An HIV encoded protein that if targeted therapeutically could result in the blocking of binding of HIV to T lymphocytes is

Correct Answer: E

Rationale: In this question, the correct answer is C) gp41. This protein is a component of the HIV envelope that plays a crucial role in the fusion of the virus with the host cell membrane. By targeting gp41 therapeutically, we can interfere with this binding process, preventing HIV from entering T lymphocytes and replicating within them. Option A) Reverse transcriptase (RT) is responsible for converting the viral RNA into DNA once the virus has entered the host cell, not for the initial binding process. Option B) Viral proteases are enzymes that cleave viral proteins into functional components but do not directly impact the binding of HIV to T lymphocytes. Option D) Matrix protein is involved in the assembly of the virus particle and not in the binding to host cells. Understanding the specific functions of these HIV proteins is essential for developing effective therapeutic strategies to combat the virus. By targeting gp41, researchers can potentially develop drugs that block HIV entry into host cells, thereby inhibiting viral replication and spread. This knowledge is crucial for students studying immunology, virology, and infectious diseases, as it highlights the importance of targeting specific viral components to design effective treatments.

Correct Answer: A

Rationale: The correct answer is A. Chronic granulomatous disease (CGD) is caused by mutations of the NADPH oxidase genes, leading to defective respiratory burst in neutrophils. Neutrophils are recruited to sites of infection normally in CGD. Therefore, choice A is incorrect. Choices B, C, and D are incorrect because CGD is indeed associated with defective respiratory burst of neutrophils due to mutations in NADPH oxidase genes, leading to recurrent bacterial infections.

Correct Answer: D

Rationale: The correct answer is D: Complement activation. Phagocytosis by macrophages involves engulfing and digesting pathogens. Complement activation occurs through a separate pathway involving a series of proteins that enhance the immune response. Phagocytosis does not directly lead to complement activation. Choices A, B, and C are outcomes of phagocytosis in macrophages: Respiratory burst involves production of reactive oxygen species, nitric oxide production helps destroy pathogens, and antigen presentation is important for activating other immune cells.

Correct Answer: D

Rationale: Passive immunization does not involve transferring naïve lymphocytes; instead, it transfers pre-formed antibodies for immediate protection. Choice D is incorrect because lymphocytes do not produce antibodies directly. Choices A, B, and C are correct: Passive immunization has been used for Ebola, transfers serum with antibodies, and provides immediate protection with pre-formed antibodies.

Correct Answer: D

Rationale: The Fc regions of antibodies interact with various immune cells and molecules to mediate effector functions. - A: Degranulation of mast cells: Fc receptors on mast cells bind to antibody Fc regions, triggering degranulation. - B: ADCC: Fc regions bind to Fc receptors on immune cells, facilitating target cell killing. - C: Complement activation: Antibody binding to antigens can activate the complement system via the Fc region. Therefore, the correct answer is D because the Fc regions of antibodies are involved in all mentioned effector functions.