Coevolution of Innate and Adaptive Immunity
Peter Parham, Peter Parham in The Immune System, 2014
For much of the twentieth century, the community of immunologists was split into a minority who studied innate immunity, usually called inflammation, and a majority who studied adaptive immunity. This division originated with differences in concepts and methods, but then continued on the basis of precedent despite increasing evidence for connections between innate and adaptive immunity. The most important of these connections was the universal observation that an inflammatory response is a necessary prelude to making good antibodies. Although implemented in practice, this well-known fact was conveniently ignored in the thinking of most immunologists. That is, until the 1990s when the conceptual wall came down and the essential cooperation between innate and adaptive immunity was generally acknowledged.
IgE-Mediated Immunity and Allergy
Peter Parham, Peter Parham in The Immune System, 2014
The protective functions of immune defense are built upon mechanisms for distinguishing the constituents of infectious agents from the constituents of the human body. The immune system is thus able to be tolerant of self but recognize that pathogens and their antigens are foreign. Apart from infectious agents, humans come into daily contact with numerous macromolecules that are equally foreign but do not in any way threaten their health. Many of these potential antigens derive from the plants and animals that provide our food or are present in the environments where we live, work, and play. For most people for most of the time, contact with these molecules stimulates neither inflammation nor adaptive immunity. In these circumstances the immune system is seen to distinguish what is dangerous from what is not.
Innate Immunity in HIV Infection
Flossie Wong-Staal, Robert C. Gallo in AIDS Vaccine Research, 2002
Innate immunity is an ancient host defense system for the recognition of microorganisms (1). It is the first line of defense and functions during the early phase of infection, before the development of specific adaptive immune responses. The innate immune cells initially have effector functions, but act later as regulatory cells in adaptive immunity. Unlike the mechanisms of adaptive immunity, the innate immune cells do not use cell-surface immunoglobulins or T-cell receptors, they are not major histocompatibility complex (MHC) restricted and lack memory, which is essential in vaccination. An early, nonspecific protective response may limit microbial replication and dissemination, which allows adaptive immunity sufficient time to mount an effective protective response. The innate immune system can be characterized by a number of general features, which will be highlighted below (2,3). However, the role of innate immunity in controlling HIV infection has so far received only limited attention.
Evaluation of the establishment of herd immunity in the population by means of serological surveys and vaccination coverage
Published in Human Vaccines & Immunotherapeutics, 2012
The necessary herd immunity blocking the transmission of an infectious agent in the population is established when the prevalence of protected individuals is higher than a critical value, called the herd immunity threshold. The establishment of herd immunity in the population can be determined using the vaccination coverage and seroepidemiological surveys. The vaccination coverage associated with herd immunity (Vc) can be determined from the herd immunity threshold and vaccine effectiveness. This method requires a vaccine-specific effectiveness evaluation, and it can be used only for the herd immunity assessment of vaccinated communities in which the infectious agent is not circulating. The prevalence of positive serological results associated with herd immunity can be determined from the herd immunity threshold, in terms of prevalence of antibodies (pc) and serological test performance. The herd immunity is established when the prevalence of antibodies is higher than pc. This method can be used to assess the establishment of herd immunity in different population groups, both when the infectious agent is circulating and when it is not possible to assess vaccine effectiveness. The herd immunity assessment in Catalonia, Spain, showed that the additional vaccination coverage required to establish herd immunity was 3–6% for measles, mump and varicella and 11% poliovirus type III in school children, 17–59% for diphtheria in youth and adults and 25–46% for persussis in school children, youth and adults.
Immunology for veterinary nurses – humoral immunity
Published in Veterinary Nursing Journal, 2012
ABSTRACT: The immune system is split into innate and acquired immunity, with acquired immunity being further divided into humoral and cell-mediated immunity (CMI). Humoral immunity involves antibodies, of which there are five types. Antibodies are important for helping destroy antigens in a range of ways and are produced by B-lymphocytes. Humoral immunity and CMI work together to protect the animal, with components of CMI being essential for mediation of the acquired immune system. Humoral immunity can be measured using serological tests, which have applications in disease diagnosis and assessment of the need for revaccination.
Transient effect of cyclophosphamide on vaccinal immunity to Marek's disease
Published in Avian Pathology, 1978
L.N. Payne, M.C. Rennie, P.C. Powell, J.G. Rowell
Summary Cyclophosphamide treatment of chicks abrogated the induction of immunity against Marek's disease (MD) by the herpesvirus of turkeys, but immunity eventually developed if a sufficient interval was allowed to elapse between vaccination and challenge. Vaccinated, cyclophosphamide‐treated chicks showed severe suppression of antibody and immunoglobulin production even when immunity to MD was present, suggesting that resistance was not mediated by humoral immunity. Bursa and thymus weights of chicks were markedly reduced 7 days after treatment with cyclophosphamide, but at 35 and 70 days the mean weight of the thymus, but not of the bursa, was considerably restored. The results suggest that cyclophosphamide interferes with vaccinal immunity by an effect on the thymus and cell‐mediated immunity, and not by an effect on the bursa and humoral immunity.
Related Knowledge Centers
- Adaptive Immune System
- Humoral Immunity
- Innate Immune System
- Infection
- Immune System
- Disease
- Cell-Mediated Immunity