During an immune response, professional antigen-presenting cells ( APCs ) endocytose foreign material ( typically bacteria or viruses ), which undergoes processing, then travel from the infection site to the lymph nodes.

The army then placed tanks and APCs on the road separating the Guru Nanak niwas building, thus forming a wall of iron.

In June 1969, an infantry company from 5 RAR, then on its second tour, and supported by a troop of tanks and a troop of APCs fought a significant combined-arms action against a battalion-sized force of NVA regulars and VC local force troops at the Battle of Binh Ba.

Support ( Boot ) Troop were initially equipped with Saracen and then CVR ( T ) Spartan APCs.

Professional APCs are very efficient at internalizing antigen, either by phagocytosis or by receptor-mediated endocytosis, and then displaying a fragment of the antigen, bound to a class II MHC molecule, on their membrane.

When a T < sub > h </ sub > cell encounters and recognises the antigen, on an APC, the TCR-CD3 complex binds strongly to the peptide-MHC complex present on the surface of professional APCs.

At the present time, infantry in the Finnish Army are designated either as infantry or Jäger troops, specifically mechanized infantry or motorised infantry using APCs or vehicles such as Sisu Nasu.

Dendritic cells ( DCs ), which are the primary antigen-presenting cells ( APCs ), of the donor tissue migrate to the recipient's peripheral lymphoid tissue ( lymphoid follicles and lymph nodes ), and present the donor's self peptides to the recipient's lymphocytes ( immune cells residing in lymphoid tissues ).

Most cells in the body can present antigen to CD8 < sup >+</ sup > T cells via MHC class I molecules and, thus, act as " APCs "; however, the term is often limited to those specialized cells that can prime T cells ( i. e., activate a T cell that has not been exposed to antigen, termed a naive T cell ).

By endocytosis or phagocytosis, exogenous antigens are taken into the antigen-presenting cells ( APCs ) and processed into fragments.

APCs are fundamentally different from the previously used armoured half-tracks in that they offer a higher level of protection from artillery burst fragments, and greater mobility in more terrain types.

T cells cannot bind native antigens, but require that they be processed by APCs, whereas B cells can be activated by native ones.

Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen presenting cells ( APCs ).

Some APCs also bind native ( or unprocessed ) antigens to their surface, such as follicular dendritic cells, but unprocessed antigens do not interact with T cells and are not involved in their activation.

The second signal involves an interaction between CD28 on the CD4 < sup >+</ sup > T cell and the proteins CD80 ( B7. 1 ) or CD86 ( B7. 2 ) on the professional APCs.

Several T cells subgroups can be activated by professional APCs, and each type of T cell is specially equipped to deal with each unique toxin or bacterial and viral pathogen.

The lymph nodes become a collection point to which APCs such as dendritic cells ( DCs ) can interact with T cells.

In this model CTLA 4 reverses the classic TCR-induced ‘ stop signal ’ needed for firm contact between T cells and antigen-presenting cells ( APCs ).

* The lymph transports antigen-presenting cells ( APCs ), such as dendritic cells, to the lymph nodes where an immune response is stimulated.

The principal functions of B-cells are to make antibodies against antigens, to perform the role of antigen-presenting cells ( APCs ), and to develop into memory B cells after activation by antigen interaction.

Class II MHC proteins are generally only found on the surface of specialised antigen-presenting cells ( APCs ).

MHC class II can be conditionally expressed by all cell types, but normally occurs only on professional antigen-presenting cells ( APCs ): macrophages, B cells, and especially dendritic cells ( DCs ).

The α-and β-subunits contains extracellular binding sites for peptides that are presented by the major histocompatibility complex ( MHC ) class I and class II proteins on the surface of antigen presenting cells ( APCs ).

Modern IFVs are well-armed infantry carriers, differencing from earlier APCs by their heavier armament allowing them to give direct-fire support during an assault.

The earliest armored personnel carriers ( APCs ) produced by Brazil, in the 1960s, benefited directly from some of the technology developed by Brazil's dynamic automotive industry.

* Gila APCs ( 6, intended for police use ; paid for by the Canadian government )

As of 2012, major equipment items reported by the IISS included ten T-55 tanks ( marked as potentially unserviceable ), 5 AMX-13 light tanks, 34 reconnaissance vehicles, 10 BMP-1 / 2 armoured infantry fighting vehicles, 41 wheeled APCs, and 36 + artillery pieces.

It is believed that the seized vehicles ( which included 15 Belgian Army Pandur APCs leased to Beninise army troops ) and parts have been used to equip the Military of Equatorial Guinea, and such seizure are considered by some as an act of piracy.

Some nations distinguish between mechanized and armored infantry, designating troops carried by APCs as mechanized and those in IFVs as armored.

Many APCs and IFVs currently under development are intended for rapid deployment by aircraft.

During the South African Border War, the Soviet RPGs used by SWAPO guerilllas and their Angolan supporters posed a serious threat to South Africa's lightly armored APCs, which could be easily targeted as soon as they stopped to disembark troops.

RPGs were used with great effect in the famous Battle of Vukovar by the Croatian army, during which more than 300 tanks, APCs and vehicles were put out of action.

In the course of the Battle of Grodno ( September 20 – September 22 ), the Red Army lost some hundred men ( by the Polish sources ; by the Soviet sources-57 killed and 159 wounded ) and also 19 tanks and 4 APCs destroyed or damaged.

This allowed the PLA to seize seven US-made M48A5 main battle tanks ( MBTs ) and a number of Staghound armoured cars, AMX-13 light tanks and M113 APCs for its own armoured corps, further strengthened in 1985 with the arrival of some 70 T-54 / 55 MBTs, BTR-152, BTR-60 and BMP-1 APCs supplied on loan by Syria and the USSR, which they employed in the War of the Camps waged that same year against Nasserite and PLO militias in west Beirut.

As of now BMD-1 and vehicles based on it are used by the following units of Russian Army or are stationed in following bases ( this list does not include BTR-D APCs and BTR-D variants ):

Achzarit APCs took part in Operation Rainbow in Rafah, after a comparatively lightly armored M113 APC was destroyed by an RPG.

Some 2500 Casspir series APCs were built by TFM of South Africa, which was subsequently taken over by Reumech OMC.

They were intended as a stop-gap vehicle for use until the first Panhard M3 VTT APCs entered service in 1972.

More sophisticated systems for tanks and APCs exist that use various techniques ( including scanning lasers and coupled radio systems ) to allow more precise targeting of armored vehicles.

A APCs are identified as IHC M5s by the use of RED-450 engines for the most part.

They were intended as a stop-gap vehicle for use until the first Panhard M3 VTT APCs entered service in 1972.