Host evolutionary “strategies”

• sickle-cell gene

  • over the course of human evolution, this has arisen five separate times near river deltas, where there are mosquitoes

  • sickle-shaped red blood cells prevent the organism from growing well

• Tay-Sachs disease

  • heterozygous state might inhibit growth of tuberculosis in lysosomes

• cystic fibrosis

  • heterozygous state might reduce fluid loss in diarrhea

• tuberculoid and lepromatous leprosy

  • tuberculoid: T_H1 response is effective and specific

  • lepromatous: T_H2 response is ineffective but specific—you make a lot of antibodies, but these antibodies don’t kill the organism. what means more to these T_H2 people than getting tuberculosis? possibly getting parasites

Category: Pathology Notes