antigens on monocytes.

Patients' leukocytes were shown to react consistently in tube leukocyte adherence inhibition (LAI) assays with myelin basic protein (MBP) at optimal concentration, whereas control leukocytes were nonreactive. Mononuclear cells from patients with cancer gave positive LAI reactions with MBP, but separated T-lymphocytes, monocytes, and neutrophils did not. The mononuclear cell LAI responses were blocked by monoclonal antibody (MAb) to monomorphic determinant of class II major histocompatibility complex (MHC) antigens and to T4+ (Leu-3a+) and T3+ (Leu-4+) T-cell differentiation antigens but not by antibody to class I MHC antigens or T8+ (Leu-2a+) antigens. MBP was thus recognized by helper T-cells, requiring presentation in association with class II MHC determinants on monocytes. MAb to class I and class II MHC antigens and to T8+ (Leu-2a+), T4+ (Leu-3a+), and T3+ (Leu-4+) differentiation antigens did not negate LAI mediated by peripheral blood lymphocytes to organ-specific cancer neoantigens (OSN) of crude extracts of allogeneic cancer, which had previously been shown to react with cytophilic antibody on allogeneic monocytes. When membrane OSN and leukocytes were autologous, T8+ (Leu-2a+) phenotypic T-cells also mediated LAI that was blocked by anti-T8 (Leu-2a) and anti-T3 (Leu-4). LAI induced by MBP was also negated by drugs that antagonize thromboxane-leukotriene biosynthesis, indicating that, in common with other LAI reactions, the terminal mediators of nonadherence are oxidative metabolites of arachidonic acid. In addition to clarifying the role of MBP in the cellular in vitro immunoreactivity of cancer patients, the present observations have important implications for theories of LAI. Sensitized leukocytes have different mechanisms for the recognition of antigens in different forms, and the antigen-stimulated leukocytes produce mediators that in a final common pathway induce nonadherence of surrounding cells through leukotriene-like metabolites.

Antibodies, Monoclonal↗
PubMed1985

T8 and T3 surface glycoproteins in human T-cell mediation of leukocyte adherence inhibition to extracts of autologous cancer.

Monoclonal antibodies (MAb's) [anti-Leu-1, anti-Leu-2a (T8), anti-Leu-3a (T4), and anti-Leu-4 (T3)] were used to elucidate the type of T-cell mediating leukocyte adherence inhibition (LAI) and the role of T-cell surface glycoproteins in LAI. T8+ (Leu-2a+) and T4+ (Leu-3a+) subtypes were isolated by panning. T8+ (Leu-2a+) cells showed LAI to extracts of autologous cancer, whereas the T4+ (Leu-3a+) subset had no LAI response. Moreover, MAb to the T8+ (Leu-2a+) glycoprotein negated T-cell LAI, but MAb to Leu-1+ or to T4+ (Leu-3a+) did not negate T-cell LAI to autologous cancer extracts. The T3+ (Leu-4+) differentiation also was essential for T-cell LAI to autologous cancer extracts since anti-Leu-4 (T3) negated the response. Since LAI to autologous cancer extracts depends ultimately on leukotriene and other oxidative metabolites of arachidonic acid generated by the T-cell binding tumor antigen, the effect of MAb on LAI induced by leukotriene B4 isomer III. 5(S), 12(R)-dihydroxy-6, 14-cis-8, 10-trans-eicosatetraenoic acid (LTB4) was examined. Authentic LTB4 induced nonadherence of 34% of adherent T-cells, and this effect was not negated by anti-Leu-1, anti-T8 (Leu-2a), or anti-T4 (Leu-3a). However, anti-T3 (Leu-4) abrogated LTB4-induced LAI of pure T-cells without any effect on the basic adherence properties of T-cells. The present findings indicated that LAI to autologous cancer extracts was mediated by T-cells of the T8+ phenotype when they recognize tumor antigen and polymorphic major histocompatibility complex determinants on autologous cancer membranes. Moreover, differentiation glycoproteins T8+ (Leu-2a+) and T3+ (Leu-4+) on the surface of the responding effector T-cells performed distinct biologic functions that enabled the tumor antigen to trigger T-cell LAI.

Antibodies, Monoclonal↗
PubMed1985

An isolated enriched organ-specific cancer neoantigen of human lung cancer for leukocyte adherence inhibition assays.

Until now, measurement of human antitumor immunity to organ-specific cancer neoantigen (OSN) by the leukocyte adherence inhibition (LAI) assay depended on using crude extracts of cancer. In this study, a new method is presented to generate and to isolate a highly enriched OSN from spent medium of a lung cancer cell line, NCI-H69, grown in chemically defined medium. Production of large quantities of OSN with minimal contamination by extraneous proteins was possible. Four physicochemical steps were used to give a 1000-fold enrichment of OSN activity: anion-exchange and molecular-sieve chromatography; Blue Sepharose affinity chromatography; and finally anion-exchange high-pressure liquid chromatography. The enriched OSN isolates showed dose-response antigenicity when tested in LAI assay with leukocytes from lung cancer patients but had no antigenicity with leukocytes from control subjects or patients having malignant melanoma, colon cancer, or pancreatic cancer. Cross-reactive antigenicity was observed with leukocytes from patients with breast cancer and slight reactivity with leukocytes from bladder cancer patients. The final isolate from the four-step separation procedure as well as the isolates produced using additional separation techniques consistently had antigenicity at less than 10 ng in blocking LAI and 500 ng in the direct assay and showed components with molecular weights of about 62,000 +/- 3,000 (SD) (p62), 40,000 +/- 3,000 (p40), and 25,000 +/- 1,000 (p25) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The OSN isolates on two-dimensional gels showed p40 to have microheterogeneity (seven spots), with a pl from 6.2 to 7.6, and p62 and p25 as even more basic streaks. The polypeptide bearing the antigenic determinant was not purified, although we tried to separate p62, p40, and p25 to determine whether they carried the OSN determinant. The results of this study are important in showing that an isolate of an organ-specific tumor antigen containing 5 to 13 components, as determined by highly sensitive silver stains and radiolabeled patterns on single and two-dimensional gels, can be used successfully in LAI to measure tumor immune responses.

Antigens, Neoplasm↗
PubMed1984

Transmembrane signal defect and absence of cancer extract induced leukocyte adherence inhibition (LAI) for leukocytes from patients with advanced cancer.

Leukocytes from patients with early cancer exhibit leukocyte adherence inhibition (LAI) when incubated with extracts of cancer of the same organ and histogenesis, whereas leukocytes from patients with advanced cancer seldom do. To understand the reason for this refractory state, tumor antigen-induced LAI and transmembrane signalling were measured in the same leukocytes. Transmembrane signalling was measured by changes in membrane potential (delta psi) by the [3H]tetraphenylphosphonium equilibration technique. When leukocytes from patients with early breast cancer were incubated with extracts of breast cancer and malignant melanoma they showed delta psi changes consisting of depolarization and hyperpolarization beginning within 0.5 min after addition of the breast cancer extract and finishing 15 min later. Moreover, they showed no delta psi changes when incubated with extracts of normal breast tissue. Leukocytes from subjects without cancer seldom showed delta psi changes. In criss-cross experiments, leukocytes from patients with melanoma only exhibited delta psi changes when incubated with the melanoma extract. There was a strong correlation between cancer extract-induced delta psi change and LAI. The delta psi change was triggered by leukotriene-like mediators from antibody-dependent monocytes. Authentic leukotrienes triggered delta psi changes in all subpopulation of leukocytes. Leukocytes from patients with advanced breast cancer when incubated with breast cancer extract did not transmit a signal or show LAI. Brief elevation of intracellular cyclic AMP restored both delta psi change and LAI induced by breast cancer extracts, indicating that reactive leukocytes are present but in a refractory state. We conclude that leukocytes from patients with advanced cancer do not react in LAI because tumor antigen does not trigger a transmembrane signal to initiate the cascade of biochemical reactions and physiological changes for LAI.

Breast Neoplasms↗
PubMed1984

Evidence in advanced cancer of an activated leukocyte state to explain the reversible defect in transmembrane signaling and leukocyte adherence inhibition to extracts of cancer.

When leukocytes bind tumor antigen, a transmembrane signal induces the cascade of physiological changes that result in leukocyte adherence inhibition (LAI). Leukocytes from patients with early stages of cancer exhibited transmembrane potential (delta psi) changes and LAI when incubated with a cancer extract of the same organ and histogenesis, whereas leukocytes from patients with advanced cancer did not. The refractoriness was reversed by transiently raising intracellular cyclic AMP. LAI is produced by leukotrienes and leukocytes from patients with advanced cancer were refractory to leukotriene-induced delta psi changes which was also restored by raising intracellular cyclic AMP. Moreover, leukocytes could be made refractory to delta psi changes: leukocytes from patients with early cancer when preincubated with a breast cancer extract showed no delta psi change with a second exposure; and leukocytes from control subjects preincubated with leukotrienes showed no delta psi change with a second exposure. The responsive population of leukocytes in LAI to either the specific cancer extract or leukotrienes consisted of about 35 to 42% of the adherent leukocytes. The responsive leukocytes in advanced cancer were already nonadherent, accounting for the 39% increased nonadherence with the control extract. Raising cyclic AMP decreased nonadherence by 39%. The results suggest that leukotrienes and other chemoattractants released in vivo by immune cells binding tumor antigen have stimulated the changes in leukocytes in advanced cancer. However, the unresponsiveness seems to be because of appropriate expression of physiological changes triggered by antigen and chemoattractant stimuli.

Breast Neoplasms↗
PubMed1984

Various authentic chemoattractants mediating leukocyte adherence inhibition.

This study resulted from the finding that cancer extract-induced leukocyte adherence inhibition (LAI) depends on release of arachidonic acid metabolites of which leukotriene B4 (LTB4) is a chemoattractant. Leukotrienes, the chemotactic fragment of the fifth component of complement (C5a des arg), N-formyl-L-methionylyl-L-leucyl-L-phenylalanine (FMLP), platelet-activating factor (PAF), and phorbol myristate acetate (PMA) increased the nonadherence of human leukocytes to glass with bell-shaped dose-response curves. For maximum nonadherence, the optimum concentration was about 2 X 10(-11) M LTB4, 10(-9) M C5a des arg, 2 X 10(-8) M FMLP, 2 X 10(-9) M PAF, and 2 X 10(-8) M PMA. Of the adherent leukocytes, 29% became nonadherent. Higher concentrations of leukotriene E4, FMLP, PAF, and PMA induced leukocyte hyperadhesiveness. Chemoattractant-induced LAI was antagonized by inhibitors of glycolysis, oxidative metabolism, electron transport, microfilaments, and microtubules, whereas the same concentration of inhibitors did not alter the adherence of leukocytes to glass in control tubes. T-cells, neutrophils, and mononuclear cells showed LAI to LTB4, C5a des arg, and FMLP. Moreover, no additive effect was observed when leukocytes exposed to a first chemoattractant at its optimum concentration were exposed to a second. A competitive inhibitor of leukotriene slow-reacting substance of anaphylaxis, FPL 55712, blocked in a dose-response fashion LTB4-, C5a des arg-, and FMLP-triggered LAI. Eicosatetraenoic acid and nordihydroguaiaretic acid, cyclo-oxygenase-lipoxygenase pathway inhibitors, also markedly antagonized LTB4-, C5a des arg-, and FMLP-triggered LAI. Indomethacin (10(-5) M), piroxicam (10(-6) M), and aspirin, cyclooxygenase antagonists, negated LTB4-, C5a des arg-, and FMLP-induced LAI. Prostaglandins E2, E1, and F2 and prostacyclin did not trigger LAI. However, selective thromboxane synthetase antagonists completely negated chemoattractant-triggered LAI. Our studies indicated that chemoattractants stimulated leukocytes to produce thromboxanes, which increased leukocyte nonadherence.

Carbonyl Cyanide m-Chlorophenyl Hydrazone↗
PubMed1984

Reversible abnormal nonadherence to glass and responsiveness to chemoattractants of leukocytes from patients with advanced cancer.

Whereas leukocytes from patients with early cancer usually show leukocyte adherence inhibition (LAI) to the sensitizing cancer extract, leukocytes from patients with advanced cancer seldom do. The chemoattractant-induced LAI response was studied to determine whether the abnormal response by leukocytes from patients with advanced cancer was related to changes in sensitivity to chemoattractants. Authentic chemoattractants N-formyl-L-methionyl-L-leucyl-L-phenylalanine, chemotactic fragment of the fifth component of complement, and leukotriene B4 (LTB4) at optimum concentrations induced about 28-31% of adherent leukocytes to become nonadherent, these leukocytes being from either controls or patients with early breast cancer. However, chemoattractants induced no increased nonadherence of adherent leukocytes from patients with advanced breast cancer. In the control tubes, nonadherent cells for patients with advanced cancer were already increased by about 38% and were slightly greater than the chemoattractant-induced increased of nonadherent cells for control subjects or patients with early cancer. When the intracellular cyclic AMP of the cells were raised transiently, the nonadherent cells in the control tubes for patients with advanced cancer decreased by about 38% compared to 8% for control subjects and 13% for patients with early cancer. When nonadherence was returned to control levels, about 46% of adherent cells from patients with advanced cancer became nonadherent to chemoattractants or to the sensitizing cancer extract. Normal leukocytes, preexposed to chemoattractants, had increased nonadherence and did not respond to the same or other chemoattractants, imitating the state of leukocytes from patients with advanced cancer. However, if the cells were washed and intracellular cyclic AMP raised, nonadherent cells returned to normal levels in the control tubes and showed increased nonadherence with a repeat LTB4 exposure. The increased nonadherence of leukocytes from patients with advanced cancer as well as the refractoriness to chemoattractants was highly suggestive of in vivo activation of leukocytes possibly because of exposure to chemoattractant-like factors, generated by leukocyte-tumor antigen interactions.

Breast Neoplasms↗
PubMed1984

Requirement for autologous cancer extracts and lipoxygenation of arachidonic acid for human T-cell responses in leukocyte adherence inhibition and transmembrane potential change assays.

Assays of leukocyte adherence inhibition (LAI) and transmembrane potential (delta psi) change were used to examine the responses of T-cells from control subjects and breast cancer patients when incubated with extracts of breast cancer and other tissues. Of T-cells from 25 patients with breast cancer, 21 exhibited delta psi changes or inhibition of adherence to glass when they were incubated with extracts of autologous but not allogeneic breast cancer; extracts of autologous normal breast tissue did not induce delta psi changes or LAI in T-cells from patients with breast cancer. Supernatants were collected after incubating 1 X 10(7) T-cells from patients with breast cancer or from control subjects with extracts of the autologous cancer. When the supernatants were added to either peripheral blood leukocytes or mononuclear cells from normal donors, neither delta psi changes nor LAI were detected. To still determine whether the nonadherence was mediated by chemoattractant lymphokines, the effect of inhibiting T-cell arachidonic acid metabolism was examined. The lipoxygenase pathway antagonist, 5,8,11,14-eicosatetraynoic acid, or a leukotriene antagonist, FPL 55712, inhibited T-cell LAI, but a cyclooxygenase pathway antagonist, indomethacin, did not. Moreover, authentic leukotriene B4 induced delta psi changes and LAI in T-cells. The results indicated that T-cells from patients with breast cancer recognized and bound a tumor-specific antigen in the autologous neoplastic breast tissue that transduced a transmembrane signal to trigger a series of biochemical changes, releasing lipoxygenase products of arachidonate. The lipoxygenase products, which may be important in the inflammatory response to cancer, induced a loss of T-cell adherence to glass.

Arachidonic Acid↗
PubMed1984

Blocking of the response by human T-lymphocytes to extracts of autologous cancer by monoclonal antibody to Class-I major histocompatibility complex gene products in the leukocyte adherence inhibition assay.

In the leukocyte adherence inhibition (LAI) assay, about 34% of adherent T-cells from patients with breast cancer exhibit nonadherence to glass when incubated with extracts of autologous cancer but not with HLA-A, -B, and -C mismatched extracts of breast cancer. To determine whether the recognition by T-cells of tumor antigen was major histocompatibility complex restricted, major histocompatibility complex antigens in the cancer extracts or on the T-cells were coated with monoclonal antibody (MAb) to nonpolymorphic determinants. Nonadherence of T-cells was antagonized by coating the target cancer extracts with MAb to a common framework determinant of Class I HLA-A, -B, and -C antigens or to the nonpolymorphic beta 2-microglobulin, which is noncovalently associated with Class I antigens. By contrast, a MAb to a monomorphic determinant on HLA-DR antigens did not change the positive T-cell response. Moreover, coating the T-cells with MAb to HLA-A, -B, and -C did not inhibit the positive T-cell response. The positive LAI response of buffy coat peripheral blood leukocytes from patients with breast cancer to extracts of allogeneic breast cancer was not affected by coating the cancer extracts with the same MAb, indicating that MAb inhibited T-cell LAI specifically and that the antibody-dependent LAI response of buffy coat peripheral blood leukocytes was not major histocompatibility complex restricted. The results indicate that HLA-A, -B, and -C antigens in extracts of autologous breast cancer restrict the LAI response to tumor antigens of T-cells from patients with breast cancer.

Antibodies, Monoclonal↗