alternative strategies for infectious disease treatment Flashcards
what are the conventional treatments for infectious diseases?
its usually drugs which are given orally and are cheap, ideally with a short doing regime (once) with no adverse side effects
what are the alternative strategies for disease treatment?
vaccination and passive transfer of antibodies
what do vaccines do?
they produce a protective antigen in the vaccinated person to prevent the disease
they can give lifelong specific immunity as specific immune response has memory
what are classical vaccinations?
they are attenuated organisms, killed organisms, purified compounds but many arent moral as they give side effects
what are new generational vaccines?
they’re purified sub-components, recombinant antigens, live infectious vectors and DNA vaccines
what is prevented by classical vaccines?
BCG, vaccinia, MMR and polio
what is prevented by new-generation vaccines?
- purified sub-units: influenza haemagglutinin and neuraminidase
- recombinant antigens: hepatitis A and B surface antigens
- synthetic peptides: virus specific protein VP1 (foot and mouth disease)
- live infectious vectors: BCG, vaccinia and an avirulent salmonella
also Covid
what is the passive transfer of antibodies?
its also been known as ‘serum therapy’
it is when antibodies specific to a particular pathogen are administered early in the disease to help treat it
what are alternative therapies for disease treatment?
- treatment with t-cells
2. cytokine based therapies
what is treatment with t-cells used for?
- its used to treat cancer and uses the body’s
- cells these cells are then incubated with tumour specific antigen
- this increases the population of tumour specific t-cells in the body
- this is known as personalised medicine
what are the steps of CAR t-cell therapy?
- remove blood form the patient to get t-cells
- make CAR t-cells in the lab
- grow millions of CAR t-cells in the lab
- infuse CAR t-cells into the patient
- CAR t-cells then bind to the cancer cells and kill them
what does CAR in CAR t-cell therapy stand for? and what are they?
chimeric antigen receptors
theyre t-cells engineered to attach to a specific receptor on a persons body cell
how do CAR t-cells kill cancer cells?
their use is associated with the novel inflammatory process known as cytokine release syndrome
what do the ‘second generation’ CARs t-cells have a costimulatory domain derived from?
its derived from CD28 or CD137 (also known as 4-1BB) and CD3 zeta
what type of cancer are patients most likely to die from?
R/R B-cell acute lymphoblastic leukemia
what are the remission rates for CAR t-cell therapy?
67-90% for adults and paediatric patients R/R cancer who are given second-generation anti- CD19 CAR t-cells
what are cytokines?
they are proteins that can act as messengers between cells
cells produce a variety of cytokines that act on other kinds of cells to induce an immune response
they’re produced as recombinant proteins
in a viral infection, what 3 things must the immune system protect against?
- the virions
- the toxins (but not all viruses produce toxins)
- the viral infected cells
name 3 viruses that cause pathogenic infections in people?
- Covid-19
- HIV
- influenza
name 2 bacteria that cause pathogenic infections in people?
slamonella snd TB
name 2 bacteria that cause pathogenic infections in people?
slamonella snd TB
what are pathogenic infections?
they are infections caused by organisms which cause disease
name 3 examples of parasitic pathogens?
roundworms
hookworms
malaria
how can parasites be killed by macrophages?
- they are engulfed by them (phagocytosis)
- interferon-gamma from natural killer cells, CD4 + t-cells and CD8 + t-cells
they produce nitric oxide and superoxide-reactive nitrogen/ reactive oxygen species that damage pathogenic organisms - damages the structural integrity of organisms - they produce enzymes that digest pathogen inside phagolysomes
how can parasites be killed by macrophages?
- they are engulfed by them (phagocytosis)
- interferon-gamma from natural killer cells, CD4 + t-cells and CD8 + t-cells
they produce nitric oxide and superoxide-reactive nitrogen/ reactive oxygen species that damage pathogenic organisms - damage the structural integrity of organisms - they produce enzymes that digest pathogens inside phagolysosomes
what soluble proteins in the blood can act as opsoinin for macrophages?
- antibodies
- compliment
what decides the type of immune response to a pathogen?
- the pathogen
- how it infects,
- where its found in the body
- how it interacts with the hosts immune system
what are the structures on pathogens that are recognised as foreign by innate cells called?
PAMPs (pathogen associated molecular patterns)
what are the main phagocytic cells in people?
- macrophages
- neutrophils - there are billions in the body
what is a vaccine and what can it be made from and give one example of a clinical vaccine?
- a vaccine is something which induces a specific immune response and protects an individual from disease
- its made from antigens from the pathogenic organism in order to immunise someone
- it can be made from DNA, RNA, proteins or carbohydrates
- examples of classical vaccines are influenza, polio and hepatitas A
who discovered the first vaccine and what did it protect against?
- edward jenner, ot protected against smallpox
- he discovered it by deliberately infecting a little boy with cow pox and then exposing him to smallpox to see if he still caught it
- it protected him because of the cross-reacting antigens
what can be used to passively transfer immunity?
- antibodies are the type of immunity transferred
- in breast milk and through the placenta
- also in antiserum which is used to treat snake bites
what are cytokines?
give an example of a treatment using them?
theyre proteins produced by cells
interferon-alpha has been approved for the treatment of melanoma and blood cancers
how would you differentiate a virus pathogen from other types of pathogens?
theyre much smaller (10-400nm)
the genetic material can be DNA or RNA
its an intracellular pathogen
to may also have a protein coat and a causule of lipid and carbohydrate
