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Biomedical subjects

E Klein

Publications and source records attributed to E Klein.

At least 163 records · Page 9Linked to original sources
PubMed1993

Loss of T-cell receptor zeta chain and p56lck in T-cells infiltrating human renal cell carcinoma.

Cancer patients and mice bearing tumors develop a progressive immunosuppression manifested by a decreased delayed-type hypersensitivity, decreased T-cell lytic activity, diminished production of lymphokines, and a reduced T-cell proliferative response. The mechanisms underlying these changes are incompletely understood. We recently reported the presence of marked alterations in signal transduction in T-cells from mice bearing long-term (28-day) tumours. We hypothesized that a soluble product produced by the tumor or resulting from the immune response to tumor might be responsible for inducing the changes in T-cells. Tumor-infiltrating lymphocytes from patients with renal cell carcinoma tested here showed, in 10 of 11 cases, a marked decrease in the expression of the T-cell receptor zeta chain and in p56lck tyrosine kinase. The presence of major alterations in the tumor-infiltrating lymphocytes with only minor changes in the peripheral blood leukocyte T-cells supports the notion that the defects are induced by exposure to tumor. These results suggest that tumor-infiltrating lymphocytes may be compromised in their antitumor efficacy in patients with renal cell cancer.

Carcinoma, Renal Cell↗
PubMed1993

Correlation between the growth-inhibitory effect of TGF-beta 1 and phenotypic characteristics in a panel of B-cell lines.

Human B-cell lines established from Burkitt lymphoma (BL) and normal B cells immortalized in vitro by EBV (LCLs) differ in phenotype. While the BL correspond to resting B cells, the LCLs resemble activated B cells. When BLs which have the EBV genome are carried in vitro, they acquire some of the features of LCLs, such as expression of B-cell activation markers and the tendency to form aggregates. Comparison of several B-cell lines for sensitivity to TGF-beta showed that the growth of BLs (with few exceptions), but not of the LCLs, was inhibited. The results suggested that the sensitivity to TGF-beta correlates with the cellular phenotype. In the present work, this assumption is even more critically substantiated by studying 2 sublines of an EBV-genome carrying BL line, Mutu, which were selected for single cells and aggregates. The former (with resting phenotype) was inhibited, while the subline of aggregated cells, which also expressed B-cell activation markers, was not inhibited. Somatic-cell hybrids between BLs, LCLs and non-B cells provided lines with phenotypic differences. Results with a panel of such hybrid lines also showed that those which express the activated B-cell phenotype are not inhibited by TGF-beta. Differences in the levels of expression of activation markers did not influence the response to TGF-beta.

B-Lymphocytes↗
PubMed1993

Selectively down-regulated expression of major histocompatibility complex class I alleles in human solid tumors.

We studied the expression of major histocompatibility complex (MHC) class I molecule in 52 ex-vivo tumor samples comprising 29 ovarian, 15 lung, 1 breast, and 4 colon carcinomas; 1 midgut carcinoid; and 2 malignant mesenchymal tumors obtained from surgical specimens or from malignant effusions. The allelic products were visualized in untreated and interferon gamma + tumor necrosis factor alpha treated aliquots of tumor cells and in the patient's blood lymphocytes by the one-dimensional isoelectric focusing method. Generally, the tumor cells contained lower amounts of MHC class I molecules compared to the lymphocytes. In vitro exposure to interferon gamma and tumor necrosis factor alpha elevated the level of MHC class I expression in 24 of 52 tumors and corrected the assembly defect seen in 2 cases. In 20 tumors one or several human leukocyte antigen alleles were undetectable even after cytokine treatment. Correlation was seen with the grade of differentiation; the proportion of tumors with selective losses in poorly, moderately, or well differentiated tumors were 16 of 30, 3 of 13, and 1 of 9, respectively. Selective losses occurred in ovarian carcinoma cells collected from malignant effusions (12 of 22, 54%) but not in 7 primary tumors. In primary lung carcinomas the frequency was 36% (5 of 14 cases). Thirty-nine patients were serologically typed; thus the MHC alleles on the tumor cells could be identified. In this panel of tumors 30 human leukocyte antigen alleles were represented. Among these the expression of 15 was found to be down-regulated in some but not all tumors of the same histology.

Alleles↗
PubMed1993

Interleukin 7 enhances the proliferation and effector function of tumor-infiltrating lymphocytes from renal-cell carcinoma.

Previous studies have documented the effects of IL2 on the growth and effector function of tumor-infiltrating lymphocytes (TIL) in cancer patients. Since IL7 is known to induce T- and NK-cell responses in the peripheral blood, we examined the immuno-enhancing effects of IL7 on TIL derived from human renal-cell carcinoma (RCC). Whereas IL2 induced the growth of freshly isolated TIL in vitro, IL7 was ineffective alone and failed to increase the total number of cells proliferating to IL2. However, IL7 did provide a proliferative signal to TIL that were initially expanded in culture with either IL2 or IL2/IL7 for 2 weeks. IL7 also induced the proliferation of CD4+ and CD8+ TIL lines that have specificity for RCC. The proliferative response induced by IL7 was independent of IL2, since anti-IL2 antibodies did not block IL7-induced proliferation of TIL. IL7 did cooperate with anti-CD3 stimulation for the induction of proliferation; however, the magnitude of this interaction was variable and the response usually additive. In addition, IL7 synergized with anti-CD3 to induce the secretion of IFN gamma from short-term-cultured TIL and from a TIL line. Although IL7 did not promote the development of a tumor-specific T-cell response from IL2-expanded TIL, IL7 enhanced lymphokine-activated killer (LAK) activity from some short-term-cultured TIL. These results illustrate that IL7 can potentiate the growth and production of IFN gamma from RCC-reactive TIL and, to a lesser extent, enhance IL2-induced LAK activity of TIL.

Carcinoma, Renal Cell↗
PubMed1993

T-cells infiltrating renal cell carcinoma display a poor proliferative response even though they can produce interleukin 2 and express interleukin 2 receptors.

The fact that progressing tumors contain a significant infiltrate of T-cells brings into question the competency of the infiltrating T-lymphocytes (T-TIL). We have examined the role of the T-cell receptor/CD3 complex and/or the interleukin 2 receptor (IL2R) in responsiveness of T-cells that infiltrate human renal cell carcinoma. T-TIL display a poor proliferative response to interleukin 2 (IL2) alone, IL2 in combination with antibody to CD3, or mitogen stimulation. The proliferative unresponsiveness was not related to low expression of CD3 or IL2R beta as the percentage of T-cells expressing CD3 and IL2R beta were comparable in both T-TIL and peripheral blood T-cells obtained from the same patient. In contrast to the lack of proliferative activity, stimulation of T-TIL or peripheral blood lymphocytes with phytohemagglutinin or anti-CD3 resulted in comparable levels of both IL2 and gamma-interferon mRNA and protein expression. While levels of IL2R alpha were low in unstimulated T-TIL and peripheral blood lymphocytes, anti-CD3 antibody or IL2 were capable of inducing surface expression of this protein in both cell populations. IL2R alpha mRNA levels were comparable in T-cells from the tumor and peripheral blood although in some experiments both the percentage of IL2R alpha-positive cells and the density of surface expression per cell were reduced in T-TIL. This reduced IL2R alpha expression on T-TIL was not responsible for the proliferative unresponsiveness since T-TIL that expressed both IL2R alpha and/or IL2R beta still failed to respond to high doses of IL2. Thus T-TIL display a selective loss of response to at least two well defined extracellular stimuli. While T-TIL exhibit a poor proliferative response regardless of the form of stimulation these cells remain sensitive to both anti-CD3 and IL2 in terms of IL2 and gamma-interferon or IL2R alpha expression, respectively. The fact that proliferative unresponsiveness exists even though T-TIL can produce IL2 and express IL2R alpha/beta suggests that T-TIL have a selective loss of a common intracellular signaling pathway which is requisite to proliferation but not other aspects of response to antigenic stimulation.

Adult↗
PubMed1993

Salvage surgery for radiation failure in prostate cancer.

METHODS: Salvage surgery was done in 43 patients who did not respond to radiation therapy of prostate cancer between 1982-1991. Thirty-five patients underwent salvage prostatectomy and 8, cystoprostatectomy. RESULTS: The complications were significant; four patients had rectal injuries (all closed primarily), one had a ureteral injury, and there was one perioperative death. Urinary incontinence occurred in 10 of 35 patients (30%). Pathologic step sections of the prostate showed that only 13 of 43 patients (30%) had negative surgical margins. Follow-up (range, 1-10 years) revealed that 34 patients were alive, and 9 had died. Eleven of 20 patients were alive who were followed more than 5 years. Ten patients were considered to have no evidence of disease (undetectable prostate specific antigen levels). CONCLUSION: In selected patients, salvage surgery has a place in the treatment of prostate cancer after radiation therapy failure.

Aged↗
PubMed1993

Reduced expression of major histocompatibility complex class I free heavy chains and enhanced sensitivity to natural killer cells after incubation of human lymphoid lines with beta 2-microglobulin.

Enhancement of major histocompatibility complex (MHC) class I expression leads to protection from recognition by natural killer (NK) cells in several systems. MHC class I gene products can be expressed in different forms at the cell surface--for example as "empty" beta 2-microglobulin (beta 2m)-associated heterodimers or free heavy chains. To study the role of different class I heavy chain forms in NK target interactions, we have used lymphoblastoid target cell lines preincubated with beta 2m. This was found to shift the equilibrium between beta 2m-associated and non-associated--heavy chains in favor of the former. In parallel, there was a significant increase in NK sensitivity. The recognition of MHC class I-deficient cell lines was not affected by beta 2m, arguing against a general nonspecific effect of beta 2m on NK sensitivity. Our data indicate that protection against NK recognition correlates with target cell expression of free heavy chains (i.e. devoid of beta 2m) rather than with expression of complexes.

Cell Line↗
PubMed1993

Increased expression of MHC class I molecules on human cells after short time IFN-gamma treatment.

Human cell lines and blood lymphocytes were treated for short time periods with IFN-gamma. This treatment increased the amount of the assembled MHC class I molecules on the plasma membrane after 30 min. This early increase of the membrane expression subsided in the next few hours. A second wave of elevation occurred after 8-24 hr. Analysis of cytoplasmic and membrane molecules in pulse chase experiments showed that the cytokine enhanced both the assembly of available heavy and light chains and the transport of the complex to the plasma membrane. The membrane level of the HLA-A2 molecules showed similar kinetics. Addition of an A2 specific binding peptide stabilized the IFN-gamma induced molecules on the cell surface. It seems that IFN-gamma alone or together with a binding peptide can influence MHC class I expression solely through post-transcriptional events utilizing an available pool of free heavy and light chains already after a short time, before the enhancement of the synthesis starts.

Amino Acid Sequence↗
PubMed1993

Enhancement of Fc epsilon RII/CD23 expression on U937 cells with opsonized zymosan: the requirement of a Fc gamma RI/CD64 mediated signal associated phagocytosis.

The kinetics of surface Fc epsilon RII/CD23 was tested on monocytic cell line U937 stimulated with opsonized zymosan. Zymosan opsonized with human serum enhanced not only the expression of surface Fc epsilon RII/CD23 but also Fc epsilon RII/CD23 mRNA detected by Northern blot and in situ hybridization techniques. This stimulation showed a marked synergism with IL-4 in the induction of Fc epsilon RII/CD23. Heat-inactivation of serum did not affect the inducibility of Fc epsilon RII/CD23 by opsonized zymosan, suggesting the involvement of serum substances other than complement. Zymosan treated with human gamma-globulin also induced Fc epsilon RII/CD23, indicating the possible involvement of Fc gamma receptors. The Fc epsilon RII/CD23 inducing effect of opsonized zymosan was partially blocked by pretreatment with heat-aggregated human gamma-globulin or an anti-Fc gamma RI monoclonal antibody but not by the anti-Fc gamma RII or Fc gamma RIII antibody. Our results showed the involvement of signals from Fc gamma receptor associated phagocytosis in the induction of Fc epsilon RII/CD23.

Blotting, Northern↗
PubMed1993

Induction of the lytic viral cycle in Epstein Barr virus carrying Burkitt lymphoma lines is accompanied by increased expression of major histocompatibility complex molecules.

Six Epstein Barr virus (EBV) genome-carrying Burkitt lymphoma (BL) cultures (P3HR-1, Raji, Akata, Daudi, Rael and Jijoye) were induced to enter the lytic cycle. Phorbol esther (TPA), n-butyrate, 5-azacytidine (5AzaC) or anti-IgG were used according to their known inducing capacity on these cell lines. Concomitantly with the appearance of the viral early antigens (EA) in a proportion of cells, the expression of major histocompatibility complex (MHC) class II antigens increased in the cultures. On P3HR-1 and Raji cells class I expression also increased. The enhancement of MHC expression correlated with the efficiency of induction and required only an early event of the viral lytic cycle. Treatment of 3 EBV-negative lymphoma lines (BJAB, Ramos and BL41) with TPA plus n-butyrate or 5AzaC did not influence MHC expression. Moreover, BL lines which carry the EBV genome after having been infected in vitro and which cannot be induced for the viral lytic cycle did not change MHC expression after treatment with the inducing agents. In mixed cultures the allo-stimulatory capacity of induced cells with elevated MHC expression was stronger compared to the untreated ones.

Burkitt Lymphoma↗
PubMed1993

HRF20/CD59 complement regulatory protein expression is phenotype-dependent and inducible by the hypomethylating agent 5-azacytidine on Burkitt's lymphoma cell lines.

We studied the expression of the 20-kDa homologous restriction factor (CD59/HRF20), a complement regulatory protein, on two subsets of blood derived B cells and on Burkitt's lymphoma lines. Both low-density (activated) and high-density (resting) B cell populations expressed high levels of CD59. CD59 was detectable, however, only on a minority of cells or not at all on three Epstein-Barr virus (EBV)-negative BL lines (BL41, BL28 and DG75) and on clones of an EBV-positive BL line (Mutu) that phenotypically resembled resting B lymphocytes. On the other hand, CD59 was detected at high or medium levels on Mutu cells which had a lymphoblastoid cell-like phenotype. Expression of CD59 was upregulated by 5-azacytidine, a drug inhibiting cytosine methylation, on CD59-negative cell lines. Induction was accompanied by a partial hypomethylation in the 5' region of CD59 coding sequences.

Antigens, CD↗
PubMed1993

Red-cell bound anti-A is more efficient than anti-B in competition for fluid phase complement.

Lysis of group A and B erythrocytes by human complement was studied by an anti-A (BRIC.131) and an anti-B (BRIC.30) IgM monoclonal antibody in a 51Cr-release assay. The relative concentration of membrane-bound immunoglobulins was detected by flow cytometric analysis, and the amount of C1q and C3 bound to the sensitized red cells was measured by using purified, 125I-labelled molecules. The direct haemolysis was identical with both reagents in the presence of excess and suboptimal complement over a wide range of antibody concentration (between 50 and 7000 ng/ml). The indirect effect of membrane-bound antibody, i.e. its influence on complement binding by sensitized bystander cells, was examined in a cold target competition assay in which sensitized, non-labelled cells are present when complement is incubated with sensitized labelled cells. We have found that the competitive capacity of sensitized erythrocytes correlated with the amount of membrane-bound immunoglobulins. In accordance with our earlier findings, an equal level of target and competitor cell lysis was obtained only if the fluid phase anti-B antibody concentration was 2 to 4 times higher than that of the anti-A antibodies. We demonstrate in this paper that the different competitive activity of IgM anti-A and anti-B monoclonal antibodies might be accounted for by differences in their C1q and C3 binding capacities.

ABO Blood-Group System↗
PubMed1993

Interactions in the complement-mediated lysis of blood group AB erythrocytes sensitized simultaneously with anti-A and anti-B monoclonal antibodies.

The lysis of group AB erythrocytes by human complement was studied by different anti-A and anti-B IgM monoclonal antibodies (mabs) in a 51Cr-release assay. The concentration of membrane-bound immunoglobulin was detected by ELISA, and the amount of C1q and C3 bound to sensitized red cells was measured by using purified, 125I-labelled molecules. We have demonstrated that there is an exponential relationship between the concentration of the sensitizing IgM mabs and C1q binding to the sensitized AB cell. The efficiency of binding was related to the number of antibodies bound; thus, anti-A sensitized cells bound 3-6 times more C1q than anti-B sensitized cells did. AB cells, on the other hand, bound similar amounts of C3 whether anti-A or anti-B was present. The lytic efficiencies of the various IgM mabs during short incubation times were different, suggesting that the complement activation rates vary widely with different antibodies on the AB cell membrane. The binding of C1q to an antibody-sensitized target activates a cascade, whose components may migrate away from the sensitizing antibody; interactions between the activation processes generated by the anti-A and anti-B antibodies may thus occur. Choosing appropriate pairs of anti-A and anti-B mabs for the simultaneous sensitization of AB cells has indeed resulted in stimulation in some and inhibition in other combinations of mabs. It is suggested that stimulation is observed when the activated intermediates are produced in excess, whereas inhibition occurs when a shortage of activated intermediates prevents mutual utilization.

ABO Blood-Group System↗
PubMed1993

Cardiovascular function and neurologic outcome after cardiac arrest in dogs. The cardiovascular post-resuscitation syndrome.

We studied cardiovascular changes and neurologic outcome at 72 h in 42 healthy dogs after normothermic ventricular fibrillation cardiac arrest (no blood flow) of 7.5, 10, or 12.5 min duration, reversed by standard external cardiopulmonary resuscitation (CPR) (< or = 10 min) and followed by controlled ventilation to 20 h and intensive care to 72 h. We found no difference in resuscitability, mortality, neurologic deficit scores, or overall performance categories between the three insult groups. There was no major pulmonary dysfunction. During controlled normotension post-CPR, all dogs presented a transient reduction in cardiac output. In the 12.5-min cardiac arrest group the decrease in cardiac output persisted beyond 12 h post-CPR (P < 0.01) and was associated with more severe arrhythmias (P < 0.05) and worse morphologic myocardial damage (P < 0.01). Both cardiac and neurologic malfunction at 72 h correlated with arrest time. Only cardiac malfunction correlated with CPR time. Neurologic recovery correlated with mild (inadvertent) pre-arrest hypothermia, diastolic arterial pressure during CPR and absence of cardiovascular impairment at 12 h post-CPR. We conclude that prolonged cardiac arrest in previously healthy dogs is followed by persistent cardiovascular derangements that correlate with impaired neurologic recovery.

Animals↗
PubMed1993

Visceral, hematologic and bacteriologic changes and neurologic outcome after cardiac arrest in dogs. The visceral post-resuscitation syndrome.

We studied the post-resuscitation syndrome in 42 healthy dogs after normothermic ventricular fibrillation cardiac arrest (no blood flow) of 7.5, 10, or 12.5 min duration, reversed by standard external cardiopulmonary resuscitation (CPR) (< or = 10 min) and followed by controlled ventilation to 20 h and intensive care to 72 h. We reported previously, in the same dogs, no difference in resuscitability, mortality, or neurologic outcome between the three insult groups. There was no pulmonary dysfunction, but post-arrest cardiovascular failure, of greater severity in the 12.5 min arrest group. This report concerns renal, hematologic, hepatic and bacteriologic changes. Renal function recovered within 1 h after arrest, without permanent dysfunction. Clotting derangements at 1-24 h postarrest reflect transient disseminated intravascular coagulation with hypocoagulability, more severe after longer arrests, which resolved by 24 h after arrest. Hepatic dysfunction was transient but more severe in the animals that did not recover consciousness and correlated with neurologic dysfunction, but not with brain histologic damage. Bacteremia was present in all animals postarrest. We conclude that in the previously healthy organism after cardiac arrest of 7.5-12.5 min no flow, visceral and hematologic changes, although transient, can retard neurologic recovery.

Amino Acids↗
PubMed1993

Action of natural killer cells and macrophages in cancer.

According to the results obtained in several types of experiments the immunological anti-tumor effects that reflect the clinical situation involve T lymphocytes. The products of natural effector cells can contribute to anti-tumor immunity as part of the cytokine network. In addition, some cytokines can act on the tumor cells by influencing directly their proliferative capacity and/or through modification of their phenotype. In the tumor tissue the interaction between malignant cells and host cells on the one hand, and between the various types of host cells on the other hand, is complex. The participating mechanisms can act in both directions, with the result that the outcome of the balance may be either inhibition or stimulation of tumor growth.

Animals↗
PubMed1993

Carbamazepine (Tegretol)-induced thrombocytopenia.

A case of carbamazepine-induced thrombocytopenia is reported. The patient, a 38-year-old female, developed thrombocytopenia 10 days after receiving 400 mg carbamazepine daily. The presence of an anti-IgG carbamazepine-dependent platelet-reactive antibody was documented. Using flow cytometry, the drug-induced antibody was detected at a drug concentration as low as 10(-6) M.

Adult↗