Immune system, anti-infective drugs, and vaccines chp 9 & appendix B (Exam 4)

B lymphocytes

oversee humoral immunity

T lymphocytes

non-antibody-producing cells that constitute the cell-mediated arm of immunity

antigen-presenting cells (APCs)

play essential auxiliary roles in immunity

humoral response: antibodies

Also called immunoglobulins

Soluble proteins secreted by activated B cells and plasma cells in response to an antigen.

They are capable of binding specifically with antigens.

Simplest ammunition of the immune system.

They do not destroy antigen; they inactivate and tag it for destruction.

CD4 cells (T4 cells)

primarily helper T cell (T_H)

CD8 cells (T8 cells)

Cytotoxic T cells (T_c) that destroy cells harboring foreign antigens.

importance of cellular response

T cells recognize and respond only to processed fragments of antigen displayed on the surface of body cells.

helper T cell (T_H)

Regulatory cells that play a central role in the immune response.

Without T_H, there is no immune response.

Human Immunodeficiency Virus (HIV)

Virus can lead to acquired immune deficiency syndrome, or AIDS

HIV destroys CD4+ T cells, which are crucial to helping the body fight diseases.

Symptoms include fever, night sweats, weakness, diarrhea, weight loss, fatigue, and swollen glands.

HIV transmission

Contact with an infected individual.

Contaminated blood.

Used needles.

An infected mother transmits the virus to the fetus or a breastfeeding infant.

A single-stranded RNA viruses.

After entry, virally encoded reverse transcriptase converts RNA to double-stranded DNA.

Virus may become latent, and cells continue to function.

Virus becomes active and replicates.

how does HIV work?

nucleoside reverse transcriptase inhibitor drugs (NRTI)

Inhibit reverse transcriptase and prevents HIV from replicating

nucleotide reverse transcriptase inhibitor drugs (NtRTI)

Act the same was as NRTIs except contain a slightly different molecular structure.

A nucleotide is simply a nucleoside that is chemically linked to a phosphate group.

non-nucleoside reverse transcriptase inhibitor drugs (NNRTI)

Inhibits the protein domains of reverse transcriptase and prevents HIV from reproducing.

protease inhibitor drugs

Inhibit the viral enzyme protease.

Breaks down certain proteins in the virus.

It is an important last step that must happen before a virus can reproduce.

Without protease, HIV will only make immature particles that cannot infect other cells.

Common suffix -navir.

fusion inhibitor drugs

Block HIV when it tries to fuse its viral membrane with the cell membrane of the CD4 lymphocyte.

Because the virus cannot fuse with lymphocyte, it is unable to reproduce itself.

GP120 inhibitor drugs

Bind to gp120 subunit of the retrovirus and block it from attaching to lymphocyte’s CD4 receptor

integrase inhibitor drugs

Block integrase so the genetic material is not inserted into the genome.

cellular chemokine receptor (CCR5) antagonist drugs

Binds to and blocks cellular chemokine receptor (CCR 5 coreceptor) on the CD4 lymphocyte.

Only used for R5 strain of HIV.

post-attachment inhibitor drugs

Binds to domain 2 of CD4 and interferes with post-attachment steps.

treatment for viral infections

Antiviral drugs are used to treat infections caused by: Herpes simplex virus, Human papillomavirus, Cytomegalovirus, Influenza virus, Respiratory syncytial virus.

drugs for influenza virus infections

These antiviral drugs are used to prevent or treat influenza A or influenza B infections (the “flu”).

Common suffix -mivir

opportunistic infections

Candidiasis, Coccidioidomycosis, CMV retinitis, Histoplasmosis, Toxoplasmosis, Salmonella, Mycobacterium avium-intracellular infection, Pneumocystis pneumonia

fungi and yeast infections

It can cause disease topically or systemically.

They are opportunistic organisms. Grow most successfully when the patient’s immune system is already compromised or under stress.

Treated with the same antifungal (or antiyeast) drugs.

antifungal drugs

Binds to a specific receptor on the cell membrane of the fungus or yeast, changing the permeability of the membrane and causing the cellular contents to leak out.

Candidiasis

An extensive yeast infection that involves both the oral cavity and the esophagus.

Common in patients with AIDS.

Vaccines

Drugs produced and administered with the sole purpose of preventing the occurrence of a specific disease caused by bacterium or a virus.

forms of vaccines

Live but attenuated (weakened) bacteria or viruses.

Intact but inactivated (killed) bacteria or viruses.

Subunits

Toxoids

mRNA

Viral vector

malaria life cycle

Malaria parasites infection two types of hosts: humans and female Anopheles mosquitoes.

In humans, the parasites grow and multiply first in the liver cells and then in the red blood cells.

Releasing of daughter parasites (merozoites) that continue the cycle by invading other red cells.

Gametocytes are picked up by a mosquito, starting another cycle.

chloroquine

Quinoline anti-malarial agent.

Causes build up of toxic heme metabolic products in parasites and combines with oxygen to create reactive oxygen species, resulting in oxidative damage

problem with chloroquine

Widespread strains of chloroquine-resistant P. falciparum (the deadliest species of Plasmodium that causes malaria in humans).