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E Haas

Publications and source records attributed to E Haas.

At least 19 recordsLinked to original sources
PubMed2005

Fast collapse but slow formation of secondary structure elements in the refolding transition of E. coli adenylate kinase.

The various models proposed for protein folding transition differ in their order of appearance of the basic steps during this process. In this study, steady state and time-resolved dynamic non-radiative excitation energy transfer (FRET and trFRET) combined with site specific labeling experiments were applied in order to characterize the initial transient ensemble of Escherichia coli adenylate kinase (AK) molecules upon shifting conditions from those favoring denaturation to refolding and from folding to denaturing. Three sets of labeled AK mutants were prepared, which were designed to probe the equilibrium and transient distributions of intramolecular segmental end-to-end distances. A 176 residue section (residues 28-203), which spans most of the 214 residue molecule, and two short secondary structure chain segments including an alpha-helix (residues 169-188) and a predominantly beta-strand region (residues 188-203), were labeled. Upon fast change of conditions from denaturing to folding, the end-to-end distance of the 176 residue chain section showed an immediate collapse to a mean value of 26 A. Under the same conditions, the two short secondary structure elements did not respond to this shift within the first ten milliseconds, and retained the characteristics of a fully unfolded state. Within the first 10 ms after changes of the solvent from folding to denaturing, only minor changes were observed at the local environments of residues 203 and 169. The response of these same local environments to the shift of conditions from denaturing to folding occurred within the dead time of the mixing device. Thus, the response of the CORE domain of AK to fast transfer from folding to unfolding conditions is slow at all three conformational levels that were probed, and for at least a few milliseconds the ensemble of folded molecules is maintained under unfolding conditions. A different order of the changes was observed upon initiation of refolding. The AK molecules undergo fast collapse to an ensemble of compact structures where the local environment of surface probes seems to be native-like but the two labeled secondary structure elements remain unfolded.

Adenylate Kinase↗
PubMed2005

Pericallosal aneurysm simulating corpus callosum tumour.

The MRI characteristics of an isolated subacute aneurysmal corpus callosum hematoma, without evidence of blood in cerebrospinal fluid (CSF) spaces or ventricles, have not been previously reported. This report highlights the difficulty of accurate diagnosis and treatment in a patient with an unusual ruptured pericallosal aneurysm simulating a corpus callosum tumour. Additionally we analyse the particular radiological configuration and appearance of blood products in this region.

Adult↗
PubMed2005

Characterization of an infectious cDNA copy of the genome of a naturally occurring, avirulent coxsackievirus B3 clinical isolate.

Group B coxsackieviruses (CVB) cause numerous diseases, including myocarditis, pancreatitis, aseptic meningitis and possibly type 1 diabetes. To date, infectious cDNA copies of CVB type 3 (CVB3) genomes have all been derived from pathogenic virus strains. An infectious cDNA copy of the well-characterized, non-pathogenic CVB3 strain GA genome was cloned in order to facilitate mapping of the CVB genes that influence expression of a virulence phenotype. Comparison of the sequence of the parental CVB3/GA population, derived by direct RT-PCR-mediated sequence analysis, to that of the infectious CVB3/GA progeny genome demonstrated that an authentic copy was cloned; numerous differences were observed in coding and non-coding sequences relative to other CVB3 strains. Progeny CVB3/GA replicated similarly to the parental strain in three different cell cultures and was avirulent when inoculated into mice, causing neither pancreatitis nor myocarditis. Inoculation of mice with CVB3/GA protected mice completely against myocarditis and pancreatitis induced by cardiovirulent CVB3 challenge. The secondary structure predicted for the CVB3/GA domain II, a region within the 5' non-translated region that is implicated as a key site affecting the expression of a cardiovirulent phenotype, differs from those predicted for cardiovirulent and pancreovirulent CVB3 strains. This is the first report characterizing a cloned CVB3 genome from an avirulent strain.

5' Untranslated Regions↗
PubMed2004

Combined minimal invasive techniques in deep supratentorial intracerebral haematomas.

Minimal invasive techniques (MIT) like microscopy, stereotaxy, endoscopy and neuronavigation facilitate and improve neurosurgical results and reduce the operative trauma. We report the combined employment of these techniques and the results obtained in our department during the last 7 years in 95 consecutive patients with supratentorial deep located intracerebral haematomas (ICHs). Thirty-six deteriorating patients with deep ICHs under 30 cm (3) volume associated to intraventricular bleeding, were treated early (first 24 hours after bleeding) with neuronavigation guided stereotactic lysis, using multiplanar targets (1 to 3). Microsurgical clot aspiration through an enlarged burr-hole was frequently combined with endoscope- or neuronavigation-assisted evacuation within the first 6 hours after bleeding for the rest of the deteriorating patients with ICHs larger than 30 cm (3). A 1.2 cm narrow surgical corridor assured the least injury to vital cortical areas, tracts and blood vessels. In 86 cases the clots were adequately removed (non-measurable rest) with a reduced morbid mortality (13.8 and 8.6 as well as 23.3 and 16.9 for stereotactic and microscopic MIT, respectively). In our experience, the use of combined MIT adapted to the surgical urgency of the individual patient reduces the operative trauma and improves the accuracy for the access to the clot allowing an adequate haematoma evacuation and a satisfactory outcome in most of the cases.

Adult↗
PubMed2003

Minimal invasive neurosurgery of infiltrative tumours extending around the sellar region: advantage of combined methods.

Most of the infiltrative tumoural lesions located around the sellar region compromise the cavernous sinus, cranial nerves, vascular neighboured structures and the hypothalamus. Minimal invasive neurosurgery (MIN) employing microsurgery, neuroendoscopy, neuronavigation and intraoperative radioscopy are reported to increase gross total tumour resection reducing the operative trauma. We combined at least 3 of these techniques in 32 patients with solid and 8 patients with cystic tumours of this region. Thirty tumours were approached in a transphenoidal manner, ten were via a single burr hole craniotomy in a transcortico-ventricular approach. In 36 cases the tumours were adequately removed with only six cases suffering a transitory and one with a permanent deterioration of a preoperatively diagnosed neurological deficit. In our experience, the use of combined techniques, particularly in these patients, reduces the operative trauma and improves the accuracy in planning the access, angle and extension of tumour removal. It also protects the patient from secondary damage to neighboured structures.

Adult↗
PubMed2002

The natively helical chain segment 169-188 of Escherichia coli adenylate kinase is formed in the latest phase of the refolding transition.

The refolding transition of Escherichia coli adenylate kinase (AK) was investigated by monitoring the refolding kinetics of a selected 20 residue helical segment in the CORE domain of the protein. Residues 169 and 188 were labeled by 1-acetamido-methyl-pyrene, and by bimane, respectively. The experiment combines double-jump stopped-flow fast mixing initiation of refolding and time-resolved Förster energy transfer spectroscopy for monitoring the conformational transitions (double-kinetics experiment). Two kinetic phases were found in the denaturant-induced unfolding of AK. In the first phase, the fluorescence quantum yields of both probes decreased. The distribution of the distances between them transformed from the native state's narrow distribution with the mean distance corresponding to the distance in the crystal structure, to a distribution compatible with an unordered structure. In the second, slow step of denaturation, neither the fluorescence parameters of the probes nor the distance distribution between them changed. This step appeared to be a transformation of the fast-folding species formed in the first phase, to the slow-folding species. Refolding of the fast-folding species of the denatured state of AK was also a two-phase process. During the first fast phase, within less than 5ms, the fluorescence emission of both probes increased, but the distance distribution between the labeled sites was unchanged. Only during the second slow refolding step did the intramolecular distance distribution change from the characteristic of the denatured state to the narrow distribution of the native state. This experiment shows that for the case of the CORE domain of AK, the large helical segment of residues 169-188 was not formed in the first compaction step of refolding. The helical conformation of this segment is established only in the second, much slower, refolding phase, simultaneously with the completion of the native structure.

Adenylate Kinase↗
PubMed2001

Structure and dynamics of the alpha-lactalbumin molten globule: fluorescence studies using proteins containing a single tryptophan residue.

The fluorescence properties of three variants of alpha-lactalbumin (alpha-LA) containing a single tryptophan residue were investigated under native, molten globule, and unfolded conditions. These proteins have levels of secondary structure and stability similar to those of the wild type. The fluorescence signal in the native state is dominated by that of W104, with the signal of W60 and W118 significantly quenched by the disulfide bonds in their vicinity. In the molten globule state, the magnitude of the fluorescence signal of W60 and W118 increases, due to the loss of rigid, specific side chain packing. In contrast, the magnitude of the signal of W104 decreases in the molten globule state, perhaps due to the protonation of H107 or quenching by D102 or K108. The solvent accessibilities of individual tryptophan residues were investigated by their fluorescence emission maximum and by acrylamide quenching studies. In the native state, the order of solvent accessibility is as follows: W118 > W60 > W104. This order changes to W60 > W104 > W118 in the molten globule state. Remarkably, the solvent accessibility of W118 in the alpha-LA molten globule is lower than that in the native state. The dynamic properties of the three tryptophan residues were examined by time-resolved fluorescence anisotropy decay studies. The overall rotation of the molecule can be observed in both the native and molten globule states. In the molten globule state, there is an increase in the extent of local backbone fluctuations with respect to the native state. However, the fluctuation is not sufficient to result in complete motional averaging. The three tryptophan residues in the native and molten globule states have different degrees of motional freedom, reflecting the folding pattern and dynamic heterogeneity of these states. Taken together, these studies provide new insight into the structure and dynamics of the alpha-LA molten globule, which serves as a prototype for partially folded proteins.

Amino Acid Substitution↗
PubMed2001

A permissive role for tumor necrosis factor in vascular endothelial growth factor-induced vascular permeability.

Vascular endothelial growth factor (VEGF) induces both angiogenesis and an increase in vascular permeability, 2 processes that are considered to be important for both tumor growth and the delivery of drugs to the site of tumors. This study demonstrates that transmembrane expression of tumor necrosis factor (tmTNF) is up-regulated in the endothelium of a murine methylcholanthrene (meth A)-induced sarcoma in comparison to the adjacent normal dermal vasculature and is also present on cultivated human endothelial cells. It is further shown that tmTNF is required for VEGF-mediated endothelial hyperpermeability in vitro and in vivo. This permissive activity of TNF appears to be selective, because anti-TNF antibodies ablated the VEGF-induced permeability but not proliferation of cultivated human endothelial cells. Furthermore, tnf gene-deficient mice show no obvious defects in vascularization and develop normally but failed to respond to administration of VEGF with an increase in vascular permeability. Subsequent studies indicated that the tmTNF and VEGF signaling pathways converge at the level of a secondary messenger, the "stress-activated protein kinase-2" (SAPK-2)/p38: (1) up-regulated endothelial expression of tmTNF resulted in the continuous activation of SAPK-2/p38 in vitro, and (2) an inhibitor of SAPK-2/p38 activation abolished the vascular permeability activity of VEGF in vivo. In conclusion, the study's finding that continuous autocrine signaling by tmTNF sensitizes endothelial cells to respond to VEGF by increasing their vascular permeability provides new therapeutic concepts for manipulating vascular hyperpermeability.

Animals↗
PubMed2001

A diverse family of proteins containing tumor necrosis factor receptor-associated factor domains.

We have identified three new tumor necrosis factor-receptor associated factor (TRAF) domain-containing proteins in humans using bioinformatics approaches, including: MUL, the product of the causative gene in Mulibrey Nanism syndrome; USP7 (HAUSP), an ubiquitin protease; and SPOP, a POZ domain-containing protein. Unlike classical TRAF family proteins involved in TNF family receptor (TNFR) signaling, the TRAF domains (TDs) of MUL, USP7, and SPOP are located near the NH(2) termini or central region of these proteins, rather than carboxyl end. MUL and USP7 are capable of binding in vitro via their TDs to all of the previously identified TRAF family proteins (TRAF1, TRAF2, TRAF3, TRAF4, TRAF5, and TRAF6), whereas the TD of SPOP interacts weakly with TRAF1 and TRAF6 only. The TD of MUL also interacted with itself, whereas the TDs of USP7 and SPOP did not self-associate. Analysis of various MUL and USP7 mutants by transient transfection assays indicated that the TDs of these proteins are necessary and sufficient for suppressing NF-kappaB induction by TRAF2 and TRAF6 as well as certain TRAF-binding TNF family receptors. In contrast, the TD of SPOP did not inhibit NF-kappaB induction. Immunofluorescence confocal microscopy indicated that MUL localizes to cytosolic bodies, with targeting to these structures mediated by a RBCC tripartite domain within the MUL protein. USP7 localized predominantly to the nucleus, in a TD-dependent manner. Data base searches revealed multiple proteins containing TDs homologous to those found in MUL, USP7, and SPOP throughout eukaryotes, including yeast, protists, plants, invertebrates, and mammals, suggesting that this branch of the TD family arose from an ancient gene. We propose the moniker TEFs (TD-encompassing factors) for this large family of proteins.

Amino Acid Sequence↗
PubMed2001

A randomized and prospective study comparing treatment with high-dose intravenous immunoglobulin with monoclonal antibodies for rescue of kidney grafts with steroid-resistant rejection.

BACKGROUND: The aim of this study was to compare the effectiveness of intravenous immunoglobulin (IVIg) versus monoclonal anti-CD3 as a treatment for steroid-resistant rejections. From January 1995 to June 1997, 30 patients were analyzed. They were randomized into two groups. Resistant rejections were diagnosed by core biopsy. Group A received 500 mg/ kg/day IVIg (Sandoglobulin) for 7 consecutive days, whereas group B received 5 mg/day of OKT3 for 14 consecutive days. Daily T cell CD3+ peripheral count was performed for 14 days for group B. The immunosuppression was similar for both groups. Cyclosporine was stopped during both treatments. METHODS: Demographic factors, HLA mismatch, creatinine levels before and after treatment, and the incidence of rejections after treatment (up to 1 month) were taken into account for this study. RESULTS: Data from different samples were compared using Fisher's exact test. Graft and patient survival were analyzed using the Kaplan-Meier method. The were no significant differences found in age, graft origin, HLA mismatch, or time of follow-up until the episode of rejection. Success was achieved for 11 (73.3%) of 15 of group A and 13 (86.6%) of 15 of group B (P=0.79). Creatinine levels before and after treatment were as follows: A, 2.99+/-1.30 mg/dl and 2.1+/-0.70 mg/dl versus B, 3.1+/-1.1 mg/dl and 2.5+/-0.8 mg/dl. Besides, we did not observe differences in the creatinine 1 month after treatment (A: 2.35+/-0.78 mg/dl; B: 2.51+/-1.10 mg/dl; P=0.66) nor in the third month (A: 1.83+/-0.58 mg/dl; B: 2.30+/-0.89 mg/dl; P=0.24). The incidence of rejections after treatment was 5 (46%) of 11 for group A and 9 (75%) of 12 for group B (P=0.4). The patient survival rates 2 years after treatment were 87 and 92% for A and B groups, respectively. Graft survival was identical (80% in both groups). CONCLUSION: Should the favorable result presented in this report be confirmed in larger number of patients, IVIg could become the preferable choice of rejection treatment for steroid-resistant rejection because of a complete absence of the unwanted side effects commonly associated with OKT3.

Adolescent↗
PubMed2001

Local and long-range interactions in the thermal unfolding transition of bovine pancreatic ribonuclease A.

This research was undertaken to distinguish between local and global unfolding in the reversible thermal denaturation of bovine pancreatic ribonclease A (RNase A). Local unfolding was monitored by steady-state and time-resolved fluorescence of nine mutants in each of which a single tryptophan was substituted for a wild-type residue. Global unfolding was monitored by far-UV circular dichroism and UV absorbance. All the mutants (except F8W and D38W) exhibited high specific enzymatic activity, and their far-UV CD spectra were very close to that of wild-type RNase A, indicating that the tryptophan substitutions did not affect the structure of any of the mutants (excluding K1W and Y92W) under folding conditions at 20 degrees C. Like wild-type RNase A, the various mutants exhibited reversible cooperative thermal unfolding transitions at pH 5, with transition temperatures 2.5-11 degrees C lower than that of the wild-type transition, as detected by far-UV CD or UV absorbance. Even at 80 degrees C, well above the cooperative transition of all the RNase A mutants, a considerable amount of secondary and tertiary structure was maintained. These studies suggest the following two-stage mechanism for the thermal unfolding transition of RNase A as the temperature is increased. First, at temperatures lower than those of the main cooperative transition, long-range interactions within the major hydrophobic core are weakened, e.g., those involving residues Phe-8 (in the N-terminal helix) and Lys-104 and Tyr-115 (in the C-terminal beta-hairpin motif). The structure of the chain-reversal loop (residues 91-95) relaxes in the same temperature range. Second, the subsequent higher-temperature cooperative unfolding transition is associated with a loss of secondary structure and additional changes in the tertiary contacts of the major hydrophobic core, e.g., those involving residues Tyr-73, Tyr-76, and Asp-38 on the other side of the molecule. The hydrophobic interactions of the C-terminal loop of the protein are enhanced by high temperature, and perhaps are responsible for the preservation of the local structural environment of Trp-124 at temperatures slightly above the major cooperative transition. The results shed new light on the thermal unfolding transitions, generally supporting the thermal unfolding hypothesis of Burgess and Scheraga, as modified by Matheson and Scheraga.

Amino Acid Substitution↗
PubMed2001

Distributions of intramolecular distances in the reduced and denatured states of bovine pancreatic ribonuclease A. Folding initiation structures in the C-terminal portions of the reduced protein.

The purpose of this investigation is to characterize the reduced state of RNase A (r-RNase A) in terms of (i) intramolecular distances, (ii) the sequence of formation of stable loops in the initial stages of folding, and (iii) the unfolding transitions induced by GdnHCl. This is accomplished by identifying specific subdomain structures and local and long-range interactions that direct the folding process of this protein and lead to the native fold and formation of the disulfide bonds. Eleven pairs of dispersed sites in the RNase A molecule were labeled with fluorescent donor and acceptor probes, and the distributions of intramolecular distances (IDDs) were determined by means of time-resolved dynamic nonradiative excitation energy transfer (TR-FRET) measurements. The mutants were designed to search for (a) a possible nonrandom fold of the backbone in the collapsed state and (b) possible loops stabilized by long-range interactions. It was found that, under folding conditions, (i) the labeled mutants of r-RNase A in refolding buffer (the R(N) state) exhibit features of specific (nonrandom) compact but very dispersed subdomain structures (indicated by short mean distances, broad IDDs, and a weak dependence of the mean distances on segment length), (ii) the backbone fold in the C-terminal beta-like portion of the molecule appears to adopt a native-like overall fold, (iii) the N-terminal alpha-like portion of the chain is separated from the C-terminal core by very large intramolecular distances, larger than those in the crystal structure, and (iv) perturbations by addition of GdnHCl reveal several conformational transitions in different sections of the chain. Addition of GdnHCl to the native disulfide-intact protein provided a reference state for the extent of expansion of intramolecular distances under denaturing conditions. In conclusion, r-RNase A under folding conditions (the R(N) state) is poised for the final folding step(s) with a native-like trace of the chain fold but a large separation between the two subdomains which is then decreased upon introduction of three of the four native disulfide cross-links.

Animals↗
PubMed2000

Inhibition of death receptor-mediated gene induction by a cycloheximide-sensitive factor occurs at the level of or upstream of Fas-associated death domain protein (FADD).

In HeLa cells, induction of apoptosis and nuclear factor kappaB (NF-kappaB) activation initiated by TRAIL/Apo2L or the agonistic Apo1/Fas-specific monoclonal antibody anti-APO-1 require the presence of cycloheximide (CHX). Inhibition of caspases prevented TRAIL/anti-APO-1-induced apoptosis, but not NF-kappaB activation, indicating that both pathways bifurcate upstream of the receptor-proximal caspase-8. Under these conditions, TRAIL and anti-APO-1 up-regulated the expression of the known NF-kappaB targets interleukin-6, cellular inhibitor of apoptosis 2 (cIAP2), and TRAF1 (TRAF, tumor necrosis factor receptor-associate factor). In the presence of CHX, the stable overexpression of a deletion mutant of the Fas-associated death domain molecule FADD comprising solely the death domain of the molecule but lacking its death effector domain (FADD-(80-208)) led to the same response pattern as TRAIL or anti-APO-1 treatment. Moreover, the ability of death receptors to induce NF-kappaB activation was drastically reduced in a FADD-deficient Jurkat cell line. TRAIL-, anti-APO-1-, and FADD-(80-208)-initiated gene induction was blocked by a dominant-negative mutant of TRAF2 or the p38 kinase inhibitor SB203580, similar to tumor necrosis factor receptor-1-induced NF-kappaB activation. CHX treatment rapidly down-regulated endogenous cFLIP protein levels, and overexpression of cellular FLICE inhibitory protein (cFLIP) inhibited death receptor-induced NF-kappaB activation. Thus, a novel functional role of cFLIP as a negative regulator of gene induction by death receptors became apparent.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Determination of intramolecular distance distribution during protein folding on the millisecond timescale.

A method for determination of transient (on the millisecond timescale) intramolecular distance distributions (IDDs) by time-resolved dynamic non-radiative excitation energy transfer measurements was developed. The time-course of the development of the IDD between residues 73 and 203 in the CORE domain of Escherichia coli adenylate kinase throughout refolding from the GuHCl-induced denatured state was determined. The mean of the apparent IDD reduced to a value close to its magnitude in the native protein, within 2 ms (the dead-time of the instrument). At that time the width of that distribution was rather large (16+/-2 A). The large width implies that the intramolecular diffusion coefficient of the labeled segment does not exceed 10(-7) cm(2)/second. In a second slower phase of the refolding transition, the width was reduced to its native value (6+/-4 A).

Adenylate Kinase↗
PubMed2000

[Modification of postoperative wound healing by showering].

Usually postoperative wounds are kept dry until the stitches are removed. In a prospective randomized study early water contact was allowed in order to test postoperative wound healing in 817 patients operated on for varicose veins. Regardless of whether the wounds were kept dry or had water contact with or without shower foam from the second postoperative day, no infection was registered.

Adult↗
PubMed1999

Continuous autotropic signaling by membrane-expressed tumor necrosis factor.

Tumor necrosis factor (TNF) exists in two bioactive forms, the membrane-integrated form and the proteolytically derived soluble cytokine. Cells that produce TNF are often responsive to TNF, allowing autocrine/juxtacrine feedback loops. However, whether the membrane form of TNF is involved in such regulatory circuits is unclear. Here we demonstrate that HeLa cells, expressing a permanently membrane-integrated mutant form of TNF, constitutively express TNF.TNF receptor complexes at their cell surface. These cells show a permanent activation of the transcription factor NF-kappaB, exert constitutive p38 mitogen-activated protein kinase activity, and produce high amounts of interleukin-6. In parallel, transmembrane TNF-expressing HeLa cells display high sensitivity to cycloheximide or interferon-gamma, similar to untransfected cells treated with these agents in combination with sTNF. Moreover, cycloheximide-induced apoptosis in transmembrane TNF transfectants can be blocked by the caspase inhibitor zVAD-fmk and does not necessarily need cell to cell contact, indicating a critical role of constitutive autotropic signaling of TNF.TNF receptor complexes. These data demonstrate that autotropic signaling loops of membrane TNF can exist, which may be of importance for cells that express both TNF and TNF receptors, such as T lymphocytes, macrophages, and endothelial cells.

Amino Acid Chloromethyl Ketones↗
PubMed1999

Role of the 75-kDa TNF receptor in TNF-induced activation of neutrophil respiratory burst.

The exclusive role of the 55-kDa TNF receptor (TNF-R55) as the signaling receptor in TNF-induced activation of respiratory burst by human polymorphonuclear leukocytes residing on biologic surfaces has been inferred from results obtained with receptor-specific monoclonal and polyclonal Abs. In this work, we confirm this assumption by a more direct approach, i.e., by using receptor-specific TNF mutants (p55TNF and p75TNF) and, as a novel contribution, we show that cooperation of the 75-kDa TNF receptor (TNF-R75) is required for a full blown response to the cytokine. This conclusion stems from three sets of data: 1) none of the TNF-R55-specific agonists used, i.e., mAbs or p55TNF, induced a respiratory burst comparable with that induced by TNF; 2) selective down-modulation of TNF-R75 resulted in a diminished response to TNF but not to TNF-R55-specific agonists or to the chemotactic peptide FMLP; and 3) mAbs that either block or stabilize binding of TNF to TNF-R75 inhibited the response to the cytokine, suggesting that cooperation requires not only TNF binding to the receptor but also an appropriate dissociability from it. The inhibitory effect of the Abs increased as the cytokine concentrations decreased, indicating that cooperation by TNF-R75 becomes more relevant at low TNF doses. Such a cooperation does not seem to rely on the activation of a TNF-R75-linked signaling pathway independent of TNF-R55, since the response to p55TNF and p75TNF given in combination was not higher than the response to p55TNF alone. The possible mechanisms of cooperation are discussed.

Antigens, CD↗