PubMed Health⌕ Search

Biomedical subjects

M W Cunningham

Publications and source records attributed to M W Cunningham.

At least 55 records · Page 3Linked to original sources
PubMed1994

Pathogenicity of the hookworm, Ancylostoma pluridentatum, in a Florida panther (Felis concolor coryi) kitten.

We evaluated clinical signs and administered anthelmintic treatment to a wild-caught, captive Florida panther (Felis concolor coryi) kitten from Big Cypress National Preserve, Florida (USA) infected with the hookworm, Ancylostoma pluridentatum. Clinical signs observed included poor body condition, lethargy, and below normal red blood cell numbers, hemoglobin concentration, and packed cell volume, and elevated eosinophil numbers. In addition, a maximum of 936 Ancylostoma sp. eggs/g of feces were found on Day 11 of captivity. Following oral administration of 20 mg/kg pyrantel pamoate on Day 11, 26 A. pluridentatum were collected from the feces. Based on the resolution of clinical signs, cessation of egg shedding, and a return to normal hematologic values following anthelmintic treatment, we believe that infection with A. pluridentatum was the primary cause of the stressed conditions in the panther kitten.

Administration, Oral↗
PubMed1993

A subset of mouse monoclonal antibodies cross-reactive with cytoskeletal proteins and group A streptococcal M proteins recognizes N-acetyl-beta-D-glucosamine.

It is well known that antibodies to N-acetyl-beta-D-glucosamine (GlcNAc) cross-react with cardiac valves, skin, and other host tissues. However, molecular targets of these antibodies have not been identified. For this reason, anti-streptococcal mAb cross-reactive with group A streptococci and heart proteins were studied for their reactivity with GlcNAc, the immunodominant epitope of group A streptococcal carbohydrate. Characterization of the mAb that recognized GlcNAc revealed that each mAb had its own unique antigen-binding profile and pattern of immunofluorescence on rat heart cells. In the ELISA and Western blot these mAb reacted with cytoskeletal and heart proteins such as actin, keratin, myosin, and vimentin, as well as with streptococcal recombinant M5 and M6 proteins. Binding of the mAb to cytoskeletal proteins was inhibited by GlcNAc conjugated with BSA in a dose-dependent manner, and the mAb preferentially reacted with high-density GlcNAc-BSA conjugates. Antigenic determinants on the proteins recognized by the mAb were resistant to sodium periodate and N-acetylglucosaminidase treatment, suggesting reactivity with peptide and not carbohydrate structures. On reaction of the mAb with a panel of synthetic streptococcal, viral, and myosin peptides, one of the mAb, 49.8.9, was found to react most strongly with a synthetic peptide sequence synthesized from the coxsackievirus B3 capsid protein VP1, which shows homology with and cross-reacts with sequences in the streptococcal M6 protein and human cardiac myosin. This most interesting mAb, previously shown to neutralize coxsackie viruses, recognized the amino acid sequence RRKLEFF, which may mimic the GlcNAc epitope. The data collected show that we have identified a new group of multireactive autoantibodies that recognize GlcNAc and cytoskeletal proteins, as well as defined peptide epitopes.

Acetylglucosamine↗
PubMed1993

Role of heavy chain constant domains in antibody-antigen interaction. Apparent specificity differences among streptococcal IgG antibodies expressing identical variable domains.

In this report, we examine the influence of CH domains on antibody specificity, in the context of variable epitope density on bacteria and synthetic glycoconjugates. Hybridomas secreting IgG1 and IgG2b mAb, specific for the N-acetyl-glucosamine (GlcNAc) residues of streptococcal group A carbohydrate, were previously generated from a hybridoma secreting a mouse IgG3 mAb. We show that these three mAb have identical H and L chain V domains, as determined by 1) cDNA sequencing, 2) binding to soluble Ag, and 3) binding to nine monoclonal anti-idiotopes. Nevertheless, the IgG3 mAb binds more effectively than the V region-identical IgG1 or IgG2b mAb to each of three strains of group A streptococci that display different amounts of terminal GlcNAc residues on their cell walls. The magnitude of the subclass-associated differential in binding varies with the target strain, and, whereas the IgG3 mAb binds best to the strain expressing an intermediate amount of GlcNAc, the IgG1 and IgG2b mAb and IgG3-derived F(ab')2 fragments bind best to the strain expressing the highest amount of GlcNAc. The IgG3 mAb also binds better than the IgG1 and IgG2b mAb to solid-phase GlcNAc50-BSA, but the IgG2b mAb binds best to otherwise identical conjugates with lower ratios of GlcNAc to BSA (20:1, 10:1, 5:1, and 1:1). These results suggest that epitope density can significantly influence the magnitude of IgG subclass-associated binding differences, and that structural differences in the CH regions, particularly the CH2 and CH3 domains, can influence the apparent specificities of IgG molecules for multivalent Ag.

Acetylglucosamine↗
PubMed1993

Poststreptococcal anti-myosin antibody idiotype associated with systemic lupus erythematosus and Sjögren's syndrome.

Anti-myosin antibodies are found in acute rheumatic fever (ARF), a sequela of group A streptococcal infection. An antiidiotypic serum was produced that was specific for idiotopes expressed by anti-myosin antibodies in ARF (anti-My1). Studies indicated that idiotypic determinants detected with this serum were present in anti-myosin antibodies and absent from normal human immunoglobulins that lacked specificity for myosin. Anti-My1 was tested against sera from patients with other types of autoimmune diseases as well as uncomplicated streptococcal infections. Sera from systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), and poststreptococcal acute glomerulonephritis patients demonstrated idiotypic reactivity with anti-My1. Affinity-purified anti-myosin antibodies from SLE, SS, and ARF sera also reacted strongly with anti-My1, indicating that immunoglobulins produced in these diseases share idiotypic determinants. The data demonstrated an association of the My1 idiotype with poststreptococcal sequelae and the two autoimmune diseases SLE and SS.

Autoantibodies↗
PubMed1993

Restricted immunoglobulin VH usage and VDJ combinations in the human response to Haemophilus influenzae type b capsular polysaccharide. Nucleotide sequences of monospecific anti-Haemophilus antibodies and polyspecific antibodies cross-reacting with self antigens.

To examine the human antibody repertoire generated against a biologically significant antigen we have obtained sequences of heavy chain variable region genes (IgVH) from 15 monoclonal antibodies specific for the capsular polysaccharide of Haemophilus influenzae type b (Hib PS). All VH segments are members of the VH3 family and 9 of 15 are members of the smaller VH3b subfamily. Restriction is evident by the shared use of certain VDJ joints in independent hybridomas from different subjects. Two hybridomas generated from the same subject demonstrate identical heavy chain variable region gene sequences but differ in isotype and rearrange alternative light chain variable region genes (IgVL), suggesting that in a normal immune response, a single pre-B cell clone may use different light chain rearrangements and give rise to progeny capable of reacting with antigen. Using a polymerase chain reaction assay optimized to detect base pair differences among VH genes we demonstrate that at least a portion of expressed anti-Hib PS VH genes have undergone somatic mutation. Anti-Hib PS heavy chain genes are homologous to VH segments encoding autoantibodies and two hybridomas secrete anti-Hib PS antibody that cross-reacts with self antigens (double-stranded DNA and single-stranded DNA). Comparison of VH regions of self-reactive and monospecific anti-Hib PS Ab demonstrates no consistent structural feature correlating with fine antigen specificity. These data demonstrate significant restriction in VH usage and VDJ recombination in the anti-Hib PS response and confirm that autoantibodies may be elicited during normal immune responses.

Amino Acid Sequence↗
PubMed1992

Cytotoxic and viral neutralizing antibodies crossreact with streptococcal M protein, enteroviruses, and human cardiac myosin.

The development of autoimmunity in certain instances is related to infectious agents. In this report, cytotoxic monoclonal antibodies (mAbs) that recognize epitopes on both enteroviruses and the bacterium Streptococcus pyogenes are described. Murine anti-streptococcal mAbs that were crossreactive with streptococcal M protein, human cardiac myosin, and other alpha-helical coiled-coil molecules were found to neutralize coxsackieviruses B3 and B4 or poliovirus type 1. The viral-neutralizing anti-streptococcal mAbs were also cytotoxic for heart and fibroblast cell lines and reacted with viral capsid proteins on a Western immunoblot. Alignment of amino acid sequences shared between streptococcal M protein, coxsackie-virus B3 capsid protein VP1, and myosin revealed 40% identity in a 14- to 15-amino acid overlap. Synthetic peptides containing these sequences blocked mAb reactivity with streptococcal M protein. The data show that antibodies against alpha-helical structures of bacterial and viral antigens can lead to cytotoxic reactions and may be one mechanism to explain the origin of autoimmune heart disease.

Amino Acid Sequence↗
PubMed1992

Evidence for actinlike proteins in an M protein-negative strain of Streptococcus pyogenes.

Antigens shared between Streptococcus pyogenes and heart tissue may play an important role in autoimmune cardiac injury associated with acute rheumatic fever. Antiheart/antistreptococcal antibodies found in the disease react with antigens of S. pyogenes, including M protein and a 60-kDa antigen distinct from M protein. Heart antigens recognized by these cross-reactive antistreptococcal antibodies include myosin and actin. To investigate the presence of a streptococcal actin, established protocols for the polymerization and isolation of eukaryotic actin were used to extract and concentrate actinlike proteins from M- streptococcal cells. The polymerized bacterial actin from the streptococcal extract was probed in immunoblots with an antiactin monoclonal antibody. Two proteins of about 60 kDa in the polymerized bacterial actin reacted with the antiactin antibody. Proteins in the polymerized bacterial actin extract of about 43 and 60 kDa behaved like eukaryotic actin by binding to myosin and DNase I affinity columns. Filaments were demonstrated by electron microscopy in the polymerized bacterial actinlike extract, which also enhanced the ATPase activity of eukaryotic myosin. The data suggest that proteins resembling actin are present in S. pyogenes.

Actins↗
PubMed1991

Anti-Coxsackievirus B3 neutralizing antibodies with pathological potential.

Adolescent CD-1 mice inoculated with coxsackievirus B3 (CVB3m) will develop acute myocarditis with focal lesions by 7 days post-inoculation (p.i.). Administration of murine sera containing anti-CVB3m-neutralizing antibodies into CVB3m-inoculated mice at 3 days p.i. will exacerbate myocarditis, suggesting the presence of pathological antibodies. To study potential pro-inflammatory properties of virus-induced antibodies, a panel of anti-CVB3m-neutralizing monoclonal antibodies (mAbs) was generated. Several studies demonstrated shared epitopes between CVB3m particles and cultured murine cardiac or neonatal skin fibroblasts: (1) one or more mAbs bound to cultured cardiac fibroblasts; (2) several mAbs can participate in complement-mediated lysis of neonatal skin fibroblasts; and (3) at least one mAbs stimulated synthesis of a macrophage chemoattractant from cultured neonatal skin fibroblasts. Injection of one mAb in three doses, each of about 5 micrograms, into adolescent male CD-1 mice induced focal myocarditic lesions which were similar to CVB3m-induced lesions. One mAb induced a diffuse interstitial hypercellularity in most mice and two mAbs did not induce detectable cardiopathology. These data suggest that some anti-CVB3m neutralizing idiotypes (antibodies) which initially can provide protection via virus clearance mechanisms can also bind to cross-reacting epitopes on normal tissues. Binding of antibodies to normal heart tissues could stimulate proinflammatory reactions by several mechanisms and sustain myocarditis.

Animals↗
PubMed1991

Autoimmune determinants of rheumatic carditis: localization of epitopes in human cardiac myosin.

Rheumatic carditis is a sequela of group A streptococcal throat infection. Although the pathogenic mechanisms which lead to heart damage in acute rheumatic fever (ARF) are not well understood, autoimmune processes have been implicated, involving molecular mimicry between streptococci and the human heart. We have studied the immunological cross-reactions between the group A Streptococcus and human heart to understand their molecular and immunological basis. Human and mouse monoclonal antibodies (mAb) and affinity-purified anti-myosin antibodies from acute rheumatic fever sera were characterized and shown to cross-react with group A streptococcal M protein and myosin. Studies of proteolytic fragments of human cardiac myosin identified sites of cross-reactivity in the rod region of the myosin heavy chain. Murine monoclonal antibodies cross-reactive with streptococcal M protein and myosin recognized epitopes located in the S2 and light meromyosin (LMM) subfragments of the heavy chain. None of the cross-reactive monoclonal antibodies recognized the S1 subfragment. One broadly cross-reactive monoclonal antibody was highly cytotoxic for heart cells in vitro and reactive with the LMM fragment. The data suggest that the cross-reactive epitopes recognized by these antibodies are conformational, dependent upon their alpha-helical structures, and potentially damaging to host tissues.

Antigens, Bacterial↗
PubMed1991

Immunoreactivity of anti-streptococcal monoclonal antibodies to human heart valves. Evidence for multiple cross-reactive epitopes.

Association of group A streptococci with acute rheumatic fever and valvular heart disease is well established; however the basis of valve injury remains unclear. In this study, anti-streptococcal monoclonal antibodies (MAbs) cross-reactive with myocardium were reacted with sections from 22 rheumatic valves, nine normal, five endocarditic, one 'floppy,' and one Marfan valve. In immunohistochemical studies, MAb reactivity was observed with cardiac myocytes, smooth muscle cells, cell surface and cytoplasm of endothelial cells lining valves, and valvular interstitial cells. Endothelial basement membrane and elastin fibrils reacted with the MAbs, whereas collagen was unreactive. Similar reactivity was seen with sera from acute rheumatic fever patients. The anti-streptococcal MAbs reacted with intravalvular myosin and vimentin in Western blots, and purified elastin competitively inhibited the binding of the anti-streptococcal MAbs to whole group A streptococci. The data show that human heart valves have numerous sites of immunoreactivity with anti-streptococcal MAbs and acute rheumatic fever sera of potential importance in the pathogenesis of rheumatic valvular injury.

Adult↗
PubMed1990

A new heart-cross-reactive antigen in Streptococcus pyogenes is not M protein.

To identify tissue-cross-reactive antigens other than M protein in Streptococcus pyogenes, proteins of M-positive strains and an M-negative strain were probed in Western blots for reactivity with cross-reactive streptococcal monoclonal antibodies (MAbs) 36.2.2 and 54.2.8. A protein(s) near a molecular mass of 60 kDa in extracts of five group A streptococcal serotypes and the M-negative strain reacted with the MAbs. A study of human antibody responses to purified membranes of S. pyogenes indicated a hyperreactivity to a 60-kDa protein in acute rheumatic fever. Since MAbs 36.2.2 and 54.2.8 are known to cross-react with myosin or actin and streptococcal M protein, the data suggest that a homology or conformation is shared between the 60-kDa antigen and M protein. Therefore, the 60-kDa antigen is a new heart- or tissue-cross-reactive antigen of S. pyogenes that shares immunologic epitopes with but is distinct from M protein.

Acute Disease↗
PubMed1989

Human and murine antibodies cross-reactive with streptococcal M protein and myosin recognize the sequence GLN-LYS-SER-LYS-GLN in M protein.

Molecular mimicry or epitope similarity between group A streptococcal M proteins and myosin may contribute to the presence of heart reactive antibodies in acute rheumatic fever. In our study overlapping synthetic peptides copying the entire sequence of PepM5 protein were used to map the myosin cross-reactive epitopes of streptococcal M protein recognized by mouse and human mAb and affinity purified myosin-specific antibodies from acute rheumatic fever and rheumatic heart disease sera. Overlapping M protein peptides SM5(164-197)C and SM5(184-197)C inhibited the murine mAb reactions with PepM5 protein. The human mAb and affinity purified myosin-specific antibodies reacted exclusively with SM5(184-197)C. However, one of the five different purified myosin-specific antibodies not only reacted with SM5(184-197)C but also reacted with SM5(84-116)C. The synthetic subpeptides SM5(175-184)C and SM5(188-197C) did not react with any of the antibodies to PepM5 and myosin demonstrating a requirement of the 184-188 amino acid sequence for antibody recognition. A heptapeptide containing the sequence SM5(183-189) was also found to inhibit selected human myosin-specific antibodies and a human antimyosin mAb. Therefore, the majority of mouse and human myosin crossreactive antibodies recognized an epitope within the 14 residue carboxy terminus of PepM5 which appeared to involve the GLN-LYS-SER-LYS-GLN sequence.

Amino Acid Sequence↗
PubMed1989

Tropomyosin shares immunologic epitopes with group A streptococcal M proteins.

Tropomyosin is an alpha-helical coiled-coil protein with structural similarities to the streptococcal M protein. In order to show serologic cross-reactivity between streptococcal M proteins and tropomyosin, we selected from a panel of murine mAb those which reacted with M proteins and tropomyosins in the ELISA. Western blots were used to study the reactions of each mAb with human and rabbit cardiac and rabbit skeletal tropomyosins. The antibodies were further characterized for their reactions with the additional autoantigens myosin, actin, keratin, and DNA. Five mAb were found which reacted with either PepM5 or ColiM6 protein and tropomyosin in Western blots or ELISA. Two of the tropomyosin positive mAb were also antinuclear antibodies and were inhibited with DNA. In Western blots of cardiac tropomyosins, the mAb reacted with either the 70-kDa dimer of tropomyosin, the 35-kDa monomer, or both. Some differences were observed in the reactions of the mAb with the different tropomyosins in Western blots. The heart cross-reactive epitopes shared between M proteins and tropomyosin were in most instances shared with cardiac myosin. Differences were observed among the reactions of the mAb with the different tropomyosins. This report constitutes the first evidence of serologic cross-reactivity between streptococcal M proteins and tropomyosins.

Amino Acid Sequence↗
PubMed1988

Human monoclonal antibodies reactive with antigens of the group A Streptococcus and human heart.

Human mAb were produced from tonsillar or PBL of normal individuals or patients infected with group A streptococci. Lymphocytes were purified on Ficoll-Hypaque gradients and stimulated in vitro with purified group A streptococcal membranes or M protein extracts. The mAb were selected for study based on their reaction with group A streptococci, pep M5 protein, and/or M6 Escherichia coli protein. Further analysis by Western immunoblot or competitive inhibition ELISA revealed that there were two types of antibodies: one type that reacted with myosin and DNA and the other type that reacted with myosin, keratin, and/or actin. The specificities of these human mAb are similar to specificities observed in our previous studies of murine mAb reactive with group A streptococci and heart Ag. For comparison, anti-myosin antibodies were affinity purified from the sera of infected or acute rheumatic fever patients and were shown to react with myosin and DNA as well as with group A streptococci and M protein. To affinity purify these antibodies from normal sera, five times the amount of sera was required to obtain detectable quantities. These data suggest that the human mAb reactive with group A streptococci and myosin reflect the antibodies seen in sera from infected patients or acute rheumatics and that the B lymphocyte clones capable of producing these cross-reactive antibodies are also present in normal individuals.

Antibodies, Bacterial↗
PubMed1988

Heart cross-reactive antigens of mutans streptococci share epitopes with group A streptococci and myosin.

Monoclonal antibodies (mAb) generated by immunization of mice with membranes of Streptococcus pyogenes Manfredo (M type 5) were tested for their reactivity with sodium dodecyl sulfate extracts of Streptococcus mutans GS5, Streptococcus rattus BHT (formerly S. mutans, serotype b), and S. mutans Ingbritt 175 in the Western blot. The reaction of the sodium dodecyl sulfate-extracted proteins of whole S. mutans, serotype b), and S. rattus with the mAb revealed that the shared cross-reactive antigens were near m.w. 62,000 to 67,000. Several higher m.w. proteins in S. mutans Ingbritt 175 reacted with the mAb but were not observed in the other two strains of streptococci. Cytoplasmic membranes of S. rattus BHT reacted with these mAb in the enzyme-linked immunosorbent assay and Western blot. The most reactive BHT membrane component detected by these mAb was a 62-kDa polypeptide that was similar in m.w. to the membrane component recognized by these antibodies in purified S. pyogenes membranes. The reactivity of the mAb with BHT membranes in the enzyme-linked immunosorbent assay was absorbed by rabbit skeletal muscle myosin. The patterns of reactivity observed in the BHT membrane immunoblots in this study closely resemble those previously obtained using polyclonal rabbit anti-human heart sera.

Antibodies, Monoclonal↗
PubMed1988

Recombinant human interleukin 2 (rIL-2) enhancement of antibody production by human-human hybridomas.

We studied the effect of highly purified recombinant interleukin 2 from Escherichia coli (rIL-2) on antibody production by our human hybridomas. Increasing concentrations of rIL-2 were directly related to increased production of immunoglobulin, which reached peak levels of 13-25 micrograms/ml, a 10- to 20-fold increase over untreated hybridomas. We were unable to demonstrate large quantities of the IL-2 receptor on the hybridomas as measured by an anti-TAC monoclonal antibody. The data suggest that the antibody enhancement phenomenon is mediated by IL-2 and that is a new, effective way to achieve higher levels of immunoglobulin from human hybridomas.

Antibodies, Bacterial↗