484
JOHN E. CUSHING
at temperatures well below those which destroy antibodies, a property
that has been found most useful in demonstrating its distinctive nature.
Other general properties of the system are that it reacts with “all”
antigen-antibody complexes, it is not influenced by immunization, it
maintains relatively constant in uiuo levels, it acts with antibody both
as a bactericidin and cytotoxin, it enhances phagocytosis, and it is much
more efficient in action with yM than with uG antibodies. Many additional attributes of complement reveal it to be an essential and complex
part of the immunological machinery, the activities of which are still
only partially understood. Comparative immunologists therefore are paying increasing attention to it in conjunction with other aspects of the
immunological system.
The complexity of the complement system was long indicated by
the knowledge that it could be inactivated in different ways and reactivated by recombining the inactivated aliquots. For example, heat
inactivated serum regains its activity when combined with zymosan
(prepared from yeast) inactivated serum or with ammonia inactivated
serum. In turn, the latter two serums regain activity when combined.
Classically, four separate components have been recognized through the
inactivation and recombination patterns that were studied. It was also
recognized that the methods involved left much to be desired in terms
of specifying the molecular nature and interactions of components. Some
of these reagents, useful today, are wonderfully bizarre, such as cobra,
Naja naia, venom and that of the brown recluse spider, Luxoceles
reclusa.
The complement story has changed radically over the past few
years. Muller-Eberhard, one of the leading investigators in this area,
has noted that 85% of the references listed in his comprehensive review
(1968) were published within the past 6 years, and 33% of these within
the last 15 months. Present knowledge shows that most of the nine components now known can be characterized in such biochemical detail
that it is predicted that the essential features of the molecular basis of
complement function will be known within the next few years and
that this information will lead to accelerated understanding of the less
well known biological parameters of the system. The details concerning
the complement system are too complex to be presented here, and the
reader is referred to Miiller-Eberhard’s review quoted above, or for
less comprehensive treatments, to the texts of Haurowitz (1968) and
Kabat ( 1968).
An interesting aspect of the complement story are the inherited complement deficiencies now known in guinea pigs, mice, rabbits, and
humans. These show that direct and “simple” genetic relationships exist
JOHN E. CUSHING
at temperatures well below those which destroy antibodies, a property
that has been found most useful in demonstrating its distinctive nature.
Other general properties of the system are that it reacts with “all”
antigen-antibody complexes, it is not influenced by immunization, it
maintains relatively constant in uiuo levels, it acts with antibody both
as a bactericidin and cytotoxin, it enhances phagocytosis, and it is much
more efficient in action with yM than with uG antibodies. Many additional attributes of complement reveal it to be an essential and complex
part of the immunological machinery, the activities of which are still
only partially understood. Comparative immunologists therefore are paying increasing attention to it in conjunction with other aspects of the
immunological system.
The complexity of the complement system was long indicated by
the knowledge that it could be inactivated in different ways and reactivated by recombining the inactivated aliquots. For example, heat
inactivated serum regains its activity when combined with zymosan
(prepared from yeast) inactivated serum or with ammonia inactivated
serum. In turn, the latter two serums regain activity when combined.
Classically, four separate components have been recognized through the
inactivation and recombination patterns that were studied. It was also
recognized that the methods involved left much to be desired in terms
of specifying the molecular nature and interactions of components. Some
of these reagents, useful today, are wonderfully bizarre, such as cobra,
Naja naia, venom and that of the brown recluse spider, Luxoceles
reclusa.
The complement story has changed radically over the past few
years. Muller-Eberhard, one of the leading investigators in this area,
has noted that 85% of the references listed in his comprehensive review
(1968) were published within the past 6 years, and 33% of these within
the last 15 months. Present knowledge shows that most of the nine components now known can be characterized in such biochemical detail
that it is predicted that the essential features of the molecular basis of
complement function will be known within the next few years and
that this information will lead to accelerated understanding of the less
well known biological parameters of the system. The details concerning
the complement system are too complex to be presented here, and the
reader is referred to Miiller-Eberhard’s review quoted above, or for
less comprehensive treatments, to the texts of Haurowitz (1968) and
Kabat ( 1968).
An interesting aspect of the complement story are the inherited complement deficiencies now known in guinea pigs, mice, rabbits, and
humans. These show that direct and “simple” genetic relationships exist