How does HIV make it harder for the body to fight infection?

Answer 1

There are a whole host of reasons, but essentially the answer emanates from the two main specific qualities the virus has that make it almost impossible for the body to become 'accustomed' to or 'immune' to, using the specific terms of the virus itself. These main two qualities are the significantly fast rate at which the virus reproduces - making it highly virulent. As well as the fact that the virus has a high rate of genetic mutation across its DNA structure. Essentially, the virus is reproducing at a rate which is unviable for it to be eliminated effectively. And ideally, it is mutating at a rate that makes it so significantly different to the original DNA structure that may have entered the body that the immune system cannot identify it over the broad spectrum of his manifestations in the body. The immune system is highly complex, and the following brief description is specifically intended to be just that, brief. The Immune system works simply on the basis of identifying certain antigens present on 'foreign molecules', it goes further in ascertaining the basic chemical structure of these foreign molecules and then has an 'immune-specific response' which involves the manufacturing of specific 'combat cells' and chemicals to target the invading molecules and eliminate them. Such cells include a variety of basic white blood cells such as lymphocytes, neutrophils and eisonophils. As well as more highly specific forms of cells including B and T cells, which themselves are sub-categorized into more specific functions such as cytotoxic or 'killer' cells and memory cells, which are designed to 'remember' the specific kind of invading molecule so that an immune response can be more rapid, specific and effective the next time the exposure to the molecule occurs.

Now, the answer to the question you have asked becomes much clearer now that we now the 'basics' given above of how the virus is extremely difficult to eliminate. The reason for the problem you have stipulated is 'relatively' simple. Basically, the HIV (virus) infects a range of the most basic cells the body uses in its immune response and defence against pathogenic and harmful molecules. If these cells are becoming impaired and targeted, their eventual efficacy will necessarily be reduced as they themselves are targeted, infected and rendered useless in such a way that they no longer become effective in the destruction of infectious molecules. The main immune cells that HIV infects are CD4 T cells, which are more colloquially known as 'Helper T cells', macrophages and microglial cells which are the macrophage-type cells present in the brain and spinal chord, but essentially with the same function. Helper T cells work not by cytotoxicity or 'the toxicity of a substance to a particular molecule' and i.e. work to inhibit its function or destroy it, but rather in the elicitation of the release of other more destructive cells such as 'Killer T cells'. Macrophages in short, work by engulfing the molecules in question within themselves, and 'dissolving' the foreign substances by digesting them within the internal endothelium of the cell (the cell boundary), commonly known as 'Phagocytosis'. HIV also has a relatively easy method for infection into these cells by a certain Chemokine (chemical involved in release of proteins within cells) CCR5 that allow it to cross into macrophages and 'Helper T cells' and reproduce extensively. So, in answer to your question, see below:

Coupled with the easy entry and replication within these specific cells, and the manner in which the virus can replicate extensively and mutate effectively all the time, the body is not able to destroy or eliminate the virus (as it keeps changing and growing in numbers). The manner in which it infects these specific cells, AND MORE IMPORTANTLY= the specific characteristics and functions that these specific cells have (defense against infection, viruses, pathogens, and foreign molecules in general) make the body almost completely unable to fight basic infections, cancerous growths, and other less problematic pathogenic introductions that would otherwise not be so harmful. Impairment of these defense cells, immune cells if you like, results in the body being unable to defend and "cope" with other infections.

Hope this helped.

Answer 2

it doesnt