Host Susceptibility and Resistance Genes

HLA proteins are essential for presenting antigens to T cells, which triggers an adaptive immune response.

A superantigen non-specifically cross-links HLA class II and T cell receptors, leading to excessive T cell activation.

The high polymorphism of HLA class II allows for a diverse range of antigen presentation, enhancing immune response variability.

<p>It can lead to excessive cytokine production, systemic inflammation, organ damage, and potentially death.</p> Signup and view all the answers

<p>Group A streptococci produce superantigens that can lead to severe immune reactions.</p> Signup and view all the answers

<p>Certain HLA haplotypes confer increased resistance to superantigen-mediated effects, making individuals less vulnerable.</p> Signup and view all the answers

<p>HLA class II is primarily expressed on antigen-presenting cells, such as macrophages.</p> Signup and view all the answers

<p>The crucial interaction involves the binding of HLA class II to T cell receptors (TCR).</p> Signup and view all the answers

<p>Common symptoms include burning stomach pain, nausea, vomiting, inflammation, and bleeding.</p> Signup and view all the answers

<p>Helicobacter pylori is primarily transmitted through oral-oral or fecal-oral routes.</p> Signup and view all the answers

<p>H. pylori uses flagella to move through the stomach's mucus and attaches to epithelial cells.</p> Signup and view all the answers

<p>Helicobacter pylori infection is associated with an increased risk of developing gastric cancer.</p> Signup and view all the answers

<p>Approximately two-thirds of the human population carries H. pylori without experiencing symptoms.</p> Signup and view all the answers

<p>Initial treatments included antacids and dietary adjustments.</p> Signup and view all the answers

<p>The discovery revealed that stomach ulcers were not solely caused by stress and diet but rather by bacterial infection.</p> Signup and view all the answers

<p>The microbiome may influence the host's immune response, affecting susceptibility to H. pylori.</p> Signup and view all the answers

<p>The researchers Barry Marshall and Robin Warren discovered H. pylori in 1983 and won the Nobel Prize in 2005.</p> Signup and view all the answers

<p>Common symptoms include abdominal pain, bloating, and nausea.</p> Signup and view all the answers

<p>H. Pylori is primarily transmitted through oral-oral or fecal-oral routes.</p> Signup and view all the answers

<p>H. Pylori uses its flagella to burrow into the stomach lining, allowing it to evade stomach acid.</p> Signup and view all the answers

<p>H. Pylori infection is linked to an increased risk of gastric cancer due to chronic inflammation.</p> Signup and view all the answers

<p>Host susceptibility can vary due to genetic factors, such as polymorphisms in HLA class II genes.</p> Signup and view all the answers

<p>Common symptoms include abdominal pain, bloating, nausea, and loss of appetite.</p> Signup and view all the answers

<p>H. pylori is primarily transmitted through oral-oral or fecal-oral routes.</p> Signup and view all the answers

<p>H. pylori adheres to the gastric epithelium, evading acid damage and eliciting an inflammatory response.</p> Signup and view all the answers

<p>Chronic inflammation from H. pylori infection can result in changes to gastric cells, increasing cancer risk.</p> Signup and view all the answers

<p>While CCR5 is primarily studied in relation to HIV, its role in innate immunity may influence infections like H. pylori.</p> Signup and view all the answers

<p>Certain genetic markers, like polymorphisms in the vitamin D receptor, can influence susceptibility.</p> Signup and view all the answers

<p>Virulence determinants, such as toxins and adhesion factors, enhance H. pylori's ability to colonize and damage host tissues.</p> Signup and view all the answers

<p>Host resistance genes can modulate immune responses, influencing the severity and chronicity of the infection.</p> Signup and view all the answers

<p>Common treatments include a combination of antibiotics and proton pump inhibitors.</p> Signup and view all the answers

<p>Urease helps H. pylori neutralize stomach acid, creating a more hospitable environment for colonization.</p> Signup and view all the answers

<p>Common symptoms of SARS include dry cough, labored breathing, and in severe cases, pneumonia.</p> Signup and view all the answers

<p>SARS primarily spreads through close person-to-person contact.</p> Signup and view all the answers

<p>The SARS coronavirus infects host cells by binding to receptors on the cell surface and entering the cell.</p> Signup and view all the answers

<p>There is no direct association between SARS and gastric cancer documented in the provided information.</p> Signup and view all the answers

<p>Host susceptibility influences severity based on factors like age, existing health conditions, and immune response.</p> Signup and view all the answers

<p>Asymptomatic patients can spread SARS unknowingly, making it challenging to contain outbreaks.</p> Signup and view all the answers

<p>SARS quickly became a global epidemic, spreading to over 24 countries within a short period.</p> Signup and view all the answers

<p>Severe infections of SARS can lead to pneumonia and may require mechanical ventilation.</p> Signup and view all the answers

<p>SARS first emerged in November 2002 in China.</p> Signup and view all the answers

<p>The outbreak spread internationally when a doctor from Guangdong infected several individuals in a Hong Kong hotel.</p> Signup and view all the answers