THE CELLULAR BASIS FOR IMMUNITY 
IN MALARIA 
By WILLIAM H. TALIAFERRO 
DEPARTMENT OP BACTERIOLOGY AND PARASITOLOGY, THE UNIVERSITY OP CHICAGO, CHICAGO, ILL. 
There are four main aspects of the func¬ 
tional role of cells in malarial immunity: 
(1) the phagocytosis by various leucocytes 
and, in particular, by macrophages of para¬ 
sites and other materials incident upon the 
infection; (2) the production of new phago¬ 
cytes; (3) various reparative proliferations 
other than the production of phagocytes; 
and (4) the elaboration of specific anti- 
parasitic antibodies. Of these the first 
three are of importance in both natural and 
acquired immunity and can be studied di¬ 
rectly in histological preparations. The 
fourth is the specific characteristic of ac¬ 
quired immunity and has not been studied 
in malaria. In fact, it has only been in¬ 
vestigated under the most favorable con¬ 
ditions by indirect methods which have 
given plausible but not conclusive results. 
The literature on these and related sub¬ 
jects is so voluminous that it can be only 
treated summarily with comparatively few 
references to specific investigations. It has 
been critically reviewed in detail by Tali¬ 
aferro and Mulligan (1937). 
In considering the physical basis for 
malarial immunity, it should be kept in 
mind that the defense reactions against any 
infectious agent are fundamentally the 
same. The distinguishing characteristics of 
malarial immunity arise largely from the 
localization of the parasite in the blood 
stream, since such a localization determines 
where the parasites will come in contact 
with phagocytic cells (see Taliaferro 1934). 
Detailed studies on the cellular basis for 
immunity in the malarias of man are handi¬ 
capped in the following ways (Cannon, this 
volume p. 214). Most human necropsy 
material represents terminal stages of the 
infection in which the defense mechanisms 
of the host have been broken down. Most 
of the work has been done on infections of 
P. falciparum in which various degenera¬ 
tive manifestations have overshadowed the 
defense aspects. Studies on monkeys indi¬ 
cate that certain cardinal aspects of the 
immune process last for only a short time 
and are generally missed unless the experi¬ 
mental hosts are sacrificed at closely spaced 
intervals. Finally, much of the human 
material has not been fixed immediately 
after death and handled with the special¬ 
ized techniques necessary for the finer 
cytological details which are important in 
studying the histogenesis of macrophages. 
Much of the underlying theoretical part of 
the following account is, therefore, based 
on simian malaria with as many facts as 
possible fitted in from the literature on 
human infections; 
Cells Involved in Immunity 
Ordinarily, malarial parasites are intro¬ 
duced parenterally through the epidermis 
so that there is no opportunity for the 
manifold nonspecific factors, such as epi¬ 
thelial barriers, the outward flow of mucous 
or urine, or the action of digestive fluids, 
to come into play as they do in natural 
immunity to some potential invaders. 
The cells chiefly involved in inflamma¬ 
tion and the so-called defense reactions 
against parenterally introduced materials 
belong to the connective tissue which is 
derived embryologically from the mesen¬ 
chyme. The connective tissue includes the 
blood and lymph, the reticular or blood- 
forming tissues, loose connective and adi¬ 
pose tissues, cartilage and bone and per¬ 
forms a wide variety of physiological func¬ 
tions including respiration, intermediate 
metabolism, storage and various types of 
mechanical support. Of these various com¬ 
ponents, the cells most active in immunity 
belong to the blood and lymph and the 
