| Autor: |
Erntell, M., Myhre, E. B., Kronvall, G. |
| Předmět: |
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| Zdroj: |
Scandinavian Journal of Immunology; Mar1983, Vol. 17 Issue 3, p201-209, 9p |
| Abstrakt: |
We tested 140 bacterial strains representing 19 different species for binding of purified radiolabelled F(ab')2 fragments prepared by pepsin digestion of polyclonal and monoclonal human IgG, Both polyclonal and monoclonal F (ab')2 fragments showed positive binding to group C and G streptococci with maximum uptake levels of 50% and 85%. Binding was obtained both with fresh bacteria and with organisms stabilized by heat treatment. F(ab')2 gragments of two human IgG1 myeloma proteins with anti-staphylolysin specificity showed a similar binding pattern. IgG present in normal human serum inhibited the uptake of F(ab')2 fragments, whereas albumin and fibrinogen and purified Fc fragments prepared by papain digestion of polyclonal IgG and monoclonal IgG1 did not show such capacity. Faurteen human myeloma proteins representing IgA, IgM and the four IgG subclasses were tested for inhibiting capacity. Reactivity was noted with at least one mycloma protein within each IgG subclass but not with IgA or with IgM monoclonal proteins. Normal rabbit serum was as inhibitory as normal human scrum, whereas dog serum was less reactive. These data demonstrate that group C and G streptococci carry a heat-stable surface component interacting with the F(ab')2 protion of the IgG molecule. The results suggest that the reactive site on the immunoglobulin molecule may reside in the more constant part of the variable domain. This new reactivity is different from the previously known non-immune reaction involving the IgG Fc portion. This alternative non-immune reactivity is analogous to but distinct from the alternative protein A reaction in Staphylacoccus aureus. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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