Immune surveillance, and

The pathogenesis of AIDS (10,12,13) following HIV infection may be separated into primary and secondary effects. The primary effects are (/) quantitative and quahtative decreases in infected cells, ie, the T-lymphocytes (2) impaked cellular immunity (J) impaked immune surveillance and... 

Since the endogenous levels of inducible transcription factors like NF-kB and NFAT (Duh et al. 1989 Kinoshita et al. 1997) in these cells have been reported to be very low, HIV-1 promoter activation is inefficient resulting in non-expression of viral gene products (Figs. 5.1 and 5.2). Therefore, these cells can escape immune surveillance and act as passive carriers of HIV-1 for their natural lifespan. 

There exists direct evidence that the immune system mounts an immune response against most cancer types. Virtually all transformed cells express (a) novel surface antigens not expressed by normal cells or (b) express, at greatly elevated levels, certain antigens present normally on the cell at extremely low levels. These normal expression levels may be so low that they have gone unnoticed by immune surveillance (and thus have not induced immunological tolerance). 

Garcia-Lora, A., Algarra, L, and Garrido, E., 2003, MHC class 1 antigens, immune surveillance, and tumor immune escape, J. of Cell. Physiol. 195 346-355. 

Johnsen, A., Templeton, D. J., Sy, M. S., and Harding, C. V., 1999, Deficiency of transporter for antigen presentation (TAP) in tumor cells allows evasion of immune surveillance and increases tumorigenesis, J. Immunol 163 4224-4231. 

Sedgwick JD (1995) Immune surveillance and autoanUgen recognition in the cenUal nervous system. Aust N Z J Med 25 784—792. 

Virus-specific antibodies interfere with viral entry into host cells and opsonize the virus for elimination by macrophages however, they cannot eliminate the virus from infected cells. In addition, the humoral immune response can select HCV variants with seqnence changes that allow escape from antibody recognition. Antibodies to one genotype confer no resistance to another genotype. As a consequence of these factors, HCV is able to escape immune surveillance and establish persistent infection more readily. These characteristics of HCV also contribute to poor interferon response and make it difficult to develop a vaccine. Furthermore, the absence of an in vitro cell culture system has limited studies designed to screen newer antiviral compounds. 

Finally, the linear low-dose extrapolation obviates de facto the concept of a threshold in the dose-response curve. The threshold concept is universally accepted for most other, noncancer toxicity and for many other biological phenomena (e.g., taste thresholds), and many scientists would argue that such thresholds (or practical thresholds ) should apply to the cancer or mutation response due to the undo-lying complexities in toxicokinetics and in the dynamics of DNA damage and repair, immune surveillance, and the variation in the progression of clinical diseases. ... 

There are large numbers of latently infected CD4+ lymphocytes and macrophages in which HIV can persist and be disseminated despite immune surveillance. (and this) underscores the difficulties in designing treatment programmes.... Equally difficult is the problem of designing a vaccine to interdict the spread of HIV by a Trojan horse mechanism, concealed inside covertly infected cells . 

A functional immune system requires constitutive leukocyte trafficking to support immune surveillance, and acute massive localized leukocyte recmitment to respond to physical stress. Chemokines and their receptors support both of these... 

Rasnick D. Aneuploidy theory explains tumor formation, the absence of immune surveillance, and the failure of chemotherapy. Cancer Genet Cytogenet. 2002 136 66-72. 

The CXCR3 chemokine receptor and its ligands may also prove to be important targets for therapeutic interventions. Because of its role in immune surveillance and T-cell function, CXCR3 is implicated as a mediator of acute allograft rejection (Hancock et al, 2000) and complications in... 

RickUn D, HajishengaUis G, Yang K, Lambris JD. Complement a key system for immune surveillance and homeostasis. Nat Immunol 2010 1 785—97. 

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