Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “epitopes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1999

MHC class I-restricted epitope spreading in the context of tumor rejection following vaccination with a single immunodominant CTL epitope.

Epitope spreading is a process whereby epitopes distinct from and non-cross-reactive with an inducing epitope become targets of an evolving immune response. This phenomenon has been associated most notably with the progression of naturally occurring or experimentally induced chronic autoimmune diseases. We have investigated the potential occurrence of epitope spreading in the context of antitumor cytotoxic T cell (CTL) responses using chicken ovalbumin (OVA) as a model antigen. Our results indicate that following rejection of OVA-expressing EG.7 tumor cells effectuated by a CTL response which is induced against the MHC class I-restricted immunodominant epitope OVA257-264, there occurs intramolecular diversification of the CTL response to two additional OVA-derived epitopes, OVA176-183 and OVA55-62, as well as intermolecular spreading to other endogenous tumor-derived determinants. It seems that CTL-mediated tumor cell destruction in vivo favors cross-presentation of additional epitopes with the consequent activation of additional tumor-reactive lymphocytes. The process of epitope spreading in that context has obvious important implications for the design of antigen-specific antitumor immunotherapies.

Animals↗
PubMed2006

Epitope mapping of full-length glycoprotein D from HSV-2 reveals a novel CD4+ CTL epitope located at the transmembrane-cytoplasmic junction.

The glycoprotein D of HSV-2 (gD2) is currently a leading candidate vaccine target for genital herpes vaccines as both cellular and humoral responses can be generated against it. However, little is known about how vaccine composition will affect T cell epitope selection. A panel of 15-mer peptides (with 11 amino acid overlap) spanning full-length gD2 was used to investigate the fine specificity of T cell responses to gD2 as well as the role of vaccine composition on epitope selection. Spleen cells from BALB/c mice (H-2(d)) immunized with gD2, formulated with or without AlPO(4) and/or IL-12, were stimulated in vitro with overlapping gD2 peptides. Cellular responses (lymphoproliferation and IFN-gamma expression) were mapped to four epitopes within the gD2 molecule: gD2(49-63), gD2(105-119), gD2(245-259), and gD2(333-347). CTL analysis of these four epitopes indicated that not all of them could serve as a CTL epitope. Mice immunized with gD2 expressed from a viral vector mounted CTL responses primarily to one epitope located in the extracellular domain of gD2 (gD2(245-259)). More importantly, mice immunized with gD2 co-administered with IL-12 mounted CTL responses to an additional epitope located at the transmembrane-cytoplasmic junction of gD2 (gD2(333-347)). The location of this novel epitope emphasizes the benefit of using full-length versions of glycoproteins when designing vaccine components.

Amino Acid Sequence↗
PubMed2003

T cell epitope identification for bovine vaccines: an epitope mapping method for BoLA A-11.

T cell responses play an important role in immunity to parasites and other microbial agents of infectious diseases, therefore a number of T cell-directed vaccines are in development. Computer-driven algorithms that facilitate the discovery of T cell epitopes from protein and genome sequences are now being used to accelerate preclinical studies of human vaccines. Similar tools are not yet available for predicting T cell epitopes for animal vaccines, but there may be sufficient data available to begin the process of compiling the algorithms. We describe the construction of a novel mathematical 'matrix' that describes the properties of bovine major histocompatibility complex (BoLA) system antigen (BoLA) A-11 peptide ligands, developed for use with EpiMatrix, an existing T cell epitope-mapping algorithm. An alternative means of developing BoLA matrices, using the pocket profile method, is also discussed. Matrices such as the one described here may be used to develop T cell epitope-mapping tools for cattle and other ruminants. Epitope-mapping algorithms offer a significant advantage over other methods of epitope selection, such as the screening of synthetic overlapping peptides, because high throughput screening can be performed in silico, followed by ex vivo confirmatory studies. Furthermore, using epitope-mapping algorithms, putative T cell epitopes can be derived directly from genomic sequences, allowing researchers to circumvent labor-intensive cloning steps in the genome-to-vaccine discovery pathway.

Algorithms↗
PubMed1995

T-cell epitopes of Phl p 1, major pollen allergen of timothy grass (Phleum pratense): evidence for crossreacting and non-crossreacting T-cell epitopes within grass group I allergens.

BACKGROUND: The use of peptides representing T-cell epitopes of allergens is a modern concept for improvement of specific immunotherapy. A prerequisite for this approach is the identification of T-cell epitopes of atopic allergens. METHODS: T-cell lines and 40 T-cell clones (TCC) specific for Phl p 1, the group I allergen of timothy grass (Phleum pratense), were established from the peripheral blood of nine patients allergic to grass pollen and mapped for epitope specificity by using overlapping dodecapeptides. Phenotype and cytokine production profile of TCC were investigated. Representative TCC were analyzed for HLA-restriction, T-cell receptor V beta gene usage, and crossreactivity with grass pollen extracts from Dactylis glomerata, Poa pratensis, Lolium perenne, Secale cereale, and selected amino acid sequence-derived peptides. RESULTS: Patients displayed IgE binding to all grass species investigated. Forty TCC were established. Fifteen T-cell epitopes could be identified on Phl p 1. Of 40 TCC, 39 displayed the helper cell (Th) phenotype; one clone was CD8+. Specific stimulation induced a Th2-like type of cytokine production in 20 of 39 TCC. Crossreactivity studies revealed crossreacting and non-crossreacting T-cell epitopes. CONCLUSION: Phl p 1, a major grass pollen allergen, harbors multiple T-cell epitopes. Species-specific and crossreacting T-cell epitopes exist among group I allergens of grasses. Epitope recognition patterns could not be correlated with particular HLA haplotypes. A restricted T-cell receptor V beta gene usage was not observed.

Allergens↗
PubMed1995

Interaction between a Fab fragment against gp41 of human immunodeficiency virus 1 and its peptide epitope: characterization using a peptide epitope library and molecular modeling.

The molecular interaction of the Fab fragment of the human monoclonal antibody 3D6, directed against the transmembrane protein gp41 of human immunodeficiency virus (HIV) 1, with its peptide epitope is characterized by a panel of overlapping peptides, a peptide epitope library and molecular modeling techniques. The sequence CSGKLICTTAVPW, corresponding to amino acids 605-617 of gp41, was identified as the best binding peptide (KD = 1 x 10(-8) mol/l). This peptide served as a starting point to prepare a cellulose-bound peptide epitope library in which each residue of the epitope is substituted by all L- and D-amino acids, resulting in 494 epitope peptide variants which were subsequently analyzed for binding 3D6. The library was synthesized to identify residues critical for binding and to obtain information about the molecular environment of the epitope peptide bound to 3D6. Both cysteine residues, as well as isoleucine 6, threonine 8 and proline 12, of the epitope were highly sensitive to substitution. Using the data obtained from the epitope characterization, as well as a low-resolution electron density map of a 3D6 Fab-peptide complex, a 3-D model of the Fab-peptide complex was generated by molecular modeling. The modeling experiments predict binding of the peptide, which is cyclized via the two cysteine residues, to a pocket formed dominantly by the hypervariable loops complementarity determining regions CDR3L, CDR2H and CDR3H.

Amino Acid Sequence↗
PubMed2004

Anaplasma marginale major surface protein 2 CD4+-T-cell epitopes are evenly distributed in conserved and hypervariable regions (HVR), whereas linear B-cell epitopes are predominantly located in the HVR.

Organisms in the genus Anaplasma express an immunodominant major surface protein 2 (MSP2), composed of a central hypervariable region (HVR) flanked by highly conserved regions. Throughout Anaplasma marginale infection, recombination results in the sequential appearance of novel MSP2 variants and subsequent control of rickettsemia by the immune response, leading to persistent infection. To determine whether immune evasion and selection for variant organisms is associated with a predominant response against HVR epitopes, T-cell and linear B-cell epitopes were localized by measuring peripheral blood gamma interferon-secreting cells, proliferation, and antibody binding to 27 overlapping peptides spanning MSP2 in 16 cattle. Similar numbers of MSP2-specific CD4(+) T-cell epitopes eliciting responses of similar magnitude were found in conserved and hypervariable regions. T-cell epitope clusters recognized by the majority of animals were identified in the HVR (amino acids [aa] 171 to 229) and conserved regions (aa 101 to 170 and 272 to 361). In contrast, linear B-cell epitopes were concentrated in the HVR, residing within hydrophilic sequences. The pattern of recognition of epitope clusters by T cells and of HVR epitopes by B cells is consistent with the influence of protein structure on epitope recognition.

Anaplasma marginale↗
PubMed2006

Influence of sequential oligopeptide carriers on the bioactive structure of conjugated epitopes: comparative study of the conformation of a Herpes simplex virus glycoprotein gD-1 epitope in the free and conjugated form, and protein "built-in" crystal structure.

Synthetic carriers play an important role in immunogen presentation, due to their ability of inducing improved and specific responses to conjugated epitopes. Their influence on the bioactive conformation of the epitope, though admittedly crucial for relevant in vitro and in vivo applications, is difficult to evaluate, given the usual lack of information on the complex conformational features determined by the nature of the carrier and the mode of ligation. Using the Herpes simplex virus glycoprotein D-1 epitope (Leu(9)-Lys-Nle-Ala-Asp-Pro-Asn-Arg-Phe-Arg-Gly-Lys-Asp-Leu(22)) as a model, we have performed a detailed conformational analysis on the free epitope peptide in solution and on three constructs in which the epitope was conjugated to sequential oligopeptide carriers {Ac-[Lys-Aib-Gly](4)-OH (SOC(4))} (through either a thioether or an amide bond; Ac: acetyl) and polytuftsin oligomers {H-[Thr-Lys-Pro-Lys-Gly](4)-NH(2) (T20)}, (through a thioether bond). The analysis of the epitope conformation in the parent protein, in carrier-conjugated and free form, suggests that the beta-turn structure of the -Asp(13)-Pro-Asn-Arg(16)- segment is highly conserved and independent of the epitope form. However, small conformational variations were observed at the C-terminal part of the epitope, depending on the nature of the carrier.

Amino Acid Sequence↗
PubMed1994

Grafting of a hepatitis B S-preS(2) T-cell epitope on lysozyme enhances the immunogenicity of lysozyme in responder mice primed with the T-cell epitope.

Subunit immunogens composed of well-defined T- and B-cell epitopes might represent a valuable approach to design vaccines. The reduction of the size of the T-cell epitope is clearly in the line of this strategy. In this study we evaluated the capacity of a hepatitis B S-preS(2) surface antigen-derived T-cell epitope (i.e., S2b) to enhance the humoral immune response towards lysozyme when covalently linked to this antigen. We hereby anticipated that new problems, related to processing of a subunit immunogen, may emerge when grafting minimalized T-cell epitopes on protein antigens. Indeed, insertion of a T-cell epitope containing peptide (i.e., S2b) in a new protein context does not warrant a correct processing of the T-cell epitope. To avoid such potential processing problems an acid labile linker between T-cell and B-cell epitopes was devised in order to provide a processing-independent cleavage site. Using a T-cell hybridoma specific for the S2b T-cell epitope the S2bC-lysozyme conjugate was found to be presented by functional antigen-presenting cells. However, fixed APC did not present the conjugate in vitro indicating that processing is required for the release and presentation of S2b. The ability of the conjugate to generate an enhanced immune response was investigated in vivo. In S2b-primed mice the S2bC-lysozyme conjugate was found to elicit a faster and higher anti-lysozyme humoral response, as compared to uncoupled mixtures of lysozyme and S2b.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1996

Mapping of an autoreactive epitope within glutamate decarboxylase using a diabetes-associated human monoclonal autoantibody and an epitope cDNA library.

Glutamate decarboxylase (GAD65) is a major autoantigen in insulin-dependent diabetes (IDDM) and the neurological disorder Stiff-Man-Syndrome (SMS). We derived a human monoclonal autoantibody (MICA 2) from peripheral blood of a patient newly diagnosed with IDDM, which reacted with GAD65 in Western blots. This indicated that a linear epitope is recognized by MICA 2. Using an epitope cDNA library we mapped the MICA 2 epitope to a contiguous stretch of 26 amino acids (506-531) in the C-terminus of GAD65. Neither blocking experiments with synthetic peptides nor analysis of overlapping decapeptides expressed as fusion proteins allowed us to further narrow down the epitope to the typical size of linear epitopes of 6-8 amino acids. We suggest that a miniconformational epitope provided by amino acids 506-531 is recognized by MICA 2, which withstands SDS gel electrophoresis without destruction or partially refolds during the Western blot procedure. A sequence homology with human heat shock protein 60 (HSP60) maps to this region of GAD65 but no cross-reactivity of MICA 2 with HSP60 occurred. Our data demonstrate that reactivity of an antibody in Western blots does not necessarily define a classic linear epitope of 6-8 amino acids and describe a new autoreactive epitope in GAD65 different from those reported for sera from patients with SMS.

Amino Acid Sequence↗
PubMed1992

Monoclonal antibody epitopes of mycobacterial 65-kD heat-shock protein defined by epitope scanning.

The binding sites for MoAbs to the 65-kD heat-shock protein (hsp65) of mycobacteria have been investigated by epitope scanning. Five hundred and twenty-six 8-mer peptides representing the complete sequence of Mycobacterium tuberculosis hsp65 were synthesised in duplicate using the Epitope Scanning Kit (CRB Ltd.). The epitopes of six MoAbs raised to the hsp65 of M. tuberculosis or M. leprae were investigated. We have identified the epitope of a new MoAb (DC16); this epitope is continuous, hydrophilic in nature and 11 amino acids long. We have also confirmed the location of the epitopes of three MoAbs (IIH9, ML30 and IIC8). Thus the epitope scanning technique has proved suitable for the detection of continuous epitopes of hsp65.

Amino Acid Sequence↗
PubMed1992

Antigenic structure of the herpes simplex virus type 1 glycoprotein C: demonstration of a linear epitope situated in an environment of highly conformation-dependent epitopes.

A continuous epitope, situated within or in close proximity to antigenic site II of the herpes simplex virus type 1-specified glycoprotein C (gC-1), was identified. The continuous linear nature of the epitope, defined by a monoclonal antibody C2H12, was established by three independent lines of evidence: (i) The epitope was detectable by immunoblot under denaturing and reducing conditions. (ii) The epitope was detectable by RIPA of extracts from TM-treated HSV-infected cells, despite the malfolding caused by this treatment. (iii) The epitope was detected in an approximately 5,000-dalton papain fragment of gC-1. A mapping analysis, primarily based on use of mutant virus, expressing truncated gC-1 molecules, suggested that the mapping position of the epitope was delimited by amino acids 120 and 230. Other epitopes of this region of gC-1 are highly conformation-dependent, and the existence of a linear epitope, accessible on native gC-1, may facilitate the elucidation of the functional anatomy of gC-1.

Antibodies, Monoclonal↗
PubMed2005

Identification of novel human CTL epitopes and their agonist epitopes of mesothelin.

PURPOSE: Mesothelin is overexpressed in many pancreatic and ovarian cancers, mesotheliomas, and other tumor types. Clinical trials are ongoing using immunotoxins to target mesothelin, and patients immunized with allogeneic pancreatic tumor cell lines have shown immune responses to previously defined mesothelin epitopes. The purpose of this study was to define novel mesothelin CTL epitopes and, more importantly, agonist epitopes that would more efficiently activate human T cells to more efficiently lyse human tumors. EXPERIMENTAL DESIGN AND RESULTS: Two novel mesothelin HLA-A2 epitopes were defined. T-cell lines generated from one of these epitopes were shown to lyse pancreatic and ovarian tumor cells. Several agonist epitopes were defined and were shown to (a) have higher affinity and avidity for HLA-A2, (b) activate mesothelin-specific T cells from normal individuals or cancer patients to a greater degree than the native epitope in terms of induction of higher levels of IFN-gamma and the chemokine lymphotactin, and (c) lyse several mesothelin-expressing tumor types in a MHC-restricted manner more effectively than T cells generated using the native peptide. External beam radiation of tumor cells at nontoxic levels was shown to enhance the expression of mesothelin and other accessory molecules, resulting in a modest but statistically significant increase in tumor cell lysis by mesothelin-specific T cells. CONCLUSIONS: The identification of novel CTL agonist epitopes supports and extends observations that mesothelin is a potential target for immunotherapy of pancreatic and ovarian cancers, as well as mesotheliomas.

Carcinoma, Squamous Cell↗
PubMed1998

Definition of multiple ICA512/phogrin autoantibody epitopes and detection of intramolecular epitope spreading in relatives of patients with type 1 diabetes.

The related tyrosine phosphatase-like proteins, islet cell antigen 512 (ICA512) and phosphatase homologue in granules of insulinoma (phogrin), are major targets of autoantibodies in patients with type 1 diabetes. In the current study, we have examined the overlapping specificities and antigenic epitopes of autoantibodies to ICA512 and phogrin and determined whether intramolecular epitope spreading occurs during the development of diabetic autoimmunity. ICA512 autoantibodies and phogrin autoantibodies were detected in 65-70% (n = 110) of patients with new-onset type 1 diabetes and 60-65% (n = 42) of prediabetic relatives of patients with type 1 diabetes. Of the sera, 10% reacted with ICA512 but not phogrin, whereas only 1% of sera reacted with phogrin but not ICA512. The binding of phogrin autoantibodies in 88 dual (ICA512 and phogrin) autoantibody-positive sera could be completely blocked by excess recombinant ICA512, whereas the blocking of ICA512 autoantibodies with recombinant phogrin was only partial (mean inhibition of 58.9 +/- 3.7%, mean +/- SE). Binding and competition analysis using multiple chimeric ICA512/phogrin constructs demonstrated that a major unique epitope for ICA512 autoantibodies is localized to amino acids 762-887. A conformational epitope associated with the carboxy-terminal 31 amino acids of ICA512 was recognized by one-third of sera, and a minor epitope is located on amino acids 601-762 of ICA512. The major epitopes for phogrin-selective autoantibodies were localized to amino acids 640-922 of phogrin. Sequential serum samples were analyzed in 22 relatives who expressed ICA512/phogrin autoantibodies. Intramolecular epitope spreading was found for 5 of 13 relatives who have progressed to type 1 diabetes. Among nine relatives who have remained nondiabetic, three demonstrated a decrease in the number of epitopes recognized. These studies highlight the complexity of autoantibody recognition of ICA512/phogrin and are consistent with the hypothesis that ICA512/phogrin may be recognized as a consequence of beta-cell destruction.

Adolescent↗
PubMed1988

Identification of phosphorylcholine epitope-containing antigens in Brugia malayi and relation of serum epitope levels to infection status of jirds with brugian filariasis.

The Gib 13 monoclonal antibody was raised against eggs of Onchocerca gibsoni and subsequently found to react with a phosphorylcholine epitope designated as the T15 idiotype. Since an immunoradiometric assay based on the Gib 13 monoclonal antibody holds promise for serodiagnosis of filariasis, the goals of the current study were to evaluate phosphorylcholine epitope production and release by various parasite stages and to assess changes in serum epitope levels during different phases of Brugia malayi infection in jirds. Extracts of B. malayi adult male worms, female worms, and microfilariae contained Gib 13 monoclonal antibody-reactive antigens of Mr 25-30,000, 57-90,000, and approximately equal to 200,000. Adult female worms secreted ten-fold more epitope than microfilariae on a weight basis. Phosphorylcholine-containing antigens were localized in female and male worms, respectively, in egg-bearing regions and the intestines. Assessment of the relationship between serum levels of Gib 13 antibody-binding epitope and parasitologic status of B. malayi-infected jirds showed that the immunoradiometric assay distinguishes patent infected from uninfected control animals, detects a significant rise in epitope level during the prepatent phase of infection, and is unaffected by diethylcarbamazine-induced reduction in the intensity of microfilaremia. There was a direct positive correlation between serum epitope level and female adult worm load. Quantification of serum phosphorylcholine epitope of the T15 idiotype may be useful as an indirect measure of parasite burden in humans with lymphatic filariasis that is independent of microfilaremia.

Animals↗
PubMed2005

[Identification of HTNV-NP-specific T lymphocyte epitopes and analysis of the epitope-specific T cell response].

AIM: To identify the nucleocapsid protein of Hantaan virus (HTNV-NP)-specific T lymphocyte epitopes and analyze the epitope-specific T cell response during hemorrhagic fever with renal syndrome (HFRS). METHODS: T lymphocyte epitopes and frequencies of epitope-specific T cells were determined by ELISPOT using PBMCs from HFRS patients stimulated by individual or mixture of overlapping 15-mer peptides spanning the amino acid sequence of HTNV-NP. RESULTS: Out of 10 peptide mixtures, 8 elicited strong HTNV-NP-specific responses in 18 of 47 HFRS patients, and the T cell response was found at early stage of HFRS. Moreover, 17 HTNV-NP-specific T lymphocyte epitopes were identified in 11 patients, and most epitopes were clustered near the center of NP in linear structure. Among them, 14 T lymphocyte epitopes were described for the first time. CONCLUSION: HTNV-NP-specific T cell response can be elicited at early stage of HFRS and T lymphocyte epitopes mainly located in the center of NP, suggesting that it may play an important role in immune protection during HTNV infection.

Adolescent↗
PubMed2006

Epitope mapping of anti-alpha-fodrin autoantibody in juvenile Sjögren's syndrome: difference in major epitopes between primary and secondary cases.

OBJECTIVE: Juvenile Sjögren's syndrome (SS) is an early-onset type of SS. Autoantibody against the N-terminal 120 kDa form of a-fodrin is a specific and sensitive disease marker for both juvenile and adult SS. We investigated the initial and major determinants of a-fodrin in SS. METHODS: Sera were obtained from patients with juvenile SS, 10 with primary SS and 10 with secondary SS. Epitope specificities of IgG antibodies were examined by dot-blot analyses using overlapping fusion proteins of the N-terminal part (561 amino acid residues) of a-fodrin as antigens. RESULTS: All sera from patients with primary SS reacted with amino acid residues 1 to 98 and 36 to 150, but not with 91 to 199. Epitope mapping using fusion proteins with subfragments, each consisting of about 50 amino acid residues, showed reactivity with amino acid residues 27-80 and 79-132, suggesting that at least 2 epitopes are contained in the first 150 amino acid residues. All 3 cases with neurological complications had additional epitope specificities. Sera from patients with secondary SS showed more diversified specificities and strongly reacted with amino acid residues 1-98 and 334-432, whereas the reactivities to 36-150, a major epitope in primary SS, were minimal. CONCLUSION: Major and initial B cell epitopes specifically reside in N-terminal amino acids 36-132 and could be used as a diagnostic tool for primary SS. The epitope subsequently expands to other regions of a-fodrin in association with the development of neurological complications or disease progression. Secondary SS has distinct epitope specificities.

Adolescent↗
PubMed1985

T cell clones to two major T cell epitopes of myoglobin: effect of I-A/I-E restriction on epitope dominance.

The murine T cell response to sperm whale myoglobin was analyzed for polyclonal and monoclonal T cells. For polyclonal T cells, the immunodominant epitope included residue Glu 109 when the antigen-presenting cells expressed I-Ad, whereas a Lys 140-containing epitope was immunodominant when the antigen-presenting cells expressed I-Ed only. Monoclonal T cells specific for each epitope were derived from a polyclonal line. T cell clones specific for the Glu 109 epitope were restricted to I-Ad, whereas the clones specific for the Lys 140 epitope were restricted to I-Ed. Thus, for an antigen that can be presented in association with either I-Ad or I-Ed, the immunodominance of particular epitopes depends strongly on the restriction element used. The immunodominance of each epitope-Ia combination may be due to a limited repertoire of T cells or selective presentation of epitope and Ia by accessory cells.

Animals↗
PubMed1977

Immune response against two epitopes on the same thymus-independent polysaccharide carrier. 1. Role of epitope density in carrier-dependent immunity and tolerance.

Immunogenicity and tolerogenicity of two epitopes (alpha 1-6 and FITC) on the same dextran B 512 carrier were investigated. The following conclusions were made: (1) Both epitopes were thymus-independent and immunogenic and tolerogenic as well. (2) The marked dose differences between the two epitopes with regard to tolerance induction were found to be a consequence of the affinity and the heterogeneity of the responding B cells as well as the epitope density employed for detecting the PFC in a predictable way. (3) The alpha 1-6 response, in contrast to the anti-FITC response, was homogeneous and of low affinity and the number of precursor B cells was low. (4) Different mouse strains were found to be high-, low- or non-responders to alpha 1-6, but all the strains tested responded to the FITC epitope coupled to dextran. (5) Dextran and FITC-dextran were polyclonal B cell activators in the strains tested, irrespective of their ability to respond to the alpha 1-6 epitope. The findings indicate that epitope density and mol. wt of the immunogen as well as Ig receptor affinity for the epitope on the B cells are variables which markedly influence the binding of the immunogen to the specific B cells and therefore affect the delivery of the non-specific triggering signal.

Animals↗