Molecular characterization of a 13-amino acid deletion in VP1 (1D) protein and novel amino acid substitutions in 3D polymerase protein of foot and mouth disease virus subtype A/Iran87

The nucleotide sequence of the VP1 (1D) and partial 3D polymerase (3Dpol) coding regions of the foot and mouth disease virus (FMDV) vaccine strain A/Iran87, a highly passaged isolate (~150 passages), was determined and aligned with previously published FMDV serotype A sequences. Overall analysis of the amino acid substitutions revealed that the partial 3Dpol coding region contained four amino acid alterations. Amino acid sequence comparison of the VP1 coding region of the field isolates revealed deletions in the highly passaged Iranian isolate (A/Iran87). The prominent G-H loop of the FMDV VP1 protein contains the conserved arginine-glycine-aspartic acid (RGD) tripeptide, which is a well-known ligand for a specific cell surface integrin. Despite losing the RGD sequence of the VP1 protein and an Asp26-->Glu substitution in a beta sheet located within a small groove of the 3Dpol protein, the virus grew in BHK 21 suspension cell cultures. Since this strain has been used as a vaccine strain, it may be inferred that the RGD deletion has no critical role in virus attachment to the cell during the initiation of infection. It is probable that this FMDV subtype can utilize other pathways for cell attachment.

Glicoproteína del virus rábico: Estructura, inmunogenicidad y rol en la patogenia / Rabies vims glycoprotein: Structure, immunogenicity and pathogenic role

Rabies glycoprotein is the only exposed protein which is inserted in the viral lipidie envelope. This 65-67 kda protein is a N-glycosilated transmembrane protein forming trimers on the viral surface. It has been identified as the major pathogenicity determinant, playing a role in the budding, viral axonal transport during infection, apoptosis and immune evasion. It is also the major antigen responsible for the protective immune response and it is been used in commercial recombinant vaccines. Its structure, antigenicity and pathogenic role have been well studied, identifying main antigenic sites that have the responsibility for virulence, cellular receptors attachment and epitope acquisition.

La glicoproteína del virus rábico es la única proteína viral expuesta, encontrándose inserta en la envoltura lipídica. Esta molécula de 65-67 kda corresponde a una proteína trans-membrana N-glicosilada que se dispone en forma de trímeros en la superficie viral. Ha sido identificada como el mayor determinante de pato-genicidad, participando además en procesos de yemación, flujo axonal del virion durante la infección, apoptosis y evasión de la respuesta inmune. Es también el principal antígeno inductor de la respuesta inmune protectora siendo utilizado en vacunas recom-binantes comerciales. Su estructura, antigenicidad e implicancias en la patogenia han sido bien estudiadas identificándose los principales sitios antigénicos responsables de la patogenicidad, unión a receptores celulares y formación de epitopos.

Characterization of Antigenic Sites on the Rinderpest Virus N Protein Uusing Monoclonal Antibodies

The N protein of the rinderpest virus (RPV) was analyzed topologically and antigenically by using anti-N monoclonal antibodies (Mabs). Ten Mabs were raised against the N protein of the RPV. At least six non-overlapping antigenic sites (sites A-F) were delineated by competitive binding assays using biotinylated Mabs. Of them 5 sites (A, C, D, E and F) on the N protein were recognized by RPV-specific Mabs in ELISA and IFA while site B was recognized by Mabs reacting with both RPV and PPRV. Non- reciprocal competition was found among sites C, D and E. Recombinant RPV N protein after exposure to 0.2% SDS exhibited higher ELISA titers in all Mabs recognizing 6 sites. Four sites (A, B, E and F) on 2% SDS-treated N protein lost completely reactivity with Mabs while the remaining sites (C and D) on the protein retained their antigenicity to some degree. It indicates that two sites (C and D) were sequential. Six representative Mabs bound to each site exhibited competition with rinderpest antibodies in a blocking ELISA, indicating that the sites were actively involved in antigenicity in cattle.

Detection of HSV-2 antigen in carcinoma cervix and premalignant conditions by immuno-cytochemistry.

One hundred and twelve cases of cervical pathology (58 paraffin sections and 54 cervical smears) were assessed by PAP technique and 30 cases by indirect immunofluorescent technique. Forty-two normal cervical smears from the age matched controls were stained by indirect immuno-fluorescent technique. HSV-2 antigen was detected by PAP method in 86 out of 112 cases (78.57%) i.e. 50/55 squamous cell carcinoma, 13/13 carcinoma in situ, 11/15 severe dysplasia, 3/4 moderate dysplasia and 9/16 mild dysplasia. The amount of antigen was maximum in squamous cell carcinoma and decreased in carcinoma in situ, severe, moderate and mild dysplasia in descending order. Three cases of adenocarcinoma cervix were negative. Only one case out of 42 controls was positive. HSV-2 antigen was detected by an indirect IF technique in 8/9 squamous cell carcinoma, 2/3 carcinoma in situ, 3/7 dysplasia, O/1 adenocarcinoma and 4/10 inflammatory cases. The above findings support the association between HSV-2 and squamous cell carcinoma cervix, as well as carcinoma in situ which is statistically significant.