ABSTRACT
I. Introduction 3
II. Rhinovirus 4
III. Host Defense Against Rhinovirus Infection 5
A. Nonspecific, Passive Defense Mechanisms 5
B. Nonspecific Active Defense Mechanisms 6
The Plasma Exudate 6
The Cellular Inflammatory Response 6
Inflammatory Mediators 7
In Vitro Experiments 8
Studies on Experimentally Induced Common Cold 9
Studies on Naturally Acquired Common Cold 10
C. Specific, Active Immune Defense Mechanisms 11
The Cellular Immune Response 11
The Humoral Immune Response 12
IV. Conclusion 13
References 14
I. Introduction
An upper respiratory tract infection or common cold is characterized by rhino-
rrhea, nasal congestion, and sneezing, sometimes accompanied by fever, sore
throat, and malaise. It is one of the most frequent infectious diseases in man (1).
Throughout our lifetime, we spend between 1 and 2 years suffering from a cold
(2). Especially, preschool children often (approximately 6 up to 12 times a year)
suffer from an upper respiratory tract infection, while the incidence decreases
with age and averages two to three common colds a year in adolescents and
adults (3). Although these infections are generally mild and self-limiting, they
account for a big economical burden due to high medical costs and high morbid-
ity. Each year, US physicians are consulted for an upper respiratory tract infec-
tion about 27 million times and almost $2 billion are spent on over-the-counter
medications for treatment of common cold symptoms (4). In addition, approxi-
mately 26 million days of school absence annually have been attributed to an
upper respiratory tract infection (3).
