Recognition of the HLA class II-peptide complex by T-cell receptor: reversal of major histocompatibility complex restriction of a T-cell clone by a point mutation in the peptide determinant

Computational comparison of T-cell epitopes of gp120 of Iranian HIV-1 with different subtypes of the virus

In the present study, T-cell epitopes of gp120 of an Iranian isolate have been compared to different subtypes of HIV-1. At first, the amino acid sequences of gp120 were fetched from data banks. Then T-cell epitopes, disulfide bonding states, protein kinase C phosphorylation sites, cAMP-dependent protein kinase phosphorylation sites, casein kinase II phosphorylation sites, N-myristoylation sites and amidation sites were predicted using different soft wares. According to this computational analysis 6 good disulfide binding states in Iranian gp120 were predicted. From the viewpoint of cAMP-dependent protein kinase phosphorylation site (1 site) Iranian isolate was similar to clades B and F. Like subtype C 1 amidation site was predicted in the Iranian subtype. In the Iranian isolate 7 sites protein kinase C phosphorylation sites and 4 N-myristoylation sites were predicted. Since the number of individuals infected with HIV-1 in Iran, like many other countries is increasing, study of similarities and differences between the Iranian samples and different clades of HIV-1 can help us in identification of the origin and understanding the changes in the virus.

Immunization with a cannabinoid receptor type 1 peptide results in experimental allergic meningocerebellitis in the Lewis rat: A model for cell-mediated autoimmune neuropathology

Neuronal elements are increasingly suggested as primary targets of an autoimmune attack in certain neurological and neuropsychiatric diseases. Type 1 cannabinoid receptors (CB1) were selected as autoimmune targets because they are predominantly expressed on neuronal surfaces in brain and display strikingly high protein levels in striatum, hippocampus, and cerebellum. Female Lewis rats were immunized with N-terminally acetylated peptides (50 or 400 microg per rat) of the extracellular domains of the rat CB1 and killed at various time points. Subsequent evaluation using immunohistochemistry and in situ hybridization showed dense infiltration of immune cells exclusively within the cerebellum, peaking 12-16 days after immunization with the CB1 peptide containing amino acids 9-25. The infiltrates clustered in meninges and perivascular locations in molecular and granular cell layers and were also scattered throughout the CB1-rich neuropil. They consisted primarily of CD4(+) and ED1(+) cells, suggestive of cell-mediated autoimmune pathology. There were no inflammatory infiltrates elsewhere in the brain or spinal cord. The results show that neuronal elements, such as neuronal cell-surface receptors, may be recognized as antigenic targets in a cell-mediated autoimmune attack and, therefore, support the hypothesis of cell-mediated antineuronal autoimmune pathology in certain brain disorders.