QUESTION 1 (maximum word limit is 800 words)
Humans have evolved an array of pattern recognition receptors including TLRs, RLRs, NLRs and CLRs. Many of these are highly conserved across species. Describe, from an immunological perspective, why so many different pattern recognition receptors are required, why they are so highly conserved across species and how they function collaboratively to activate innate immune responses. Provide specific examples.
Word Count: <insert word count here>
<write your response to this question here>
QUESTION 2 (out of 15 marks)
There has been an outbreak of Measles in parts of Sydney. Patients have been brought to the hospital with distinct signs and symptoms. Blood samples are collected at the hospital sent for analysis. To assess infection an ELISA was performed to look at the levels of IgG and IgM in the blood. The patient samples were not diluted to determine OD measurements (i.e. the patient OD values given are from neat/undiluted patient samples). As per the guidelines for the ELISA, a serum concentration of IgG or IgM < 0.9ug/mL is negative and a value of >1.1ug/mL is positive.
Diagnosis is made based on the table below;
| IgG | IgM | |
| Uninfected/Unvaccinated | Negative | Negative |
| Vaccinated | Positive | Negative |
| Early infection | Negative | Positive |
| Current/recent infection | Positive | Positive |
Results from ELISA:
IgG ELISA
| µg/ml of standard or patient sample | OD | |
| 4 | 0.592 | 0.611 |
| 2 | 0.312 | 0.31 |
| 1 | 0.215 | 0.195 |
| 0.5 | 0.153 | 0.149 |
| 0.25 | 0.103 | 0.108 |
| 0.125 | 0.091 | 0.088 |
| 0 | 0.073 | 0.081 |
| Patient 1 | 0.128 | 0.133 |
| Patient 2 | 0.223 | 0.215 |
| Patient 3 | 0.337 | 0.338 |
| Patient 4 | 0.119 | 0.12 |
IgM ELISA
| µg/ml of standard or patient sample | OD | |
| 4 | 0.823 | 0.807 |
| 2 | 0.428 | 0.436 |
| 1 | 0.23 | 0.261 |
| 0.5 | 0.146 | 0.161 |
| 0.25 | 0.113 | 0.144 |
| 0.125 | 0.083 | 0.093 |
| 0 | 0.074 | 0.077 |
| Patient 1 | 0.482 | 0.456 |
| Patient 2 | 0.078 | 0.081 |
| Patient 3 | 0.397 | 0.419 |
| Patient 4 | 0.105 | 0.11 |
Construct 2 standard curves from the above OD values by performing the following steps: (i) average the OD values for each of the concentrations of the standard protein, (ii) normalise the averaged OD values using the average of the 0 µg/ml samples (create a table to show your average and normalisation values), (iii) determine if any of the protein standard concentrations should not be used to construct the standard curve (provide an explanation why you have or have not removed any protein standards from the construction of the standard curve), and (iv) construct the standard curves. (4 marks)
<insert your standard curves and answers here>
- Determine the concentration of antibody in your patient samples. (2 marks)
<insert your answer here, include any working out steps leading to your answer>
- Are the OD values of all the patient samples appropriate to use to calculate the antibody concentration? Why/why not? If there are samples that are not ideal for calculation, what would you do in the future to be able to calculate the antibody concentrations? Can you still provide a diagnosis based on these OD values from the patient samples? Why/why not? (5 marks)
<insert your answer here>
- Provide a diagnosis of the 4 patients by completing the table below (4 marks):
| Patient # | Positive or negative result for: | Diagnosis | |
| IgG | IgM | ||
| 1 | |||
| 2 | |||
| 3 | |||
| 4 | |||
