Question

The initial evidence suggesting that opioid receptors are expressed by cells of the immune system was: a. Results showing impairment of \(\mathrm{T}\) cells to rosette to sheep red blood cells in the presence of morphine. b. Studies examining functions of the \(\mathrm{CB} 1\) and \(\mathrm{CB} 2\) receptors. c. Primate studies examining disease incidence in selfadministration of heroin d. Biochemical analyses of lymph nodes in heroin addicts. e. Studies showing increased HIV infection in heroin abusers.

Short answer

Answer: Results showing impairment of T cells to rosette to sheep red blood cells in the presence of morphine.

Step-by-step solution

Option A - Impairment of T cells

The main topic is about the initial evidence suggesting that opioid receptors are expressed by cells of the immune system. Option A refers to the result of an experiment where T cells struggled to perform their function (rosetting to sheep red blood cells) in the presence of morphine, which is an opioid. This option seems like a potential answer, as it directly relates to opioid receptors and their effect on immune cells.

Option B - CB1 and CB2 receptors

This option talks about studies examining functions of CB1 and CB2 receptors. However, these receptors are not opioid receptors but are instead cannabinoid receptors. Since this option refers to receptors unrelated to the main subject, it can be eliminated as an incorrect answer.

Option C - Primate studies

Although this option mentions heroin, which is an opioid, it focuses on disease incidence in primates due to self-administration of heroin. This answer choice does not provide any information about the presence of opioid receptors on immune system cells. Thus, this option can also be ruled out.

Option D - Lymph nodes in heroin addicts

Analyzing lymph node biochemistry in heroin addicts does not directly point to evidence showing that opioid receptors are expressed by cells of the immune system. It might provide secondary evidence, but it is not as direct as option A. It can also be ruled out.

Option E - HIV infection in heroin abusers

This option focuses on the correlation between HIV infection and heroin abuse. It does not directly provide evidence about opioid receptors being expressed by immune system cells. This answer choice can also be ruled out. Based on the analysis of each option, Option A is the most fitting answer to this multiple-choice question. So, the correct answer is: a. Results showing impairment of T cells to rosette to sheep red blood cells in the presence of morphine.

Key concepts

T cells function

T cells are a critical component of the adaptive immune system. Their primary function is to protect the body against pathogens and abnormal cells.

One of the functions of T cells is to recognize and latch onto antigens presented on the surface of infected or cancerous cells. This process is often compared to the 'rosetting' technique, where T cells are observed for their ability to surround and bind to a target like petals around the core of a flower. When T cells function properly, they activate and proliferate, producing various responses such as cytotoxic activity to kill infected cells or aiding in the production of antibodies by B cells.

However, certain substances can impair T cell function. The textbook problem indicates that the presence of morphine, an opioid, can affect T cells, suggesting a link between opioid receptors on immune cells and impaired immune function.

Opioid impact on immunology

Opioids, commonly known for pain relief, have significant impacts on the immune system as well. These substances can interact with opioid receptors located not just in the nervous system, but also on immune cells.

The activation of these receptors can lead to various immunomodulatory effects. In some cases, opioids can suppress the immune response by inhibiting the activity and proliferation of immune cells such as T cells, as well as impacting cytokine production and antibody response.

This immunosuppressive effect may make the body more susceptible to infections and reduce the efficacy of the immune system's ability to fight diseases. It's an important area of study since opioids are widely used in clinical settings for pain management, and understanding these effects is crucial for patient care.

Neuroimmune pharmacology

Neuroimmune pharmacology is an interdisciplinary field exploring the link between the nervous system, immune system, and pharmacology. This area of research is particularly focused on how drugs, including opioids, affect neuroimmune communication.

Opioid receptors on immune cells serve as a bridge between the nervous and immune systems. When opioids bind to these receptors, they can influence neuroimmune signaling pathways. This connection has far-reaching implications for the development and progression of various diseases, including chronic pain conditions and autoimmune disorders, and has generated interest in the development of drugs that can modulate neuroimmune interactions for therapeutic benefit.

Understanding this intricate relationship aids in creating more specific and effective treatments with fewer unintended effects on the immune system.